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Records Added in August 2024
Records added in August 2024
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Showing records 126 to 150 of 506. [First] Page: 2 3 4 5 6 7 8 9 10 Last
Optimized Ultrasonic Extraction of Essential Oil from the Biomass of Lippia graveolens Kunth Using Deep Eutectic Solvents and Their Effect on Colletotrichum asianum
Juan Pablo Manjarrez-Quintero, Octavio Valdez-Baro, Raymundo Saúl García-Estrada, Laura Aracely Contreras-Angulo, Pedro de Jesús Bastidas-Bastidas, J. Basilio Heredia, Luis Angel Cabanillas-Bojórquez, Erick Paul Gutiérrez-Grijalva
August 23, 2024 (v1)
Subject: Biosystems
Keywords: antifungal activity, deep eutectic solvents, essential oils, Lippia graveolens, Mexican oregano, ultrasound-assisted extraction
Essential oils are emerging as alternatives to conventional pest control chemicals. Lippia graveolens Kunth (Mexican oregano) is a source of essential oils and during conventional extraction, the biomass generated is discarded as waste; however, reports show that this biomass is still a rich source of essential oils. Conventional essential oil extraction causes contamination and utilizes toxic solvents. Deep eutectic solvents (DESs) offer low toxicity, biodegradability, high selectivity, and yields comparable to organic solvents. This study obtained essential oil from Lippia graveolens biomass via hydrodistillation with ultrasound-assisted DES pretreatment. This research aimed to optimize the extraction of essential oil from Lippia graveolens biomass using ultrasound-assisted DESs and assess its in vitro and in vivo inhibitory effect on C. asianum. The response variables were extraction yield and total reducing capacity. Optimal conditions were determined using a central composite rota... [more]
A Self-Adaption Growth Model for the Burden Packing Process in a Bell-Less Blast Furnace
Dongling Wu, Fengjie Yao, Duoyong Zhang, Enxue Zu, Ping Zhou, Wei Chen
August 23, 2024 (v1)
Subject: Materials
Keywords: blast furnace, burden distribution, Discrete Element Method (DEM), flow trajectory, packing model
The burden structure directly decides the distribution of gas flow inside a blast furnace (BF). Falling, stacking, and descending bulk materials are the three main processes for burden formation, among which the stacking process plays a decisive role. The Discrete Element Method (DEM) and theoretical modelling were combined to predict stacking behavior in this study. Falling and stacking behaviors were first simulated based on DEM. The repose angle during the stacking process and mass fraction distribution in the radial direction were analyzed. Then, the upper, centroid, and lower trajectory falling lines were determined, and a polynomial relation was found between the angle and the packing height. The influences of three parameters on the repose angle were investigated. Compared with the natural repose angle and chute inclination angle, the effects of the trajectory line depth appeared trivial. The polynomial relation between the repose angle and the packing height was specified to be... [more]
Research and Application of Gangue for the Preparation of Polymerized Aluminum Magnesium Chloride Flocculant
Chaofen Yang, Xiaofeng Ma, Gang Ma, Lunqiu Zhang, Guang Lu, Yifan Zhang, Dantong Geng, Xiaolong You, Huan Liu, Yueyao Tian
August 23, 2024 (v1)
Keywords: coal gangue, COD removal rate, polymeric aluminum magnesium chloride, turbidity removal
Polymerized aluminum magnesium chloride (PAMC) flocculant was prepared from gangue as a raw material, and the effects of pH, the polymerization time, and the polymerization temperature on the performance of the PAMC were investigated by a one-factor test, based on which, orthogonal experiments (three-factor and two-level) were conducted to optimize the relevant parameters. Meanwhile, FTIR and SEM were used to characterize the polymerized aluminum magnesium chloride, and the sample was applied in printing and dyeing wastewater treatment. The results showed that a pH value of 2.2 and a reaction at 60 °C for 4.5 h were the optimal preparation conditions; the characterization analysis showed that the synthesized product was polymerized aluminum magnesium chloride; the turbidity removal rate of the PAMC for printing and dyeing wastewater was increased by 2.1%, the COD removal rate was increased by 3.1%, the ammonia nitrogen removal rate was increased by 2.1%, and the chromaticity removal ra... [more]
