Browse
Record Types
Records with Type: Published Article
Showing records 37668 to 37692 of 43292. [First] Page: 1 1504 1505 1506 1507 1508 1509 1510 1511 1512 Last
Influences of the Braking Effect of Ruler EMBr on Molten Steel Flow and Steel−Slag Interface Fluctuation in a Continuous Casting Mold
Lin Xu, Qun-Wu Pei, Ze-Feng Han, Jie Cui, Hong-Gang Pan, Yan-Tao Yao
February 21, 2023 (v1)
Keywords: continuous casting, electromagnetic braking, mold, molten steel flow, steel–slag interface fluctuation
Electromagnetic braking (EMBr) technology, as one of the most effective technologies in the continuous casting process, provides an effective tool for improving the internal and external defects of steel products. Specifically, the EMBr technology takes the benefit of the generation of Lorentz force to decrease flow instability, mold powder entrapment, and surface defects, if applied properly. For this purpose, to gain a clear understanding of the effect of EMBr technology on the continuous casting process, a commonly used EMBr technology, namely ruler EMBr technology, is applied in the current work to investigate the dynamic behaviors of molten steel flow and steel−slag interface fluctuation inside a slab mold. Furthermore, to obtain a desirable braking effect of the ruler EMBr technology, operational parameters including the magnetic flux density, submerged entry nozzle (SEN) depth, and magnetic pole location are numerically investigated. The results demonstrate that the braking effe... [more]
Specification and Simplification of Analytical Methods to Determine Wine Color
Marcel Hensel, Sarah Di Nonno, Yannick Mayer, Marina Scheiermann, Jörg Fahrer, Dominik Durner, Roland Ulber
February 21, 2023 (v1)
Keywords: CIE L*a*b*, cubic splines, Glories, OIV, Lagrange interpolation, Photometry, portable analysis system, Sprague interpolation, wine color
The color of wine is an important quality parameter essential for the first impression of consumers. The International Organization of Vine and Wine (OIV) recommends two methods to describe wine color: color calculation according to Glories and the determination of coordinates in the CIE L*a*b* color space. The measurement of wine color is often not feasible for winemakers because the required instrumentation is expensive and bulky. In this study, the influence of photometer settings on the calculated color was investigated based on 14 wines. Furthermore, the CIE L*a*b* and Glories system were compared using 56 red and 56 white wines. Photometer settings were found to influence the reproducibility of color determination. In addition, CIE L*a*b* system do not correlate in all wines with the Glories system and Glories probably provides less information about wine color. Using interpolation, CIE L*a*b* coordinates were calculated from single wavelength measurements taken by a small-sized... [more]
The Effect of the New Imidazole Derivatives Complexation with Betacyclodextrin, on the Antifungal Activity in Oropharyngeal Infections
Elena Lacramioara Lisa, Oana Maria Dragostin, Antoneta Dacia Petroaie, Gabriela Gurau, Alina Cristea, Alexandra Pavel, Florina Bonifate, Paul Serban Popa, Madalina Matei
February 21, 2023 (v1)
Subject: Biosystems
Keywords: antimicrobian activity, fungal infections, imidazole, ketoconazol
Ketoconazole (KZ) is a broad-spectrum drug used to treat fungal infections. Local use of ketoconazole has been associated with some side effects in healthy adults, especially local reactions, such as stinging, severe irritation, and itching. Moreover, the bioavailability of KZ after oral administration is low in tablets due to its low water solubility. In addition, oral administration of ketoconazole produces systemic exposure, associated with significant side effects, such as cholestatic and hepatocellular lesions. In an attempt to reduce hepatotoxicity, ketoconazole may be administered at the primary site of infection with cutaneous candidiasis, specifically on the skin tissue. However, the use of ketoconazole in topical dosage forms is limited by its high lipophilicity and extremely poor aqueous solubility (1 ng/mL), thus leading to the rare availability of topical dosage forms on the market. Therefore, a new approach to the effective delivery of ketoconazole to the site of infectio... [more]
Analysis of Ultrasound Signal on Reflection from a Sharp Corner Surface: Study of Selected Characteristics Deriving from Regression by Transfer Function
Vladimír Madola, Vladimír Cviklovič, Stanislav Paulovič
February 21, 2023 (v1)
Keywords: distance measurement, dynamic system, frequency analysis, transfer function, ultrasound
This article deals with the regression analysis of the ultrasonic signal amplitude when the character of the reflection surface has been changed from a planar case to a sharp corner case. The experiment was performed at a measurement distance within the interval from 100 mm to 215 mm. A nonlinear correlation between the amplitude of the ultrasound signal and the measured distance was demonstrated. By analyzing the frequency spectra, a poor nonlinear correlation between the maximum frequency component and the distance vector was found for the sharp corner case versus the planar case, which proved similar nonlinear characteristics as the signal amplitude marker. The strong linear correlation in the distance difference vectors in the amplitude analysis of the ultrasound signal confirmed the hypothesis of a direct relationship between the reflection surface geometric characteristic and the polarity of the difference. The ultrasound signal was identified as a 3rd-order dynamic system. The n... [more]
