ARTICLE | doi:10.20944/preprints202101.0068.v1
Subject: Medicine & Pharmacology, Allergology Keywords: cold plasma; plasma activated liquid; cancer cell; melanoma; fibroblast
Online: 5 January 2021 (10:04:48 CET)
Plasma medicine is a new field focusing on biomedical and clinical applications of cold physical plasmas, including their anticancer effects. Cold plasmas can be applied directly or indirectly as plasma activated liquids (PAL). The effect of plasma activated cell growth medium (PAM) and plasma activated phosphate buffered saline (PAPBS) were tested using a plasma pen generating streamer corona discharge in ambient air, on different cancer cell lines (melanoma A375, glioblastoma LN229 and pancreatic cancer MiaPaCa-2) and normal cells (human dermal fibroblasts HDFa). The viability reduction and apoptosis induction were detected in all cancer cells after incubation in PAL. In melanoma cells we focused on detailed insights to the apoptotic pathways. The anticancer effects depend on the plasma treatment time or PAL concentration. The first 30 minutes of incubation in PAL were enough to start processes leading to the cell death. In fibroblasts, no apoptosis induction was observed, only PAPBS, activated for longer time, slightly decreased their viability. Anticancer effects of PAM and PAPBS on cancer cells showed selectivity compared to normal fibroblasts, depended on correctly chosen activation time and PAL concentration. This selectivity, supported by optimum ratio of hydrogen peroxide and nitrites in PAL, is very promising for potential clinical applications.
COMMUNICATION | doi:10.20944/preprints202004.0126.v1
Subject: Life Sciences, Biophysics Keywords: Cold atmospheric Plasma; sterilization; Plasma-activated medium; Nitric oxide; Immunotherapy; COVID-19
Online: 8 April 2020 (11:34:11 CEST)
The recent pandemic has greatly stressed supply chains, treatment modalities, and medical resources. Cold atmospheric plasma (CAP) has been used for a wide range of applications in biomedical engineering due to its many components including electrons, charged particles, reactive oxygen species (ROS), reactive nitrogen species (RNS), free radicals, ultraviolet (UV) photons, molecules, electromagnetic fields, physical forces, and electric fields. In this manuscript, we develop CAP devices for COVID-19. Our manuscript indicates the advantages of highlydeployable CAP devices for both sanitation and treatment, without the need for supply chains of special consumables such as hand sanitizers and the like. We hope that this timely research will help engage the broader community of engineers that wish to help the medical community with this pandemic and to prevent and treat future outbreaks.
ARTICLE | doi:10.20944/preprints202107.0091.v1
Subject: Physical Sciences, Acoustics Keywords: Relativity; Gravitation Lensing; Kazakov-Solodukhin black hole; Gauss-Bonnet Theorem; Deflection angle; Plasma medium
Online: 5 July 2021 (10:48:57 CEST)
In this paper, we study light rays in a Kazakov-Solodukhin black hole. To this end, we use the optical geometry of the Kazakov-Solodukhin black hole within the Gauss-bonnet theorem. We first show the effect of the deformation parameter $a$ on the Gaussian optical curvature, and then we use the modern method popularized by Gibbons and Werner to calculate the weak deflection angle of light. Our calculations of deflection angle show how gravitational lensing is affected by the deformation parameter $a$. Moreover, we demonstrate the effect of a plasma medium on weak gravitational lensing by the Kazakov-Solodukhin black hole. We discuss that the increasing the deformation parameter $a$, will increase the weak deflection angle of the black hole. Our analysis also uncloak how one may find a observational evidence for a deformation parameter on the deflection angle.
ARTICLE | doi:10.20944/preprints202012.0025.v1
Subject: Physical Sciences, Acoustics Keywords: plasma-liquid interactions; water electrospray; aerosol microdroplet; bulk water, plasma-activated water; Henry’s law solubility; ozone; hydrogen peroxide
Online: 1 December 2020 (13:16:22 CET)
Production and transport of reactive species through plasma-liquid interactions plays a significant role in multiple applications in biomedicine, environment, and agriculture. We experimentally investigated the transport mechanisms of hydrogen peroxide H2O2 and ozone O3, as the typical plasma species, into water. We measured the solvation of gaseous H2O2 and O3 in airflow into water bulk vs. electrosprayed microdroplets while changing the gas and water flow rates, applied voltage that determines the gas-liquid interface area, and treatment time. The solvation rate of H2O2 and O3 increased with the treatment time and the gas-liquid interface area. The total surface area of the electrosprayed microdroplets was larger than that of the bulk, but their lifetime was much shorter. We estimated that only microdroplets with diameters below ~ 40 µm could achieve the saturation by O3 during their lifetime, while the saturation by H2O2 was impossible due to its depletion from air. Besides the short-lived flying microdroplets, the longer-lived bottom microdroplets substantially contributed to H2O2 and O3 solvation in water electrospray. This study contributes to a better understanding of the gaseous H2O2 and O3 transport into water as a function of different parameters and will lead to design optimization of the plasma-liquid interaction systems.
REVIEW | doi:10.20944/preprints202102.0346.v1
Subject: Materials Science, Polymers & Plastics Keywords: Activated carbon; Adsorbance; Pyrolysis; Applications
Online: 17 February 2021 (09:15:00 CET)
Actuated carbon (AC) is utilized in various conditions of uses after its disclosure as a solid and dependable adsorbent. A review on AC is introduced along with returning to the wellsprings of AC age; strategies used to produce AC including pyrolysis enactment; actual actuation; synthetic initiation and steam pyrolysis. The significant variables influencing the AC creation, the potential uses of AC and their future possibilities are likewise examined. AC is applied in water, wastewater and leachate medicines in numerous nations, particularly to clean the shading, eliminate the smell and some substantial metals. Taking into account this, an exhaustive rundown of research on compound, physical and organic change strategies of initiated carbon relating to prevent of foreign substance expulsion from watery arrangements was aggregated and investigated. Additionally, the examination of the actual blending strategy and the impregnation technique in enactment with antacid metals shows that the actuated carbon got through actual blending had a higher porosity than the initiated carbon created by the impregnation technique. The uses of initiated carbon items were quickly surveyed.
REVIEW | doi:10.20944/preprints201810.0061.v1
Subject: Physical Sciences, Fluids & Plasmas Keywords: Plasma Generation Techniques, Applications of Plasma; Fusion technology; Plasma ion implantation and Deposition.
Online: 3 October 2018 (15:54:34 CEST)
Plasma being the fourth and most abundant form of matter extensively exists in the universe in the inter-galactic regions. It provides an electrically neutral medium of unbound negative and positive charged particles, which has been produced by subjecting air and various other gaseous mixtures to strengthen the electromagnetic field and by heating compressed air or inert gasses for creating negative and positive charged particles known as ions. Nowadays, many researchers are paying attention to the formation of artificial Plasma and its potential benefits for mankind. The literature is sparsely populated with the applications of Plasma. This paper presents specific methods of generation and applications of Plasma, which benefits humankind in various fields, such as in electrical, mechanical, chemical and medical fields. These applications include hydrogen production from alcohol, copper bonding, semiconductor processing, surface treatment, Plasma polymerization, coating, Plasma display panels, antenna beam forming, nanotechnology, Plasma Torch, Plasma pencils, low-current non-thermal Plasmatron, treatment of prostate cancer, Plasma source ion implantation, cutting by Plasma, Plasma etching, pollution control, neutralization of liquid radioactive waste, etc. Resultantly, worth of Plasma technology in the medical industry is increasing exponentially that is closing the gap between its benefits and cost of equipment used for generating and controlling it.
ARTICLE | doi:10.20944/preprints201909.0185.v1
Subject: Materials Science, Metallurgy Keywords: activated carbon; adsorption; copper; winemaking wastes
Online: 17 September 2019 (11:44:45 CEST)
This article presents the copper ions adsorption process using an activated carbon from winemaking wastes. The pH, temperature, activated carbon amount and initial copper concentration were varied based on a full factorial 2k experimental design. Kinetic and thermodynamic studies were also carried out. The adsorption kinetics was found follow a pseudo-second-order model. The adsorption data fit better to the Langmuir isotherm. The ANOVA demonstrated that both pH of the solution and activated carbon dosage had the greatest influence on copper adsorption. The activation energy was -32 kJ·mol-1 suggesting that the copper adsorption is a physic-sorption process. The best fit to a linear correlation was the moving boundary equation that controls the kinetics for the adsorption copper ions onto the activated carbon. The X-ray photoelectron spectroscopy (XPS) results reveal the existence of different copper species (Cu2+, Cu+ and or Cu0) on the surface of the carbonaceous adsorbent after the adsorption, which could suggest a simultaneous reduction process.
ARTICLE | doi:10.20944/preprints201710.0005.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Biodegradation; fats and oils; activated sludge
Online: 2 October 2017 (08:51:14 CEST)
Fats and oils are the most common contaminants in wastewater and are usually discarded through physical processes. This paper studies its elimination through an environmentally friendly biological treatment, yielding good results on both laboratory scale and in the field. In this study a comparative evaluation of the biodegradation of fats and oils in two scenarios were developed in an activated sludge plant at laboratory scale, and a wastewater treatment plant. The full-scale values for some key parameters are compared, such as the oil concentration in the influent and effluent, mass loading and removal efficiency and biodegradation systems. Activated sludge plant at laboratory scale working on a mass load range from 0.2 to 0.8 (kg COD / day / kg MLSS) initially reaches levels of 75% biodegradation thereafter influent concentration is increased and thereby the mass load is increased in a range of working system under high load and biodegradation rates ranging from 71 to 64% are achieved. The actual system consists of a treatment plant wastewater with an aerobic digester for sludge treatment. Fats and oils are retained in a previous degreaser to biological treatment and subsequently sent to the aerobic sludge digester, constituting of thus on a single substrate, resembling an activated sludge plant with extended aeration mode, and levels of biodegradation in the range of 69 to 92%. From this work, we can say that the choice of biological treatment for fats and oils is feasible and adequate. Furthermore, the biomass presents great adaptability to the oil substrate, favored in this case for being the only source of carbon, therefore fats and oils should be removed using biological treatment, instead of the flotation procedure or at most using it as an intermediate process
ARTICLE | doi:10.20944/preprints202003.0055.v1
Subject: Physical Sciences, Fluids & Plasmas Keywords: Beam dumps; laser plasma accelerator; plasma beam dump
Online: 4 March 2020 (09:45:00 CET)
Beam dumps are indispensable components for particle accelerator facilities to absorb or dispose beam kinetic energy in a safe way. However, the design of beam dumps based on conventional technology, i.e. the energy deposition via beam-dense matter interaction, makes the beam dump facility complicated and large in size, partly due to nowadays’ high beam intensities and energies achieved. In addition, these high-power beams generate radioactive hazards, which need specific methods to deal with. On the other hand, the EuPRAXIA project can advance the laser-plasma accelerator significantly by achieving 1-5 GeV high quality electron beam in a compact layout. Nevertheless, the beam dump based on conventional technique will still produce radiation hazards and make the overall footprint less compact. Here, we propose to implement a plasma beam dump to absorb the kinetic energy from the EuPRAXIA beam. In doing so, the overall compactness of the EuPRAXIA layout will not be impacted, and the radioactivity generated by the facility can be mitigated. In this paper, results from particle-in-cell (PIC) simulations are presented for plasma beam dumps based on EuPRAXIA beam parameters.
REVIEW | doi:10.20944/preprints201809.0072.v1
Subject: Engineering, Mechanical Engineering Keywords: photo-catalysis, suspension plasma spray, thermal plasma, titanium oxide
Online: 4 September 2018 (15:08:47 CEST)
As a photo-catalytic titanium oxide film deposition process, thermal spray is hoped to be utilized practically on the condition that it is relatively easy to deposit anatase rich films. However, because of its high equipment and feedstock powder costs, it is very difficult to introduce thermal spray equipment into small companies. In this study, to develop a low cost thermal spray system, low power atmospheric suspension plasma spray equipment with titanium hydroxide suspension created by hydrolysis of titanium tetra iso butoxide using Ar, N2 as working gases. For avoiding sedimentation of the hydroxide particles in the suspension, mechanical milling of the suspension was conducted to create colloidal suspension before using it as feedstock. Moreover, an Ultrasonic wave container was used to keep the suspension particles moving while the spray process was conducted. After the film deposition, with As for the coating, anatase rich TiO2 ﬁlm could be obtained. For characterization of the film, microstructure observation by optical microscope and X-ray diffraction was carried out. Consequently, by creation of colloidal suspension, deposition could be conducted without sedimentation of the hydroxide particle in the suspension during operation. Besides, it was proved the film had enough photo-catalytic property to decolor methylene-blue droplet
ARTICLE | doi:10.20944/preprints201908.0076.v1
Subject: Chemistry, Applied Chemistry Keywords: dysprosium; activated carbon; spent coffee ground; adsorption
Online: 6 August 2019 (12:23:23 CEST)
This paper describes the physico-chemical study of the adsorption of dysprosium (Dy3+) in aqueous solution onto two types of activated carbons synthesized from spent coffee ground. KOH activated carbon is a microporous material with a specific BET surface area of 2330 m2·g-1 and pores with a diameter of 3.2 nm. Carbon activated with water vapor and N2 is a solid mesoporous, with pores of 5.7 nm in diameter and a specific surface of 982 m2·g-1. A significant dependence of the adsorption capacity on the solution pH was found, while it does not depend significantly neither on the dysprosium concentration nor on the temperature. A maximum adsorption capacity of 31.26 mg·g-1 and 33.52 mg·g-1 for the chemically and physically activated carbons, respectively, were found. In both cases, the results obtained from adsorption isotherms and kinetic study were better fit to a Langmuir model and a pseudo-second-order kinetics. In addition, thermodynamic results indicate that dysprosium adsorption onto both activated carbons is an exothermic, spontaneous and favorable process.
Subject: Engineering, Other Keywords: perfluorinated compounds; coagulation; ozone; chlorination; activated carbon
Online: 9 May 2019 (13:00:57 CEST)
This study surveyed the variation in Perfluorinated Compounds (PFCs) concentration entering urban wastewater treatment plants and proposed an optimal PFCS treatment method. The PFCS concentration in influent was shown to be affected by the types of industries and operating rate. The concentration of PFCs in the wastewater treatment effluent was slightly lower than that of influent. Thus, PFCs were considered to have barely been removed by the existing biological treatments. The pilot test result showed that about 10% of PFCs were removed by coagulation and precipitation, and the ozone and chlorine test also showed that few PFCs were removed regardless of the amount of injection. The activated carbon adsorption test showed that the removal was significantly increased by the empty bed contact time, with about a 60% removal in five minutes and over a 90% removal in 15 minutes. Therefore it is determined that a more stable and higher PFCs removal would result from the continuous oxidation processes such as ozone and adsorption processes such as activated carbon rather than a single biological treatment.
REVIEW | doi:10.20944/preprints201809.0336.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Adsorption; Emerging contaminants; Biomass; Biochar; Activated carbon
Online: 18 September 2018 (09:06:00 CEST)
This review analyzes the synthesis and characterization of biomass-derived carbons for adsorption of emerging contaminants from water. The study begins with the definition and different types of emerging contaminants more often founded in water streams and the different technologies available for their removal including adsorption. It also describes the biomass sources that could be used for the synthesis of biochars and activated carbons. The characterization of the adsorbents and the different approaches that could be employed for the study of the adsorption processes are also detailed. Finally, the work reviews in detail some studies of the literature focused on the adsorption of emerging contaminants on biochars and activated carbons synthesized from biomass precursors.
ARTICLE | doi:10.20944/preprints201807.0489.v1
Subject: Chemistry, Physical Chemistry Keywords: CO2 adsorption, CH4 adsorption, biomass, activated carbon.