A Fault Direction Criterion Based on Post-Fault Positive-Sequence Information for Inverter Interfaced Distributed Generators Multi-Point Grid-Connected System
Fan Yang, Hechong Chen, Gang Han, Huiran Xu, Yang Lei, Wei Hu, Shuxian Fan
August 23, 2024 (v1)
Keywords: direction criterion, flexible operation mode, IIDG, positive-sequence component, renewable energy system
In response to the poor reliability in identifying fault direction in distribution networks with Inverter Interfaced Distributed Generators (IIDGs), considering the control strategy of low-voltage ride-through, a fault direction criterion based on post-fault positive-sequence steady-state components is proposed. Firstly, the output steady-state characteristics of IIDGs considering the low-voltage ride-through capability are analyzed during grid failure, and the applicability of existing directional elements in a distribution network with IIDGs connected dispersively is demonstrated. Subsequently, for the typical structure of an active distribution grid operating under flexible modes, the positive-sequence voltage and current are examined in various fault scenarios, and a reliable direction criterion is suggested based on the difference in post-fault positive-sequence impedance angles on different sides of the lines that are suitable whether on the grid side or the IIDG side. Lastly, th... [more]
Enhancement of Tensile Strength of Coconut Shell Ash Reinforced Al-Si Alloys: A Novel Approach to Optimise Composition and Process Parameters Simultaneously
M. Poornesh, Shreeranga Bhat, Pavana Kumara Bellairu, Olivia McDermott
August 23, 2024 (v1)
Subject: Materials
Keywords: coconut shell ash, cylinder liners, functionally graded material, mixture methodology, tensile strength
The research presents a novel approach to develop high-strength functionally graded composite materials (FGCMs) by using recycled coconut shell ash (CSA) particles as reinforcement for a hypereutectic Al-Si alloy matrix. Using a centrifugal casting technique, test specimens are prepared for the study under ASTM standards. The optimal combination of materials to maximise the materials’ overall tensile strength is obtained through the mixture methodology approach. The results show that CSA particles in the matrix material increase the tensile strength of the produced material. Process parameters, melting temperature and rotating speed were found to play a pivotal role in determining the tensile strength. A better tensile strength of the material is obtained when Al-Si = 90.5 wt%, CSA = 9.5 wt%, rotating speed = 800 RPM, and melting temperature = 800 °C; the proposed regression model developed has substantial predictability for tensile strength. This work presents a methodology for enhanc... [more]
Direct Epoxidation of Hexafluoropropene Using Molecular Oxygen over Cu-Impregnated HZSM-5 Zeolites
Jie-Ming Huang, Jingning Guo, Chengmiao Xu, An Su, Ke-Jun Wu, Chao-Hong He
August 23, 2024 (v1)
Subject: Materials
Keywords: epoxidation, hexafluoropropene, hexafluoropropylene oxide, modified HZSM-5
This study explores a novel method of directly epoxidizing hexafluoropropene with molecular oxygen under gaseous conditions using a Cu/HZSM-5 catalytic system (Cu/HZ). An in-depth investigation was conducted on the catalytic performance of Cu-based catalysts on various supports and Cu/HZ catalysts prepared under different conditions. Cu/HZ catalysts exhibited better catalytic performance than other porous medium-supported Cu catalysts for the epoxidation of hexafluoropropene by molecular oxygen. The highest propylene oxide yield of 35.6% was achieved over the Cu/HZ catalyst prepared under conditions of 350 °C with a Cu loading of 1 wt%. By applying characterization techniques including XRD, BET, NH3-TPD, and XPS to different catalyst samples, the relationship between the interaction of Cu2+ and HZSM-5 and the reactivity of the catalyst was studied, thereby elucidating the influence of calcination temperature and loading on the reactivity. Finally, we further proposed the possible mecha... [more]
