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Showing records 37900 to 37924 of 43292. [First] Page: 1 1513 1514 1515 1516 1517 1518 1519 1520 1521 Last
Estimation of Water Vapor Density in Adiabatic Mixing of Cryogenic Gas and Moist Air
Xiangyu Shao, Quanwei Deng, Min Jiang, Qiang Chen
February 21, 2023 (v1)
Keywords: adiabatic mixing, cryogenic fuels, leak monitoring, water vapor density
Concentration distribution is essential for the emergency disposal of cryogenic fuel leakage. In the dispersion process of cryogenic gas, its concentration is greatly influenced by the atmospheric water vapor. The authors have presented an adiabatic mixing model to derive the concentration of the cryogenic gas, in which the value of water vapor density is obtained by referring to the NIST database continuously. However, it is difficult to achieve fast system response times for real-time monitoring systems when calling NIST. Thus, a simple algebraic model of water vapor density with high calculation efficiency is necessary. Based on the detection of temperature and the solution of water vapor partial pressure, a calculation model was developed. For a given initial ambient temperature and relative humidity, the dew point could be solved by Qian’s correlation. By temperature comparisons of the mixture cloud, dew point, and triple point, the water vapor partial pressure can be calculated b... [more]
Two-Dimensional Age Replacement Decision for Structural Dependence Parallel Systems via Intelligent Optimization Algorithm
Enzhi Dong, Zhonghua Cheng, Rongcai Wang, Shuai Yue
February 21, 2023 (v1)
Subject: Optimization
Keywords: copula function, intelligent optimization algorithm, maintenance, parallel system, structural dependence, two-dimensional age replacement
From large-scale aerospace systems to household appliances and other systems in daily life, the application of parallel systems is involved. A parallel system is a typical structural dependence multi-component system, in addition to a series system and hybrid system. This paper takes a parallel system as the research object and minimizes the expected cost rate or maximizes the availability by determining the optimal two-dimensional age replacement interval. The structural dependence of the components is described by the copula function, and the system life model is established. Based on the system life model, the two-dimensional age replacement expected cost rate model and availability model are proposed. In case analysis, the simulated annealing algorithm (SAA), genetic algorithm (GA) and particle swarm optimization (PSO) algorithm are used to find the optimal warranty scheme for the engine fuel fine filter. SAA can converge faster and find a warranty scheme that makes the warranty co... [more]
New Multi-Leg Converter for DC Microgrid with Two Duty Cycles
Mahajan Sagar Bhaskar, Dhafer Almakhles
February 21, 2023 (v1)
Keywords: active–passive leg, DC microgrid, DC-to-DC converter, multi-leg structure, SDG 12, SDG 7, SDG 9, triple mode converter, two-duty control
In recent times, important contributions and the incorporation of renewable sources, such as photovoltaic, fuel cells, etc., are the main reasons for the popularity of DC microgrids. Integrating renewable sources into the microgrid requires high-voltage, high-efficiency DC-to-DC converters. Without modification, traditional converters are not suitable for achieving the required voltage in microgrid applications, due to the requirement for a large duty cycle, inductor resistance, voltage rating of switches, reverse recovery of the diode, high current rating inductors, etc. Various converters based on the circuitry of voltage multipliers, switched inductors/capacitors, coupled inductors, transformers, etc., have been proposed in the literature and have their drawbacks. In this paper, to realize significant voltage gain with two duty cycle controls, a new multi-leg (ML) converter is recommended as a solution for use in DC microgrids. The converter is designed by incorporating multiple leg... [more]
Comprehensive Review of Hydrothermal Pretreatment Parameters Affecting Fermentation and Anaerobic Digestion of Municipal Sludge
Farokh Laqa Kakar, Frew Tadesse, Elsayed Elbeshbishy
February 21, 2023 (v1)
Subject: Environment
Keywords: anaerobic digestion, biogas, Fermentation, hydrothermal pretreatment, thickened waste-activated sludge, volatile fatty acids