Online: 25 July 2018 (15:29:22 CEST)
The aim of the present study is to provide new insights into the CO2 and CH4 adsorption using a set of biomass-based activated carbons obtained by physical and chemical activation of olive-stones. The adsorption behavior is analyzed by means of pure gas adsorption isotherms up to 3.2 MPa at two temperatures (303.15 and 323.15 K).The influence of the activation method on the adsorption uptake is studied in terms of both textural properties and surface chemistry. For three activated carbons the CO2 adsorption was more important than that of CH4. The chemically activation resulted in higher BET surface area and micropore volume that lead to higher adsorption for both CO2 and CH4. For methane the presence of mesopores seems to facilitate the access of the gas molecules into the micropores while for carbon dioxide, the presence of oxygen groups enhanced the adsorption capacity.
ARTICLE | doi:10.20944/preprints201808.0483.v1
Online: 29 August 2018 (06:16:51 CEST)
We describe electron temperature measurements in the SSX MHD wind tunnel using two different methods. First, we estimate Te along a chord by measuring the ratio of the C_III 97.7 nm to CIV 155 nm line intensities using a vacuum ultraviolet monochrometer. Second, we record a biasing scan to a double Langmuir probe to obtain a local measurement of Te. The aim of these studies is to increase the Taylor state lifetime, primarily by increasing the electron temperature. Also, a model is proposed to predict magnetic lifetime of relaxed states and is found of predict the lifetime satisfactorily. Furthermore, we find that proton cooling can be explained by equilibration with the electrons.
ARTICLE | doi:10.20944/preprints201907.0156.v1
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: molecular spectroscopy; diatomic spectroscopy; Abel transform; plasma spectroscopy; laser-induced breakdown spectroscopy; laser-induced plasma; plasma dynamics
Online: 11 July 2019 (09:30:23 CEST)
Spatially resolved, line-of-sight measurements of aluminum monoxide emission spectra in laser ablation plasma are used with Abel inversion techniques to extract radial plasma temperatures. Contour mapping of the radially deconvolved signal intensity shows a ring of AlO formation near the plasma boundary with the ambient atmosphere. Simulations of the molecular spectra were coupled with the line profile fitting routines. Temperature results are presented with simultaneous inferences from lateral, asymmetric radial, and symmetric radial AlO spectral intensity profiles. This analysis indicates that we measured shockwave phenomena in the radial profiles, including a temperature drop behind the blast wave created during plasma initiation.
ARTICLE | doi:10.20944/preprints202002.0259.v1
Subject: Physical Sciences, Fluids & Plasmas Keywords: non-thermal atmospheric-pressure biocompatible plasma; diffusion; ozone species; plasma sterilizer
Online: 18 February 2020 (06:47:42 CET)
Medical institutions, where several patients are treated and medical workers engaged, are always exposed to secondary viral and bacterial infections. It is critical to prevent infection transmission by indirect as well as direct contact through air or splash. The infections of most diseases can be transmitted through the air. HEPA filters installed in air conditioning equipment are used to prevent infection transmission through air in medical institutions, but air circulation takes a long time in a large space. Virus and bacteria smaller than 0.3 μm cannot be removed by the HEPA filter; hence, those microbes remain alive throughout the air ventilation. A plasma sterilizer has the capability to provide environmental friendly sterilization by employing reactive oxide species and reactive nitrogen species at a low cost. We developed an excellent plasma sterilizer by using a non-thermal atmospheric-pressure biocompatible plasma (NBP). Ozone concentration in plasma sources has been derived by Kuhn et al. . The diffusion coefficients inside (D0) and outside (D1) the plasma sterilizer have been calculated to be 0.0641 m2 s-1 and 0.717 m2 s-1, respectively. To sustain high O3 concentrations over 121 ppm inside the plasma source and low O3 concentrations below 0.05 ppm outside the sterilizer, it is necessary to keep O3 concentrations at the exit of plasma sterilizer below 0.28 ppm. so that diffusion coefficient D1 has been designed to be as large as 11 times of D0.
ARTICLE | doi:10.20944/preprints201809.0070.v1
Subject: Engineering, Other Keywords: Plasma generation, non-thermal Plasma, pulsating DC power, Ozone, cost-improvement
Online: 4 September 2018 (14:56:31 CEST)
The objective of the prototype is to eliminate the polluting contamination of water sources, due to the leak of industrial waste without any kind of treatment, mainly generated by the industries and home sector. In this project, a prototype of water purification by plasma technology has been designed. The prototype will convert contaminated water into the plasma stream and eliminate the pathogens from the water by exposing it to ultraviolet radiation and plasma sterilisation. The polluted water will be accelerated at high speed using a water pump in order to convert it into a liquid-gas mixture for ease plasma generation. This process will be achieved when the electric supply from a source of alternating current (AC) is applied to the water by means of high voltage electrodes. After which, the mixture slows down to return into liquid form and the clean water is obtained. The whole process takes place without significantly raising the temperature also knows as non-thermal plasma. The device also has an automatic flow and pressure control system. Finally, a short feasibility study has been conducted on the water samples collected and report obtained from Chennai Metropolitan Water Supply and Sewage boards are reported. It has been concluded that this new plasma-based water treatment system will be more efficient and cheaper than the current wastewater treatment techniques and can be used in the future as the replacement of current secondary and tertiary treatments of industrial wastewater.
ARTICLE | doi:10.20944/preprints201807.0229.v1
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: laser-plasma interactions; plasma dynamics and flow; hypersonic flows; emission spectra
Online: 13 July 2018 (10:16:46 CEST)
Micro-plasma is generated in ultra-high-pure hydrogen gas filled inside a cell at a pressure of (1.08 ± 0.033) × 105 Pa (810 ± 25 Torr) by using a Q-switched Nd:YAG laser device operated at 1064 nm wavelength and 14 ns pulse duration. Micro-plasma emission spectra of the hydrogen Balmer alpha line, Hα, are recorded with a Czerny-Turner type spectrometer and an intensified charge-coupled device. The spectra are calibrated for wavelength and corrected for detector sensitivity. During the first few tens of nanoseconds after initiating optical breakdown, significantly Stark-broadened and Stark-shifted Hα lines mark the well-above hypersonic outward expansion. The vertical diameters of the spectrally resolved plasma images are measured for time delays of 10 ns to 35 ns to determine expansion speeds of the order of 100 km/s to 10 km/s. For time delays of the order of 0.5 µs to 1 µs, the expansion decreases to the speed of sound of 1.3 km/s in the near ambient temperature and pressure hydrogen gas.
REVIEW | doi:10.20944/preprints202201.0272.v1
Subject: Engineering, Mechanical Engineering Keywords: Thermally Activated Building System; thermal comfort; thermal mass
Online: 19 January 2022 (14:18:14 CET)
In recent years, several alternatives for improving the thermal comfort conditions inside buildings have been proposed. Among these alternatives, Thermally Activated Building Systems (TABS) have become of interest due to the benefits this technology brings to the building sector. The TABS are embedded in different building components and exchange heat with building envelope to improve the indoor air temperature. This review presents relevant results presented in the literature on the thermal behavior of TABS, the different types of TABS configurations, and the main parameters of TABS studied such as pipe separation, fluid inlet temperature, fluid velocity, and volumetric flow rate. The potential of TABS to improve thermal comfort conditions and provide energy savings is also discussed. Further, this study presents the different modes of application.
ARTICLE | doi:10.20944/preprints202110.0186.v1
Subject: Chemistry, Applied Chemistry Keywords: Adsorption; DFT; Starch-based Activated Carbon; Kinetics; Thermodynamics
Online: 12 October 2021 (14:58:07 CEST)
Cadmium (II) contamination in the environment is an emerging problem due to its acute toxicity and mobility, so it is very urgent to remove this species from industrial wastewater before it is discharged into the environment. Thus, a starch-based activated carbon (AC) with a specific surface area of 1600 m2g-1 is used as an adsorbent for the capturing of toxic Cadmium (II) ions from synthetic solution. The sorbent is characterized by BET, SEM, TEM, XRD, FT-IR, TGA, and zeta potential. The maximum uptake (284 mg g-1) of Cadmium (II) ion is obtained at pH 6. The thermodynamics parameters like ∆G, ∆H, ΔS are found to be -17.42 kJmol-1, 6.49 kJ mol-1, and 55.66 Jmol-1K-1 respectively, revealing that the adsorption mechanism is endothermic, spontaneous, and feasible. The experimental data follows the D-R and Langmuir models well. The mass transfer is controlled by pseudo 2nd order kinetics. Furthermore, the density functional theory simulations demonstrate that the activated carbon strongly interacted with the Cd (II) ion through its various active sites. The adsorption energy noted for all interactive sites is highly negative (-0.45 eV to -10.03 eV), which shows that the adsorption process is spontaneous and stable which is in agreement with the experimental thermodynamics analysis.
ARTICLE | doi:10.20944/preprints202107.0292.v2
Subject: Chemistry, Analytical Chemistry Keywords: Activated carbon; adsorption; ciprofloxacin; pollutant; pumpkin seed; thermodynamics
Online: 14 July 2021 (14:12:02 CEST)
Antibiotics are among the most critical environmental pollutant drug groups. One of the methods used to remove this pollution is adsorption. In this study, activated carbon was produced from the pumpkin seed shell and then modified with KOH. This adsorbent obtained was used in the re-moval of ciprofloxacin from aqueous systems. Fourier Transform-Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), elemental, X-ray Photoelectron Spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and Zeta analyzes were used for the characterization of the ad-sorbent. In particular, the surface area was found to be a very remarkable value of 2730 m2/g. The conditions of the adsorption experiments were optimized based on interaction time, adsorbent amount, pH and temperature. Over 99% success has been achieved in removal works carried out under the most optimized conditions. In addition, it was determined that the Langmuir isotherm is the most suitable model for the adsorption interaction.
ARTICLE | doi:10.20944/preprints201710.0159.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: photodegradation; TiO2; ionic liquids; activated carbon; synergistic effect
Online: 24 October 2017 (11:32:13 CEST)
Ionic liquids (ILs) have gained interest among researchers due to its tunable properties that can be used in wide applications. However, toxicity and bio-degradation studies of ILs proved that most of the aromatic ILs, such as imidazolium is highly toxic and non-biodegradable. Several advance oxidation processes (AOPs) have been investigated by researchers to evaluate the efficiency of the systems for the removal of ILs from wastewater. However, the issue on relative high cost and environmental concern has limited the application of these AOPs in industry. In this research, photocatalytic study using hybrid nano-materials was conducted to evaluate the efficiency of this system as an alternative AOP system for removal of ILs from wastewater. The synergistic effect of adsorption-photodegradation was introduced by depositing Fe-TiO2 onto the functionalized activated carbon (AC). Nano-TiO2 was synthesized using micromulsion method before modification with transition metal and deposited onto the oxidized AC. Photodegradation reaction of 1-butyl-3-methylimidazolium chloride [bmim]Cl was investigated under simulated visible light irradiation. It was observed that the overall efficiency of the system was increased with the increasing amount of Fe dopant. Investigation on the extrinsic factors such as solution pH, initial concentration of ILs and photocatalyst dosage showed to significantly affect the overall efficiency of the systems where the optimum condition for the system was observed at pH 10, with initial ILs at 1mM at 1 g/L of photocatalyst. The best performance photocatalyst was 0.2Fe-TiO2/AC.
ARTICLE | doi:10.20944/preprints202203.0209.v1
Subject: Materials Science, General Materials Science Keywords: alkali activation; anions; alkali activated materials; blast furnace slag
Online: 15 March 2022 (11:20:53 CET)
In the study, ground granulated blast furnace slag was activated with a wide variety of sodium salts to compare the effect of their pH and anion size on the hydration progress and compressive strength development of GGBFS pastes. Research was carried out on samples activated with twelve different sodium salts, cured for one year. Changes in their phase composition (XRD), loss on ignition at different temperatures, expansion and microstructure (SEM+EDS) were examined over the entire curing period. Studies have shown that the presence of sodium ions is more important than the pH of the system, as activation took place even in the case of compounds whose solutions are characterized by low pH, such as sodium tartrate or phosphate. The compressive strength of the pastes ranged from approximately 8 to 65 MPa after one year of curing.
ARTICLE | doi:10.20944/preprints202109.0331.v1
Subject: Chemistry, Applied Chemistry Keywords: Adsorption; DFT; Cadmium(II) ion; Activated carbon; Kinetics; Thermodynamics
Online: 20 September 2021 (12:22:22 CEST)
Cadmium(II) contamination in the environment is an emerging problem due to its acute toxicity and mobility, so it is very urgent to remove this species from industrial wastewater before it is discharged into the environment. Thus, a starch-based activated carbon (AC) with a specific surface area of 1600 m2g-1 is used as an adsorbent for the capturing of toxic cadmium(II) ions from synthetic solutions. The sorbent is characterized by BET, SEM, TEM, XRD, FT-IR, TGA, and zeta potential. The maximum uptake (284 mg g-1) of Cadmium(II) ion is obtained at pH 6. The thermodynamic parameters like ∆G, ∆H, ΔS are found to be -17.42 kJmol-1, 6.49 kJ mol-1, and 55.66 Jmol-1K-1 respectively, revealing that the adsorption mechanism is endothermic, spontaneous, and feasible. The experimental data follows the D-R and Langmuir models well. The mass transfer is controlled by pseudo 2nd order kinetics. Furthermore, the density functional theory simulations demonstrate that the activated carbon strongly interacted with the Cd(II) ion through its various active sites. The adsorption energy noted for all interactive sites is highly negative (-0.45 eV to -10.03 eV), which shows that the adsorption process is spontaneous and stable which is in agreement with the experimental thermodynamics analysis.
Subject: Chemistry, Physical Chemistry Keywords: CO2 capture; Activated carbon; Carbon nanomaterials; Adsorption; Surface area.
Online: 8 April 2020 (11:37:06 CEST)
Carbon dioxide (CO2), a major greenhouse gas, capture and separation has recently become a crucial technological solution to reduce atmospheric emissions from fossil fuel burning. Thereafter, many efforts have been put forwarded to reduce the burden on climate change by capturing and separating them especially from larger power plants by the utilization of different technologies. Those technologies have often suffered from high operating cost and huge energy consumption. On right side, physical process such as adsorption is very cost effective process which have been widely used to adsorb different contaminants including CO2. Henceforth, this review covers the overall efficacies of CO2 capture by the utilization of carbon based materials through adsorption technology. Subsequently, we also address the associated challenges and future opportunities of carbon based materials (CBMs). For CO2 capture, it was found that CBMs followed the order of carbon nanomaterials (i.e., graphene, graphene oxides, carbon nanotubes and their composites) < mesoporous -microporous or hierarchical porous carbons < biochar and activated biochar < activated carbons.
REVIEW | doi:10.20944/preprints201811.0441.v1
Subject: Earth Sciences, Environmental Sciences Keywords: biogas; renewable energy; anaerobic digestion; waste activated sludge; disintegration
Online: 19 November 2018 (09:57:56 CET)
Due to rapid urbanization, the quantity of wastewater treatment plants (WWTP) has increased, and with it the amount of waste generated by them. Sustainable management of this waste can lead to the creation of energy-rich biogas through the fermentation process. This review presents recent advances in the anaerobic digestion process resulting in greater biogas production. Disintegration techniques for enhancing waste activated sludge fermentation can be generally partitioned into biological, physical and chemical, each of which are covered in this review. These disintegration techniques were compared mainly in terms of their biogas yield. It was found that ultrasonic and microwave disintegration provides the highest biogas yield (>500%); however, they are also the most energy demanding (>10,000 kJ kg-1 total solids).
