In Ecuador, particularly in the El Oro province, gold mining has been historically hampered by arsenic contamination in the ores. This research addresses the persistent issue of arsenic in gold-bearing ores from Miraflores Mine in Cerro Azul, Atahualpa Canton, and the challenges it presents to mining operations. The study's purpose is to evaluate the effectiveness of an alkaline leaching process for arsenic removal. The ore underwent thorough characterisation, employing advanced techniques like fire assay and atomic absorption. Once the ore's nature was discerned, an arsenic extraction experiment using a leaching solution was conducted. The implemented process achieved an arsenic removal efficiency of 90.54%. This enhanced ore quality facilitates efficient metallurgical applications and, more notably, reduces the environmental footprint by diminishing the need for harmful reagents like sodium cyanide. However, a significant implication of this method is the added cost due to the need for heat during the leaching test, amounting to an approximate $30 per ton increase. The alkaline leaching process emerges as a promising solution for arsenic challenges in El Oro’s mining sector. While the findings are encouraging, further expansive tests are recommended to validate the results and underscore the urgency for sustainable and hazard-conscious mining practices.

Carbonaceous material (CM) is common in meta-sediments and is generally interpreted to be intimately associated with gold mineralization. For the Bumo deposit in Hainan Province, South China, CM is mainly hosted by greenschist facies- to amphibolite-facies metamophic rocks of the Paleo- to Mesoproterozoic Baoban Group and by auriferous veins and is used as an important gold prospecting indicator. However, the genesis of CM and the relationship with gold mineralization are still not clear. Field work and thin section observation indicates that two types of CM occur, i.e., layered and veinlet. Layered CM, up to meters thick, prevails in the deposit. More importantly, Au-bearing sulfides are commonly distributed along the boundary between the quartz veins and layered CM. In contrast, veinlet CM, co-precipitated with gold and sulfides, has the thickness of micro- to centi- meters, and these thin veins occur in quartz veins and hydrothermally altered rocks. Scanning Electron Microscope (SEM) analysis indicates that layered CM has a stringy shape and laminate structure, while veinlet CM occurs as isometric particles. Raman carbonaceous material geothermometer indicates that layered CM with high maturity is formed at elevated temperatures of 400 – 550°C, consistent with X-ray diffraction (XRD) analysis. In contrast, veinlet CM with low maturity is formed at 200 – 350°C, generally consistent with gold mineralization. In addition, layered CM has δ13C values ranging from -30 to -20%, demonstrating a biogenic origin. Consequently, it is interpreted that layered CM is formed by a pre-ore metamorphic event during Caledonian, and its reducing nature promotes gold precipitation via destabilization of aqueous Au bisulfide complexes or facilitating sulfidation. Veinlet CM is hydrothermal origin, and its precipitation modified the chemical conditions of ore fluids, leading to the destabilization of Au complexes and thus favorable for mineralization.

The quantitative and qualitative assessment of gold grains from samples of glacial till is a well-established method for exploring gold deposits hidden under glaciated cover. This method, widely used by the industry and which produced numerous successes in locating gold deposits in glaciated terrain, is still based on artisanal gravity separation techniques and visual identification. However, being artisanal, it is limited by inconsistent recoveries and the difficulty to visually identify the predominantly occurring small gold grains. These limitations hinder its capability to deceipher subtle or complex signal. To improve detection limits through recovery of small gold grains, a new approach has recently been introduced in the industry (commercially referred as “ARTGold” procedure) using an optimized miniature sluice box coupled with an automated scanning electron microscopy routine. The capabilities of this improved method are highlighted by comparing till surveys conducted around the Borden gold deposit (Ontario, Canada) using the conventional and improved methods at both local and regional scales. Relative to the conventional approach, the improved method recovered almost one order of magnitude more gold grains from samples (regional and down-ice mineralization), dominantly in small size fractions. Increasing the counts in low-abundance regional samples enables better discrimination between background signals and significant dispersions. The method offers an alternative to improve characterization of gold dispersal in glaciated terrain and the related gold deposit footprints.

Rotor blade bearings enable the rotor blades to pivot about their longitudinal axis and thus control the power output and reduce the loads acting on the wind turbine. Over a design period of 20 years, rolling bearings are exposed to frequent oscillating movements with amplitude ratios of x/2b>1, especially due to new control concepts such as Individual Pitch Control, which can lead to wear and a reduction in service life. The objective of the paper is to identify the dominant wear mechanisms and their consequences for the operation of oscillating bearings. Oscillating experiments with increasing number of cycles on angular contact ball bearings of two different sizes (type 7208 and 7220), show that the damage initiation starts with adhesive and corrosive wear mechanisms, which result in a sharp increase of the torque as well as the wear volume on the bearing raceway. As the number of cycles increases, an abrasive mechanism occurs, resulting in a lower slope of the wear curve and a smoothing of the resulting wear depressions. The wear and torque curves are evaluated and classified using an energy-wear approach according to Fouvry.

Different types of gold nanoparticles have been synthesized that great potential in medical applications such as medical imaging, bio-analytical sensing and photothermal therapy. However, their stability, polydispersity and biocompatibility are major issues of concern. For example, the synthesis of gold nanorods, obtained through the elongated micelle process, produce them with a high positive surface charge that is cytotoxic. While gold nanoshells are unstable and within a few weeks they decompose due to Ostwald ripening. In this work, we report the self-assembly of the capsid protein of cowpea chlorotic mottle virus (CCMV) around spherical gold nanoparticles, gold nanorods and gold nanoshells to form virus-like particles (VLPs). All gold nanoparticles were synthesized or treated to give them a negative surface charge, so they can interact with the positive N-terminus of the capsid protein leading to the formation of the VLPs. To induce the protein self-assembly around the negative gold nanoparticles, we use different pH and ionic strength conditions that were determined from the capsid protein phase diagram. The encapsidation with the viral capsid protein confers them better biocompatibility, stability, monodispersity and a new biological substrate on which one can introduce specific ligands towards particular cells, broadening the possibilities of medical application.

The solvent extraction of gold(III) by undiluted 2-ethylhexanol or dissolved in toluene from HCl solution has been investigated. The numerical analysis of gold distribution data suggests the formation of HAuCl4·L and HAuCl4·2L (L= 2-ethylhexanol) species in the organic phase with formation constants K11= 38 and K12= 309, respectively. The results derived from gold(III) distribution have been implemented in a solid-supported liquid membrane system. The influence of several variables on gold transport was considered: feed and receiving phases stirring speeds, HCl and gold concentrations in the feed phase and carrier concentration in the membrane phase as well as the presence of base metals (Fe,Cu,Ni) and PGMs in the feed phase. Also, diffusional resistances to mass transfer are estimated. Gold is recovered as zero valent nanoparticles.

To increase the power density of the electromechanical drive train of wind turbines, journal bearings can be used as planetary gear bearings instead of rolling bearings. This technological change presents new challenges. For example, wind turbine drive systems are subject to dynamic and low-speed operating conditions which can lead to an accelerated abrasive wear of the journal bearings. In addition, oil supply failure or peak loads due to wind gusts and grid and power converter faults could potentially result in catastrophic failure due to adhesive wear in a very short time. Such operating characteristics are, therefore, critical regarding the journal bearing wear lifetime and must be considered in the design. The successful implementation of journal bearings in wind turbines depends on a reliable estimation of adhesive and abrasive wear. In this paper, five different models for the wear calculation of journal bearings are evaluated regarding their suitability of wear calculation of planetary gear bearings in wind turbines. For this purpose, the following evaluation criteria were defined: parameter uncertainty, parametrization effort, in particular number of parameters, parameterization method and load case dependency of parameters and calculation effort. In order to be able to evaluate the wear models, the wear models are numerically implemented and the wear of a test journal bearing is exemplarily calculated under load conditions, which are comparable to load conditions in a wind turbine. Relevant influences from the wind turbine system such as lubricant, material and manufacturing dependent surface influences like roughness and hardness are considered. The wear models are evaluated with respect to their fulfillment of the defined criteria. The resulting evaluation allows the selection of a wear model that can be used to calculate the wear of planetary gear journal bearings in wind turbines, considering the available input variables.

Mechanical power and motion are often transmitted by the gear-rotor-bearing system. When there are fitting clearances between the housing and outer ring in bearings, complex vibration responses will be generated, which makes the operating status difficult to identify. Therefore, for analyzing dynamic responses, a dynamic model of gear-rotor-bearing systems with bearing fitting clearances is proposed. In the model, the bearing system with fitting clearances and gear pair system are combined, and the coupling relationship is determined by the gyroscopic mo-tion of the shaft. The friction force and collision force caused by fitting clearances are also con-sidered, which are simulated by the Coulomb friction model and Hertz theory. The result shows that the meshing stiffness will also be excited by the bearing displacement. When there are fit-ting clearances on the bearing, the amplitude modulation of the bearing outer raceway to the system time-domain response is intensified, and the multiple harmonic frequency of bearings and gear pairs are generated on the spectrum, as well as defect frequencies of gear pairs. As the fitting clearance is increased, the higher multiple harmonic responses will be caused. Although the response amplitude of the gearbox is increased by raising the input speed, multiple harmon-ic responses are suppressed, which makes the system mainly vibrate at the fundamental fre-quency. Then, the dynamic model and the vibration analysis are experimentally verified.

An integrated two-stage metallurgical technology has been developed for processing concentrates from the Olimpiadinskoe deposit with high antimony and arsenic content. The parameters of the alkaline sulphide leaching process of the initial concentrate of the Olimpiadinskoe deposit, providing maximum extraction of antimony in solution at 99% level have been recommended. The L:S ratio = 4,5:1; the concentration of sodium sulphide - 61 g/L; the concentration of sodium-hydroxide – 6,5 g/L; the duration – 3 hours; the temperature – 50 °C. A synergistic effect of alkaline sulphide leach cakes co-processing by sulphuric and nitric acids has been determined. Pre-treatment allows to reduce the composition of nitric acid by converting the carbonates into gypsum and increases the extraction of arsenic by 15 % at the following nitric leaching. Laboratory research of nitric acid leaching of decarbonized cake allowed to set the basic parameters for maximum iron and arsenic extraction in solution (92 and 98 %): the L:S ratio =9:1; the concentration of nitric acid – 6 mol/L; the time – 90 min. The full polynomial equations for iron and arsenic extraction from decarbonised cake have been derived. The model is relevant since the value the determination coefficients for iron and arsenic R2 were 96,7 and 93,2 %. The high value of gold recovery from the cake of two-stage alkaline sulphide and nitric acid leach cake at 95 % has been established. The maximum value of arsenic deposition from the nitrate leach solution in the form of the insoluble deposition As2S3 99,9 %. A basic technological flowsheet diagram for flotation gold-antimony processing for the Olimpiadinskoe deposit has been developed; it includes two redistributions: production of metallic antimony and gold extraction from the nitric leach cake.

We examined PT parameters, geochemical peculiarities, and fluid sources of the Ulug-Sair ore occurrence attributable to class of intrusion-related gold deposits and according to ore mineral assemblages corresponding to Au-Bi type with wide Bi minerals (AgBiTe, Bi2Te2Se, Cu3,07BiS3, Bi), tellurides (Au and Ag), Se-tellurides (Ag and Bi), and selenides (Au, Ag, and Hg). We identified that ‘pre-gold’ quartz-tourmaline veins were deposited using an aqueous Mg-Na-K-chloride fluid with a salinity of 8–10 wt % NaCl eq. At 325–370 °C; host breasts were formed due to a CO2-water fluid containing CH4 and N2, with a salinity of 0,18–6,1 wt % NaCl eq. at least 200–400 °C. Gold-bearing mineral assemblages were formed at P ~ 0,75–1,0 kbar (~ 2,3–3 km) due to CO2-water chloride (Na-K±Fe, Mg) fluid with CH4, Na2SO4, and Na2B2O5, and salinities 1,7–12,5 wt % NaCl eq. during the decreasing temperatures from 360 up to 115 °C (gold-sulfide-quartz veins – 360–130 °С, and gold-telluride-sulfide-quartz veins – 330–115 °C) and variations fO2, fS2, fSe2, and fTe2. The isotopic composition of δ34SH2S fluid (-0,7…+2,5 ‰) indicates the juvenile or magmatic origin of fluid and ore elements. The δ34OH2O fluid indicates that, at an early substage, the formation of ore occurrence involved a fluid of magmatic or metamorphic origin (+7,3…+11,4 ‰), and, in the later substage, it mixed with meteoric waters (-2,3…+9,1 ‰).

JIS SUJ2 is most widely used in bearing steels. The advantages are good hardenability, excellent fatigue, wear resistance and comprehensive mechanical properties. For wear resistance and fatigue resistance of the steel are getting more and more attention, the residual stress state and its distribution on the surface of the heat affect zone are critical factors affecting the fatigue life and wear resistance of the parts. In this study, using the SUJ2 as the material to talk about the surface residual stress and retained austenite distribution. Doing the quenching and tempering treatment to obtain different microstructures, using the induction method to re-quench the case region. After the heat treatment, measuring the residual stress and retained austenite volume on the surface by X-ray diffraction, observing the microstructure and comparing the hardness. The results show that the microstructure after heat treatment contains unsolidified carbides, tempered martensite and retained austenite. The residual stress on the surface is the tensile state. In the re-hardened area after induction quenching, the residual stress is all compressive, and the values are more than -800 MPa. In conclusion, in the same output power condition can be observed that the microstructure of the specimens before induction hardening has a significant impact on the effective case depth. The surface residual stress has changed from a tensile to a compressive state. In the re-hardened area, the maximum of the residual compressive stress increased with the austenitized temperature increase.