Optimization Analysis of Various Parameters Based on Response Surface Methodology for Enhancing NOx Catalytic Reduction Performance of Urea Selective Catalytic Reduction on Cu-ZSM-13 Catalyst
Weiqi Li, Jie Wu, Dongwei Yao, Feng Wu, Lei Wang, Hua Lou, Haibin He, Jingyi Hu
August 23, 2024 (v1)
Keywords: ammonia storage characteristics, diesel engine, NOx conversion efficiency, SCR system
While selective catalytic reduction (SCR) has long been indispensable for nitrogen oxide (NOx) removal, optimizing its performance remains a significant challenge. This study investigates the combined effects of structural and intake parameters on SCR performance, an aspect often overlooked in previous research. This paper innovatively developed a three-dimensional SCR channel model and employed response surface methodology to conduct an in-depth analysis of multiple key factors. This multidimensional, multi-method approach enables a more comprehensive understanding of SCR system mechanics. Through target optimization, we achieved a simultaneous improvement in three critical indicators: the NOx conversion rate, pressure drop, and ammonia slip. It is worth noting that the NOx conversion rate has been optimized from 17.07% to 98.25%, the pressure drop has been increased from 3454.62 Pa to 2558.74 Pa, and the NH3 slip has been transformed from 122.26 ppm to 17.49 ppm. These results not on... [more]
Review of Hydrogen-Driven Power-to-X Technology and Application Status in China
Yunchu Zhai, Yong He, Jiaming Shao, Weiling Zhang, Xiaofan Tong, Zhihua Wang, Wubin Weng
August 23, 2024 (v1)
Subject: Energy Policy
Keywords: application, power-to-ammonia, power-to-hydrogen, power-to-methanol, power-to-X
Given China’s ambition to realize carbon peak by 2030 and carbon neutralization by 2060, hydrogen is gradually becoming the pivotal energy source for the needs of energy structure optimization and energy system transformation. Thus, hydrogen combined with renewable energy has received more and more attention. Nowadays, power-to-hydrogen, power-to-methanol, and power-to-ammonia are regarded as the most promising three hydrogen-driven power-to-X technologies due to the many commercial or demonstration projects in China. In this paper, these three hydrogen-driven power-to-X technologies and their application status in China are introduced and discussed. First, a general introduction of hydrogen energy policies in China is summarized, and then the basic principles, technical characteristics, trends, and challenges of the three hydrogen-driven power-to-X technologies are reviewed. Finally, several typical commercial or demonstration projects are selected and discussed in detail to illustrat... [more]
A Preliminary Study on Determining Seasonal Variations in Halloumi Cheese Using Near-Infrared Spectroscopy and Chemometrics
Maria Tarapoulouzi, José-Antonio Entrenas, Dolores Pérez-Marín, Ioannis Pashalidis, Charis R. Theocharis
August 23, 2024 (v1)
Subject: Materials
Keywords: chemometrics, classification, Halloumi cheese, NIR spectroscopy, PLS-DA, season
Cheese quality is affected by seasonal variations. These variations can influence several aspects of cheese, including its flavor, texture, nutritional content, and overall sensory qualities. The aim of this study was to assess the performance of near-infrared (NIR) instrumentation in terms of its ability to detect seasonal variations in Halloumi cheese samples when applying limited sample preparation compared to traditional protocols. Therefore, the use of NIR spectroscopy was examined for the determination of seasonal variations in Halloumi cheese samples from Cyprus in combination with chemometrics. Partial Least Squares Discriminant Analysis (PLS-DA) was applied. We found that NIR and chemometrics successfully discriminated the Halloumi cheese samples based on different climate conditions, the four seasons in the year when the milk collection took place. To externally validate the model, the dataset was divided into training and test sets. The innovation of this study is that Hallo... [more]