ARTICLE | doi:10.20944/preprints201804.0372.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: hemp bast fibre; hydrothermal processing; KOH activation; activated carbon
Online: 28 April 2018 (12:29:14 CEST)
Synthesis of activated carbon from waste biomass is of current interest towards sustainability. The properties of biomass derived activated carbon largely depends on the carbonization process. This study reports preparing extremel high surface area mesoporous activated carbon from hemp bast fibre using hydrothermal processing. Processing in hot water (390-500oC), then activation using KOH and NaOH was investigated at different loading ratios. The described approach was found to enhance the mesoporosity (centered at 3.0 to 4.5 nm) of the hemp derived activated carbon (HAC) from activation (confirmed by BJH pore size distribution and TEM imaging). BET results showed that the product has an extremely high surface area (2425 m2/g) while the surface functional groups (-OH, COOH, C=C/C-C) were confirmed and quantified by XPS and FTIR results. Increasing KOH concentration was found to enhance the surface area with an optimum biochar to KOH ratio of 1:3. The crystallite domain size of HAC was determined using Raman spectroscopy of different wavelengths. The procedure described in this study is an environmentally friendly scalable route for the mass production of activated carbon using hemp fiber.
ARTICLE | doi:10.20944/preprints201611.0125.v1
Subject: Life Sciences, Virology Keywords: Lamin, EBV latency, transformation, epigenetic regulation, activated B cell
Online: 24 November 2016 (17:53:07 CET)
Lamin A, B and C, the nuclear intermediate-filament proteins, play a role in epigenetic regulation. While Lamin B is expressed in all nucleated cells studied, Lamin A/C are transcribed in most somatic cell types except mature B lymphocytes. Since Epstein-Barr virus (EBV), a human gammaherpesvirus, is associated with tumorigenic processes and is known to alter the epigenotype of its host cells, we studied the expression of the LMNA gene and its epigenetic marks in EBV-carrying human lymphoid cell lines. We observed a high lamin A/C mRNA and protein expression in EBV-immortalized lymphoblastoid cell lines (LCLs) and in group III Burkitt lymphoma (BL) lines where hypomethylated first exons were observed with activating histone marks. In most cell lines with low promoter activity a highly methylated first exon could be detected. Our data showed that methylation of the first exon of LMNA was associated with the downregulation of LMNA expression whereas euchromatic histone marks were enriched at active LMNA promoters in EBV-immortalized LCLs. These data suggest a role for viral latency products to activate LMNAp in EBV-infected latency type III B cells in vitro. Expression of lamin A/C may contribute to the establishment of activated B cell phenotype that needs further explorations.
Subject: Engineering, Automotive Engineering Keywords: MASM; new model for membrane activated sludge system; super-fast membrane activated sludge; particle size distribution; modified COD fractionation; captured COD fractions.
Online: 26 April 2021 (13:01:21 CEST)
The structure of existing activated models is inherently deficient in reflecting the major role of the membrane filtration. This study developed and proposed a novel model, MASM, for the membrane activated process. The effective filtration size imposed by the membrane module, entrapping larger size particles was adopted as the basis of the proposed model. The model defined a modified COD fractionation, accounting for the captured COD fractions as additional model components and utilizing related mass balance relationships. It was implemented for testing the fate of soluble hydrolysable COD and system performance of super-fast membrane activated sludge based on real data for the characterization and process kinetics of domestic sewage and denim processing effluents. Model evaluation was carried for parallel systems with gravity settling and membrane filtration operated at a sludge age range of 0.5-2.0 d. Results reflected significantly better performance of super-fast membrane activated sludge system for both wastewaters, underlining that it was crucially important to account for the captured COD fractions to provide an accurate evaluation of system behavior and effluent quality. This should also be identified as the major shortcoming of the ASM models for evaluating and predicting system performance of activated sludge configurations with membrane separation.
ARTICLE | doi:10.20944/preprints202012.0231.v1
Subject: Chemistry, Chemical Engineering Keywords: Plasma, zinc oxide, photocatalysis, nanomaterials.
Online: 9 December 2020 (15:51:59 CET)
In this work, zinc oxide (ZnO) nanoparticles were modified in a circulating fluidized bed through argon and hydrogen (Ar-H) alternative-current (AC) arc plasma, which shows the characteristics of non-equilibrium and equilibrium plasma at the same time. In addition, a circulating fluidized bed with two plasma jets was used for cyclic processing. The catalytic degradation performance on Rhodamine B (Rh B) by Ar-H plasma modified ZnO and pure ZnO was tested in aqueous media to identify the significant role of hydrogen atoms in Rh B degradation mechanism. Meanwhile, the effects of plasma treatment time on the morphology, size and photocatalytic performance of ZnO were also investigated. The results demonstrated that ZnO after 20 minutes-treatment by Ar-H plasma showed Rh B photocatalytic degradation rate is ten times greater than that of pure ZnO, and the reaction follows a first-kinetics for the Rh B degradation process. Furthermore, the photocatalyst cycle experiment curve exhibited that the modified ZnO still displays optimum photocatalytic activity after five cycles of experiment. The improvement of photocatalytic activity and luminescence performance attributes to the significant increase of the surface area, and the introduction of hydrogen atoms on the surface also could enhance the time of carrier existence where the hydrogen atoms act as shallow donors.
REVIEW | doi:10.20944/preprints201907.0108.v1
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: endometriosis; circular; microRNA; diagnosis; plasma
Online: 8 July 2019 (06:10:33 CEST)
Plasma microRNAs are considered to be potential diagnostic biomarkers for endometriosis. Increasing evidence has shown that a huge amount of miRNAs are abnormally expressed in endometriosis plasma and play irreplaceable roles in diagnosis. The aim of the our study was to identify the differential expression of circular miRNA by reviewing the PubMed, ScienceDirect, and Cochrane databases between normal women and women with endometriosis and analyzing the miRNA data downloaded from the GEO database. Because of the differential miRNA expression in this review, we evaluated the diagnostic values of the differentially expressed miRNAs, particularly during the menstrual phases. According to the cut-off criteria with |log 2 FC|>1.0 and P < 0.05, 36 differentially expressed miRNAs were identified, including 13 upregulated miRNAs and 23 downregulated miRNAs. We developed miR-155, miR-574, miR-23a, and miR-520d via a Venn diagram. Functional enrichment analysis considered that the target miRNAs might be involved in various pathways related to endometriosis, including neurotrophin, Hippo, oocyte meiosis, ubiquitin mediated proteolysis, HTLV-Infection, FoxO, and Rap1 signaling pathways. CTNNB1, MYC, and ES R1 of transcription factors were related to the differentially expressed miRNAs. In summary, our study suggested that a four-miRNA could be included as a prognostic marker in endometriosis.
ARTICLE | doi:10.20944/preprints201807.0382.v1
Online: 20 July 2018 (12:49:20 CEST)
While over half of all spinal cord injuries (SCIs) occur in the cervical region, the majority of preclinical studies have focused on models of thoracic injury. However, these two levels are anatomically distinct—with the cervical region possessing a greater vascular supply, grey-white matter ratio and sympathetic outflow relative to the thoracic region. As such, there exists a significant knowledge gap in the secondary pathology at these levels following SCI. In this study, we characterized the systemic plasma markers of inflammation over time (1, 3, 7, 14, 56 days post-SCI) after moderate-severe, clip-compression cervical and thoracic SCI in the rat. Using high-throughput ELISA panels, we observed a clear level-specific difference in plasma levels of VEGF, leptin, IP10, IL18, GCSF, and fractalkine. Overall, cervical SCI had reduced expressions of both pro- and anti-inflammatory proteins relative to thoracic SCI, likely due to sympathetic dysregulation associated with higher level SCIs. However, contrary to the literature, we did not observe level-dependent splenic atrophy with our incomplete SCI model. This is the first study to compare the systemic plasma-level changes following cervical and thoracic SCI using level-matched and time-matched controls. The results of this study provide the first evidence in support of level-targeted intervention and also challenge the phenomenon of high SCI-induced splenic atrophy in incomplete SCI models.
ARTICLE | doi:10.20944/preprints201704.0126.v1
Online: 19 April 2017 (16:04:45 CEST)
A highly-integrated experimental system for plasma decomposition of fuels was built. Experiments were conducted and confirmed that macromolecular chain hydrocarbons were cracked by large-gap dielectric barrier discharge under the excitation of a microsecond-pulse power supply. Alkanes and olefins with a C atom number smaller than 10 as well as hydrogen were found in the cracked products of n-decane (n-C10H22). The combination of preheating and plasma decomposition had strong selectivity for olefins. Under strong discharge conditions, micromolecular olefins were found in the products. Moreover, there was a general tendency that micromolecular olefins gradually accounted for higher percentage of products at higher temperature and discharge frequency.
ARTICLE | doi:10.20944/preprints201704.0019.v1
Online: 4 April 2017 (09:44:42 CEST)
Thin film transistors (TFTs) using In-Ga-Zn Oxide (IGZO) as active layer and the gate insulator was treated with NH3 plasma and N2O plasma, respectively, which is fabricated on flexible PI substrate in this work. The performance of IGZO TFTs with different plasma species and treatment time are investigated and compared. The experiment results show that the plasma species and treatment time play an important role in the threshold voltage, field-effect mobility, Ion/Ioff ratio, sub-threshold swing (SS) and bias stress stability of the devices. The TFT with a 10 seconds NH3 plasma treatment shows the best performance; specifically, threshold voltage of 0.34 V, field-effect mobility of 15.97 cm2/Vs, Ion/Ioff ratio of 6.33×107, and sub-threshold swing of 0.36 V/dec. The proposed flexible IGZO-TFTs in this paper can be used as driving devices in the next-generation flexible displays.
ARTICLE | doi:10.20944/preprints202206.0404.v1
Subject: Materials Science, Other Keywords: activated carbon; lithium-ion batteries; LTO/Sn composite; sol-hydrothermal
Online: 29 June 2022 (10:04:27 CEST)
Li4Ti5O12 (LTO) exhibits zero-strain behavior, exceptional cycle stability, low cost, and high safety. However, it is still low in electronic and ionic conductivity. Incorporating Sn into LTO materials can increase electronic conductivity and specific capacity. However, Sn still experiences volumetric expansion during the charging/discharging process. Adding activated carbon (AC) into the LTO/Sn composite can help improve the expansion resistance and electronic conductivity. In this work, the AC was first synthesized from charcoals through the carbon activation process and mixed with LTO precursors through the sol-hydrothermal method followed by mixing with Sn through the mechanochemical process to produce LTO@AC/Sn composites. The Sn content was fixed at 15 wt.%, while the AC contents were varied at 1 wt.%, 3 wt.%, and 5 wt.%. The AC specific surface area is increased by more than 100% compared to the non-activated one. The best effects of AC on grain morphology and distribution were found in the LTO/Sn contained 3 wt.% of AC, leading to transfer resistance, ohmic resistance, specific capacity, and coulombic efficiency were found to be 48.1 Ω, 8.5 Ω, 138 mAhg-1, and near 100%, respectively. The result suggests that the LTO@AC/Sn could be a favorable anode active material in lithium-ion batteries.
ARTICLE | doi:10.20944/preprints202001.0056.v1
Subject: Chemistry, Applied Chemistry Keywords: peroxymonosulfate; ferric alginate; activated carbon fiber; visible radiation; heterogeneous photocatalysis
Online: 7 January 2020 (10:32:48 CET)
Azo dyes are the most widely used synthetic dyes in the printing and dyeing process. However, the discharge of untreated azo dyes poses potential threat for human health and aqueous ecosystem. Herein, we fabricated a novel heterogenous catalyst - activated carbon fiber-supported ferric alginate (FeAlg-ACF) . Together with peroxymonosulfate (PMS) and visible light, this photocatalytic oxidation system was used to remove an azo dye - azophloxine. The results indicated that the proposed catalytic oxidation system can remove 100% azophloxine within 24 min, while under the same system, the removal rate was only 92 % and 84 % when ferric alginate was replaced with ferric citrate and ferric oxalate respectively, which showed the superiority of activated carbon fiber-supported ferric alginate. The degradation of azophloxine is achieved by the active radicals (SO4•− and •OH) released from PMS and persistent free radicals from activated carbon fiber. After treating for 24 min, the total organic carbon of azophloxine solution (50 μmol/L) decreased from 1.82 mg/L to 79.3 μg/L and the nitrate concentration of ions increased from 0.3 mg/L to 8.6 mg/L. That is, up to 93.5% azophloxine molecules were completely degraded into inorganic compounds. Consequently, potential secondary contamination by intermediate organic products during catalytic degradation was prohibited. The azophloxine removal ratio was kept almost constant after seven cycles, indicating the recyclability and longevity of this system. Furthermore, the azophloxine removal was still promising at high concentrations of Cl-, HCO3-, CO32-. Therefore, our proposed system is potentially effective to remove dye pollutants from seawater. It provides a feasible method for the development of efficient and environmental friendly PMS activation technology combined with FeAlg-ACF, has significant academic and application value.
REVIEW | doi:10.20944/preprints201803.0269.v1
Subject: Biology, Physiology Keywords: TMEM16A, CLCA1, Cl- channels, Ca2+, Ca2+-activated Cl- channels, Epithelium
Online: 30 March 2018 (11:04:55 CEST)
Calcium-activated chloride secretion in epithelial tissues described for many years. However, the molecular identity of the channel responsible for the Ca2+-activated Cl− secretion in epithelial tissues has remained a mystery. More recently, TMEM16A has been identified as a new putative Ca2 -activated Cl- channel (CaCC),. The primary goal of this article will be to review the characterization of TMEM16A, as it relates to the physical structure of the channel, as well as, important residues that confer voltage and Ca2+-sensitivity of the channel. This review will also discuss the role of TMEM16A in epithelial physiology and potential associated-pathophysiology. This will include discussion of developed knockout models that have provided much needed insight on the functional localization of TMEM16A in several epithelial tissues. Finally, this review will examine the implications of the identification of TMEM16A as it pertains to potential novel therapies in several pathologies.
ARTICLE | doi:10.20944/preprints201712.0086.v1
Subject: Materials Science, Biomaterials Keywords: activated carbon; barley husk; corn cob; agave leaves; biomass; thermogravimetry
Online: 14 December 2017 (07:46:00 CET)
Biomass is a promising alternative and renewable energy source that can be transformed into other value-added products such as activated carbon. In this research, barley husk, corn cob and Agave salmiana leaves were characterized to determine their chemical composition and morphology to evaluate their potentiality as precursors of activated carbons. Based on the main composition results obtained, the biomass samples have suitable chemical and physical characteristics to be considered as good precursors of activated carbons, such as carbon contents greater than 40%, ash content less than 10%, moisture content less than 30%, high volatile contents with values from 75 to 80% and a porous and fibrous morphology. The results indicate that the main compositions in the biomass were cellulose and lignin. The cellulose content was more than lignin (15–26%) for the residues selected. Specifically, a-cellulose contents with values from 52% to 79%, β-cellulose contents of 13–44%, γ-cellulose contents less than 11%, and holocellulose contents of 82–83% were determined. The thermal decomposition for the biomass samples proceeded with five stages attributed to the evaporation of some volatile compounds (70–150 ºC), to the degradation of hemicellulose (180–230 ºC), to the cellulose volatilization (250–350 ºC), to the lignin decomposition (380–550 ºC), and to the degradation of complex polymers and inorganic salts, respectively. The stage corresponding to the cellulose decomposition showed rapid mass decreased in the three residues. This results show that the cellulose and lignin content is another important parameter to evaluate the pyrolysis characteristics of a good precursor of activated carbon.
ARTICLE | doi:10.20944/preprints202207.0208.v1
Subject: Life Sciences, Biochemistry Keywords: plasma; biomarker; proteomics; 2DE; proteoform; pattern
Online: 14 July 2022 (10:14:23 CEST)
Cancer is a complex systemic disease that changes the entire proteome. The analysis of this transformation makes it possible to determine tumor markers, that is, the most characteristic biomacromolecules produced by tumor cells. Here, the question of finding ideal tumor markers, which should be sensitive, specific, and reliable, is an acute issue. Unfortunately, none of the tumor markers, even those used in the clinic, has all these characteristics. Despite this, many tumor markers have demonstrated excellent clinical relevance for monitoring the effectiveness of different treatments for cancer patients. The use of markers also aids in the early detection of cancer recurrence and prognosis. Therefore, the situation in this area can be improved in two ways – by attempting to find an ideal single tumor marker or generating panels of different markers. In both cases, proteomics certainly plays a major role. Human plasma is one of the most popular samples as it is commonly collected in the clinic and provides noninvasive, rapid analysis for any type of disease including cancer. Many efforts have been applied in searching for “ideal” tumor markers digging very deep plasma proteome. There is a line of evidence that the most abundant, so-called “classical plasma proteins”, may be used to generate a tumor biomarker profile. To be comprehensive these profiles should have information not only about protein levels but proteoform distribution for each protein. Initially, the profile of these proteins in norm should be generated. Here, we present data about these profiles generated by two-dimensional electrophoresis with the following mass-spectrometry and immunodetection.