Municipal solid waste treatment and disposal have become one of the major concerns in waste management due to the excessive production of waste and higher levels of pollution. To address these challenges and protect the environment in sustainable ways, the hydrothermal pretreatment (HTP) technique coupled with anaerobic digestion (AD) becomes a preferred alternative technology that can be used for municipal solid waste stabilization and the production of renewable energy. However, the impact of HTP parameters such as temperature, retention time, pH, and solid content on the fermentation of TWAS is yet to be well studied and analyzed. Hence this study was conducted to review the effect of hydrothermal pretreatment of thickened waste-activated sludge (TWAS) on fermentation and anaerobic digestion processes. Many studies reported that fermentation of TWAS at pretreatment temperature ranges from 160 °C to 180 °C resulted in a 50% increase in volatile fatty acid (VFA) yields compared to no... [more]
Influence of Encapsulation Parameters on the Retention of Polyphenols in Blackthorn Flower Extract
Nikolina Gaćina, Ivona Elez Garofulić, Zoran Zorić, Sandra Pedisić, Verica Dragović-Uzelac
February 21, 2023 (v1)
Subject: Materials
Keywords: blackthorn flowers, polyphenols, spray-drying, UPLC-MS/MS, wall material
In order to utilize the benefits of blackthorn flower polyphenols and provide their stabilization during processing and storage, and to facilitate their application in functional food products, this study aimed to evaluate the encapsulation parameters during the spray-drying process of blackthorn flower extract. The effect of the type of wall material (maltodextrin (MD) and its mixtures with gum arabic (GA) and inulin (IN)), its ratio to extract dry matter (0.5, 1, and 2) and drying temperature (120, 150, and 180 °C) on the concentration of different polyphenolic groups was studied. While the lowest applied amount of wall material at the lowest drying temperature enabled efficient encapsulation of all polyphenolic groups, the type of wall material applied caused significant differences in retention. The highest concentrations of both phenolic acids and flavonoids were achieved with the addition of 25% of GA in MD. Unlike the addition of GA, mixtures of MD with IN did not show a positiv... [more]
Research and Practice of Risk Early Warning Technology for Lost Circulation with Drilling under the Conditions of Geological Engineering Information Fusion: The Example of the Yuanba Area
Zhikun Liu, Rongtao Luo, Zhe Yang, Linjie Wang, Liupeng Wang
February 21, 2023 (v1)
Keywords: geological engineering information fusion, risk warning for lost circulation, three dimensional geomechanical model, Yuanba district
In the Yuanba area, many lost circulation accidents occur due to the complex geological structure, broken strata, and developed fractures, which seriously affect construction safety and drilling costs. Therefore, the Yuanba district is the focus of this paper. Firstly, a three-dimensional geomechanical model is established through multi-source information fusion to identify the main geological risk factors of lost circulation, according to the data on drilling and well logging in the operation area. Then a risk warning model and evaluation methods for loss circulation, based on geological engineering data fusion, are established, through which the characteristic parameters of various loss of circulation risks can be calculated in real time, parameters along the well trajectory can be extracted and compared, and thus, the risk of lost circulation is warned and analyzed in real time. The early warning of lost circulation risk can be achieved during drilling operations, which can improve... [more]
Music Generation System for Adversarial Training Based on Deep Learning
Jun Min, Zhaoqi Liu, Lei Wang, Dongyang Li, Maoqing Zhang, Yantai Huang
February 21, 2023 (v1)
Keywords: artificial intelligence (AI), GANs, music generation, natural language processing, transformer
With the rapid development of artificial intelligence, the application of this new technology to music generation has attracted more attention and achieved gratifying results. This study proposes a method for combining the transformer deep-learning model with generative adversarial networks (GANs) to explore a more competitive music generation algorithm. The idea of text generation in natural language processing (NLP) was used for reference, and a unique loss function was designed for the model. The training process solves the problem of a nondifferentiable gradient in generating music. Compared with the problem that LSTM cannot deal with long sequence music, the model based on transformer and GANs can extract the relationship in the notes of long sequence music samples and learn the rules of music composition well. At the same time, the optimized transformer and GANs model has obvious advantages in the complexity of the system and the accuracy of generating notes.
