ARTICLE | doi:10.20944/preprints201806.0002.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: support vector machine; classification analysis; power transformer condition assessment; oil immersed paper insulation; dga; dielectric characteristics, furanic compounds
Online: 1 June 2018 (05:58:18 CEST)
Oil immersed paper insulation condition is a crucial aspect of power transformer’s life condition diagnostic. The measurement testing database collected over the years made it possible for researchers to implement classification analysis to in-service power transformer. This article presents classification analysis of transformer oil-immersed paper insulation condition. The measurements data (dielectric characteristics, dissolved gas analysis, and furanic compounds) of 149 transformers with primary voltage of 150 kV had been gathered and analyzed. The algorithm used for developing classification model is Support Vector Machine (SVM). The model has been trained and tested using different datasets. Different models have been created and the best chosen, resulting in 90.63% accuracy in predicting the oil-immersed paper insulation condition. Further implementation was executed to classify oil-paper condition of 19 Transformers which Furan data is not available. The classification results combined, reviewed, and compared to conventional assessment methods and standards, confirming that the model developed has the ability to do classification of current oil-paper condition based on Dissolved Gasses and Dielectric Characteristics.
ARTICLE | doi:10.20944/preprints201801.0122.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: hot spot temperature; transformer oil-paper insulating system; reliability assessment; dynamic correction; dissolved gas analysis; grey target theory
Online: 15 January 2018 (09:09:34 CET)
This paper develops a novel dynamic correction method for the reliability assessment of large oil-immersed power transformers. First, with the transformer oil-paper insulation system (TOPIS) as the target of evaluation and the winding hot spot temperature (HST) as the core point, an HST-based static ageing failure model is built according to the Weibull distribution and Arrhenius reaction law, in order to describe the transformer ageing process and calculate the winding HST for obtaining the failure rate and life expectancy of TOPIS. A grey target theory based dynamic correction model is then developed, combined with the data of Dissolved Gas Analysis (DGA) in power transformer oil, in order to dynamically modify the life expectancy calculated by the built static model, such that the corresponding relationship between the state grade and life expectancy correction coefficient of TOPIS can be built. Furthermore, the life expectancy loss recovery factor is introduced to correct the life expectancy of TOPIS again. Lastly, a practical case study of an operating transformer has been undertaken, in which the failure rate curve after introducing dynamic corrections can be obtained for the reliability assessment of this transformer. The curve shows a better ability of tracking the actual reliability level of transformer, thus verifying the validity of the proposed method and providing a new way for transformer reliability assessment. This contribution presents a novel model for the reliability assessment of TOPIS, in which the DGA data, as a source of information for the dynamic correction, is processed based on the grey target theory, thus the internal faults of power transformer can be diagnosed accurately as well as its life expectancy updated in time, ensuring that the dynamic assessment values can commendably track and reflect the actual operation state of the power transformers.
ARTICLE | doi:10.20944/preprints201704.0131.v1
Subject: Materials Science, Polymers & Plastics Keywords: polyurethane foams; castor oil; crude glycerol; biopolyols
Online: 20 April 2017 (04:27:10 CEST)
Rigid polyurethane foams were synthesized using a renewable polyol from the simple physical mixture of castor oil and crude glycerol. The effect of the catalyst and blowing agent in the foams properties was evaluated. The use of physical blowing agent (cyclopentane and n-pentane) allowed obtaining foams with smaller cells in comparison with the foams produced with a chemical blowing agent (water). The increase of water content caused a decrease of density, thermal conductivity, compressive strength and Young's modulus, which indicates that the increment of CO2 production contributes to the formation of larger cells. Higher amount of catalyst in the foam formulations caused a slight density decrease and an increase small significance of thermal conductivity, compressive strength and Young's modulus values. These green foams presented properties that indicate a great potential to be used as thermal insulation, as density (23 - 41 kg m-3), thermal conductivity (0.0128 – 0.0207 W m-1 K-1), compressive strength (45 - 188 kPa) and Young's modulus (3 - 28 kPa). These biofoams are also environmental friendly alternatives and can aggregate revenue to biodiesel industry, contributing for reduction of this fuel prices.
Subject: Engineering, Automotive Engineering Keywords: oil-paper insulation; drying of the transformer; synthetic ester
Online: 22 February 2021 (11:17:04 CET)
The research results presented in the article were carried out during the realization of the project, the aim of which is to develop a method of drying cellulose insulation in power transformers with the use of synthetic ester. This method uses a very high water absorption of the ester. During the drying of transformers, the ester is systematically contaminated with mineral oil, which gradually loses its ability to absorb water. Information on the oil concentration in the mixture is needed in two cases: at the stage of making a decision on the treatment of the mixture and during its treatment. The article presents the results of investigations of two methods: 1) based on the measurement of the mixture density, and 2) based on the measurement of the capacitance of the capacitor immersed in the mixture. The conducted research shows that the method of measuring the density of the mixture gives an uncertainty of 2.6 p. %, while the method of measuring the capacitance of a capacitor gives an uncertainty of 2.2 p. %. A significant advantage of the method of measuring the capacitance is the possibility of using it online to control the ester treatment process.
ARTICLE | doi:10.20944/preprints201912.0201.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Debye model; dielectric properties; power transformers; spectroscopy; recovery voltage measurement (RVM); oil-paper insulation
Online: 15 December 2019 (16:09:57 CET)
The aim of this document is to present how the interpretation of the RVM (Recovery Voltage Measurement) test can be improved through the use of a Debye equivalent circuit. As it is described in the literature the interpretation of the RVM test requires expertise and if the transformer presents a high interfacial polarization it is not possible to diagnose it in detail. Debye model is proposed in this work for enhancing RVM interpretation. This model is based on an electrical circuit that includes basic R-L-C components, that allows two interesting features: on one hand, isolation physical effects can be separately represented and, on the other, the values of the R-C components can be calculated from the RVM response (L components are not used in this work as long as no magnetic field effects are taken into account). Thus, the different isolation effects that are indistinguishable merged in the RVM transient response can be split into different R-C branches, each one corresponding with a single (not merged) isolation effect. Finally, several case studies are presented, in which it is correlated a dielectric oil treatment carried out and the equivalent circuit changes.
ARTICLE | doi:10.20944/preprints201912.0051.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: industrial informatics; automation; machine learning; paper grammage classification; paper mills
Online: 4 December 2019 (12:26:15 CET)
Automation is at the core of modern industry. It aims to increase production rates, decrease production costs, and reduce human intervention in order to avoid human mistakes and time delays during manufacturing. On the other hand, human assistance is usually required to customize products and reconfigure control systems through a special process interface called Human Machine Interface (HMI). Machine Learning (ML) algorithms can effectively be used to resolve this tradeoff between full automation and human assistance. This paper provides an example of the industrial application of ML algorithms to help human operators save their mental effort and avoid time delays and unintended mistakes for the sake of high production rates. Based on real-time sensor measurements, several ML algorithms have been tried to classify paper rolls according to paper grammage in a white paper mill. The performance evaluation shows that the AdaBoost algorithm is the best ML algorithm for this application with classification accuracy (CA), precision, and recall of 97.1%. The generalization of the proposed approach for achieving a cost-effective mill construction by reducing the total number of the required physical sensors will be the subject of our future research.
Subject: Materials Science, Nanotechnology Keywords: MoS2; paper electronics; optoelectronics; photodetector
Online: 25 June 2020 (16:16:19 CEST)
We fabricate paper-supported semiconducting devices by rubbing a layered molybdenum disulfide (MoS2) crystal onto a piece of paper, similarly to the action of drawing/writing with a pencil on paper. We show that the abrasion between the MoS2 crystal and the paper substrate efficiently exfoliates the crystals, breaking the weak van der Waals interlayer bonds and leading to the deposition of a film of interconnected MoS2 platelets. Employing this simple method, that can be easily extended to other 2D materials, we fabricate MoS2-on-paper broadband photodectectors with spectral sensitivity from the ultraviolet (UV) to the near-infrared (NIR). We also used these paper-based photodetectors to acquire pictures of objects by mounting the photodetectors in a homebuilt single-pixel camera setup.
ARTICLE | doi:10.20944/preprints201910.0288.v1
Subject: Chemistry, Other Keywords: diaminostilbene disulfonic acid; paper and paper mill; textile wastewater; fluorescent whitening agents; ozone oxidation
Online: 25 October 2019 (11:36:50 CEST)
In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that cannot be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor (MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbene disulfonic acid derivative by ozone oxidation were evaluated by UV254 Scan, COD, T-N and color using a synthetic wastewater sample (COD=433.0 mg/ℓ) and paper and paper mill wastewater (COD=157.2 mg/ℓ).
ARTICLE | doi:10.20944/preprints202112.0046.v1
Subject: Chemistry, Analytical Chemistry Keywords: Paperfluidics; Parafilm; Paper-based Analytical Devices
Online: 3 December 2021 (09:58:36 CET)
Paper-based analytical devices have been substantially developed in recent decades. Many fabrication techniques for paper-based analytical devices have been demonstrated and reported. Herein we report a relatively rapid, simple, and inexpensive method for fabricating paper-based analytical devices using parafilm hot pressing. We studied and optimized the effect of the key fabrication parameters, namely pressure, temperature, and pressing time. We discerned the optimal conditions, including pressure of 3.8 MPa (3 tons), temperature of 80oC, and 3 minutes of pressing time, with the smallest hydrophobic barrier size (821 µm) being governed by laminate mask and parafilm dispersal from pressure and heat. Physical and biochemical properties were evaluated to substantiate the paper functionality for analytical devices. Wicking speed in the fabricated paper strips was slightly slower than that of non-processed paper, resulting from reducing paper pore size. A colorimetric immunological assay was performed to demonstrate the protein binding capacity of the paper-based device after exposure to pressure and heat from the fabrication. Moreover, mixing in two-dimensional paper-based device and flowing in a three-dimensional counterpart were thoroughly investigated, demonstrating that the paper device from this fabrication process is potentially applicable as analytical devices for biomolecule detection. Fast, easy, and inexpensive parafilm hot press fabrication presents an opportunity for researchers to develop paper-based analytical devices in resource-limited environments.
ARTICLE | doi:10.20944/preprints202105.0478.v1
Subject: Engineering, Automotive Engineering Keywords: biopolymers; paper packaging; antimicrobial activity; nanoparticles
Online: 20 May 2021 (10:30:46 CEST)
Here, we designed the composition of the coating of the paper sheets composed of chitosan, bacterial cellulose (nanofibres), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following ASTM E2149-13a standard. Mechanical properties of the paper sheets were measured by comparison of tearing resistance, tensile strength, and bursting strength according to ISO 5270 standard. The increased antibacterial response is assigned to the combination of chitosan and ZnO (independently of its shape and size), while the boosted mechanical behavior is due to bacterial cellulose nanofibers. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.
ARTICLE | doi:10.20944/preprints202103.0307.v1
Online: 11 March 2021 (10:51:18 CET)
Usually in the manufacture of beer by fermentation of barley, in both industrialized and developing countries significant amounts of organic solid waste are produced from barley straw. These possibly have an impact on the carbon footprint with an effect on global warming. According to this, it is important to reduce environmental impact of these solid residues, and an adequate way is the recycling using them as raw material for the elaboration of handmade paper. Therefore, it is required to manage this type of waste by analyzing the environmental impact, and thus be able to identify sustainable practices for the treatment of this food waste, evaluating its life cycle, which is a useful methodology to estimate said environmental impacts. It is because of this work shows the main results obtained using the life cycle analysis (LCA) methodology, to evaluate the possible environmental impacts during the waste treatment of a brewery located in the state of Hidalgo, Mexico. The residues evaluated were barley straw, malt residues and spent grain, and at the end, barley straw was selected to determine in detail its environmental impact and its reuse, the sheets analyzed presented a grammage that varies from 66 g/m2 and 143 g/m2, resistance to burst was 117 to 145 kpa, with a crystallinity of 34.4% to 37.1%.
ARTICLE | doi:10.20944/preprints201911.0100.v1
Online: 10 November 2019 (09:24:22 CET)
Paper recycling has increased in recent years. A principal consequence of this process is the problem of addressing polymeric components known as stickies. A deep characterization of stickies sampled over one year in a recycled paper industry in México was performed. Based on their chemical structure, an enzymatic assay was performed using lipases. Compounds found in stickies by Fourier-Transform Infrared spectrometry were poly (butyl-acrylate), dioctyl phthalate, poly (vinyl-acetate), and poly (vinyl-acrylate). Pulp with 4% consistency and pH=6.2 was sampled directly from the mill once macro stickies were removed. Stickies were quantified by counting the tacky macrostructures in the liquid fraction of the pulp using a Neubauer chamber before the paper was made, and they were analyzed with rhodamine dye and a UV lamp. Of the two enzymes evaluated, the best treatment condition used Lipase 30G at a concentration of 0.44 g/L, which produced a 35.59% decrease in stickies. SebOil DG showed a smaller stickies reduction of 21.5% when used at a concentration of 0.33 g/L. Stickies in kraft paper processes were actively controlled by the action of lipases, and future research should focus on how this enzyme recognizes its substrate and should apply synthetic biology to improve lipase specificity.
ARTICLE | doi:10.20944/preprints201611.0038.v1
Subject: Materials Science, Biomaterials Keywords: polyhydroxybutyrate; nanofibrillated cellulose; paper coating; hydrophobicity
Online: 7 November 2016 (06:59:27 CET)
This study reports on the development of bio-based hydrophobic coatings for packaging papers through deposition of polyhydroxybutyrate (PHB) particles in combination with nanofibrillated cellulose (NFC) and plant wax. In a first approach, PHB particles in micrometer range (PHB-MP) were prepared through a phase-separation technique providing internally nanosized structures. The particles were transferred as a coating by dip-coating filter papers in the particle suspension, followed by sizing with a carnauba wax solution. This approach allowed partial to almost full surface coverage of PHB-MP over the paper surface resulting in static water contact angles of 105° to 122° and 129° to 144° after additional wax coating. In a second approach, PHB particles with submicron sizes (PHB-SP) were synthesized by an oil-in-emulsion (o/w) solvent evaporation method, and mixed in aqueous suspensions with 0 to 7 wt% NFC. After dip-coating filter papers in PHB-SP/NFC suspensions and sizing with a carnauba wax solution, static water contact angles of 112° to 152° were obtained. The intrinsic properties of the particles were analyzed by scanning electron microscopy, thermal analysis and infrared spectroscopy, indicating higher crystallinity for PHB-SP than PHB-MP. The chemical interactions between the more amorphous PHB-MP particles and paper fibers were identified as an esterification reaction, while the morphology of the NFC fibrillar network was playing a key role as binding agent in the retention of more crystalline PHB-SP at the paper surface, hence contributing to higher hydrophobicity.
