Browse
Records Added in 2024
Records added in 2024
Change year: 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025
Filter by month: January | February | March | April | May | June | July | August | September | October | November | December
Showing records 101 to 125 of 1816. [First] Page: 1 2 3 4 5 6 7 8 9 Last
Three-Dimensional VOF-DEM Simulation Study of Particle Fluidization Induced by Bubbling Flow
Liming Liu, Mengqin Zhan, Rongtao Wang, Yefei Liu
August 28, 2024 (v1)
Keywords: bubble–particle collision, bubbling flow, fluidization, particle suspension, VOF-DEM
The bubbling flow plays a key role in gas−liquid−solid fluidized beds. To understand the intrinsic fluidization behaviors at the discrete bubble and particle scale, coupled simulations with the volume of fluid model and the discrete element method are performed to investigate the effects of the gas inlet velocity, particle properties and two-orifice bubbling flow on particle fluidization. Three-dimensional simulations are carried out to accurately capture the dynamic changes in the bubble shape and trajectory. A bubbling flow with a closely packed bed is simulated to study the onset of particle fluidization. The obvious phenomena of particle fluidization are presented by both the experiment and simulation. Although an increasing gas inlet velocity promotes particle fluidization, the good fluidization of particles cannot be achieved solely by increasing the gas inlet velocity. When the channel is packed with more particles, the bubbles take a longer time to pass through the higher parti... [more]
Analysis of the Processes of Paraffin Deposition of Oil from the Kumkol Group of Fields in Kazakhstan
Laura Boranbayeva, Galina Boiko, Andrey Sharifullin, Nina Lubchenko, Raushan Sarmurzina, Assel Kozhamzharova, Serzhan Mombekov
August 28, 2024 (v1)
Subject: Materials
Keywords: alkanes, asphalt–resin–paraffin deposits (ARPDs), crystal formation, oil mixtures, paraffins, rheological characteristics
The oil pipeline transportation of highly waxy oils when it is cold is accompanied by the deposition of paraffins in the inner surface of the pipeline. This study of the initial properties of the oil; the composition, structure, and nature of the components of normal alkanes in oil; and their influence on the aggregative stability of the resulting system makes it possible to find the best solutions to optimize the conditions of oil transportation with the lowest energy costs. This study shows that, according to the content of solid paraffin (14.0−16.2%), the oils of the Kumkol group of fields in Kazakhstan are highly waxy. They are characterized by high yield loss temperature values (+9−+12 °C), which also correlate with the values of the rheological parameters (τ0 1.389 Pa, 3.564 Pa). The influence of the temperature and shear rate on the shear stress and effective viscosity of the initial oils was studied. At temperatures below 20 °C, depending on the shear rate, there is an increase... [more]
Research of the Influence of Lateral Inflow Angles on the Cavitation Flow and Movement Characteristics of Underwater Moving Objects
Rishan Xie, Huixia Jia, Jiawei Chen, Lite Zhang, Chengwei Zhang
August 28, 2024 (v1)
Keywords: hydrodynamic characteristics, lateral inflow angle, parallel objects, series objects, supercavitation
This study examined the multi-phase flow field for a single object and two parallel/series objects under different incoming angles of lateral flow. The volume of fluid model, the Sauer−Schnerr cavitation model, and the six degrees of freedom (DOF) method were adopted to consider simulations of multi-phase flow, phase change, and object movement, respectively. The results show that, for a single object, the degree of asymmetry in the cavity profile depends on the component (the z-component) of the lateral inflow velocity in the direction perpendicular to the initial velocity of the object. As this component increases, the asymmetry of the cavity increases. The cavity length is related to the relative axial speed between the object and the water. For parallel objects, the cavity asymmetry is determined by the superimposed influence of the z-component of the lateral incoming speed and the high-pressure zone induced by the nearby object. The object located downstream relative to the latera... [more]
Performance Analysis and Optimization of Sub-Atmospheric Purging through Microcapillaries in an ICF Cryogenic Target
Cui Li, Shikai Yin, Zhiying Fu, Hao Wu, Yanzhong Li
August 28, 2024 (v1)
Keywords: evacuation, filling, inertial confinement fusion, microtube, numerical simulation
