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Showing records 670 to 694 of 43292. [First] Page: 1 24 25 26 27 28 29 30 31 32 Last
RETRACTED: Wong et al. In-Situ Yeast Fermentation Medium in Fortifying Protein and Lipid Accumulations in the Harvested Larval Biomass of Black Soldier Fly. Processes 2020, 8, 337
Chung Yiin Wong, Yeek Chia Ho, Jun Wei Lim, Pau Loke Show, Siewhui Chong, Yi Jing Chan, Chii Dong Ho, Mardawani Mohamad, Ta Yeong Wu, Man Kee Lam, Guan Ting Pan.
August 23, 2024 (v1)
Subject: Biosystems
The Processes Editorial Office retracts the article titled “RETRACTED: In-Situ Yeast Fermentation Medium in Fortifying Protein and Lipid Accumulations in the Harvested Larval Biomass of Black Soldier Fly” [...]
The Analysis of Transient Temperature in the Wellbore of a Deep Shale Gas Horizontal Well
Shilong Zhang, Jianhong Fu, Chi Peng, Yu Su, Honglin Zhang, Mou Yang.
August 23, 2024 (v1)
Keywords: deep shale gas, heat exchange, horizontal well, sensitivity analysis, wellbore temperature.
The transient temperature of the wellbore plays an important role in the selection of downhole tools during the drilling of deep shale gas horizontal wells. This study established a transient temperature field model of horizontal wells based on the convection heat transfer between wellbore and formation and the principle of energy conservation. The model verification shows that the root mean squared error (RMSE) between the measured annular temperature neat bit and the predicted value is 0.54 °C, indicating high accuracy. A well in Chongqing, China, is taken as an example to study the effects of bottom hole assembly (BHA), drill pipe size, drilling fluid density, flow rate, inlet temperature of drilling fluid, and drilling fluid circulation time on the temperature distribution in wellbore annulus. It is found that the increase in annular temperature is about 1 °C/100 m in the horizontal section when a positive displacement motor (PDM) is used. A Φ139.7 mm drill pipe is more favorable f... [more]
Tiny Particles, Big Problems: The Threat of Microplastics to Marine Life and Human Health
Goutam Saha, Suvash C. Saha.
August 23, 2024 (v1)
Subject: Environment
Keywords: fish species, human health, marine environment, microplastics, sources.
Microplastics, primarily derived from plastic waste, are pervasive environmental pollutants found across aquatic and terrestrial ecosystems. This review investigates microplastics’ presence, distribution, and impacts in marine ecosystems, with a particular focus on fish species. Research indicates that microplastics are present in various anatomical parts of fish, including the gastrointestinal tracts and gills, with significant implications for marine biodiversity and human health through seafood consumption. The review also highlights the sources of microplastics, such as synthetic textiles, packaging, and personal care products, and explores the pathways through which these particles enter marine environments. Advanced detection techniques have identified microplastics in human tissues, underscoring the urgency of addressing this environmental threat. Comprehensive strategies are essential to mitigate microplastic pollution and protect both marine life and human health.
Mitigation of Sugar Industry Wastewater Pollution: Efficiency of Lab-Scale Horizontal Subsurface Flow Wetlands
Talmeez Ur Rehman, Hassan Waseem, Babar Ali, Abdul Haleem, Rameesha Abid, Safia Ahmed, Kimberley A. Gilbride, Mahwish Ali.
August 23, 2024 (v1)
Subject: Environment
Keywords: constructed wetlands, degradation, microbes, sugar industry, toxicity.
Sugarcane accounts for around 80% of global sugar production. However, the sugar industry is known for producing significant amounts of organic wastewater with a high COD (5000−8000 mg/L) that severely pollutes the environment. A lab-scale trial was conducted to evaluate the efficacy of a horizontal subsurface flow wetland planted with Typha latifolia and Phragmites australis in removing pollutants from sugar industry wastewater. The wetland system was subjected to rigorous testing, operating at a high flow rate of 2.166 gallons per day and exposed to a high organic loading rate (3800 mg/L COD and 2470 mg/L BOD), as well as elevated levels of inorganic nitrogen, sulfate, and phosphate (100 mg/L, 80 mg/L, and 10 mg/L, respectively). Our findings indicate significant removal efficiencies, with the wetland system achieving removal rates of 88% for COD, 97% for BOD, 96% for total nitrogen, and 95% for sulfate. Remarkably, the system exhibited enhanced removal efficiency when exposed to dom... [more]
Geochemical Characteristics and Hydrocarbon Generation Potential of Coal-Measure Source Rocks in Julu Sag
Yang Wang, Hanyu Zhang, Liu Yang, Yanming Zhu, Zhixiang Chang.