Multiple Graph Adaptive Regularized Semi-Supervised Nonnegative Matrix Factorization with Sparse Constraint for Data Representation
Kexin Zhang, Lingling Li, Jinhong Di, Yi Wang, Xuezhuan Zhao, Ji Zhang
February 21, 2023 (v1)
Keywords: image clustering, multiple graph, nonnegative matrix factorization, semi-supervised learning, sparse constraint
Multiple graph and semi-supervision techniques have been successfully introduced into the nonnegative matrix factorization (NMF) model for taking full advantage of the manifold structure and priori information of data to capture excellent low-dimensional data representation. However, the existing methods do not consider the sparse constraint, which can enhance the local learning ability and improve the performance in practical applications. To overcome this limitation, a novel NMF-based data representation method, namely, the multiple graph adaptive regularized semi-supervised nonnegative matrix factorization with sparse constraint (MSNMFSC) is developed in this paper for obtaining the sparse and discriminative data representation and increasing the quality of decomposition of NMF. Particularly, based on the standard NMF, the proposed MSNMFSC method combines the multiple graph adaptive regularization, the limited supervised information and the sparse constraint together to learn the mo... [more]
Energy Savings in the Heat Exchanger Network of an Oil Refinery Pre-Heat Train Unit Using a Path’s Combination at Different HRAT Values
Abdelbagi Osman, Mousab Salaheldeen Mirghani
February 21, 2023 (v1)
Keywords: energy savings, HEN retrofit, thermo-economic analysis, utility paths
Conservation of energy usage is essential in chemical process plants due to the expanded energy users and demands alongside the carry-on hike of energy prices. This study analyzed the performance of energy savings in a heat exchanger network (HEN). It is based on decreasing utility usage while increasing process-to-process heat exchange in HEN using a path combination approach at different heat recovery approach temperatures (HRATs). The approach generates different combined path options for heat shifting from utilities to exchangers in a HEN. In terms of cost targeting, the optimal HRAT in a HEN is determined for each path’s combination option. The study focused on the HEN of crude oil preheat trains. Shifting heat load between utilities implies adding and subtracting loads to and from exchangers in a HEN. Therefore, a minor retrofit to compensate for the heat transfer area is required for some HEN exchangers. The optimum HRAT corresponding to the lowest total cost was determined for... [more]
Pricing and Return Strategy Selection of Online Retailers Considering Consumer Purchasing Behavior
Xinggang Shu, Zhenhua Hu
February 21, 2023 (v1)
Subject: Other
Keywords: consumer purchase behavior, online retailer, return insurance, return strategy
This article mainly considers the coexistence of physical sales channels and online sales channels. Online retailers with online sales channels consider whether to provide return policies and whether to provide consumers with return insurance. The research established four return strategy models that: do not provide returns; provide returns but do not provide return insurance; provide return insurance, but the cost is borne by online retailers; and provide return insurance, but the cost is borne by consumers. The authors then studied the online retailers’ optimal return and shipping insurance selection strategies. The results show that when the proportion of residual return value after the value reduction of unit returned products was large, online retailers set higher sales prices and provided return policies, while offline retailers needed to reduce sales prices in order to attract more consumers. When the consumer unit product return compensation was relatively large, online retaile... [more]
Effect of Dynamic Biaxial Loading of Car Seats
Petr Lepsik, Vitezslav Fliegel, Ales Lufinka
February 21, 2023 (v1)
Subject: Other
Keywords: biaxial loading, car seat, measurement standards, testing, transfer characteristics
The aim of this article is to determine the effect of the biaxial loading of a car seat, in vertical and horizontal directions, on seating comfort. We measured the transfer characteristic in the vertical direction with a free load. The method of laboratory testing of the car seat was chosen due to the simple repetition of the tests, ensuring the same test conditions, with high accuracy of their reproduction. To determine the effect, tests with uniaxial loading were compared with tests with biaxial loading. The resulting characteristic was the transfer characteristic in the vertical direction. The effect of horizontal loading on the transfer characteristic of a car seat was determined.