Prediction of Short-Term Winter Photovoltaic Power Generation Output of Henan Province Using Genetic Algorithm−Backpropagation Neural Network
Dawei Xia, Ling Li, Buting Zhang, Min Li, Can Wang, Zhijie Gong, Abdulmajid Abdullahi Shagali, Long Jiang, Song Hu
August 23, 2024 (v1)
Keywords: back propagation, Genetic Algorithm, photovoltaic power generation, prediction accuracy, rain and snow weather
In the low-carbon era, photovoltaic power generation has emerged as a pivotal focal point. The inherent volatility of photovoltaic power generation poses a substantial challenge to the stability of the power grid, making accurate prediction imperative. Based on the integration of a backpropagation (BP) neural network and a genetic algorithm (GA), a prediction model was developed that contained two sub-models: no-rain and no-snow scenarios, and rain and snow scenarios. Through correlation analysis, the primary meteorological factors were identified which were subsequently utilized as inputs alongside historical power generation data. In the sub-model dedicated to rain and snow scenarios, variables such as rainfall and snowfall amounts were incorporated as additional input parameters. The hourly photovoltaic power generation output was served as the model’s output. The results indicated that the proposed model effectively ensured accurate forecasts. During no-rain and no-snow weather con... [more]
Research on Operation Optimization of Fluid Sampling in Wireline Formation Testing with Finite Volume Method
Lejun Wu, Junhua Wang, Haibo Liu, Rui Huang, Huizhuo Xie, Xiaodong Li, Xuan Li, Jinhuan Liu, Changjie Zhao
August 23, 2024 (v1)
Keywords: finite volume method, fluid sampling, numerical simulation, operation optimization, wireline formation testing
Wireline formation testing is an important technique in the exploration and development of oil fields. Not only can real fluid samples be prepared from the formation directly obtained to know exactly whether the oil existed in the formation or not, but it can also show flowing pressure change to determine the production capacity of the formation. So, it is an important measurement method for formation evaluation during the drilling process and supports activities related to the exploration and development of oil fields. A numerical simulation model in this article is researched and established based on the finite volume method considering the influence of sensitive parameters such as reservoir heterogeneity, probe suction area, and mud-filtrate invasion depth during the drilling. The model is capable of designing and evaluating formation fluid sampling operations by calculating hydrocarbon content and flowing pressure. Furthermore, through case application, the performance and effect o... [more]
The Micropore Characteristics and Geological Significance of a Tuffaceous Tight Reservoir Formed by Burial Dissolution: A Case Study of the Carboniferous Tuff in the Santanghu Basin, NW China
Jian Ma, Yongshuai Pan, Zhongzheng Tong, Guoqiang Zhang
August 23, 2024 (v1)
Keywords: burial dissolution, micropore, tight reservoir, tuff
As a distinct type of reservoir, tuffaceous tight reservoirs have attracted much attention. However, previous studies on tuffaceous tight reservoirs formed in the burial diagenetic stage are few, particularly regarding the genesis of micropores, which restricts the in-depth exploration of tuffaceous tight oil. According to thin section observation, scanning electron microscopy (SEM) identification, X-ray diffraction (XRD) experiments, elemental analyses, porosity and permeability tests, and pore structure analyses, the micropore characteristics of the Carboniferous tuffaceous tight reservoir formed by burial dissolution in the Santanghu Basin, NW China, are studied. In addition, the cause of the tuff micropore formation and its geological significance are also researched in this paper. The results are as follows: (1) The tuffaceous tight reservoir formed by burial dissolution mainly consists of quartz, feldspar, dolomite, and clay minerals. The reservoir space mainly consists of interg... [more]
