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Showing records 37418 to 37442 of 43292. [First] Page: 1 1494 1495 1496 1497 1498 1499 1500 1501 1502 Last
37418. LAPSE:2023.1712
Performance of a Novel Enhanced Sparrow Search Algorithm for Engineering Design Process: Coverage Optimization in Wireless Sensor Network
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: coverage optimization, Modelling, Simulation, sparrow search algorithm, swarm intelligence, wireless sensor network
Burgeoning swarm intelligence techniques have been creating a feasible theoretical computational method for the modeling, simulation, and optimization of complex systems. This study aims to increase the coverage of a wireless sensor network (WSN) and puts forward an enhanced version of the sparrow search algorithm (SSA) as a processing tool to achieve this optimization. The enhancement of the algorithm covers three aspects. Firstly, the Latin hypercube sampling technique is utilized to generate the initial population to obtain a more uniform distribution in the search space. Secondly, a sine cosine algorithm with adaptive adjustment and the Lévy flight strategy are introduced as new optimization equations to enhance the convergence efficiency of the algorithm. Finally, to optimize the individuals with poor fitness in the population, a novel mutation disturbance mechanism is introduced at the end of each iteration. Through numerical tests of 13 benchmark functions, the experimental resu... [more]
37419. LAPSE:2023.1711
Screening and Testing of Anti-Slagging Agents for Tobacco-Stalk-Based Biomass Pellet Fuel for Tobacco Curing
February 21, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: anti-coking, circular agriculture, green energy, pellet fuel, tobacco curing, tobacco stalk
Using tobacco stalks as a biomass fuel for flue-cured tobacco production creates a closed, green production cycle. Tobacco stalks are rich in cellulose and can be crushed to produce biomass pellet fuel (BPF). However, single flue-cured tobacco stalk (FCTs) BPF can easily slag during flue-cured tobacco heating (FTH), which affects the operation of biomass burners. In this study, five anti-slagging agents (ASAs), one organic (sodium carboxymethyl cellulose, CMC) and four inorganic (kaolin, KLN; diatomite earth, DTE; calcium carbonate, CCO; and calcium dihydrogen phosphate, CHO)], were compared. An ash fusibility test was conducted in two steps to optimize the proportion and treatments that were then screened using FTH. Compared with pure FCT-based BPFs, the slag resistance of 2% CCO and CHO could be controlled below 15%. The emission of particulate matter from chimneys burning BPF with 2% CCO was lower than that with other ASAs. The ASAs achieved complete combustion with low carbon monox... [more]
37420. LAPSE:2023.1710
Flow Characteristics and Optimization Design of the Stator−Rotor Cavity of the Full Tubular Pump
February 21, 2023 (v1)
Subject: Process Design
Keywords: flow characteristics, full tubular pump, numerical simulation, optimization design, stator–rotor cavity
The full tubular pump device is taken as the research object in this article. This research method adopts the numerical simulation technology based on the SST (Shear-Stress-Transport) k-ω turbulence model to explore the internal flow characteristics of the stator−rotor cavity of the full tubular pump and optimize the stator−rotor clearance structure. The research shows that under the design conditions, compared with the axial flow pump, the torque increases by 47.91 N·m at the stator−rotor cavity structure and the efficiency decreases by about 20%. The torque at the rotor clearance of the full tubular pump accounts for about 50% of the torque at the rotor. Since there is a large area of backflow on both sides of the cavity, and there is a vortex structure on the inlet side of the cavity, it shows that the rotor structure and its area greatly affect the operating efficiency of the pump device. With the reduction in the rotor force area, the clearance length, and the outer diameter of th... [more]
37421. LAPSE:2023.1709
Performance, Combustion, and Emission Comparisons of a High-Speed Diesel Engine Fueled with Biodiesel with Different Ethanol Addition Ratios Based on a Combined Kinetic Mechanism
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: combustion, diesel engine, emissions, ethanol addition, performance