Solubility of Biocompounds 2,5-Furandicarboxylic Acid and 5-Formylfuran-2-Carboxylic Acid in Binary Solvent Mixtures of Water and 1,4-Dioxane
Linli Xu, Jianhui Fu, Cunbin Du, Qianqian Xu, Baojian Liu, Zongbi Bao
February 21, 2023 (v1)
Subject: Biosystems
Keywords: 2,5-furandicarboxylic acid, 5-formylfuran-2-carboxylic acid, binary solvent mixtures, co-solvency phenomenon, solubility, water + 1,4-dioxane
The solubility of 2,5-furandicarboxylic acid (FDCA) and its synthetic intermediates (e.g., 5-formylfuran-2-carboxylic acid, FFCA) provides fundamental information for the preparation and purification of the value-added biocompound FDCA. We measured the solubility of FDCA and FFCA in binary water + 1,4-dioxane mixtures with different mixing ratios at 303.15 K−342.15 K. The obtained solubility values were correlated with the Jouyban-Acree-van’t Hoff model, and the preferential solvation theory was used to study the microscopic dissolution mechanism. The solubility of FDCA/FFCA increases with increasing temperature, and pure 1,4-dioxane dissolves more solutes than pure water. FFCA shows higher solubility than FDCA. In the binary solvent mixtures, the phenomenon of co-solvency exists for both FDCA and FFCA, i.e., at a 1,4-dioxane mole fraction of about 0.60, FDCA and FFCA dissolve the most. Acceptable mean percentage deviations (MPD) (5.5% and 6.9%) are obtained for FDCA and FFCA (Jouyban-... [more]
Mobile Robot Navigation Using Deep Reinforcement Learning
Min-Fan Ricky Lee, Sharfiden Hassen Yusuf
February 21, 2023 (v1)
Subject: Environment
Keywords: autonomous navigation, collision avoidance, mobile robots, reinforcement learning
Learning how to navigate autonomously in an unknown indoor environment without colliding with static and dynamic obstacles is important for mobile robots. The conventional mobile robot navigation system does not have the ability to learn autonomously. Unlike conventional approaches, this paper proposes an end-to-end approach that uses deep reinforcement learning for autonomous mobile robot navigation in an unknown environment. Two types of deep Q-learning agents, such as deep Q-network and double deep Q-network agents are proposed to enable the mobile robot to autonomously learn about collision avoidance and navigation capabilities in an unknown environment. For autonomous mobile robot navigation in an unknown environment, the process of detecting the target object is first carried out using a deep neural network model, and then the process of navigation to the target object is followed using the deep Q-network or double deep Q-network algorithm. The simulation results show that the mo... [more]
Generalized Mathematical Model of the Grain Drying Process
Ryszard Myhan, Marek Markowski
February 21, 2023 (v1)
Keywords: cereal grain, computer simulation, drying, mathematical model
Convective cereal grain drying is an energy-intensive process. Mathematical models are applied to analyze and optimize grain drying processes in different types of dryers and in different stages of drying to improve final grain quality and reduce energy consumption. The aim of the present study was to develop a generalized mathematical model of the grain drying process that accounts for all drying stages, including loading and unloading of unprocessed grain, drying, and cooling of dry grain. The developed mathematical model is a system of algebraic equations, where the calculated coefficients are determined by the thermophysical and diffusive properties of dried grain. The model was validated for batch drying of wheat, canola, and corn grain, as well as continuous flow drying of wheat grain. The results were compared with published findings. The relationships between energy consumption during drying and drying time vs. air temperature at the dryer inlet and air stream volume were deter... [more]
The Tobacco Leaf Redrying Process Parameter Optimization Based on IPSO Hybrid Adaptive Penalty Function
Danping Luo, Yingna Li, Shouguo Tang, Ailian Liu, Liping Zhang
February 21, 2023 (v1)
Keywords: adaptive penalty function, IPSO, RBF neural network, roaster exit moisture content and temperature