August 23, 2024 (v1)
Subject: Other
Keywords: coal-measure gas, hydrocarbon generation evolution, Julu sag, source rock, tectonic evolution.
To uncover the reservoir characteristics and enrichment law of coal-measure gas in Julu sag, Hebei Province, and achieve co-exploration and co-mining, it is necessary to conduct a comprehensive analysis. In this study, we investigated the characteristics of coal-measure gas accumulation in the Taiyuan Formation and Shanxi Formation in the Julu area. This was achieved by collecting data on coal-measure source rocks and organic geochemistry, which were then combined with regional geological conditions. This study indicates that the coal seams and shales of Shanxi Formation and Taiyuan Formation in the study area serve as the primary source rocks. The predominant macerals found in coal rock are vitrinite. Furthermore, the organic matter type present in shale is primarily categorized as type II2, with the organic matter maturity falling within the immature−mature stage. Based on the simulation results of tectonic-burial history, thermal evolution history, and hydrocarbon generation history... [more]
Failure Characteristics and Cooperative Control Strategies for Gob-Side Entry Driving near an Advancing Working Face: A Case Study
Wenda Wu, Tianchen Wang, Jianbiao Bai, Jinhu Liu, Xiangyu Wang, Haiyun Xu, Guorui Feng.
August 23, 2024 (v1)
Keywords: coal pillar width, cooperative control strategies, double-yield model, gob-side entry driving near an advancing working face, stability of surrounding rock.
Gob-side entry driving near an advancing working face can improve the recovery rate of coal resources and keep the balance between mining and development. However, the large displacement of the gob-side entry caused by the mining dynamics of abutment pressure challenges the safety and processes of coal mining. This article takes the 15102 tailentry of Xizhang Coal Mine in Changzhi City, Shanxi Province, as an example to study the stability of the coal pillar and the failure characteristics of the surrounding rock and proposes cooperative control strategies of surrounding rock stability. Field tests indicated that when the coal pillar width was 15 m, the displacements of the entry floor, roof, coal pillar side, and solid coal side were 1121 mm, 601 mm, 783 mm, and 237 mm, respectively. A meticulously validated numerical model, incorporating a double-yield model for the gob materials and calibrated parameters, was developed to investigate the stress changes and yield zone distribution ac... [more]
Information Gap Decision Theory-Based Robust Economic Dispatch Strategy Considering the Uncertainty of Electric Vehicles
Yongqing Guo, Junhui Yu, Yan Yang, Hengrui Ma.
August 23, 2024 (v1)
Keywords: decision conservatism, electric vehicles (EVs), information gap decision theory (IGDT), Monte Carlo method, power system.
With the development of renewable energy power systems, electric vehicles, as an important carrier of green transportation, are gradually having an impact on the power grid load curve due to their charging behavior. However, the significant influx of electric vehicles (EVs) and distributed power sources has led to multiple uncertainties, increasing the difficulty in making grid scheduling decisions. Traditional robust scheduling strategies tend to be overly conservative, resulting in poor economic performance. Therefore, this paper proposes a robust and economic dispatch strategy for park power grids based on the information gap decision theory (IGDT). Firstly, based on the probabilistic characteristics of the spatial and temporal distribution of EVs charging, the Monte Carlo method is used to generate typical electricity usage scenarios for EVs. Simultaneously, an economic dispatch model for the park power grid is established with the objective of minimizing operating costs. Taking in... [more]
Research on the Supercritical CO2 Extraction Process of Hetian Rose Essential Oil
Wei Cui, Rongji Xu, Xiaoqiong Li, Junling Yang, Peng Xu, Zhentao Zhang, Ze Yu, Saramaiti Adiges.