In this work, different ethanol ratios (5%, 10%, 15%, and 20%) blended with biodiesel were used to investigate the effects of ethanol addition on engine performance, combustion, and emission characteristics of a high-speed diesel engine in terms of brake power, brake specific fuel consumption, brake thermal efficiency, cylinder pressure, cylinder temperature, heat release rate, NOx, CO, and soot emissions. First, a three-dimensional CFD model was established by AVL-Fire combined with the CHEMKIN code. Then, an improved kinetic mechanism with 430 reactions and 122 species was developed by combining a three-component biodiesel combustion mechanism and ethanol mechanism to accurately simulate the blended fuel combustion processes. The results indicated that compared with biodiesel, the maximum brake specific fuel consumption increased by 6.08%, and the maximum brake thermal efficiency increased by 2.09% for the blended fuel. In addition, NOx and CO emissions for EE20 were reduced by 29.32... [more]
37422. LAPSE:2023.1708
Application of a Single Multilayer Perceptron Model to Predict the Solubility of CO2 in Different Ionic Liquids for Gas Removal Processes
February 21, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: algorithm learning, artificial neural network, Carbon Dioxide, ionic liquids, Levenberg–Marquard algorithm, multilayer perceptron, solubility
In this work, 2099 experimental data of binary systems composed of CO2 and ionic liquids are studied to predict solubility using a multilayer perceptron. The dataset includes 33 different types of ionic liquids over a wide range of temperatures, pressures, and solubilities. The main objective of this work is to propose a procedure for the prediction of CO2 solubility in ionic liquids by establishing four stages to determine the model parameters: (1) selection of the learning algorithm, (2) optimization of the first hidden layer, (3) optimization of the second hidden layer, and (4) selection of the input combination. In this study, a bound is set on the number of model parameters: the number of model parameters must be less than the amount of predicted data. Eight different learning algorithms with (4,m,n,1)-type hidden two-layer architectures (m = 2, 4, …, 10 and n = 2, 3, …, 10) are studied, and the artificial neural network is trained with three input combinations with three combinat... [more]
37423. LAPSE:2023.1707
Vibration Characteristics Analysis of O-Shaped Damping Ring to Balance Damping Gear Transmission System for Three-Cylinder Engine
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: balance damping gear, O-shaped damping ring, three-cylinder engine, vibration characteristics
Balance shafts are often used to improve the engine vibration characteristics of three-cylinder engines. The balance damping gear with a damping ring is an important part connecting the crankshaft and the balance shaft transmission. The stiffness characteristics of the damping ring and the unbalance of the gear have an important influence on its vibration suppression performance, but the coupled influence of the stiffness characteristics of the damping ring and the unbalanced characteristics of the vibration damping gear is unknown. In this paper, a multi-body dynamic bending−torsional coupling model of the transmission system of a three-cylinder engine with a balance damping gear is constructed considering the equivalent stiffness of the balance shaft support. Based on the fourth-order Runge−Kutta method, the influence laws of different rotational speeds, load torques, gear unbalance, radial stiffness and torsional stiffness of the damping ring on the vibration characteristics of the... [more]
37424. LAPSE:2023.1706
Study on Dynamic Failure Characteristics of Coal and Rock in Stope Induced by Dynamic Load of Steep Horizontal Sublevel Mining
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: acoustic emission, horizontal sublevel mining, overburden failure characteristics, response characteristics, steeply inclined coal seam
In this paper, through a similar simulation experiment, the roof rock breaking situation of horizontal sublevel caving method in extremely thick and steep inclined coal seam is studied, and the response characteristics of coal and rock mass under different dynamic load strength are analyzed. The mechanical response mechanisms of different mining positions under the influence of dynamic load and the law characteristics of the surrounding rock from elastic deformation to impact failure are revealed. The study shows that with the increase in the horizontal sublevel mining depth, the roof is gradually broken from the suspended state, and the broken block fills the goaf. The thin rock strata form a granular structure, and the thick rock strata form a block splicing and occlusion structure. On the same side of the coal seam floor, the concentrated stress gradually increases, and the closer the distance from the goaf is, the more obvious the stress change in the coal body below is. With the i... [more]