In inertial confinement fusion, the sub-atmospheric purging through microcapillaries is of great importance to the high gas purity inside the cryogenic target and the low failure rate of experiments. In this study, a non-continuous flow model is developed for this sub-atmospheric purging process and verified through National Ignition Facility experiments to study the evolution of parameters such as pressure and gas composition that are not possible to measure directly. The effects of microcapillary structures and sizes on the transient evacuation−filling behaviors are analyzed, and the periodic purging scheme is optimized. The results show that the extension of evacuation and filling time caused by the elongated microtube can be described as a linear function of microtube length or an exponential decay function of microtube diameter, and the change of the inner diameter has a more drastic effect. The conical-straight composite can effectively reduce the evacuation and filling time whil... [more]
Experimental Study of Plugging Agent Particle Size and Concentration on Temporary Plugging Fracturing in Shale Formation
Feng Yang, Qin Qian, Mingjing Lu, Wenjun He, Anhai Zhong, Zilin Zhang, Danyang Zhu, Yushi Zou
August 28, 2024 (v1)
Keywords: fracture morphology, shale, temporary plugging fracturing
During the temporary plugging fracturing (TPF) process, the pressure response and pumping behavior significantly differ from those observed during conventional fracturing fluid pumping. Once the temporary plugging agent (TPA) forms a plug, subsequent fracture initiation and propagation become more intricate due to the influence of the TPA and early fractures. Factors such as concentration, particle size, and ratio of the TPA notably affect the effectiveness of TPF. This study employs a true triaxial hydraulic fracturing simulation system to conduct TPF experiments with varying particle size combinations and concentrations at both in-fracture and in-stage locations. The impact of different TPA parameters on the plugging effectiveness is assessed by analyzing the morphology of the induced fractures and the characteristics of pressure curves post experiment. Results indicate that combining dfferent particle sizes enhances plugging effectiveness, with a combination of smaller and larger pa... [more]
Numerical Study on the Fracturing of Deep Rock Masses by Blasting Based on the Material Point Method
Hu Xiao, Meng Wang, Weiting Gao, Ming Zou, Yuntao Wang, Jinshan Sun
August 28, 2024 (v1)
Subject: Materials
Keywords: crack propagation, high in-situ stress, material point method, rock blasting
Blasting is a prevalent technique in deep rock excavation, with the state of rock fragmentation under high in-situ stress conditions being distinct from that under low in-situ stress conditions. A new material point method framework utilizing the generalized interpolated material point and convective particle domain interpolation functions was implemented to simulate the single-hole blasting process, analyze the stress distribution around the blasting hole, and elucidate the mechanism of how ground stress influences the expansion of blasting cracks through the interaction with the blasting load. In addition, the dynamic relaxation method realizes the stress’s initialization. It was concluded that the in-situ stress can increase the compressive stress induced by blasting load, whereas it decreases the caused tensile stress. With the increase in the ground stress, the scale of the cracks decreases. Under the non-isobaric condition, the blast-induced cracks preferentially expand along the... [more]
Discovery of Natural Compound-Based Lead Molecule against Acetyltransferase Type 1 Bacterial Enzyme from Morganella morgani Using Machine Learning-Enabled Molecular Dynamics Simulation
Meshari Alazmi, Olaa Motwalli
August 28, 2024 (v1)
Keywords: aacA7, M. morganii, molecular docking, molecular dynamics, virtual screening
Drug-resistant Morganella morganii, a rod-shaped, Gram-negative, facultatively anaerobic bacillus belonging to the Enterobacteriaceae family, is a growing worldwide health concern due to its association with high morbidity and mortality rates. Recent advancements in machine learning, particularly Alphafold 2’s protein structure prediction using local physics and pattern recognition, have aided research efforts. This study focuses on the enzymatic activity of aminoglycoside N6′-acetyltransferase (aacA7), a critical transferase enzyme in bacteria that confers resistance to aminoglycosides. AacA7 modifies aminoglycoside molecules by catalyzing the acetylation of their 6′-amino group using acetyl-CoA, rendering antibiotics like kanamycin, neomycin, tobramycin, and amikacin inactive. We propose that Doripenem and OncoglabrinolC can interact with aacA7, potentially modifying its enzymatic activity. Molecular docking analysis of aacA7 with 22 drug targets revealed OncoglabrinolC as the most p... [more]
Material Removal and Surface Modification of Copper under Ultrasonic-Assisted Electrochemical Polishing