Efficiency improvement is the new challenge in all fields of design. In this scenario the reduction of power losses is becoming more and more a main concern also in the design of power transmissions. Appropriate models to predict power losses are therefore from the earliest stages of the design phase. The aim of the project is to carry on lubrication simulations of several variants of a cylindrical-roller-bearing to understand the lubricant distribution and the related churning power losses. Several strategies to reduce the computational effort have been used. Among them the sectorial symmetry and three innovative meshing strategies (purely analytical with and without interfaces and analytical/subtractive) that have been implemented in the OpenFOAM® environment. The results of the different approaches were compared among them and with experimental observations showing good agreement and reasonable savings in terms of computational effort.

Existing research indicates that mineralization of Carlin-type gold deposit is related to geological structures, but current studies mostly focus on the qualitative association, and lack quantitative analysis of the relationship between mineralization and structural features, which limits the potential for predictive mineral exploration. In this study, the Nibao Carlin-type gold deposit was selected as the research area to conduct three-dimensional geological modeling, spatial analysis, and three-dimensional prospectivity modeling. Spatial analysis revealed that the majority of gold ore bodies are situated near the main fault, with gold mineralization primarily occurring within a spatial range of approximately -80 meters to 20 meters from the main fault plane. This spatial distribution predominantly aligns in a SW-NE direction. Spatial characteristic extraction of fault slope indicators suggests that the slope angles are conducive to the migration and accumulation of ore-forming hydrothermal fluids, with ore body metal content rapidly increasing within an angle range of approximately 20° to 60°. The shape analysis of the mainfault indicates that the principal spaces of mineralization enrichment are within -10m to 20m of the fault plane undulations, where gold resources are concentrated in a relatively flat area. However, the degree of mineralization is more pronounced in the protruding sections than in the depressed areas. The areas with significant dip changes in faults display higher variations in orebody attitudes, with mineralization noticeably weaker in areas where the fault steepness changes markedly. Ore-bearing units exhibit significantly higher grades within the -17° to 3° interval of fault steepness transition. This interval also sees a rapid accumulation of gold resources. The Nibao gold mine's mineralization is derived from deep, ore-bearing hydrothermal fluids ascending along major fractures, precipitating, and accumulating in favorable ore-hosting spaces (faults, anticline cores) and lithological combinations (sedimentary tuffs, tuffs). Three deep potential gold targets were identified, highlighting the deep western edge of the F1 fault and the deep southeast-trending lower plate as prospective areas for future exploration. This study underscores the effectiveness of 3D prospective modeling as an indispensable tool for elucidating the spatial distribution of fault-controlled Carlin-type gold deposits and their tectonic determinants.

A proposed low-temperature forging method aims to enhance stainless steel bearings by creating a martensitic subsurface layer, significantly boosting bearing fatigue life due to increased surface hardness. This technique induces beneficial residual stresses, particularly in axial bearings, streamlining their construction and improving machine elements. Challenges persist, especially with radial bearings, but simplicity in axial bearing forging promotes compact, resource-efficient facility construction. Future research will focus on applying this technique to axial bearing washers, potentially replicating success in other bearing components. Despite the energy ex-penditure for cooling during forging, the substantial increase in bearing fatigue life offsets this, enhancing overall longevity and reliability of critical machine components. Integration of this forging technique into bearing fabrication appears seamless, offering a promising trade-off be-tween energy use and enhanced performance.

The surface plasmon resonance of gold nanoparticles causes visible light absorption and scattering effects that may be used in optical coatings for eliminating blue light emission from display monitors, blocking UV light and for decorative applications. This study examines the achievement of functional properties provided by gold nanoparticles in a commercially established C60 fullerene-coated eyewear product. The gold nanoparticles used were sourced from recycling rapid lateral flow tests (LFIA), which use gold nanoparticles as test markers. After the gold`s recovery Ultrasonic Spray Pyrolysis (USP) with freeze-drying was used for the synthesis of new gold nanoparticles, to be used in optical coatings. The gold nanoparticles were examined with SEM, TEM, DLS, zeta potential, BET, and Vis-NIR for characterising their shapes and sizes, required for determination of the surface plasmon resonance effect. After applying the newly produced gold nanoparticles with fullerene C60 in a combined coating for eyewear lenses, the absorption and transmission of the lenses was determined for establishing changes in the coating functionality. The results show that enhancing the fullerene C60 coating with gold nanoparticles improves light absorption and reflectance for blue and UV light further, which may be evaluated as beneficial for the eyewear user, as the reduction of eye strain is improved due to the coating.

On the system Au(III)-HCl-A324H⁺Cl^-, liquid-liquid extraction experiments were used to define the extraction equilibrium and the corresponding extraction constant, and the facilitated transport of this precious metal, from HCl solutions, across a flat-sheet supported liquid membrane was investigated, using the ionic liquid as carrier, as a function of hydrodynamic conditions, concentration of gold(III) (0.01-0.1 g/L), and HCl (0.5-6 M) in the feed phase, and carrier concentration (0.023-0.92 M) in the membrane. An uphill transport equation was derived considering aqueous feed boundary layer diffusion and membrane diffusion as controlling steps. The aqueous diffusional resistance (Δf) and the membrane diffusional resistance (Δm) were estimated from the proposed equation, being their values 241 s/cm an 9730 s/cm, respectively. The performance of the present carrier was compared against results yielded by other ionic liquids, and also it was investigated the influence that other metals had on gold(III) transport both from binary or quaternary solutions. Gold was finally recovered from receiving solutions as zero valent gold nanoparticles.

Gold, present as electrum, in the Battle Gap, Ridge North-West, HW, and Price deposits at the Myra Falls mine, occurs in late veinlets cutting the earlier VMS lithologies. The ore mineral assemblage containing the electrum comprises dominantly galena, tennantite, bornite, sphalerite, chalcopyrite, pyrite and rare stromeyerite is defined as an Au-Zn-Pb-As-Sb association. The gangue is comprised of barite, quartz, and minor feldspathic volcanogenic sedimentary rocks and clay. Deposition of gold as electrum in the baritic upper portions of the sulphide lenses occurs at relatively shallow water depths beneath the sea floor. Primary, pseudosecondary, and secondary fluid inclusions, petrographically related to gold, show boiling fluid inclusion assemblages in the range of 123 to 173 °C, with compositions and eutectic melt temperatures consistent with seawater at approximately 3.2 wt% NaCl equivalent. The fluid inclusion homogenization temperatures are consistent with boiling seawater corresponding to water depths ranging from 15 to 125 metres. Slightly more dilute brines corresponding to salinities of approximately 1 wt% NaCl indicate that there is input from very low-salinity brines, which could represent a transition from subaqueous VMS to epithermal-like conditions for precious metal enrichment, mixing with re‑condensed vapour, or very low-salinity igneous fluids.

This study addresses the critical issue of dowel-bearing strength in Bambusa blumeana, a key sus-tainable construction material crucial for climate change mitigation. Given the lack of bamboo connection standards, the research focuses on determining the dowel-bearing strength of Bambusa blumeana, emphasizing factors such as dowel diameter, node placements, and the physical prop-erties of bamboo. A predictive equation is derived, enhancing the practicality of bamboo in struc-tural design. The results underscore a notable correlation between dowel diameter and character-istic strength, with implications for engineering practices. Node placements significantly affect dowel-bearing capacity, while bamboo's physical attributes, including thickness, culm diameter, and moisture content, exhibit modest correlations with strength. The derived equation aims to assist in structural design, mitigating splitting and bearing failures in bamboo structures. This research establishes a foundation for optimizing the use of Bambusa blumeana in sustainable construction, advancing the understanding of its dowel-bearing strength for improved sustainability and resili-ence in the construction industry. Future research suggestions include exploring bamboo-mortar composites, additional node placements, and employing more comprehensive empirical equations and curve-fitting techniques. The study advocates for further investigations with more diverse and larger bamboo samples to bolster robustness. Additionally, delving into bamboo ductility may offer valuable insights.

Within this paper, electro-mechanical long-term tests on a thrust bearing are presented. The effects of an additional electrical load on the bearing raceways and the used lubricant are investigated. Chemical and rheological investigations are presented which show the changes in the lubricant. These investigations are compared with the electrical loads and the occurring raceway damage. In addition, a comparison is made with mechanical reference tests. This procedure makes it possible to classify the changes that occur due to the electrical load and to distinguish the effects from each other. The background to these investigations is the increased occurrence of parasitic currents in electric motors, which can lead to damage to machine elements. The phenomena that occur here are new challenges in the development of drive trains.

Abstract In order to reduce the failure accidents of conventional packers, a kind of sealing structure of retrievable packers is designed, which can provide reference for optimizing the sealing performance and pressure capacity of packers. And theoretical calculation and experimental research on its sealing performance and pressure capacity are carries out through the finite element analysis on the contact with large deformation based on Abaqus and experimental. The results show that when the rubber cylinder of retrievable packers in the sealing process, the upper packer is subjected to greater stress and mainly plays a sealing role. In order to improve the sealing performance of packer, the height of upper and lower packer should be preferentially selected about 60 mm, the height of middle rubber cylinders should be about 50 mm, and the thickness of packer should be about 21 mm. The newly designed rubber cylinders can meet 150 ℃. Sealing and pressure-bearing function under the condition of 10000 Psi. The rubber cylinder of newly designed can satisfy the function of sealing and pressure-bearing under 140 ℃ and 10000 Psi. The whole experiment shows that the capacity of bearing pressure and sealing is stable, which can better meet the requirements of field use.

In Africa, 80% of households in urban areas are food insecure and is coupled with a dramatically changing urban food culture towards increased consumption of sugary and fatty foods. Consequently, incidences of obesity and undernourishment in many African cities are becoming escalating. Urban and peri-urban forestry emerges as a complementary measure to contribute towards elimination of urban hunger and improved nutritional security. However, there is scanty knowledge about the composition, diversity and socioeconomic contributions of urban food trees in African cities and this hinders policy discussions integrating urban forestry into the food security discourse. This paper examines the diversity and composition of the urban forest and food trees of Accra and sheds light on perceptions of urbanites regarding food tree cultivation and availability in the city. Using a mixed methods approach, about 105 respondents in six neighbourhoods of Accra were interviewed while over 200 100-m2 plots were surveyed across five land use types. Twenty-two out of the 70 woody species in Accra are edible. The food tree abundance in the city is about half of the total number of trees enumerated. The species richness and abundance of the edible trees and all trees in the city were significantly different among land use types (p<0.0001) and neighbourhood types (p<0.0001). The diversity of food bearing tree species was much higher in the poorer neighbourhoods than in the wealthier neighbourhoods. Respondents in wealthier neighbourhoods indicated that tree and fruit tree cover of the city was generally low and showed greater interests in cultivating fruit trees and expanding urban forest cover than poorer neighbourhoods. These findings demonstrate the need for urban food policy reforms that integrate urban grown tree foods in the urban food system/culture.

Screen-printed carbon electrode (SPCE) is a useful technique that has been widely used in the practical application of biosensors oriented to point-of-care testing (POCT) due to its characteristics of cost-effectiveness, disposability, miniaturization, wide potential window, and easy of electrode design. Compared with gold or platinum electrodes, surface modification is difficult because the carbon surface is chemically or physically stable. Oxygen plasma can easily produce carboxyl groups on the carbon surface, which act as scaffolds for covalent bonds. However, the effect of O2-plasma treatment on electrode performance remains to be investigated from an electrochemical perspective, and sensor performance can be improved by clarifying the surface conditions of plasma treated biosensors. In this research, we compared antibody modification by plasma treated and physical adsorption, using our original immunosensor based on gold nanoparticles (AuNPs). Consequently, the O2-plasma treatment produced carboxyl groups on the electrode surface, which changed the electrochemical properties owing to electrostatic interactions. It was also found that the surface became hydrophilic, inhibiting non-specific antigen adsorption. The sensitivity was 6.5 times higher than the Limit of Detection (LOD) using physical adsorption.

Oil and petroleum are strategic resources of great importance to national security. Petroleum and hydrothermal gold deposits may form together, with similar evolutionary trends in their formation, migration, and enrichment. Petroleum reservoirs and gold deposits are closely coupled under certain geological conditions. The solubility of gold in crude oil and its forms of occurrence are important in determining the mechanisms of interaction between gold and petroleum and in facilitating the recovery of gold from gold-bearing petroleum. In this study, the occurrence of gold in crude oil from the Linnan Depression in the Bohai Bay Basin, China, was studied using inductively coupled plasma–mass spectrometry and X-ray photoelectron spectroscopy. Concentrations of gold in crude oil from the Linpan and Shanghe oilfields averaged 44.5 ppb, which is well above the minimum concentration required for hydrothermal gold mineralization. Gold has an affinity with carbon, oxygen, and sulfur, and its concentration in crude oil is positively correlated with total acid and sulfur contents. We speculate that gold may exist in crude oil as complexes with organic acids or thiols, with crude oil thus being a transport medium for gold.

