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Showing records 38 to 62 of 263. [First] Page: 1 2 3 4 5 6 7 Last
Advancing Fault Prediction: A Comparative Study between LSTM and Spiking Neural Networks
Rute Souza de Abreu, Ivanovitch Silva, Yuri Thomas Nunes, Renan C. Moioli, Luiz Affonso Guedes
February 10, 2024 (v1)
Keywords: generalized stochastic Petri net (GSPN), industrial processes, LSTM networks, spiking neural networks (SNNs), system fault prediction
Predicting system faults is critical to improving productivity, reducing costs, and enforcing safety in industrial processes. Yet, traditional methodologies frequently falter due to the intricate nature of the task. This research presents a novel use of spiking neural networks (SNNs) in anticipating faults in syntactical time series, utilizing the generalized stochastic Petri net (GSPN) model. The inherent ability of SNNs to process both time and space aspects of data positions them as a prime instrument for this endeavor. A comparative evaluation with long short-term memory (LSTM) networks suggests that SNNs offer comparable robustness and performance.
Effect of Hot Filament Chemical Vapor Deposition Filament Distribution on Coated Tools Performance in Milling of Zirconia Ceramics
Louis Luo Fan, Wai Sze Yip, Zhanwan Sun, Baolong Zhang, Suet To
February 10, 2024 (v1)
Subject: Materials
Keywords: diamond-coated tools, hot filament chemical vapor deposition, micro-milling, surface integrity, zirconia
Zirconia ceramics (ZrO2) have been used for a variety of applications due to their superior physical properties, including in machining tools and dentures. Nonetheless, due to its extreme hardness and brittleness in both sintered and half-sintered forms, zirconia is difficult to machine. In this study, half-sintered zirconia blocks are milled with tungsten carbide milling tools which arecoated with diamond film using hot filament chemical vapor deposition (HFCVD) at various substrate-to-filament distances. The objective was to determine the effect of substrate-to-filament distances on the coating thickness, diamond purity, coating grain size, and ZrO2 machining performance during HFCVD. The experimental results show that, in HFCVD, the grain size and coating thickness of the diamond film on milling tools tend to decrease when the substrate-to-filament distances decrease. Tool failure happened at a cutting time of 200 min for all coated tools. However, the machining quality in terms of... [more]
A Review of Nano and Microscale Heat Transfer: An Experimental and Molecular Dynamics Perspective
Samyabrata Chatterjee, Paras, Han Hu, Monojit Chakraborty
February 10, 2024 (v1)
Keywords: force-fields, liquid thin-film, microelectronic devices, molecular dynamics, thermal transportation
Significant progress in the development of micro and nanoscale devices has been observed for the past three decades. The thermal transportation in these small-length scales varies significantly, and it is difficult to explain the underlying physics using the pre-existing theoretical formulations. When the bulk dimension of a system is comparable to or smaller than the mean free path (MFP) of the thermal carriers, classical theories, such as Fourier’s Law of heat conduction, are unable to accurately explain the system energy dynamics. The phenomena of energy transit and conversion at the micro to nanoscale is an interesting topic of research due to the substantial changes in behavior that are documented when compared to those at the macro size. This review article is broadly divided into two parts. Initially, the recent development in the field of molecular dynamic (MD) simulations is emphasized. Classical MD simulation is such a powerful tool that provides insight into the length scale... [more]
Polyphenols as Antioxidant/Pro-Oxidant Compounds and Donors of Reducing Species: Relationship with Human Antioxidant Metabolism
Celia María Curieses Andrés, José Manuel Pérez de la Lastra, Celia Andrés Juan, Francisco J. Plou, Eduardo Pérez-Lebeña
February 10, 2024 (v1)
Keywords: antioxidant metabolism, antioxidant/pro-oxidant features, NRF2/ARE axis, polyphenols
In this review, we have focused mainly on the study of their antioxidant and pro-oxidant capacity, and the analysis of the oxidation of the catechol group to o-quinone. The redox balance established between the different oxidase and reductase enzymes generates reducing species, H+ and e−, and allows the oxidation of polyphenolic groups to quinones to be reversible. This continuous balance between these nucleophilic and electrophilic substances allows the activation of the NRF2/ARE axis, which regulates cellular antioxidant responses against oxidative stress, as well as cell proliferation. Understanding the ambivalent character of polyphenols, which can act simultaneously as antioxidants and pro-oxidants, will allow the design of specific therapies that can serve science and medicine in their tasks.