Xinqian Zhang, Jinhu Wang, Jiaqi Chen, Binghai Lyu, Julong Yuan
August 28, 2024 (v1)
Subject: Materials
Keywords: cavitation, copper, electrochemical polishing, passivation, ultrasonic assisted machining
Electrochemical polishing exhibits high efficiency and simplicity of operation and presents broad prospects in metal field processing. However, the poor conductivity of the surface oxides generated during electrochemical polishing may lead to uneven electrolysis and surface protrusions if not promptly removed. This study combined ultrasonic treatment with electrochemical polishing and adjusted the angle of the ultrasonic jet to investigate the effect of ultrasonic-assisted electrochemical polishing on the removal of protruding microstructures. The study examined the surface morphology, hardness, residual stress, and workpiece contact angle before and after processing. The results demonstrated that ultrasonic assistance can effectively promote electrochemical reactions and improve the removal efficiency of the workpiece surface. With an increase in ultrasonic power and processing time, the corrosion potential of the workpiece decreased, which accelerated the material removal rate. The r... [more]
Relation of the Content of Sustainable Components (HEFAs) in Blends with Hydrotreated Straight-Run Kerosene to the Properties of Aviation Fuel
Rosen Dinkov, Dicho Stratiev, Ivo Andreev, Georgi Georgiev, Magdalena Angelova, Rositsa Zhivkova Dimitrova, Vesislava Toteva
August 28, 2024 (v1)
Subject: Materials
Keywords: corrosion, electrical conductivity, existent gum, GHG emissions, HEFA-SPK, kerosene, SAF, water separation
An expected increase in the demand for aviation transport service will result in the deterioration of the environment and human health, respectively, due to extra greenhouse gas (GHG) emissions. Concerns from EU institutions about the issue have led to legislation initiatives and, later, to development of Regulation (EU) 2023/2405 for the reduction of GHG emissions via the substitution of fossil kerosene with an increasing share of sustainable components. Hydroprocessed esters and fatty acids (HEFAs) are the most commercially acceptable sustainable alternative but their influence on aviation fuel properties needs to be further evaluated in terms of all required and extended properties, as per ASTM D1655. The main properties, together with the rarely reported upon existent gum, water separation, corrosion, and the electrical conductivity of HEFAs and their blends with fossil kerosene were quantitatively evaluated in this study. For every increase of 10% (v/v) of HEFAs, the following fue... [more]
Two-Stage Distributed Robust Optimal Allocation of Integrated Energy Systems under Carbon Trading Mechanism
Ruicheng Dai, Xiang Zhang, Hongbo Zou
August 28, 2024 (v1)
Subject: Optimization
Keywords: column and constraint generation (C&CG) algorithm, integrated energy system (IES), ladder carbon trading mechanism, photovoltaic output uncertainty, two-stage distributed robust optimization (DRO)
The development of renewable energy and the construction of a comprehensive energy system with multiple complementary energy sources have gradually become the main direction of China’s energy development. As the penetration rate of renewable energy increases, the intermittent and fluctuating output of wind and solar power has a more significant impact on the system. This article conducts research on the optimization configuration of integrated energy system (IES) considering photovoltaic output uncertainty under a ladder carbon trading mechanism. Firstly, a two-stage distributed robust optimization (DRO) configuration model for integrated energy system is established. In detail, a deterministic model aimed at minimizing investment costs is given in the first stage and an uncertainty model aimed at minimizing operating costs in the probability distribution of the worst scenario is built in the second stage. Then, a data-driven distributed robust optimization method is adopted to deal wi... [more]
Characterization and Performance Evaluation of Digital Light Processing 3D Printed Functional Anion Exchange Membranes in Electrodialysis
Xue Yu, Hongyi Yang, Xinran Lv, Xin Zhang, Veeriah Jegatheesan, Xiaobin Zhou, Yang Zhang
August 28, 2024 (v1)
Subject: Materials
Keywords: 3D printing, anion exchange membrane, desalination, electrodialysis, functional