ARTICLE | doi:10.20944/preprints202005.0233.v2
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: Supernova; Plasma; Gravitational Lens; Einstein Cross; Hubble Constant; Hubble Tension
Online: 24 May 2022 (13:24:51 CEST)
Simulations based on Supernova (SN) observations predict several galactic SN explosions (SNe) occur every century. Unlike SNes within the Interstellar Medium (ISM) where ambient gas generally absorbs blast waves within a million years, SNes occurring in a rarified environment outside of the (ISM) generate blast waves which remain in a high velocity free expansion phase for more extended periods. The SN blast wave forms an expanding spherical shell and when multiple blast waves intersect, the overlapping region naturally takes the form of a ring, an arc, or an Einstein Cross structure. The analysis shows the high velocity plasma establishes a medium with permeability which drives the index of refraction greater than 1. As a result, when a shock discontinuity forms in the overlapping region, light is reflected from the host galaxy which exposes the intersecting blast wave regions. The expanding shells are shown to induce an achromatic redshift to the reflected light consistent with those measured for gravitational lenses. Further, it is shown that a Hubble equation for a blast wave around the Milky Way Galaxy can be parameterized to align with measured redshifts of extragalactic light fields over a wide range of distances.
ARTICLE | doi:10.20944/preprints202001.0337.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: slag; basicity; hydrogen plasma; smelting reduction; iron oxide; plasma arc; hydrogen utilisation; degree of reduction; hematite
Online: 28 January 2020 (10:33:33 CET)
Replacing carbon by hydrogen is a huge step towards reducing CO2 emissions in the iron- and steel-making industry. The reduction of iron oxides using hydrogen plasma smelting reduction as an alternative to conventional steel-making routes has been studied at Montanuniversitaet Leoben, Austria. The aim of this work was to study the slag formation during the reduction process and the reduction behaviour of iron oxides. Furthermore, the reduction behaviour of iron ore during continuous feeding was assessed. Mixtures of iron ore and calcined lime with a basicity of 0, 0.8, 1.6, 2.3, and 2.9 were melted and reduced by hydrogen. The off-gas composition was measured during the operations to calculate the process parameters. The reduction parameters, namely the degree of reduction, degree of hydrogen utilisation, produced iron, and slag, are presented. The results of the batch-charged experiments showed that at the beginning of the reduction process, the degree of hydrogen utilisation was high, and then, it decreased over the operation time. In contrast, during the continuous-feeding experiment, the degree of hydrogen utilisation could be kept approximately constant. The highest degrees of reduction and hydrogen utilisation were obtained upon the application of a slag with a basicity of 2.3. The experiment showed that upon the continuous feeding of iron ore, the best conditions for the reduction process using hydrogen could be applied.
ARTICLE | doi:10.20944/preprints202011.0226.v1
Subject: Chemistry, Analytical Chemistry Keywords: activated carbon; hydrothermal carbonization (HTC); exergy analysis; thermoeconomic analysis; circular economy.
Online: 6 November 2020 (08:07:04 CET)
An activated carbon manufacturing process using winemaking waste is analyzed and designed at industrial scale. Starting from experimental research, the chemical transformations and thermodynamics during pruning wood conversion are studied as a basis for plant design. In this way, mass and energy balances of hydrothermal carbonization and physical activation are fulfilled and a thermoeconomic methodology is applied to develop an energy-integrated plant. To achieve this target, a network of heat exchangers is allocated to minimize heat consumption and supply hot domestic water, while a cogeneration cycle is designed to provide electricity and satisfy the remaining heat demand. Furthermore, a sensitivity analysis is carried out to determine the influence of the production scale and other operation parameters, such as annual workload, service life, and capital and feedstock costs, on the economic viability of the plant. The energy balance of the plant indicates that the energy integration design manages to provide 48.9% of the overall process energy demand by crossing hot and cold streams and recovering heat from residual flue gas. On the other hand, the exergy cost analysis identifies the combustion of pruning wood used to provide heat demands as the main source of exergy destruction, confirming the suitability of integration to improve the thermodynamic performance. Including activated carbon production, electricity, and hot domestic water, the exergy efficiency of the plant stands at 11.5%.
ARTICLE | doi:10.20944/preprints202007.0162.v1
Subject: Engineering, Other Keywords: Heterotrophic denitrification; Granular activated carbon (GAC); Bacterial Community; 3D-BER system
Online: 9 July 2020 (01:51:11 CEST)
In this study, a three-dimensional bioelectrochemical reactor system (3D-BERs) with granular activated carbon (GAC) epitomizes a novel treatment technology for treating nitrate-polluted water. The conventional denitrification process faces many challenges, including the huge demand for organic carbon, long-term accumulation of intermediate products, and the adaptation period. Results shown that under the optimal conditions of the COD/NO3--N ratio was 1.5, the denitrification efficiency reached 98.62%, when compared to 81.12% at COD/ NO3--N ratio of 3.5, and the initial pH of 7.5 ± 0.5, NO3--N was entirely removed at 2.2 h without accumulation of nitrite. The high initial ratio of NO2--N/NO3--N is mainly to accelerate the denitrification rate by accelerating the reduction of nitrite. Denitrification process followed by zero-order kinetics linear model for at different concentrations of inlet NO3--N, and achieved higher denitrification rate at greater inlet NO3--N concentration. High-throughput sequencing shows that the community structure and relative abundance of bacteria changed significantly, especially at the genes and the phyla level in immobilized GAC particles. Microbial composition enhanced the removal of nitrogen at the inner surface (IS) and bottom surface (BS) of immobilized GAC carriers. Therefore, this system is expected to be a more efficient and useful supplement or a cost-effective alternative compared to the traditional low carbon to nitrogen wastewater treatment system.
ARTICLE | doi:10.20944/preprints201910.0261.v1
Subject: Materials Science, Metallurgy Keywords: particle size distribution; grinding kinetics; slag; alkali activated materials; compressive strength
Online: 22 October 2019 (15:49:42 CEST)
This study aims to model grinding of a Polish slag and evaluate the particle size distributions of the products obtained after different grinding times. Then, selected products were alkali activated in order to investigate the effect of particle size on the compressive strength of the produced alkali activated materials (AAMs). Other parameters affecting alkali activation, i.e. temperature, curing and ageing time were also examined. Among the different mathematical models used to simulate the particle size distribution, Rosin-Rammler (RR) was found to be the most suitable. When piecewise regression analysis was applied to experimental data it was found that the particle size distribution of the slag products exhibits multi fractal character. In addition, grinding of slag exhibits non-first-order behavior and the reduction rate of each size is time dependent. The grinding rate and consequently the grinding efficiency increases when the particle size increases, but drops sharply near zero after prolonged grinding periods. Regarding alkali activation, it is deduced that among the parameters studied, particle size (and the respective specific surface area) of the raw slag product and curing temperature have the most noticeable impact on the compressive strength of the produced AAMs.
ARTICLE | doi:10.20944/preprints201809.0322.v1
Subject: Biology, Other Keywords: p21-activated kinase (PAK); Pancreatic ductal adenocarcinoma (PDA); PF-3758309; gemcitabine
Online: 17 September 2018 (15:28:54 CEST)
Pancreatic ductal adenocarcinoma (PDA) remains the most lethal malignancy due to lack of an effective treatment. P21-activated kinases (PAKs) play key roles in PDA growth, and the PAK inhibitor PF-3758309 synergistically reduced PDA growth with gemcitabine. The aim of this study was to determine the effect of PF-3758309 with multiple chemotherapeutic reagents on a panel of patient-derived PDA cell lines. Cells were treated with PF-3758309 plus or minus gemcitabine, 5-fluorouracil (5-FU) or abraxane, and cell proliferation was determined. Protein expression profiles were measured by Western blot. PDA cells were subcutaneously injected into the flanks of SCID mice which were then treated with PF-3758309, gemcitabine, PF-3758309 plus gemcitabine, or gemcitabine plus abraxane. Tumour growth was measured by volume and weight. PF-3758309 enhanced the inhibitory effects of 5-FU, gemcitabine and abraxane on a panel of patient-derived PDA cells, inhibited HIF-1 protein expression and reduced the protein levels of palladin and -SMA in these cells. The combination of PF-3758309 with gemcitabine maximally inhibited PDA growth in vivo, which was comparable to the combination of gemcitabine with abraxane. PF-3758309 enhanced the suppressive effects of multiple chemotherapeutic reagents on the growth of a panel of patient-derived PDA cell lines. The combination of PF-3758309 with gemcitabine provides a potential treatment option with less toxicity than gemcitabine plus abraxane.
ARTICLE | doi:10.20944/preprints201809.0160.v1
Subject: Materials Science, General Materials Science Keywords: Sound Absorption Coefficient; Noise; Activated Zeolite; Banana Stem Fibre; Acoustical material
Online: 10 September 2018 (09:32:23 CEST)
The unique porous crystal structure of zeolite offers various important utilizations, it is one of the considerations in selecting zeolite at this study as component of composite for restraining noise. It so happens, previous experiments show that banana stem has porous structure, fibrous, high flexibility and can be applied as material for many various products including as component of acoustic material. The combination of both is alleged that it has capability in absorbing noise. This paper presents an investigation on the composite that it was synthesized of Activated Zeolite and Banana Stem Fibre in various weight for determining its sound absorption coefficient alpha (a). Activating natural zeolite was conducted by using 6M HCl in order for enlarging zeolite pores. The sound absorption coefficient was measured in the frequency range between 125 Hz up to 6000 Hz. The results show that the different weight of banana stem fibre as component of the synthesized composite affects the value of alpha and shifts the frequency area.
ARTICLE | doi:10.20944/preprints202009.0397.v1
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: dual frequency comb spectroscopy; mid-infrared absorption and dispersion spectroscopy; electrical discharge plasma; time-resolved plasma kinetics
Online: 17 September 2020 (11:03:42 CEST)
Conventional mechanical Fourier Transform Spectrometers (FTS) are able to simultaneously measure absorption and dispersion spectra of gas-phase samples. However, they usually need very long measurement times to achieve time-resolved spectra with a good spectral and temporal resolution. Here, we present a mid-infrared dual-comb-based FTS in an asymmetric configuration, providing broadband absorption and dispersion spectra with a spectral resolution of 5 GHz, a temporal resolution of 20 μs, and a total measurement time of a few minutes. We used the dual-comb spectrometer to monitor the reaction dynamics of methane and ethane in an electrical plasma discharge. We observed ethane/methane formation as a recombination reaction of hydrocarbon radicals in the discharge in various static and dynamic conditions. The results demonstrate a new analytical approach for measuring fast molecular absorption and dispersion changes and monitoring fast dynamics of chemical reactions, which can be interesting for chemical kinetic research and particularly for the combustion and plasma analysis community.
ARTICLE | doi:10.20944/preprints201904.0261.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: hydrogen plasma; smelting reduction; iron oxide; plasma arc; degree of hydrogen utilization; degree of reduction; hematite; basicity
Online: 23 April 2019 (13:16:39 CEST)
The development of hydrogen plasma smelting reduction as a CO2 emission-free steel-making process is a promising approach. This study presents a concept of the reduction of hematite using hydrogen thermal plasma. A laboratory scale and pilot scale hydrogen plasma smelting reduction (HPSR) process are introduced. To assess the reduction behavior of hematite, a series of experiments has been conducted and the main parameters of the reduction behavior, namely the degree of hydrogen utilization, degree of reduction and the reduction rate are discussed. The thermodynamic aspect of the hematite reduction is considered and the pertinent calculations have been carried out using FactSageTM 7.2. The degree of hydrogen utilization and the degree of reduction were calculated using the off-gas chemical composition. The contribution of carbon, introduced from the graphite electrode, ignition pin and steel crucible, to the reduction reactions was studied. The degree of reduction of hematite, regarding H2O, CO and CO2 as the gaseous reduction products, is determined. It is shown that the degree of hydrogen utilization and the reduction rate were high at the beginning of the experiments, then decreased during the reduction process owing to the diminishing of iron oxide. Conducting experiments with the high basicity of slag B2=2 led to a decrease of the phosphorus concentration in the produced iron.
REVIEW | doi:10.20944/preprints201805.0459.v1
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: white dwarfs; burning in stars; plasma diagnostics; atomic spectra; plasma spectroscopy; laser spectroscopy; laser-induced breakdown spectroscopy
Online: 31 May 2018 (05:13:00 CEST)
This work communicates a review on Balmer series hydrogen beta line measurements and applications for analysis of white dwarf stars. Laser-induced plasma investigations explore electron density and temperature ranges comparable to white dwarf star signatures such as Sirius B, the companion to the brightest star observable from the earth. Spectral line shape characteristics of the hydrogen beta line include width, peak separation, and central dip-shift, thereby providing three indicators for electron density measurements. The hydrogen alpha line shows two primary line-profile parameters for electron density determination, namely, width and shift. Both Boltzmann plot and line-to-continuum ratios yield temperature. The line-shifts recorded with temporally- and spatially- resolved optical emission spectroscopy of hydrogen plasma in laboratory settings can be larger than gravitational redshifts that occur in absorption spectra from radiating white dwarfs. Published astrophysical spectra display significantly diminished Stark or pressure broadening contributions to red-shifted atomic lines. Gravitational redshifts allow one to assess the ratio of mass and radius of these stars, and subsequently, the mass from cooling models.
ARTICLE | doi:10.20944/preprints202010.0291.v1
Subject: Materials Science, Biomaterials Keywords: textile fabric; zeolite; coconut shell activated carbon; NOx; SOx; fine dust particle
Online: 14 October 2020 (09:09:06 CEST)
An effective method for coating textile fabrics with porous materials is proposed, and the removal rates of nitrogen oxides (NOx), sulfur oxides (SOx), and fine dust particles in the coated textile fabrics are evaluated. The textile fabrics made of polyester are used to effectively reduce fine dust particles through static electricity. Zeolite and coconut shell activated carbon are used as porous material to reduce SOx and NOx, respectively. The effects of the epoxy content and dilution solution types on the SOx removal rate of textile fabrics coated with zeolite are evaluated to determine the optimum coating conditions. In addition, the effects of external environmental conditions, such as washing and freeze thawing, on the SOx and NOx removal rates of the textile fabrics coated with porous materials using the optimum coating conditions are examined. The test results show that the SOx removal rate of textile fabrics coated with zeolite decreases with the increase in the epoxy content. The decrease is 2.9 times larger for textile fabrics coated using deionized water than those coated using isopropyl alcohol. After one wash, the SOx removal rate decreases dramatically. However, the decrease is reduced by 16% when the epoxy content ratio is increased by 0.5%. The effects of washing and freeze thawing on the SOx and NOx removal rates of textile fabrics coated using the deionized water diluted with the epoxy content ratio of 2% are minimal. Consequently, to maintain stable SOx and NOx removal rates under external environmental conditions such as washing and freeze thawing, 98% deionized water dilution and 2% epoxy content ratio are required for the optimum coating of textile fabrics with zeolite and coconut shell activated carbon.
ARTICLE | doi:10.20944/preprints201908.0093.v2
Subject: Chemistry, Food Chemistry Keywords: spent coffee grounds; polyphenols; extraction; subcritical fluid; activated carbon; methylene blue; adsorption.
