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Showing records 2462 to 2486 of 43292. [First] Page: 1 96 97 98 99 100 101 102 103 104 Last
The Enhanced Oil Recovery Effect of Nitrogen-Assisted Gravity Drainage in Karst Reservoirs with Different Genesis: A Case Study of the Tahe Oilfield
Hong Cheng
September 20, 2023 (v1)
Keywords: carbonate reservoir, enhanced oil recovery, fracture vuggy, karst reservoirs with different genesis, nitrogen-assisted gravity drainage
For the Tahe Oilfield, there are multiple sets of karst reservoirs with different genesis developed in carbonate fracture-vuggy reservoirs and the varying karst reservoir type has a considerable influence on the distribution of residual oil. The complex characteristics of different karst reservoirs and the difficulty in producing the remaining oil in the middle and lower part of the reservoir greatly restrict the recovery effects. This work managed to comprehensively investigate the action mechanism of nitrogen-assisted gravity drainage (NAGD) on remaining oil in reservoirs with different karst genesis through modeling and experiments. Based on geological characteristics and modeling results, a reservoir-profile model considering reservoir type, fracture distribution, and the fracture−cave combination was established, the displacement experiments of main reservoirs such as the epikarst zone, underground river, and fault karst were carried out, and the oil−gas−water multiphase flow was... [more]
Design and Implementation of a Three-Dimensional CAD Graphics Support Platform for Pumps Based on Open CASCADE
Houlin Liu, Zhicai Wu, Shuolei Yuan, Yong Wang, Liang Dong
September 20, 2023 (v1)
Keywords: centrifugal pump parameterized modeling, geometric kernel, rendering engine, three-dimensional computer-aided design, three-dimensional visualization
In the pump industry, designers commonly utilize mainstream three-dimensional computer-aided design (CAD) software (Unigraphics NX 12.0 and SolidWorks 2023). However, these CAD packages are generic and not optimized for the specific requirements of the pump industry. This leads to a lack of flexibility and increased complexity in their usage, as well as higher computational demands, resulting in elevated learning and operational costs. Additionally, there are concerns about potential information leaks and software restrictions. In this paper, we studied the organization architecture of commercial three-dimensional CAD software, and compared and analyzed the geometric kernels and rendering engines of mainstream three-dimensional software. Using the Open CASCADE geometric kernel and OpenSceneGraph rendering engine, together with the Visual Studio 2021 development environment and Qt interface library, we developed an autonomous copyright three-dimensional CAD graphics support platform for... [more]
Pore Structure Change in the Continental Shale Oil Reservoir and Its Main Influencing Factors: A Case Study of the Chang 7 Member in the Ordos Basin
Xin He, Shijia Chen, Cong Hu, Haifeng Zhang, Feisheng Mou, Linfeng Dai, Yifan Lu, Xiaoyan Fu, Meimei Han
September 20, 2023 (v1)
Subject: Materials
Keywords: Chang 7 member, influencing factors, oil content, Ordos Basin, reservoir, shale oil
Shale oil in the Chang 7 member is the main target for further exploration in the Ordos Basin. However, the lack of research on the characteristics of the Chang 7 member’s mudstone and shale reservoir has seriously affected the next stage of exploration for shale oil in the Chang 7 member. This study analyzed in detail the changes in the pore structure of different types of reservoirs and their influencing factors in detail through experiments such as gas adsorption, nuclear magnetic resonance, and high-pressure mercury intrusion. The results showed that black shale is mainly composed of micropores, with a micropore ratio of up to 79.88%. Dark mudstone and silty mudstone are mainly composed of mesopores, with a mesopore ratio greater than 30%. Argillaceous sandstone is mainly composed of large pores, accounting for 78.57%. From black shale to muddy sandstone, the proportion of micropores decreases, while the proportion of macropores increases. The micropore volume is mainly controlled... [more]
High Dimensional Model Representation Approach for Prediction and Optimization of the Supercritical Water Gasification System Coupled with Photothermal Energy Storage
Haoxing Li, Jianhong Lei, Ming Jia, Hongpeng Xu, Shaohua Wu