Novel Control Technology for Reducing Output Power Harmonics of Standalone Solar Power Generation Systems
Hwa-Dong Liu, Jhen-Ting Lin, Xin-Wen Lin, Chang-Hua Lin, Shoeb-Azam Farooqui
February 10, 2024 (v1)
Keywords: adjustable frequency and duty cycle, cake sweetness maximum power point tracking, standalone solar power system, total voltage harmonic distortion
This study presents a standalone solar power system that incorporates a photovoltaic (PV) module, a boost converter, an H-bridge inverter, a low-pass filter (LPF), and a microcontroller unit (MCU). A novel cake sweetness maximum power point tracking (CS MPPT) algorithm and adjustable frequency and duty cycle (AFDC) control strategy has been proposed and efficiently applied to the solar power system for optimizing the system efficiency and output power quality. The experimental results show that the proposed CS MPPT algorithm achieves an efficiency of 99% under both the uniform irradiance conditions (UIC) and partial shading conditions (PSC). Subsequently, the AFDC control strategy is applied to the H-bridge inverter which improves the output AC voltage and AC current and thereby improving the power quality. The system ensures a stable 110 Vrms/60 Hz AC output voltage with only 2% total voltage harmonic distortion of voltage (THDv), and produces a high-quality output voltage with reduce... [more]
Antibacterial Activities of Oral Care Products Containing Natural Plant Extracts from the Thai Highlands against Staphylococcus aureus: Evaluation and Satisfaction Studies
Saranya Chaiwaree, Kannika Srilai, Kantaporn Kheawfu, Patcharin Thammasit
February 10, 2024 (v1)
Subject: Biosystems
Keywords: antibacterial, highland areas, mouth spray, natural plant extracts, oral ulcer gel, satisfaction
In this research, we aimed to assess antibacterial activity and develop oral care products from three natural plant extracts from the Thai highlands. The plants, including Camellia sinensis var. assamica, Zanthozylum limonella Alston, and Acorus calamus L., were extracted using two traditional extraction techniques: maceration and hydrodistillation methods. The extracts were characterized by percentage yield, total phenolic, and total flavonoid contents. Antibacterial activity against Staphylococcus aureus, which play a role in oral health and disease, was investigated. C. sinensis var. assamica extract had the highest content of phenolic acid (38.15 ± 4.12 mg GAE/g extract) and flavonoids (44.91 ± 2.76 mg QE/g extract). Interestingly, a combination of C. sinensis with Z. limonella and A. calamus provides a greater inhibitory effect against S. aureus. Furthermore, oral care products were prepared as a natural product mixture in two preparations: (i) oral ulcers gel and (ii) oral spray.... [more]
Prediction of Lost Circulation in Southwest Chinese Oil Fields Applying Improved WOA-BiLSTM
Xianming Liu, Wen Jia, Zhilin Li, Chao Wang, Feng Guan, Kexu Chen, Lichun Jia
February 10, 2024 (v1)
Subject: Optimization
Keywords: Bidirectional Long Short Term Memory, correlation analysis, improved whale optimization algorithm, lost circulation prior to drilling, prediction model
Drilling hazards can be significantly decreased by anticipating potential mud loss and then putting the right well control measures in place. Therefore, it is critical to provide early estimates of mud loss. To solve this problem, an enhanced WOA (Whale Optimization Algorithm) and a BiLSTM (Bidirectional Long Short Term Memory) optimization based prediction model of lost circulation prior to drilling has been created. In order to minimize the noise in the historical comprehensive logging data, a wavelet filtering technique was first used. Then, according to the nonlinear Spearman rank correlation coefficient between mud loss and logging parameter values from large to small, seven characteristic parameters were preferred, and the sliding window was used to extract the relevant data. Secondly, the number of neurons in the first and second hidden layers, the maximum training time, and the initial learning rate of the BiLSTM model were optimized using the enhanced WOA method. The BiLSTM ne... [more]
Study on Variable Stress Corrosion Susceptibility of Four Typical High-Strength Sucker Rods in High-Salinity Well Fluids
Fenna Zhang, Jia Li, Hongying Zhu, Chuankai Jing, Bin Wang, Yaoguang Qi
February 10, 2024 (v1)
Subject: Materials
Keywords: high-salinity conditions, high-strength sucker rod, single-factor test, SSRT, stress corrosion cracking susceptibility