ARTICLE | doi:10.20944/preprints202209.0446.v1
Subject: Social Sciences, Organizational Economics & Management Keywords: petroleum; oil market; oil; statistics
Online: 28 September 2022 (15:35:31 CEST)
The energy matrix worldwide has been going through difficulties in its discussions - such as irregular exploration, inefficient public policies, and arbitrariness concerning diplomatic and political definitions of those involved in this market. This work's general objective consists in analyzing associations and statistical inferences of the largest world oil producers, assimilating the contributions and singularities of this market from 1993 to 2020. Based on the Organization of the Petroleum Exporting Countries (OPEC), it was possible to identify the possible inferences and contributions of the ten largest oil producers in the world in more than two decades using statistical analysis through correlation, regression, and statistical analysis of variables. According to the research and the literature on the area, the oil market proposes support to its discussions, mainly in its productive approaches. It is possible to identify this market as a solid link to geopolitical actions, distributing the possibilities through economic bias and socio-cultural and historical factors on a global level.
ARTICLE | doi:10.20944/preprints202004.0185.v1
Subject: Materials Science, General Materials Science Keywords: paper core; impregnation; elastic properties; experiment; FEM
Online: 12 April 2020 (08:28:02 CEST)
The research hypothesis states that the impregnation of the honeycomb paper core of lightweight sandwich panels with modified starch, sodium silicate and LiquidWood® resin has a significant effect on the elastic properties of it. In the study, a recycled paper was used in three thicknesses, seven types of cell shapes, including two after numerical optimization and three types of impregnating agents. The method of digital image analysis determined the elastic constants of manufactured paper cores, which were subjected to axial compression in two directions. Based on the experimental results, elastic constants of the cores were calculated and compared with the results of numerical calculations. It has been shown that each of the impregnating solutions used improves the stiffness of the paper core. The best results were obtained for LiquidWood® epoxy resin and modified starch. An important parameter of cell geometry affecting their rigidity is the angle of the cell wall φ, as well as the arrangement of the common cell wall in relation to the direction of load. The numerical models developed were positively verified.
ARTICLE | doi:10.20944/preprints202002.0441.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: Paper based sensor; whole virus; Zika; Aptamer
Online: 28 February 2020 (13:30:18 CET)
Paper-based sensors, microfluidic platforms and electronic devices have attracted attention in the past couple of decades because they are flexible, can be recycled easily, environmentally friendly, and inexpensive. Here we report a paper aptamer-based potentiometric sensor to detect the whole Zika virus for the first time with a minimum sensitivity of 2.6 nV/Zika and the minimum detectable signal (MDS) of 0.8x1e6 Zika. Our paper sensor works very similar to a P-N junction where a junction is formed between two different wet regions with different electrochemical potentials near each other on the paper. These two regions with slightly different ionic contents, ionic species and concentrations, produce a potential difference given by the Nernst equation. Our paper sensor consisted of a 2-3 mm x 10 mm segments of a paper with a conducting silver paint contact patches on its two ends. The paper is soaked in a buffer solution containing aptamers designed to bind to the capsid proteins on Zika. Atomic force microscopy studies were carried out to show both the aptamer and Zika become immobilized in the paper. We then added the Zika (in its own buffer or simulant Urine) to the region close to one of the silver-paint contacts. The Zika virus (40 nm diameter with 43 kDa or 7.1x10-20 gm weight), became immobilized in the paper’s pores and bonded with the resident aptamers creating a concentration gradient. The potential measured between the two silver paint contacts reproducibly became more negative as upon adding the Zika. We also showed that an LCD powered by the sensor, can be used to detect the sensor output.
ARTICLE | doi:10.20944/preprints202002.0291.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: paper based sensor; whole virus; Zika; aptamer
Online: 20 February 2020 (07:24:39 CET)
Paper-based sensors, microfluidic platforms and electronic devices have attracted attention in the past couple of decades because they are flexible, can be recycled easily, environmentally friendly, and inexpensive. Here we report a paper aptamer-based potentiometric sensor to detect the whole Zika virus for the first time with a minimum sensitivity of 2.6 nV/Zika and the minimum detectable signal (MDS) of 1.2x106 Zika. Our paper sensor works very similar to a P-N junction where a junction is formed between two different wet regions with different electrochemical potentials near each other on the paper. These two regions with slightly different ionic contents, ionic species and concentrations, produce a potential difference given by the Nernst equation. Our paper sensor consisted of a 2-3 mm x 10 mm segments of a paper with a conducting silver paint contact patches on its two ends. The paper is soaked in a buffer solution containing aptamers designed to bind to the capsid proteins on Zika. Atomic force microscopy studies were carried out to show both the aptamer and Zika become immobilized in the paper. We then added the Zika (in its own buffer) to the region close to one of the silver-paint contacts. The Zika virus (40 nm diameter with 43 kDa or 7.1x10-20 gm weight), became immobilized in the paper’s pores and bonded with the resident aptamers creating a concentration gradient. The potential measured between the two silver paint contacts reproducibly became more negative as upon adding the Zika. We also showed that an LCD powered by the sensor, can be used to detect the sensor output.
ARTICLE | doi:10.20944/preprints201909.0299.v1
Online: 26 September 2019 (11:53:23 CEST)
This letter solves an open question of paper spring risen by Yoneda (2019). Universal scaling laws of a paper spring are proposed by using both dimensional analysis and data fitting. It is found that spring force obeys power square law of spring extension, however strong nonlinear to the total twist angle. Without doing any additional works, we have successfully generalize the scaling laws for Poisson ratio 0.3 to the materials with an arbitrary Poisson's ratio with the help of dimensional analysis.
ARTICLE | doi:10.20944/preprints202204.0083.v1
Subject: Life Sciences, Other Keywords: olive oil; sunflower oil; spicy olive oil; canned eel; colour; sensory analysis
Online: 9 April 2022 (01:36:15 CEST)
The different vegetable oils used in canned fish as filling medium have a preserving effect and contribute to the palatability of the product. In this study, the colour of European eels and the filling medium (sunflower oil, olive oil or spicy olive oil) was measured at different steps of the canning process. The sensorial characteristics of canned eels packed in the different oils were also evaluated. Colour scores (CieLab values) were higher in canned eels packed in sunflower and spicy olive oil than in canned eels packed in olive oil. The changes in colour parameters depended on the type of oil, the stage of the process and the storage time. Colour changes in canned eels packed in olive oil were highest during the sterilization process. Spicy olive oil was the filling medium in which the colour change was greatest, probably due to the migration of some of the spice components into the oil. Organoleptic properties were directly related to the type of oil used as the filling medium. The canned eels packed in sunflower oil were those awarded the highest scores in consumer tests, although the preferences varied depending on the age and gender of the consumers.
ARTICLE | doi:10.20944/preprints201906.0283.v1
Subject: Chemistry, Chemical Engineering Keywords: TEM; thermal degradation; wall paper; blowing agent; foam
Online: 27 June 2019 (06:29:11 CEST)
This study was conducted to improve the white index (WI) by preparing thermally expandable microspheres (TEMs) for wallpaper. The thermal properties, foam expansion ratio and WI were studied depending on the particle size of colloidal silica in the preparation of TEMs. As a result, the TEMs with small particles of colloidal silica showed the best results for whiteness and yellowing. Additionally, TGA results indicated that it was highly possible that colloidal silica with small particle sizes was physically or chemically attached to the surface of the TEMs that led to an improvement in whiteness at high temperatures.
ARTICLE | doi:10.20944/preprints202107.0363.v1
Subject: Life Sciences, Other Keywords: omega-3; omega-6; fatty acids; camelina oil, flaxseed oil; canola oil; canine nutrition
Online: 15 July 2021 (18:17:06 CEST)
This study aimed to determine whether camelina oil is safe for use in canine diets, using canola oil and flax oil as controls as they are similar and generally regarded as safe (GRAS) for canine diets. Thirty privately-owned adult dogs of various breeds (17 females; 13 males), with an average age of 7.2 ± 3.1 years (mean ± SD) and body weight (BW) of 27.4 ± 14.0 were used. After a 4-week wash-in period using sunflower oil and kibble, dogs were blocked by breed, age, and size, and randomly allocated to one of three treatment oils (camelina (CAM), flax (FLX), or canola (OLA)) at a level of 8.2 g oil/100g total dietary intake. Body condition score (BCS), BW, food intake (FI), and hematological and select biochemical parameters were measured at various timepoints over a 16-week feeding period. All data were analyzed with ANOVA using PROC GLIMMIX of SAS. No biologically significant differences were seen between treatment groups for BW, BCS, FI, hematological and biochemical results. Statistically significant differences noted among some serum biochemical results were considered small and due to normal biological variation. These results support a conclusion that camelina oil is safe for use in canine nutrition.
ARTICLE | doi:10.20944/preprints202107.0181.v1
Subject: Chemistry, Analytical Chemistry Keywords: SARS-CoV-2 detection; Immunofluorescence; Paper-based diagnostic device
Online: 7 July 2021 (13:18:33 CEST)
We report on an immunofluorescent paper-based assay for the detection of severe acute respiratory symptom coronavirus 2 (SARS-CoV-2) humanized antibody. The paper-based device was fabricated by using lamination technique for easy and optimized handling. Our approach utilises a two-step strategy that involves (i) initial coating of the paper-electrode with recombinant SARS-CoV-2 nucleocapsid antigen to capture the target SARS-CoV-2 specific antibodies, and (ii) subsequent detection of SARS-CoV-2 antibodies using fluorophore-conjugated IgG antibody. The fluorescence readout was observed with fluorescence microscopy. The images were processed and quantified using a MATLAB program. The assay can selectively detect SARS-CoV-2 humanized antibodies spiked in PBS and healthy human serum samples with the relative standard deviation of approximately 6.4% (for n = 3). It has broad dynamic ranges (1 ng to 50 ng/µL in PBS and 5 to 100 ng/µL in human serum samples) for SARS-CoV-2 humanized antibodies with the detection limits of 2 ng/µL (0.025 IU/mL) and 10 ng/µL (0.125 IU/mL) in PBS and human serum samples, respectively. We believe that our assay has the potential to be used as a simple, rapid, and inexpensive paper-based diagnostic device with a portable fluorescent reader to provide point-of-care diagnosis. This assay can be used for rapid examination of a large batch of samples toward clinical screening of SARS-CoV-2 specific antibodies as a confirmed infected active case or to evaluate the immune response to a SARS-CoV-2 vaccine.
ARTICLE | doi:10.20944/preprints202010.0506.v1
Subject: Chemistry, Analytical Chemistry Keywords: Paper-based microfluidic device; colorimetric; multiple detection; smartphone application
Online: 26 October 2020 (08:56:58 CET)
Paper-based microfluidic analysis devices (μPADs) have attracted attention as a cost-effective platform for point-of-care testing (POCT), food safety, and environmental monitoring. Recently, three-dimensional (3D)-μPADs have been developed to improve the performance of μPADs. For accurate diagnosis of diseases, however, 3D-μPADs need to be developed to simultaneously detect multiple biomarkers. Here, we report a 3D-μPADs platform for the detection of multiple biomarkers that can be analyzed and diagnosed with a smartphone. The 3D-μPADs were fabricated using a 3D digital light processing printer and consisted of a sample reservoir (300 µL) connected to 24 detection zones (of 4 mm in diameter) through 8 microchannels (of 2 mm in width). With the smartphone application, eight different biomarkers related to various diseases were detectable in concentrations ranging from normal to abnormal conditions: glucose (0–20 mmol/L), cholesterol (0–10 mmol/L), albumin (0–7 g/dL), alkaline phosphatase (0–800 U/L), creatinine (0–500 µmol/L), aspartate aminotransferase (0–800 U/L), alanine aminotransferase (0–1000 U/L), and urea nitrogen (0–7.2 mmol/L). These results suggest that 3D-µPADs can be used as a POCT platform for simultaneous detection of multiple biomarkers.
CONCEPT PAPER | doi:10.20944/preprints202212.0121.v1
Subject: Engineering, Other Keywords: palm oil industry; palm oil milling; process safety; leadership; culture
Online: 7 December 2022 (08:58:35 CET)
Several studies have highlighted the importance and evolution of process safety leadership and culture in various industries. However, none has focused on the palm oil milling industry yet. This paper critically reviews the latest developments in the palm oil milling process and unit operations leading to process safety concerns. It also discusses the Principle of 3C that is applied to explain repeat accidents and the four-level safety culture in the palm oil milling industry. For this purpose, the author presents case studies of two key palm oil companies in Malaysia. Overall, this paper offers guidelines to leaders in the palm oil milling industry about the required process safety leadership and culture to be understood in order to improve their safety outcomes.
ARTICLE | doi:10.20944/preprints202206.0417.v1
Subject: Materials Science, Nanotechnology Keywords: lecithin; ginger oil; essential oil; nano-lipid; drug delivery system
Online: 30 June 2022 (08:00:31 CEST)
Lipid nanoparticles have an interesting part of drug delivery system. In this study, the modification of the convention nano-lipid based soybean lecithin was demonstrated. Ginger oil derived Zingiber officinale was used along with lecithin, cholesterol and span 80 to fabricate nano-lipid (GL nano-lipid) using thin-film method. Through TEM and confocal microscope, GL nano-lipid exposes the liposome- like morphology. The average size of the resultant nanoparticles was 249.1nm with monodistribution (PDI= 0.021). The ζ-potential of GL nano-lipid was negative as similar to as prepared nano-lipid based lecithin. GL nano-lipid express the highly stable over 60 days of storage at room temperature in term of size, ζ-potential. A shift of pH value from alkaline to acid was detected in lecithin nano-lipid, while with the incorporation of ginger oil, pH value of nano-lipid dispersion was around 7.0. Furthermore, due to the rich of shogaol-6 and other active compounds in ginger oil, the GL nano-lipid is endowed with intrinsic antibacterial feature. In addition, the sulforhodamine B (SRB) assay and live/dead imaging revealed the excellent biocompatibility of GL nano-lipid. Notably, GL nano-lipid was capable to carry the hydrophobic agents as curcumin and perform a pH-dependent release profile. A subsequent characterization are a suitable potential for drug delivery system.
REVIEW | doi:10.20944/preprints202211.0329.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: palm oil industry; palm oil milling; carbon footprint; GHG emissions; sustainability
Online: 17 November 2022 (08:58:55 CET)
Palm oil production involves unit operations that lead to greenhouse gas emissions. A typical mill is estimated to produce greenhouse gas emissions of 637–1,131 kg CO2 eq/t crude palm oil. There has been a huge effort to reduce the carbon footprint of palm oil mills. However, the data from such research have not been consolidated. This paper reviews significant information, results, and conclusions derived from studies in the literature. The latest developments in palm oil milling operations and information on greenhouse gas emissions are presented. Current initiatives in reducing carbon footprint of palm oil mills are discussed along with an assessment of the technologies employed. These include the conventional method of capturing biogas from palm oil mill effluent and emerging approaches such as converting palm sludge oil into biodiesel, deploying enzyme-assisted oil extraction, and converting biomass into fuel for energy generation as an alternative to coal and other fossil fuels. The importance of self-sufficiency is deliberated because a self-sufficient palm oil mill is estimated to reduce emissions by 457 kg CO2 eq/t crude palm oil compared to a mill that requires an external power supply. Methods with the greatest positive effect on the carbon footprint are identified for further investigation.