37425. LAPSE:2023.1705
Bojungikki-Tang Enhances the Effect of PD-1 Blockade in a Syngeneic Murine Model of Lung Carcinoma
February 21, 2023 (v1)
Subject: Biosystems
Keywords: Bojungikki-Tang, immunotherapy, KLN205, lung cancer, PD-1, tumor microenvironment
Although immunotherapy has become the standard of treatment for non-small cell lung cancer (NSCLC), only a limited number of patients benefit from it clinically because of the resistance to immunotherapeutic agents. Of late, the usefulness of herbal medicines in combination with immunotherapy has been investigated. Bojungikki-Tang (BJIKT) is a widely used traditional herbal medicine. It synergistically enhances the antitumor effects of chemotherapy and regulates the immune responses in cancer, but its antitumor effect with immunotherapy in NSCLC is unclear. In this study, we investigated the combined effects of BJIKT and an anti-PD-1 antibody in a KLN205-DBA/2 syngeneic lung cancer model. Immunohistochemistry and flow cytometry analyses were performed to analyze the changes in immune cells in the tumor microenvironment. BJIKT plus an anti-PD-1 antibody treatment significantly inhibited tumor growth, unlike the respective monotherapies. Compared to monotherapy, the combination treatment... [more]
37426. LAPSE:2023.1704
Theoretical-Experimental Analysis of the Performance of Geothermal Heat Pumps for Air Conditioning Greenhouses in Arid Zones
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: geothermal energy, geothermal heat exchanger, geothermal heat pump, greenhouse, renewable energies, sustainable technology, TRNSyS simulation
This study shows the results of a simulation tool using the TRNSyS 2017 simulator, validated with experimental data from a greenhouse in an arid zone in northwestern Mexico. Additionally, experimental data on the performance of geothermal heat pumps are shown during the year 2020 in heating and cooling mode. With this information, an average deviation of the simulator for the outlet fluid temperature of the geothermal heat exchanger (GHE) of 2.77% and an average deviation of the coefficient of performance in cooling mode (EER) of the geothermal heat pump (GHP) of 3.7% was obtained. In the experimental study, it was observed that in the last 2 weeks of July and the first 2 weeks of August, the subsoil is saturated, which causes a decrease in the thermal inertia of the GHE. During the experimental study, it was possible to determine that the flow indicated in the GHE to obtain the highest performance of the GHP system in greenhouses in arid zones corresponds to 1 GPM, obtaining an EER of... [more]
37427. LAPSE:2023.1703
Supply Chain Management: A Review and Bibliometric Analysis
February 21, 2023 (v1)
Subject: Planning & Scheduling
Keywords: bibliometric analysis, block chain, Industry 4.0, supply chain management (SCM), Sustainability
Supply chain management (SCM), which generally refers to horizontal integration management, has steadily become the core competitiveness of company rivalry and an essential approach to developing national comprehensive and national strength since the end of the 20th century due to the numerous needs arising from a competitive international economy. Manufacturers develop a community of interest by forming long-term strategic partnerships with suppliers and vendors throughout the supply chain. This paper defines supply chain management by reviewing the existing literature and discusses the current state of supply chain management research, as well as prospective research directions. Specifically, we conducted a bibliometric analysis of the influential studies of SCM in terms of various aspects, such as research areas, journals, countries/regions, institutions, authors and corresponding authors, most cited publications, and author keywords, based on the 8998 reviews and articles collected... [more]
37428. LAPSE:2023.1702
Development of a Moving Bed Reactor for Thermochemical Heat Storage Based on Granulated Ca(OH)2
February 21, 2023 (v1)
Subject: Materials
Keywords: calcium hydroxide, nanocoated particle stabilization, reactive moving bed, thermochemical storage