Study on the Damage Evolution and Failure Mechanism of Floor Strata under Coupled Static-Dynamic Loading Disturbance
Hailong Li, Haibo Bai, Wenjie Xu, Bing Li, Peitao Qiu, Ruixue Liu
August 23, 2024 (v1)
Keywords: B-G damage model, coupled static-dynamic loading, damage and fracture criterion, floor stress distribution state, mining-induced rock mechanics
In the field test, we found that the failure depth of the goaf floor strata tends to be further because the periodic breaking and caving of the immediate roof, upper roof, and roof key stratum has dynamic stress disturbance effects on the floor. To further analyze its formation mechanism, this paper studies the damage evolution and fracture mechanism of goaf floor rock under the coupled static-dynamic loading disturbance caused by roof caving, based on the stress distribution state, the damage evolution equation of coal measure rock, the damage constitutive model, and the fracture criterion of floor rock. The main conclusions are listed as follows: 1. Based on the mining floor stress distribution, the floor beam model establishes the response mechanism of floor rock stress distribution. Also, the equation of stress distribution at any position in floor strata under mining dynamic load is given. 2. Combining the advantages of Bingham and the Generalized-Boydin model, the B-G damage cons... [more]
Digital Twin for Monitoring the Experimental Assembly Process Using RFID Technology
Jakub Demčák, Kamil Židek, Tibor Krenický
August 23, 2024 (v1)
Keywords: control, digital twin, digitalization, manufacturing system, monitoring, RFID, Tecnomatix Plant Simulation
Despite the considerable advances that industrial manufacturing has undergone as a result of digitalization, the real-time monitoring of assembly processes continues to present a significant technical challenge. This article presents a solution to this problem by integrating digital twin technology with radio frequency identification (RFID) in order to improve the monitoring and optimization of assembly processes. The objective of this research is to develop a methodology that ensures synchronized data exchange between physical components and their digital counterparts using RFID for improved visibility and accuracy. The methodology entails the configuration of radio frequency identification systems to track the positions of products on conveyor belts, thereby facilitating real-time monitoring and the prompt detection of any deviations. This integration enhances remote monitoring capabilities and markedly optimizes assembly processes in comparison to traditional methods. The research f... [more]
Cloning, Expression and Enzymatic Characterization of Pectin Methyl Esterase from Populus trichocarpa and Its Application
Yanjiao Feng, Lifen Huang, Yue Zeng, Yiyuan Zhang, Wei Liu, Gang He
August 23, 2024 (v1)
Subject: Materials
Keywords: enzymatic characterization, molecular cloning, pectin methyl esterase, Populus trichocarpa
The pectin methyl esterase gene from Populus trichocarpa (PtPME) was successfully cloned through PCR amplification and subsequently inserted into the expressing vector pMAL-c5e for successful expression in Escherichia coli BL21 (DE3). Initially, we determined the primary enzymatic properties of PtPME, a pectin methyl esterase derived from Populus trichocarpa. Notably, this enzyme exhibits a higher affinity towards citrus pectin, with an esterification degree exceeding 60%. Furthermore, this enzyme’s optimal reaction temperature and pH were found to be 30 °C and 8, respectively. Importantly, its exceptional stability under neutral conditions highlights its potential application in the industrial production of low-ester pectin.