ARTICLE | doi:10.20944/preprints202209.0405.v1
Subject: Chemistry, Food Chemistry Keywords: deep frying; olive oil; sesame oil; sesame lignans; Total Polar Compounds
Online: 27 September 2022 (03:11:31 CEST)
Fresh potatoes were deep-fried in olive oil (OO) & extra virgin olive oil (EVOO) and their blends with 5%, 10% and 20% v/v sesame oil (SO). This is the first report on the use of sesame oil as natural source of antioxidant for olive oil deep-frying. Oil was evaluated for Peroxide Value (PV), Free Fatty Acids (FFA), K232, K270, Trolox Equivalent Antioxidant Capacity (TEAC) and Total Phenols (TP) until Total Polar Compounds (TPCs) reached 25%. Sesame lignan transformations were monitored through Reverse-phase HPLC. While TPCs in olive oils increased at a steady rate, the addition of 5%, 10% and 20% v/v SO created a time window lasting 1, 2 and 3 hours, respectively, where TPCs were constant. SO addition to OO increased the total frying time. Furthermore, the addition of SO reduced the peroxides formation rate for both OO and EVOO. EVOO was more resistant to oxidation than OO as measured by TPCs and TEAC, while frying time raised from 21.5 to 25.25 h when EVOO replaced OO. The increase in frying time for olive oil but not for extra virgin olive oil, after SO addition, is pointing out a niche market for extra virgin olive oil in deep-frying.
ARTICLE | doi:10.20944/preprints202010.0241.v1
Subject: Materials Science, Biomaterials Keywords: tribotechnical diagnostics; engine oil; wear out; oil change interval; risk analysis
Online: 12 October 2020 (12:44:36 CEST)
This article focuses on the issue of motor oils used in the engines of off-road mobile machinery (NRMM), more specifically tractors. The primary goal of the paper is to determine the appropriate replacement interval for these oils. The physical properties of the examined samples were first determined by conventional instruments. Furthermore, the concentration of abrasive metals, contaminants, and additive elements were measured using an optical emission spectrometer. Lastly, the content of water, fuel, glycol, and the products of oxidation, nitration, and sulphation were determined by using infrared spectrometry. The measured values were compared to the limit values. Based on the processing and evaluation of these analyses, the overall condition of the oils was assessed and subsequently the optimal exchange interval of the examined oils was determined. In addition, a risk analysis of the outage was performed. Due to the high yields of crops, farmers can lose a significant amount of product when a tractor is not functioning during the harvest period. This loss for calculated in the paper.
ARTICLE | doi:10.20944/preprints201810.0493.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: oriental lacquer; oil-modified refined lacquer; drying oil; blending; wood coating
Online: 22 October 2018 (12:17:02 CEST)
Oriental lacquer, a natural and renewable polymeric coating, comes from the sap produced by lacquer trees. For practical application, oriental lacquer must be refined to reduce excess water and enhance its quality. In this study, drying oils were blended with oriental lacquer during the refining process to prepare an oil-modified refined lacquer (OMRL). The type and adding amount (0, 10, and 20% by wt.) of drying oils for wood coatings utilization were evaluated. Rhus succedanea oriental lacquer is composed of 54.1% urushiols, 34.3% water, 7.2% plant gum, and 4.4% nitrogenous compounds, and drying oils, including tung oil (TO), linseed oil (LO), and dehydrated castor oil (DCO) were used as materials in this study. The results show that the drying oil acts as a diluent, which reduces the viscosity and enhances the workability and could shorten the touch-free drying time and speed up the hardened drying of the OMRL. The results also indicate that the hardness, mass retention, Tg, tensile strength, abrasion resistance, and lightfastness of OMRL films decrease as more drying oils are blended. Conversely, the bending resistance, elongation at break, impact resistance increase, and particularly, the gloss, is greatly improved through the blending of more drying oils. In conclusion, the LO-modified refined lacquer (RL) has the highest film gloss and the DCO-modified RL has the shortest drying time for coating; otherwise, the film properties are similar among the three types of drying oil.
ARTICLE | doi:10.20944/preprints202110.0331.v1
Online: 22 October 2021 (13:10:46 CEST)
Oil pollution of extraction areas is an undesirable phenomenon, but very present, es-pecially in old farms. In the context in which the depollution of these areas, in Roma-nia, is carried out from public funds, this fact is more and more difficult to achieve. That is why the effect of pollutants on the environment is being analyzed more and more, it often remains that the depollution is done naturally. This material analyzes the effect of metals present in crude oil (Cu, Pb, Zn, Ag, Ni, Mn, As, Cd, V, Cr, S), on the soil affected by a historical accidental pollution in the Moinesti area, Romania. This article presents the results of analyzes performed by metal detection techniques, namely optical emission spectrophotometry with inductive coupled plasma and atomic absorption spectrophotometry. The metals determined in the polluted soil were statis-tically analyzed regarding the dispersion, standard deviation and coefficient of varia-tion compared to the control sample and compared with the results from two areas in Romania. The risk of exploitation of polluted areas was also analyzed, namely the method of pollution indices and the method of combining the effects of pollutants
ARTICLE | doi:10.20944/preprints202109.0261.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Acetylcholinesterase; Dementia; Essencial oil
Online: 15 September 2021 (13:14:49 CEST)
Alzheimer's disease is characterized by a progressive decline of cognitive functions. The class of drugs used for the treatment are acetylcholinesterase inhibitors. Essential oils have contributed to folk medicine and discovery of new drugs for a long time. The purpose of the study was to investigate the in vitro and in silico the anti-acetylcholinesterase activity, as well as acute toxicity of the essential oil of Lippia origanoides. EOLO was obtained by hydrostelting and analyzed by gas chromatography-mass spectrometry. The inhibition assay of acetylcholinesterase enzyme activity was evaluated in vitro, as well as in silico by docking. The effects of EOLO on hematological, biochemical and behavioral parameters were analyzed in mices. We expose that EOLO shows good anti-acetylcholinesterase activity and low toxicity, possibly resulting from the action of the majority compounds thymol, carvacrol and p-cymene. The anti-acetylcholinesterase potential in vitro demonstrating a 70% inhibition. The docking results elucidated the participation of the major phenolics in AChE inhibition by interacting with the catalytic cavity of AchE. The acute oral toxicity test classified as low toxicity. These results contribute to expand the knowledge about essential oil of Lippia origanoides. Therefore, appears to be promising for herbal medicine production with anti-acetylcholinesterase and antioxidant activity.
ARTICLE | doi:10.20944/preprints201609.0021.v1
Subject: Biology, Entomology Keywords: lemongrass oil; Ligusticum chuanxiong oil; Aphis citricola van der Goot; botanical aphicides
Online: 6 September 2016 (11:52:51 CEST)
In order to develop novel botanical insecticides, the joint action of Ligusticum chuanxiong oil (LCO) and lemongrass oil (LO) against Aphis citricola van der Goot was determined systematically indoors and outdoors. The chemical profiles of LCO and LO as determined by gas chromatography- mass spectrometry analysis revealed that main compounds from LCO were Z-Ligustilide (44.58%) and Senkyunolide A (26.92%), and that of LO were geranial (42.16%) and neral (32.58%), respectively. The mixture of LCO and LO showed significant synergy against A. citricola, with a common-toxicity coefficient (CTC) value of 221.46 at the optimal ratio of LCO to LO (4: 1, w/w). Based on the results of solvents and emulsifiers screening, L. Chuanxiong oil · Lemongrass oil 20% emulsifiable concentrate (20% LCO · LO EC) was developed, which was confirmed to meet the requirements of a commercial pesticide by quality test. Field trials indicated that the insecticidal activity of the diluted 20% LCO · LO EC (1000 fold dilution) was comparable to conventional pesticide (20% imidacloprid EC) on A. citricola 7 days after application. Thus, the mixture of LCO and LO has the potential to be further developed as a botanical pesticide.
TECHNICAL NOTE | doi:10.20944/preprints202009.0357.v1
Subject: Mathematics & Computer Science, Information Technology & Data Management Keywords: data; data paper; omics; metadata; workflow; standards; FAIR principles, MIxS, MINSEQE
Online: 16 September 2020 (11:04:34 CEST)
Data papers have emerged as a powerful instrument for open data publishing, obtaining credit, and establishing priority for datasets generated in scientific experiments. Academic publishing improves data and metadata quality through peer-review and increases the impact of datasets by enhancing their visibility, accessibility, and re-usability. We aimed to establish a new type of article structure and template for omics studies: the omics data paper. To improve data interoperability and further incentivise researchers to publish high-quality data sets, we created a workflow for streamlined import of omics metadata directly into a data paper manuscript. An omics data paper template was designed by defining key article sections which encourage the description of omics datasets and methodologies. The workflow was based on REpresentational State Transfer services and Xpath to extract information from the European Nucleotide Archive, ArrayExpress and BioSamples databases, which follow community-agreed standards. The workflow for automatic import of standard-compliant metadata into an omics data paper manuscript facilitates the authoring process. It demonstrates the importance and potential of creating machine-readable and standard-compliant metadata. The omics data paper structure and workflow to import omics metadata improves the data publishing landscape by providing a novel mechanism for creating high-quality, enhanced metadata records, peer reviewing and publishing of these. It constitutes a powerful addition for distribution, visibility, reproducibility and re-usability of scientific data. We hope that streamlined metadata re-use for scholarly publishing encourages authors to improve the quality of their metadata to achieve a truly FAIR data world.
ARTICLE | doi:10.20944/preprints201909.0335.v1
Subject: Materials Science, Nanotechnology Keywords: polymer hybrid latex; styrene butadiene; emulsion polymerization; printing properties; paper coating
Online: 30 September 2019 (03:17:14 CEST)
Synthesis of styrene butadiene hybrid latex was performed via emulsion polymerization technique using various amount of laponite clay as filler. Laponite clay was modified with cationic surfactant methyl triphenylphosphonium bromide (MTPB) with ion exchange technique prior to polymerization process. The main objective of the modification is to render the surface of the clay layers to more organophilic. Emulsion polymerization was performed under semi batch process using 2 L laboratory stainless steel reactor with temperature 85°C to 90°C for 8 hours. Polymer hybrid styrene butadiene latex was characterized for its physical and chemical properties with standard ASTM Methods. Characterization of its binding and printing properties were carried out with standard testing method (TAPPI Methods) using single coating formulation on 80 gsm woodfree paper. Polymer hybrid latex based on styrene and butadiene monomers with laponite clay enhanced binding and printing properties of coated paper, addition of laponite clay to 6.0 wt % increased the binding resistance of the coated paper two times higher than pure latex. Reducing binder level become possible for cost saving.
ARTICLE | doi:10.20944/preprints201706.0062.v1
Subject: Social Sciences, Library & Information Science Keywords: h-index; citations; published version; Scopus database; highly cited paper; bibliometrics
Online: 14 June 2017 (06:07:12 CEST)
The number of citations that a paper has received is the most commonly used indicator to measure the quality of research. Researchers, journals, and universities want to receive more citations for their scholarly publications to increase their h-index, impact factor, and ranking respectively. In this paper, we tried to analyses the effect of the number of available Google Scholar versions of a paper on citations count. We analyzed 10,162 papers which are published in Scopus database in year 2010 by Malaysian top five universities. Then we developed a software to collect the number of citations and versions of each paper from Google Scholar automatically. The result of spearman correlation coefficient revealed that there is positive significant association between the number of Google Scholar versions of a paper and the number of times a paper has been cited.
ARTICLE | doi:10.20944/preprints202212.0489.v1
Subject: Social Sciences, Law Keywords: Petroleum Resources; Contract Structure; Production Sharing Agreement; International Oil Company; National Oil Company
Online: 26 December 2022 (12:03:54 CET)
Most developing countries with petroleum resources are constrained in the ability to refine their oil and gas resources. This virtually results in the involvement of the International Oil Company (IOC) by the National Oil Company (NOC) of a particular nation to enter into an agreement to achieve the production of oil based on an agreed framework. However, in cur-rent development, there is little focus on the contractual agreement, particularly on the pro-duction sharing agreement by the IOC in the exploration of petroleum resources of developing countries. The primary objective of this paper is to critically explore the contract structure of production sharing agreement by the IOC in the exploration and development of petroleum resources in developing countries. Content analysis was used as the methodology of the study after examining several literatures. The findings indicate that the contract structure of the production sharing agreement (PSA) between NOC and IOC plays a significant role in the cost and risk of exploration and development of oil. In addition, it is noted that the joint committee of the NOC and IOC plays a paramount role in monitoring the operations of PSA between the NOC and IOC. Hence, from the gross oil production, the NOC gets its share as profit while IOC gets its share income tax. As an instrument of contract structure in the oil and gas sector, PSA needs further entrenchment between IOC and NOC to avoid likely issues that can emanate between the two parties in the face of current developments.
ARTICLE | doi:10.20944/preprints202106.0456.v1
Online: 17 June 2021 (10:17:15 CEST)
Abstract: The effect of some weather parameters (rainfall and temperature) on the production of oil palm in Peninsular Malaysia was investigated. Data were analysed using the Statistical Package for Social Sciences (SPSS 20.0 version), with descriptive statistics, time series analysis, and multiple linear regression (MLR) carried out. SPSS and Microsoft Excel 2010 were used to analyse the results. The MLR model determined the strength of the relationship between oil palm yield (dependent variable) and the changing variables of temperature and rainfall (independent variables). The regression output returned three components; regression coefficients, regression statistics and ANOVA. The findings of the study revealed medium to high rainfall variability at the rate of 0.0008. This implies that rainfall is increasing over time with variations in its amount and intensity. As rainfall increases oil palm FFB production is predicted to increase at a slow rate of 0.0009. The estimation of average annual temperature indicated an increase of 5.6℃ at the rate of 0.0357℃ per year with a temperature maximum of 32.01℃ and minimum of 25.45℃. The result also revealed an increase in oil palm yield at the rate of 0.2581 per year with a mean value of 176247.6. Overall, there is a significant difference in the impact of rainfall and temperature on oil palm yield. This signifies that rainfall has a significant impact on oil palm yield (FFB) compared to temperature.
ARTICLE | doi:10.20944/preprints202010.0542.v1
Online: 27 October 2020 (09:04:36 CET)
This study determines the management of downstream oil palm development in the technopolitan areas of Pelalawan Regency. The study object was analyzed qualitatively in stages, including the development, potential, and management of downstream oil palm. The results show that the downstream oil palm facilitates the development of various ideas, innovations, and knowledge from the use of products with high selling value. This supports the government, academia, business, and society in implementing Good Agricultural Practice (GAP). The downstream oil palm development in Pelalawan Regency is managed in an integrated, competitive, and sustainable manner. This allows all stakeholders and society (independent smallholders) to receive economic, social, and environmental benefits.