September 20, 2023 (v1)
Keywords: high dimensional model representation (HDMR), multi-objective optimization, photothermal energy storage, supercritical water gasification
Supercritical water gasification (SCWG) coupled with solar energy systems is a new biomass gasification technology developed in recent decades. However, conventional solar-powered biomass gasification technology has intermittent operation issues and involves multi-variable characteristics, strong coupling, and nonlinearity. To solve the above problems, firstly, a solar-driven biomass supercritical water gasification technology combined with a molten salt energy storage system is proposed in this paper. This system effectively overcomes the intermittent problem of solar energy and provides a new method for the carbon-neutral process of hydrogen production. Secondly, the high dimensional model representation (HDMR) approach, as a surrogate model, was used to predict the production and lower heating value of syngas developed in Aspen Plus, which were validated using experimental data obtained from the literature. The ultimate analysis of biomass, temperature, pressure, and biomass-to-wate... [more]
Techno-Economic Considerations on Nanocellulose’s Future Progress: A Short Review
Giannis Penloglou, Aikaterini Basna, Alexandros Pavlou, Costas Kiparissides
September 20, 2023 (v1)
Keywords: bacterial nanocellulose (BNC), lignocellulosic biomass, nanocellulose, nanocrystalline cellulose (NCC), nanofibrillated cellulose (NFC), production cost, Technoeconomic Analysis
Nanocellulose (NC) is an emerging natural material that offers great potential for various applications due to its unique properties and renewable character. Nowadays, as NC production technologies are advancing, it is essential to evaluate their economic feasibility, technological maturity and commercialization potential using systematic techno-economic analysis (TEA). The present study considers both technical and economic aspects of NC production and analyzes them in two ways: first, by developing a new concept based on the production of different types of NC through the conversion of lignocellulosic biomass by chemical and mechanical technologies, and second, by a comparative review of existing TEA studies in the open literature. Three specific scenarios and two case studies are evaluated by comparing specific key performance indicators (KPIs), such as the production cost (PC) and minimum product selling price (MPSP) of NC. As a result, a short though comprehensive overview of the... [more]
Study on Mechanism of MSWI Fly Ash Solidified by Multiple Solid Waste-Based Cementitious Material Using the Rietveld Method
Xiaoli Wang, Pingfeng Fu, Wei Deng, JinJin Shi, Miao Xu
September 20, 2023 (v1)
Subject: Materials
Keywords: cementitious material, heavy metals, MSWI fly ash, multiple solid waste, Rietveld method, solidification, X-ray diffraction
A novel multiple solid waste-based cementitious material (MSWCM) was developed to immobilize municipal solid waste incineration (MSWI) fly ash. The compressive strength of MSWCM with different ratios of MSWI fly ash reached the standard requirements after curing for 28 days. X-ray powder diffraction (XRD) in combination with the Rietveld method was employed to investigate the content and phase transformation of hydration products. The main hydration products of pure MSWCM paste were C-S-H, hydroxyapatite, ettringite and C-A-S-H. With increases in curing time, the content of ettringite and C-A-S-H increased significantly. The main hydration products of MSWCM paste with MSWI fly ash were C-S-H and Friedel’s salt. The contents increased markedly with increased curing time from 21.8% to 28.0% and from 8.53% to 16.7%, respectively. Additionally, a small amount of PbHPO4 (0.51−0.96%) and lead phosphate Pb3(PO4)2 (0.14−0.51%) were detected, indicating that phosphate had an effective curing ef... [more]
Soy Protein Nanofibers Obtained by Solution Blow Spinning
Agata Penconek, Dorota Kasak, Arkadiusz Moskal
September 20, 2023 (v1)
Subject: Biosystems
Keywords: nanofibers, polyethylene oxide, solution blow spinning, soy protein isolate