August 23, 2024 (v1)
Subject: Materials
Keywords: extraction influencing factors, extraction pressure, extraction temperature, preprocessing method, rose essential oils, supercritical CO2 extraction.
A longstanding concern in plant essential oil extraction is how to optimize extraction efficiency with limited materials. Supercritical CO2 extraction has been proven effective in enhancing the yield and efficiency of extracting plant essential oils. However, the impact of temperature, pressure, and co-solvent content on extracting Hetian rose essential oil remains unclear. There is a lack of research on the influence of pretreatment methods. This study focuses on investigating supercritical CO2 extraction of rose essential oils from Xinjiang Hetian. The research analyzes the effects of pressure and temperature on the extraction rate and validates the efficiency by calculating the solubility of essential oils in supercritical fluid. Under conditions of 35 MPa, 40 °C, 10 L/h, and a particle size of 0.8 mm, this study evaluates the extraction efficiency using Xinjiang Hetian rose materials pretreated with salt solutions at concentrations of 5%, 10%, and 20%, as well as enzyme solutions a... [more]
Efficient Identification Method for Power Quality Disturbance: A Hybrid Data-Driven Strategy
Qunwei Xu, Feibai Zhu, Wendong Jiang, Xing Pan, Pei Li, Xiang Zhou, Yang Wang.
August 23, 2024 (v1)
Keywords: disturbance identification, extreme learning machine (ELM), local mean decomposition (LMD) algorithm, power quality, wavelet packet transform (WPT) method.
The massive integration of distributed renewable energy sources and nonlinear power electronic equipment has given rise to power quality issues such as waveform distortion, voltage instability, and increased harmonic components. Nowadays, the pollution of power quality is becoming increasingly severe, posing a potential threat to the security of the power grid and the stable operation of electrical equipment. Due to the presence of significant noise interference in the collected signals, existing methods still face issues such as low accuracy in disturbance identification and high computational complexity. To address these problems, this paper proposes a hybrid data-driven strategy that can significantly improve the accuracy and speed of identification. Firstly, the wavelet packet transform (WPT) method is employed to denoise the power disturbance signals. Subsequently, the local mean decomposition (LMD) algorithm is used to adaptively decompose the nonlinear and complex time series in... [more]
Numerical Simulation of Rock Vibration Response under Ultrasonic High-Frequency Vibration with High Confining Pressure
Minsheng Wang, Lingchao Xuan, Weikai Liu, Jinyu Feng, Heng Wang.
August 23, 2024 (v1)
Keywords: high-frequency vibration, rock crushing, rock response.
As deep oil and gas resources and Carbon Capture and Storage (CCS) are developed, enhancing drilling efficiency in hard rock formations has emerged as a critical technology in oil and gas extraction. The advancement of ultrasonic, high-frequency vibration rock-breaking technology significantly facilitates efficient rock crushing. When subjected to ultrasonic high-frequency vibrations, the rock’s response is a crucial issue in implementing ultrasonic vibration rock crushing technology. This study employed numerical simulation and theoretical deduction methods, utilizing a multi-physics approach that couples solid mechanics with pressure acoustics. It integrated information on common influencing parameters of ultrasonic generators and reservoir rock properties to establish model parameters, analyze simulation results, and perform theoretical deductions. The research investigated the response patterns of different-sized rock samples under high-frequency ultrasound vibration excitation acr... [more]
Design and Analysis of Manufacturing Methods for Tiller Blades and Threshing Teeth in Bangladesh
Laura Rundquist, Jonathan Colton.
August 23, 2024 (v1)
Keywords: agriculture, bending, forging, manufacturing, mechanization.
Bangladesh is increasing agricultural mechanization to reduce labor-intensive drudgery and to address labor shortages in farming. Agricultural equipment, such as power tillers and threshers, are used to achieve this goal and require regular replacement of the spare parts that experience significant wear in use. Spare parts are currently imported at twice the cost of domestic ones. This paper supports the development of domestic manufacturing by analyzing the manufacturing processes for two fast-moving spare agricultural parts, tiller blades and threshing teeth, and providing a method to develop more efficient processes. The manufacturing processes, which focused on the design of forging and bending dies, reflect the constraints of the manufacturing equipment and stock materials available in Bangladesh. The die designs and manufacturing processes were verified by FEA simulations and by experimental testing. The experiments and simulations suggest that the spare parts should be made at e... [more]
Optimization of Fine-Fracture Distribution Patterns for Multi-Stage and Multi-Cluster Fractured Horizontal Wells in Tight Gas Reservoirs
Long Ren, Junzhang Wang, Cong Zhao, Cheng Jing, Jian Sun, Desheng Zhou, Fuguo Xiang, Diguang Gong, Haiyan Li.