In the tobacco redrying process, process parameter settings are greatly influenced by ambient temperature and humidity, and the moisture content of the tobacco leaf. In the face of complex and variable tobacco leaf characteristics, it is difficult to accurately adapt the process parameters to fluctuations in the incoming material characteristics by manual experience alone. Therefore, an improved optimization method combining an improved particle swarm optimization algorithm (IPSO) and an adaptive penalty function is proposed, which can adaptively recommend the best combination of process parameters according to the dynamic incoming characteristics of the tobacco leaf, to reduce the deviation in the outlet moisture and temperature of the roaster under different processing standards of the tobacco leaf. Firstly, the Radial Basis Function (RBF) Neural Network is used to fit the relationship between process parameters and roaster exit moisture content and temperature. Then, taking the stan... [more]
Transport Behavior of Methane Confined in Nanoscale Porous Media: Impact of Pore Evolution Characteristics
Shan Wu, Sidong Fang, Liang Ji, Feng Wen, Zheng Sun, Shuhui Yan, Yaohui Li
February 21, 2023 (v1)
Keywords: coordination number, coupling, nanoconfined methane, pore network modeling, slip
As a key technical aspect contributing to shale gas development, nanoconfined methane flow behavior has received tremendous research interest, which remains challenging to understand clearly. The majority of previous contributions put emphasis on the mechanism model for methane confined in a single nanopore; at the same time, the other part focusing on an upscaling approach fails to capture the spatial pore-network characteristics as well as the way to assign pressure conditions to methane flow behavior. In light of the current knowledge gap, pore-network modeling is performed, in which a pore coordination number, indicating the maximum pores a specified pore can connect, gas flow regimes classified by Knudsen numbers, as well as different assigned pressure conditions, are incorporated. Notably, the pore-network modeling is completely self-coded, which is more flexible in adjusting the spatial features of a constructed pore network than a traditional one. In this paper, the nanoconfine... [more]
Assessing Waste Marble Powder Impact on Concrete Flexural Strength Using Gaussian Process, SVM, and ANFIS
Nitisha Sharma, Mohindra Singh Thakur, Raj Kumar, Mohammad Abdul Malik, Ahmad Aziz Alahmadi, Mamdooh Alwetaishi, Ali Nasser Alzaed
February 21, 2023 (v1)
Keywords: ANFIS, flexural strength, Gaussian processes, support vector machines, waste marble powder
The study’s goal is to assess the flexural strength of concrete that includes waste marble powder using machine learning methods, i.e., ANFIS, Support vector machines, and Gaussian processes approaches. Flexural strength has also been studied by using the most reliable approach of sensitivity analysis in order to determine the influential independent variable to predict the dependent variable. The entire dataset consists of 202 observations, of which 120 were experimental and 82 were readings from previous research projects. The dataset was then arbitrarily split into two subsets, referred to as the training dataset and the testing dataset, each of which contained a weighted percentage of the total observations (70−30). Output was concrete mix flexural strength, whereas inputs comprised cement, fine and coarse aggregates, water, waste marble powder, and curing days. Using statistical criteria, an evaluation of the efficacy of the approaches was carried out. In comparison to other algor... [more]
Developing Design Approaches for Tile Pattern Designs Inspired by Traditional Textile Patterns
Arus Kunkhet, Disaya Chudasri
February 21, 2023 (v1)
Keywords: cultural significance, design structure, frieze group, symmetry, textile pattern, tile pattern
This article presents multidisciplinary research that involved design (i.e., textiles, tiles, pattern design), mathematics (i.e., symmetry and seven frieze groups) and a viewpoint on product design and development for business opportunities. This research comprised a design experiment and a survey. In the design experiment, two design approaches were created to translate the characteristics of traditional textile patterns into new pattern designs for floor tiles. These two design approaches were entitled: “partial replication”, and “combination and simplification”. The seven frieze groups were used as a transformation rule in both design approaches, resulting in two sets of frieze patterns. Although they were derived from the same origin, they looked different. A survey was conducted with 61 respondents to gain outsiders’ perspectives on these new pattern designs. The findings include: (i) positive responses to applying traditional textile patterns to other products, (ii) plausible pro... [more]