The climate crisis, growing pollution of the environment with waste, and ubiquitous microplastics have encouraged the search for new methods and new opportunities to use natural materials in the least harmful processes. Replacing synthetic materials with raw materials is not only a matter of “fashion”, but also a necessity. Therefore, this study aimed to produce fibers from an aqueous solution containing the highest possible concentration of soy protein isolate (SPI) through solution-blowing. As the aqueous solution of SPI has no fiber-forming potential, polyethylene oxide (PEO) was used as the carrier/matrix. The rheology of the aqueous PEO solution and PEO/SPI blends (flow curves, loss modulus, and storage modulus) was then analyzed. The proportions of the PEO/SPI mixtures and the process parameters were determined on this basis. As a result of the conducted research, nanofibers were produced from water solutions of PEO/SPI with a soy protein content of up to 7.88%, with a PEO share... [more]
An Early Study on the Synthesis of Lignin-Graft-(Net-Poly(acrylamide-co-N,N′methylenebisacrylamide)), Characterization of the Produced Copolymer, and Evaluation of Its Performance as Adsorbent for Lead Removal from Wastewater Purposes
María Fernanda Munguía-Quintero, Miguel Ángel Vega-Hernández, Alberto Rosas-Aburto, Martín Guillermo Hernández-Luna, Simón López-Ramírez, José Fernando Barragán-Aroche, Eduardo Vivaldo-Lima
September 20, 2023 (v1)
Subject: Materials
Keywords: adsorbents, lead adsorption, polymer grafting, polymer modification
A lignin-graft-(net-poly(acrylamide-co-N,N′methylenebisacrylamide)) copolymer was synthesized by conventional free-radical crosslinking copolymerization using conventional and microwave heating. Grafting of the polymer network onto lignin was confirmed by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), and elemental analysis. The performance of the modified materials for the removal of lead from water was evaluated. The materials obtained by the two types of heating showed excellent removal efficiencies: sample HLigAM4h, 96%; and sample HLigAMMW5, 86%. The maximum adsorption capacity of HLigAM4h was 209.82 mg g−1. The obtained copolymer (sample HLigAM4h) was characterized by X-ray photoelectron spectroscopy (XPS) and SEM/EDS after its evaluation as an adsorbent, which confirm the adsorption of Pb2+. This is the first of a series of st... [more]
Pressurized Liquid Extraction (PLE) in an Intermittent Process as an Alternative for Obtaining Passion Fruit (Passiflora edulis) Leaf Hydroalcoholic Extract (Tincture)
Larissa da Cunha Rodrigues, Renata Barbosa Bodini, Fernando de Lima Caneppele, Gustavo César Dacanal, Eduardo José Crevelin, Luiz Alberto Beraldo de Moraes, Alessandra Lopes de Oliveira
September 20, 2023 (v1)
Keywords: Extraction, Fick’s Law, high-pressure, intermittent process, isovitexin, phenolic compounds
Tinctures are medicinal plant extracts obtained by extraction with a hydroalcoholic solution (70%) by percolation (PER). This process takes about 26 h to prepare, in addition to using a large amount of solvent. In our research, passion fruit leaf tinctures were obtained using extract with the same pressurized hydroalcoholic solution as in an intermittent process. The objective was to demonstrate that this emerging technology can be economical and profitable. An optimization using Central Composite Rotatable Design (CCRD) was performed to evaluate the influence of process variables on the yields and compositions of the extracts. The temperature (T) was the factor that most influenced the responses. Extraction with pressurized liquid (PLE) provided total yields and total phenolic and flavonoid contents in greater amounts than PER. The optimized conditions of the process variables studied in the CCRD for the highest content of total phenolics (43.2 mg GAE/g) and flavonoids (58.8 mg QE/g)... [more]
Plasma-Arc-Flow Technology for Sustainable Treatment of High-Impact Fluid Waste: A Graphene-Based Material for Industrial-Wastewater Purification
Carmine Mongiello, Mohammad Ghoreishi, Vinod Kumar Sharma, Liberato Verdoliva, Sabato Aprea, Paolo Venturini, Gianluca Pesce
September 20, 2023 (v1)
Subject: Materials
Keywords: Energy Efficiency, graphene, Optimization, plasma arc flow, wastewater treatment