With the rapid development of 3D printing technologies, more attention has been focused on using 3D printing for the fabrication of membranes. This study investigated the application of digital light processing (DLP) 3D printing combined with quaternization processes to develop dense anion exchange membranes (AEMs) for electrodialysis (ED) separation of Cl− and SO42− ions. It was discovered that at optimal curing times of 40 min, the membrane pore density was significantly enhanced and the surface roughness was reduced, and this resulted in an elevation of desalination rates (97.5−98.7%) and concentration rates (165.8−174.1%) of the ED process. Furthermore, increasing the number of printed layers improved the membranes’ overall polymerization and performance, with double-layer printing showing superior ion flux. This study also highlights the impact of the polyethylene glycol diacrylate (PEGDA) molecular weight on membrane efficacy, where PEGDA-700 outperformed PEGDA-400 in ion transpo... [more]
Design and Experiments of the Data Acquisition System for Bale Rolling Characteristic Parameters on a Large-Scale Round Bale Machine
Junyue Wang, Fandi Zeng, Ji Cui, Hongbin Bai, Xuying Li, Zhihuan Zhao
August 28, 2024 (v1)
Keywords: bale rolling characteristics, data acquisition, power consumption, radial tension, round bale machine, straw bale
The parameters of the roll characteristics of a large-scale round bale machine were collected in real time to investigate the bale rolling mechanism. This investigation develops a set of adaptable and highly integrated data acquisition systems for the bale rolling performance parameters of large-type round bale machines. A rolling experiment is conducted using sunflower straw as the material, and the power consumption and radial tension of the roller-round bale machine during the bale rolling process are studied. In the grass core formation stage, the round bale machine’s torque need was minimal, the radial tension of the bale remained nearly constant, and the bale chamber was primarily filled with loose sunflower straw. The motor torque and the straw bale’s radial tension both showed a tendency of gradual increase when the round bale machine was in the grass-filling stage. The motor torque and bale radial tension displayed a roughly linear trend of rapid rise as the sunflower straw co... [more]
Optimizing Elemental Transfer Predictions in Submerged Arc Welding via CALPHAD Technology under Varying Heat Inputs: A Case Study into SiO2-Bearing Flux
Jun Fan, Jin Zhang, Dan Zhang
August 23, 2024 (v1)
Subject: Materials
Keywords: heat input, material design, SiO2-bearing flux, weld metal, welding process
With the advancement of the manufacturing industry, performing submerged arc welding subject to varying welding heat inputs has become essential. However, traditional thermodynamic models are insufficient for predicting the effect of welding heat input on elemental transfer behavior. This study aims to develop a model via CALPHAD technology to predict the influence of heat input on essential elements such as O, Si, and Mn when typical SiO2-bearing fluxes are employed. The predicted data demonstrate that the proposed model effectively forecasts changes in elemental transfer behavior induced by varying welding heat inputs. Furthermore, the study discusses the thermodynamic factors affecting elemental transfer behavior under different heat inputs, supported by both measured compositions and thermodynamic data. These insights may provide theoretical and technical support for flux design, welding material matching, and composition prediction under various heat input conditions subject to su... [more]
Developing Lead Compounds of eEF2K Inhibitors Using Ligand−Receptor Complex Structures
Jiangcheng Xu, Wenbo Yu, Yanlin Luo, Tiantao Liu, An Su
August 23, 2024 (v1)
Keywords: deep generative model, drug discovery, eEF2K inhibitor, molecular docking
The eEF2K, a member of the α-kinase family, plays a crucial role in cellular differentiation and the stability of the nervous system. The development of eEF2K inhibitors has proven to be significantly important in the treatment of diseases such as cancer and Alzheimer’s. With the advancement of big data in pharmaceuticals and the evolution of molecular generation technologies, leveraging artificial intelligence to expedite research on eEF2K inhibitors shows great potential. Based on the recently published structure of eEF2K and known inhibitor molecular structures, a generative model was used to create 1094 candidate inhibitor molecules. Analysis indicates that the model-generated molecules can comprehend the principles of molecular docking. Moreover, some of these molecules can modify the original molecular frameworks. A molecular screening strategy was devised, leading to the identification of five promising eEF2K inhibitor lead compounds. These five compound molecules demonstrated e... [more]
Fracture Propagation of Multi-Stage Radial Wellbore Fracturing in Tight Sandstone Reservoir
Yuning Yong, Zhaoquan Guo, Xiaoxia Zhou, Shouceng Tian, Ye Zhang, Tianyu Wang
August 23, 2024 (v1)
Keywords: finite element/meshfree method, fracture propagation, multi-stage hydraulic fracturing, radial wellbore