The present study reports on the fabrication and performance of ammonia sensors based on single-walled carbon nanotubes (SWCNTs) coated with gold nanoparticles (AuNPs). The sensors were subjected to controlled concentrations of ammonia at two temperatures, namely 25 oC and 140 oC, and their response was monitored through successive cycles of ammonia exposure and nitrogen purging. The results demonstrate that the sputtering-based deposition of AuNPs on SWCNTs led to the best sensor performance, characterized by a rapid increase in resistance values upon exposure to ammonia, and efficient recovery at 140 oC. By contrast, the sensor with chemically impregnated AuNPs exhibited a slower response time. Furthermore, a novel device was developed that combined MoS2-AuNPs (sputtering)-SWCNTs, and it showed improved sensor performance compared to the devices with only AuNPs. Overall, the study provides valuable insights into the fabrication and optimization of SWCNT-based ammonia sensors for various applications, especially for detecting and quantifying small amounts of ammonia (concentrations below 1 ppm).

The term STODS (Surgical Temporary Ocular Discomfort Syndrome) has been coined to describe the ocular surface perturbations induced by surgery. As one of the most important refractive elements of the eye, Guided Ocular Surface and Lid Disease (GOLD) optimization is fundamental to success in achieving refractive outcomes and mitigating STODS. Effective GOLD optimization and the prevention/treatment of STODS, requires an understanding of the molecular, cellular and anatomic factors that influence ocular surface microenviroment and the associated perturbations induced by surgical intervention. By reviewing the current understanding of STODS etiologies, we will attempt to outline a rationale for a tailored GOLD optimization depending on the ocular surgical insult. With a bench to bedside approach, we will highlight clinical examples of effective GOLD perioperative optimization can mitigate STODS deleterious effect on preoperative imaging and postoperative healing.

Gold nanoparticles are currently used for the treatment of cancer through a myriad of modalities and delivery approaches. Conjugation of tumor imaging Single Photon Emitting Computed Tomographic (SPECT) radiopharmaceutical to gold nanoparticles will allow systemic targeting and imaging of cancer tissues simultaneously. In this study, gold nanoparticles (AuNPs) were prepared using Epigallocatechingallate (EGCG), loaded with doxorubicin (Dox), and characterized before and after doxorubicin conjugation. Cytotoxicity of EGCG-AuNPs and Dox-EGCG-AuNPs were evaluated against breast carcinoma (MCF-7) and hepatocellular carcinoma (HepG-2) cell lines demonstrating high cytotoxic effects of Dox-EGCG-AuNPs against both cell lines. Doxorubicin was radiolabeled with ^99mTc and our new approach has optimized various labeling conditions resulting in a radiochemical yield of 93.5 ± 2.04%. Biodistribution of ^99mTc-Dox-EGCG-AuNPs was studied in normal and tumor bearing mice following I.V. and intratumoral injections at different time intervals. Results showed high uptake of the intravenously injected ^99mTc-Dox-EGCG-AuNPs in tumor tissue (22.45 %ID/g at 2 h). In addition, localized intratumoral injection of ^99mTc-Dox-EGCG-AuNPs showed extremely high levels of uptake in tumor (80.22 %ID/g at 15 min) with high retention for extended periods post injection. Our results present prospects for the utility of ^99mTc-Dox-EGCG-AuNPs as a multiplexed theranostic agent through SPECT imaging of tumor tissue and therapy through photothermal destruction of cancer tissue through the application of exogenous laser lights as well as through tyrosine phosphatases inhibitor (through EGCG), and topoisomerase II inhibitor (through doxorubicin) effects.

One of the largest in the archipelago silver-copper mineralisation at Mount Sigurdf′ellet in West Spitsbergen Island was found in 1990 by Russian geologists. Firstly genesis was caused exclusively with hydrothermal ore migration of a substance from the enclosing sandstone and siltstone of the Devonian age. But subsequent work on the ore and nearest rocks of the basement gave a new factual material on the geochemical characteristics of potential sources of metals and found new for this mineral occurrence - gold mineralization. Similarity of geochemical associations of Sigurd ore occurrence with nearby upper Proterozoic marble as the first likely source of ore substance and the second - caused by carbonate-containing streaks in Low Devonian sediments. Ore-formation, probably due to repeated hydrothermal processes and was completed in a period of tectono-magmatic activity in Jurassic-Cretaceous time.

Background: Ankle fractures, comprising about 10% of musculoskeletal injuries, pose a significant healthcare burden with an increasing incidence, particularly among an aging population. This study focuses on isolated Danis-Weber type B fractures. Recent trends lean towards surgical intervention for anatomical restoration, quicker recovery, albeit with associated complications. This report aims to assess the safety and efficacy of NewClip narrow locking plate system with early weight bearing in treating isolated fibular fractures. Methods: The study includes patients with Danis-Weber type B fractures surgically treated with NewClip narrow locking plate system. Exclusions involved nondisplaced fractures, open fractures, or those requiring additional fixation.Results: Fifteen patients were enrolled in this study. Minor complications, including wound swelling, were observed in two cases. The Visual Analogue Scale (VAS) for pain exhibited a steady decline postoperatively, with almost complete resolution by the third month. At three months, the FAOS demonstrated excellent results, and final follow-up at twelve months revealed complete osseous healing without complications.Conclusions: The use of this type of plates in treating isolated fibular fractures with early weight bearing shows promising results in terms of fracture healing, pain resolution, and functional outcomes warranting further investigation with larger cohorts.

There are two basic methods for radial external load distribution calculation on rolling elements in a rolling element bearing: the discrete method and the integral method. Solving the discrete equilibrium quasi-static equation using the Newton-Raphson scheme, more accurate results are derived than those based on the integral method, with small theoretical and computational efforts. The Sjövall’s radial integral factors, as well as some approximations proposed in the literature, for line- and point-contacts, are revisited. Numerical approximations for the Sjövall's radial integrals are proposed. The approximations’ errors with respect to the Sjövall’s radial integral’s numerical integration are shown. The numerical results of the displacement between inner and outer rigid rings, maximum hertzian contact deflection and the most loaded element load are shown for some ball and roller bearings, for radial external load ranging from 0 to 10,000 N, and for positive, negative and zero radial clearance, solving the discrete equilibrium quasi-static equation using the Newton-Raphson method. A total of 16 figures is shown in this work, many of which are made up of sub-figures. A total of 58 figures and sub-figures is shown.

: Clay covers a substantial portion of the Earth. Such soil covers Iraq’s central and southern regions, where the depth of the clay may reach 150 m. All enhancement techniques and methods for transporting large loads cease to function or become prohibitively expensive in such soils. In this case, thermal treatment is the most effective method. In this study, a novel heating system was created and produced utilizing gas as the heat source via boreholes that simulate reality. The borehole heating cases were planted inside soft clay soil to enhance the soil. Different parameters were investigated, including the spacing between boreholes (3, 4, and 5 times the outer diameter of the borehole), the heating depth (1, 1.5, 2, and 2.5 times the width of the model footing), the duration of heating (2, 4, 6, 8, and 10 hrs), and the pattern (square, circular, triangular). The results showed the strength and behavior of the soil treated with heated boreholes at varying spacings, depths, patterns, and heating periods. The best results were found for a spacing, depth, and heating time of three times the outer diameter of the borehole, two times the width of the footing model, and eight hours, respectively. The effect of the heated borehole casing pattern was small when the heated borehole casing was used. The experiments conducted on heated soil showed that the undrained shear strength (Cu) increased from 14 to 360 kPa and then dropped to 140 kPa (as an average with depth). In contrast, the average angle of internal friction (Ø) rose from 0 to 52 degrees and decreased to 16 degrees (as an average with depth) from the center of the heating model to the furthest point affected by heating. In addition, the EDS pattern showed that components like silicon, aluminum, and iron dropped at 300 °C and rose at 400 °C in the treated soils. At 200 °C, the calcium content rose, and then dropped dramatically at 400 °C. The carbon percentage increased at 300 °C and decreased at 400 °C. The elements’ proportions showed little change or remained stable at temperatures between 400 °C and 600 °C.

Clinching is a manufacturing method of mechanical joining two or more materials without the use of heat or additional components. This process relies on high plastic deformation to create a secure bond. Clinching technology is widely used for joining various grades and thickness of materials. Especially in the automotive industry, clinching is an alternative to spot resistance welding. However, the load-bearing capacity of clinched joints is comparatively lower when compared to resistance spot welded joints. This research aimed to enhance the load-carrying capacity of clinched joints. Experimental tests were conducted on clinched joints with locally modified microstructures to optimize their placement within the joint. The microstructure distribution in the clinched joint region was analysed using light and scanning electron microscopy, as well as microhardness measurements. Two material grades, micro-alloyed steels HX420LAD+Z and dual-phase ferritic-martensitic steels HCT600X+Z, were tested. Each grade underwent five groups of ten samples, subject to identical experimental conditions of local heating by resistance spot welding (RSW) and clinching. The application of RSW to the clinched joint area resulted in increase of load-bearing capacity for both joined types of materials.

This article discusses the issue of hardened steel machining. Many components in the engineering industry use hardening as the final heat treatment. These components usually occupy a significant position in a given assembly unit. They guarantee the correct operation of the entire technical equipment in total cooperation with other components. The quality of these components depends on the integrity of their surface. The production of these parts is usually carried out by traditional technological procedures. An example of such a technology is clearly grinding. However, this article discusses the application of other finishing technologies using tool material made of cubic boron nitride (CBN). The technology used is finishing turning with subsequent tumbling technology. The subject of the evaluation is the integrity of the surface. In this part of the experiments, there are mainly individual parameters of surface roughness. Compared components are bearing rings, in this case the inner surface of the housing ring.

Reinforced concrete (RC) columns are often placed under confinement to increase their strength and ductility. Carbon fiber reinforced polymer (CFRP) materials have recently been recognized as favorable confinement systems. At present, a number of national standards and codes dedicated to the design of concrete components strengthened with CFRP in general and CFRP confinement in particular are available. These sets of rules provide design equations for confined reinforced concrete columns with circular and rectangular cross sections. Most of the standards and codes exhibit significant differences, including the used predictive models limitations, observed effects, and covered loading conditions. In this paper, five international standards and design guidelines are introduced and discussed. The purpose is to present a constructive and critical assessment of the state-of-the-art design methodologies available for CFRP confined RC columns and to discuss effects not previously considered properly. Therefore, some recent research efforts and findings from the Leipzig University of Applied Sciences are also introduced. The obtained data is used for a comparative study of the guideline predictive equations. Furthermore, it is shown that some new findings concerning the rupture strength and the maximum strength plus accompanying axial strain of a CFRP confined column are suitable to improve the current guidelines.

A practical method is presented to estimate rare earth elements (REE) concentrations in magmatic vapour phase (MVP) in equilibrium with water-saturated granitic melts based on empirical fluid-melt partition coefficients of REE (k_P^REE). The values of k_P^REEcan be calculated from a set of new polynomial equations linking to the chlorine molality (m_Cl^v) of the MVP associated with granitic melts, which are established via a statistical analysis on the existing experimental dataset. These equations may be applied to the entire pressure range (0.1 to 10.0 kb) within the continental crust, suggesting that light REEs behave differently in magmatic fluids, i.e. either being fluid compatible with higher m_Cl^v or fluid incompatible with lower m_Cl^v values. In contrast, heavy REEs are exclusively fluid incompatible and partition favourably into granitic melts. Consequently, magmatic fluids tend to be rich in LREE relative to HREE, leading to REE fractionation during the evolution of magmatic hydrothermal systems. Maximum k_P^REEvalue for each element is predicted and presented in a REE distribution diagram constrained by the threshold of m_Cl^v. REE contents of the granitic melt is approximated by whole-rock analysis, so that REE concentrations in the associated MVP would be estimated from the value of k_P^REE given chemical equilibrium retains. Two examples are provided respectively, to show the use of this method as a REE tracer to fingerprint the source of ore-fluids responsible for the Lake George intrusion-related Au-Sb deposit in New Brunswick (Canada), and for the Bakircay Cu-Au (-Mo) porphyry systems in northern Turkey.

In this review, we covered the recent advances in synthesis of gold nanoparticles and their uses in degradation of dyes. This study provides framework to develop a low cost, ecofriendly and highly efficient synthesis of gold nanoparticles. These synthetic methods do not produce any toxic byproduct. The present study is focus on removal of dyes by Au-NPs because gold nanoparticles act as good absorbent for dyes in short time. Synthesis of Au-NPs from plant extract e.g. marine alga, Scutellarin Barbata, A.nigra, Fruit peels, Bacillus marisflavi from raw silk cocoons, amylopectin and poly acrylic acid, L.asparagine, Grephene oxide, IPEI coated Au-NPs. The synthesizes Au-NPs were used further for removal of dyes like methylene blue (MB), Rhodamine B (RB) Degradation, methylene orange, acid red degradation, Congo red.