Calcium hydroxide is promising for thermal energy storage due to its low cost and high energy density. Nevertheless, the powdered material is cohesive and has low thermal conductivity which is a major challenge for the operation of moving bed reactors. One approach to facilitate the movement of the reaction bed is the stabilisation of the particles through the coating of Ca(OH)2 granules with Al2O3 particles. In this work, a newly designed reactor concept was specifically developed for testing coated Ca(OH)2 granules. The design allows for the movement of the reaction bed by gravity assistance and direct heating of the particles by a counter current gas flow. The operation was successfully demonstrated and proved to achieve high heat transfer between gas and granules. Furthermore, the movement of the reaction bed was achieved after the discharging phase. Two batches of uncoated and coated Ca(OH)2 granules were subject of 10 thermochemical cycles in this reactor. The cycling stability,... [more]
37429. LAPSE:2023.1701
Fault Diagnosis of Permanent Magnet Synchronous Motor of Coal Mine Belt Conveyor Based on Digital Twin and ISSA-RF
February 21, 2023 (v1)
Subject: Modelling and Simulations
Keywords: belt conveyor, digital twin, fault diagnosis, permanent magnet synchronous motor, Random Forest, sparrow search optimized algorithm
Permanent magnet synchronous motors (PMSMs) have been gradually used as the driving equipment of coal mine belt conveyors. To ensure safety and stability, it is necessary to carry out real-time and accurate fault diagnosis of PMSM. Therefore, a fault diagnosis method for PMSM based on digital twin and ISSA-RF (Improved Sparrow Search Algorithm Optimized Random Forest) is proposed. Firstly, the multi-strategy hybrid ISSA is used to solve the problems of uneven population distribution, insufficient population diversity, low convergence speed, etc. In addition, the fault diagnosis model of ISSA-RF permanent magnet synchronous motor is constructed based on the optimization of the number of Random Forest decision trees and that of features of each node by ISSA. Secondly, considering the operation mechanism and physical properties of PMSM, the relevant digital twin model is constructed and the real-time mapping of physical entity and virtual model is realized through data interactive transmi... [more]
37430. LAPSE:2023.1700
Research on Casing Deformation Prevention Technology of a Deep Shale Gas Well Based on Cementing Slurry System Optimization
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: casing deformation, cement slurry, external extrusion, shale gas, shearing
In the complex fracturing process of shale gas wells, casing is subjected to serious deformation, which can easily to the failure of wellbore integrity and the reduction of well construction productivity. It is particularly important to clarify the casing deformation mechanism and carry out effective control. Based on the logging data of casing deformation from well and full-scale indoor tests, the casing deformation mechanism is mainly considered to be shear and non-uniform extrusion deformation caused by formation slip and displacement control, i.e., the ultimate working conditions. The slip displacement boundary (<40 mm) under complex fracturing conditions is quantified to provide the design and optimization basis. Then, the influence laws of steel grade and wall thickness on the shear and non-uniform extrusion bearing characteristics are studied, using unconventional oil and gas well casing simulation test systems for 110 ksi (φ139.7 × 10.54 mm) and 125 ksi (φ139.7 × 12.7 mm) ca... [more]
37431. LAPSE:2023.1699
Design and Fabrication Process Optimization of Silver-Based Inkjet-Printed Microheater
February 21, 2023 (v1)
Subject: Process Design
Keywords: COMSOL, gas sensor, inkjet printing, microheater, polymer substrate, printed electronics
This paper examines the simulation, design, and fabrication of a nano-particle silver microheater. COMSOL Multiphysics is used to simulate the microheater of an area of 720 × 720 μm2. Different stages of the microheater fabrication process are discussed. The size of the cartridge used is 10 pL and the nozzle diameter was 50 μm. The drop spacing was chosen to be 45 μm after testing several different values. Controlled printing of Ag ink was reached by setting the tickle control frequency to 8 kHz and cartridge print height to 0.4 mm. The nozzle temperature was set at ambient temperature. The inkjet printed microheater is of same area and track and gap widths of 110 μm. The measured resistance of the microheater, 119 Ω, is approximately equal to the simulated resistance of 100 Ω. It was observed that the temperature at the center of the heater reaches up to 250 °C.