To study the corrosion characteristics of high-strength sucker rods in high-salinity well fluids under alternating stresses, a single-factor stress corrosion test was designed. The slow strain rate tensile test (SSRT) was carried out for four kinds of high-strength sucker rods under different Cl− and HCO3− concentrations and with different service strengths, and the variable stress corrosion cracking susceptibility was analyzed. The results show that the elongation loss and absorbed work loss of the H-grade ultra-high-strength 4330 sucker rod after stress corrosion are greater than those of both the high-strength 4142 sucker rod and the high-strength 20CrMoA sucker rod. The elongation and absorbed work loss of the 30CrMoA and 20CrMoA sucker rods are less affected by the changes in Cl− and HCO3−. With the increase in use strength, the elongation and absorbed work loss of the high-strength sucker rod increase. The change in the surface of the sucker rod during the corrosion process is in... [more]
Dynamic Modeling and Parameter Identification of Double Casing Joints for Aircraft Fuel Pipelines
Lingxiao Quan, Chen Fu, Renyi Yao, Changhong Guo
February 10, 2024 (v1)
Keywords: double casing joint, flow–solid coupling, free modal, parameters identification
Double casing joints are flexible pipe joints used for connecting aircraft fuel pipelines, which can compensate for the displacement and corner of the connected pipes and have complex mechanical characteristics. However, it is difficult to use sensors to directly measure the mechanical connection parameters of flexible joints. In this paper, we construct a coupling dynamics model and parameter identification of a double casing joint. Firstly, we analyze the structure and working principle of double-layer casing joints and establish the dynamics model of a single-layer flexible joint based on the transfer matrix method. Then, we deduce the coupling matrix of the inner and outer pipeline according to the deformation coordination conditions combined with matrix dimension extension. We establish the coupling dynamics model of flow−solid coupling of double casing joints. Furthermore, parameters such as equivalent stiffness and damping of each motion of the double casing joint in the casing... [more]
A Review of Macroscopic Modeling for Shale Gas Production: Gas Flow Mechanisms, Multiscale Transport, and Solution Techniques
Yuyang Liu, Xiaowei Zhang, Wei Zhang, Wei Guo, Lixia Kang, Dan Liu, Jinliang Gao, Rongze Yu, Yuping Sun
February 10, 2024 (v1)
Keywords: hydraulic fractures, macroscopic modeling, shale gas reservoir
The boost of shale gas production in the last decade has reformed worldwide energy structure. The macroscale modeling of shale gas production becomes particularly important as the economic development of such resources relies on the deployment of expensive hydraulic fracturing and the reasonable planning of well schedules. A flood of literature was therefore published focused on accurately and efficiently simulating the production performance of shale gas and better accounting for the various geological features or flow mechanisms that control shale gas transport. In this regard, this paper presents a holistic review of the macroscopic modeling of gas transport in shale. The review is carried out from three important points of view, which are the modeling of the gas flow mechanisms, the representation of multiscale transport, and solution techniques for the mathematical models. Firstly, the importance of gas storage and flow mechanisms in shale is discussed, and the various theoretical... [more]
Study on Mechanism and Regularity of Rock Breaking by Pulsed Water Injection with Particles
Tian Zhao, Qingxiang Wu, Haifeng Lv, Heng Song, Xinke Yang, Tiancheng Fang
February 10, 2024 (v1)
Subject: Environment
Keywords: hard formation, particles, pulse, rock breaking, rock drilling, water injection
In recent years, the drilling technology applied to deep and ultra-deep formations has developed rapidly, but the drilling speed for hard formations is low. Therefore, it is very important to study the drilling methods for deep and hard strata. Particle pulsed jet drilling is a new drilling method based on particle jet impact drilling technology and high-pressure pulsed water jet impact drilling technology. In this paper, the mathematical models of the shear layer amplification coefficient and wave velocity are established based on a similar network theory, and the motion equations of a single particle and particle swarm are established according to the motion of particles in a pulsed jet environment. Then, based on the self-designed particle jet impact rock-breaking experimental platform, the numerical simulation results are compared, analyzed, and verified. The results show that the rock-breaking efficiency increases with the increase in the average velocity of the particle pulsed je... [more]