The research presented aimed to address the treatment of fluid waste with significant environmental impact by utilizing plasma technology, specifically plasma arc flow (PAF). The goal was to develop a novel purification material based on graphene for industrial applications and to optimize the treatment process. Analysis and monitoring of a submerged arc plasma reactor were the main goals of this research. This entailed a careful examination of the incoming wastewater that needed to be treated with the goal of identifying its precise composition characteristics with the relative tolerances needed for the reactions that were to follow in the reactor. The focus of the analysis was on input-parameter optimization, production of characteristic curves, and analysis of the factors affecting hydrogen evolution in syngas. Additionally, the study investigated how to determine the best viscosity for a particular input matrix by carrying out an evaluation study. The effects of this parameter were... [more]
Pyridazinic Bioisosteres with Potential Applications in Medicinal Chemistry and Agriculture
Roxana Angela Tucaliuc, Violeta Mangalagiu, Ionel I. Mangalagiu
September 20, 2023 (v1)
Subject: Biosystems
Keywords: antibacterial and antifungal activity, classical and nonclassical bioisosteres, height and weight of plantlets, microwave, pyridazine compounds, seedling growth, spectral characterisation, stereochemistry, synthesis, wheat germination
Bioisosteres are substituents or groups (atoms, ions, or molecules) with similar chemical or physical properties, and which usually have similar biological properties. Pyridazine and its derivatives are invaluable scaffolds in medicinal chemistry, having a large variety of activities such as antibacterial, antifungal, antimalarial, anticancer, antituberculosis, antihypertensive, etc. Also, the pyridazine core is of high interest in agriculture, being used as a growth factor for plants, herbicides, etc. This study aims to review our previous contributions related to antimicrobials and the germination and seedling capabilities of some seeds and plants of some pyridazine classical and nonclassical bioisosteres. So, we present herein the synthesis (under conventional thermal heating and microwave irradiation) and spectral characterization of seven series of pyridazine bioisosteres, the in vitro antimicrobial activity (against different strains of Gram-positive and Gram-negative bacteria an... [more]
Deformation Characteristics of Asymmetric Gradient Extrusion in Preparing Ultra-Fine-Grained Bulk Materials
Junkai Fan, Jikang Li, Wei Liu, Chengpeng Wang
September 20, 2023 (v1)
Subject: Materials
Keywords: asymmetric gradient extrusion, deformation characteristics, finite element analysis, slip line field, ultra-fine-grained bulk materials
In this paper, a novel method for the preparation of ultra-fine-grained bulk materials called asymmetric gradient extrusion (AGE) is proposed. In AGE, the cross-section of the extrusion channel is a rectangle, and two inclined planes are staggered along the extrusion direction. To realize repetitive extrusion, the thickness of the workpiece is limited to be equal to the width of the channel outlet. In order to study the mechanism of ultra-fine grain formation in AGE, the deformation characteristics of AGE were investigated. First, the slip line field method was used to theoretically analyze the deformation characteristics and grain splitting in AGE. Then, the plastic deformation behavior of bulk samples in AGE and traditional extrusion was investigated and compared with the finite element method. In addition, the deformation characteristic and microstructure variation of pure copper bulk samples in AGE were experimentally investigated. The results showed that the deformation characteri... [more]
Three-Dimensional Analysis of the Flow Characteristics Induced by a Cubic Artificial Reef with Diversions
Haiying Mao, Ziyi Wang, Cong Hu, Kairui Wang
September 20, 2023 (v1)
Keywords: cubic artificial reef with diversion, cut-opening ratio, flow characteristics, flow velocity, three-dimensional analysis
In this paper, the flow characteristics induced by a cubic artificial reef with diversions (DCAR) were investigated using computational fluid dynamics (CFD). The results showed that the design of a DCAR can greatly improve the flow field range compared to typical cubic artificial reefs. The upwelling volume of the DCAR was more than 16 times that of a typical cubic artificial reef. The flow field effect produced the best results when the cut-opening ratio (COR) was 0.1−0.2 with constant flow. The parameters of the upwelling and back vortex increased with an increase in the flow velocity, and it decreased with an increase in the COR. The drag coefficient was less affected by the flow velocity, which remained between 1.32 and 1.44. The new type of artificial reef can improve the flow characteristics around the reefs.