Analysis of Laser Cutting Process for Different Diagonal Material Shapes
Jungsoo Choi, Ryoonhan Kim, Danbi Song, Dae-Won Cho, Jeong Suh, Seonmin Kim, Sang-Hyun Ahn
February 21, 2023 (v1)
Subject: Materials
Keywords: conductive heat transfer, diagonal shape, high-speed camera, laser cutting, laser processing, numerical simulation, Yb-YAG laser
In this study, the laser cutting characteristics were analyzed according to the shape of the back side of the specimen, and the laser cutting characteristics were compared according to the thickness of the edge (10 mm, 20 mm, and 30 mm). A Yb-YAG laser was used in this study, and the cutting target was STS304 with a thickness of 50 mm, and the cutting process was analyzed using a high-speed camera. In the experiment, it was found through image analysis that the cutting performance was excellent at 30 mm thickness of the edge. In order to analyze this reason, a thermal conduction analysis (numerical simulation) was performed, and it was confirmed that the thicker thickness of the edge caused a preheating effect during laser cutting due to a large amount of heat accumulation. This effect can be used as a reference for the initial processing state while cutting thick metals as it is a characteristic that has not been revealed before.
Regional Geological Disasters Emergency Management System Monitored by Big Data Platform
Xiaoping Qian
February 21, 2023 (v1)
Subject: Materials
Keywords: big data platform, disaster warning, emergency management system, geological disasters
In order to deal with the hazards caused by geological disasters in time, an emergency management system is proposed based on association rule data mining. With the support of a big data platform, a regional geological disaster emergency management system is built based on monitoring data. In the result analysis, the association rule algorithm demonstrates high computing power in the test, which can filter the data with strong association rules. In addition, the big data platform can allow data visualization, which has good data storage capacity and disaster early warning capacity. In the simulation test of the emergency management system, it was found that the system is feasible in theory. When it is applied to the actual disaster emergency management, it wasfound that, in the face of geological disasters, the processing speed of relevant departments increased by 59.4%, and the allocation of personnel and materials wasmore reasonable. The above results show that the big data platform... [more]
Interaction between Iron Fluoride and Molten FLiBe
Stepan P. Arkhipov, Yury P. Zaikov, Pavel A. Arkhipov, Albert R. Mullabaev
February 21, 2023 (v1)
Keywords: cathode polarization, equilibrium potential, fluoride melt, Gibbs energy, iron
The equilibrium potentials of iron in a LiF-BeF2-FeF2 melt were measured using the EMF method and were dependent upon the temperature and iron fluoride concentrations. The empirical equations for the isotherms and equilibrium polytherms of the iron fluoride concentration were obtained. The cathode polarization of iron fluoride in the molten mixture of lithium and beryllium fluoride was measured using the current switch off method from the stationary state. It was found that in the studied temperature and concentration ranges of iron fluoride in the LiF-BeF2 electrolyte, the valence state of iron in the melt is mainly +2. According to the experimental values of the equilibrium potentials of the iron electrode in the LiF-BeF2-FeF2 melt, the conditional standard potentials of iron were calculated relative to the fluoride reference electrode in the molten mixture of lithium and beryllium fluoride. The conditional standard values of the Gibbs energy change were calculated at the formation o... [more]
Analysis of Influencing Factors in Pilot Experiment for Synthesis of Natural Gas Hydrate by Spray Method
Yun Ma, Jinzhao Zhu, Qingguo Meng, Chunxiao Ding, Jinbing Teng, Xin Wang, Qian Lu
February 21, 2023 (v1)
Keywords: artificial synthesis, natural gas hydrate, pilot-scale experiment, spray method