Reinforcement Learning Control with Deep Deterministic Policy Gradient Algorithm for Multivariable pH Process
Chanin Panjapornpon, Patcharapol Chinchalongporn, Santi Bardeeniz, Ratthanita Makkayatorn, Witchaya Wongpunnawat
February 21, 2023 (v1)
Subject: Energy Policy
Keywords: Artificial Intelligence, deterministic deep policy gradient, grid search, pH control, reinforcement learning
The pH treatment unit is widely used in various processes, such as wastewater treatment, pharmaceutical manufacturing, and fermentation. It is essential to get the on-specifications product. Thus, controlling pH is key management for accomplishing the manufacturing objective. However, the highly nonlinear pH characteristics of acid−base titration make pH regulation difficult. Applications of artificial intelligence for process control have progressed and gained popularity recently. The development of reinforcement learning (RL) control with a deep deterministic policy gradient (DDPG) algorithm to handle coupled pH and liquid level control in a continuous stirred tank reactor with a strong acid−base reaction is presented in this study. To validate the RL model, the reward functions are created individually for the level and pH controls. The grid search technique is deployed to optimize the hyperparameters of the RL controller models, including the number of nodes in the hidden layers an... [more]
A Hybrid Euler−Lagrange Model for the Paint Atomization Process of Air Spraying
Shiming Chen, Yan Chen, Zhaojie Wu, Junze Jiang, Jiang Li, Weixing Hua
February 21, 2023 (v1)
Keywords: air spraying, atomization model, CFD numerical simulation, Euler–Lagrange method, model credibility analysis, multi-scale, robot, spray gun trajectory planning
The modeling of the paint atomization process is a barrier in computational fluid dynamics numerical simulation for the whole process of air spraying, and seriously restricts robot intelligent spray gun trajectory planning and the improvement of coating quality. Consequently, a multi-scale paint atomization model based on the hybrid Euler−Lagrange method was established in this paper, which included a large liquid micelle motion model, a particle motion model, and a turbulence flow model. The Euler method was adopted to capture the gas−liquid interface in the atomization flow field to describe the deformation and motion of large liquid micelles. The identification and transformation mechanisms of large liquid micelles and small particles were constructed by the particle motion model, and the motion of small droplets generated by paint atomization was tracked by the Lagrange method. The turbulence motion of the fluid in the process of paint atomization was described by a two-equation tu... [more]
Doubling the Space-Time Yield of a Pilot Biogas Reactor with Swine Manure and Cereal Residues by a Closed Loop Feedback Control Based on an Automated Fuzzy Logic Control System
Paul Scherer, Anja Schreiber, Richard Arthur, Sebastian Antonczyk, Gerhard-Rainer Vollmer
February 21, 2023 (v1)
Keywords: anaerobic digestion, biogas, Biomass, energy crops, Fuzzy, manure, process control
The anaerobic digestion of swine manure was performed for more than 2 years in a biogas pilot plant with cereal residues as a mono-input, either by a simple intermittent substrate feeding or by feeding with an automated “autopilot” system under the direction of a Fuzzy logic control (FLC) system, working with a closed-loop feedback control. The pilot plant of the University of Applied Sciences in Nordhausen consisted of a 2.5 m3 dosage tank, a 2.5 m3 digestate tank, and a 1 m3 biogas reactor. Only three control parameters were used for FLC: pH, methane %, and the specific gas production rate (GPR) related to the organic loading rate (OLR), that is GPR/OLR m3 biogas/(kgVS d), vs = volatile solids. The specific GPR was referred to the OLR of the last feeding every 8 h in terms of kgVS/(m3 d). In test period I without an FLC system, a safe process with just an OLR of 4 kgVS/(m3 d) was reached, followed by an overloading and reactor disturbance at ≤6.3 kgVS/(m3 d) as indicated by acidifica... [more]
Nature-Derived Compounds as Potential Bioactive Leads against CDK9-Induced Cancer: Computational and Network Pharmacology Approaches
Abu Saim Mohammad Saikat, Khattab Al-Khafaji, Hafeza Akter, Jong-Gu Choi, Mahbub Hasan, Sang-Suk Lee
February 21, 2023 (v1)
Subject: Biosystems
Keywords: CDK9, CDK9-induced cancer, free energy landscape, molecular docking, molecular dynamics, network pharmacology, PPI network