37432. LAPSE:2023.1698
Fast Finite-Time Stability and Its Application in Adaptive Control of High-Order Stochastic Nonlinear Systems
February 21, 2023 (v1)
Subject: Process Control
Keywords: adaptive control, fast finite-time stability, high-order stochastic nonlinear systems, state feedback
In this article, a new design method for an adaptive fast finite-time controller (FTC) is proposed for the finite-time stability (FTS) issue of a class of high-order stochastic nonlinear systems (HOSNSs) with unknown parameters. Using a power integrator technology and Lyapunov function approach, an adaptive state feedback controller is derived to ensure fast FTS of HOSNSs. The developed adaptive fast FTC is equipped with less settling time to obtain better steady-state accuracy compared with the traditional FTC. The effectiveness of the proposed adaptive control scheme is demonstrated by a numerical example.
37433. LAPSE:2023.1697
Motion Planning of an Inchworm Robot Based on Improved Adaptive PSO
February 21, 2023 (v1)
Subject: Planning & Scheduling
Keywords: improved adaptive PSO, inchworm robot, motion planning, seventh-degree polynomial programming
Focusing on the motion energy consumption of a self-developed inchworm robot’s peristaltic gait, based on the “error tracking” of cubic polynomial programming in Cartesian space and seventh polynomial programming in joint space, we propose an optimal motion planning method of energy consumption considering both kinematic and dynamic constraints. Firstly, we offer a mathematical description of the energy consumption and space curve similarity operator. Secondly, we describe the mathematical models of the robot trajectory and path that were established in terms of their dynamics and kinematics. Then, we propose a motion planning method based on improved adaptive particle swarm optimization (PSO) to accelerate the convergence speed of the algorithm and ensure the accuracy of the model calculation. Finally, we outline the simulation test carried out to measure the inchworm-like robot’s creeping gait. The results show that the motion path obtained by using the planning method proposed in th... [more]
37434. LAPSE:2023.1696
Research on Position Control of an Electro−Hydraulic Servo Closed Pump Control System
February 21, 2023 (v1)
Subject: Process Control
Keywords: adaptive backstep sliding mode, dead-zone inverse compensation, electro–hydraulic servo pump control, position control
A control strategy combining adaptive backstep sliding mode control and dead-zone inverse compensation control in a series was proposed to solve the problem of system parameter uncertainty and system dead-zone in the process of position control in an electro−hydraulic servo closed pump control system. Firstly, an adaptive backstepping sliding mode controller was designed by introducing the sliding mode control principle. Secondly, the smooth dead-zone inverse function was constructed by using the smooth continuous index function to design the dead-zone inverse compensation controller, which is combined with the adaptive sliding mode controller to form a series controller. Finally, the feasibility of the controller was verified by using the pump control servo system of a lithium battery pole strip mill. The experimental results show that, compared with traditional PID control, the control strategy displayed no excessive overshoot before the steady state, the steady-state control accurac... [more]
37435. LAPSE:2023.1695
Expression Analysis of BIRC3 as One Target Gene of Transcription Factor NF-κB for Esophageal Cancer
February 21, 2023 (v1)
Subject: Biosystems
Keywords: BIRC3, cytokine, esophageal cancer, transcription factor, tumor necrosis factor α (TNFα)
Esophageal cancer (ESCA) is one of the highest lethal malignancy tumors worldwide. Baculoviral IAP repeat-containing protein 3 (BIRC3) is the main inhibitor of apoptosis in many malignancies. The aim of this study was to clarify how BIRC3 acts in ESCA cells. Through TNMplot and GEPIA2 analysis, BIRC3 was found abundantly expressed in ESCA cells. The quantitative RT-PCR assay confirmed BIRC3 was pronouncedly induced in all used ESCA cell lines. In addition, proinflammatory cytokines TNFα and IL-1β were shown to have promotion effects on BIRC3 expression in ESCA cells. These promotive effects were blocked when the function of NF-κB was inhibited by bay 11-7082, which indicates the expression of the BIRC3 gene was regulated via the NF-κB transcription pathway in ESCA. Moreover, bioinformatics analysis showed that the BIRC3 gene had many NF-κB binding cis-elements. Chromatin immunoprecipitation was then performed and it was found that NF-κB directly interacts with cis-elements of the... [more]