The high reactivity of acetylene group the formation of strong chemical bonds with active sites on mineral surfaces, thereby improving the flotation performance of gold minerals. This study utilized Density Functional Theory (DFT) to analyse the quantum chemical parameters of structure, Mulliken population, and the frontier orbitals of a thioester collector containing an acetylene group, PDEC (prop-2-yn-1-yl diethylcarbamodithioate). PDEC is compared with analogous thioester collectors Z-200 and Al-DECDT, and the interaction mechanism of PDEC on the Au(1 1 1) surface is simulated, followed by empirical validation through adsorption experiments. The findings indicate that S atom of PDEC in the carbon-sulfur group exhibit shorter covalent bond lengths, and reduced carbon-sulfur double bonds and Mulliken population, resulting in enhanced electron localization. This confers greater selectivity to PDEC during its adsorption on mineral surfaces. Frontier orbital analysis shows that the electrons of acetylene group possess a notable electron-accepting capacity, significantly influencing frontier orbital energy of PDEC and playing a pivotal role in the bonding interaction with mineral surfaces. Both the S atom in carbon-sulfur group and its acetylene group establish stable adsorption structures with the A(111) surface in a single coordination mode. The adsorption energy sequence is PDEC > Al-DECDT > Z-200. Partial density of states demonstrates that S 3p orbit of carbon-sulfur group hybridize with Au 5d orbit, while the C 2p orbit of the acetylene group engage in weaker back-donation bonding with Au 5d orbit. This is corroborated by electron density difference and post-adsorption Mulliken population analyses, revealing that S atom of carbon-sulfur group in PDEC donate electrons to Au atom, forming dominant positive coordination bonds, whereas the acetylene group accepts partial electrons from Au atom, resulting in weaker back-donation bonds. The adsorption experiments align with the DFT adsorption energy results.

Although effective in term of chance of future live birth, the current methods for fertility preservation such as oocytes, embryo or ovarian tissue cryopreservation cannot be offered to all cancer patients and in all clinical contexts. Expanding options for fertility preservation is crucial to address the need to encompass all situations. One emerging strategy is pharmacoprotection, which is non-invasive and has the potential to fill existing gaps in fertility preservation. Besides the identification of the most efficient therapeutic agent itself, the potential off-target effect re-mains one of the main limitation of this strategy for clinical application, particularly when healthy ovarian tissue is targeted. This review focuses on the advances in pharmacoprotective approaches and the challenge of targeting the ovaries to deliver these agents. The unique properties of gold nanoparticles (AuNPs) make them an attractive candidate for this purpose. We discuss how AuNPs meet many of the requirements for an ideal drug delivery system, as well as the existing limitations that have hindering the progression of AuNPs research into more clinical trials. Additionally, the review highlights microRNA (miRNA) therapy as a next-generation approach to address the issues of fertility preservation and discusses the obstacles that currently impede its clinical availability.

Currently available DNA detection techniques frequently require compromises between simplicity, speed, accuracy, and cost. Here, we propose a simple, label-free and cost-effective DNA detection platform developed at screen printed carbon electrodes (SPCEs) modified with reduced graphene oxide (RGO) and gold nanoparticles (AuNPs). The preparation of the detection platform involved a two-step electrochemical procedure based on GO reduction onto SPCEs followed by the electrochemical reduction of HAuCl4 to facilitate the post-grafting reaction with AuNPs. The final sensor was fabricated by the simple physical adsorption of a single-stranded DNA (ssDNA) probe onto AuNPs-RGO/SPCE electrode. Each preparation step was confirmed by morphological and structural characterization using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy, respectively. Furthermore, the electrochemical properties of the modified electrodes have been investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The results demonstrated that the introduction of AuNPs onto RGO/SPCEs led to an enhancement in surface conductivity, characteristic that favored an increased sensitivity in detection. The detection process relied on the change in the electrochemical signal induced by the binding of target DNA to the bioreceptor, and was monitored particularly by the change in the charge transfer resistance of a [Fe(CN)6]4−/3− redox couple added in the test solution.

The gold nanoparticle (AuNP) was synthesized using the well-known Turkevich method. This article explains didactic step-by-step of the synthesis, showing pictures of the entire process, including a well-explained mechanism and characterization study. The synthesis includes the reduction of NaAuCl4 using sodium citrate in high temperature (around 90 ⁰C). The two main mechanisms used to explain the AuNP synthesis via Turkevich method were explained. The first mechanism considerate that a nanowire intermediary and the other proposed that aggregate intermediates are not formed at any time during the synthesis. The materials (NaAuCl4 and AuNP) were characterized by UV-Vis, SEM, AFM, XRD and DLS. The UV-Vis exhibit an absorption maximum in 521 nm because the surface plasmon resonance (SPR) absorption band of AuNP. The SEM images of NaAuCl4 presents crystals with cubic shapes, while the AuNP presents average particle size of about 16-25 nm and particles that appear mainly spherical. To confirm the particles shapes, the AFM was conducted and it was possible to observe clearly the individual spherical nanoparticles. The XRD of AuNP showed the four main characteristic peaks for silver corresponding to (111), (200), (220) and (311) planes, confirming the cubic (FCC) silver. The DLS presented the average particle size of 3.3 ± 0.9 nm and the polydispersity index (PDI) of 0.574. In summary, the AuNP was synthesized using a simple and fast method. The result was a spherical and ultrasmall particle, that can be used is several applications.

Nanoscale imaging with the ability to identify cellular organelles and protein complexes has been a highly challenging subject in secondary ion mass spectrometry (SIMS) of biological samples. This is because only a few isotopic tags can be used successfully to target specific proteins or organelles. To address this, we have generated gold-nanoprobes, in which gold nanoparticles are conjugated to nanobodies. The nanoprobes were well suited for specific molecular imaging using NanoSIMS at subcellular resolution. They demonstrated to be highly selective to different proteins of interest, and sufficiently sensitive for SIMS detection. The nanoprobes offer the possibility of correlating the investigation of cellular isotopic turnover to the positions of specific proteins and organelles, thereby enabling an understanding of functional and structural relations that are currently obscure.

Gold nanoparticles, were deposited in titanium oxide (TiO2) Degussa-P25 with the Photodeposition method in the presence of UV light at different concentrations. It was determined by diffuse reflectance (DF), Scanning electron microscopy (SEM), that the Photodeposition method is effective for the inclusion of gold particles on the surface. The catalyst band gap showed a reduction to 2.9 e.V, as well as it was observed that the gold-doped catalyst shows absorption in the visible light range around 500 to 600 nm. The percentage of deposited gold nanoparticles was determined by energy dispersive spectroscopy (EDS). The experimental data were analyzed using different analytical techniques (UV-Vis spectrophotometry, TOC total organic carbon), with these results a carbon-based mass balance and reaction kinetics were generated using the Langmuir-Hinshelwood (LH-HW) heterogeneous catalysis model. For the estimation of the kinetic constants, the non-linear regression of the Levengerd Marquad algorithm was used, with these results, kinetic models of the degradation of the molecule and the generation and consumption of Organic Intermediate Products (OIP) were generated.

A novel catechol (CA) biosensor was developed by the immobilization of tyrosinase (Tyr) onto in situ electrochemical reduction graphene (EGR) on choline functionalized gold nanoparticals (AuNPs–Ch) film. The results of UV–visible spectra indicated that Tyr retained its original structure in the film. And electrochemical investigation of the biosensor showed a pair of well–defined, quasi–reversible redox peaks with E_pa= –0.0744V and E_pc= –0.114 V (vs. SCE) in 0.1 M, pH 7.0 sodium phosphate buffered saline at the scan rate of 100 mV/s. The transfer rate constant k_s was 0.66 s^–1. The Tyr–EGR/AuNPs–Ch showed a good electrochemical catalytic response for the reduction of CA, with the linear range from 0.2 to 270 μM and a detection limit of 0.1 μM (S/N= 3). The apparent Michaelis–Menten constant was estimated to be 109 μM.

The emergence of electric vehicles has brought new issues such as the problem of rolling element bearings (REBs) operating at high speeds. Losses due to these components in mechanical transmissions are a key issue and must therefore be taken into account right from the design stage of these systems. Among these losses, the one induced by the motion of rolling elements , known as drag loss, becomes predominant in high-speed REBs. Although an experimental approach is still possible, it is difficult to isolate this loss in order to study it properly. A numerical approach based on CFD is therefore a possible way forward, even if other issues arise. The aim of this article is to study the ability of such an approach to correctly estimate the drag coefficient associated with the motion of rolling elements. The influence of the numerical domain extension, the mesh refinement, the simplification of the ring shape and the presence of the cage, on the values of the drag coefficient is presented. While it seems possible to compromise on the calculation domain and mesh size, it appears that the other parameters must be taken into account as much as possible to obtain realistic results.

Improper design of friction pendulum bearings can lead to poor seismic reduction performance and may result in the failure of local vulnerable components. And the parameter design of friction pendulum bearings mainly relies on experience and verification calculations at present. This paper proposes an adaptive genetic algorithm considering the overall evolution state of the population, adjusting crossover and mutation probabilities adaptively based on individual fitness and population diversity. Compared to traditional algorithms, it exhibits better global search capabilities and convergence efficiency. Combining the improved genetic algorithm with finite element models, a parameter optimization method is proposed. The parameters of friction pendulum bearings are optimized, providing reference for the design of seismic isolation devices.

The three-dimensional morphology of frictional sub-surfaces holds significant importance for studying tribological issues. However, the uniformity of horizontal datum in 3D scanning is limited for curved surfaces, resulting in the inability to obtain accurate contour characterization parameters from the scanning results. This study aims to address this issue by constructing regular surface equations and normalizing the 3D profiler scanning results. By fitting the data, a "plane" surface representative of the surface features is obtained, and the paper demonstrates this approach on the surface morphology of different worn parts in the frictional area of spherical bearings located in the specific environment of the Three Gorges gate. The results indicate that the obtained "plane" effectively reconstructs the three-dimensional morphology map of the regular surface. Moreover, this reconstructed plane not only clearly illustrates the surface characteristics but also provides the foundation for analyzing the wear mechanism.

A frequent problem in Geotechnics is the soils with inadequate physical-mechanical properties before the efforts to which they will be subjected by the constructions, incurring cost overruns caused by their engineering improvement. The need to improve the engineering properties of soils is not recent, currently observing that the most common alternatives are binders such as cement and lime. The climate change observed in recent decades and the uncontrolled emission of greenhouse gases have motivated Geotechnical and Geoenvironmental researchers to seek mechanisms for soil reinforcement from a more sustainable and environmentally friendly approach by proposing the use of recycled and waste materials. An alternative is natural fibers, which can be obtained as waste from many agro-industrial processes, implying their high availability and low cost. Sawdust as a by-product of wood processing has a rough texture that can generate high friction between the fiber and the matrix of the soils, leading to a significant increase in its shearing strength and bearing capacity. This concept of improving the properties of soils using natural fibers distributed randomly is inspired by the natural phenomenon of grass and/or plants that when growing on a slope can effectively stabilize a said slope.

Wear usually occurs in the loaded part of hydrodynamic bearings and leads the bearing geometry imperfections. This paper investigates the effects of wear-induced geometric imperfections of tilting pad journal bearings (TPJBs) on the dynamic behavior of the system. Furthermore, the effect of wear on the journal-bearing rub-induced contact pressure severity is investigated. A novel tribo-dynamic model is proposed for a flexible rotor-worn TPJB which integrates a mixed elastohydrodynamic model with a rotor-worn TPJB thermal and dynamic model to assess the effects of the bearing wear progression on the rotor-TPJB behavior. Based on the results, wear changes the temperature distribution of the pads and oil film as well as the dynamic behavior of the system. Dynamic simulations reveal a higher vibration level and contact pressure for the worn TPJBs near the system's critical speed and service speed. Finally, thermal and dynamic condition indicators are suggested to detect TPJB wear severity at its early stages.

To further explore the bearing capacity and sustainable construction of vacuum drainage pipe (VDP) piles, field tests were carried out to compare and analyze the ultimate single pile bearing capacity, pile side friction and pile end resistance of ordinary piles and vacuum drainage pipe piles. The effect of the VDP pile on energy conservation and emission reduction in practical projects is discussed. The results shows that the VDP pile basically eliminated the soil squeeze and did not cause excessive relative displacement of pile and soil after vacuum consolidation. The VDP pile enhances pile side friction resistance, resulting in a 17.6% increase in ultimate bearing capacity compared to traditional piles. The VDP pile method can reduce carbon emissions by 31.4% compared to traditional methods. This study provides guidance for the production and design of VDP piles in the future and demonstrates their potential for energy conservation and emission reduction benefits compared to traditional methods.

The purpose of feature selection is to find important features from the original high-dimensional space. As atypical feature selection algorithm, Locally linear embedding(LLE)-based feature selection algorithm, which applies the idea of LLE to the graph-preserving feature selection framework, has been received wide attention. However, LLE-based feature selection framework is sensitive to noise and K-nearest neighbors. To address these problems, an improved LLE-based feature selection algorithm, robust LLE (RLLE) vote, is proposed. In this algorithm, $l_1$ and $l_2$ regularization are introduced into the high-dimensional reconstruction model of LLE. Furthermore, RLLE vote also proposes a criterion to measure the difference between the reconstruction features and the original features, and then the importance features can be selected by this criteria. Extensive experiments are carried out on a benchmark fault data set and the bearing data set collected from our own laboratory, and the experimental results demonstrate that RLLE vote achieves the most significant performance compared existing state-of-art methods.

The use of new developed high-strength steel in concrete members can reduce steel bars congestion and construction costs. This research aims to study the behavior of concrete columns reinforced with new developed high-strength steel under eccentric loading. Ten reinforced concrete columns were fabricated and tested. The test variables are transverse reinforcement amount and yield strength, eccentricity, and longitudinal reinforcement yield strength. The failure patterns are compression and tensile failure for columns subjected to small eccentricity and large eccentricity, respectively. The same level of post-peak deformability and ductility only can be obtained with lower amount of transverse reinforcement when high-strength transverse reinforcements are used in columns subjected to small eccentricity. The high-strength longitudinal reinforcement can improve bearing capacity and post-peak deformability of concrete columns. Besides, three different equivalent rectangular stress block (ERSB) parameters in predicting bearing capacity of columns with high-strength steel were discussed based on test and simulated results. It is concluded that the Code of GB 50010-2010 overestimates the bearing capacity of columns with high-strength steel, whereas bearing capacities computed using Codes of ACI 318-14 and CSA A23.3-04 agree well with test results.