Matrix-Metalloproteinase-Responsive Brain-Derived Neurotrophic Factor for Spinal Cord Injury Repair
Jiaxiong He, Hui Cai, Yuanyuan Wang, Junyan Yan, Caixia Fan
August 23, 2024 (v1)
Subject: Biosystems
Keywords: brain-derived neurotrophic factor (BDNF), matrix metalloproteinases (MMPs), on-demand release, spinal cord injury repair
Brain-derived neurotrophic factor (BDNF) plays a vital role in supporting neuronal survival, differentiation, and promoting synaptogenesis, thereby facilitating synaptic plasticity in the central nervous system. Administration of exogenous BDNF is a crucial approach for treating central nervous system injuries. However, the inability of sustained drug release to match disease activity often leads to insufficient drug accumulation in the injured area (ineffectiveness) and severe side effects induced by the drug (toxicity). Matrix metalloproteinases (MMPs), especially MMP-2 and MMP-9, are typically upregulated after tissue damage, and their upregulated expression levels represent the degree of disease activity. In this study, we utilized bioengineering techniques to prepare a BDNF that can specifically bind to collagen and be released in response to MMP substrate cleavage (collagen binding domain tissue inhibitor of matrix metalloproteinases brain-derived neurotrophic factor, CBD-TIMP-BD... [more]
Integrated Application of Dynamic Risk-Based Inspection and Integrity Operating Windows in Petrochemical Plants
Zhiyuan Han, Juanbo Liu, Jun Li, Haoyuan Kang, Guoshan Xie
August 23, 2024 (v1)
Keywords: crude distillation unit, dynamic risk-based inspection (DRBI), industrial application, integrity management, integrity operating windows (IOWs)
The scientific and reasonable maintenance strategy is critical to ensure the continuous operation of stationary equipment in the petrochemical industry; both risk-based inspection (RBI) and integrity operating windows (IOWs) are effective for stationary equipment maintenance. In traditional static RBI, the risk is assumed to remain constant in whole inspection period, and the latest variations of medium and process parameters are not fed back into risk calculation. Thus, risk value may be overestimated or underestimated, leading to unexpected failures or excessive inspection. Integrated application of dynamic risk-based inspection (DRBI) and IOWs is an advanced direction for this problem. However, due to the complexity of dynamic interaction mechanisms and risk assessment algorithms as well as the deficiency of powerful software, industrial applications of DRBI and IOWs are still limited. By proposing improved dynamic risk indexes and real-time monitoring process parameters as well as... [more]
The Seismic Identification of Small Strike-Slip Faults in the Deep Sichuan Basin (SW China)
Hai Li, Jiawei Liu, Majia Zheng, Siyao Li, Hui Long, Chenghai Li, Xuri Huang
August 23, 2024 (v1)
Keywords: fault distribution, fault identification, fault imaging, hidden fault, seismic processing method, strike-slip fault
Recently, the “sweet spot” of a fractured reservoir, controlled by a strike-slip fault, has been found and become the favorable target for economic exploitation of deep (>4500 m) tight gas reservoirs in the Sichuan Basin, Southwestern China. However, hidden faults of small vertical displacements (<20 m) are generally difficult to identify using low signal−noise rate seismic data for deep subsurfaces. In this study, we propose a seismic processing method to improve imaging of the hidden strike-slip fault in the central Sichuan Basin. On the basis of the multidirectional and multiscale decomposition and reconstruction processes, seismic information on the strike-slip fault can be automatically enhanced to improve images of it. Through seismic processing, the seismic resolution increased to a large extent enhancing the fault information and presenting a distinct fault plane rather than an ambiguous deflection of the seismic wave, as well as a clearer image of the sectional seismic attr... [more]
Exploring the Potential of Silicon Tetrachloride as an Additive in CO2-Based Binary Mixtures in Transcritical Organic Rankine Cycle—A Comparative Study with Traditional Hydrocarbons
Mashhour A. Alazwari, Muhammad Ehtisham Siddiqui
August 23, 2024 (v1)
Subject: Optimization
Keywords: binary mixtures, Carbon Dioxide, energy conversion systems, mixture optimization, organic rankine cycle, specific net power output, thermal efficiency