37436. LAPSE:2023.1694
A Comparison of Three Different Group Intelligence Algorithms for Hyperspectral Imagery Classification
February 21, 2023 (v1)
Subject: Numerical Methods and Statistics
Keywords: classification, feature extraction, hyperspectral remote sensing, image
The classification effect of hyperspectral remote sensing images is greatly affected by the problem of dimensionality. Feature extraction, as a common dimension reduction method, can make up for the deficiency of the classification of hyperspectral remote sensing images. However, different feature extraction methods and classification methods adapt to different conditions and lack comprehensive comparative analysis. Therefore, principal component analysis (PCA), linear discriminant analysis (LDA), and locality preserving projections (LPP) were selected to reduce the dimensionality of hyperspectral remote sensing images, and subsequently, support vector machine (SVM), random forest (RF), and the k-nearest neighbor (KNN) were used to classify the output images, respectively. In the experiment, two hyperspectral remote sensing data groups were used to evaluate the nine combination methods. The experimental results show that the classification effect of the combination method when applying... [more]
37437. LAPSE:2023.1693
Optimization of the Sustainable Distribution Supply Chain Using the Lean Value Stream Mapping 4.0 Tool: A Case Study of the Automotive Wiring Industry
February 21, 2023 (v1)
Subject: Planning & Scheduling
Keywords: automobile, durability, logistics 4.0, methodology, VSM, wiring
The transformation to Supply Chain (SC) 4.0 promises new opportunities for companies to gain competitiveness. The Lean Value Stream Mapping (VSM) tool allows the supervision of all the processes of the entire SC, from which we can identify the different types of waste that hinder the competitiveness of the SC. Following the existing problems detected with the help of a diagnostic, we will propose a new process design by integrating 4.0 technologies to modernize the company. For our case study, we treat the multinational SC of Automotive Wiring Equipment Morocco, where we will focus on the downstream part of the SC composed of the warehouse and the different stages of road and sea transport until the final delivery in Austria. Then, we will consider the opportunities offered by each country in terms of logistics competitiveness. In this research work, we will show how Lean VSM4.0 will contribute to sustainable development by integrating the three pillars economic, environmental, and soc... [more]
37438. LAPSE:2023.1692
Eugenol, Isolated from the Essential Oil from Lonicera japonica Flower Buds, Could Increase the Oxidative Stability of Sunflower Oil in the Deep-Frying Procedure of Youtiao
February 21, 2023 (v1)
Subject: Food & Agricultural Processes
Keywords: eugenol, Lonicera japonica, oxidative stability, sensory attributes, sunflower oil
In order to assess the sunflower oil (SFO) oxidative stability that was added by the essential oils extracted from Lonicera japonica flower buds (LJEO) during deep-frying at 180 °C for 30 h, we clarified the compound/compounds of LJEO that improved the oxidative stability of SFO. The results displayed that the addition of LJEO (0.06 g/kg) could significantly restrict the elevation or the reduction in the levels of total polar compounds (TPC), thiobarbituric acid (TBA), conjugated dienes and conjugated trienes, and the values for polymer, viscosity and the color of SFO during the whole period. Meanwhile, the reduction in the sensory attributes, including flavor, taste, crispness and overall acceptability of the fried product, youtiao, was obviously restricted as well. After the bioassay-guided fractionation of LJEO and repeated deep-frying at 180 °C for 30 h, one of its chemical constituents, eugenol, was demonstrated to be the very compound that did significantly inhibit the oxidative... [more]
37439. LAPSE:2023.1691
Movement Law of Methane Drained by Large-Diameter Borehole Drilling Machine in the Goaf
February 21, 2023 (v1)
Subject: Modelling and Simulations
Keywords: “U” type ventilation, flow field in the goaf, fluent simulation, large-diameter borehole, upper corner