Effect of Atmospheric Cold Plasma on the Aroma of Pineapple Juice: Improving Fresh and Fruity Notes and Reducing Undesired Pungent and Sulfurous Aromas
Elaine C. M. Porto, Edy S. de Brito, Sueli Rodrigues, Fabiano A. N. Fernandes
September 20, 2023 (v1)
Keywords: Ananas comosus, aroma, dielectric barrier discharge plasma, food chemistry, quality
Pineapple aroma is characterized by several esters, which confers its fresh and fruity aroma. However, high concentrations of methyl hexanoate and thioesters bring an undesired pungently sweet aroma and sulfurous notes to pineapple juice. This study investigates the chemical effects of cold plasma on the aroma compounds and descriptors of pineapple juice, evaluating the effects of plasma on its esters and thioesters. Dielectric barrier discharge plasma was applied to pineapple juice, varying the excitation frequency (50 to 1000 Hz) and processing time (10 to 20 min) at constant voltage (20 kV). Plasma treatment induced successive demethylation of esters and the conversion of methyl esters into ethyl esters. Thioesters showed to be more stable under plasma treatment. Proper setting of plasma operating conditions enabled an improvement in the fresh and fruity descriptors of pineapple juice, a reduction of its undesired pungently sweet aroma, but an increase in the influence of sulfurous... [more]
Sedimentary Genesis and Model Analysis of Shale Lithofacies in Jiyang Depression
Cunfei Ma, Shuangpeng Liu, Qi Zhao, Yongjun Fan, Yaoyao Qian, Xiantai Liu, Xinmin Ge
September 20, 2023 (v1)
Subject: Other
Keywords: Jiyang depression, lithofacies types, paleogene, sedimentary genesis, sedimentary model, shale
Based on core observation, rock thin sections, logging data, and testing data, taking the shale of the upper submember of the 4th Member to the lower submember of the 3rd Member of Paleogene Shahejie Formation in Jiyang Depression of Bohai Bay Basin as an example, we determine the lithofacies division scheme, divide the main lithofacies types, analyze the sedimentary origin and development location of different shale lithofacies, establish the continental lake basin sedimentary model, determine the types and enrichment areas of favorable lithofacies, and provide guidance for the exploration and development of Shale oil. The results show that: (1) According to the mineral composition, sedimentary structure, and organic matter abundance, the division scheme of shale lithofacies in the study area is proposed, and the shale lithofacies of the study area was mainly divided into 17 types. (2) Based on the lithologic changes, the lacustrine sedimentary shale area was divided into muddy water... [more]
Prediction of Marine Thin Shale Gas Reservoir with Seismic Phase-Controlled Nonlinear Stochastic Inversion
Qingming Xie, Yanming Wu, Qian Huang, Yunbing Hu, Xiaoliang Hu, Xiaozai Guo, Dongming Jia, Bin Wu
September 20, 2023 (v1)
Keywords: nonlinear stochastic inversion, reservoir prediction, seismic facies, shale gas, thin layer
Due to the complicated interference sources and low signal-to-noise ratio of seismic records, conventional seismic inversion methods are difficult to accurately identify shale gas reservoirs with a thickness of less than 10 m. This presents great challenges to shale gas exploration and development in China. Seismic phase-controlled nonlinear stochastic inversion (SPCNSI) is related to the heterogeneity of underground media. With the constraints of the stratigraphic sequence or seismic facies models, the minimum value between the seismic model and seismic record can be solved through iterative processes. Based on the solved acoustic velocity in formation, the constraints for SPCNSI can be formed with the matching relationship between target layers and different sequences in three-dimensional space. The prediction resolution of an unconventional reservoir can be effectively improved by combining logging, geological and seismic information. The method is suitable for predicting thin shale... [more]