Given the importance of cyclin-dependent kinases (CDKs) in the maintenance of cell development, gene transcription, and other essential biological operations, CDK blockers have been generated to manage a variety of disorders resulting from CDK irregularities. Furthermore, CDK9 has a crucial role in transcription by regulating short-lived anti-apoptotic genes necessary for cancer cell persistence. Addressing CDK9 with blockers has consequently emerged as a promising treatment for cancer. This study scrutinizes the effectiveness of nature-derived compounds (geniposidic acid, quercetin, geniposide, curcumin, and withanolide C) against CDK9 through computational approaches. A molecular docking study was performed after preparing the protein and the ligands. The selected blockers of the CDK9 exerted reliable binding affinities (−8.114 kcal/mol to −13.908 kcal/mol) against the selected protein, resulting in promising candidates compared to the co-crystallized ligand (LCI). The binding affini... [more]
Leaching Behavior of the Main Metals from Copper Anode Slime during the Pretreatment Stage of the Kaldor Furnace Smelting Process
Hong Zeng, Fupeng Liu, Songlin Zhou, Chunfa Liao, Feixiong Chen, Yanliang Zeng
February 21, 2023 (v1)
Subject: Optimization
Keywords: copper anode slime, Kaldor furnace smelting process, leaching behavior, precious metals, pressure acid leaching
The Kaldor furnace smelting process is currently the mainstream process for treating copper anode slime, but the existence of copper, tellurium and other impurities has adverse effects on the recovery of gold and silver during the Kaldor furnace smelting stage. Therefore, it is necessary to pretreat the copper anode slime to remove these impurities before Kaldor furnace reduction smelting. However, the current pretreatment process of copper anode slime generally has the problem of low removal efficiency of copper and tellurium, and little research on the occurrence state of main metals in copper anode slime. Therefore, this study quantitatively determined the phase composition of Cu, Te, Pb, Bi, As, Sb, Se, Ag and Au, and hydrogen peroxide was introduced to enhance the leaching of impurities. The leaching behavior of each metal in copper anode slime was investigated in detail. The results demonstrate that Cu and Te in the copper anode slime mainly exist in the form of CuO and CuSO4 and... [more]
Polystyrene-Based Single-Ion Conducting Polymer Electrolyte for Lithium Metal Batteries
Daria Voropaeva, Svetlana Novikova, Nikolay Trofimenko, Andrey Yaroslavtsev
February 21, 2023 (v1)
Keywords: ionic conductivity, LFP, lithium metal, lithium metal battery, polymer electrolyte, single-ion conductor
Lithium metal batteries are one of the more promising replacements for lithium-ion batteries owing to their ability to reach high energy densities. The main problem limiting their commercial application is the formation of dendrites, which significantly reduces their durability and renders the batteries unsafe. In the present work, we used a single-ion conducting gel polymer electrolyte based on a poly(ethylene-ran-butylene)-block-polystyrene (SEBS) block copolymer, which was functionalized with benzenesulfonylimide anions and plasticized by a mixture of ethylene carbonate and dimethylacetamide (SSEBS-Ph-EC-DMA), with a solvent uptake of 160% (~12 solvent molecules per one functional group of the membrane). The SSEBS-Ph-EC-DMA electrolyte exhibits an ionic conductivity of 0.6 mSm∙cm−1 at 25 °C and appears to be a cationic conductor (TLi+ = 0.72). SSEBS-Ph-EC-DMA is electrochemically stable up to 4.1 V. Symmetrical Li|Li cells; further, with regard to SSEBS-Ph-EC-DMA membrane electrolyt... [more]
Numerical Simulation of Multifracture Growth under Extremely Limited Entry Fracturing of Horizontal Well
Tengfei Wang, Ming Chen, Yun Xu, Dingwei Weng, Zhanwei Yang, Zhaolong Liu, Zeyuan Ma, Hao Jiang
February 21, 2023 (v1)
Keywords: extremely limited entry, fluid allocation, fracture extension, multi-cluster fracturing, planar 3D model
The multifracture competitive growth from a horizontal well is an essential issue in multi-cluster fracturing design. In recent years, extremely limited entry (ELE) fracturing has been implemented to promote uniform multifracture growth. However, the mechanism of multifracture growth and ELE design remain unclear. Based on the planar three-dimensional multifracture propagation model, a multi-cluster horizontal well fracturing model that considers ELE design has been developed. The model considers flow in the wellbore and fluid filtration loss in the fracture. The simulator enables the simulation and analysis of non-uniform in situ stress, filtration loss, and fracture properties. Using this program, we simulated the propagation process of multiple clusters of fractures in ELE fracturing of horizontal wells. The results show the following: The perforation friction in the ELE fracturing can counteract the difference in fluid allocation caused by stress interference, allowing all clusters... [more]
Level Control of Blast Furnace Gas Cleaning Tank System with Fuzzy Based Gain Regulation for Model Reference Adaptive Controller