We describe a competitive colorimetric assay that enables rapid and sensitive detection of galactose and reduced nicotinamide adenine dinucleotide (NADH) via colorimetric readouts and demon-strates its usefulness for monitoring NAD+-driven enzymatic reactions. We present a sensitive plasmonic sensing approach for assessing galactose concentration and the presence of NADH using galactose dehydrogenase immobilized gold nanostars (AuNS-PVP-GalDH). The AuNS-PVP-GalDH assay remains turquoise blue in the absence of galactose and NADH; however, as galactose and NADH concentrations grow, the reaction well color changes to a characteristic red color in the presence of an alkaline environment and metal ions catalyst (detection solution). As a result, when galactose is sensed in the presence of H2O2, the colored response of the AuNS-PVP-GalDH assay transforms from turquoise blue to light pink, then to wine red in a con-centration-dependent manner discernible to the human eye. This competitive AuNS-PVP-GalDH assay could be a viable analytical tool for rapid and convenient galactose quantification in re-source-limited areas.

Gold- and MnO₂- nanozymes are well-known for their enzyme-like activity. In this regard, initially, gold- and MnO₂- nanozymes were synthesized by simple and green methods. Afterward, the kinetic studies were performed using the Michaelis–Menten model for both gold- and MnO₂- nanozymes. The kinetic parameters including K_m and V_max were calculated via the construction of the linear plot of Lineweaver–Burk for both nanozymes. The results showed a V_max and K_m of 185 nM sec^-1 and 47 nM sec^-1 for the gold- and MnO₂- nanozymes, in order. The ratio of V_max(gold)/V_max(MnO₂) was found to be about 4.0 which pointed that the catalytic efficiency of gold-nanozymes is 4.0-fold higher than the catalytic efficiency of MnO₂- nanozymes. The K_m value was found to be 0.72 mM and 1.6 mM for the as-prepared gold- and MnO₂- nanozymes, respectively, and the K_m of MnO₂-nanozymes is 2.2-fold higher than that of gold nanozymes. Since the Km shows the affinity of substrate for binding to nanozyme active nodes (lower K_m=higher affinity), it is consultable that the substrate affinity toward MnO₂-nanozymes is 2.2-fold lower than that of the gold-nanozymes. Considering the above results, the as-prepared gold nanozymes are very stronger peroxidase-like mimics than the metal oxide MnO₂-nanozymes.

Liquid biopsy has been developed to diagnose and monitor cancer. Despite the recent advances in investigating early cancer detection and diagnosis strategies, there is still a lack of improvements in capturing (CTCs). To archive this, we developed an efficient CTC detection system by integrating gold nanoparticles and a microfluidic platform, which can achieve CTC capture within 120 min. The microdevice was functionalized by immobilizing antibodies specific to the target cells. The method was tested with spiked tumor cells in whole human blood with three pancreatic cancer cell lines and compared with purified cancer cells suspended in a phosphate buffer solution. Our results captured pancreatic cancer cells spiked in blood samples with efficiency (90±3.2)% and were used to isolate CTCs from patients with metastatic pancreatic cancer. This methodology will enable the production of functionalized, patterned surfaces that interact with tumor cells, enhancing the selective capture of CTCs from biological assays.

Controlling water and food contamination by pathogenic organisms requires quick, simple, and low-cost methods. using affinity between mannose and type I fimbriae in the cell wall of Escherichia coli bacteria as evaluation elements compared to the conventional plate counting technique enables a reliable sensing platform for the detection of bacteria. In this study, a simple new sensor based on electrochemical impedance spectroscopy (EIS) for rapid and sensitive detection of Escherichia coli was developed. Biorecognition layer of the sensor was formed by covalent attachment of p-carboxyphenylamino mannose (PCAM) to gold nanoparticles (AuNPs) electrodeposited on the surface of glassy carbon electrode (GCE). The resultant structure of PCAM was characterized and confirmed using FTIR. The developed biosensor demonstrated a linear response with a logarithm of bacterial concentration (R2 = 0.998) in the range of 1.3 × 10 1~ 1.3 × 106 CFU.mL−1with the limit of detection of 2 CFU.mL−1 within 60 min. The sensor did not generate any significant signals with two non-target strains, demonstrating high selectivity of the developed biorecognition chemistry. Selectivity of the sensor and its applicability to analysis of the real samples was investigated in samples of tap water. Overall, the developed sensor has shown to be promising for the detection of E. coli pathogen in water due to its high sensitivity, short detection time, low cost, high specificity, and user-friendliness.

Gold nanoparticles have been increasingly used in several electronic, material fabrication, and biomedical applications. Several methods have been reported to prepare gold nanoparticles of various shapes and sizes with different photophysical properties. Although useful to prepare gold nanoparticles, most of the methods are not stable enough and undergo degradation, if stored at room temperatures (up to 30 °C) for a few days. In this paper, we report a novel environmentally friendly method to synthesize self-assembled gold nanoparticles in cruciform shapes by using leaf extract of Cannabis indica as a reducing agent without the aid of any polymers or additional chemicals. The nanoparticles are found to be stable for more than a month when stored at room temperature (30 °C). They were able to form stable conjugates with bovine α-lactalbumin protein that may possess anti-cancerous properties.

Mining and processing tailings often contain significant amounts of valuable metals, that can represent valuable sources of secondary raw materials. Especially this is case in early-stage operations, in which the head grades were higher, and the tailings were higher grade. These tailings can also present a substantial risk to the environment. Serbia has copper deposits which have been exploited since ancient times, and these operations have generated large amounts of mineral processing tailings. The main objective of this study is to show how valuables can be recovered from chemically and mineralogically challenging tailings. After detailed chemical and mineralogical characterization, the laboratory scale flotation tests focused on evaluating the effect of particle size, different types of collectors, pH, and pulp potential. Based on the test work, copper and gold can be recovered effectively into pyrite concentrate

Cancer is one of the health concerns in modern societies. The application of nanotechnology in medical sciences has created new possibilities for the diagnosis, imaging and the treatment of tumors in humans. The present article reviews the application of marine-based gold nanoparticles in diagnosing and treating cancer. The main data were collected from research article on the application of different marine-based gold nanoparticles in detecting and imaging cancer cells as well as in drug delivery system in treatment of cancer. Chitosan is the most used marine natural compound used to fabricate gold nanocomposites and the most reported application of this type of nano-composites is related to drug delivery system. Despite the excellent anticancer potential of different marine natural products, less studies have been conducted on the use of their compositions with gold nanoparticles in cancer therapy than other materials. Moreover, most reports available in this filed are related to their application as a drug delivery system not anticancer drug. In general, there are still challenges and limitations to the use of nanoparticles in medicine, it is hoped that in the near future nanoparticles will create a dramatic revolution not only in oncology but also in medicine.

The Neoproterozoic (900-600 Ma) Arabian Nubian Shield is an example of Precambrian plate tectonics and arc accretion. The Western Ethiopian Shield (the southern extension of ANS) is geo-tectonically a characteristic of lower grades of Metavolcano-sedimentary sequences of ANS intruded by associated felsic granitoid and mafic bodies and at the same time it is contained of gneisses rocks of the MB. The Gold mineralization and alterations initiating throughout the Tulu Kapi syenite are in the form of in enechelon vein arrays and related structures, which are controlled by conjugate shear zones in the syenite and steep N-S striking structures. The earliest recorded deformation and alterations revealed the syenite albitization which is the one hosting for gold mineralization and it has been widely overprinted by multistage hydrothermal system that appears to have been controlled mainly by veins, crackle zones, fractures and minor breccia zones. Primary gold mineralization displays spatial and temporal relationship with Tulu Kapi syenite and the Kapi gabbro, both of which host gold mineralization, are 738.3±2.6 Ma and 699.5±2.7 Ma period, respectively, in a volcanic arc subduction syn-collisional tectonic setting by the fractionation of underplated, LREE-enriched basaltic magma with substantial crustal input to possible crustal melting. The underplated basaltic magma had been sourced from LREE-enriched mantle by subduction of sediment laden crustal slabs at a subduction zone. Fractional crystallization involved formation of Ca-rich plagioclase, which continually reacted with hydrothermal fluids to more fractionated Na-rich plagioclase, forming the gold mineralization hosting altered (albitized) syenites. The Pan-African orogeny, and associated regional metamorphism and magmatism, generated large-scale movements of gold and base metal-bearing fluids in the crust, channelized along complex fractures into regional NE-SW foliation in Ethiopia (e.g., western Ethiopia). However, these gold-rich alkalic magmas are so modified by crustal processes that evidence of their genetic relationship with gold become obscured. The primary ore mineral assemblage of quartz veins and veinlets, and associated mineralised syenite within Tulu Kapi area consists of pyrite, galena, chalcopyrite, hematite, and gold. The major and trace element composition of ore- forming fluids from the mineralised vein, barren and granitic intrusion is still largely unknown, yet could provide important and more direct evidence for the fluid source(s). This is vital in establishing a direct genetic link between syenite and other granitoid intrusion, and gold mineralization.

For some decades, the scientific community has been looking for alternatives to the use of fossil fuels that allow the planet's sustainable and environmentally friendly development. To do this, attempts have been made to mimic some processes that occur in nature, among which the photosystem-II stands out, which allows water splitting operating with different steps to generate oxygen and hydrogen. This research presents promising results using synthetic catalysts, which try to simulate some natural processes, and which are based on Au@ZnO-graphene compounds. These catalysts were prepared by incorporating different amounts of gold nanoparticles (1 wt.%, 3 wt.%, 5 wt.%, 10 wt.%) and graphene (1 wt.%) on the surface of synthesized zinc oxide nanowires (ZnO NWs), and zinc oxide nanoparticles (ZnO NPs), along with a commercial form (commercial ZnO) for comparison purposes. The highest amount of hydrogen (1,127 µmol/hg) was reported by ZnO NWs with a gold and graphene loadings of 10 wt.% and 1 wt.%, respectively, under irradiation at 400 nm. Quantities of 759 µmol / hg and 709 µmol / hg were obtained with catalysts based on ZnO NPs and commercial ZnO, respectively. The photocatalytic activity of all composites increased with respect to the bare semiconductors, being 2.5 times higher in ZnO NWs, 8.8 times for ZnO NPs and 7.5 times for commercial ZnO. The high photocatalytic activity of the catalysts is attributed, mainly, to the synergism between the different amount of gold and graphene incorporated, and the surface area of the composites.

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.

Hybrid metal-halide perovskites have emerged as leading class of semiconductors for photovoltaic devices with remarkable light harvesting efficiencies. The formation of methylammonium lead iodide (CH₃NH₃PbI₃) perovskite into mesoporous titania (TiO₂) scaffold by a sequential deposition technique is known to offer better control over the perovskite morphology. The growth reactions at the mesoporous TiO₂ film depend on reactants concentration in the host matrix and the reaction activation energy. Here, we are characterizing formation of CH₃NH₃PbI₃ perovskite in mimic solar cell photoelectrodes utilizing the developed NanoPlasmonic Sensing (NPS) approach. Based on dielectric changes at the TiO₂ mesoporous film interface, the technique provides time-resolved spectral shifts of the localized surface plasmon resonance that varies widely depending on the different operating temperatures and methylammonium iodide (CH₃NH₃I) concentrations. Analytical studies included Ellipsometry, Scanning Electron Microscopy, and X-ray diffraction. The results show that perovskite conversion can be obtained at lower CH₃NH₃I concentrations if reaction activation energy is lowered. A significant finding is that the NPS response at 350 nm mesoporous TiO₂ can widely change from red shifts to blue shifts depending on extent of conversion and morphology of perovskite formed at given reaction conditions.

Gold nanoparticles (AuNPs) are currently under intense investigation for biomedical and biotechnology applications, thanks to their ease in preparation, stability, biocompatibility, multiple surface functionalities and size-dependent optical properties. The most commonly used method for AuNPs synthesis in aqueous solution is the reduction of tetrachloroauric acid (HAuCl₄) with trisodium citrate. We observed variations in the pH and concentration of the gold colloidal suspension synthesized under standard conditions, verifying a reduction in the reaction yield by around 46% from pH 5.3 (2.4 nM) to pH 4.7 (1.29 nM). Citrate-capped AuNPs were characterized by UV-visible spectroscopy, TEM, EDS and zeta-potential measurements, revealing a linear correlation between pH and the concentration of the generated AuNPs. This result can be attributed to the adverse effect of protons both on citrate oxidation and on citrate adsorption onto the gold surface, which is required to form the stabilization layer. Overall, this study provides insight into the effect of the pH over the synthesis performance of the method, which would be of particular interest from the point of view of large-scale manufacturing processes.