Exploration of Pyrolysis Behaviors of Waste Plastics (Polypropylene Plastic/Polyethylene Plastic/Polystyrene Plastic): Macro-Thermal Kinetics and Micro-Pyrolysis Mechanism
Weiwei Xuan, Shiying Yan, Yanwu Dong
February 10, 2024 (v1)
Subject: Materials
Keywords: DFT, pyrolysis kinetics, ReaxFF-MD, TG–MS, waste plastics
Pyrolysis is a promising technology used to recycle both the energy and chemicals in plastics. Three types of plastics, polyethylene plastic (PE), polypropylene plastic (PP) and polystyrene plastic (PS) were investigated using thermogravimetry−mass spectrometry (TG−MS) and reactive force field molecular dynamics (ReaxFF-MD) simulation. The thermogravimetric analysis showed that all three plastics lost weight during the pyrolysis in one step. The thermal decomposition stability is PS < PP < PE. The activation energies and reaction mechanism function of the three plastics were determined by the Kissinger and CR methods. Meanwhile, the ReaxFF-MD combined with density functional theory (DFT) was used to calculate the kinetics, as well as explore the pyrolysis mechanism. The calculated kinetic results agree well with the experimental methods. The common pyrolysis reaction process follows the dissociation sequence of the polymer to polymeric monomer and, then, to the gas molecules. Bas... [more]
Pyrolysis Behavior and Kinetics of Typical Crop Straw in Henan Province at Different Heating Rates
Po Hu, Chenghao Hou, Xinyu Lan, Honghao Sheng
February 10, 2024 (v1)
Subject: Materials
Keywords: pyrolysis, straw, temperature rise rate
Straw, which is characterized by its low cost, large quantity, and rich supply of biomass energy, is often converted into energy that can be utilized in industrial production through pyrolysis technology. This paper examines the pyrolysis experiments of four kinds of straw (rice, wheat, peanut, and corn) from the Henan Province of China, conducted in an air environment with varying temperature-rise rates. Based on the experimental results, an analysis was conducted on the effect of the rate of temperature rise on the degree of straw pyrolysis and the pyrolysis characteristics of each type of straw. The activation energies of the pyrolysis reactions were calculated utilizing the Kissinger−Akahira−Sunose (KAS), Flynn−Wall−Ozawa (FWO), and Starink methods. It was concluded that the pyrolysis process of all four types of straw could roughly be classified into three stages: dehydration and drying stage, volatile release stage, and carbonization stage. Among the four types of straw evaluated... [more]
Mechanisms of Stress Sensitivity on Artificial Fracture Conductivity in the Flowback Stage of Shale Gas Wells
Xuefeng Yang, Tianpeng Wu, Liming Ren, Shan Huang, Songxia Wang, Jiajun Li, Jiawei Liu, Jian Zhang, Feng Chen, Hao Chen
February 10, 2024 (v1)
Keywords: artificial fracture, flowback system, fracture conductivity, shale gas, stress sensitivity
The presence of a reasonable flowback system after fracturing is a necessary condition for the high production of shale gas wells. At present, the optimization of the flowback system lacks a relevant theoretical basis. Due to this lack, this study established a new method for evaluating the conductivity of artificial fractures in shale, which can quantitatively characterize the backflow, embedment, and fragmentation of proppant during the flowback process. Then, the mechanism of the stress sensitivity of artificial fractures on fracture conductivity during the flowback stage of the shale gas well was revealed by performing the artificial fracture conductivity evaluation experiment. The results show that a large amount of proppant migrates, and the fracture conductivity decreases rapidly in the early stage of flowback, and then the decline gradually slows down. When the effective stress is low, the proppant is mainly plastically deformed, and the degree of fragmentation and embedment is... [more]
Fouling Mitigation in Membrane Distillation Using Pulsation Flow Technique
Hani Abulkhair, Iqbal Ahmed Moujdin, Bashar Kaddoura, Muhammad Saad Khan
February 10, 2024 (v1)
Subject: Environment
Keywords: fouling, membrane distillation, mitigation, pulsation flow, wastewater treatment