Özgür Aslan, Aytaç Altan, Rıfat Hacıoğlu
February 21, 2023 (v1)
Keywords: blast furnace gas cleaning tank system, fuzzy MRAC, iron making processes, MRAC, PID
Iron making processes and automation systems are mostly controlled by logical rules and PID controllers. The dynamic behavior of these processes varies due to factors such as raw materials, outdoor conditions, and equipment aging. Changes in system dynamics necessitate re-determination of PID controller parameters. Model reference adaptive controllers (MRACs) are used in many industrial application areas with their adaptability to variable conditions. In this study, an MRAC is applied in the gas cleaning tank system level control problem in the blast furnace facility, which is at the center of the iron making processes. In addition, fuzzy based gain regulation is proposed to improve MRAC performance. MRAC and PID controller system control results are observed and compared. The fast response and adaptation performance of the proposed fuzzy MRAC approach along with external disturbance effects are analyzed. Fuzzy based gain regulation MRAC performances show better performance especially... [more]
The Cell Wall Regeneration of Tobacco Protoplasts Based on Microfluidic System
Songzhi Xu, Zhanghua Sun, Lili Liu, Ying Yang, Shuangyu Zhang, Ying Li, Ning Bao, Yali Zhang, Lijun Sun
February 21, 2023 (v1)
Keywords: BTH, cell wall regeneration, microfluidic system, protoplast, Pst DC3000
The cell wall, serving as the exoskeleton of plants, is naturally a barrier to resist external stresses. Protoplasts can be obtained by dissolving the cell walls of plant cells without damaging the cell membrane, and are widely used in the rapid propagation, transgenic breeding, and somatic hybridization of plants. However, to regenerate the cell wall is a precondition for cell division. Therefore, to study the culture condition and influencing factors during the cell wall regeneration of protoplasts is vital. Traditionally, culture medium is used to cultivate protoplasts, but it has some disadvantages. Herein, a microfluidic system with crossed channels was constructed to isolate and cultivate the protoplasts of tobacco. Then, the cell wall regeneration of the tobacco protoplasts was also studied based on this microfluidic system. It was found that, compared with the control, benzo-(1, 2, 3)-thiadiazole-7-carbothioic acid S-methyl ester (BTH) could accelerate the regeneration of the c... [more]
The Dynamic Shift of Bacterial Communities in Hybrid Anaerobic Baffled Reactor (ABR)—Aerobic Granules Process for Berberine Pharmaceutical Wastewater Treatment
Yan Wang, Yongqiang Liu, Juan Li, Ruirui Ma, Ping Zeng, Choon Aun Ng, Fenghua Liu
February 21, 2023 (v1)
Keywords: 16S rDNA clone library, aerobic granular reactor, anaerobic baffled reactor (ABR), bacterial community structure, berberine wastewater
Because of its anticancer, anti-inflammatory, and antibiotic properties, berberine has been used extensively in medication. The extensive production of berberine results in the generation of wastewater containing concentrated residual berberine. However, to date, limited related studies on the biological treatment of berberine wastewaters have been carried out. A lab-scale anaerobic baffled reactor (ABR)−aerobic granular sludge (AGS) process was developed for berberine removal from synthetic wastewater. The system showed effective removal of the berberine. In order to better understand the roles of the bacterial community, the ABR−aerobic granular sludge system was operated in the state with the highest BBR removal rate in this study. The bacterial community dynamics were studied using the 16S rDNA clone library. The results showed that the hybrid ABR-AGS process achieved 92.2% and 94.8% overall removals of berberine and COD, respectively. Bacterium was dominant species in ABR, while t... [more]
Hybrid TDOA/AOA Hypocenter Localization Using the Constrained Least Squares Method with Deep Learning P-Onset Picking
Hyeongki Ahn, Hyunchang Kim, Ahyeong Choi, Kwanho You
February 21, 2023 (v1)
Keywords: angle of arrival, constrained least squares, deep learning, hypocenter localization, time difference of arrival
In this study, we propose a hypocenter localization algorithm that uses the time difference of arrival (TDOA) and angle of arrival (AOA) as a hybrid model. The hypocenter measurements are detected by the accelerator sensors of the four separate observatories that are closest to the origin of an earthquake. The measurements are calibrated by the proposed deep learning P-onset picking system with short-time Fourier transform (STFT) signal analysis because the accurate detection of Primary waves (P-waves) is limited by seismic environmental noise. The revised measurements are used to calculate the precise distances between the observatories and hypocenters. The proposed hybrid TDOA/AOA is represented by a linear matrix equation that includes the unknowns of the precise distances, coordinates, and arrival angles to the observatories. We estimate a hypocenter using the constrained least squares method (CLS) under the constraints of the TDOA/AOA. The objective function with the constraints i... [more]