Radial wellbore fracturing is a promising technology for stimulating tight sandstone reservoirs. However, simultaneous fracturing of multiple radial wellbores often leads to unsuccessful treatments. This paper proposes a novel technology called multi-stage radial wellbore fracturing (MRWF) to address this challenge. A numerical model based on the finite element/meshfree method is established to investigate the effects of various parameters on the fracture propagation of MRWF, including the azimuth of the radial wellbore, the horizontal stress difference, and the rock matrix permeability. The results show that previously created fractures have an attraction for subsequently created fractures, significantly influencing fracture propagation. A conceptual model is proposed to explain the variations in the fracture propagation of MRWF, highlighting three critical effect factors: the attraction effect, the orientation effect of the radial wellbore, and the deflection effect of the maximum ho... [more]
Detecting Steam Leakage in Nuclear Power Systems Based on the Improved Background Subtraction Method
Jie Liu, Yanping Huang, Minglu Zhang, Suting Zhou, Changhua Nie, Minggang Li, Lin Zhang
August 23, 2024 (v1)
Keywords: high pressure, high temperature, improved background subtraction method, nuclear system, steam leakage
As a key system in nuclear power plants, nuclear power systems contain high-temperature, high-pressure water media. A steam leak, if it occurs, can at minimum cause system functional loss and at worst lead to casualties. Therefore, it is urgent to carry out steam leakage detection work for high-temperature, high-pressure loop systems. Currently, steam leaks are primarily detected through visual monitoring and pressure gauges. However, if there is a minor leak under high system pressure, the slight decrease in pressure may not be enough to alert the operators, leading to a delay in detecting the steam leak. Thus, this detection method has certain drawbacks. In view of these issues, this paper introduces computer vision technology to monitor the high-temperature, high-pressure loop system and proposes the use of an improved background subtraction method to detect steam leaks in the loop system. The results show the following advantages of this method: (1) It can effectively identify stea... [more]
Identification of Multi-Parameter Fluid in Igneous Rock Reservoir Logging—A Case Study of PL9-1 in Bohai Oilfield
Jiakang Liu, Kangliang Guo, Shuangshuang Zhang, Xinchen Gao, Jiameng Liu, Qiangyu Li
August 23, 2024 (v1)
Keywords: Bohai Bay Basin, comprehensive logging, FI, fluid identification, geochemical parameters, mesozoic igneous rock, PL9-1
Since the “13th Five-Year Plan”, the exploration of large-scale structural oil and gas reservoirs in the Bohai oilfield has become more complex, and the exploration of igneous oil and gas reservoirs has become the focus of current attention. At present, igneous rock reservoir fluid identification methods are mainly based on the evaluation method of logging single parameter construction, which is primarily a qualitative identification due to lithology, physical property, and engineering factors. Accurate acquisition of interference logging data, and multi-parameter coupling and recording coupling methods are few, lacking systematic and comprehensive evaluation and analysis of logging data. Since conventional logging data in the study area have difficulty accurately and quickly identifying reservoir fluid properties, a systematic analysis was conducted of three factors: lithology, physical properties, and engineering, as well as a variety of logging parameters (gas measurement, three-dim... [more]
Experimental Assessment of Paper Formation Conditions and Structural Two-Sidedness and Their Impacts on Curl Phenomena
Paulo A. N. Dias, Ricardo Rodrigues, Marco S. Reis
August 23, 2024 (v1)
Keywords: curl troubleshooting, dimensional stability, fiber orientation in ZD, image analysis, paper curl
Curl propensity is a critical-to-quality (CTQ) property of paper, as it causes severe problems during printing and other final conversion operations. The main papermaking factor causing the curl phenomenon is the existence of a fiber orientation (FO) gradient across the thickness direction (or ZD), also known as two-sidedness. Therefore, a methodology that characterizes the FO across the ZD is fundamental for papermakers. In this work, we propose and validate an efficient and cost-effective protocol based on sheet splitting and image analysis. Besides assessing the level of FO two-sidedness, the methodology also provides insights into the flow dynamics in the draining zone of the forming section of the paper machine and the drying stresses built into the paper. This information is relevant for monitoring, optimizing, and troubleshooting activities in the paper industry.