The possibility of releasing gold nanoparticles (GNP) into the environment has been rapidly increasing with the wide spread and flourishing application of gold nanoparticles (GNPs) in a wide range of areas. Consequently, environmental effects of GNP, especially toxicities to living organisms have drawn great attention. However, their toxicological characteristics still remain unclear. Fungi, as the decomposers of the ecosystem, interact directly with the environment and critically control the overall health of the biosphere. Thus, their sensitivity to GNP toxicity is particularly important. The aim of this study was to evaluate the role of shape and size of GNPs on their toxicities to fungi, which could help reveal the ecotoxicity of GNPs. Aspergillus niger, Mucor hiemalis and Penicillium chrysogenum were chosen for toxicity assessment, and spherical and star/flower-shaped GNPs sized from 0.7 nm to large aggregates of 400 nm have been synthesised. After exposure to GNPs and their corresponding reaction agents and incubation for 48 hours, the survival rates of each kind of fungus was calculated and compared. The results indicated that fungal species was the major determinant of the variation of survival rates, whereby A. niger was most sensitive and M. himalis was least sensitive to GNP exposure. Additionally, larger and non-spherical GNPs had relatively stronger toxicities.

Ceria, zirconia and mixed cerium-zirconium mesoporous oxides were synthesized and used as supports for sulfur and gold species. The materials were characterised using selected advanced techniques (ICP-OES, elemental analysis, XPS, XRD, N₂ adsorption and desorption isotherms, UV-vis, ATR-FTIR, TPR-H₂, TG-DTA) which allowed monitoring of the oxidation state of metals (cerium and gold) and the surface properties of the catalysts, in particular the concentration of the components on the surface and in the bulk of materials. The interactions between gold, sulfur and metals from oxides were considered. The goal of this work was studied the changes in the chemical composition of materials and the oxidation states of cerium species after the modification of oxides with sulfur and gold species and the estimation of the influence of these changes on the surface properties. The chemical composition of surface affects the mobility of surface oxygen and the oxidation state of cerium, which can play the role of redox sites (e.g. Ce³⁺/Ce⁴⁺ species), and therefore it strongly influences on the adsorption of hydrogen sulfide and then gold loading. Additionally, gold catalysts modified with sulfur species were tested in the reaction of glycerol oxidation in the liquid phase at basic conditions as the test reaction of the catalytic oxidation of organic pollutants from water.

A novel concrete beam-column connection utilizing L-shaped steel bars is proposed to address the growing demand for prefabricated buildings and to ensure good seismic performance in such beam-column structures. After positioning two prefabricated beams with L-shaped tendons into the designated connection points at the top and bottom of the columns, concrete is poured into the post-cast section of the joint and the composite beam area, realizing a connection between the beams and columns. Quasi-static tests were performed on four combined nodes and one cast-in-place node to investigate their failure modes and stress mechanisms. Seismic performance indices, including hysteretic curves, skeleton curves, ductility performance, and energy dissipation capacity, were analyzed. Concurrently, the finite element method (FEM) was employed for parameter analysis. By integrating the test and FEM results, an equation for calculating the shear capacity of the connection was derived. The findings demonstrate that the hysteresis curve of the newly developed prefabricated joints is relatively full, with their overall performance index comparable to that of cast-in-place joints. Additionally, enhancing the post-casting area of concrete, the length of the L-shaped bars, the concrete strength in the composite beam region, the axial compression ratio, or the steel tube dimensions can effectively improve overall performance. The derived equation for the shear-bearing capacity of the connection satisfies design and application requirements.

A flexible structure is applied to improve the lubrication performance of a misaligned journal bearing. The journal bearing is representative sliding bearing and there are damages due to metal-to-metal contact by misalignment. Since misalignment is an unavoidable phenomenon, a journal bearing with a flexible structure was proposed as a way to improve it. The lubrication characteristics of the bearing are evaluated numerically under steady-state condition. EHL (elastohydrodynamic lubrication) analysis considering elastic deformation was performed. The lubrication performance is compared in accordance with variation of the geometry of the flexible structure and evaluated based on the minimum film thickness. Moreover, the results of the journal bearing with flexible structure are compared with those of the journal bearing without the flexible structure. The flexible structure is then applied in the form of a groove to the area supporting high load on the journal bearing; it is elastically deformed by the generated oil-film pressure, which helps to obscure a larger oil film. Through numerical analysis, it is found that the journal bearing with flexible structure can improve the lubrication performance in the misaligned condition.

Alum sludge is a byproduct of water treatment plants and its use as a soil stabilizer has gained increasing attention due to its economic and environmental benefits. Its application has been shown to improve the strength and stability of soil, making it suitable for various engineering applications. However, to go beyond just measuring the effects of alum sludge as a soil stabilizer, this paper explores the use of artificial intelligence (AI) methods to predict the California bearing ratio (CBR) of soils stabilized with alum sludge. Three AI methods, including two black box methods (artificial neural network and support vector machines) and one grey box method (genetic programming), were used to predict CBR based on a database with nine input parameters. The results showed that all three AI models were able to predict CBR with good accuracy, with coefficient of determination (R2) values ranging from 0.94 to 0.99 and mean absolute error (MAE) values ranging from 0.30 to 0.51. In a novel approach, the genetic programming method was used to produce an equation to estimate CBR, which included seven inputs and accurately predicted CBR. The analysis of sensitivity and importance of parameters showed that the number of hammer blows for compaction was the most important parameter, while the parameters for maximum dry density of soil and mixture were the least important. This study suggests that AI methods can effectively predict the performance of alum sludge as a soil stabilizer, and the proposed equation using genetic programming can be a useful tool for predicting CBR.

To prolong the fatigue life of a product handled by machine, parametric accelerated life testing (ALT) is mentioned as an organized technique to pinpoint design flaws and minimize fatigue-connected failures. It requires (1) an ALT procedure, (2) fatigue model, (3) parametric ALTs with adjustment, and (4) an approximate of whether present product complete the BX life. The use of a quantum-transported time-to-failure archetype and a sample size are advised. The improvements in the reliability of a refrigerator ice-maker, comprising an auger motor with bearing, were utilized as a case investigation. In the 1st ALT, a steel rolling bearing cracked due to repeated loads under cold circumstances (below −20 C) in the freezer compartment. The bearing was altered by adjusting the matter from AISI 52100 alloy steel with 1.30-1.60% chromium to lubricated sliding bearing with sintered and hardened steel (FLC 4608-110HT) because of its high fatigue strength at lower temperatures. In the 2nd ALT, a helix made of polycarbonates (PCs) fractured. As an adjustment, a reinforced rib of the helix was thickened. As no troubles in the 3rd ALT occur, the lifetime of an ice-maker was proved to be B1 life 10 years.

In recent years, intelligent fault diagnosis algorithms using deep learning method have achieved much success. However, the signals collected by sensors contain a lot of noise, which will have a great impact on the accuracy of the diagnostic model. To address this problem, we propose a one-dimensional convolutional neural network with multi-scale kernels (MSK-1DCNN) and apply this method to bearing fault diagnosis. We use a multi-scale convolution structure to extract different fault features in the original signal, and use the ELU activation function instead of the ReLU function in the multi-scale convolution structure to improve the anti-noise ability of MSK-1DCNN; then we use the training set with pepper noise to train the network to suppress overfitting. We use the Western Reserve University bearing data to verify the effectiveness of the algorithm and compare it with other fault diagnosis algorithms. Experimental results show that the improvements we proposed have effectively improved the diagnosis performers of MSK-1DCNN under strong noise and the diagnosis accuracy is higher than other comparison algorithms.

Nitride and carbide are the second phases which play an important role in the performance of bearing steel, and their precipitation behavior is complicated. In this study, TiN-MC_x precipitations in GCr15 bearing steels were obtained by non-aqueous electrolysis, and their precipitation mechanisms were studied. TiN is the effective heterogeneous nucleation site for Fe₇C₃ and Fe₃C, therefore, MC_x can precipitate on the surface of TiN easily, its chemistry component consists of M₃C and M₇C₃ (M = Fe, Cr, Mn) and Cr₃C₂. TiN-MC_x with high TiN volume fraction, TiN forms in early stage of solidification, and MC_x precipitates on TiN surface after TiN engulfed by the solidification advancing front. TiN-MC_x with low TiN volume fraction, TiN and MC_x form in late stage of solidification, TiN can not grow sufficiently and is covered by a large number of precipitated MC_x particles.

The vibration signal of the engine contains strong background noise and many kinds of modulating components, which is difficult to diagnose. Variational mode decomposition (VMD) is a recently introduced adaptive signal decomposition algorithm with a solid theoretical foundation and good noise robustness compared with empirical mode decomposition (EMD). VMD can effectively avoid endpoint effect and modal aliasing. However, VMD cannot effectively eliminate the random noise in the signal, so the random decrement technique is introduced to solve the problem. Based on the crankshaft bearing fault simulation experiment, the four kinds of wear state vibration signals are decomposed by VMD, and the modal components with smaller permutation entropy are selected as fault components. Then the fault component is processed by the random decrement technique, and the Hilbert envelope spectrum of the fault component is obtained. Compared with the fault feature extraction method based on EMD and EEMD, the feature extraction results of the proposed method are better than those of the above two methods. The simulation analysis and the simulation test of the crankshaft bearing fault verify the effectiveness of the proposed method.

Plastic contamination of small dimensions (

The gold deposits of the eastern region of Cuba are genetically related to the lithological formations of the island arc and the ophiolitic complex, which have been studied and exploited since the time of the Spanish colonization in the mid-sixteenth century. These deposits are part of the so-called Aguas Claras-Guajabales mineral field, in the Holguín Province (Cuba) and lie in an extensive elongated strip of approximately 15 km in length. The object of this work is to make an orderly, detailed, and chronological review of the geological and mining work carried out in this region as well as to highlight the degree of study achieved in each of the stages of research. To facilitate this work, an extensive bibliographic review of all available materials was planned and carried out, such as reports, manuals, monographs, and articles. The results obtained from this study highlight that gold mineralization is closely linked to metasomatic processes produced by the circulation of hydrothermal fluids that affected different lithologies of both the volcanic island arc and the ophiolitic complex, it is noteworthy that the highest gold contents are mainly where the lithologies contact each other. This highlights the fact that the presence of alterations such as serpentinization, listvenitization, rodingitization and propylitization have played a primary role in the deposition of gold during mineralization processes. This work could be a very useful guide for future research in this region, as it is an orderly, concrete, and practical compilation of the characteristics of the mineralization and alterations, as well as a precise indication of the spatial position, thicknesses, and contents of the gold horizons.

The manuscript presents the optical properties of directly deposited films of gold nanoparticles (AuNPs) prepared by ultrasonic spray pyrolysis technology. Four samples were produced, with an AuNPs deposition time of 15 min, 30 min, 1h and 4h on the glass substrate. The morphological characterization of the deposited films showed that the size of the first deposited AuNPs is between 10 and 20 nm, while with a longer duration of the deposition process, larger clusters of AuNPs grow by coalescence and aggregation. The prepared layers were optically characterised with Ultraviolet–visible spectroscopy (UV-vis) and ellipsometry. The ellipsometric measurements showed an increasingly denser and thicker effective thickness of the AuNPs layers. The extinction spectra display a clear local surface plasmonic resonance (LSPR) signature (peak 520-540 nm), indicating the presence of isolated particles in all samples. For all AuNPs layers, the imaginary part of both ε// and ε⏊ is dominated by a central peak around 2.2 eV corresponding to the LSPR of isolated particles and a high-energy shoulder due to Au interband transitions. It is shown that, as the density of particles increases, the extinction cross section grows over the whole spectral range where measurements are taken. Thus response can be explained with an enhanced electromagnetic response among AuNPs, that can be connected to the increase of particle density but also by the formation of clusters and irregular structures.

MIPs inspired by antigen-antibody interactions have received substantial interest as a biomimetic artificial receptor system in environmental applications. Herein, we present a molecularly imprinted surface plasmon resonance (SPR) sensor integrated with Au nanoparticles for the identification of bisphenol A (BPA), an endocrine-disrupting chemical. The synthetic wastewater samples were analyzed to ensure the method's reliability and feasibility. Under ideal conditions, the suggested approach performed well in terms of analytical performance to BPA, with a wide linear range of 0.1 to 10 ppb and LOD of 10 ng/L. The sensor results and the Langmuir adsorption model have good agreement. It has also been shown that repeated use of the biosensor can be achieved. According to selectivity studies, BPA adsorbed within the imprinted cavities favorably compared to 4-nitrophenol and phenol. The produced BPA-imprinted SPR sensor provides improved sensitivity based on the signal amplification strategy, unconjugated sensing without the need for labeling, real-time sensing, low sample consumption rates, quantifiable assessment, and very good kinetic rate constant calculation in actual samples. Also, because the produced sensor is reusable with relative standard deviations (RSD)<1.25, indicating the sensor's accuracy, the SPR-based biomimetic BPA sensor is simple to practice and may be an economical option.

The utilization of gold nanoparticles (AuNPs) has garnered significant attention in recent times, particularly in the field of biomedical research. The utilization of AuNPs in chemical synthesis procedures raises apprehensions regarding their potential toxicity in living organisms, which is inconsistent with their purported eco-friendly and cost-effective aspects. In this investigation, AuNPs were synthesized via the green synthesis approach utilizing Jeju Hallabong peel extract (HPE), a typical fruit variety indigenous to South Korea. The visible-range absorption spectrum of gold nanoparticles from green synthesis (HAuNPs) that are red wine in color occurs at a wavelength of λ = 517 nm. The morphology and particle size distribution were analysed using transmission electron microscopy (TEM) and ImageJ software. The TEM images reveal that the HAuNPs exhibit a high degree of dispersion and uniformity in their spherical shape, with an average size of approximately 7 nm. Moreover, elevating the initial pH level of the mixed solution has an impact on the decrease in particle dimensions, as evidenced by the blue shift observed in the UV-visible spectroscopy absorbance peak. Elevating the reaction temperature may accelerate the synthesis duration. However, it does not exert a substantial impact on the particle dimensions. The outcomes of an avidin-biocytin colorimetric assay provide preliminary analyses of possible sensor tunability using HAuNPs. The cytotoxicity of HAuNPs was evaluated through in vitro studies using the MTT assay on RAW 264.7 cell lines. The results indicated that the HAuNPs exhibited lower cytotoxicity compared to both chemically reduced gold nanoparticles (CAuNPs) and commercially available gold nanoparticles (SAAuNPs).