ARTICLE | doi:10.20944/preprints201805.0442.v2
Online: 27 July 2018 (06:19:37 CEST)
Oil spills are adverse events that may be very harmful to ecosystems and food chain. In particular, large sea oil spills are very dramatic occurrence often affecting sea and coastal areas. Therefore the sustainability of oil rig infrastructures and oil transportation via oil tankers are linked to law enforcement based on proper monitoring techniques which are also fundamental to mitigate the impact of such pollution. Within this context, in this study a meaningful showcase is analyzed using remotely sensed measurements collected by the Synthetic Aperture Radar (SAR) operated by the COSMO-SkyMed (CSK) constellation. The showcase presented refers to the Deepwater Horizon (DWH) oil incident that occurred in the Gulf of Mexico in 2010. It is one of the world's largest incidental oil pollution event that affected a sea area larger than 10,000 km2. In this study we exploit, for the first time, dual co-polarization SAR data collected by the Italian CSK X-band SAR constellation showing the key benefits of HH-VV SAR measurements in observing such a huge oil pollution event, especially in terms of the very dense revisit time offered by the CSK constellation.
ARTICLE | doi:10.20944/preprints201705.0011.v1
Online: 1 May 2017 (10:09:39 CEST)
The biophenol integral extraction protocol from vegetation water developed in the early 2000s for the three-phase olive mill was adapted to a large two-phase mill operating in Sicily during the 2016/2017 season. The new set-up allows extensive recovery of olive phenolics, transforming previous waste into a source of revenues for the milling company and of valued bioproducts for its bioeconomy partner, while eliminating a source of potential pollution altogether.
ARTICLE | doi:10.20944/preprints202110.0323.v1
Subject: Chemistry, Chemical Engineering Keywords: Hydrogel; Blended paper; Slow-release fertilizer; Hydroxy Propyl Methyl Cellulose; polyvinyl alcohol
Online: 22 October 2021 (09:48:48 CEST)
In this study, a slow-release urea fertilizer hydrogel was synthesized from hydroxyl propyl methyl cellulose, polyvinyl alcohol and glycerol blends with paper (blended paper) as second layer. The fertilizer hydrogel was characterized by SEM, XRD and FTIR. Its retention in sandy soil, swelling behavior in distilled and tap water as well as slow-release behavior to urea were investigated. The results indicated that the fertilizer had good slow-release properties and ability to retain water in soil. However, the addition of blended paper as a second layer matrix was found to help improve the release properties of the fertilizer. The swelling kinetic of the hydrogel followed the Schott’s Second order model. The release kinetics of urea in water was best described by the Zero order model signifying that the release behavior was independent of fertilizer concentration
REVIEW | doi:10.20944/preprints202104.0794.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Ketogenic Diets; Ketosis; Ketones; Consensus Statement; Position Paper; Headache; Migraine; Cluster Headache
Online: 30 April 2021 (15:38:37 CEST)
Headaches are among the most prevalent and disabling disorders and there are several patients’ unmet needs in current pharmacological options, while a growing interest is focusing on nutritional approaches as non-pharmacological treatments. Among these, the most promising seems to be the ketogenic diet (KD). Exactly 100 years ago, KD was used to treat pediatric forms of drug-resistant epilepsy, but progressively applications of this diet also involved adults and other neurological disorders. Evidence of KD effectiveness in migraine comes from 1928, but in the last years different groups of research and clinicians paid attention to this therapeutic option to treat patients with drug resistant migraine and cluster headache, and/or comorbid with metabolic syndrome. Here we describe all the existing evidence on the potential benefits of KDs in headaches, explore in deep all the potential mechanisms of action involved in the efficacy, and synthesize results of working meetings of an Italian panel of experts on this topic. Aim of the working group is the creation of a consensus on indications and clinical practice to treat with KDs patients with headache. The results here we present are the base for further improvement in the knowledge and application of KDs in the treatment of headaches.
ARTICLE | doi:10.20944/preprints201808.0402.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: classification; computational intelligence methods; discrimination power; LIBS; machine learning; paper-ink analysis
Online: 23 August 2018 (04:54:18 CEST)
Laser-induced breakdown spectroscopy (LIBS) is an important analysis technique with applications in many industrial branches and fields of scientific research. Nowadays, the advantages of LIBS are impaired by the main drawback in the analysis of collected data. This procedure is essentially based on the comparison of lines present in the spectrum with a literature database. This paper proposes the use of various computational intelligence methods to develop a reliable and fast classification of non-destructively acquired LIBS spectra into a set of predefined classes. We focus on a specific problem of classification of paper-ink samples into 30 separate, predefined classes. For each of 30 classes (10 pens of each of 5 ink types combined with 10 sheets of 5 paper types plus empty pages) 100 LIBS spectra are collected. Four variants of preprocessing, seven classifiers (Decision trees, Random forest, k-Nearest Neighbour, Support Vector Machine, Probabilistic Neural Network, Multi-Layer Perceptron, and Generalized Regression Neural Network), 5-fold stratified cross-validation and test on an independent set (for methods evaluation) scenarios are employed. Our developed system yielded an accuracy of 99.08% with average classification time of about 0.12 s is obtained using the random forest classifier. Our results clearly demonstrates that machine learning methods can be used to identify the paper-ink samples based on LIBS reliably at a faster rate.
Subject: Chemistry, Chemical Engineering Keywords: ASP flooding; low permeability oil layer; partial quality tool; maximum injection pressure; oil recovery
Online: 13 November 2019 (03:38:54 CET)
In order to solve the problem of the poor oil displacement effect of high molecular weight alkali/surfactant/polymer (ASP) solution in low permeability reservoirs, Daqing Oilfield uses a partial quality tool to improve the oil displacement effect in low permeability reservoirs. Without changing the oil displacement capability of high molecular weight ASP solution in high permeability oil layers, the ASP solution is actively sheared in low permeability oil layers by using a partial quality tool to increase the injection capability of the solution and improve the overall oil recovery. In order to study the ability of the partial quality tool to improve the oil displacement effect, firstly, the matching degree of high molecular weight ASP solution to low permeability cores is studied, and the ability of quality control tools to change the molecular weight is studied. Then, experimental research on the pressure and oil displacement effect of high molecular weight ASP solution before and after the actions of the partial quality tool is carried out. The results show that ASP solutions with molecular weights of 1900 × 104 and 2500 × 104 have a poor oil displacement effect in low permeability reservoirs. After the action of the partial quality tool, the injection pressure is reduced by 5.22 MPa, and the oil recovery is increased by 7.79%. The injection pressure of the ASP solution after shearing by the partial quality tool is lower than that of the ASP solution with the same molecular weight and concentration without shearing, but the oil recovery is lower. On the whole, the use of the partial quality tool can obviously improve the oil displacement effect in low permeability reservoirs.
TECHNICAL NOTE | doi:10.20944/preprints202111.0349.v1
Subject: Earth Sciences, Oceanography Keywords: oil-in-water emulsion; seawater; oil pollution detection; radiance reflectance; Monte Carlo simulation, spectral index
Online: 19 November 2021 (12:28:40 CET)
The presented results of simulations take into account the optical parameters of the selected sea region (from literature data on the southern Baltic Sea) and two optically extreme types of crude oil (from historical data) which exist in the form of a highly diluted oil-in-water emulsion (10 ppm). The spectral index was analyzed based on the results of modelling the radiance reflectance distribution for almost an entire hemisphere of the sky (zenith angle from 0 to 80o). The spectral index was selected and is universal for all optically different types of oil (wavelengths 650 and 412 nm). The possibility of detecting pollution in the conditions of the wavy sea surface (as a result of wind of up to 10 m/s) was studied. It has been also shown that if the viewing direction is close to a direction perpendicular to the sea surface, observations aimed at determining the spectral index are less effective than observation under the zenith angle of incidence of sunlight for all azimuths excluding the direction of sunlight specular reflection.
ARTICLE | doi:10.20944/preprints201609.0081.v1
Subject: Earth Sciences, Environmental Sciences Keywords: spectral reflectance; vegetation indices; vegetation; remote sensing; oil spill; mangrove forest; oil pollution; Landsat 8
Online: 23 September 2016 (06:19:49 CEST)
This study is aimed at demonstrating application of vegetation spectral techniques for detection and monitoring of impact of oil spills on vegetation. Vegetation spectral reflectance from Landsat 8 data were used in the calculation of five vegetation indices (normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), adjusted resistant vegetation index 2 (ARVI2), green-infrared index (G/NIR) and green-shortwave infrared (G/SWIR) from the spill sites (SS) and non-spill (NSS) sites in 2013 (pre-oil spill), 2014 (oil spill date) and 2015 (post-oil spill) for statistical comparison. The result shows that NDVI, SAVI, ARVI2, G/NIR and G/SWIR indicated certain level difference between vegetation condition at the SS and the NSS were significant with p-value <0.5 in December 2013. In December 2014 vegetation conditions indicated higher level of significant difference between the vegetation at the SS and NSS as follows where NDVI, SAVI and ARVI2 with p-value 0.005, G/NIR - p-value 0.01 and GSWIR p-value 0.05. Similarly, in January 2015 a very significant difference with p-value <0.005. Three indices NDVI, ARVI2 and G/NIR indicated highly significant difference in vegetation conditions with p-value <0.005 between December 2013 and December 2014 at the same sites. Post—spill analysis show that NDVI and ARVI2 indicated low level of significance difference p-value <0.05 suggesting subtle change in vegetation conditions between December 2014 and January 2015. This technique is essential for real time detection, response and monitoring of oil spills from pipelines for mitigation of pollution at the affected sites in the mangrove forest.
ARTICLE | doi:10.20944/preprints202212.0435.v1
Subject: Materials Science, Nanotechnology Keywords: biopolymers; nanoparticles; garlic essential oil; packaging
Online: 23 December 2022 (02:01:47 CET)
Edible films were produced combining pectin (P) matrix with chitosan nanoparticle (CSNP), polysorbate 80 (T80), and garlic essential oil (GEO) as an antimicrobial agent. The CSNP were analyzed for their size and stability, and the films, throughout their contact angle, scanning electron microscopy (SEM), mechanical and thermal properties, WVP and antimicrobial activity. Four filming-forming suspension were investigated: PGEO (control); PGEO@T80; PGEO@CSNP; PGEO@T80@CSNP. The average particle size was 317nm with zeta potential reaching +21.4 mV, which indicated colloidal stability. The wettability of the films exhibited values of 65°, 43°, 78°, 64° respectively. In antimicrobial tests, the films containing GEO showed inhibition only by contact for S.aureus. For E. coli, the inhibition occurred only in films containing CSNP and by direct contact in the culture. The results indicate a promising alternative for designing stable antimicrobial nanoparticles for application in novel food active packaging.
ARTICLE | doi:10.20944/preprints202109.0186.v1
Online: 10 September 2021 (11:26:59 CEST)
sustainability reporting, critical paradigm, upstream oil, and gasThe operating activities of the upstream oil and gas industry directly impact the environment. This industry faces significant social challenges and directly impacts the environment. Many Reputable international sustainability institutions organize sustainability awards. However, community conditions do not have a positive impact on sustainability practices. There are vari-ous serious violations related to sustainability, environmental pollution, multiple cases of cor-ruption, human rights, and other violations. In contrast, the companies receiving this award also received inspection findings of violations committed by The Audit Board of the Republic of In-donesia. This study uses critical discourse analysis that begins with phenomena related to viola-tions of sustainability reporting from scientific journals and other references using a systematic literature review approach over the last ten years. It produces a critical paradigm that is not val-ue-free, which is the basis for framing thought utilizing the theory of hegemony. The results of this study indicate that the upstream oil and gas industries are obliged to implement Corporate Social Responsibility (CSR) practices and Sustainability Reports (SR), has biased factors that are contrary to the sustainability concept and are not under the sustainability award based on evi-dence obtained from the stages of manuscript analysis with systematic literature review
TECHNICAL NOTE | doi:10.20944/preprints202012.0300.v1
Subject: Mathematics & Computer Science, General & Theoretical Computer Science Keywords: Post Quantum Cryptography, Oil and Vinegar
Online: 13 December 2020 (21:31:13 CET)
Public key encryption methods are often used to create a digital signature, and where Bob has a public key and a private key. In order to prove his identity, he will encrypt something related to the message with his private key, and which can then be checked with his public key. The main current methods of public-key encryption include RSA and ECC (Elliptic Curve Cryptography), and which involve computationally difficult operations. But these operations have not been proven to be hard in an era of quantum computers. One well-known hard problem is the solving of quadratic equations with $m$ equations with $n$ variables. This is a known NP-hard problem, even in a world of quantum computers. These can be used as post-quantum signature schemes and which involve multivariate equations. In order to understand these methods, this paper outlines a simple example of implementing the oil and vinegar method, and where we have a number of unknown oil variables and a number of known vinegar variables, and where the vinegar variables help convert the hard problem into an easy one.
ARTICLE | doi:10.20944/preprints202012.0197.v1
Subject: Life Sciences, Biochemistry Keywords: Bioadsorbents; biodiesel; waste cooking oil; purification
Online: 8 December 2020 (10:03:26 CET)
The dry washing method is an alternative to replace water washing, thereby reducing the negative impacts of contamination. However, commercial adsorbents come from industrial processes that, due to their composition, may not be such a sustainable resource in the global biodiesel production process. In this study, the use of organic residues, such as sawdust, coconut fiber, nutshell, rice husk and water hyacinth fiber, were proposed as bioadsorbents for the purification of biodiesel from waste cooking oil (WCO). Quality parameters such as the acid value, water content, and free and total glycerin content were evaluated and compared with those of commercial resins such as Magnesol® and Amberlite™. Promising results were obtained using sawdust during the purification process, achieving a 31.6% reduction in the acid value compared to that of unpurified biodiesel, the reduction was 31.3% more efficient than Amberlite™. Sawdust adsorbed free glycerin at 55.8%, being more efficient than Amberlite™. The total glycerin values were similar between commercial resins and sawdust. A water content values were similar than Amberlite™ and better than that with Magnesol®, at 4.3% and 39.81%, respectively. These results show that sawdust can be used as an alternative bioadsorbent in a dry purification method for biodiesel being a residue with less environmental impact.
REVIEW | doi:10.20944/preprints202009.0497.v1
Online: 21 September 2020 (07:20:59 CEST)
To evaluate the efficacy of fish oil for protection against coronary heart disease (CHD), we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating the use of fish oil for protection against CHD. We retrieved relevant articles published from January 1966 to January 2020 by searching the PubMed, EMBASE, Cochrane CENTRAL, and Web of Science databases. RCTs of fish oil in preventing CHD were selected. The study quality was evaluated using the Cochrane Risk of Bias tool with RevMan 5.3 software. The first selection involved 350 citations. After screening and evaluation of suitability, 19 RCTs adjusted for clustering were included in the meta-analysis. All selected manuscripts considered that fish oil was effective in preventing CHD, secondary outcome measures included angina, sepsis and death. Compared with the control group, fish oil may confer significant protection against CHD (odds ratio = 0.84; 95% confidence interval: 0.72–0.98). There was no significant difference in the incidence of secondary outcomes between the observation group and the control group (P > 0.05). The above results show that fish oil plays an important role in reducing CHD and cardiovascular events. However, because of the suboptimal quality of the studies included into the meta-analysis, these results do not justify adding fish oils systematically to the heavy pharmaceutical assortment already recommended in CHD patients.