Implantable and Semi-Implantable Biosensors for Minimally Invasive Disease Diagnosis
Yameng Xu, Jingyuan Zhang, Wilson Z. Ray, Matthew R. MacEwan
August 23, 2024 (v1)
Subject: Materials
Keywords: biodegradable materials, fabrications, implantable and semi-implantable biosensors, mechanisms and strategies, nanomaterials
Implantable and semi-implantable biosensors fabricated with biodegradable materials and nanomaterials have gained interest in the past few decades. Functionalized biodegradable materials and nanomaterials are usually employed to satisfy clinical and research requirements because of their advanced properties. Novel fabrication techniques were developed to improve the efficiency and accuracy. Different working mechanisms were facilitated to design different types of sensors. This review discusses the recent developments of implantable and semi-implantable biosensors. The materials and fabrications are browsed, and different types of biomedical sensors for different variables are discussed as a focused topic. The biomedical sensors are discussed according to the targets and working mechanisms, followed by a focus on the nervous system sensing to provide an inspiration that different variables can be studied simultaneously on the single system. In the end, challenges and prospects will be... [more]
Mercury Discharge Inventory Based on Sewage Treatment Process in China
Chenglong Wei, Jiaxu Guo, Rongyang Fan, Tingting Zhang, Xianbin Wang, Hao Chen, Song Huang, Yufei Hu, Gang Zhang
August 23, 2024 (v1)
Subject: Environment
Keywords: domestic sewage, Hg emission status, movement and transformation of Hg, total estimation
Mercury pollution is a serious public health problem. China’s extensive use and reliance on mercury has led to water pollution, particularly the presence of methylmercury in water. Estimating total mercury emissions from wastewater in China is challenging due to the large amount and wide range of emissions. An estimation model for total mercury content in sewage in China was established by establishing a relationship between sewage treatment volume, mercury content in effluent after sewage treatment, and the data of sludge production and mercury content in the sewage treatment plant. It was determined that only 3% of mercury entered the air during sewage treatment, 27.5% of mercury entered the effluent, and about 69.5% of mercury entered the sludge, based on the treatment of existing wastewater treatment plants in China. From 2002 to 2021, the average annual sewage mercury emission in China was 32.07 Mg, and the emissions were higher in densely populated and economically developed prov... [more]
Industrial Catalytic Production Process of Erythromycin
Theodora Adamantidi, Ellie Panoutsopoulou, Evangelia Stavrakoudi, Panagiota Tzevelekou, Nikolaos C. Kokkinos
August 23, 2024 (v1)
Keywords: catalytic mechanism, COVID-19, cytochrome P450, erythromycin production
The impact of COVID-19’s unexpected outbreak forced the scientific community to seek alternative treatment methods in order to overcome the hindrance of traditional medicine in terms of alleviating the symptoms of this virus. Erythromycin, which was introduced in 1952, is an antibiotic that is reported to pose as an effective substitute medication for various ailments such as skin, respiratory, bone, and female reproductive conditions, and cancer, as well as the newly added COVID-19. The importance of both the erythromycin molecule and the catalyst of its production, namely P450eryF of the cytochrome P450 family, in many health-concerned and environmentally related applications, has led several countries, the World Health Organization (WHO) and the health industry to recruit and cooperate with numerous universities and institutions, in an attempt to tackle the demand for efficient antibiotics. The aim of this study is to discuss and further analyze the overall structure and catalytic m... [more]
Assessing the Impact of Sustainable Pasture Systems on Lamb Meat Quality
Nikola Stanišić, Dragana Ružić-Muslić, Nevena Maksimović, Bogdan Cekić, Violeta Caro Petrović, Ivan Ćosić, Marina Lazarević
August 23, 2024 (v1)
Keywords: fatty acid composition, instrumental colour, lamb meat quality, mineral composition, supplemented pasture system