August 23, 2024 (v1)
Keywords: fracture distribution pattern, horizontal well, multi-stage and multi-cluster fracturing, numerical simulation optimization, tight gas reservoirs.
The efficient development of tight gas reservoirs is significantly enhanced by multi-stage and multi-cluster fracturing techniques in conjunction with horizontal well technology, leading to substantial increases in reservoir drainage volume and individual well productivity. This study presents a tailored fine-fracturing approach for horizontal wells in tight gas reservoirs, supported by a gas−water two-phase numerical simulation model. Utilizing the orthogonal experimental design method, we simulated and optimized various fracture distribution schemes to refine fracturing parameters for maximum efficiency. The optimization was further validated through a comparison with actual well completion and development dynamics. The quantitative results highlight the optimal fracture distribution for horizontal wells, with a horizontal section length of 1400 to 1600 m and 14 to 16 fracturing stages. The pattern features a “dense at both ends and sparse in the middle” strategy, with stage spacing... [more]
Quality Evolution of Extra Virgin Olive Oils of ‘Chemlal’ Cultivar during Storage at Environment Temperature: Effect of the Altitude and Age of Olive Trees
Yamina Derdah, Mariam Hedjal, Natividad Ramos Martos, Karima Taleb Toudert, Sebastián Sánchez.
August 23, 2024 (v1)
Subject: Environment
Keywords: extra virgin olive oils, fatty acids, Kabylia, oxidative stability, phenolic compounds, storage, tocopherols.
This work aimed to study the influence of two factors on oil composition: the altitude of olive groves and the age of olive trees, as well as the duration olive oil was stored in the dark and at room temperature. Firstly, quality parameters (free acidity, peroxide value, K232 and K270), minor compounds (pigments, total phenolic compounds, tocopherol fraction and fatty acid profile) and oxidative stability measured at 98.0 °C (by Rancimat) made it possible to evaluate the quality of the samples during one year of storage. A significant difference was reported in pigment contents as a function of altitude. In particular, several changes were observed during storage, which led on the one hand to a continuous increase in free acidity, peroxide value, K232, K270 and on the other hand a degradation of natural antioxidants such as phenolic compounds, pigments and tocopherols and consequently to oxidation stability. However, the modification of the fatty acid composition was small and did not... [more]
Impact of Spray Drying on the Properties of Grape Pomace Extract Powder
Betina Louise Angioletti Decker, Emilio de Castro Miguel, Thatyane Vidal Fonteles, Fabiano A. N. Fernandes, Sueli Rodrigues.
August 23, 2024 (v1)
Subject: Biosystems
Keywords: anthocyanin stability, bioactive compounds, encapsulation, green solvents, maltodextrin, malvidin, powder cohesiveness.
Incorporating anthocyanins, valuable natural pigments, into a powder can improve their stability, but exposure to high temperatures during processing can cause them to degrade. The purpose of this study was to investigate how the inlet air temperature during spray drying affects the physical and chemical characteristics as well as the flowability of a grape pomace anthocyanin powder obtained through ultrasound-assisted extraction using acidified water as the solvent. An anthocyanin solution containing 13% (w/v) maltodextrin was subjected to spray drying at temperatures ranging from 120 to 170 °C. Tukey’s test was applied to compare the means of the samples. The samples dried at temperatures between 130 and 170 °C were adequate, with a moisture content < 5% and a water activity < 0.3, indicating that the powder was stable. The highest anthocyanin retention (91.94 ± 1.59%) and process yield (50.00 ± 3.06%) were achieved at 140 °C, while higher temperatures resulted in anthocyanin degr... [more]
Evaluation of Thermal Insulation of Vacuum-Insulated Casing to Prevent Uncontrollable Melting of Ice and Borehole Instability in Permafrost
Xiaohui Zhou, Yinao Su, Yuanfang Cheng, Qingchao Li.