REVIEW | doi:10.20944/preprints202001.0079.v1
Online: 9 January 2020 (09:44:35 CET)
Implementation of waterflood is with injected pressured water to reservoir to escalation oil production. Produced water is the dominated result from oil and gas mechanism in this world meanwhile 65% of water is injected back to the well for pressure maintenance, 30% for discharge aquifier condition and surface. For shaly sand, produced water usually bring coarse and suspended sand to the surface. Therefore, this sand level is needed to declining to avoid plugging in injection well until certain economic condition.
ARTICLE | doi:10.20944/preprints201804.0385.v1
Subject: Materials Science, Polymers & Plastics Keywords: Oil palm; Liquefaction; Residue; Polyhydric alcohols
Online: 30 April 2018 (18:50:24 CEST)
Resides derived from liquefaction of oil palm trunk in the presence of polyhydric alcohol with different liquefaction temperature and time were characterized to provide a new approach to understand some fundamental aspects of the liquefaction reaction. Higher temperature and longer reaction time resulted in lower residue content, indicating more decomposition of components of oil palm trunk. The amorphous polymer comprised of lignin, hemicellulose, starch, and cellulose with non-crystalline structure are firstly degraded at low liquefaction temperature, followed by the decomposition of crystalline region of cellulose. Although it was relatively difficult to destroy the ordered structure of cellulose, most of them could be liquefied via prolonging reaction time or enhancing reaction temperature. Nevertheless, it was found that re-condensation of liquefied products occurred during the liquefaction process when higher temperature of 180 oC was used after 60 min, leading to the gradual increase of residue content with increase of reaction time.
ARTICLE | doi:10.20944/preprints201608.0201.v1
Subject: Engineering, Marine Engineering Keywords: oil; seawater; suspension; detection; radiance reflectance
Online: 24 August 2016 (10:18:14 CEST)
Oil floating on the sea surface can be detected by both passive and active methods using the ultraviolet-to-microwave spectrum, whereas oil immersed below the sea surface can signal its presence only in visible light. This paper presents an optical model of a sea area deeply polluted by an oil suspension (10 ppm) located in a layer (thickness 5 m) separated from the sea surface by a clear layer (thickness 1 m). The impact of wavelength and state of the sea surface on reflectance changes is shown based on the results of Monte Carlo ray tracing. A two-wavelength index of reflectance is proposed to detect oil suspended in the water column (645-469 nm).
ARTICLE | doi:10.20944/preprints201910.0372.v1
Subject: Chemistry, Organic Chemistry Keywords: antimicrobial additive agent; cationic-xylan; Escherichia coli; mechanical properties; paper products; PHGH; thermal stability
Online: 31 October 2019 (10:22:43 CET)
In this work, a xylan-based antimicrobial additive agent was prepared and aimed for uses in paper products against Escherichia coli bacteria. The derived Cationic-Xylan-grafted-PHGH (CX-g-PHGH) was successfully synthesized by graft copolymerization of cationic-xylan with guanidine polymer (PHGH) using ceric ammonium nitrate as initiator. The obtained CX-g-PHGH had maximum PHGH grafting ratio of 18.45% and efficiency of 58.45%, and showed good viscosity and thermal stability. Furthermore, the paper samples prepared in this work were reinforced obviously with the addition of CX-g-PHGH by improved mechanical properties. Compared to the reference paper without any of the xylan-derivatives, the index of tensile, tear, burst and folding endurance of the paper had increases up to 20.07%, 25.31%, 30.20% and 77.78%, respectively. Moreover, the prepared CX-g-PHGH paper exhibited an efficient antimicrobial activity against E. coli bacterial, by which a lot of applications based on the new xylan-derived additive agent obtained in this work could be found, especially in field of antimicrobial paper products against E. Coli bacteria from contaminated food.
ARTICLE | doi:10.20944/preprints201910.0287.v1
Subject: Chemistry, Chemical Engineering Keywords: membrane bio-reactor (mbr); ozone oxidation; paper and papermill; fluorescent whitening agents; water reuse
Online: 25 October 2019 (11:34:11 CEST)
In this study, effluent water was produced through Submerged Membrane Bio-Reactor (SMBR) process, which is a simple system and decomposes organic matter contained in wastewater with biological treatment process and performs solid-liquid separation, Especially, ozone oxidation treatment process is applied to effluent water containing fluorescent whitening agent, which is a trace pollutant which is not removed by biological treatment, and influences the quality of reused water. The concentration of COD in the SMBR was 449.3 mg/ℓ-COD, and the concentration of permeate water was 100.3 mg/ℓ-COD. The removal efficiency was about 70.1%. The amount of ozone re- quired for the removal of the fluorescent whitening agent in the permeated water in SMBR was 6.67 g-O3/min, and the amount of ozone required to remove COD relative to the permeate water was calculated to remove 0.997 mg-COD for 1 mg of O3.
ARTICLE | doi:10.20944/preprints202212.0317.v1
Online: 19 December 2022 (03:54:13 CET)
We investigate the determinants of U.S. bilateral imports of olive oil and their dynamics from shocks in foreign supplies and changes in U.S. olive oil demand, using an augmented gravity framework that leads to an equilibrium of bilateral trade flows from olive oil exporters to the U.S. market. The empirical specification is applied at the disaggregated HS-6 level in a panel dataset, and three estimation techniques (truncated OLS, PPML, Heckman), for which the latter two account for zero trade flows, the extensive margin of trade and the potential censored distribution of exports with zero trade flows. We run Reset and HPC tests to qualify our results. On the supply side, exporters’ capacity to exports, multilateral trade resistance, and immigrants’ networks into the US are strong determinants of the bilateral trade flows for both aggregate olive oil exports and for virgin olive oil exports, On the consumer side, U.S. GDP, the import unit value, and immigrant network effects are robust determinants of bilateral flows as well for aggregate and virgin olive oil trade flows. Migrants’ stock, exporters’ GDP and population, and total exports revenues increase the probability of an exporter entering the U.S. market. We could not find robust evidence of consumer behavior being influenced by popular press measures of the emergence of Mediterranean diet and olive oil, or measures of cultural globalization of U.S. consumers.
ARTICLE | doi:10.20944/preprints202101.0072.v1
Online: 5 January 2021 (10:28:29 CET)
Many countries are raising questions on the intentions behind Saudi reforms. The low oil prices in 2008-09 were the awakening call for Saudis, and later in 2014, it became the reason to look for the economy that is less dependent on oil. The article studies the initiated social reforms and social impact of foreign cultural activities. It scrutinizes the Saudi social fabric under the social exchange theory and looks for the positive and negative effects of cultural exchanges. The paper also considers the COVID-19 situation in KSA as it has broken the chain of cultural events planned all over the country to promote tourism and improve the image of KSA.
ARTICLE | doi:10.20944/preprints202011.0496.v1
Subject: Social Sciences, Accounting Keywords: resource management; oil curse; footprint; fiscal policy
Online: 19 November 2020 (08:41:25 CET)
The resource curse indicates that economic growth performs poorly in countries with significant natural resources. Nevertheless, certain countries rich in energy managed to protect their resource riches in the long run. It is necessary to enforce effective policies in resource-rich countries to fully leverage the advantages which can come from the abundance of natural resources. This study aimed to evaluate how oil-rich countries would avoid resource flows by successful fiscal and management policies. By taking the guidance of Norway and implementing fiscal policy focused on tax rules on its oil management, it is proposed that oil-exporting countries benefit significantly. The framework attempts to mitigate this resource curse and utilise oil revenues in the interest of the country.
ARTICLE | doi:10.20944/preprints202003.0455.v1
Online: 31 March 2020 (10:16:13 CEST)
Background: COVID-19, a member of corona virus family is spreading its tentacles across the world due to lack of drugs at present. Associated with its infection are cough, fever and respiratory problems causes more than 15% mortality worldwide. It is caused by a positive, single stranded RNA virus from the enveloped coronaviruse family. However, the main viral proteinase (Mpro/3CLpro) has recently been regarded as a suitable target for drug design against SARS infection due to its vital role in polyproteins processing necessary for coronavirus reproduction.Objectives: The present in silico study was designed to evaluate the effect of Eucalyptol (1,8 cineole), a essential oil component from eucalyptus oil, on Mpro by docking study.Methods: In the present study, molecular docking studies were conducted by using 1-click dock and swiss dock tools. Protein interaction mode was calculated by Protein Interactions Calculator.Results: The calculated parameters such as RMSD, binding energy, and binding site similarity indicated effective binding of eucalyptol to COVID-19 proteinase. Active site prediction further validated the role of active site residues in ligand binding. PIC results indicated that, Mpro/eucalyptol complexes forms hydrophobic interactions, hydrogen bond interactions and strong ionic interactions.Conclusions: Therefore, eucalyptol may represent potential treatment potential to act as COVID-19 Mpro inhibitor. However, further research is necessary to investigate their potential medicinal use.
ARTICLE | doi:10.20944/preprints202001.0198.v1
Subject: Engineering, Other Keywords: transplanter; hydraulic oil; temperature; viscosity; proportional valve
Online: 18 January 2020 (09:24:36 CET)
This study was conducted to develop a PID control algorithm considering viscosity for the planting depth control system of a rice transplanter using various hydraulic oils at different temperatures and to evaluate the performance of the control algorithm, and compare the performance of the PID control algorithm without considering viscosity and considering viscosity. In this study, the simulation model of the planting depth control system and a PID control algorithm were developed based on the power flow of the rice transplanter (ERP60DS). The primary PID coefficients were determined using the Ziegler–Nichols (Z–N) second method. Routh’s stability criteria were applied to optimize the coefficients. The pole and double zero points of the PID controller were also applied to minimize the sustained oscillations of the responses. The performance of the PID control algorithm was evaluated for three ISO (The International Organization for Standardization) standard viscosity grade (VG) hydraulic oils (VG 32, 46, and 68). The results show that the control algorithm considering viscosity is able to control the pressure of the proportional valve, which is associated with the actuator displacement for various types of hydraulic oils. It was noticed that the maximum pressure was 15.405 bars at 0, 20, 40, 60, 80, and 100 ℃ for all of the hydraulic oils. The settling time and steady-state errors were 0.45 s at 100 ℃ for VG 32, and 0% for all of the conditions. The maximum overshoots were found to be 17.50% at 100 ℃ for VG 32. On the other hand, the PID control algorithm without considering viscosity could not control the planting depth, because the response was slow and did not satisfy the boundary conditions. The PID control algorithm considering viscosity could sufficiently compensate for the nonlinearity of the hydraulic system and was able to perform for any of temperature-dependent viscosity of the hydraulic oils. In addition, the rice transplanter requires a faster response for accurately controlling and maintaining the planting depth. Planting depth is highly associated with actuator displacement. Finally, this control algorithm considering viscosity could be helpful in minimizing the tilting of the seedlings planted using the rice transplanter. Ultimately, it would improve the transplanter performance.
REVIEW | doi:10.20944/preprints202001.0115.v1
Subject: Engineering, Energy & Fuel Technology Keywords: electrical heating; heavy oil; visocsity; energy efficiency
Online: 12 January 2020 (13:25:53 CET)
This paper presents a review of the electrical heating method for heavy oil recovery based on past, current, and future prospects of electrical heating. Heavy oil is one of the potential crude oil used as a link to reduce the crisis of light oil used today. The obstacle of heavy oil is a high viscosity and density in which thermal injection is a method for heavy oil recovery, but it results in economic and environmental issues. Electrical heating is one of the thermal methods by transferring heat into the reservoir. The basic process of electrical heating is to increase the mobility of the oil. Because the temperature rises, it can reduce oil viscosity and makes it easier for heavy oil to flow. The past and current developments have been carried out to fill up the gap of electrical heating projects. The future prospects must meet energy efficiency, and the excessive heat will damage formation that must be tackled in the future prospect. the works adopt several electrical heating projects and applications in the world where the works give a brief future prospect of electrical heating.
ARTICLE | doi:10.20944/preprints201908.0268.v1
Subject: Keywords: Soybeans, Soxhlet extraction, Oil extract, solvent, Yield
Online: 26 August 2019 (13:54:14 CEST)
This work is aimed at promoting a healthier means of livelihood by investigating insignificant areas of pollution. In this work, soy candles produced from soybeans were proven as healthier alternatives to paraffin candles. Soxhlet extraction method was used with hexane as solvent. The extracted oil were then solidified. The wax was moulded into candle and tests were carried out to prove its claims as a safer alternative to paraffin wax. The results supported this claims that soy candles is more economical and produced lesser soot than the paraffin candles.
ARTICLE | doi:10.20944/preprints201908.0114.v1
Online: 9 August 2019 (03:40:43 CEST)
Purpose: The purpose of this paper is to explore and analyse the dynamic relationship between remittances inflows of Egyptians working abroad and asymmetric oil price shocks. Design: This study uses a vector autoregressive (VAR) model to explain the impulse response functions (IRFs) and the forecast error variance decomposition (FEVD). The rationale behind using these tools is its ability to examine the dynamic effects of our variables of interest. Findings: The impulse response functions confirmed that remittance inflows have various responses to asymmetric oil price shocks. For instance, inflowing remittances increase in response to positive oil price shocks, while it decreases in response to negative oil price shocks. Also, the results indicate that the responses are significant in the short and medium-run and insignificant in the long run. The magnitude of these responses reaches its peak or trough in the third year. Further, the variance decomposition reveals that oil price decreases are more influential than oil price increases. Originality: This means that remittances inflows in Egypt are pro-cyclical with oil price shocks. That explained by the fact that more than one-half of those remittances sent from GCC countries where real economic growth is very pro-cyclical with the oil prices. This empirical assessment will help policymakers to determine the behaviour of remittances and highlights the impact of different kinds of oil prices shocks on remittances. Unlike the little existing literature, this study is the first study applied the VAR model using a novel dataset spanning 1960-2016.
ARTICLE | doi:10.20944/preprints201902.0218.v1
Online: 25 February 2019 (08:50:48 CET)
Abstract: In this study the essential oils of Salvia officinalis growing in Sudan, were obtained by hydrodistillation and analyzed by Gas chromatography mass spectrometer, forty tow compounds were identified. The essential oil composition of S.officinalis found that it had many important compounds. The detected main compounds were oxygenated monoterpenes followed monohydrocarbone, squiterpenes and other compounds. The main essential oil constituents were α-terpineol (33.07%), camphor (11.57%), α-pinene (8.96%) camphene (5.09%) β-cymen (5.40 %) caryphyllene (3.76%) β-myrcene (3.65%) β-menth1-en-b-ol (3.45%) bomeol (3.38%) β-pinene (2.74%) Epiglobulol (2.59%) 1,8 Cineol (2.24%) and trans-β- terpinyl butanone(2.00% ).