To study the movement law of methane in the goaf drained by a large-diameter borehole drilling machine under “U”-shaped ventilation, a simulation on a coal mine was conducted on Fluent to find the optimal spacing between large-diameter boreholes and the most appropriate distance between the borehole and the upper corner. The variation of borehole drilling and the methane concentration in the upper corner were obtained through a field test. Results show that the method of drilling large-diameter boreholes greatly reduces the methane concentration in the goaf and the upper corner, with the optimal borehole spacing being 30 m and the most appropriate distance between the borehole and the upper corner being 15 m. When the large-diameter borehole is drilled 25 m deep down into the goaf, it penetrates into the stress impact area, and the methane concentration increases rapidly, with the maximum being 3.7%. When the borehole is drilled 35 m down into the goaf, the methane concentration slight... [more]
37440. LAPSE:2023.1690
A Systematic Review on Waste as Sustainable Feedstock for Bioactive Molecules—Extraction as Isolation Technology
February 21, 2023 (v1)
Subject: Environment
Keywords: bioactive molecules, Biomass, biorefinery, circular economy, Extraction, residue, secondary metabolite, waste
In today’s linear economy, waste streams, environmental pollution, and social−economic differences are increasing with population growth. The need to develop towards a circular economy is obvious, especially since waste streams are composed of valuable compounds. Waste is a heterogeneous and complex matrix, the selective isolation of, for example, polyphenolic compounds, is challenging due to its energy efficiency and at least partially its selectivity. Extraction is handled as an emerging technology in biorefinery approaches. Conventional solid liquid extraction with organic solvents is hazardous and environmentally unfriendly. New extraction methods and green solvents open a wider scope of applications. This research focuses on the question of whether these methods and solvents are suitable to replace their organic counterparts and on the definition of parameters to optimize the processes. This review deals with the process development of agro-food industrial waste streams for bioref... [more]
37441. LAPSE:2023.1689
Preheating of Lithium-Ion Battery Electrodes as Basis for Heated Calendering—A Numerical Approach
February 21, 2023 (v1)
Subject: Energy Systems
Keywords: battery, calendering, cathode, electrode production, heat transfer
Lithium-ion batteries are state of the art and, still, their performance is constantly improving. To increase the energy density and electric conductivity, electrodes are usually calendered. Hereby, a higher degree of compaction, while reducing structural damage, can be reached by heating the calendering rolls. For industrially relevant line speeds, it is however questionable whether the contact time between electrode and roll is sufficient to reach the full positive effect of the increased temperature. This study shows a numerical approach based on the discrete element method to simulate the heating behavior of electrodes before and during calendering using a typical NMC-622-cathode as a model structure. To improve the results of existing, more simplified discrete element method simulations, which neglect the heat transfer through the carbon black−binder matrix, an extension with heat transfer through the carbon black−binder matrix has been implemented. Considering process parameters,... [more]
37442. LAPSE:2023.1688
Synthesis and Mechanism Study of Temperature- and Salt-Resistant Amphoteric Polyacrylamide with MAPTAC and DTAB as Monomers
February 21, 2023 (v1)
Subject: Materials
Keywords: acid fracturing, high temperature resistance, polyacrylamide, thickener, viscosity loss rate
The failure of thickeners at high temperature results in gelled acid acidification fracturing. To solve the problem, 8 kinds of polymers were synthesized by free radical polymerization of aqueous solution using AM, AMPS, NaAMPS, MAPTAC, DTAB and NVP as raw materials. The polymer was characterized by infrared spectroscopy and viscosity-average molecular weight, and the temperature resistance, rheology, salt resistance and shear resistance of the polymer solution were compared, and the mechanism was analyzed. The results show that the viscosity of GTY−2 is 181.52 mPa·s, and the viscosity loss rate is 56.89% at 180 °C and 100 s−1, and its temperature resistance is the best. Meanwhile, the viscosity retention rate of GTY−2 is 84.58% after 160 min shear, showing the strongest shear resistance. The viscosity loss rate of GTY−1 in 20% hydrochloric acid solution is 80.88%, and its acid resistance is stronger than that of GTY−2. Moreover, due to the amphiphilicity of DTAB, the molecular hydrati... [more]
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