Online: 20 September 2019 (10:23:51 CEST)
A valorization process of spent coffee grounds (SCG) was studied. Thus, a two-stage process, a stage of extraction of the polyphenols and a stage of obtaining activated carbon (AC) by a carbonization process, was performed. The extraction was carried out with a hydro-alcoholic solution in a pressure reactor, modifying time and temperature. To optimize the extraction of polyphenols, a two-level factorial design with three replications at the central values was used. The best results were obtained by performing the extraction at 80 °C during 30 min, using a mixture of EtOH:H2O 1:1 (v/v) as extraction solution. Caffeine and chlorogenic acid were the most abundant compounds in the analyzed extracts, ranging from 0.09 to 4.8 mg∙g-1 and 0.06 to 9.7 mg∙g-1, respectively. The precursor obtained in the extraction stage were transformed into AC. An experimental design was realized in order to analyze the influence of different variables in the AC obtained process (reaction time and amount of potassium hydroxide used). Actived carbons with BET specific surface (SBET) comprised between 1600 m2∙g-1 and 2330 m2∙g-1 had a microporous surface. Under the optimum conditions, the obtained AC presented a maximum adsorption capacity of methylene blue (qm) between 411 mg∙g-1 and 813 mg∙g-1.
ARTICLE | doi:10.20944/preprints201708.0015.v1
Subject: Life Sciences, Molecular Biology Keywords: ischemia-reperfusion injury (IRI), ω3-PUFA, AMP-activated protein kinase (AMPK), autophagy
Online: 4 August 2017 (12:56:08 CEST)
Regulated autophagy is involved in the repair of renal ischemia-reperfusion injury (IRI). ω3-Polyunsaturated fatty acids (ω3-PUFAs) show protective effects against various renal injuries. It was recently reported that ω3-PUFAs regulate autophagy. We assessed whether ω3-PUFAs attenuated IR-induced acute kidney injury (AKI) and evaluated associated mechanisms. C57Bl/6 background fat-1 mice and wild-type mice (wt) were divided into four groups: wt sham (n = 10), fat-1 sham (n = 10), wt IRI (reperfusion 35 min after clamping both the renal artery and vein; n = 15), and fat-1 IRI (n = 15). Kidneys and blood were harvested 24 h after IRI. Renal histological and molecular data were collected. The kidneys of fat-1 mice showed better renal cell survival, renal function, and pathological damage than those of wt mice after IRI. In addition, fat-1 mice showed less oxidative stress and autophagy impairment; greater amounts of LC3, Beclin-1, and Atg7; lower amounts of p62; and higher levels of renal cathepsin D and ATP6E than wt kidneys. They also showed more AMPK activation, which resulted in the inhibition of phosphorylation of the mammalian target of rapamycin (mTOR). Collectively, ω3-PUFAs in fat-1 mice contributed to AMPK mediated autophagy activation, leading to a renoprotective response.
ARTICLE | doi:10.20944/preprints202208.0240.v1
Subject: Physical Sciences, Nuclear & High Energy Physics Keywords: polarized ion beam; polarimetry; laser-plasma acceleration
Online: 12 August 2022 (12:51:46 CEST)
We present a compact polarimeter for 3He ions with special emphasis on the analysis of short-pulsed beams accelerated during laser-plasma interactions. We discuss the specific boundary conditions for the polarimeter, such as the properties of laser-driven ion beams, the selection of the polarization-sensitive reaction in the polarimeter, the representation of the analyzing-power contour map, the choice of the detector material used for particle identification, as well as the production procedure of the required deuterated foil-targets. The assembled polarimeter has been tested using a tandem accelerator delivering unpolarized 3He ion beams, demonstrating good performance in the few-MeV range. The statistical accuracy and the deduced figure-of-merit of the polarimetry are discussed, including the count-rate requirement and the lower limit of accuracy for beam-polarization measurements at a laser-based ion source.
ARTICLE | doi:10.20944/preprints202207.0416.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: biofouling; deposition; hydrophobic; plasma treatment; PTFE; stickiness
Online: 27 July 2022 (08:53:19 CEST)
The spray drying process causes the buildup of an unspecified and unique pattern of wall deposits on the wall. The powder recovery of fruit juice by spray dryer is associated with stickiness problems because of the nature of food which contains low molecular weight sugars and organic acids, which have a low glass transition temperature (Tg). The surface properties of oxygen plasma treated-PTFE substrate were evaluated by using the different parameters of Plasma Enhanced Chemical Vapour Deposition (PECVD) prior to spray drying analysis. In this study, the fabrication method of nearly perfect superhydrophobic surfaces through plasma treatment with oxygen gas was generated and utilized. The plasma-treated PTFE were deposited from a fixed flow rate of oxygen gas with 30 cm3/min by varying the deposition time from 1 to 15 minutes to induce the hydrophobic surface of the PTFE substrate. The characterization techniques used to determine the morphology and chemical bonding of the substrate are field emission scanning electron microscopy (FESEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The hydrophobicity of the glass samples was determined by the water droplet contact angle. Sample prepared at radio frequency (RF) power of 90W for 15 minutes duration of treatment time showed porous and spongy like microstructure which correlates with the best performance of a good contact angle which creates the superhydrophobicity regime (171o). Surface morphology analysis using scanning electron microscopy (SEM) showed changes in its roughness in the surface-treated glass substrate. The success of this method produced a huge potential for solving most of the food processing issues which relate to biofouling (e.g., powder stickiness) that would otherwise struggle to improve high productivity and recovery.
ARTICLE | doi:10.20944/preprints202203.0044.v1
Subject: Physical Sciences, Radiation & Radiography Keywords: energetic material; plasma; detonation; electromagnetism; high temperature
Online: 2 March 2022 (10:39:48 CET)
In the process of deflagration of energetic materials, strong electromagnetic radiation is to be generated, which causes the surrounding electronic equipment to fail to work normally. To solve this problem, it is necessary to clarify the mechanism of electromagnetic radiation generated by energetic materials. The mechanism of plasma changed by the deflagration of energetic materials is an important topic in the aerospace and geophysics fields. The academic community holds two main viewpoints on the mechanism of electromagnetic radiation generated by energetic materials: one is that the solid material is squeezed and deformed during the deflagration of energetic materials, and the charges of different polarities rub in space to form effective electric dipoles, which eventually generate electromagnetic radiation. Another view is that the deflagration of energetic materials causes the temperature of the medium to rise sharply, and bremsstrahlung is formed during the compression and diffusion of the high-temperature wave front, resulting in the generation of electromagnetic radiation. This paper, based on theoretical analysis and experimental data, holds the view that electromagnetic radiation is generated by the high-temperature thermal effect. It studies the relationship between temperature and electromagnetic radiation and obtains quantitative analysis conclusions.
ARTICLE | doi:10.20944/preprints202110.0439.v2
Subject: Materials Science, Polymers & Plastics Keywords: geopolymer; plasma; surface treatment; fly ash; wettability
Online: 1 March 2022 (12:42:26 CET)
This paper deals with investigation of changes in geopolymer wettability with increasing mass fraction of high-carbon fly ash and surface treatment by cold atmospheric plasma (CAP). In this study, multiple samples of geopolymers were prepared, including those with 5% and 10% of high-carbon fly ash from coal-fired power station. Wettability of samples was then measured before and after plasma treatment, both on surface and cut surface. While addition of fly ash only had low effect on the wettability, as in most cases, it only lowered the initial contact angle without speeding up the speed of soaking for compact geopolymer and actually slowed the soaking for foamed geopolymer, plasma treatment had significant impact and made the geopolymer hydrophobic.
ARTICLE | doi:10.20944/preprints202202.0299.v1
Subject: Materials Science, Metallurgy Keywords: aluminum nitride; plasma chemical synthesis; nitride ceramics
Online: 23 February 2022 (15:01:18 CET)
A technology for obtaining nanosized aluminum nitride powder by plasma-chemical synthesis is presented. Nitrogen gas (N2), melamine (C3H6N6) and ammonia (NH3) were used as a source of nitrogen. Aluminum powder of different fractions was used as a source of aluminum. The influence of the nitrogen source, the height of the injector, and the input power of the plasma equipment on the synthesized aluminum nitride powder is shown. The resulting aluminum nitride powder has a size d90=60 nm. The parameters of aluminum nitride synthesis did not in any way affect the granulometric composition of the synthesized powder materials. It was found that, due to the high binding energy, the nitrogen molecule (N2) reacts poorly with aluminum powder particles, as a result a mixture of nitrogen and ammonia gases was used in a ratio of 70/30 (mol.%) for aluminum nitride synthesis.
ARTICLE | doi:10.20944/preprints202106.0583.v1
Online: 23 June 2021 (12:47:11 CEST)
The mechanical engineering requires heat treatment after rough machining to reach the mechanical strength, but the heat treatment can induce workpiece deformation, so that the workpiece cannot be reworked. In this study, the plasma was integrated with a lathe, and the on line heat treatment was performed to achieve the mechanical strength and hardness, so as to reduce the machining process and handling. However, for on line heat treatment, it is important to study the machine and plasma parameters of the lathe and plasma, and the research method is used eventually to optimize the process, reduce the machining cost and machining error. The variable factors in surface on line real-time heat treatment are revolution, feed rate and current, the objective function is the hardness of mechanical properties. In the screening experiment, the interaction of factors was discussed using full factorial experiment. The Central Composite Design was combined with the Lack-of-Fit test for optimization experiment, the R2 coefficient was used to determine whether the regression model is appropriate. The optimum parameters were derived from the contour diagram and response surface diagram. The experimental results show that the significant factors include revolution, feed rate and current, the optimum parameters include revolution 168rpm, feed rate 0.068mm/rev and current 86A. The experimental results of optimum parameters show that the surface hardness is increased from 306HLD to 806HLD, the surface hardening effect is enhanced by 163%, so the on line real-time heat treatment equipment has a best hardening effect.
ARTICLE | doi:10.20944/preprints202005.0250.v8
Subject: Physical Sciences, Acoustics Keywords: Plasma; accelerated expansion; parallel universe; duality; antimatter
Online: 17 December 2020 (11:45:26 CET)
The Planck Legacy recent release revealed a closed and positively curved early universe with a confidence level greater than 99%. In this study, the Friedmann–Lemaîtree–Robertson–Walker (FLRW) metric is enhanced to model early universe plasma, incorporating its reference curvature radius upon the emission of the cosmic microwave background (CMB) and the reference scale factor of the energy flux. The universe evolution from early plasma is modelled utilising quantised spacetime worldlines, where they revealed both positive and negative solutions implying that matter and antimatter in the plasma could be separated by electromagnetic fields and evolved in opposite directions as distinct sides of the universe, corroborating the CMB dipole anisotropy. The model indicates a nascent hyperbolic expansion is followed by a first phase of decelerating expansion during the first 10 Gyr, and then, a second phase of accelerating expansion. The model theoretically resolves the tension in Hubble parameter measurements, with a predicted density at the phase transition of 1.16. Further, it predicts a final time-reversal phase of rapid spatial contraction leading to a Big Crunch, signalling a cyclic universe. Simulations of the quantised spacetime continuum flux through its travel along the predicted worldlines demonstrated the fast-orbital speed of stars resulting from an external momentum exerted on galaxies via the spatial curvature through imaginary time dimension. These findings indicate that early universe plasma could be separated and evolved into distinct sides, collectively and geometrically influencing the universe evolution.
ARTICLE | doi:10.20944/preprints202011.0225.v1
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: Stark-Zeeman effect; Rydberg atom; plasma spectroscopy
Online: 6 November 2020 (08:01:41 CET)
A new method of line shape calculations of hydrogen-like atoms in magnetized plasmas is presented. This algorithm makes it possible to solve two fundamental problems in the broadening theory: the analytical description of the radiation transition array between excited atomic states and account of a thermal ion motion effect on the line shapes formation. The solution to the first problem is based on the semiclassical approach to dipole matrix elements calculations and the usage of the specific symmetry properises of the Coulomb field. The second one is considered in terms of the kinetic treatment of the frequency fluctuation model (FFM). As the result one has a universal description of line shapes under the action of the dynamic of ion’s microfield. The final line shape is obtained by the convolution of the ionic line shape with the Voigt electron-Doppler profile. The method is applicable formally for large values of principle quantum numbers. However, it is demonstrated the efficiency of the results even for well known first members of the hydrogen Balmer series Dalpha and Dbeta. The comparison of obtained results with accurate quantum calculations is presented. The new method may be of interest for investigations of spectral line shapes of hydrogen-like ions presented in different kinds of hot ionized environments with the presence of a magnetic field, including SoL and divertor tokamak plasmas.
ARTICLE | doi:10.20944/preprints202009.0719.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Diabetes mellitus, screening, HbA1c, fasting plasma glucose
Online: 29 September 2020 (15:12:26 CEST)
Background: Diabetes is a common non-communicable disease that is responsible for about 9% of all deaths and 25% reduction in life expectancy and nearly half of the diabetic patients are not aware of their disease. In this regard, diabetes screening to identify un-known diabetic patients is of great importance. Aims: The aims of this study were first to evaluate the performance of two commonly used diabetes screening tests that are currently recommended by the Iranian national screening program for diabetes (NSPD). Methods: The validities of the two diabetes screening tests were measured among 1057 participants older than 30 years. The studied screening tests included Capillary fasting blood glucose (CBG) and glycated hemoglobin (HbA1c). The golden standard for measuring the validity of the tests was venous fasting plasma glucose (VPG). Results: According to the results, the sensitivity of CBG and HbA1c tests were 69.01% and 84.5% and the specificity of the tests were 95.7% and 79.3% respectively. Positive and negative predictive values were 53.84% and 97.72% for CBG and 22.72% and 98.61% for HbA1c respectively. The recommended cut-points for CBG and HbA1c were 116.5 mg/dl and 7.15% respectively. Using these values as the new cut-points, sensitivity and specificity of CBG and HbA1c changed to 80.30% and 89.10%, and 77.50% and 94.20% respectively. Conclusions: Compared to several other countries, the performance of NSPD is relatively higher in Iran. ROC analysis suggested new cut-points for significantly better performance of NSPD.
REVIEW | doi:10.20944/preprints202007.0090.v1
Subject: Life Sciences, Immunology Keywords: COVID-19; Immunotherapy; Immunomodulator; Antibody; Plasma; Immunoglobulins
Online: 5 July 2020 (17:01:31 CEST)
Since the outbreak of SARS CoV-2 infection (Covid-19), healthcare professionals worldwide have been trying to find disease management and control alternatives to encourage immunotherapies. Immunotherapy is an efficient therapeutic option used against comparable viral contaminations such as MERS-CoV and SARS-CoV. The aim of the current study is to assess the existing knowledge associated with SARS-CoV-2 immunotherapy. Information available in published articles and their quality highlights the importance of following strict scientific rules for clinical outcomes. Thus, these studies have shown enough data to confirm that immunomodulation is the main topic investigated in research about Covid-19 therapy. Therefore, it is possible saying that immunotherapy is certainly the appropriate option against this virus.
REVIEW | doi:10.20944/preprints202006.0263.v1
Subject: Life Sciences, Molecular Biology Keywords: biomarker; blood/plasma; cancer; ctDNA; liquid biopsy
Online: 21 June 2020 (11:22:36 CEST)
Circulating tumor DNA (ctDNA) in fluids has gained attention because ctDNA seems to identify tumor-specific abnormalities, which could be used for diagnosis, follow-up of treatment, and prognosis: the so-called liquid biopsy. Liquid biopsy is a minimally invasive approach and presents the sum of ctDNA from primary and secondary tumor sites. It has been possible not only to quantify the amount of ctDNA but also to identify (epi)genetic changes. Specific mutations in genes have been identified in the plasma of patients with several types of cancer, which highlights ctDNA as a possible cancer biomarker. However, achieving detectable concentrations of ctDNA in body fluids is not an easy task. ctDNA fragments present a short half-life, and there are no cut-off values to discriminate high and low ctDNA concentrations. Here, we discuss the use of ctDNA as a cancer biomarker, the main methodologies, the inherent difficulties, and the clinical predictive value of ctDNA.