ARTICLE | doi:10.20944/preprints201808.0404.v1
Subject: Materials Science, Polymers & Plastics Keywords: adhesive; bamboo charcoal; castor oil; composites; polyurethane
Online: 23 August 2018 (05:15:45 CEST)
Polyurethane (PU) foam adhesives were prepared from castor oil as a polyol with isocyanate poly (4,4′-methylene diphenyl isocyanate) (PMDI) using a solvent-free process. The NCO/OH molar ratio used for the preparation of PU foams was 1.5. Water, organosiloxane and dibutyltin dilaurate were blowing agent, surfactant and catalyst, respectively. Effects of the ratio of blowing agent and catalyst were adjusted to optimize the properties. The results show that 4 wt% of castor oil of catalyst and blowing agent minimizes water absorption and maximizes volume expansion in the PU foams. FT-IR analysis shows that urethane bond was formed by hydroxyl group of castor oil and –NCO group of isocyanate PMDI. More blowing agent and catalyst could improve the volume expansion ratio and reduce water retention of PU foams. It was found that Moso bamboo charcoal (Phyllostachys pubescens) or/and China fir wood particle (Cunninghamia lanceolate) composites with setting densities of 500 and 600 kg/m3 can be prepared from optimized castor oil-based PU foam adhesive at 100 °C for 5 min under a pressure of 1.5 MPa. Increasing the amount of bamboo charcoal decreases the equilibrium moisture content, water absorption and internal bonding strength of the composite. Notably, bamboo charcoal composite exhibits excellent dimensional stability. The optimized density and bamboo charcoal percentages of the composite were 500 kg/m3 and 50 to 100%. The castor oil-based PU composites containing bamboo charcoal fulfilled the CNS 2215 standards for particleboard. This dimensionally stable, low-density bamboo charcoal composite has high potential to replace current indoor building materials.
ARTICLE | doi:10.20944/preprints201806.0386.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: essential oil; Psoralea corylifolia; cytotoxicity; encapsulation; solubilisation
Online: 25 June 2018 (12:00:52 CEST)
Babchi (Psoralea corylifolia) oil is an important essential oil used in several traditional medicines to cure various disorders. This phytotherapeutic agent possesses number of pharmacological activities including antibacterial, antifungal, antioxidant, anti-inflammatory, immunomodulatory and antitumor. However, volatile nature, poor stability and solubility of babchi oil (BO) restrict its pharmaceutical applications. Hence, the aim of the present work was to encapsulate this oil in β-cyclodextrin nanosponges (NS) in order to overcome above limitations. To fabricate nanosponges, β-cyclodextrin was crosslinked with diphenyl carbonate in different molar ratios viz.1:2, 1:4, 1:6, 1:8 and 1:10. The blank nanosponges were loaded with babchi oil using freeze-drying method. Particle size of the babchi oil loaded nanosponges was found to lie between 200-500 nm, with low polydispersity index. Further, zeta potential, Fourier transform infrared spectroscopy, X-ray diffraction, thermal analysis and electron microscopy were carried out for characterization of babchi oil nanosponges. Results obtained from spectral analysis ascertained the formation of inclusion complexes. Additionally, solubilisation efficiency of the babchi oil was checked in distilled water and found enhanced by 4.95 times with optimized β-cyclodextrin nanosponges. The cytotoxicity study was carried out by MTT assay using HaCaT cell lines. A significant improvement in photostability of essential oil was also observed by inclusion in nanosponges. Lastly, the optimized formulation was tested for antibacterial activity using Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Hence, encapsulation of BO in nanosponges resulted in efficacious carrier system in terms of solubility, photostability as well as safety of this oil along with handling benefits.
ARTICLE | doi:10.20944/preprints201805.0254.v1
Online: 18 May 2018 (05:21:32 CEST)
The patterns of food consumption in general and those of meat, in particular, are constantly changing. These changes are due not only to socio-economic and cultural trends that affect the whole society but also to the specific lifestyles of consumer groups. Due to the importance of consumer lifestyle, the objectives of this study were i) to identify the profiles of lamb meat consumers according to their orientation toward convenience, as defined by their eating and cooking habits; ii) to characterize these profiles according to their socio-economic characteristics and their preferences regarding the intrinsic and extrinsic quality signals of lamb meat; and iii) to analyze the willingness to pay for lamb confit. In this study, four types of consumers have been differentiated according to their lifestyles related to lamb consumption. These groups, due to their characteristics, could be called "Gourmet", "Disinterested", "Conservative" and "Basic". The Gourmet group has characteristics that make it especially interesting to market a product such as lamb confit; however, this group is unaware of this product. Therefore, a possible strategy to expand the commercialization of light lamb and the confit product would be guided marketing to this niche market.
ARTICLE | doi:10.20944/preprints201712.0028.v1
Online: 4 December 2017 (17:33:46 CET)
Oil revenues and external debt might have stimulated economic growth in the oil exporting countries via investment in capital projects. The paper estimated economic growth on oil revenues and external debt after controlling public investment and population growth over the period 1970-2015. Following the confirmation of the order of integration, our analysis is based on autoregressive distributed lag bound testing to cointegration approach. The key findings are that oil revenues and public investment contributes to Nigeria’s economic growth. However, our findings also indicate that external debt and population growth retards growth. The study suggests that minimizing fiscal deficits and unnecessarily foreign loans by creating tax avenues through the development of the non-oil sectors would reduce the dependency syndrome on a single commodity (oil) in Nigeria.
ARTICLE | doi:10.20944/preprints201703.0137.v1
Subject: Materials Science, Polymers & Plastics Keywords: waste cooking oil; phthalic anhydride; copolymerization; microwaves
Online: 17 March 2017 (07:36:52 CET)
Solvent free copolymerization of epoxides derived from fatty acid esters of waste cooking oil with phthalic anhydride using (salen)CrIII Cl as catalyst and n-Bu4NCl/DMAP as co-catalyst was carried out for the first time under microwave irradiation, where reaction time was reduced from number of hours to minutes. The polyesters were obtained with molecular weight (Mw = 3084-6740 g/mol) and dispersity values (D = 1.18-1.92), when (salen)CrIII Cl/n-Bu4NCl was used as catalysts. While in case of DMAP as a co-catalyst, polyesters with improved molecular weight (Mw = 5537-6925 g/mol) and narrow dispersity values (D = 1.07-1.28) were obtained even at reduced concentrations of (salen)CrIII Cl and DMAP. The obtained products were characterized and evaluated by attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR), proton nuclear magnetic resonance (1H-NMR) spectroscopy, gel permeation chromatography (GPC) and thermogravimetric analysis (TGA) Techniques.
ARTICLE | doi:10.20944/preprints201812.0201.v1
Subject: Mathematics & Computer Science, Probability And Statistics Keywords: Bayesian Vector Autoregression (BVAR), Modeling, Forecasting, Gross Domestic Product (GDP), Economic Growth, Revenue, Oil sector, Non-oil Sector
Online: 17 December 2018 (15:56:09 CET)
The present reality about the Nigerian economy calls for investment and development in the non-oil sector. This becomes necessary as a result of fall in the oil price in the global market. This paper examined the Bayesian Vector Autoregression (BVAR) modeling and forecasting of the dynamic interrelationship between Economic growth and revenue from the oil and non-oil sectors in Nigeria. To achieve this, annual data on Gross Domestic Product (GDP), revenue from oil and non-oil sectors were collected from Central Bank of Nigeria (CBN) bulletin, the sample from 1981 to 2008 was used for analysis, while sample from 2009 to 2014 was used for model validation. Six (6) versions of Sims-Zha BVAR models were compared for out-of-sample forecast, the result revealed the superiority of the BVAR6 model over the other BVAR models. Lastly, evidence from the decomposition forecast errors revealed that revenue of oil sector contributed 7.69% to GDP while revenue from non-oil sector contributed 0.12% to GDP in Nigeria. This paper therefore recommended that the present government should encourage investment that is geared toward development in the non-oil sector, of which it has the capacity to improve the Economic growth of the Nigerian economy.
ARTICLE | doi:10.20944/preprints202107.0021.v1
Subject: Materials Science, Biomaterials Keywords: paper electronics; strain gauge; sensor; low-cost electronics; van der Waals materials; tungsten disulfide WS2
Online: 1 July 2021 (11:27:41 CEST)
Environmentally friendly and low-cost sensors are needed for the next generation disposable electronics applications. Given its low-cost, availability and biodegradability, paper-based devices are a very promising. Here we demonstrate the fabrication of a tungsten disulphide (WS2) strain sensor on standard copy paper. The WS2 is deposited through direct abrasion of WS2 powder against the paper surface making the fabrication of the device low-tech and cost effective. The fabricated strain gauge devices present gauge factors up to ~70 for strains in the ± 0.5 % range. These values are ~ 9 times larger than that obtained on devices with the same geometry but using a graphite film instead a WS2 as a sensitive material. We demonstrate the potential of these WS2-on-paper strain gauges by integrating them directly on a paper cantilever to sense mass and forces. We show how this very simple device can detect sub-milligram masses. Moreover, we also demonstrate the capability of transducing motion in mechanical resonators by gluing a WS2-on-paper strain gauge on their surface.
ARTICLE | doi:10.20944/preprints202104.0358.v1
Subject: Arts & Humanities, Anthropology & Ethnography Keywords: parametric design, paper in architecture, temporary architecture, pop-up structures, membrane structures, isogeometric analysis, fabrication
Online: 13 April 2021 (13:17:11 CEST)
Temporary pavilions play an important role as experimental fields for architects, designers and engineers, apart from providing exhibition spaces. Novel structural and formal solutions applied in pavilions also can give them unusual appearance that attracts eyesight of spectators. In this article authors explore the possibility of combination of structural novelty, visual attractiveness and low-cost by a design and construction of a temporary pavilion. For that purpose, an innovative structural system and design approach was applied, i.e. membrane structure designed in Rhino and Grasshopper environments with the use of Kiwi!3D IsoGeometric analysis tool. The designed pavilion, named Obverse/Reverse, was built in Opole, Poland, for the occasion of World Architecture Day in July 2019. Design and construction was performed by the authors in cooperation with students’ organisation Humanisation of Urban Environment from the Faculty of Architecture Wroclaw University of Science and Technology. The Rresultant pavilion proved the possibility of obtaining a low-budgets but visually attractive architectural solution with the adaption of parametrical design tools and some scientific background with innovative structural systems.
ARTICLE | doi:10.20944/preprints201808.0001.v1
Subject: Social Sciences, Library & Information Science Keywords: normalized indicators; correlation analysis; Source Normalized Impact per Paper; SNIP; Field-Weighted Citation Impact; FWCI
Online: 1 August 2018 (05:57:55 CEST)
Recently, more and more countries are entering the global race for university competitiveness. On the one hand, global rankings are a convenient tool for quantitative analysis. On the other hand, their indicators are often difficult to quickly calculate, they often contradict each other. We thought about using widely available indicators for a quick analysis of the University's publication strategy. We opted for the normalized citation indicators available in SciVal analytical tool, i.e. Source Normalized Impact per Paper (SNIP) and Field-Weighted Citation Impact (FWCI). We have demonstrated the possibility of applying the correlation analysis to the impact indicators of a document and a journal on the sample of the social and humanitarian fields at Peoples' Friendship University of Russia. Particular attention was paid to the application of the results in practice.
ARTICLE | doi:10.20944/preprints202209.0191.v1
Subject: Biology, Plant Sciences Keywords: Acinetobacter baumannii; Etlingera elatior; antibiofilm activity; essential oil
Online: 14 September 2022 (04:37:05 CEST)
The current study investigates the antibiofilm properties of essential oil extracted from the Flower of a Zingiber plant used in traditional medicines. EO from Etlingera elatior (Jack) R. M Smith tested against one of the critical nosocomial pathogens, Acinetobacter baumannii. The antibiofilm studies of Flower essential oil (FEO) by crystal violet staining method exhibited maximum inhibition of 80% at a concentration of 0.7% oil. The biochemical assays and microscopic analysis showed that the FEO significantly reduced extracellular polymeric substance production. Furthermore, FEO reduced the survival rate of A. baumannii in human blood. The chemical composition of extracted FEO was analyzed by Gas chromatography- Mass spectrometry. Dodecanal, 1-dodecanol, and alpha-pinene were identified as the major compounds. Concerning previous research, our study is the first investigation of the antibiofilm property of E. elatior flower oil. More detailed studies are required to identify the compound responsible for biofilm inhibition and its mode of action against A. baumannii biofilms.
REVIEW | doi:10.20944/preprints202108.0386.v1
Subject: Life Sciences, Biotechnology Keywords: Clove essential oil; biological activity; chemical composition, extraction.
Online: 18 August 2021 (14:19:49 CEST)
Clove (Syzygium aromaticum L. Myrtaceae) is an aromatic plant widely cultivated in tropical and subtropical countries, rich in volatile compounds and antioxidants such as eugenol, β-caryophyllene, and α-humulene. Clove essential oil has received considerable interest due to its wide application in the perfumery, cosmetic, health, medical, flavoring, and food industries. Clove essential oil has relevant biological activities to human health, including antimicrobial, antioxidant, and insecticide. This review describes the effect of the extraction method (hydrodistillation, steam distillation, ultrasound-assisted extraction, microwave-assisted extraction, cold pressing, and supercritical fluid extraction) on the chemical composition of essential oil and its correlation with their biological activities. Likewise, are summarized the main compounds and their reported biological activities. Furthermore, the main applications in clove essential oil in the food industry are presented. Finally, this review presents the new biological activities such as anti-inflammatory, analgesic, anesthetic, antinociceptive and anticancer, which are beneficial for human health. This review aims to compile the effect of different methods of extracting clove essential oil on chemical composition, food applications, as well as a current description of biological activities of interest to human health. Biological activities have increased interest in research into this essential oil and its future applications in the food or pharmaceutical industry.
ARTICLE | doi:10.20944/preprints202108.0092.v1
Subject: Biology, Anatomy & Morphology Keywords: petroleum; metagenomics; core microbiota, functional potential, oil fields
Online: 3 August 2021 (15:29:57 CEST)
Microorganisms inhabiting subsurface petroleum reservoirs are key players in biochemical transformations. The interactions of microbial communities in these environments are highly complex and still poorly understood. This work aimed to assess publicly available metagenomes from oil reservoirs and implement a robust pipeline of genome-resolved metagenomics to deci-pher metabolic and taxonomic profiles of petroleum reservoirs worldwide. Analysis of 301,2 Gb of metagenomic information derived from heavily flooded petroleum reservoirs in China and Alaska to non-flooded petroleum reservoirs in Brazil enabled us to reconstruct 148 MAGs of high and medium quality. At the phylum level, 74% of MAGs belonged to bacteria and 26% to ar-chaea. The profiles of these MAGs were related to the physicochemical parameters and recovery management applied. The analysis of the potential functional core in the reservoirs showed that the microbiota was specialized for each site, with 31.7% of the total KEGG orthologies annotated as functions (1,690 genes) common to all oil fields, while 18% of the functions were site-specific, i.e., present only in one of the oil fields. The oil reservoirs with lower level of intervention were the most similar to the potential functional core, while the oil fields with longer history of water in-jection had greater variation in functional profile. These results show how key microorganisms and their functions respond to the distinct physicochemical parameters and interventions of the oil field operations such as water injection and expand the knowledge of biogeochemical trans-formations in these ecosystems.