Diabetic retinopathy (DR) and cataracts (CA) have an early onset in diabetes mellitus (DM) due to the redox imbalance and inflammation triggered by hyperglycemia. Plant-based therapies are characterized by low bioavailability in ocular tissues. The study aimed to investigate the effect of gold nanoparticles phytoreduced with Rutin (AuNPsR), as a possible solution. Insulin, Rutin, and AuNPsR, were administered to an early, six-week rat model of DR and CA. Oxidative stress (MDA, CAT, SOD) was assessed in serum and eye homogenates, and inflammatory cytokines (IL-1 beta, IL-6, TNF alpha) were quantified in ocular tissues. Fundus of retinal arterioles, retina histopathology and lens transmission electron microscopy (TEM), were also performed. DM was linked to constricted retinal arterioles, reduced endogen antioxidants, and eye inflammation. Histologically, retinal wall thickness decreased. TEM showed increased lens opacity and fiber disorganization. Rutin improved retinal arteriolar diameter, while reducing oxidative stress and inflammation. Retinas were moderately edematous. Lens structure was preserved on TEM. Insulin restored retinal arteriolar diameter, while increasing MDA, and amplifying TEM lens opacity. The best outcomes were obtained for AuNPsR, as it improved fundus appearance of retinal arterioles, decreased MDA formation and increased antioxidant capacity. Retinal edema and disorganization in lens fibers were still present.

Nanoparticles (NPs) have uniform chemical composition, size, and morphology. Microorganisms are of great interest in Nanoparticle synthesis. The green production of nanomaterials occurs either intracellularly or extracellularly. Gold and silver nanoparticles are mostly synthesised by the enzymatic degradation of metal ions. The produced NPs are characterized by different instruments such as ultraviolet visible, dynamic light scattering, x-ray diffraction, scanning electron microscope, transmission electron microscope, etc. Our review discusses the various biomedical applications of gold and silver nanoparticles synthesized by microbes via intracellular and extracellular mechanisms.

The Computational theoretical techniques using first principle which make use of the density functional theory as implemented by quantum expresso as well as inter – atomic force constant (IFC) techniques (Born-von Jarman) were used to investigate the phonon dispersion curves of Silver (Ag) and Gold (Au) The results obtained show that for Au, the extension to 1 – 6^th neighbour gave slightly close agreement with the experimental phonon dispersions when compared to the 1 – 5^th neighbor at W_T and L_L symmetry points. The percentage error for Au at W_T are 2.5% and 2.9% ; at point L_L we obtained 0.6% and 0.7% respectively. The Local density Approximation (LDA) results for Ag underestimates the lattice with about 1.6% while the Generalized Gradient Approximation (GGA) overestimates it by 1.9%.

Gold nanoparticles (AuNPs) are promising candidates in various biomedical applications such as sensors, imaging, and cancer therapy. Understanding the influence of AuNPs on lipid membranes is important to assure their safety in the biological environment and to improve their scope in nanomedicine. In this regard, the present study aims to analyze the effects of different concentrations (0.5, 1, and 2 w %) of dodecanethiol functionalized hydrophobic AuNPs on the structure and fluidity of zwitterionic 1-stearoyl-2-oleoyl-sn-glycerol-3-phosphocholine (SOPC) lipid bilayer membranes using Fourier transform infrared (FTIR) spectroscopy and fluorescent spectroscopy. The size of AuNPs was found to be 2.2 ± 1.1 nm using transmission electron microscopy. FTIR results have shown that the AuNPs induced a slight shift in methylene stretching bands, while the band positions of carbonyl and phosphate group stretching were unaffected. Temperature-dependent fluorescent anisotropy measurements have shown that the incorporation of AuNPs up to 2 w % did not affect the lipid order in membranes. Overall, these results indicate that the hydrophobic AuNPs in the studied concentration did not cause any significant alterations in the structure and membrane fluidity, which suggests the suitability of these particles to form liposome-AuNP hybrids for diverse biomedical applications including drug delivery and therapy.

The photocatalytic hydrogen evolution reaction (HER) by water splitting has been studied, using catalysts based on TiO2 nanowires (TiO2NWs), which were synthesized by a hydrothermal procedure. This nanomaterial was subsequently modified by incorporating different loadings of gold nanoparticles (AuNPs) on the surface, previously exfoliated MoS2 nanosheets, and CeO2 nanoparticles (CeO2NPs). These nanomaterials, as well as the different synthesized catalysts, were characterized by electron microscopy (HR-SEM and HR-TEM), XPS, XRD, Raman, Reflectance and BET surface area. HER studies were performed in aqueous solution, under irradiation at different wavelengths, which were selected through the appropriate use of optical filters. The results obtained show that there is a synergistic effect between the different nanomaterials of the catalysts. The specific area of the catalyst, and especially the increased loading of MoS2 and CeO2NPs in the catalyst substantially improved the H2 production. Recyclability studies showed only a decrease in activity of approx. 7% after 15 cycles of use, which opens many possibilities regarding the potential use and scaling of these heterostructures in photocatalytic production of H2 from water.

Modern technologies for recycling electronic waste (e-waste) impose high economic efficiency and environmental safety requirements. Among existing technologies, hydrometallurgy is considered the most promising technology for e-waste recycling. Increasing attention to the chlorination method is associated with the complex recycling of low-grade ores containing noble metals and secondary polymetallic raw materials. In this paper, we propose a new scheme for leaching metals from computer printed circuits (PCBs) pre-crushed in a disintegrator: the processes of chlorine production and hydrochlorination are implemented in one reactor under the action of alternating current (AC) of industrial frequency (50 Hz). It was found that complete leaching of gold is achieved from fine fractions of raw materials containing 0.03% and 0.01% of the gold at an experiment duration of 2 hours, a current density of 0.66 A·cm-2, and a solid/liquid ratio of 8.6 g·L-1. Under the same conditions of the electrochemical leaching process from the fraction of raw material with a gold content of 0.08%, the degree of metal leaching is 80.5%. At the same time, with an increase in the copper content in the raw material from 1.40% to 6.13%, an increase in the degree of its leaching from 84.6% to 95.2%, respectively, is observed. These results will serve as a foundation for developing a complex technology for recovering valuable metals from PCBs.

Accelerated degradation tests (ADT) are widely used in the manufacturing industry to obtain information on the reliability of components and materials, through degrading the lifespan of the product by applying an acceleration factor which causes damage to the material. The main objective is to obtain fast information which is modeled to estimate the characteristics of the material life under normal conditions of use and to save time and expenses. The purpose of this work is to estimate the lifespan distribution of gold nanoparticles stabilized with lipoic acid (GNPs@LA) through accelerated degradation tests applying sodium chloride (NaCl) as an acceleration factor. For this, the synthesis of GNPs@LA was carried out, a constant stress ADT (CSADT) was applied, and the non-linear Wiener process was proposed with random effects, error measures and different covariability for the adjustment of the degradation signals. The information obtained with the test and analysis allows us to obtain the life distribution in GNPs@LA, the results make possible to determine the guaranteed time for a possible commercialization and successful application based on the stability of the material. In addition, for the evaluation and selection of the model, the Akaike and Bootstraping criteria were used.

Gold nanoparticles have been indicated for use in a diagnostic and/or therapeutic role in several cancer types. The use of gold nanorods (AuNRs) with a surface plasmon resonance (SPR) in the second Near-Infrared II (NIR-II) optical window promises deeper anatomical penetration through increased maximum permissible exposure and lower optical attenuation. In this study, the targeting efficiency of anti-epidermal growth factor receptor (EGFR) antibody functionalised AuNRs with an SPR at 1064 nm was evaluated in vitro. Four cell lines, KYSE-30, CAL-27, Hep-G2 and MCF-7 that either over or under expressed EGFR were used. This expression was confirmed by flow cytometry and immunofluorescence. Cytotoxicity assays showed no AuNRs toxicity to both EGFR positive and EGFR negative cell lines up to a concentrations of 19 µg/ml. Optical microscopy demonstrated a significant difference (p&lt;0.0001) between targeted AuNRs (tAuNRs) and untargeted AuNRs (uAuNRs) in all four cancer cell lines. This study demonstrates that anti-EGFR functionalisation significantly increased the number of tAuNRs associated with each EGFR positive cancer cell. This successful targeting highlights the use of tAuNRs for molecular photoacoustic imaging or tumour treatment through plasmonic photothermal therapy.

A simple and rapid positive–negative colorimetric approach to determine the presence of antimony ions based on the use of gold nanoparticles conjugated with oligonucleotide (poly-A sequence) is developed. Colorimetric measurements reveal that the aggregates of modified gold nanoparticles were afforded after adding antimony ions, thus changing the solution color from pink to blue. The results of aptamer’s interaction on the gold nanoparticle surface with target analyte can be detected either by photometry or by the naked eye. The realized assay provides rapid (2 min), sensitive (detection limit 10 ng/mL), specific, and precise (variation coefficient less than 3.8%) detection of antimony (III) in drinking water

While deforestation rates decline globally they are rising in the Western Amazon. Artisanal-scale gold mining (ASGM) is a large cause of this deforestation and brings with it extensive environmental, social, governance, and public health impacts, including large carbon emissions and mercury pollution. Underlying ASGM is a broad network of factors that influence its growth, distribution, and practices such as poverty, flows of legal and illegal capital, conflicting governance, and global economic trends. Despite its central role in land use and land cover change in the Western Amazon and the severity of its social and environmental impacts, it is relatively poorly studied. While ASGM in Southeastern Peru has been quantified previously, doing so is difficult due to the heterogeneous nature of the resulting landscape. Using a novel approach to classify mining that relies on a fusion of CLASlite and the Global Forest Change dataset, two Landsat-based deforestation detection tools, we sought to quantify ASGM-caused deforestation in the period 1984–2017 in the southern Peruvian Amazon and examine trends in the geography, methods, and impacts of ASGM across that time. We identify nearly 100,000 ha of deforestation due to ASGM in the 34-year study period, an increase of 21% compared to previous estimates. Further, we find that 10% of that deforestation occurred in 2017, the highest annual amount of deforestation in the study period, with 53% occurring since 2011. Finally, we demonstrate that not all mining is created equal by examining key patterns and changes in ASGM activity and techniques through time and space. We discuss their connections with, and impacts on, socio-economic factors, such as land tenure, infrastructure, international markets, governance efforts, and social and environmental impacts.

A great improvement in food safety and quality controls worldwide has been achieved through the development of biosensing platforms. Foodborne pathogens continue to cause serious outbreaks due to the ingestion of contaminated food. The development of new, sensitive, portable, high-throughput, and automated platforms is a primary objective to allow detection of pathogens and their toxins in foods. Listeria monocytogenes is one common foodborne pathogen. Major outbreaks of listeriosis have been caused by a variety of foods, including milk, soft cheeses, meat, fermented sausages, poultry, seafood and vegetable products. Due to its high sensitivity and easy setup, electrochemical impedance spectroscopy (EIS) has been extensively applied for biosensor fabrication and in particular in the field of microbiology as a mean to detect and quantify foodborne bacteria. Here we describe a miniaturized, portable EIS platform consisting of a microfluidic device with EIS sensors for the detection of L. monocytogenes in milk samples, connected to a portable impedance analyzer for on-field application in clinical and food diagnostics but also for biosecurity purposes. To achieve this goal microelectrodes were functionalized with antibodies specific for L. monocytogenes. The binding and detection of L. monocytogenes was achieved in the range 2.2 x 103 cfu/ml to 1 x 102 with a Limit of Detection (LoD) of 5.5 cfu/ml.

The lectin found in the tubers of the Winter Aconite (Eranthis hyemalis) plant (EHL) is a Type II Ribosome Inactivating Protein (RIP); type II RIPs have shown anti-cancer properties, and have great potential as therapeutic agents. Similarly, colloidal gold nanoparticles are successfully used in biomedical applications as gold nanoparticles can be functionalised with ligands with high affinity and specificity for target cells to create therapeutic and imaging agents. Herein we present the synthesis and characterization of gold nanoparticles conjugated with EHL. The aim was to establish the viability of the conjugate and perform a set of initial assays to establish whether the biological effect of EHL is altered by the conjugation. The biological assays were performed in Caenorhabditis elegans, a free living nematode commonly used for toxicological studies; previous work from some of the authors using first life stage (L1) nematodes has shown that EHL has a strong biocidal effect on C. elegans. Gold nanoparticles functionalised with EHL (AuNPs@EHL) were successfully synthesised by bioconjugation with citrate gold nanoparticles (AuNPs@Citrate); the conjugates were analysed by UV-Vis spectroscopy, Dynamic Light Scattering (DLS), Zeta Potential analysis and Transmission Electron Microscopy (TEM). Results indicate that an optimal functionalisation was achieved with the addition of 100 µL of EHL (concentration 1090 ± 40 µg/mL) over 5 mL of AuNPs (concentration [Au0] = 0.8 mM). Biological assays on the effect of AuNPs@EHL on C. elegans were performed, using first life stage (L1) and pre-adult stage (L4) nematodes. Citrate gold nanoparticles did not have any obvious effect on the nematodes. For L1 stage nematodes, the assays show that conjugation with gold nanoparticles reduced the biological effect of EHL on C. elegans. As lectin binding activity is essential for the natural protein to bind and allow entry to cells, conformational changes due to conjugation may have affected this binding affinity. For L4 stage nematodes, both EHL alone and AuNPs@EHL showed biological activity, and reproductive delays and reduced fecundity were observed in both cases. These assays indicate that EHL can be conjugated to gold nanoparticles and retain elements of biocidal activity.