ARTICLE | doi:10.20944/preprints202005.0406.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Drospirenone 4mg; breastfeeding; plasma concentration; milk concentration
Online: 24 May 2020 (20:26:11 CEST)
Objective: The primary objective of this trial was to assess the transfer of drospirenone to breast milk after daily administration of an oral test preparation containing 4 mg of drospirenone at the steady state. The secondary objective of the trial was to assess the safety of the preparation based on safety clinical and laboratory measurements (at the beginning and at the end of the trial) and reporting of adverse events and/or adverse drug reactions. Patients and Methods: This was an open label, non-comparative single center study. Drospirenone 4mg per day was the first postpartum contraceptive for the study participants who were no longer breastfeeding yet were still lactating. It was administered for 7 (seven) days to achieve steady-state concentration. All participants were volunteers who planned to use oral contraceptives as their family planning method in the future. Results: A total number of 12 volunteers completed the trial according to the protocol and the samples of all the 12 study completers were analyzed. The average concentration-time curve of drospirenone in plasma 24 h after the administration of the last dose (AUC(0-24h)) was 635.33 ng*h/mL and 120 h after the single repeat dose administration (AUC(0-120h) was 1180.57 ng*h/mL, respectively. The average Cmax was 48.64 ng/mL. The average concentration-time curve of drospirenone in milk 24 h after the administration of the last dose (AUC(0-24h)) was 134.35 ng*h/mL and 120 h after the single repeat dose administration (AUC(0-120h) was 227.17 ng*h/mL respectively. The average Cmax was 10.34 ng/mL. Conclusion: On average 18.13% of plasma drospirenone made it to breast milk and the highest concentration of drospirenone in breast milk was 17.55% of that in plasma. The total quantity of drospirenone passing to breast milk is on average 4478 ng during a 24 h period representing 0.11% of the maternal daily dose. Thus, at the recommended doses, no effects on breastfed newborns/infants are anticipated with drospirenone 4 mg.
ARTICLE | doi:10.20944/preprints201812.0326.v1
Online: 28 December 2018 (03:57:18 CET)
The Ti-6Al-4V alloy is widely used in the manufacture of components that should have low density, high corrosion resistance, and fatigue strength. The fatigue strength can be improved by surface modification. The aim of this study was to determine the influence of plasma nitriding on the fatigue behavior of Ti-6Al-4V alloy with a lamellar microstructure (Widmanstätten type). Nitriding was executed at 720 °C for 4 hours in an atmosphere with N2, Ar and H2. Samples microstructure characterization was carried out by X-ray diffraction analysis, optical microscopy and scanning electron microscopy. The average roughness of the specimens was determined, and fatigue tests were executed in a bending-rotating machine with reverse tension cycles (R= -1). X-ray diffraction analysis revealed the matrix phases α and β, and the phases Ɛ-Ti2N and δ-TiN in the nitrided alloy. A nitrogen diffusion layer was formed between the substrate and the titanium nitrides. Plasma nitriding resulted in an increase in low cycle fatigue strength, whereas at high cycles, both conditions exhibit similar behavior. The fracture surface of the fatigue tested specimens clearly revealed the lamellar microstructure. The fracture mechanism appears to be due to cracking at the interface of α and β phases of the lamellar microstructure.
ARTICLE | doi:10.20944/preprints201711.0099.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: renal function; iohexol plasma clearance; swine model
Online: 16 November 2017 (03:11:30 CET)
There is no simple method to measure glomerular filtration rate (GFR) in swine, an established model to study renal disease. We developed a protocol to measure GFR in conscious swine with the plasma clearance of iohexol. We used two groups: testing and validation, of 8 animals each. Ten milliliters of iohexol (6.47 g) were injected by the marginal auricular vein and blood samples (3 ml) were collected from the orbital sinus at different points after injection. GFR was determined considering two models: two-compartments (CL2: all samples) and one-compartment (CL1: the last six samples). In the testing group, CL1 overestimated CL2 by ~30%: CL2=245±93 and CL1=308±123 ml/mn. This error was corrected by a first order polynomial quadratic equation to CL1, which was considered the simplified method: SM=-47.909+(1.176xCL1)–(0.00063968xCL12). SM showed narrow limits of agreement with CL2, and a concordance correlation of 0.97 and a total deviation index of 14.73%. Similar results were obtained for the validation group. This protocol is reliable, reproducible, can be performed in conscious animals, uses a single dose of the marker, and requires a reduced number of samples avoiding urine collection. Finally, it portends a significant improvement in animal-welfare conditions and handling necessities in experimental trials.
ARTICLE | doi:10.20944/preprints202111.0273.v1
Subject: Physical Sciences, General & Theoretical Physics Keywords: General Relativity; Improved Schwarzschild Black hole; Plasma medium; Gauss-Bonnet theorem; Non plasma medium; Hawking radiation; Greybody Factor.
Online: 15 November 2021 (19:36:28 CET)
We explore the deflection angle in the framework of improved Schwarzschild Black hole utilizing the most advance geometrical path adopted by Gibbon-Werner. To investigate deflection angle of the photon ray by weak gravitational lensing for this black hole, we derive the optical curvature and perform the application of Gauss-Bonnet theorem on the optical metric. Moreover, we study the impacts of the plasma medium in context of the weak gravitational lensing in relate to this black hole. Further, we also study the graphical analysis of the deflection angle in both the plasma and non-plasma mediums. Also, we find the rigorous bound base upon the greybody factor for improved Schwarzschild black hole. A while later, we contrast our conclusions about deflection angle with the deflection angles of Schwarzschild black hole within plasma and non-plasma mediums.
ARTICLE | doi:10.20944/preprints202007.0321.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: Collisionless plasma dynamics; Gaseous plasma; Vlasov equation; Maxwell equations; Entropy; Extended Gibbs formula; The Earth's plasmasphere; the magnetosphere.
Online: 15 July 2020 (08:47:59 CEST)
In the upper charged layers of the atmosphere, the plasma is very rarefied. The collisions between its molecules are almost non-existent, and the driving forces behind them are the Lorentz forces resulting from the electric and magnetic fields. For this reason, we are interested in studying the behavior of non-collision plasmas because of its essential applications, such as the movement of satellites in the charged atmosphere. In this paper, the flow problem of collisionless gaseous plasma is examined. For that propose, we solve the unsteady Vlasov-Maxwell system of non-linear partial differential equations analytically. Methods of moments and traveling wave parameters are used to acquire an exact solution. Specific macroscopic properties of collisionless gaseous plasma are calculated along with electrical and magnetic fields. Further, thermodynamic estimation, such as entropy and entropy production, is presented. Those calculations allow us to measure the consistency with the laws of non-equilibrium thermodynamics. Relations between internal energy modification participations are predicted using Gibbs' equation for collisionless plasma. The modification effect of internal energies due to electro-magnetic fields is found to be small compared with the internal energy change due to the effect of entropy. That is because these fields are self-induced by plasma particles due to the sudden movement of the rigid plane plate. The results are accomplished according to the typical argon gaseous plasma model. Three-dimensional diagrams showing the measured variables are drawn to investigate and discuss their behavior. The problem has many commercial applications for the movement of objects in the charged atmosphere.
ARTICLE | doi:10.20944/preprints202112.0076.v1
Subject: Engineering, Other Keywords: oxygen plasma 2; active oxygen species 3; plasma irradiation on seed and leaf 4; growth enhancement 5; gene expression
Online: 6 December 2021 (13:28:01 CET)
Gene expression variations of plant leaf are investigated by irradiating seed and leaf with oxygen or air plasmas. Enhancement of leaf growth is induced by oxygen plasma irradiation on seeds, which is supported by increased gene expression for protein synthesis, oxidative-reduction reactions and decreased gene expression concerning DNA methylation and histone modification. Suppression of leaf growth is observed by the oxygen plasma, which would be owing to increased gene expression concerning heat shock protein and redox reaction, and decreased expression of photosynthesis and glycoprotein. Also, gene expression variation due to air plasma irradiation is almost same as that of oxygen plasma. Active oxygen species are major factors in both oxygen and air plasmas for the variation of gene expressions in plant.
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: plasma diagnostics; molecular spectra; diatomic molecules; plasma spectroscopy; laser spectroscopy; laser-induced breakdown spectroscopy; optical emission spectroscopy; hypersonic expansion
Online: 15 January 2020 (07:12:25 CET)
This article reports new measurements of laser-induced plasma hypersonic expansion measurements of diatomic molecular cyanide (CN). Focused, high-peak power 1064-nm Q-switched radiation of the order of 1 TW/cm2 generates optical breakdown plasma in a cell containing a 1:1 molar gas mixture of N2 and CO2 at a fixed pressure of 1.1 × 105 Pascal and in a 100 ml/min flow of the mixture. Line-of-sight (LOS) analysis of recorded molecular spectra indicate the outgoing shockwave at expansion speeds well in excess of Mach number 5. Spectra of atomic carbon confirm an increased electron density near the shock wave, and equally, molecular CN spectra reveal higher excitation temperature near the shockwave. The results are consistent with corresponding high-speed shadow graphs obtained by visualization with an effective shutter speed of five n anosecond. In addition, LOS analysis and application of integral inversion techniques allow inferences about the spatio-temporal distribution of the plasma.
ARTICLE | doi:10.20944/preprints202201.0395.v1
Subject: Materials Science, Other Keywords: blast furnace granulated slag; silica fly ash; alkali-activated materials; denitrification; material engineering.
Online: 26 January 2022 (12:33:00 CET)
This article deals with the possibility of partial replacement of blast furnace slag with fly ash after denitrification by the Selective Non-Catalytic Reduction (SNCR) method in alkali-activated materials. In the experiment, the basic physical-mechanical properties and durability properties were tested, the hydration reaction was monitored in a calorimeter and infrared spectroscopy was performed. Results were compared between mixtures prepared with fly ash without denitrification and also with reference mixture based only on alkali-activated blast furnace slag. The basic result is the finding, that hybrid alkali-systems with fly ash after denitrification show similar trends as hybrid alkali-systems with fly ash without denitrification. The significant effect of fly ash is manifested especially in terms of resistance to freeze-thaw. The reactions in the calorimeter show a slower development of reactions with increasing replacement of slag by fly ash. In the case of testing resistance to leaching in demineralised water, a decrease of flexural strength was found, which corresponds to the conclusions of strength testing, that long-term deposition of bodies in water causes deterioration of mechanical properties.
ARTICLE | doi:10.20944/preprints202110.0374.v1
Subject: Materials Science, Biomaterials Keywords: Oxygen reduction reaction; Nanoporous activated carbon; Cobalt-nitrogen-doped carbon; Nonprecious metal catalyst
Online: 26 October 2021 (11:34:57 CEST)
Compared with precious metal catalysts, non-platinum catalysts have the advantages of low cost and high performance. Among them, the activated carbon (AC) with a large specific surface area (SSA) can be used as a carrier or as a carbon source of nonprecious metal/carbon system catalyst at the same time. Therefore, this paper uses cheap pine peel bio-based materials to prepare large surface area activated carbon and then compound with cobalt phthalocyanine (CoPc) to obtain a high-performance cobalt/nitrogen/carbon catalyst. The merits include AC@CoPc composite catalysts are prepared by precisely controlling the composite proportion of AC and CoPc, the atomically dispersed Co nanoparticles form and synergistically with N promote the exposure of CoNx active sites, and the Eonset of the catalyst treated with a composite proportion of AC and CoPc of 1 to 2 at 800 °C (AC@CoPc-800-1-2) is 1.01 V, which is higher than Pt/C (20 wt%) catalyst. Apart from this, the stability is 87.8% in 0.1 M KOH after 20000 s testing in compared with other AC@CoPc series catalysts and Pt/C (20 wt%) catalyst. Considering from the performance and price of the catalyst in practical application, these composite catalysts combine biomass carbon materials with phthalocyanine series, which will be widely used in the area of nonprecious metal catalysts.
ARTICLE | doi:10.20944/preprints202010.0627.v1
Subject: Chemistry, Analytical Chemistry Keywords: activated carbon; winemaking waste; wastewater; Cr(VI) removal; adsorption process; Cr(VI) reduction
Online: 30 October 2020 (08:28:29 CET)
A winemaking waste was used as a precursor of activated carbon used in hazardous Cr(VI) removal from solutions. The preparation process consisted of a hydrothermal process, and a chemical activation, of the resulting product, with KOH. The adsorption results showed that the adsorption of Cr(VI) on the obtained activated carbon is strongly dependent on the stirring speed applied to the carbon/solution mixture, pH of the solution, and temperature. The equilibrium isotherm was well fitted to the Langmuir type-II equation, whereas the kinetic can be described by the pseudo-second-order kinetic model. Thermodynamic studies revealed that Cr(VI) adsorption was an exothermic and spontaneous process. Finally, desorption experiments showed that Cr(VI) was effectively desorbed using hydrazine sulfate solutions, and at the same time, the element was reduced to the less hazardous Cr(III) oxidation state.
ARTICLE | doi:10.20944/preprints201911.0244.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: activated inflammatory macrophages; quercetin; pro-/anti-inflammatory cytokine genes; STAT3 protein phosphorylation; TLR2
Online: 20 November 2019 (16:04:42 CET)
Our previous studies demonstrated that quercetin (Q) could be ingested and metabolized by macrophages and exerted prophylactic immuno-stimulatory activity and therapeutic anti-inflammatory effects on lipopolysaccharide (LPS)-treated macrophages ex vivo. To further clarify its possible anti-inflammatory mechanism, Q was selected to treat mouse peritoneal macrophages that obtained from female BALB/c mice exposed to LPS i.p. for 12 h. Relative gene expression of pro-/anti-inflammatory (TNF-α/IL-10) cytokines and components of inflammation-related intracellular signaling pathways (TLR2, TLR4, NF-κB, JAK2 and STAT3) was analyzed using two-step reverse transcription (RT) and real-time quantitative polymerase chain reaction (qPCR). STAT3 protein phosphorylation was determined using an in-cell ELISA method. As a result, Q and its metabolite quercetin-3-O-β-D-glucuronide (Q3G) decreased TNF-α gene expression amounts and ratios of pro-/anti-inflammatory (TNF-α/IL-10) cytokine gene expressions, but increased IL-10 gene expression amounts in activated inflammatory macrophages, supporting a substantial anti-inflammatory potential of Q and Q3G treatments. However, Q3G had lower effects than those of Q. Importantly, Q inhibited TLR2 gene expression and phosphorylation of STAT3 protein in the inflamed cells. Our results are the first report to suggest that Q inhibits LPS-induced inflammation ex vivo through suppressing TLR2 gene expression and STAT3 protein phosphorylation in activated inflammatory macrophages. Q has potential to further apply for treating inflammation-associated diseases.
ARTICLE | doi:10.20944/preprints201805.0114.v2
Subject: Chemistry, Applied Chemistry Keywords: biomass; bio-char; activation; activated carbon; thermal treatment; physical activation; porosity; specific surface areas
Online: 25 June 2018 (05:08:15 CEST)
Activated carbons can be produced from biomass in a thermal process either in a direct carbonization-activation process or by first carbonizing the biomass and later on activating the biochars into activated carbons. The properties of the ACs are dependent on the type of process used for production. In this study, the properties of activated carbons produced in a one-stage and a two-stage process are considered. Activated carbons were produced by physical activation of two types of starting materials, bio chars produced from spruce and birch chips in a commercial carbonization plant and from the corresponding raw chips. The activated carbons produced were characterized regarding specific surfaces, pore volumes and pore size distributions. The un-activated bio chars had some degree of surface area 190 and 140 m2g-1 for spruce and birch and pore volumes of 0.067 and 0.092 cm3g-1. According to the results obtained, two slightly different types of activated carbons are produced depending if a one-stage or a two-stage carbonization and activation process is used. The ACs produced in the one-stage process had higher specific surface areas compared to the ones produced in a two-stage process (761-940 m2g-1 vs. 540-650 m2g-1) . In addition, total pore volumes were higher in one-stage process but development of micropores is greater compared to two-stage process. There was no significant difference in total carbon content between one-stage and two-stage process.