The main obstacles to scaling up membrane distillation (MD) on a commercial level are membrane fouling and temperature polarization. Therefore, in this study, the significance of the pulsation feed flow phenomenon was used for membrane distillation (DCMD) polarization, and comparisons were made using steady-state feed flow. Two different Hertz and amplitudes of pulsation feed flow trends were used in DCMD using different sources of water, including distilled water, seawater, and wastewater. Compared to steady-state feed flow, the results revealed that flux was enhanced for seawater once the operating flow became turbulent, and it enhanced even more once the flow rate was increased and the turbulence flow was moved. For wastewater, pulsation in the feed flow had an impact on delaying the beginning of the flux decline point and enhancing the overall freshwater recovery. In both pulsation feed flows (1 and 2 Hertz), the results also revealed a deficiency in fouling and an improvement in t... [more]
Study on SiO2 Nanofluid Alternating CO2 Enhanced Oil Recovery in Low-Permeability Sandstone Reservoirs
Jiani Hu, Meilong Fu, Minxuan Li, Honglin He, Baofeng Hou, Lifeng Chen, Wenbo Liu
February 10, 2024 (v1)
Subject: Materials
Keywords: microcharacterization, oil flooding experiment, SiO2 nanofluid alternating CO2
Water alternating gas (WAG) flooding is a widely employed enhanced oil recovery method in various reservoirs worldwide. In this research, we will employ SiO2 nanofluid alternating with the CO2 injection method as a replacement for the conventional WAG process in oil flooding experiments. The conventional WAG method suffers from limitations in certain industrial applications, such as extended cycle times, susceptibility to water condensation and agglomeration, and ineffectiveness in low-permeability oil reservoirs, thus impeding the oil recovery factor. In order to solve these problems, this study introduces SiO2 nanofluid as a substitute medium and proposes a SiO2 nanofluid alternate CO2 flooding method to enhance oil recovery. Through the microcharacterization of SiO2 nanofluids, comprehensive evaluations of particle size, dispersibility, and emulsification performance were conducted. The experimental results revealed that both SiO2-I and SiO2-II nanoparticles exhibited uniform spheri... [more]
Effect of the Encapsulation Process on the Viability of Probiotics in a Simulated Gastrointestinal Tract Model Medium
Madina Jumazhanova, Zhaynagul Kakimova, Yerlan Zharykbasov, Samat Kassymov, Gulmira Zhumadilova, Alibek Muratbayev, Marzhan Tashybayeva, Anuarbek Suychinov
February 10, 2024 (v1)
Keywords: alginate, capsule, encapsulation, gelatine, probiotics, viability
The primary objective of this study was to investigate the survival rate of three species of encapsulated bacteria (Propionibacterium acidipropionicici, Propionibacterium freudenreichii, and Propionibacterium thoenii) in model solutions designed to simulate the acidity levels found within the human gastrointestinal tract. The capsules were prepared by extrusion from gelatin and sodium alginate in a 1:1 ratio on a laboratory encapsulator. The use of gelatin and sodium alginate was found to provide optimum characteristics suitable for encapsulation of live bacteria. Three strains of Propionibacterium asidirgorionici, Propionibacterium freudenreichii, and Propionibacterium thoenii were subjected to in vitro assay to evaluate their probiotic potential. The final cell survival rate of P. freudenreichii was 105 CFU/mL, indicating that this probiotic is sensitive to acidic medium. The viability of encapsulated probiotics was studied in a model medium simulating the gastrointestinal tract. It... [more]
Leaf Extract Inhibits Lipopolysaccharide-Induced Inflammatory Response in BV-2 Microglia Cells
Ji-Woong Park, Woong Kim, Chul Yung Choi, Seok-Jun Kim
February 10, 2024 (v1)
Subject: Biosystems
Keywords: cytokine, MAPK/NF-κB pathway, microglia, neuroinflammation, Rumex crispus
Background: Microglial cells are immune cells that operate within the central nervous system. Abnormally activated microglia cause neuroinflammation, which is linked with neurodegenerative disease. Previous research has revealed that Rumex crispus root extract exerts anti-inflammatory effects. However, it is not known whether Rumex crispus leaf extract (RLE) has anti-inflammatory effects on murine microglial cells, such as BV-2 cells. This study proposed to investigate the impact of RLE on inducing inflammation by LPS in BV-2 cells. Methods: LPS was used to induce inflammation in BV-2 cells, and then cell survival, changes in the levels of inflammation-related factors and pro-inflammatory cytokines, and NF-κB and MAPKs signaling pathway activity were evaluated in the presence or absence of RLE. Results: RLE treatment resulted in a reduction in nitric oxide (NO) production triggered by LPS without causing cytotoxic effects. In addition, both protein and mRNA expression levels of iNOS an... [more]
Comparison of Engine Emission Characteristics of Biodiesel from High-Acid Oil and Used Cooking Oil through Supercritical Methanol and Alkaline-Catalyst Transesterifications
Cherng-Yuan Lin, Yi-Wei Lin, Hsuan Yang