Tsygankoite, ideally Mn8Tl8Hg2(Sb21Pb2Tl)Σ24S48, is a new sulfosalt discovered at the Vorontsovskoe gold deposit, Northern Urals, Russia. It occurs as lath-like elongated crystals up to 0.2 mm embedded in calcite-dolomite-clinochlore matrix. The associating minerals also include aktashite, alabandite, arsenopyrite, barite, cinnabar, fluorapatite, orpiment, pyrite, realgar, routhierite, sphalerite, tilasite, titanite, etc. The new mineral is non-fluorescent, black, opaque with a metallic lustre and black streak. It is brittle with an uneven fracture and no obvious parting and cleavage. Its Vickers hardness (VHN10) is 144 kg/mm2 (range 131–167) and its calculated density is 5.450 g cm-3. In reflected light tsygankoite is white; between crossed polars it is dark-grey to black. It is strongly anisotropic: rotation tints vary from light-grey to dark-grey to black. Pleochroism and internal reflections are not observed. The chemical composition of tsygankoite (wt.%, electron-microprobe data) is: Mn 6.29, Fe 0.02, Cu 0.02, Ag 0.01, Hg 5.42, Tl 26.05, Pb 5.84, As 3.39, Sb 30.89, S 21.87, Se 0.01, total 99.81. The empirical formula, calculated on the basis of 90 atoms pfu, is: Mn8.06Tl8.00(Hg1.90Fe0.03Cu0.02Ag0.01)Σ1.96(Sb17.85As3.18Pb1.98Tl0.97)Σ23.98(S48.00Se0.01)Σ48.01. Tsygankoite is monoclinic, space group C2/m, a = 21.362(4) Å, b = 3.8579(10) Å, c = 27.135(4) Å, β= 106.944(14)°, V = 2139.19(17) Å3 and Z = 1. The five strongest diffraction peaks from X-ray powder pattern [listed as (d,Å(I)(hkl)] are: 3.587(100)(112), 3.353(70)(-114), 3.204(88)(405), 2.841(72)(-513) and 2.786(99)(-514). The crystal structure of tsygankoite was refined from single-crystal X-ray diffraction data to R = 0.0607 and consists of an alternation of two thick layer-like arrays, one based on PbS-archetype and second – on SnS-archetype. Tsygankoite has been approved by the IMA-CNMNC under the number 2017-088. It is named for Mikhail V. Tsyganko, mineral collector from Northern Urals, who collected the samples where the new mineral was discovered.

Gigantic particle accelerators, incredibly complex detectors, an antimatter factory and the discovery of the Higgs boson – this is part of what makes CERN famous. Only a few know that CERN also hosts the world largest Open Access initiative: SCOAP3. The Sponsoring Consortium for Open Access Publishing in Particle Physics (SCOAP3) started operation in 2014 and has since supported the publication of 19,000 Open Access articles in the field of particle physics, at no direct cost, nor burden, for individual authors worldwide. SCOAP3 is made possible by a 3,000-institute strong partnership, where libraries re-direct funds previously used for subscriptions to ’flip’ articles to ’gold Open Access’. With its recent expansion, the initiative now covers about 90% of the journal literature of the field. This article describes the economic principles of SCOAP3, the collaborative approach of the partnership, and finally summarizes financial results after four years of successful operation.

In the field of engineering, tracked vehicles play a significant role in accessing challenging terrains. Maintaining trafficability is of the utmost importance when it comes to tracked vehicles traversing rugged terrains; it provides stability, traction, and adaptability for a wide range of applications, including deep-sea exploration. The terrain characteristics pertain to the interactions that determine the mobility of tracked vehicles. Traditional Terramechanics models are in-adequate in depicting the correlation between tracks and soil. An important issue is the lack of consideration for the moisture content in the soil and the rate at which sinking occurs in these models. Examining sinkage speed helps describe the ability of tracked vehicles to move at high speeds. The focus is on the critical factors influencing the mobility of tracked vehicles, precisely the sinkage speed and its relationship with pressure. Experimental tests in a soil bin, utilizing Bentonite/Diatom sediment soil, aim to measure these terrain factors. The study introduces a rubber-tracked vehicle, pressure, and moisture sensors to monitor pressure sinkage and moisture, evaluating cohesive soils (Bentonite/Diatom) in combination with sand and gravel mixtures. Findings reveal that higher moisture content in Bentonite soil leads to increased track slippage and sinkage compared to Diatom soil. Regarding soil behavior, diatom soil exhibited notable compaction and sinkage characteristics in contrast to bentonite soil. The distinct behaviors of these soils underscore the complexity of terrains, emphasizing the need for a meticulous understanding of soil properties before applying them in natural environments. Furthermore, this study contributes precision in assessing natural terrains, enhancing tracked vehicle design, and advancing terrain mechanics comprehension for off-road exploration. This knowledge contributes to better vehicle design and a deeper comprehension of terrain mechanics.

Tracked vehicles play a vital role in accessing challenging terrains, offering stability, traction, and versatility for various applications, including deep-sea exploration. However, the seafloor and sediment contain valuable but poorly understood resources, making it a significant challenge for tracked vehicles during exploration. Consequently, it is imperative to conduct comprehensive studies before considering these terrains for off-road purposes. In this study, we developed a rigid, flexible track vehicle equipped with various sensors, focusing on monitoring pressure sinkage. Cohesive soils like Bentonite and Diatom soil, particularly when combined with sand and gravel mixtures, were used for the investigation and assessed for ground pressure, bearing capacity, and sinkage in rigid-flexible tracked vehicles on these characterized terrains under varying moisture conditions. Our findings indicated that increased moisture content in bentonite soil resulted in significantly higher track slippage and sinkage compared to diatomaceous earth soil. Regarding soil behavior, diatom soil exhibited notable compaction and sinkage characteristics compared to bentonite soil. These significant variations between these two soil types under changing moisture conditions highlight the complexity of such terrains. Therefore, understanding the soil and its physical properties is crucial before applying them to natural terrains. Furthermore, this study emphasizes the importance of precision in assessing the physical properties of natural terrains for the development of tracked vehicles for off-road exploration. This knowledge contributes to better vehicle design and a deeper comprehension of terrain mechanics.

In this study, three new demountable joints consisting of reinforced concrete columns and steel beams were proposed and their seismic performance was investigated using cyclic loading tests. The test results demonstrated that the three demountable RCS joints had good seismic performance. Using the finite element software ABAQUS, the influence of parameters such as beam flange thickness, bolt strength, and connector steel strength on the seismic performance of each joint was analyzed, and the influence of different parameters on the seismic behavior of the joint was determined. The results also showed that the three demountable RCS joints were sensitive to changes in the thickness of the steel beam flange, while the connector steel strength and bolt type had little impact on the joint's capacity. Additionally, shear capacity calculation formulas for the joint core area provided by different codes and researchers were compared with test and finite element results. The results showed that the calculation results of the ASCE guidance method, the Nishiyama method, and the CECS 347-2013 method were higher than the test values, while the calculation results of the Para method were lower because it did not consider the contribution of the cylindrical steel plate to the shear capacity of the joint core area.

Underwater acoustic spiral sources are able to generate spiral acoustic fields where the phase depends on the bearing angle. It allows to estimate the bearing angle relatively to a receiver by subtracting the phases of a spiral and a circular wavefront, and finds application in the bearing angle estimate with a single hydrophone, e.g., for unmanned underwater vehicles localization. This paper presents a new prototype for a spiral acoustic source, which is able to generate the required wavefronts, and is composed of four monopoles in the same piezoceramic cylinder. This paper reports the prototyping and the acoustic tests performed in a water tank where the spiral source was characterized in terms o Transmitting Voltage Response, phase, and horizontal and vertical directivity patterns. A receiving calibration method for the spiral source is proposed and shows a maximum angle error of 1 degree when the calibration and the operation are carried under the same conditions and a mean angle error up to 6 degrees for frequencies above 25 kHz when the same conditions are not fulfilled.

The diagnosis of a rolling bearing for monitoring its status is critical for maintaining industrial equipment using rolling bearings. The traditional method of diagnosing faults of the rolling bearing has low identification accuracy, which needs artificial feature extraction to enhance the accuracy. 1D-CNN method not only can diagnose bearing faults accurately but also overcome shortcomings of the traditional methods. Different from machine learning and other deep learning models, the 1D-CNN method does not need pre-processing one-dimensional data of rolling bearing’s vibration. Thus, it enhances the processing speed and improves the network structure to have a reasonable design for small sample data sets. This study proposes and tests a 1D-CNN method for diagnosing rolling bearings. By introducing the dropout operation, the method obtains high accuracy and improves the generalizing ability. The experimental results show 99.52% of the average accuracy under a single load and 98.26% under different loads.

In this paper, we introduce the Prognostics and Health Management of gear bearing system using autoencoder neural networks. Bearings and gears are the most common mechanical components in rotating machines, and their health conditions are of great concern in practice. This study presents an outlier modeling method for forecasting the gear bearing system failure using the health indicators constructed from mechanical signal processing and modeling. Outlier modeling aims to find patterns in data that are significantly different from what is defined as normal. In the unsupervised outlier modeling setting, prior labels about the anomalousness of data points are not available. In such cases, the most common techniques for scoring data points for outlyingness include distance-based methods density-based methods, and linear methods. The conventional outlier modeling methods have been used for a long time to detect anomalous observations in data. However, this paper shows that autoencoders are a very competitive technique compared to other existing methods. The developed method is demonstrated using the IMS bearing data from NASA Acoustics and Vibration Database.

In this study we used a non-autonomous Chua’s Circuit, and the fractional Lorenz chaos system together with a detection method from Extension theory to analyze the voltage signals. The measured bearing signals by acceleration sensor were introduced into the master and slave systems through a Chua’s Circuit. In a chaotic system minor differences can cause significant changes that generate dynamic errors, and extension matter-element models can be used to judge the bearing conditions. Extension theory can be used to establish classical and sectional domains using the dynamic errors of the fault conditions. The results obtained were compared with those from Discrete Fourier Transform analysis, Wavelet analysis and an integer order chaos system. The diagnostic ratio showed the fractional order master and slave chaos system calculations. The results show that the method presented in this paper is very suitable for monitoring the operational state of ball bearing system to be superior to the other methods. The diagnosis ratio was better and there were other significant advantages such as low cost and few.

Electronic waste (e-waste), characterized by the widespread disposal of electronic devices, shows a growing environmental challenge. In this study, we explore the electrocatalytic potential of gold nanoparticles supported on Vulcan obtained from e-waste for their application as electrocatalysts for the methanol oxidation reaction in alkaline media. Gold nanoparticles are synthesized from gold coatings recovered from Intel Pentium 4 processor pins, highlighting their sustainability as electrocatalyst precursors. Comprehensive characterization, including UV-Vis spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray dif-fraction, is performed to assess the electrocatalyst's structural properties. Electrochemical evalu-ation is carried out in 0.5 M KOH electrolyte employing the rotating disk electrode technique, us-ing cyclic voltammetry for the study of methanol oxidation. Remarkably, the gold nanoparticles show electrocatalytic activity on par with commercially synthesized counterparts, demonstrating the feasibility of this approach for sustainable electrocatalyst production. Thus, this research opens new routes for utilizing e-waste as a source of valuable catalyst materials, addressing en-vironmental and technological challenges in the field of alkaline fuel cells.

In this work, a colorimetric indicator based on gold nanoparticles (AuNP) and a biodegradable and eco-friendly polymer (sodium alginate, Alg.), has been developed, for the real-time detection of fish spoilage products. AuNP and colorimetric indicator were characterized by: UV-Vis, FTIR spectroscopies, TGA, DSC, XRD, TEM, and colorimetry. The UV-Vis spectrum and TEM showed the successful synthesis, the spherical shape, and the size of AuNPs. Results indicated color changes of the indicator in packaged fish on day 9 of storage at refrigerated temperature (5ºC). These results showed the successful application of colorimetric indicator in the detection of TVB-N in packaged fish.

This study investigates the relationship between energy metals and precious metals to assess their suitability as safe haven assets in clean energy investment portfolios. It focuses on the impact of events in 2020 and 2022, characterized by substantial investments in clean energy. The research reveals that, except for Nickel Futures (NICKELc1), energy metals are positively linked with clean energy indexes. This suggests that they can serve as a secure investment option for green investors looking to diversify their portfolios. As a result, the study dismisses the initial question, indicating that energy metals can indeed be considered safe havens within the context of clean energy investments. Additionally, the research reinforces prior findings that precious metals like gold, silver, and platinum possess safe haven characteristics in relation to specific clean energy stock indexes. These results have significant implications, particularly given the increasing investments in clean energy stocks and the recurring uncertainties in the market. In summary, this study supports the idea that both energy metals and precious metals can play valuable roles in clean energy portfolios, providing stability during turbulent times in the market.