Carbon dioxide (CO2) has been recognized as one of the potential working fluids to operate power generation cycles, either in supercritical or transcritical configuration. However, a small concentration of some of the additives to CO2 have shown promising improvements in the overall performance of the cycle. The current study is motivated by the newly proposed additive silicon tetrachloride (SiCl4), and so we perform a detailed investigation of SiCl4 along with a few well-known additives to CO2-based binary mixtures as a working fluid in transcritical organic Rankine cycle setup with internal heat regeneration. The additives selected for the study are pentane, cyclopentane, cyclohexane, and silicon tetrachloride (SiCl4). A comprehensive study on the energy and exergy performance of the cycle for warm regions is conducted at a turbine inlet temperature of 250 °C. The performance of the heat recovery unit is also assessed to highlight its importance in comparison to a simple configuratio... [more]
Economic Optimization of Thermal Insulation Thickness for Insulated and Electrically Traced Pipelines in Drilling Applications
Meng Xu, Meng Gao, Ruitong Yang, Keping Wang, Zhe Yuan
August 23, 2024 (v1)
Subject: Environment
Keywords: electric heat tracing pipes, insulation pipes, insulation thickness optimization
This study presents an economic optimization model for determining the optimal insulation thickness for both thermal insulation and electric tracing pipelines. Using Life-Cycle Cost (LCC) analysis, optimization research was conducted under various working conditions to identify the most cost-effective insulation thickness. Factors such as pipe diameter, operational duration, drilling fluid temperature, and heat cost were analyzed to assess their impact on the economic thickness of the insulation layer, specifically within the unique environment of drilling sites. The results provide the economic thickness and total cost for both insulated and electrically traced pipelines under different scenarios. For instance, for a DN100 pipe with rock wool insulation operating for 3600 h, the economic thickness of the electrically traced pipe insulation was determined to be 5.18 cm greater per unit length compared to the non-electrically traced pipe, resulting in an additional cost of 19.36 CNY/m.... [more]
Classification Model for Real-Time Monitoring of Machining Status of Turned Workpieces
Fei Wu, Lai Yuan, Aonan Wu, Zhengrui Zhang
August 23, 2024 (v1)
Keywords: Bidirectional Long Short-Term Memory, deep learning, denoising autoencoders, state recognition, tool chatter, turning
The occurrence of tool chatter can have a detrimental impact on the quality of the workpiece. In order to improve surface quality, machining stability, and reduce tool wear cycles, it is essential to monitor the workpiece machining process in real time during the turning process. This paper presents a tool chatter state recognition model based on a denoising autoencoder (DAE) for feature dimensionality reduction and a bidirectional long short-term memory (BiLSTM) network. This study examines the feature dimensionality reduction method of the DAE, whereby the reduced-dimensional data are concatenated and input into the BiLSTM model for training. This approach reduces the learning difficulty of the network and enhances its anti-interference capability. Turning experiments were conducted on a SK50P lathe to collect the dataset for model performance validation. The experimental results and analysis indicate that the proposed DAE-BiLSTM model outperforms other models in terms of prediction... [more]
Dynamic Change Characteristics and Main Controlling Factors of Pore Gas and Water in Tight Reservoir of Yan’an Gas Field in Ordos Basin
Yongping Wan, Zhenchuan Wang, Meng Wang, Xiaoyan Mu, Jie Huang, Mengxia Huo, Ye Wang, Kouqi Liu, Shuangbiao Han
August 23, 2024 (v1)
Keywords: absorption of water vapor, gas–water distribution, nuclear magnetic resonance, tight reservoir, water saturation, Yan’an gas field
Tight sandstone gas has become an important field of natural gas development in China. The tight sandstone gas resources of Yan’an gas field in Ordos Basin have made great progress. However, due to the complex gas−water relationship, its exploration and development have been seriously restricted. The occurrence state of water molecules in tight reservoirs, the dynamic change characteristics of gas−water two-phase seepage and its main controlling factors are still unclear. In this paper, the water-occurrence state, gas−water two-phase fluid distribution and dynamic change characteristics of different types of tight reservoir rock samples in Yan’an gas field were studied by means of water vapor isothermal adsorption experiment and nuclear magnetic resonance methane flooding experiment, and the main controlling factors were discussed. The results show that water molecules in different types of tight reservoirs mainly occur in clay minerals and their main participation is in the formation... [more]