February 10, 2024 (v1)
Keywords: direct-injection diesel engine, engine emission, fatty acid methyl ester, soybean soapstock, supercritical methanol transesterification
The global trend towards net-zero carbon emissions from burning fuels in combustion engines alerts us to the alternative role of biodiesel. The manufacturing cost of biodiesel hinders the fast development of various types of biofuels. Feedstock cost is one of the major determining factors of biodiesel cost and thus the extent of its competitiveness in the fuel market with other available alternative fuels or fossil fuels. Some low-cost feedstocks such as high-acid oil, which is produced from the acidifying processes of soybean soapstock, frequently contain high contents of free fatty acids (FFAs) and water. Hence, those feedstocks cannot be used to produce biodiesel through strong alkaline catalyst transesterification on an industrial scale. In contrast, the water can be converted to hydroxyl radicals to enhance the formation of esters from the dissociation of the FFA in a supercritical reacting tank. Hence, cheap high-acid oils containing high amounts of water and FFAs were used to pr... [more]
Treatment Wetland with Thalia geniculata for Wastewater Depuration in the Department of Sucre, Colombia
Vicente Vergara-Flórez, Jorge Mieles-Galindo, Graciela Nani, Mayerlin Sandoval-Herazo, Luis Carlos Sandoval Herazo
February 10, 2024 (v1)
Subject: Environment
Keywords: hydraulic retention time, macrophytes, removal efficiency, sewage water, treatment wetland
Municipal and industrial wastewater discharge is a longstanding environmental problem that pollutes water bodies, affecting both the landscape and human health. In the department of Sucre, Colombia, nearby urban sewage is discharged into the Arroyo Grande de la Sabana, and only Sincelejo city has a treatment system in place. Therefore, it is critical to identify effective treatment methods for removing contaminants from water. The objective of this study was to evaluate the efficiency of a constructed wetland (CW) with horizontal subsurface flow (HSSF) planted with Thalia geniculata for treating wastewater from the Arroyo Grande de la Sabana in Sucre, Colombia. The study investigated the effectiveness of a constructed wetland planted with Thalia geniculata for treating wastewater from the Arroyo Grande de la Sabana in Sucre, Colombia. Two different hydraulic retention times (HRTs) of 3 and 5 days were tested, and the plant population density was analyzed to determine the better adaptat... [more]
Water-Energy-Environment Nexus Analysis Tools: Case Study for Canary Islands
David Borge-Diez, Francisco José García-Moya, Enrique Rosales-Asensio
February 10, 2024 (v1)
Subject: Environment
Keywords: analysis tool, greenhouse gases, Renewable and Sustainable Energy, sustainable development goals, Water-Energy-Environment nexus
Despite that previous research exists, there is a need for further research on the quantitative aspects of this Nexus. Existing Water-Energy-Environment Nexus management tools and frameworks are based on indicators aiming to model the whole system, analyze the involved resources, and test potential management strategies. The environmental, social, and economic consequences of actions already taken and ongoing projects require important focus because of the strong relationship between water and energy supply, and that both are key issues for society’s development and sustainability. The present research focuses on the indicators that the Water-Energy-Environment Nexus tools and frameworks use to analyze the whole problem. Existing tools often require large amounts of data, becoming a time-consuming process that lowers the capacity to evaluate the political problems of high pollutants. With the aim of accelerating time evaluation, this research builds an indicator to rapidly evaluate the... [more]
Iron and Hydrogen Peroxidation-Induced Post-Treatment Improvement of Municipal Mesophilic Digestate in an Alkaline Environment and Its Impact on Biosolids Quality
Umme Sharmeen Hyder, Ahmed AlSayed, Elsayed Elbeshbishy, Joseph McPhee, Reshmi Misir
February 10, 2024 (v1)
Subject: Environment
Keywords: biosolids post-treatment, biosolids quality analysis, centrate phosphorous removal, ferric chloride, hydrogen peroxide, mesophilic digestate