Breaking New Ground: Exploring the Promising Role of Solid-State Fermentation in Harnessing Natural Biostimulants for Sustainable Agriculture
Roberto Carlos Solano Porras, Adriana Artola, Raquel Barrena, Golafarin Ghoreishi, Cindy Ballardo Matos, Antoni Sánchez
September 20, 2023 (v1)
Keywords: crop improvement, natural biostimulant, organic waste, solid-state fermentation, sustainable agriculture
Agriculture has been experiencing a difficult situation because of limiting factors in its production processes. Natural biostimulants (NBs) have emerged as a novel alternative. This study reviews NBs produced through solid-state fermentation (SSF) from organic waste, focusing on processes and production methods. The aim is to highlight their potential for improving agricultural productivity and promoting sustainable agriculture. Through a literature review, the effects of NBs on crops were summarized, along with the challenges associated with their production and application. The importance of standardizing production processes, optimizing fermentation conditions, and assessing their effects on different crops is emphasized. Furthermore, future research areas are introduced, such as enhancing production efficiency and evaluating the effectiveness of SSF-produced NBs in different agricultural systems. In conclusion, SSF-produced NBs offer a promising alternative for sustainable agricul... [more]
A Cloud-Edge Computing Method for Integrated Electricity-Gas System Dispatch
Xueping Li, Ziyang Wang
September 20, 2023 (v1)
Subject: Energy Policy
Keywords: cloud-edge computing, integrated electric–gas system, MADDPG, optimal dispatch
An integrated electric−gas system (IEGS) is the manifestation and development direction of a modern smart power system. This paper employs the cloud-edge computing method to research IEGS’s optimal dispatch to satisfy data protection requirements between power systems and natural gas systems and reduce data transmission pressure. Based on cloud-edge computing architecture, this paper constructs a cloud-edge computing method based on the Multi-agent Deep Deterministic Policy Gradient (MADDPG) algorithm to solve optimal dispatch problems. Then, this paper proposes an IEGS dispatch strategy based on cloud-edge computing, which conducts distributed computing independently at the edge of power and natural gas, and the cloud implements global dispatch based on boundary information and edge learning parameters. This method does not require the exchange of all information between the power system and natural gas system, effectively protecting data privacy. This paper takes the improved IEGS of... [more]
Evaluation and Prediction of the Effect of Fabric Wetting on Coolness
Zijiang Wu, Yunlong Shi, Xiaoming Qian, Haiyang Lei
September 20, 2023 (v1)
Keywords: coolness sensation, random forest regression model, sensory evaluation, thermal absorptivity, wet state
As an important parameter of garment comfort, the thermal sensation of fabrics changes with factors such as sweat-induced humidity, making it a crucial area of research. To explore the coolness sensation of fabrics under different humidities, we tested heat transfer between fabrics and skin for 20 different fabrics with varying thermal absorption rates using fuzzy comprehensive evaluation to objectively assess their coolness levels. Subjective evaluation was then obtained by having subjects touch the fabrics and provide feedback, resulting in a subjective evaluation of their coolness levels. We compared the objective and subjective evaluations and found them to be highly consistent (R2 = 0.909), indicating accurate objective classification of fabric coolness levels. Currently, random forest regression models are widely used in the textile industry for classification, identification, and performance predictions. These models enable the prediction of fabric coolness levels by simultaneou... [more]
Formation Characterization and Type Prediction Based on Geophysical Well Log Data in Horizontal Well: A Case Study of Triassic Chang 8 Formation in Shunning Region, Central Ordos Basin