ARTICLE | doi:10.20944/preprints202108.0073.v1
Subject: Chemistry, Analytical Chemistry Keywords: Ultrasonic; Carbon dioxide; Enhanced oil recovery; Unconventional reservoirs
Online: 3 August 2021 (11:25:12 CEST)
CO2 enhanced oil recovery (EOR) has been proven its capability to explore the unconventional tight oil reservoirs and potential for geological carbon storage. Meanwhile, the extremely low permeability pores exaggerate the difficulty CO2 EOR and geological storage processing in the actual field. This paper initiates the ultrasonic-assisted approach to facilitate the oil-gas miscibility development and finally contribute to unlock more tight oils. First, the physical properties of crude oil with and without ultrasonic treatments were experimentally analysed through gas chromatography (GC), Fourier-transform infrared spectroscopy (FTIR) and viscometer. Second, the oil-gas minimum miscibility pressures (MMPs) were measured from the slim-tube test and the miscibility developments with and without ultrasonic treatments were interpreted from the mixing-cell method. Third, the nuclear-magnetic resonance (NMR) assisted coreflood tests were conducted to physically model the recovery process in porous media and directly obtain the recovery factor. Basically, the ultrasonic treatment (40KHz and 200W for 8 hours) was found to substantially change the oil properties, with viscosity (at 60°C) reduced from 4.1 to 2.8mPa·s, contents of resin and asphaltene decreased from 27.94% and 6.03% to 14.2% and 3.79%, respectively. The FTIR spectrum shows the unsaturated C-H bond, C-O bond and C≡C bond in macromolecules were broken from ultrasonic, which caused the macromolecules (e.g., resin and asphaltenes) to be decomposed into smaller carbon-number molecules. Accordingly, the MMP was determined to be reduced from 15.8 to 14.9MPa from the slim-tube test and the oil recovery factor increased by over 10%. This study reveals the mechanisms of ultrasonic-assisted CO2 miscible EOR in producing tight oils.
ARTICLE | doi:10.20944/preprints201904.0060.v1
Subject: Materials Science, Nanotechnology Keywords: oil, nanocomposite membranes, PVDF-TrFE, photoreactor, and sunlight.
Online: 5 April 2019 (11:48:43 CEST)
Production of wastewater related to the oil and gas industries is increasing over the years. The compounds found in industrial wastewater typically show high toxicity, and in this way, they have become a primary environmental concern. Several techniques have been applied in industrial effluents remediation. In spite of the efforts, these techniques are yet ineffective to treat oily wastewater before it can be discharged safely to the environment. Membrane technology is an attractive approach to treat oily wastewater. This is dedicated to the immobilisation of TiO2 nanoparticles on poly (vinylidene fluoride–trifluoro ethylene) (PVDF-TrFE) porous matrix by solvent casting. Membranes with interconnected pores with an average diameter of 60 micrometres and the contact angle of 97°, decorated with TiO2 nanoparticles, are obtained. The degradation of oily wastewater demonstrated the remarkable photocatalytic efficiency of the nanocomposite membranes: under sunlight irradiation for 7 hours, colourless water was obtained. These results show the suitability of TiO2/P(VDF–TrFE) nanocomposite for photocatalytic applications for oily wastewater remediation.
ARTICLE | doi:10.20944/preprints201904.0019.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: Castor oil; Ascorbic acid; Bowel preparation; Polyethylene glycol
Online: 1 April 2019 (13:42:38 CEST)
Our aim was to evaluate efficacy and safety of 30mL CaO alone or plus Asc in bowel preparation before colonoscopy. Two hundred and forty six patients were allocated randomly to ingest 2L PEG with 30mL CaO, 1L PEG with 30mL CaO plus 5g Asc, or 3L PEG. We used Boston Bowel Preparation Scale (BBPS) to evaluate bowel preparation efficacy. We also determined other outcomes such as procedure time, polyp or adenoma detection rate and adverse events (AEs). Of 282 patients recruited, 36 were excluded. Groups were matched for baseline characteristics except weight (P = 0.020) and body mass index (BMI) (P = 0.003). Patient’s satisfaction were higher in 2L PEG-CaO (P = 0.016) and 1L PEG-CaO-Asc groups (P = 0·017). Patients’ compliance was 67.5%, 71.4% and 80.5% in 3L PEG, 2L PEG-CaO and 1L PEG-CaO-Asc groups (P = 0.014). Adequate bowel preparation rate was 75%, 78.57% and 53.66% in 3L PEG, 2L PEG-CaO and 1L PEG-CaO-Asc groups (P = 0.021). There were no differences in terms of remaining outcomes. Despite an increase in patients’ satisfaction and compliance, 1L PEG-CaO-Asc significantly decreased adequate bowel preparation rate. However, 2L PEG-CaO improved the patients' satisfaction and compliance and increased adequate bowel preparation rate.
ARTICLE | doi:10.20944/preprints201902.0219.v1
Subject: Engineering, Other Keywords: Lycopene, Blakeslea trispora, fermentation, vegetable oil, orange peel
Online: 25 February 2019 (08:54:39 CET)
The production of lycopene from different substrates by Blakeslea trispora in fermentation was investigated. Lycopene productions from 4 and 6 % glucose (pH 6.5) in shake flask fermentation were 77.7 and 28.1 mg L-1. A maximum lycopene concentration of 944.8 mg L-1 was detected with 4 % glucose supplemented with 1.0 % sunflower oil in fermentor studies. Zygospores of B. trispora are the morphological forms, which are responsible for the production of the lycopene. The highest level of zygospores was correlated with the highest amount of intracellular lycopene in the total biomass dry weight. The media containing only orange peel (1 %) gave a 4.9 mg L-1 lycopene production in a fermentor. The presence of oils as substrates resulted in enhanced mold growth and subsequent higher lycopene production. Substrates containing linoleic acid compounds led to high lycopene production. The data showed that the biosynthesis of lycopene starts in most cases simultaneously in the early growth phase even in trace amounts and the amount of lycopene formation increased continuously from 2 to 7 days.
ARTICLE | doi:10.20944/preprints201811.0167.v1
Subject: Engineering, Mechanical Engineering Keywords: Condition monitoring; Predictive maintenance; Oil analysis; Urban buses.
Online: 7 November 2018 (14:36:00 CET)
The paper presents a case study and a model for condition monitoring of Diesel engines’ oil of urban buses, through the accompaniment of the evolution of its degradation, with the objective to implement a predictive maintenance policy. Along time, because the usage, there is some decay in the lubricant properties. However, in normal functioning conditions, the lubricants properties, at the time the manufacturers recommend its changing, regardless of they are within the safety limits. Then, based on the accompaniment of the lubricants’ oil condition, the intervals of oil replacement can be enlarged what implies the availability increasing and the corresponding production increasing of the equipment. The model presented in this paper shows its potential to be spread to other types of equipment and organisations that want can implement similar maintenance policies, to achieve the best availability based on the real equipment health conditioning conditions
ARTICLE | doi:10.20944/preprints201809.0505.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: renewable energy, microwave, free fatty acid, crude oil
Online: 26 September 2018 (10:31:20 CEST)
A novel method proposed in the production of Calophyllum inophyllum biodiesel has been investigated experimentally. In this study, we report the results of biodiesel processing with electromagnetic induction technology. The method used is to compare the results of Calophyllum inophyllum biodiesel processing between conventional, microwave and electromagnetic induction. The degumming, transesterification, and esterification process of the 3 methods are measured by stopwatch to obtain time comparison data. Characteristics of viscosity, density, and Fatty Acid Metil Ester (FAME) were obtained from testing of a Gas Chromatography-mass Spectrometry (GCMS) at the Polytechnic Chemistry Laboratory of the State of Malang. The results show that the biodiesel produced by this method satisfies the biodiesel standards and their characteristics are better than the biodiesel produced by conventional and microwave methods. The electromagnetic induction method also offers a fast and easy route to produce biodiesel with the advantage of increasing the reaction rate and improving the separation process compared to other methods. This advanced technology has the potential to significantly increase biodiesel production with considerable potential to reduce production time and costs.
ARTICLE | doi:10.20944/preprints201809.0391.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: cigarette filter; superhydrophobic; highly selective; absorbent; oil spillage
Online: 19 September 2018 (21:36:11 CEST)
Ecological and environmental damage caused by oil spillage has attracted great attention. Used cigarette filter (CF) has also caused negative environmental consequences. Converting CF to economical materials is a feasible way to address these problems. In this study, we demonstrate a simple method for production of a highly hydrophobic absorbent from CF. CF was modified by using different volume ratios of octadecyltrichlorosilane and methyltrimethoxysilane. When the volume ratio was 3:2, the modified CF had the high water contact angle of 155°. It could selectively and completely absorb silicone oil from an oil-water mixture and showed a good absorption capacity of 38.3 g/g. The absorbed oil was readily and rapidly recovered by simple mechanical squeezing, and it could be reused immediately without any additional treatments. The as-obtained superhydrophobic modified CF retained an absorption capacity of 80% for pump oil and 82% for silicone oil after 10 cycles. The modified CF showed good elasticity in the test of repeated use. The present study provides novel design of a functional material for development of hydrophobic absorbents from used CF via a facile method toward oil spillage cleanup as well as a new recycling method of CF to alleviate the environmental impact.
ARTICLE | doi:10.20944/preprints201809.0338.v1
Subject: Chemistry, Food Chemistry Keywords: Ocimum spp.; essential oil; aromatic profiles; Thai food
Online: 18 September 2018 (09:47:32 CEST)
The research objectives of this study are to analyse the volatile compositions of different basil types available in Thai markets and to descriptively determine their aromatic qualities. Essential oils were hydro-distillated from fresh leaves of 2 Holy basil (Ocimum sanctum) varieties namely, white and red and other basil species, including Tree basil (O. gratissimum), Sweet basil (O. basilicum var. thyrsiflorum) and Lemon basil (O. citriodorum). Oil physicochemical characteristics and volatile chromatograms from Gas Chromatography-Mass Spectrometry (GC-MS) were used to qualitatively and quantitatively describe the chemical compositions. Methyl eugenol, estragole and eugenol were among the major chemicals found in the essential oils of these basil types. Classification by Principal Component Analysis (PCA) advised that these Ocimum spp. samples are grouped based on either the distinctive anise, citrus aroma (estragole, geranial and neral) or spice-like aroma (β-methyl eugenol, caryophyllene and α-cubebene). The essential oil was also used for descriptive sensorial determination by five trained panelists, using the following developed terms: anisic, citrus, herb, spice, sweet and woody. The panelists were able to differentiate essential oil of white Holy basil from red Holy basil based on the intensity of the anisic attribute, while the anise and citrus scents were detected as dominant in the Lemon basil, Tree basil and Sweet basil essential oils. The overall benefit from this research was the elucidation of aromatic qualities from Thai common Ocimum species in order to assess their potential as the raw materials for future food research and development.
ARTICLE | doi:10.20944/preprints201805.0481.v1
Subject: Engineering, Automotive Engineering Keywords: waste mineral oil; Mn additive; engine performance; emission
Online: 31 May 2018 (13:27:48 CEST)
The heat values of waste mineral oils are equal to the heat value of the fuel oil. However, heat value alone is not sufficient for the use of waste mineral oils. as fuel. However, the critical physical properties of fuels such as density and viscosity need to be adapted to the system in order to be used. In this study, the engine oils used in the first 10,000 km of the vehicles were used as waste mineral oil. An organic-based Mn additive was synthesized to improve the properties of the waste mineral oil. It was observed that mixing the Mn additive with the waste mineral oil at different doses (4, 8, 12 and 16 ppm) improves the viscosity of the waste oil and the flash point. The resulting fuel was evaluated for emission using different loads in a 5 kW capacity generator to compare the fuel with standard diesel fuel and to determine the effect of Mn addition. In the experimental study, it was observed that the emission characteristics of the fuel obtained from waste mineral oil were worse than diesel fuel, but some improvement with Mn addition. As a result, we found that the use of waste mineral oils in engines in fuel standards was not appropriate, but may be improved with additives.
CASE REPORT | doi:10.20944/preprints201712.0044.v1
Subject: Engineering, Energy & Fuel Technology Keywords: reciprocating pump; oil station; pipeline; vibration; pressure pulsation
Online: 7 December 2017 (14:46:23 CET)
Due to the periodic movement of the piston in the reciprocating pump, the fluid will cause pressure pulsation, and the vibration of the pipeline will lead to instrument distortion, pipe failure and equipment damage. Therefore, it is necessary to study the vibration phenomena of the reciprocating pump pipeline based on the pressure pulsation theory. This paper starts from the reciprocating pump pipe pressure pulsation caused by fluid, pressure pulsation in the pipeline and the excited force is calculated under the action of the reciprocating pump. Then, the numerical simulation model is established based on the pipe beam model, and the rationality of the numerical simulation method is verified by the indoor experiment. Finally, a case study is taken as an example to analyze the vibration law of the pipeline system, and proposed the stress reduction and vibration reduction measures. The main conclusions are drawn from the analysis: (1) Excited force is produced in the bend or tee joint, and it can also influence the straight pipe in different levels; (2) In this pipeline system, the pump discharge pipe has a larger vibration amplitude and lower natural frequency; (3) The vibration amplitude increases with the pipe thermal stress, and when the oil temperature is higher than 85°C, it had a greater influence on the vertical vibration amplitude of the pipe.
ARTICLE | doi:10.20944/preprints202212.0029.v1
Subject: Social Sciences, Accounting Keywords: financial ratios; cross section; oil and gas trading industry
Online: 2 December 2022 (01:51:17 CET)
This research was conducted with the aim of knowing how to compare the financial performance of the oil and gas trading industry with cross-sectional analysis techniques. The type of research conducted in this research is qualitative research with research objects at several companies, namely PT Radiant Utama Interinsco Tbk, PT Elnusa Tbk, PT AKR Corporindo Tbk, and PT Aneka Gas Industri Tbk. The data used in this study comes from secondary data, namely the internet in the form of company financial reports for the 2019-2021 period obtained from the Indonesia Stock Exchange. The results of this study indicate that PT Radiant Utama Interinsco Tbk has the best financial performance on inventory turnover ratio and average age, PT Elnusa Tbk has good inventory performance on current ratio, quick ratio, DAR, and DER., PT AKR. Corporindo Tbk has performed well on the ratios of TIE, FCC, Dividend Payout, Dividend Yield, and PER. PT Aneka Gas Industri Tbk has performed well on the ratio of Receivables Turnover Ratio and Average Age of Receivables.