Challenges associated with mesophilic digestate (MD) involve volume, odor, and pathogens, which effective post-digestion treatments can address. The efficiency of MD post-treatment can be enhanced by conditioning with ferric chloride (FeCl3), hydrogen peroxide (H2O2), and polymer. This study aimed to observe the effect of combined chemical conditioning on volume reduction, phosphorus (P) release, odor, and pathogen reduction potential for MD. MD was conditioned with polymer only, polymer and FeCl3 at pH adjusted to 8.0 with lime (Ca(OH)2), and a blend of polymer, FeCl3, and hydrogen peroxide (H2O2) at pH 8.0. The results show that adding all three chemicals improved post-treatment efficiency at 2.1 kg/t DS FeCl3, 2.1 kg/t DS polymer, and 600 mg/L H2O2 at pH 8.0, compared with polymer or dual conditioning. At the combined dose, cake solid content, centrate P removal, and odor reduction capability improved compared with raw MD by 20%, 99%, and 66%, respectively. Combined chemical treatme... [more]
Design and Implementation of Defect Detection System Based on YOLOv5-CBAM for Lead Tabs in Secondary Battery Manufacturing
Jisang Mun, Jinyoub Kim, Yeji Do, Hayul Kim, Chegyu Lee, Jongpil Jeong
February 10, 2024 (v1)
Keywords: automatic defect detection, CBAM, computer vision, deep learning, lead tap, object detection, YOLOv5
According to QYResearch, a global market research firm, the global market size of secondary batteries is growing at an average annual rate of 8.1%, but fires and casualties continue to occur due to the lack of quality and reliability of secondary batteries. Therefore, improving the quality of secondary batteries is a major factor in determining a company’s competitive advantage. In particular, lead taps, which electrically connect the negative and positive electrodes of secondary batteries, are a key factor in determining the stability of the battery. Currently, the quality inspection of secondary battery lead tab manufacturers mostly consists of visual inspection after vision inspection with a rule-based algorithm, which has limitations on the types of defects that can be detected, and the inspection time is increasing due to overlapping inspections, which is directly related to productivity. Therefore, this study aims to automate the quality inspection of lead tabs of secondary batte... [more]
Investigating the Microwave-Assisted Extraction Conditions and Antioxidative and Anti-Inflammatory Capacities of Symphytum officinale WL Leaves
Kuo-Hao Lou, Ming-Shiun Tsai, Jane-Yii Wu
February 10, 2024 (v1)
Keywords: anti-inflammation, antioxidant, comfrey leaf extract, MAPK signaling, microwave-assisted extraction, NF-κB signaling, rosmarinic acid
(comfrey) is a perennial herb native to West Asia and Europe. Its root extracts are commonly used as a natural remedy to treat muscle, joint, skin, and bone disorders, especially in Europe. However, more information is needed on the biomedical functions of comfrey leaves. This study’s sequencing results of internal transcribed spacer and trnL−trnF genes showed that plants purchased from the local market were comfrey and named S. officinale WL (WL). The suitable extraction conditions of the WL leaves with the highest extract yield and total phenols and flavonoid contents by microwave-assisted extraction were identified. The antioxidative and anti-inflammatory activities and possible molecular mechanism(s) of the WL leaf extract (WLE) were evaluated. Furthermore, the major component of WLE was identified as rosmarinic acid by HPLC. Results showed that the optimal extract condition was obtained with 750 W microwave power, 50 °C, 75% methanol, the solid-to-solvent ratio of 1:10, and 15 min... [more]
Evaluation of Supramolecular Gel Properties and Its Application in Drilling Fluid Plugging
Xiaoyong Du, Shaobo Feng, Haiying Lu, Yingrui Bai, Zhiqiang Lv
February 10, 2024 (v1)
Subject: Materials
Keywords: drilling fluid plugging, non-covalent effect, plugging performance, rheological mechanical properties, supramolecular gel
Supramolecular gels are physically cross-linked hydrogels formed by non-covalent interactions. The synthesis, structure optimization, property regulation, and application expansion of supramolecular gels has gradually become the research hotspot in the field of gel materials. According to the non-covalent interactions such as hydrophobic association and hydrogen bonding, the supramolecular gel prepared in this study has excellent rheological properties and adaptive filling and plugging properties, and can be used in the field of drilling fluid plugging. In this paper, the microstructure, rheological properties, temperature resistance, and plugging properties of supramolecular gels were studied and characterized in detail. The experimental findings demonstrated that when the strain was less than 10%, the supramolecular gel displayed an excellent linear viscoelastic region. The increase in strain weakens the rheological properties of supramolecular gel and reduces the elastic modulus of... [more]
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