In recent years, the technology of storing and transporting natural gas in the form of hydrate has received a lot of attention. At present, the research on the synthesis of natural gas hydrate for the purpose of storage and transportation is still in the laboratory stage, and its synthesis process is in the design and conception stage. The influencing factors of natural gas hydrate synthesis under pilot-scale conditions are more complex. Moreover, pilot experiments are oriented to actual production, and its economic feasibility and operational convenience have higher requirements. This paper aimed to study the influencing factors of gas hydrate synthesis by spray method under pilot-scale conditions. Under specific conditions of surfactant and pressure, we carried out research on the effects of reaction temperature, different forms of atomizers, high-pressure pump flow, experimental water, and other factors. Experiments show that the optimal synthesis conditions were a temperature of −5... [more]
Bt and G10evo-EPSPS Protein Expressed in ZDAB3 Corn Has No Impact on Nutritional Composition and Toxicological Safety
Xiaoxing Yu, Guo Chen, Ziying Zhou, Xiaoyun Chen, Xiaoyun He, Yue Jiao, Pengfei Wang
February 21, 2023 (v1)
Subject: Biosystems
Keywords: Cry1Ab, Cry2Ab, G10evo-EPSPS, nutritional composition, toxicology, transgenic maize
Genetically modified (GM) crops expressing insecticidal and herbicide-tolerant traits provide a new approach to agriculture production, but concerns about food safety were often raised by the public. The present research shows the findings of the nutritional assessment of ZDAB3 expressing insecticidal Cry proteins (Cry1Ab and Cry2Ab) and EPSPS protein (G10evo-EPSPS). The key nutrients and anti-nutrients of ZDAB3 maize were examined and contrasted with those of its non-transgenic control maize grown at the same locations during three planting seasons. The values for proximates, amino acids, fatty acids, minerals, vitamins, phytic acid, and trypsin inhibitor assessed for ZDAB3 were comparable to those of its non-transgenic control maize or within the range of values reported for other commercial lines. In addition, no adverse effects related to the G10evo-EPSPS protein in mammals were observed. These data indicated that the expression of Cry1Ab, Cry2Ab, and G10evo-EPSPS proteins in ZDAB3... [more]
Modeling Study on Melt Flow, Heat Transfer, and Inclusion Motion in the Funnel-shaped Molds for Two Thin-Slab Casters
Lin Xu, Qun-Wu Pei, Ze-Feng Han, Shuo Yang, Jian-Yu Wang, Yan-Tao Yao
February 21, 2023 (v1)
Keywords: CSP mold, electromagnetic braking, FTSR mold, heat transfer and solidification, inclusions movement, molten steel flow
For the purpose of studying compact strip production (CSP) funnel-shaped mold and flexible thin-slab rolling (FTSR) funnel-shaped mold, a three-dimensional (3D) multi-field coupling mathematical model was established to describe the electromagnetic braking (EMBr) continuous casting process. To investigate the metallurgical effect of EMBr in the CSP and FTSR funnel-shaped thin-slab molds, a Reynolds-averaged Navier−Stokes (RANS) turbulence model, together with an enthalpy−porosity approach, was established to numerically simulate the effect of ruler EMBr on the behaviors of melt flow, heat transfer, solidification, and inclusion movement in high-speed casting. The simulation results indicate that the application of ruler EMBr in the CSP and FTSR molds shows great potential to improve the surface temperature of molten steel and reduce the penetration depth of downward backflow. This contributes to the melting of the slag rim near the meniscus region and facilitates the floating removal o... [more]
Electrospinning Composites as Carriers of Natural Pigment: Screening of Polymeric Blends
Sergiana dos Passos Ramos, Letícia Guerreiro da Trindade, Tatiana Martelli Mazzo, Elson Longo, Fabiana Perrechil Bonsanto, Veridiana Vera de Rosso, Anna Rafaela Cavalcante Braga
February 21, 2023 (v1)
Subject: Materials
Keywords: anthocyanins, C-phycocyanin, carotenoids, composites, electrospun, PEO, rheological properties, Spirulina, zein
Several studies have already demonstrated that electrospinning is an excellent tool for forming nano/microfibers. However, the number of parameters affecting the formation of the structures has become a great challenge, including the polymeric solutions’ rheological properties, directly affecting the morphology of the fibers formed. The present work aimed to produce polymeric composites and determine their rheological properties, comparing them to the morphology of the fibers formed by electrospinning. Also, to evaluate their potential use as the carriers of natural pigments. To this end, a distinct combination of solutions containing Chitosan/Gelatin, Chitosan/poly(ethylene) oxide (PEO) and Zein/PEO was produced and submitted to electrospinning. The sample containing zein manufactured the structures smaller in diameter (201.3 ± 58.6 nm) among those studied. Besides, it was observed that adding PEO to the solutions impacts the increase in viscosity and shear thinning behavior, guarante... [more]