August 23, 2024 (v1)
Subject: Other
Keywords: ice melting, oil and gas production, permafrost, thermal conductivity, vacuum-insulated casing, wellbore stability.
During oil and gas development in permafrost, hot fluids within the wellbore can cause ice melting around wellbore and a decrease in sediment strength, as well as wellbore instability. In the present work, the experimental system for evaluating the insulation effectiveness was established, and the applicability of this experimental system and methodology was verified. It was found that the difference between the experimentally obtained and actual thermal conductivity of the ordinary casings are all within 1.0 W/(m·°C). Meanwhile, the evaluation of insulation effect found that the decrease in fluid temperature, ambient temperature, and vacuum degree can improve its insulation performance. Finally, the numerical simulation was conducted on ice melting and borehole stability during the drilling operation in permafrost. The investigation results demonstrate that the use of vacuum-insulated casings significantly reduces the total heat transferred during the simulation by 86.72% compared to... [more]
Interpreting Digital Transformation from a Psychological Perspective: A Case Study of the Oil and Gas Industry
Jiaming Zhang, Yan Yang, Yundong Zhang, Shuaiqi Liu, Maoxin Qiu, Huazhen Zhang.
August 23, 2024 (v1)
Keywords: digital revolution, digitalization, Industry 4.0, Industry 5.0, psychology, transformation.
This article addresses the problem statement and objective by exploring the necessity, scope, and execution of digital transformation in the oil and gas industry from a psychological perspective. It highlights the cognitive barriers faced by non-ICT professionals, which are often overlooked in traditional approaches. The study integrates case studies and empirical evidence from a mixed-methods approach, including qualitative interviews with industry experts and quantitative surveys among employees, to provide a comprehensive understanding of the transformation process. The research emphasizes the integration of psychological theories with practical digital transformation strategies, illustrating key obstacles and solutions. By adopting a holistic approach that incorporates both technological advancements and psychological insights, the study aims to enhance the effectiveness and sustainability of digital transformation efforts. Major contributions include identifying cognitive barriers... [more]
High-Surface-Area Co-Cu-B Monolithic Self-Supported Catalyst for Efficient Sodium Borohydride Hydrolysis
Wuning Yuan, Xiao Yang, Cheng Liu, Liangyao Xue, Wenzhe Niu, Qisheng Yan, Yajie Zhu, Junchao Han, Wen Guo, Bo Zhang.
August 23, 2024 (v1)
Subject: Materials
Keywords: Catalysis, hydrogen generation, NaBH4 hydrolysis, PEMFC.
Sodium borohydride (NaBH4) is a nontoxic and ideal storage material for hydrogen due to its safety and high hydrogen storage capacity. In order to improve the practicality of the sodium borohydride hydrogen production system, we deposited non-precious metal catalytic materials on readily available polymer foams using a simple chemical plating method, developing a suitable 3D catalyst. Its high specific surface area enables it to produce hydrogen at a rate of up to 3.92 L min−1 g−1. Its unique structure gives the catalyst excellent durability. In addition, an efficient NaBH4-based H2 supply system was developed using this catalyst. Co-Cu-B can facilitate stable hydrogen production from NaBH4, yielding a consistent power output ranging from 0 to 100 W. This work provides a new pathway for developing high-efficiency monolithic self-supported catalysts for industrial applications.
Cold Atmospheric Plasma (CAP) Treatment of In Vitro Cultivated Plum Plantlets—A Possible Way to Improve Growth and Inactivate Plum Pox Virus (PPV)
Lilyana Nacheva, Snezhana Milusheva, Plamena Marinova, Nataliya Dimitrova, Evgenia Benova.
August 23, 2024 (v1)
Keywords: cold atmospheric plasma, micropropagation, microwave plasma torch, plasma agriculture, Sharka, underwater diaphragm discharge, virus eradication.