Investigating the Possibilities for Simulation of the Interconnected Electric Power and Communication Infrastructures
Matej Vrtal, Jan Benedikt, Radek Fujdiak, David Topolanek, Petr Toman, Jiri Misurec
February 21, 2023 (v1)
Keywords: data network, Optimization, power grid, power outage, Simulation, smart city, smart grid, virtualization
In recent years, we have seen an increasing dependency between different urban critical infrastructures, which raises the demands on their analysis and cybersecurity. Current open-source solutions do not provide simulations of interconnected data networks and power grids, which are essential for analysing of both infrastructures weak parts and reducing the risk of emerging threats. The main purpose of this paper is to describe the design of a simulation platform that provides this type of simulation to customers using the virtual user interface. The paper describes the development of a complex model of interconnected power and data infrastructures. Created virtualization platform that consists of several open-source tools is described in detail. Outputs of this paper can be used for analysis of critical infrastructures at the level of urban networks.
Removal Efficiency of Heavy Metals Such as Lead and Cadmium by Different Substrates in Constructed Wetlands
Guangyi Fu, Shuang Zhou, Yuanyuan Zhao, Zhihui Li, Youze Xu, Zhaohui Guo
February 21, 2023 (v1)
Keywords: cadmium, constructed wetlands, lead, mine wastewater, unburned ceramsite, water treatment residuals
In order to find an efficient and economical wetland substrate to treat mine wastewater containing various heavy metals, and effectively realize the resource utilization of water treatment residuals, in this paper, the treatment efficiency of mine wastewater containing various heavy metals was investigated using unburned ceramsite prepared from water treatment residuals (UCWTR) and clay ceramsite. The continuous dynamic test results showed that the removal rate of Pb, Cd, Cu, Zn, and Fe can reach more than 98.5% after the UCWTR-based CWs runs for 56 days, and its concentration was 30.05%, 24.85%, 20.82%, 14.63%, and 7.91% lower than that of the clay ceramsite-based CWs, respectively. SEM, XPS, and FT-IR showed that the characteristic peaks of two ceramsites were basically similar. The ceramsite undergoes ion exchange, coordination complexation, and chelation reaction with Pb, Cd, Cu, Zn, and Fe under the action of the gel of internal groups -OH, C=O, Al-OH, Si-Fe-O and C-S-H. Compared... [more]
Study on the Grayscale Characteristics of Borehole Images of Progressive Failure of Coal Bodies with Different Moisture Contents
Hongyu Pan, Bing Ji, Xiang Ji, Lei Zhang, Kang Wang, Haotian Wang, Tianjun Zhang
February 21, 2023 (v1)
Keywords: deformation failure, gas extraction, grayscale feature, grayscale image, moisture content, progressive failure
The failure process of a coal body around a borehole has progressive characteristics. Image characteristics can visually characterize the stress and failure characteristics of the coal body around a borehole during progressive failure. To investigate the effect of the moisture content on the progressive failure of the coal body around the borehole, an image test system for the deformation and fracture of coal rock was used, and progressive failure tests of coal body specimens with different moisture content conditions around boreholes were performed. We acquired images of the deformation field during the entire process of specimen failure. Based on the grayscale image theory, the variation in the grayscale characteristic parameters of the progressive failure process was analyzed. The results show that throughout the progressive failure of coal bodies with different moisture contents around a borehole, the main specimen failure can be divided into six stages: compression density, elasti... [more]
Remaining Useful Life Prediction of Gear Pump Based on Deep Sparse Autoencoders and Multilayer Bidirectional Long−Short−Term Memory Network
Peiyao Zhang, Wanlu Jiang, Xiaodong Shi, Shuqing Zhang
February 21, 2023 (v1)
Keywords: deep sparse autoencoder, gear pump, multilayer bidirectional long–short–term memory network, remaining useful life, support vector data description