Jiaqi Li, Liang Xiao, Hui Xi, Ruiqiang Chi, Hucheng Wen, Wenjing Zhang
September 20, 2023 (v1)
Subject: Materials
Keywords: anisotropy analysis, formation classification, formation physical properties, pore structure
The role of the horizontal well in developing unconventional oil and gas reservoirs is particularly significant. Different from vertical wells, horizontal wells are greatly affected by many factors, e.g., well track, surrounding mudstone, resistivity, and pore structure heterogeneity in horizontal and vertical directions. These make it difficult to evaluate reservoir parameters and determine optimized test layers. In order to improve formation evaluation in horizontal wells, it is necessary to carry out the research of analyzing formation anisotropy, predict physical property parameters, and classify formation to determine high-quality intervals. In this study, taking Triassic Chang 8 Formation in Shunning Region, Central Ordos Basin as an example, 40 core samples were drilled and applied for nuclear magnetic resonance (NMR), mercury injection capillary pressure (MICP), and resistivity experiments. The porosity, permeability, resistivity, and pore structure anisotropy are analyzed. Res... [more]
A New Approach to the Preparation of Stable Oxide-Composite Cobalt−Samarium Catalysts for the Production of Hydrogen by Dry Reforming of Methane
A. G. Dedov, A. S. Loktev, V. A. Arkhipova, M. A. Bykov, A. A. Sadovnikov, K. A. Cherednichenko, G. A. Shandryuk
September 20, 2023 (v1)
Keywords: cobalt–samarium oxide catalysts, dry reforming of methane, heterogeneous catalysis, Hydrogen, Syngas
A new approach to preparing a series of Co/Sm2O3 catalysts for hydrogen production by the dry reforming of methane has been developed. The catalyst precursors were synthesized with a simple method, including the evaporation of aqueous solutions of cobalt and samarium nitrates, followed by a short-term calcination of the resulting material. The as-prepared and spent catalysts were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, temperature-programmed reduction, and thermogravimetric analysis. The content of cobalt in the synthesized materials affects their phase composition and carbonization resistance in the dry reforming of the methane reaction. It has been shown that preheating in N2 atmosphere produces catalysts that provide a stable yield of hydrogen and CO of 94−98% for at least 50 h at 900 °C. These yields are among the highest currently available for the dry reforming of methane catalysts made from Co-Sm complex oxides. It h... [more]
Cadmium Elimination via Magnetic Biochar Derived from Cow Manure: Parameter Optimization and Mechanism Insights
Yi Wen, Dingxiang Chen, Yong Zhang, Huabin Wang, Rui Xu
September 20, 2023 (v1)
Keywords: artificial neural network, cadmium removal, cow manure, magnetic biochar, response surface methodology
Designing an efficient and recyclable adsorbent for cadmium pollution control is an urgent necessity. In this paper, cow manure, an abundant agricultural/animal husbandry byproduct, was employed as the raw material for the synthesis of magnetic cow manure biochar. The optimal preparation conditions were found using the response surface methodology model: 160 °C for the hydrothermal temperature, 600 °C for the pyrolysis temperature, and Fe-loading with 10 wt%. The optimal reaction conditions were also identified via the response surface methodology model: a dosage of 1 g·L−1, a pH of 7, and an initial concentration of 100 mg·L−1. The pseudo-second-order model and the Langmuir model were used to fit the Cd(II) adsorption, and the adsorption capacity was 612.43 mg·g−1. The adsorption was dominated by chemisorption with the mechanisms of ion-exchange, electrostatic attraction, pore-filling, co-precipitation, and the formation of complexations. Compared to the response surface methodology m... [more]