Plasma technology, relatively new in the fields of biomedicine, agriculture, and ecology, is the subject of intensive research as a prospective means of decontamination of various microorganisms (bacteria, viruses, and fungi). The objectives of the present study were to follow the effect of cold atmospheric plasma (CAP) treatment on in vitro grown plum plants (Prunus domestica L. ‘Kyustendilska sinya’ cv.) and the possibility of eradicating or inactivating plum pox virus (PPV) causing Sharka disease by CAP. The source tree is naturally co-infected by PPV (both M and D strains). In the experiments, two different plasma sources were used. First, a surface-wave-sustained Argon plasma torch and second, an underwater diaphragm discharge. For the treatments, nodal segments (10 mm in length) from in vitro cultured plum plants with or without one leaf were prepared. Apical shoots from treated plants (PPV-positive and negative clones as well non-treated controls) were cultivated in vitro for fo... [more]
Application of Anti-Solvent Crystallization for High-Purity Potash Production from K-Feldspar Leaching Solution
Sina Shakibania, Lena Sundqvist-Öqvist, Jan Rosenkranz, Yousef Ghorbani.
August 23, 2024 (v1)
Keywords: 2-propanol, acetone, anti-solvent crystallization, K-feldspar, muriate, potash.
Potassium-containing feldspars provide a high potential for producing potash, a product with widespread use in agriculture. The present work assesses applying the anti-solvent crystallization method for the purification and recovery of high-purity muriate of potash (KCl) from feldspar leaching solutions. Initially, screening experiments were carried out on a synthetic leaching solution with the aim of analyzing the crystallization behavior of key components. Screening experiments were performed using five anti-solvents, namely methanol, ethanol, acetone, 2-propanol, and ethylene glycol. Acetone and 2-propanol were viable options for crystallization of potassium chloride. Then, the effects of anti-solvent ratio (O/A), time, and anti-solvent addition rate on potassium-chloride crystallization were further investigated using acetone and 2-propanol. A recovery of 83% of potassium was achieved when using acetone at the O/A of 5 with the addition rate of 10 mL/min, at room temperature with a... [more]
Monitoring and Reconstruction of Actuator and Sensor Attacks for Lipschitz Nonlinear Dynamic Systems Using Two Types of Augmented Descriptor Observers
Hao Wang, Zhi-Wei Gao, Yuanhong Liu.
August 23, 2024 (v1)
Keywords: adaptive observer, attack monitoring, attack reconstruction, augmented descriptor system approach, data injection attack, sliding-mode observer.
Fault data injection attacks may lead to a decrease in system performance and even a malfunction in system operation for an automatic feedback control system, which has motive to develop an effective method for rapidly detecting such attacks so that appropriate measures can be taken correspondingly. In this study, a secure descriptor estimation technique is proposed for continuous-time Lipschitz nonlinear cyber physical systems affected by actuator attacks, sensor attacks, and unknown process uncertainties. Specifically, by forming a new state vector composed of original system states and sensor faults, an equivalent descriptor dynamic system is built. A proportional and derivate sliding-mode observer is presented so that the system states, sensor attack, and actuator attack can be reconstructed successfully. The observer gains are obtained by using linear matrix inequality to secure robustly stable estimation error dynamics. Moreover, a robust descriptor fast adaptive observer estimat... [more]
Research and Application of Treatment Measures for Low-Yield and Low-Efficiency Coalbed Methane Wells in Qinshui Basin
Lichun Sun, Zhigang Zhao, Chen Li, Ruyong Feng, Yanjun Meng, Yong Li.
August 23, 2024 (v1)
Keywords: coalbed methane, fracturing simulation, increase production, low-yield and low-efficiency well, production system optimization.
China is rich in high-grade coalbed methane resources, accounting for one-third of the total amount of coalbed methane resources. Qinshui Basin is the main high ranking coalbed methane mining basin in China. In the early stage of CBM development, low-production and low-efficiency wells were formed in the process of block development because of an insufficient understanding of reservoir geological conditions. The existence of low-yield and low-efficiency wells with low output and a poor development benefit seriously restricts the efficient development of coalbed methane. In order to improve the overall development efficiency of coalbed methane fields, how to revitalize low-yield and low-efficiency wells is the main problem facing the development process of coalbed methane. With the deepening understanding of the study area geology, the formation of low-yield and low-efficiency wells has been basically identified. With the advancement of development technology, developers have the abilit... [more]
Curvature-Adaptive Compact Triple-Band Metamaterial Uniplanar Compact Electromagnetic Bandgap-Based Printed Antenna for Wearable Wireless and Medical Body Area Network Applications
Tarek Messatfa, Souad Berhab, Fouad Chebbara, Mohamed S. Soliman.