ARTICLE | doi:10.20944/preprints202207.0105.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: Melaleuca armillaris; essential oil; erythromycin; Staphylococcus aureus; synergism; mastitis
Online: 7 July 2022 (04:05:55 CEST)
Staphylococcus aureus frequently causes subclinical mastitis around the world with high impact in milk industry and public health. Essential oils (EO) are recognized antimicrobials that can be synergistic with antibiotics. The main objective of this study was evaluating the essential oil (EO) of Melaleuca armillaris as an adjuvant of erythromycin (ERY) for the alternative treatment of bovine mastitis caused by S. aureus. The Minimum Inhibitory and Bactericidal Concentrations (MIC and MBC) of EO, ERY, and its combinations were established against S. aureus at different pHs (7.4, 6.5 and 5.0), emulating extra and intracellular conditions. Sensible (N=3) and resistant (N=3) strains to ERY and S. aureus ATCC 29213 as control were used. Math models were applied to described the antibacterial activity of EO and combinations EO-ERY. The EO was bactericidal against all the strains independently of the pH with a slightly improvement in acid conditions. The synergism between EO and ERY was estimated by the Fractional Inhibitory Concentration Index (FIC) and by mathematical modeling of the bacterial killing data. Synergism was observed with ERY, where combinations had bactericidal activity also even with pH modification. M. armillaris EO is an interesting adjuvant for ERY, being a promissory option for further analysis of intracellular efficacy against S. aureus.
ARTICLE | doi:10.20944/preprints202205.0190.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: adsorbent; palm oil; central composite design; bleaching; snail shell
Online: 13 May 2022 (10:40:35 CEST)
Agricultural wastes have posed as a treat to the environment over the years and they are found in large quantities due to domestic and industrial utilization of such materials in under developed and developing countries. The inability to recycle this waste has led to researches on how to use them in carrying out productive industrial activities. The aim of this study is to use Central Composite Design (CCD) to optimize the bleaching effects by snail shell as adsorbents on crude palm oil. The predictive ability of the model was close to accurate using MINITAB 19 software with the design application for the process simulation for % FFA yield to have 75.856% for experimental and 77.587% for predicted yield with just 1.731% residual. The saponification value increased with adsorption, and it indicates that palm oil can be used for soap making.
ARTICLE | doi:10.20944/preprints202108.0266.v1
Subject: Earth Sciences, Environmental Sciences Keywords: oil palm; modeling; climate; temperature; rainfall; sunshine; wind; humidity
Online: 11 August 2021 (15:44:03 CEST)
Oil palm is one of the most important crops in Malaysia. Lately, the production of oil palm has been reduced due to a variety of factors, including the weather and climate. Temperature, wind speed, relative humidity, sunshine, and rainfall distribution all have an impact on palm tree growth and development, which in turn has an impact on oil palm production. This paper aims to investigate the effects of some weather elements (temperature, wind speed, relative humidity, sunshine, and rainfall) on oil palm production in Peninsular Malaysia. Data were analyzed using the Statistical Package for Social Sciences (SPSS 20.0 version), with descriptive statistics, and multiple linear regression (MLR). The MLR model determined the strength of the relationship between oil palm yield (dependent variable) and the changing variables of temperature, sunshine, wind speed, relative humidity, and rainfall (independent variables). The findings revealed that temperature, wind speed, relative humidity, sunshine, and rainfall have a low impact on oil palm production and yield turnover. The R2 value of 0.202 shows that the independent variables explained only 20.2% of the fluctuation in palm oil production. The study recommends working within an integrated approach involving scientific research, planting, improving variety, improving regional academic leadership, and engaging private and public stakeholders, emphasized collaborative efforts with researchers in consumer countries, and strengthening the capacity of growers to best agroecological practices.
REVIEW | doi:10.20944/preprints202106.0500.v1
Subject: Life Sciences, Biochemistry Keywords: anticancer; antimicrobial; antioxidants; cancer signalling; citral; Cymbopogon; essential oil
Online: 21 June 2021 (10:31:35 CEST)
The prominent cultivation of lemongrass relies on the pharmacological incentives of its essential oil. The lemongrass essential oil (LEO) has a significant amount of citral (mixture of geranial and neral), isoneral, isogeranial, geraniol, geranyl acetate, citronellal, citronellol, germacrene-D, and elemol in addition to numerous other bioactive compounds. These components confer various medicinal activities to LEO including antifungal, antibacterial, antiviral, anticancer, and antioxidant properties. These attributes are commercially exploited in pharmaceutical, cosmetics, and food preservations industries. Furthermore, the employment of LEO in the treatment of cancer opens a new vista in the field of therapeutics. Although different LEO components have shown promising anticancer activities in vitro, these effects have not been assessed yet in humans. Further studies on the anticancer mechanisms exerted by lemongrass components are required. The present review intends to provide a timely discussion on the relevance of lemongrass extracts in cancer and health treatment, and in food industry applications.
Subject: Chemistry, Analytical Chemistry Keywords: Functional Food; Sauce; Olive Oil; Olive Leaf; Polyphenolic Compounds
Online: 23 April 2021 (12:02:07 CEST)
This study was carried out in three phases. During the first stage, the physicochemical properties of French sauce prepared from different blends of soybean and olive oils were evaluated. In the second stage, the oxidative stability of the optimum sauce sample from the first stage enriched with various amounts of olive leaf polyphenolic extract (OLE) (obtained via ultrasound-assisted extraction) was investigated over 90 days of storage. During the third stage, the microbiological and sensory properties of the samples containing the optimum amounts of OLE, as a substitution for the synthetic preservatives, were studied. According to the results, addition of olive oil at higher levels (75 and 100%) could affect the physicochemical properties of the sauce as compared to the control sample. It was also found that the addition of olive oil (up to 50%) would not significantly impact the sauce properties. Regarding the OLE enrichment in the samples, it was found that high levels of OLE could improve the oxidative stability of the samples. Based on the results of the experiments in the third phase, it was found that OLE could be used as a preservative instead of the commercial ones. Overall, this study suggests the potential use of olive oil and olive leaf extract in the preparation of French sauce to boost its nutritional value and its stability.
ARTICLE | doi:10.20944/preprints202012.0203.v1
Subject: Engineering, Automotive Engineering Keywords: hexane-isopropanol extraction; omega-3 fish oil; Atlantic salmon
Online: 8 December 2020 (14:55:54 CET)
Atlantic salmon (Salmo Salar) is one of the fish species that rich in omega-3 fatty acids. Consumption of omega-3 fatty acids can lower down the risk of cardiovascular disease and coronary heart disease. The extraction of omega-3 fish oil from Atlantic salmon by using hexane and isopropanol was conducted in this research. Response Surface Methodology (RSM) was used to study the impact of parameters which were temperature (50-90°C), centrifuge speed (1000-3000rpm) and solvent ratio of hexane to isopropanol (0.5-1.5) to the percentage of oil yield. The results obtained shows that 15.23%± 0.61 of oil yield from Atlantic salmon under an optimum condition of 70°C, 3000 rpm and solvent ratio of hexane to isopropanol of 1.5. The acid value, peroxide value and p-anisidine value of the fish oil obtained were 7.48 mg KOH/g, 1.94 meq/kg and 5.56 respectively which were all within the acceptable limit which stipulated by Global Organization for EPA and DHA (GOED) and Food and Agricultural Organization of the United Nations (FAO). The FTIR analysis proved the presence of alkane and carboxylic acid in the fish oil. Furthermore, GC-MS analysis showed that the fish oil contains higher monounsaturated fatty acids (MUFA) contents followed by polyunsaturated fatty acids (PUFA) and 4.5525% of total omega-3 fatty acids.
ARTICLE | doi:10.20944/preprints202011.0430.v1
Subject: Social Sciences, Accounting Keywords: oil price; maritime freight rate; asymmetry; dependence; copula; decomposition
Online: 16 November 2020 (15:33:46 CET)
Changes in crude oil price affect the shipping freight market in three different channels. This study explores the dependence structure between oil prices and maritime freight rates to identify the strongest channel. Therefore, it investigates the relationship between oil prices and three major maritime freight rates; the Baltic Dry Index (BDI), the Baltic Dirty Tanker Index (BDTI), and the Baltic Clean Tanker Index (BCTI). We employ the decomposition method, not studied in the existing literature. The copula approach identifies the time-varying effects and asymmetry in the tail dependence structure between oil prices and freight rates. The main results of this analysis are as follows. The decomposed components display different conditional dependence patterns, and asymmetry is revealed in the upper and lower tail dependence. In the long run, we find more dependence in extreme periods like the financial crises. In short-run fluctuations, we find the dependence increases in an economic boom. The implications of the results suggest that dependence can vary over time and may change depending on extreme events, implying that the complementary strategies of the long run and short run should be different.
ARTICLE | doi:10.20944/preprints201909.0121.v1
Subject: Life Sciences, Biochemistry Keywords: Tomato borer; essential oil; GC-MS profile; larvicidal effects
Online: 11 September 2019 (13:21:03 CEST)
This study aimed to determine the Gas Chrommatography (GC)-Mass Spectrometry (MS) profiles and insecticidal activity of essential oils (EOs) from Thymus vulgaris (Thyme) and Cymbopogon citratus (Lemongrass) against the invasive and devastating pest, Tuta absoluta (T. absoluta) through contact and fumigation routes. We found out that thyme oil was predominantly constituted of Thymol (22.16%), α-Pinene (15.35%) and p-Cymene (13.54%) whilst Neral (21.41%), Geranial (21.36%) and β-Myrcene (9.74%) were the major constituents of lemongrass oil. Lemongrass oil exhibited higher insecticidal efficiency irrespective of application mode with 50% lethal dose (LD50) values of 35.8 and 72.2 µL.L-1air on contact and fumigation routes, respectively. Lemongrass oil also lengthened pupal duration at all tested doses irrespective of application routes. The overall responses of Lemongrass oil surpassed that of the reference insecticide (Lynx®: Lambda-cyhalothrine; Acetamipride). Thus, the recorded data clearly showed the acute and long-term insecticidal effects of the studied EOs, though a greenhouse and open field trials are required prior to the validation of this approach as remediation measure for Integrated Pest Management (IPM) for tomato borer control in Cameroon and elsewhere.
Subject: Chemistry, Food Chemistry Keywords: waste cooking oil; volatiles; 1H NMR; mass spectrometry; prototype
Online: 16 April 2019 (11:19:15 CEST)
Samples of sunflower Waste Cooking Oils (WCOs) subjected to several cycles of frying were treated with water under four different combinations of temperature and pH. The variation of the chemical composition of the oil samples was monitored through headspace Solid-Phase Microextraction (HS-SPME) coupled with gas-chromatographic technique (GC), 1H NMR spectroscopy and ESI+ mass spectrometry measurements. The possibility to modify the chemical composition of the recycled vegetable oil by tuning the water treatment parameters was exploited for the designing of a mini-plant for the production of bio-lubricants. A full description of the proposed prototype is also reported.
ARTICLE | doi:10.20944/preprints201812.0225.v1
Subject: Engineering, Energy & Fuel Technology Keywords: pipeline; transportation; trailing oil; CFD; dead-leg; modified formula;
Online: 18 December 2018 (16:21:13 CET)
Trailing oil is the tail section of contamination. There are two main reasons for the formation of trailing oil, one is the effect of laminar flow boundary layer, the other is the outflow of the preceding batch remained in the dead-legs. In the batch transportation of refined oil, under the action of viscous force, the preceding batch forms laminar boundary layer near the pipe wall and stays on the pipe wall, resulting in the phenomenon of contamination trailing and formation of trailing oil. When oil passes through the valve chamber of the oil transportation station, dead-leg will be formed. Due to gravity and convection diffusion, preceding batch flowing from dead-legs will form trailing oil in the pipeline. The phenomenon of trailing oil exists in the process of batch transportation, which will have an effect on the quality of oil. In this paper, Reynolds time-averaged method is used to simulate turbulence.Computational Fluid Dynamics(CFD) software is used to simulate different flow rates and bypass lengths to obtain contamination-related experimental data.Matlab software is used to perform multi-nonlinear regression for the oil substitution time, the length of the bypass and the flow rate. The formula for calculating the length of the trailing oil produced by the dead-leg is obtained. The modified formula for calculating the length of the contamination is obtained by combining the existing formula for calculating the length of the contamination.
COMMUNICATION | doi:10.20944/preprints201811.0380.v1
Subject: Engineering, Energy & Fuel Technology Keywords: bio-oil; biomass conversion; carbide catalyst; ketonization; doped carbides
Online: 16 November 2018 (07:10:50 CET)
Carboxylic acids such as acetic acid and propionic acid have been investigated as representative components for fast pyrolysis (FP) bio-oil upgrading. Selective catalytic conversion of carboxylic acids can enhance bio-refinery processing economics through catalyst preservation and process intensification. Various metal-doped molybdenum carbide bead catalysts have been synthesized and developed in this work. Our aim is to enable selective conversion of carboxylic acids. In the case of acetic acid conversion, calcium doped Mo2C beads offer the highest yield of acetone ~96% at 450 °C among undoped and Ca or Ni doped catalysts. By comparing hot gas filter with and without Ca-Mo2C catalyst tested with real FP vapors, the former showed a 36.7% reduction of acetic acid, a 37.5% reduction of small ketones in aqueous phase, and a ~50% reduction of methoxies (methoxy phenols and methoxy aromatics) in organic phase. The conversion resulted in the formation of more long chain chemicals in the organic phase, which are more amendable for downstream upgrading.
ARTICLE | doi:10.20944/preprints201809.0158.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Oil shale; Permeability; Pyrolysis; High temperature and high pressure
Online: 10 September 2018 (09:14:56 CEST)
In-situ injection of steam for heating of the subsurface is an efficient method for the recovery of oil and gas from oil shale where permeability typically evolves with temperature. We reported measurements on Jimusar oil shales(Xinjiang, China) at different temperatures to 600℃ and under recreated in situ triaxial stresses to obtain permeability evolution with temperature and stress. Permeability of tight oil shales evolves with temperature to a threshold temperature and peak temperature. The threshold temperature was subjected to triaxial stresses. For Jimusar oil shale, the threshold temperature ranges from 200℃ to 250℃ at ground stress of buried depth of 500m and from 350℃ to 400℃ at buried depth of 1000m. The peak temperature was almost not subjected to triaxial stress and the range is from 450℃ to 500℃ for all Jimusar samples. Pyrolysis plays an important role in permeability evolution and fundamentally changes permeability tendency and magnitude. At high temperature permeability exhibits a little reduction due to stress effect but still remains a high level due to pyrolysis. The above results show that oil shale mass can change from tight porous media into highly permeable media and oil & gas can easily flow through oil shale stratum.