Catalytic Biomass Transformation to Hydrocarbons under Supercritical Conditions over Nickel Supported on Schungite
Elena O. Schipanskaya, Antonina A. Stepacheva, Mariia E. Markova, Alexey V. Bykov, Alexander I. Sidorov, Valentina G. Matveeva, Mikhail G. Sulman, Lioubov Kiwi-Minsker
August 23, 2024 (v1)
Keywords: deoxygenation, green diesel, Ni-catalyst, schungite support, stearic acid
Liquid fuel production from biomass-derived molecules has received great attention due to the diminished fossil fuel reserves, growing energy demand, and the necessity of CO2 emission reduction. The deoxygenation of oils and fatty acids is a promising process to obtain “green” diesel. Herein, we report the results of the study of the deoxygenation of stearic acid to alkanes as a model reaction. Series of Ni-supported on schungite were obtained by precipitation in subcritical water (hydrothermal deposition) and for comparison via wetness impregnation followed, in both cases, by calcination at 500 °C and a reduction in H2 at 300 °C. The catalyst obtained via hydrothermal synthesis showed a three-fold higher specific surface area with a four-fold higher active phase dispersion compared to the catalysts synthesized via conventional impregnation. The catalysts were tested in stearic acid deoxygenation in supercritical n-hexane as the solvent. Under optimized process conditions (temperature... [more]
Development and Characterization of a Novel Microwave Plasma Source for Enhanced Healing in Wound Treatment
Todor Bogdanov, Maria Simeonova, Lubomir Traikov, Todor Hikov, Andrey Petrov, Dimitar Peychinov, Dimitar Bakalov, Zafer Sabit, Radka Tafradjiiska-Hadjiolova, Rene Mileva
August 23, 2024 (v1)
Subject: Biosystems
Keywords: argon plasma, cold atmospheric plasma, microwave plasma, microwave plasma, plasma device, tissue regeneration, wound care, wound healing, wound regeneration
Our study explores the potential of a novel microwave plasma source for enhancing wound healing in BALB-C mouse models. Chronic wounds, particularly in diabetic individuals, present significant challenges due to impaired regenerative capacity. Cold Atmospheric Plasma (CAP) has emerged as a promising approach, offering diverse therapeutic benefits. However, its specific efficacy in the context of diabetic wounds remains underexplored. We developed and characterized a microwave plasma source optimized for wound treatment, inducing acute wounds and treating them with CAP in a controlled experimental setup. The treated group exhibited accelerated wound closure compared to controls, suggesting CAP’s potential to enhance the healing process. Our findings underscore CAP’s multifaceted impact on the wound healing cascade, highlighting its ability to promote angiogenesis, modulate inflammatory responses, and exhibit antimicrobial properties. These results position CAP as a promising interventio... [more]
Application of Principal Component Analysis for the Elucidation of Operational Features for Pervaporation Desalination Performance of PVA-Based TFC Membrane
Hamdi Chaouk, Emil Obeid, Jalal Halwani, Jack Arayro, Rabih Mezher, Semaan Amine, Eddie Gazo Hanna, Omar Mouhtady, Khaled Younes
August 23, 2024 (v1)
Keywords: operational features, pervaporation desalination, principal component analysis, PVA-based TFC membrane
Principal Component Analysis (PCA) serves as a valuable tool for analyzing membrane processes, offering insights into complex datasets, identifying crucial factors influencing membrane performance, aiding in design and optimization, and facilitating monitoring and fault diagnosis. In this study, PCA is applied to understand operational features affecting pervaporation desalination performance of PVA-based TFC membranes. PCA-biplot representation reveals that the first two principal components (PCs) accounted for 62.34% of the total variance, with normalized permeation with selective layer thickness (Pnorm), water permeation flux (P), and operational temperature (T) contributing significantly to PC1, while salt rejection dominates PC2. Membrane clustering indicates distinct influences, with membranes grouped based on correlation with operational factors. Excluding outliers increases total variance to 74.15%, showing altered membrane arrangements. Interestingly, the adopted strategy show... [more]
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