CuFe2O4 Magnetic Nanoparticles as Heterogeneous Catalysts for Synthesis of Dihydropyrimidinones as Inhibitors of SARS-CoV-2 Surface Proteins—Insights from Molecular Docking Studies
Sónia A. C. Carabineiro, Gullapalli B. Dharma Rao, Lakhwinder Singh, Bendi Anjaneyulu, Mozhgan Afshari
September 20, 2023 (v1)
Subject: Biosystems
Keywords: Biginelli reaction, copper ferrite, COVID-19, dihydropyrimidinones, heterocycles, heterogeneous catalyst, hydroxychloroquine, molecular docking, multicomponent reaction, nanoparticles
In this study, we present the highly efficient and rapid synthesis of substituted dihydropyrimidinone derivatives through an ultrasound-accelerated approach. We utilize copper ferrite (CuFe2O4) magnetic nanoparticles as heterogeneous catalysts, employing the well-known Biginelli reaction, under solvent-free conditions. The impact of the solvent, catalyst amount, and catalyst type on the reaction performance is thoroughly investigated. Our method offers several notable advantages, including facile catalyst separation, catalyst reusability for up to three cycles with the minimal loss of activity, a straightforward procedure, mild reaction conditions, and impressive yields, ranging from 79% to 95%, within short reaction times of 20 to 40 min. Furthermore, in the context of fighting COVID-19, we explore the potential of substituted dihydropyrimidinone derivatives as inhibitors of three crucial SARS-CoV-2 proteins. These proteins, glycoproteins, and proteases play pivotal roles in the entry... [more]
An Interpretable Predictive Model for Health Aspects of Solvents via Rough Set Theory
Wey Ying Hoo, Jecksin Ooi, Nishanth Gopalakrishnan Chemmangattuvalappil, Jia Wen Chong, Chun Hsion Lim, Mario Richard Eden
September 20, 2023 (v1)
Keywords: health indices, Machine Learning, organic solvents, rough set theory, rough set-based machine learning
This paper presents a machine learning (ML) approach to predict the potential health issues of solvents by uncovering the hidden relationship between substances and toxicity. Solvent selection is a crucial step in industrial processes. However, prolonged exposure to solvents has been found to pose significant risks to human health. To mitigate these hazards, it is crucial to develop a predictive model for health performance by identifying the contributing factors to solvent toxicity. This research aims to develop a predictive model for health issues related to solvent toxicity. Among various algorithms in ML, Rough Set Machine Learning (RSML) was chosen for this work due to its interpretable nature of the generated models. The models have been developed through data collection on the toxicity of various organic solvents, the construction of predictive models with decision rules, and model verification. The results reveal correlations between solvent toxicity and the Balaban index, vale... [more]
Physical and Chemical Phenomena during the Production of Hydrogen in the Microwave Discharge Generated in Liquid Hydrocarbons with the Barbotage of Various Gases
Timur S. Batukaev, Igor V. Bilera, Galina V. Krashevskaya, Yuri A. Lebedev
September 20, 2023 (v1)
Subject: Materials
Keywords: discharge in liquids, gas chromatography, hydrogen production, microwave discharge, optical emission spectroscopy, shadow photographs
The physical and chemical characteristics of the microwave discharge in petroleum solvent during hydrogen production processes involving Ar, He, and CO2 barbotage were studied. Gas chromatography, emission spectroscopy, high-speed photography, and shadow photography were used for diagnosis. The results demonstrated the dependence of hydrogen yield on the flow rates of Ar, He, and CO2. The maximum yield values of hydrogen were 791 mL/min and 811 mL/min, while the maximum energy efficiency reached 135.6 NL/kWh and 162.2 NL/kWh in Nefras with Ar and He barbotage, respectively. The dynamics of discharge structure and the rotational and vibrational temperatures of C2 molecules were studied.
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