ARTICLE | doi:10.20944/preprints201702.0009.v1
Subject: Chemistry, Other Keywords: N2-Arylcarbonyl/sulfonylanthranilamides; Prothrombin time; Activated partial thromboplastin time; Thrombin; Factor Xa; U46619
Online: 3 February 2017 (18:55:26 CET)
Thrombin (factor IIa) and factor Xa (FXa) are key enzymes at the junction of the intrinsic and extrinsic coagulation pathways and are the most attractive pharmacological targets for the development of novel anticoagulants. Twenty non-amidino N2-thiophencarbonyl- and N2-tosyl anthranilamides 1-20 and six amidino N2-thiophencarbonyl- and N2-tosylanthranilamides 21-26 were synthesized and evaluated prothrombin time (PT) and activated partial thromboplastin time (aPTT) using human plasma at concentration 30 μg/mL in vitro. From these results, compounds 5, 9, and 21-23 were selected to study the further antithrombotic activity. The anticoagulant properties of 5, 9, and 21-23 significantly exhibited a concentration-dependent prolongation of in vitro PT and aPTT, in vivo bleeding time, and ex vivo clotting time. These compounds concentration-dependently inhibited the activities of thrombin and FXa and inhibited the generation of thrombin and FXa in human endothelial cells. In addition, data showed that 5, 9, and 21-23 significantly inhibited thrombin catalyzed fibrin polymerization and mouse platelet aggregation and inhibited platelet aggregation induced U46619 in vitro and ex vivo. N-(3'-Amidinophenyl)-2-((thiophen-2''-yl)carbonyl amino)benzamide (21) was most active.
ARTICLE | doi:10.20944/preprints201610.0027.v1
Subject: Biology, Physiology Keywords: Liver X receptor (LXR); Peroxisome proliferator-activated receptor (PPARγ); Adipose expansion; Insulin resistance
Online: 10 October 2016 (07:56:30 CEST)
Liver X receptors (LXR) are deemed as potential drug targets for atherosclerosis, whereas a role in adipose tissue expansion and its relation to insulin sensitivity remains unclear. To assess the metabolic effects of LXR activation, C57BL/6 mice on a high-fat diet (HFD) were treated with the dual LXRα/β agonist T0901317 (30 mg/kg per day) for 3 weeks. Differentiated 3T3-L1 was used for analysing the effect of T0901317 on glucose uptake.T0901317 reduced fat mass, accompanied by a massive fatty liver and lower adipokine levels in circulation of HFD mice. Increased adipocyte apoptosis and macrophage infiltration were found in epididymal fat of T0901317-treated HFD mice. In addition, T0901317 treatment promoted basal lipolysis, but blunted the anti-lipolytic action of insulin. Furthermore, LXR activation antagonized PPARγ target genes in epididymal fat and PPARγ-PPRE binding activity in 3T3-L1 adipocytes. Although the glucose tolerance was comparable to that in vehicle-treated HFD mice, the insulin tolerance was significantly decreased in T0901317-treated HFD mice, indicating decreased insulin sensitivity by T0901317 administration, and which was further supported by impaired insulin signalling found in epididymal fat and decreased insulin-induced glucose uptake in 3T3-L1 by T0901317administration. These findings reveal that LXR activation impairs adipose expansion which contributes to decreased insulin sensitivity.
ARTICLE | doi:10.20944/preprints202209.0449.v1
Subject: Engineering, Energy & Fuel Technology Keywords: pulsed power plasma discharge; electromagnetic; COMSOL; numerical simulation
Online: 29 September 2022 (03:32:36 CEST)
The scope of this work was part of our previous research on Pulsed Power Plasma Stimulation Technique. Electromagnetic fields generated during a pulsed power plasma discharge were simulated using a finite element method in the COMSOL RF module. The field distributions were calculated during and after the pulse. The current paper takes advantage of prior work measuring and modeling the current distribution in the plasma arc. Agreement with laboratory experimental measurements provides support for extension of the model to reservoir scale. The validated model was used to quantify the signal attenuation level in different medium environment.
ARTICLE | doi:10.20944/preprints202110.0404.v1
Subject: Medicine & Pharmacology, Other Keywords: pathogen reduction; blood safety; platelet transfusion; INTERCEPT; plasma
Online: 27 October 2021 (12:27:33 CEST)
(1) Background: We reviewed the logistics of the implementation of pathogen inactivation (PI) using the INTERCEPT Blood System™ for platelets and the experience with routine use and clinical outcomes in the patient population at the Sírio-Libanês Hospital of São Paulo, Brazil. (2) Methods: Platelet concentrate (PC), including pathogen reduced (PR-PC) production, inventory management, discard rates, blood utilization, and clinical outcomes were analyzed over the 40 months before and after PI implementation. Age distribution and wastage rates were compared over the 10 months before and after approval for PR-PC to be stored for up to 7 days. (3) Results: A 100% PR-PC inventory was achieved by increasing double apheresis collections and production of double doses using pools of two single apheresis units. Discard rates decreased from 6% to 3% after PI implementation and further decreased to 1.2% after 7-day storage extension for PR-PCs. The blood utilization remained stable, with no increase in component utilization. A significant decrease in adverse transfusion events was observed after the PI implementation. (4) Conclusion: Our experience demonstrates the feasibility for Brazilian blood centers to achieve a 100% PR-PC inventory. All patients at our hospital received PR-PC and showed no increase in blood component utilization and decreased rates of adverse transfusion reactions.
ARTICLE | doi:10.20944/preprints202007.0059.v1
Subject: Life Sciences, Biophysics Keywords: plasma membrane; rafts; microemulsion; phase-separation; domain size
Online: 5 July 2020 (10:09:41 CEST)
It is widely, but not universally, believed that the lipids of the plasma membrane are not uniformly distributed, but that "rafts'' of sphingolipids and cholesterol float in a "sea'' of unsaturated lipids. The physical origin of such heterogeneities is often attributed to a phase coexistence between the two different domains. We argue that this explanation is untenable for several reasons. Further we note that the results of recent experiments are inconsistent with this picture. However they are quite consistent with an alternate explanation, namely that the plasma membrane is an emulsion of the two kinds of regions. To show this, we briefly review a simplified version of this theory and its phase diagram. We also explicate the dependence of the predicted domain size on four physical parameters. Among them are the spontaneous curvature of the membrane and its bending modulus and surface tension. Taking values of the latter two from experiment, we obtain domain sizes for several different cell types that vary from 58 to 88 nm.
ARTICLE | doi:10.20944/preprints201905.0371.v1
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: non-extensive entropic principle; plasma turbulence; quasi equilibrium
Online: 31 May 2019 (06:12:02 CEST)
The Boltzmann-Gibbs (BG) entropy has been used in a wide variety of problems for more than a century. It is well known that BG entropy is extensive, but for certain systems such as those dictated by long-range interactions, the entropy must be non-extensive. Tsallis entropy possesses non-extensive characteristics, which is parametrized by a variable q (q = 1 being the classic BG limit), but unless q is determined from microscopic dynamics, the model remains but a phenomenological tool. To this date very few examples have emerged in which q can be computed from first principles. This paper shows that the space plasma environment, which is governed by long-range collective electromagnetic interaction, represents a perfect example for which the q parameter can be computed from micro-physics. By taking the electron velocity distribution function measured in the heliospheric environment into account, and considering them to be in quasi equilibrium state with electrostatic turbulence known as the quasi-thermal noise, it is shown that the value corresponding to q = 9/13 = 0.6923 may be deduced. This prediction is verified against observation made by spacecraft, and it is shown to be in excellent agreement.
ARTICLE | doi:10.20944/preprints201905.0241.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: gold; surface of electrodes; ozone; plasma; raids layer
Online: 20 May 2019 (10:31:34 CEST)
During the long-term operation of the plasma reactor, decreases in the plasma concentration were noticed despite the constant maintenance of all parameters. One of the factors is the decrease of the nitrogen content on the surface of the electrode, in order to eliminate it, the supply voltage has been increased to 11 kV. The next decisive factor in the decrease of plasma concentration is the oxidation of the electrode surface, therefore two electrodes were used: first one with solid gold and the other one copper covered with galvanized gold with a thickness of 10 μm. During the experiment, a large decrease in plasma concentration was observed when the electrode coated by gold was used. High-energy electrons have knocked out the gold atoms from the electrode, as a result of which the gold evaporated and the raids layers formed. After a month of working of the electrodes, metallographic researches were carried out, the results of which are described in this publication.
COMMUNICATION | doi:10.20944/preprints201905.0163.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: plasma spray; in-flight particles; molten status; YSZ
Online: 13 May 2019 (14:18:40 CEST)
In order to achieve better knowledge of the thermal barrier coatings (TBCs) by supersonic atmospheric plasma spraying (SAPS) process, an experimental study was carried out to elaborate physicochemical properties of particles in-flight during the SAPS process. One type of commercially available agglomerated and sintered yttria-stabilized-zirconia (YSZ) powders were injected into the SAPS plasma jet and collected by shock chilling method. The YSZ particles in-flight physicochemical properties of the melting state, morphology, microstructure, particle size distribution, element composition changes and phase transformation during the SAPS process have been systematically analyzed. The melting state, morphology and microstructure of the collected particles were determined by scanning electron microscopy (SEM). The particle size distribution was measured by a laser particle size analyzer (LPSA). Element compositions were quantitatively analysed by an electron probe X-ray microanalyzer (EPMA). Additionally, the X-ray diffraction (XRD) method was used to analyse the phase transformation. The results showed that the original YSZ powders injected into the SAPS plasma jet were quickly heated and melted from the outer layer companied with breakup and collision-coalescence. The outer layer of the collected particles containing roughly hexagonal shaped grains exhibited a surface texture with high sphericity and the inside was dense with hollow structure. The median particle size was decreased from 45.65 μm to 42.04 μm. Besides, phase transformation took place and the content of zirconium (Zr) and yttrium (Y) element was decreased with the evaporation of ZrO2 and Y2O3.
ARTICLE | doi:10.20944/preprints201811.0482.v1
Subject: Materials Science, Biomaterials Keywords: polycaprolactone; oxygen plasma; Wharton’s Jelly mesenchymal stem cells
Online: 20 November 2018 (05:26:00 CET)
Cell-based therapies and tissue engineering applications require biocompatible substrates that support and regulate the growth, survival, and differentiation of specific cell types. Extensive research efforts in regenerative medicine are devoted to the development of tunable biomaterials which support various cell types including stem cells. In this research, the non-cytotoxic biopolymer polycaprolactone (PCL) was fabricated into 2D and 3D scaffolds with or without the low-pressure oxygen plasma treatment to enhance hydrophilicity. Cellular responses and biocompatibility were evaluated using a human Wharton’s jelly mesenchymal stem cell line (BCP-K1). The 2D PCL scaffolds enhanced initial cell attachment compared to the 3Ds indicated by a higher expression of focal adhesion kinase (FAK). Whilst, the 3D scaffolds promoted cell proliferation and migration as evidenced by higher cyclin A expression and filopodial protrusion, respectively. The 3D scaffolds potentially protected the cell entering to apoptosis/necrosis program and induced cell differentiation, evaluated by gene expression. Both 2D and 3D PCL appeared to have stronger effects on cell behavior than a control substrate (polystyrene). In summarize, the different configuration and surface properties of PCL scaffolds provide various options for modulation of stem cell behaviors, including attachment, proliferation, survival, and differentiation, when combined with specific growth factors and culture conditions.
ARTICLE | doi:10.20944/preprints201805.0446.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: plasma-TIG; coupled arc; arc profile; pressure distribution
Online: 30 May 2018 (09:39:07 CEST)
In this article, a novel hybrid welding process called plasma-TIG coupled arc welding was proposed to improve the efficiency and quality of welding by utilizing the full advantage of plasma and TIG welding processes. The two arcs of plasma and TIG were pulled into each other into one coupled arc under the effect of Lorentz force and plasma flow force during welding experiments. The arc behavior of coupled arc was studied by means of it’s arc profile, arc pressure and arc force conditions. The coupled arc pressure distribution measurements were performed. The effects of welding conditions on coupled arc pressure were evaluated and the maximum coupled arc pressure was improved compared with single-plasma arc and single-TIG arc. It was found that the maximum arc pressure was mainly determined by plasma arc current and plasma gas flow. According to the results, the proposed coupled arc welding process have both advantages of plasma arc and TIG method, and it has a broad application prospect.
ARTICLE | doi:10.20944/preprints201704.0080.v1
Online: 14 April 2017 (04:41:05 CEST)
Metabolomic analysis of biological fluids and tissues has become an increasingly routine tool in the biological toolbox. However, challenges remain to be overcome, including developing strategies to maximise coverage of the metabolome without requiring large sample volumes. Here we describe a multimodal strategy that combines data using both LC-MS and GC-MS from a unique vial with a sample of plasma (20µl) or a sample of brain tissue (3mg). Using a split phase extraction the non-aqueous phase was analyzed by reversed phase (RP) LC-MS, whilst the aqueous phase was analyzed using hydrophilic liquid interaction chromatography (HILIC)LC-MS, with both phases also analysed using GC-MS after derivatization of the extract. Analytical performance was assessed in 7 rat cerebellum samples and a pilot study of 40 plasma samples (20 vs. 20: AD vs. healthy controls). The method, which uses four hours of instrument time, measured 20,707 metabolite features in brain samples and 17,266 in plasma samples, from those 44.1% features displayed CV’s below 15% and 75.2% below 30%. The method has potential to resolve subtle biological differences and to correlate metabolite composition directly to clinical outcomes including MMSE, age and ADCS-ADL. This method can acquire in the order of 20K metabolic features when low volumes are available.
ARTICLE | doi:10.20944/preprints202011.0652.v1
Subject: Physical Sciences, Acoustics Keywords: laser–plasma interactions; plasma dynamics and flow; hypersonic flows; optical emission spectroscopy; hydrogen; cyanide; Abel inversion; astrophysics; white dwarf stars
Online: 25 November 2020 (16:23:06 CET)
This work communicates the connection of measured shadowgraphs from optically induced air breakdown with emission spectroscopy in selected gas mixtures. Laser-induced optical breakdown is generated using 850 mJ and 170 mJ, 6-ns pulses at a wavelength of 1064 nm, the shadowgraphs are recorded using time-delayed 5-ns pulses at a wavelength of 532 nm and a digital camera, and emission spectra are recorded for typically a dozen of discrete time-delays from optical breakdown by employing an intensified charge-coupled device. The symmetry of the breakdown event can be viewed as close-to spherical symmetry for time-delays of several 100 ns. Spectroscopic analysis explores well-above hypersonic expansion dynamics using primarily the diatomic molecule cyanide and atomic hydrogen emission spectroscopy. Analysis of the air breakdown and selected gas breakdown events permits the use of Abel inversion for inference of the expanding species distribution. Typically, species are prevalent at higher density near the hypersonically expanding shockwave, measured by tracing cyanide and a specific carbon atomic line. Overall, recorded air breakdown shadowgraphs are indicative of laser-plasma expansion in selected gas mixtures, and optical spectroscopy delivers analytical insight into plasma expansion phenomena.
ARTICLE | doi:10.20944/preprints201803.0037.v1
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: Stark broadening; van der Waals broadening; line shapes; helium plasma; corona discharge; plasma diagnostics; code comparison; neutral broadening; pressure broadening
Online: 7 March 2018 (13:36:47 CET)
Passive plasma spectroscopy is a well-established non-intrusive diagnostic technique. Depending on the emitter and its environment which determine the dominant interactions and effects governing emission line shapes, passive spectroscopy allows the determination of electron densities, emitter and perturber temperatures as well as other quantities like abundances. However, using spectroscopy needs appropriate line shape codes retaining all the physical effects governing the emission line profiles. This requires for line shape code developers to continuously correct or improve them to increase their accuracy when applied for diagnostics. This is exactly the aim expected from code-code and code-data comparisons. In this context, the He I 492 nm emitted in a helium corona discharge at room temperature represents an ideal case since its profile results from several broadening mechanisms: Stark, Doppler, resonance and van der Waals. The importance of each broadening mechanism depends on the plasma parameters. Here the profiles of the He I 492 nm in a helium plasma computed by various codes are compared for a selected set of plasma parameters. In addition, preliminary results related to plasma parameter determination using experimental spectra from a helium corona discharge at low pressure 1- 2 bars, are presented.