Production of Ultra-Clean Coal by the Combined Method of Grinding and Collector Gasification Flotation
Liang Shen, Jiabao Gong, Yifang Liu
February 21, 2023 (v1)
Keywords: collector gasification, flotation, grinding, ultra-clean coal
The preparation and application of ultra-clean coal is one of the important aspects of clean energy technology. However, the preparation of ultra-clean coal is mainly chemical methods, which are low in efficiency, high in energy consumption and expensive. It is urgent to find an effective method to prepare ultra-clean coal. In this paper, the combined method of grinding and the collector gasification flotation method was used to obtain ultra-clean coal. The effects of grinding time on the particle size composition, mineral dissociation, surface properties and flotation results of coal samples were studied. The grinding test results show that with the increase in grinding time, the particle size and the pore diameter of coal samples decreased gradually, while the specific surface area and pore volume of coal samples gradually increased. When the grinding time was 20 min, the D90 and D[4,3] of grinding products were 5.20 um and 4.23 um, respectively. The ash content of −1.3 g/cm3 was les... [more]
Experimental Study and an RSM Modelling on Drilling Characteristics of the Sheep Horn Particle Reinforced Epoxy Composites for Structural Applications
Chandrashekar Anjinappa, Manjunath Y. J, Omar Shabbir Ahmed, Mohamed Abbas, Ahmad Aziz Alahmadi, Mamdooh Alwetaishi, Ali Nasser Alzaed
February 21, 2023 (v1)
Keywords: drilling, flexural test, sheep horn particle, Taguchi analysis, tensile test, thrust force measurement
Recent environmental concern has been raised about the development of biocomposites because of their low cost, eco-friendliness, and biodegradability. Machining of polymeric composite is inevitable during assembly of structural components. In view of creating holes in structural composites, drilling is necessary and it is essential to carry out research to find the optimal machining parameters. The experimental assessment and prediction of the thrust force and torque involved in drilling composites reinforced with sheep horn are presented in this work. The matrix and sheep horn particles were combined in the right proportions before being moulded and poured into a mould, then allowed to cure at room temperature. Investigated properties included ultimate tensile strength, flexural strength, and hardness. To evaluate the quality of the hole, micrographs of the drilled hole were employed. When the mixture was optimised based on the properties, it was found that a 70:30 ratio produced the... [more]
Processes in Doping System: Quantification Reports in Mixed Martial Arts Fighters
Shyla Del-Aguila-Arcentales, Aldo Alvarez-Risco, Mercedes Rojas-Osorio, Hugo Meza-Perez, Gloria Rojas-Cangahuala, John Simbaqueba-Uribe, Niria Goñi Avila, Rosa Talavera-Aguirre, Luis Mayo-Alvarez, Jaime A. Yáñez
February 21, 2023 (v1)
Keywords: contamination, doping, mix martial arts, MMA, sanction, sports, violation
Mixed martial arts (MMA) has always been surrounded by controversy due to the unusual muscle development of its participants, so it is crucial to know the strategies that have been implemented to reduce doping cases. The main purpose of this paper is to describe the various cases of doping detected by USADA in UFC MMA participants. In addition, strategies that are being developed to reduce cases of positive doping are proposed. From the UFC USADA database, doping cases were extracted, obtaining the substance or substances involved; the formula, physiological effect and the athletes involved; the dates of the sampling; if it was out of competition or in-competition and the sanction time. The substances that were most involved were found to be Ostarine (22), Clomiphene (9), Diuretics (10) and Stanozolol (9). Some sanctions were diminished because they were treated with contamination of supplements (cases of Ostarine) and cases of contamination of meat (Clomiphene). When contaminated supp... [more]
Showing records 37668 to 37692 of 43292. [First] Page: 1 1504 1505 1506 1507 1508 1509 1510 1511 1512 Last
(0.82 seconds)
[Show List of Record Types]

[0.83 s]