The global demand for sustainable lamb production is increasing due to the need for high-quality meat with minimal environmental impact, making the choice of feeding systems crucial. This study investigates the effects of supplemented pasture feeding during the last 60 days of rearing on the meat fatty acid profile, pH value, colour characteristics, and mineral composition of lambs, highlighting the benefits of such feeding systems. Ninety lambs (MIS sheep breed) were divided into three distinct feeding regimes: Group I (alfalfa and concentrate feeding), Group II (white clover [Trifolium repens] pasture with concentrate supplementation), and Group III (birds’ foot trefoil [Lotus corniculatus] pasture with concentrate supplementation). The results have shown that supplemented pasture feeding improves the fatty acid profile by increasing n-3 content and desirable fatty acids, while reducing the n-6/n-3 ratio and atherogenic index (p < 0.05), particularly in lambs finished on an L. cor... [more]
Research on Gas Control Technology in Goaf Based on the Influence of Mining Speed
Cheng Cheng, Xiao-Yu Cheng, Long Chen, Xing-Ying Ma
August 23, 2024 (v1)
Keywords: gas extraction, high-level borehole optimization, mining speed, mining-induced fractures, numerical simulation
To comprehensively understand the influence of mining speed on gas emissions in goaf during coal seam extraction, enhance gas extraction efficiency in goaf, manage gas emissions at the working face, and ensure safety in the mining production process. This study focuses on the No. 3 mining area of Wangjialing Mine, employing numerical simulations to analyze the evolution of mining-induced fractures and the characteristics of gas distribution in the overburden at varying mining speeds. Furthermore, by integrating actual gas emission and extraction data at the production face, this study examines the quantitative relationship between mining speed and gas emissions in the goaf, identifying optimal regions for high-position borehole layouts and conducting borehole optimization design and investigation. The results of this study indicate that the initial caving step distance of the goaf roof increases with the advancement speed of the working face. Conversely, the maximum height of through f... [more]
LSMOF-AD: Three-Stage Optimization Approach with Adaptive Differential for Large-Scale Container Scheduling
Mingshan Chen, Weichao Ding, Mengyang Zhu, Wen Shi, Guoqing Jiang
August 23, 2024 (v1)
Keywords: adaptive differential evolution, container scheduling, large-scale optimization, multi-objective optimization
Container technology has gained a widespread application in cloud computing environments due to its low resource overhead and high flexibility. However, as the number of containers grows, it becomes increasingly challenging to achieve the rapid and coordinated optimization of multiple objectives for container scheduling, while maintaining system stability and security. This paper aims to overcome these challenges and provides the optimal allocation for a large number of containers. First, a large-scale multi-objective container scheduling optimization model is constructed, which involves the task completion time, resource cost, and load balancing. Second, a novel optimization algorithm called LSMOF-AD (large-scale multi-objective optimization framework with muti-stage and adaptive differential strategies) is proposed to effectively handle large-scale container scheduling problems. The experimental results show that the proposed algorithm has a better performance in multiple benchmark p... [more]
Leakage Quantification in Metallic Pipes under Different Corrosion Exposure Times
Alaa Agala, Muhammad A. Khan, Feiyang He, Abdulaaziz Alnuman
August 23, 2024 (v1)
Subject: Materials
Keywords: corrosion time, crack, crack propagation, degradation mechanism, leakage, pipe failure, pressure, stress
The combined effects of aqueous corrosion, stress factors, and seeded cracks on leakage in cast iron pipes have not been thoroughly examined due to the complexity and difficulty in predicting their interactions. This study seeks to address this gap by investigating the interdependencies between corrosion, stress, and cracks in cast iron pipes to optimise the material selection and design in corrosive environments. Leakage experiments were conducted under simulated localised corrosive conditions and internal pressure, revealing that leakage increased from 0 to 25 mL with crack sizes of 0.5 mm, 0.8 mm, 1 mm, and 1.2 mm, along with corrosion times of 0, 120, 160, and 200 h, and varying stress levels. An empirical model was developed using a curve-fitting approach to map the relationships among corrosion time, crack propagation, and leakage amount. The results demonstrate that the interaction between corrosion, stress, and crack propagation was complex and nonlinear, and the leakage amount... [more]
Showing records 101 to 125 of 1816. [First] Page: 1 2 3 4 5 6 7 8 9 Last
Change year: 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025
Filter by month: January | February | March | April | May | June | July | August | September | October | November | December