ARTICLE | doi:10.20944/preprints201803.0040.v1
Subject: Physical Sciences, Atomic & Molecular Physics Keywords: stark broadening; van der waals broadening; line shapes; helium plasma; corona discharge; plasma diagnostics; code comparison; neutral broadening; pressure broadening
Online: 6 March 2018 (03:51:17 CET)
Many spectroscopic diagnostics are routinely used as a technique to infer the plasma parameters from line emission spectra but their accuracy depends on the numerical model or code used for the fitting process. However, the validation of a line shape code requires some steps : comparison of the line shape code with other similar codes for some academic (simple) cases and then more complex ones, comparison of the fitting parameters obtained from the best fit of the experimental spectra with those obtained with other diagnostic techniques and/or comparison of the fitting parameters obtained by different codes to fit the same experimental data. Here we compare the profiles of the hydrogen Balmer β line in a helium plasma computed by six codes for a selected set of plasma parameters and we report on the plasma parameters inferred by each of them from the fitting to a number of experimental spectra measured in a helium corona discharge where the pressure was in the range 1- 5 bar.
ARTICLE | doi:10.20944/preprints202207.0390.v1
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: general relativity; gravitational lensing; wormhole-like static aether solution; Gauss-Bonnet theorem; plasma and non-plasma mediums; dark matter; modified gravity
Online: 26 July 2022 (06:12:06 CEST)
In this paper, we study the deflection angle for wormhole-like static aether solution by using Gibbons and Werner technique in non-plasma, plasma and dark matter mediums. For this purpose, we use optical spacetime geometry to calculate the Gaussian optical curvature, then implement the Gauss-Bonnet theorem in weak field limits. Moreover, we compute the deflection angle by using a technique known as Keeton and Petters technique. Furthermore, we analyze the graphical behaviour of the bending angle ψ with respect to the impact parameter b, mass m as integration constant and parameter q in non-plasma and plasma mediums. We examine that deflection angle is exponentially increasing as direct with charge. Also, we observe that for small values of b, ψ increases and for large values of b the angle deceases. We also considered an analysis to the shadow cast of the wormhole relative to an observer at various locations. Comparing it the the Schwarzschild shadow, shadow cast is possible for wormhole as r<2m. At r>2m, the Schwarzschild is larger. As r → ∞, we have seen that the behavior of the shadow, as well as the weak deflection angle, approaches that of the Schwarzschild black hole. Overall, the effect of plasma tends to decrease the value of the observables due to the wormhole geometry.
ARTICLE | doi:10.20944/preprints201804.0069.v1
Subject: Engineering, Energy & Fuel Technology Keywords: non-thermal plasma; wood gasification; charcoal gasification; water steam gasification; plasma stability; optical temperature measurement; carbon conversion; reaction kinetics; Arrhenius diagram
Online: 5 April 2018 (11:13:38 CEST)
Compared to conventional allothermal gasification of solid fuels (e.g. biomass, charcoal, lignite etc.), plasma-assisted gasification offers an efficient method to apply energy into the gasification process to increase the flexibility of operation conditions and to increase the reaction kinetics. In particular, non-thermal plasmas (NTP) are promising, in which thermal equilibrium is not reached and electrons have substantially higher mean energy than gas molecules. Thus it is generally assumed that in NTP the supplied energy is utilized more efficiently for generating free radicals initiating gasification reactions than thermal plasma processes. In order to investigate this hypothesis, we compared purely thermal to non-thermal plasma assisted gasification of biomass in steam in a drop tube reactor at atmospheric pressure. The NTP was provided by means of gliding arcs between two electrodes aligned in the inlet steam flow. Electric power of about 1 kW was supplied using a high voltage generator operating at frequencies between 70 and 150 kHz and voltage amplitudes up to 10 kV. A laser-assisted optical method (Raman spectroscopy) was applied for measuring the gas temperature both in the conventionally heated steam and flow-down of the visible plasma filaments of the gliding arcs. Reaction yields and rates were evaluated using these measured gas temperatures. The first experimental results have shown that the non-thermal plasma not only promotes the carbon conversion of the fuel particles, but also accelerates the reaction kinetics. The carbon conversion is increased by nearly 10% using wood powder as the fuel. With charcoal powder more than 3% are converted into syngas.
COMMUNICATION | doi:10.20944/preprints202106.0394.v1
Subject: Materials Science, General Materials Science Keywords: Cement By-Pass Dust; Blast Furnace Granulated Slag; Silica Fly Ash; Alkali-Activated Materials.
Online: 15 June 2021 (10:59:34 CEST)
Alkali-activated materials are alternative building binders, where secondary raw materials are processed. Possibility to use landfilled waste materials in their preparation, increases their potential application in construction practice, and therefore they are subject to extensive research, especially in recent years. This paper briefly summarizes interesting results of an experiment aimed at verifying the possibility of applying cement by-pass dust (CBPD) in the preparation of alkali-activated materials. The research work was focused on the possibilities of using these wastes for the preparation of small elements of garden architecture. The paper briefly evaluates in particular the results of X-ray diffraction, which were subjected to three types of binder pastes differing in the amount of used activator. In the experiment, a mixture of blast furnace granulated slag, fly ash and cement by-pass dust was alkali activated with sodium metasilicate.
ARTICLE | doi:10.20944/preprints202011.0580.v2
Subject: Engineering, Construction Keywords: geopolymer; laterite; alkali-activated; alumino-silicates; I-optimal; response surface methodology; optimization; mine waste.
Online: 17 December 2020 (11:43:45 CET)
Geopolymer cement has been popularly studied nowadays compared to ordinary Portland cement because it demonstrated superior environmental advantages due to its lower carbon emissions and waste material utilization. This paper focuses on the formulation of geopolymer cement from nickel-laterite mine waste (NMW) and coal fly ash (CFA) as geopolymer precursors, and sodium hydroxide (SH) and sodium silicate (SS) as alkali activators. Different mix formulations of raw materials are synthesized to produce a geopolymer based from an I-optimal design and obtained different compressive strengths. A mixed formulation of 50% NMW and 50% CFA, SH-to-SS ratio of 0.5, and an activator-to-precursor ratio of 0.429 yielded the highest 28-day unconfined compressive strength (UCS) of 22.10 ± 5.40 MPa. Furthermore, using an optimized formulation of 50.12% NMW, SH-to-SS ratio of 0.516, and an activator-to-precursor ratio of 0.428, a UCS value of 36.30 ± 3.60 MPa was obtained. The result implies that the synthesized geopolymer material can be potentially used for concrete structures and pavers, pedestrian pavers, light traffic pavers, and plain concrete.
REVIEW | doi:10.20944/preprints201809.0360.v1
Subject: Medicine & Pharmacology, Other Keywords: p-21 activated kinase; pioglitazone, metformin, type 2 diabetes mellitus, cancer, chemoprevention, and inflammation.
Online: 19 September 2018 (00:50:05 CEST)
Hypothesis: Anti-diabetic drugs modulate p-21 activated kinase (PAK) signaling Introduction: Type 2 diabetes mellitus (T2DM) is a chronic inflammatory disease associated with increased cancer risk. PAK signaling is implicated in cellular homeostasis when regulated, and cancer when unrestrained. Recent reports provided a role for PAK signaling in glucose homeostasis, but the role of PAKs in the pathogenesis of T2DM is unknown. Here we performed a mini-meta analysis to explore if anti-diabetic drugs modify PAK signaling pathways, and provide insight regarding modulation of these pathways to potentially reduce diabetes-associated cancer risk. Methods: PAK interacting partners in T2DM were identified using online STRING database. Correlation studies were performed via systematic literature review to understand the effect of anti-diabetic drugs on PAK signaling. Mini meta analysis correlated multiple clinical studies and revealed the overall clinical response rate and percentage of adverse events in piogliazone (n=53) and metformin (n=91) treated patients with PAK-associated diseases. Results: A total of 30 PAK interacting partners were identified (10: reduced beta-cell mass; 10: beta-cell dysfunction; 10: obesity-insulin resistance) which were highly associated with Wnt, and G-protein signaling. Anti-diabetic drug metformin activated signaling pathways upstream; whereas pioglitazone inhibited pathways downstream of PAK. Overall clinical response upon pioglitazone treatment was 53%. 79% of pioglitazone and 75% of metformin treated patients had adverse events. Pioglitazone reduced molecular-PAK biomarkers of proliferation (Ki67 and CyclinD1), and metformin had the opposite effect. Conclusions: PAK signaling in T2DM likely involves Wnt and G-protein signaling which may be altered by anti-diabetic drugs metformin and pioglitazone. Apart from the therapeutic limitations of adverse events, pioglitazone may be promising in chemoprevention, however long-term multi-centered studies, which initiate pioglitazone treatment early will be required to fully assess the full potential of these drugs.
REVIEW | doi:10.20944/preprints201808.0403.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: p-21 activated kinase; pioglitazone, metformin, type 2 diabetes mellitus, cancer, chemoprevention, and inflammation.
Online: 23 August 2018 (05:10:55 CEST)
Hypothesis: Anti-diabetic drugs modulate p-21 activated kinase (PAK) signaling Introduction: Type 2 diabetes mellitus (T2DM) is a chronic inflammatory disease associated with increased cancer risk. PAK signaling is implicated in cellular homeostasis when regulated, and cancer when unrestrained. Recent reports provided a role for PAK signaling in glucose homeostasis, but the role of PAKs in the pathogenesis of T2DM is unknown. Here we explored whether PAK signaling should be targeted via chemoprevention to reduce diabetes-associated cancer risk. Methods: PAK interacting partners in T2DM were identified using online STRING database. Systematic literature review provided the effect of anti-diabetic drugs on PAK signaling. Review of clinical studies revealed the overall clinical response rate and percentage of adverse events in piogliazone (n=53) and metformin (n=91) treated patients with PAK-dependent diseases. Results: A total of 30 PAK interacting partners were identified (10: reduced beta-cell mass; 10: beta-cell dysfunction; 10: obesity-insulin resistance) which were highly associated with Wnt, and G-protein signaling. Anti-diabetic drug metformin activated signaling pathways upstream; whereas pioglitazone inhibited pathways downstream of PAK. Overall clinical response upon pioglitazone treatment was 53%. 79% of pioglitazone and 75% of metformin treated patients had adverse events. Pioglitazone reduced molecular-PAK biomarkers of proliferation (Ki67 and CyclinD1), and metformin had the opposite effect. Conclusions: PAK signaling in T2DM involves Wnt and G-protein signaling which is altered by anti-diabetic drugs metformin and pioglitazone. Apart from the therapeutic limitations of adverse events, pioglitazone is promising in chemoprevention, however long-term multi-centered studies, which initiate pioglitazone treatment early will be required to fully assess the full potential of these drugs.
ARTICLE | doi:10.20944/preprints202203.0038.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: polyimide bonding; plasma activation; hydrophilic; hybrid bonding; 3D integration
Online: 2 March 2022 (07:47:17 CET)
Polymer adhesives have emerged as a promising dielectric passivation layer in hybrid bonding for 3D integration while they raise misalignment problems during curing. In this work, the synergistic effect of oxygen plasma surface activation and wetting is utilized to achieve bonding between completed cured polyimides. The optimized process achieves a void-less bonding with a maximum shear strength of 35.3 MPa at a low temperature of 250 °C in merely 2 min, significantly shortening the bonding period and decreasing thermal stress. It is found that the plasma activation generated hydrophilic groups on the polyimide surface, and the wetting process further introduced more -OH groups and water molecular on the activated polyimide surface. The synergistic process of plasma activation and wetting facilitate bridging polyimide interfaces to achieve bonding, providing an alternative path for adhesive bonding in 3D integration.
ARTICLE | doi:10.20944/preprints202201.0105.v1
Subject: Life Sciences, Other Keywords: rabbit; biostimulation; reproduction; urine; seminal plasma; chemocommunication; olfaction; pheromones
Online: 10 January 2022 (12:07:54 CET)
Biostimulation is an animal management practice that helps improve reproductive parameters by modulating animal sensory systems. Chemical signals, mostly known as pheromones, have a great potential in this regard. This study was conducted to determine the influence of short-term female rabbit exposure to different conditions, mainly pheromone-mediated, on reproductive parameters of inseminated does. Groups of 60 females/each were exposed to 1) female urine, 2) male urine, 3) seminal plasma and 4) female-female interaction, just before artificial insemination, and compared to isolated females controls (female-female separated). The following reproductive parameters were analyzed for each group: receptivity (vulvar color), fertility (calving rate), prolificacy and number of born alive and dead kits ⁄ litter. Our results showed that the biostimulation methods employed in this experiment did not significantly improve any of the analyzed parameters. However, female doe exposure to urine, especially to male urine, slightly increased fertility levels when compared to the rest of the experimental conditions. Female-female interaction before artificial insemination, which is a common practice in rabbit farms, did not have any effect, which suggests its removal to avoid unnecessary animal management and time cost. On the other hand, fertility ranges were lower for animals with pale vulvar color whereas no differences were noticed among the other three colours which measure receptivity (pink, red, purple), thus suggesting that these three colours could be grouped together. Additionally, equine chorionic gonadotropin injection could be replaced with various biostimulation methods, therefore reducing or replacing current hormonal treatments, and contributing to animal welfare and to a natural image of animal production.
ARTICLE | doi:10.20944/preprints202111.0532.v1
Subject: Engineering, Other Keywords: Fe-based amorphous coating; AT13; Plasma spraying; Corrosion resistance
Online: 29 November 2021 (12:32:17 CET)
In the present study, the corrosion resistance of amorphous coating and composite coatings in 3.5 wt.% NaCl, 0.5 M H2SO4 and 10 wt.% NaOH solution were studied. The composite coatings exhibit superior corrosion resistance. When the content of AT13 （Al2O3–13 wt.% TiO2）was 15 wt.%, the composite coating has the lowest corrosion current density (1.75×10-6 A cm-2), which is 5.14×10-5 A cm-2 for Fe-based metallic glassy coating, and the highest corrosion potential (-411 mV), which is -580 mV for Fe-based metallic glassy coating. The breakdown potential of the passivation film in 3.5 wt.% NaCl solution was much higher than that of 316L.The long-time immersion corrosion tests carried out on different coatings showed that the corrosion protection effect of coating was enhanced with the increase of the amount of AT13 added.
ARTICLE | doi:10.20944/preprints202103.0289.v1
Subject: Chemistry, Analytical Chemistry Keywords: sphingolipidome; ceramides; high resolution mass spectrometry; whole blood; plasma
Online: 10 March 2021 (16:06:08 CET)
Plasma and serum are the most widely used blood-derived biofluids for metabolomics and lipidomics assays, but the isolation of these products from blood may introduce additional bias as indicated by the fact that many analytes that are present at high concentrations in blood cells cannot be measured and evaluated in those samples. Of particular concern, variable hemolysis during the pre-processing of blood products could compromise accurate and reproducible quantification. Compared with plasma or serum, whole blood may be a better alternative due to simplicity of processing. In this study, we provide a comprehensive method for quantification of the whole blood sphingolipidome and the concentrations were compared with those from plasma. Combining a single-phase extraction method with liquid-chromatography high resolution mass spectrometry (R=120, 000), assisted by alkaline hydrolysis, we were able to identify and simultaneously quantify more than 150 sphingolipids. Furthermore, most of sphingolipids remained stable after a freeze/thaw cycle. Whole blood contained a higher concentration of most sphingolipids than corresponding plasma. Moreover, individual variations in the levels of sphingolipids were lower for whole blood than plasma. These findings demonstrate that whole blood could be a better alternative to plasma, and potentially guide the evaluation of sphinglipidome for biomarker discovery.