Prediction of remaining useful life is crucial for mechanical equipment operation and maintenance. It ensures safe equipment operation, reduces maintenance costs and economic losses, and promotes development. Most of the remaining useful life prediction studies focus on bearings, gearboxes, and engines; however, research on hydraulic pumps remains limited. This study focuses on gear pumps that are commonly used in the hydraulic field and develops a practical method of predicting remaining useful life. The deep sparse autoencoder is used to extract multi−dimensional features. Subsequently, the feature vectors are inputted to the support vector data description to calculate the machine degradation degree at the corresponding time and obtain the health indicator curve of the machine’s life cycle. In building the health state degradation curve, data are processed in an unsupervised manner to avoid the influence of artificial feature selection on the test. The method is validated on the pub... [more]
Production of Trehalose from Maltose by Whole Cells of Permeabilized Recombinant Corynebacterium glutamicum
Zaiwei Man, Huihui Cui, Jin Li, Zhiqiang Cai, Jing Guo
February 21, 2023 (v1)
Keywords: constitutive overexpression, Corynebacterium glutamicum, permeabilization, trehalose, trehalose synthase
Trehalose (α-D-glucopyranosyl-1,1-α-D-glucopyranoside) is a stable and nonreducing disaccharide; can be used as sweetener, stabilizer, and humectant; and has many applications in the food, pharmaceutical, and cosmetic industries. Trehalose production from maltose catalyzed by trehalose synthase (TreS) is simple and economically feasible for industrial-scale application. Reducing the cost and enhancing the efficiency of TreS synthesis and the conversion of maltose to trehalose is critical for trehalose production. In this study, the homologous TreS was constitutively overexpressed in Corynebacterium glutamicum ATCC13032 by removing the repressor gene lacIq fragment in the plasmid, and TreS expression could be exempt from the inducer addition and induction process. For cell permeabilization, Triton X-100 was used as a permeabilization agent, and the treatment time was 3 h. In the conversion system, the permeabilized cells of recombinant C. glutamicum were used as biocatalysts, 300 g/L ma... [more]
UPLC Technique in Pharmacy—An Important Tool of the Modern Analyst
Paweł Gumułka, Joanna Żandarek, Monika Dąbrowska, Małgorzata Starek
February 21, 2023 (v1)
Subject: Biosystems
Keywords: analysis of bioactive compounds, drug analysis, pharmaceutical preparations, quality control, separation techniques, UPLC
In recent years, ultra-efficient liquid chromatography (UPLC) has gained particular popularity due to the possibility of faster separation of small molecules. This technique, used to separate the ingredients present in multi-component mixtures, has found application in many fields, such as chemistry, pharmacy, food, and biochemistry. It is an important tool in both research and production. UPLC created new possibilities for analytical separation without reducing the quality of the obtained results. This technique is therefore a milestone in liquid chromatography. Thanks to the increased resolution, new analytical procedures, in many cases, based on existing methods, are being developed, eliminating the need for re-analysis. Researchers are trying to modify and transfer the analytical conditions from the commonly used HPLC method to UPLC. This topic may be of strategic importance in the analysis of medicinal substances. The information contained in this manuscript indicates the importan... [more]
Research on the Optimization Method of Safety Input Structure in Coal Mine Enterprise
Xiu-Zhi Shi, Jin-Yun Zhu, Shu Zhang
February 21, 2023 (v1)
Subject: Optimization
Keywords: Cobb-Douglas production function, comprehensive empowerment, safety input, safety input structure, structure optimization
In order to study the application of the Cobb-Douglas production function on the optimization of safety inputs and further reduce accident losses, two safety input structures of a coal mine enterprise were constructed using literature, and the weight order of each safety input indicator was determined by the entropy weight method (EWM) and the analytical hierarchy process (AHP). The Cobb-Douglas production function was used to calculate the accident loss function of the safety input structure, and the accident loss function was obtained by multiple regression analysis. The optimal configuration of safety inputs was obtained by fitting the accident loss function. Finally, the optimal loss and mean squared error (MSE) of the corresponding functions of the two safety input structures were compared. The results show that the optimal configuration of Safety Input Structure 2 is better than that of Safety Input Structure 1, and the MSE of Safety Input Structure 2 is less than that of Safety... [more]
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