August 23, 2024 (v1)
Subject: Materials
Keywords: 5G NR, apple-shaped wearable antenna, ISM, metamaterial, SAR, TCSRRs, triple-band, UC-EBG, WBAN/MBAN, WLAN.
A novel, compact, monopole apple-shaped, triple-band metamaterial-printed wearable antenna backed by a uniplanar compact electromagnetic bandgap (UC-EBG) structure is introduced in this paper for wearable wireless and medical body area network (WBAN/MBAN) applications. A tri-band UC-EBG structure has been utilized as a ground plane to minimize the impact of antenna radiation on the human body and improve antenna performance for the proposed wearable antenna. Metamaterial triangular complementary split ring resonators (TCSRRs) are incorporated into the antenna and UC-EBG structure, resulting in a compact UC-EBG-backed antenna with an overall size of 39 × 39 × 2.84 mm3 (0.41 λg × 0.41 λg × 0.029 λg). The printed textile antenna operates at 2.45 GHz for the wireless local area network (WLAN), 3.5 GHz for 5G new radio (NR), and 5.8 GHz for the industrial, scientific, and medical (ISM) bands with improved gain and high-efficiency values. Furthermore, the performance of the antenna is analyz... [more]
Editorial of the Topic “Environmental and Health Issues and Solutions for Anticoccidials and Other Emerging Pollutants of Special Concern”
Avelino Núñez-Delgado, Elza Bontempi, Yaoyu Zhou, Esperanza Álvarez-Rodríguez, María Victoria López-Ramón, Mario Coccia, Zhien Zhang, Vanesa Santás-Miguel, Marco Race.
August 23, 2024 (v1)
Subject: Environment
The editors of this Topic, entitled “Environmental and Health Issues and Solutions for Anticoccidials and other Emerging Pollutants of Special Concern”, proposed it with the knowledge that emerging pollutants continue to be of crucial importance [...]
A Semi-Global Finite-Time Dynamic Control Strategy of Stochastic Nonlinear Systems
Cuixian Luo, Lingrong Xue, Zhen-Guo Liu, Lifang Ren.
August 23, 2024 (v1)
Keywords: dynamic gain, homogeneous domination method, semi-global finite-time stable in probability, stochastic nonlinear system.
In the article, the semi-global finite-time control strategy for stochastic nonlinear systems is studied. Firstly, the general stochastic nonlinear system is considered and the required conditions are provided. An important theorem that helps to construct the controller directly is subsequently obtained by adopting a dynamic gain and homogeneous domination method. The equilibrium of the whole system is semi-global finite-time stable in probability (SGFSP) under the designed controller. Finally, the presented method is successfully applied to a second-order system. Simulation results indicate the effectiveness of the method.
Research on Multi-Objective Optimization of Low Pulsation Unloading Damping Groove of Axial Piston Pump
Dian He, Nan Xu, Haocen Hong, Bin Zhang, Shunhai Xu, Huayong Yang.
August 23, 2024 (v1)
Subject: Optimization
Keywords: axial piston pump, damping groove, flow rate, multi-objective optimization.
The high- and low-pressure switching of the axial piston pump is realized by the structure of the valve plate, and the buffer-groove structure on the valve plate is very important to reduce the pressure shock and flow fluctuation. In order to optimize the structural parameters of the buffer tank of the piston pump, the influence of the triangular-groove structure on the outlet pressure−flow characteristics was analyzed, and the low-pulsation buffer-groove structure was designed. First, the relationship between the structure of the triangular buffer tank and the output pressure and flow characteristics of the pump was analyzed theoretically. The Computational Fluid Dynamics (CFD) method was used to calculate the pressure and flow characteristics of the whole pump flow field of the triangular-groove structure, and the influence of the buffer-groove structure parameters on the outlet flow pulsation characteristics was studied. The multi-objective optimization algorithm was used to optimiz... [more]
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