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Showing records 11295 to 11319 of 43611. [First] Page: 1 449 450 451 452 453 454 455 456 457 Last
Phase Equilibria Simulation of Biomaterial-Hydrogen Binary Systems Using a Simple Empirical Correlation
Fardad Faress, Afham Pourahmad, Seyyed Amirreza Abdollahi, Mohammad Hossein Safari, Mozhgan Mozhdeh, Falah Alobaid, Babak Aghel
April 11, 2023 (v1)
Subject: Materials
Keywords: artificial neural networks, biochemical–hydrogen binary system, comparative analyses, empirical correlation, equations of state
This study proposes a simple correlation for approximating hydrogen solubility in biomaterials as a function of pressure and temperature. The pre-exponential term of the proposed model linearly relates to the pressure, whereas the exponential term is merely a function of temperature. The differential evolution (DE) optimization algorithm helps adjust three unknown coefficients of the correlation. The proposed model estimates 134 literature data points for the hydrogen solubility in biomaterials with an excellent absolute average relative deviation (AARD) of 3.02% and a coefficient of determination (R) of 0.99815. Comparing analysis justifies that the developed correlation has higher accuracy than the multilayer perceptron artificial neural network (MLP-ANN) with the same number of adjustable parameters. Comparing analysis justifies that the Arrhenius-type correlation not only needs lower computational effort, it also has higher accuracy than the PR (Peng-Robinson), PC-SAFT (perturbed-c... [more]
Supply Chain Management during a Public Health Emergency of International Concern: A Bibliometric and Content Analysis
Jianli Luo, Minmin Huang, Yanhu Bai, Jia Li
April 11, 2023 (v1)
Keywords: disruption recovery, disruption risk, response to epidemic, supply chain strategy, sustainable supply chain management
A public health emergency of international concern, such as a pandemic, disrupts the normal operation of the global supply chain, which necessitates in-depth research on supply chain management. In this paper, we used bibliometric and content analysis to provide a systematic analysis of the supply chain industry from this background. The descriptive analysis provides insights into the publication growth trajectory, in terms of the contributing authors, countries, and subject categories, which presents an intuitive display of previous research. In addition, the existing research mainly covers three dimensions of supply chain disruption, strategies, and sustainability, which can be clustered into supply chain disruption, disruption recovery, reconfiguration, digital intelligence, optimization, and sustainability. By revisiting the supply chain industry, we explored the transformation of its characteristics in the pandemic, covering themes ranging from expansion to contraction, from tradi... [more]
Procainamide Charge Transfer Complexes with Chloranilic Acid and 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone: Experimental and Theoretical Study
A. F. M. Motiur Rahman, Ahmed H. Bakheit, Shofiur Rahman, Gamal A. E. Mostafa, Haitham Alrabiah
April 11, 2023 (v1)
Subject: Biosystems
Keywords: charge transfer complex, chloranilic acid, DDQ, DFT, procainamide
The formation of charge transfer (CT) complexes between bioactive molecules and/or organic molecules is an important aspect in order to understand ‘molecule-receptor’ interactions. Here, we have synthesized two new CT complexes, procainamide-chloranilic acid (PA-ChA) and procainamide-2,3-dichloro-5,6-dicyano-1,4-benzoquinone (PA-DDQ), from electron donor procainamide (PA), electron acceptor chloranilic acid (ChA), and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The structures of these two CT complexes were elucidated/characterized using FTIR, NMR, and many other spectroscopic methods. A stability study of each complex was conducted for the first time using various spectroscopic parameters (e.g., formation constant, molar extinction coefficient, ionization potential oscillator strength, dipole moment, and standard free energy). The formation of CT complexes in solution was confirmed by spectrophotometric determination. The molecular composition of each complex was determined using... [more]
Connecting Fiscal Decentralization with Climate Change Mitigation in China: Directions for Carbon Capturing Systems
Tao Deng, Mohammed Arshad Khan, Moin Uddin, Ahsanuddin Haider
April 11, 2023 (v1)
Keywords: Carbon Capture, carbon emission, China, climate change mitigation, fiscal decentralization
The research aims to assess the relationship between fiscal decentralization and climate change mitigation to warrant the direction for the carbon-capturing systems of China. The study estimated the results of China and applied unit root test, cointegration analysis, CS-ARDL test, and robustness analysis. The survey results highlighted a significant relationship between the fiscal decentralization index and climate change mitigation. More specifically, the budgetary decentralization index’s economic, governmental, and institutional factors play a substantial role in climate change mitigation in the short run. While governmental factors are found insignificant asein the long run, economic, institutional, and cultural factors revealed a significant connection in the Chinese setting. The results of the study are robust in both long-run and short-run perspectives. The study also presented prudential guidelines for using fiscal decentralization as an environmental tool for climate change mi... [more]
Automotive Supply Chain Disruption Risk Management: A Visualization Analysis Based on Bibliometric
Kai Huang, Jian Wang, Jinxin Zhang
April 11, 2023 (v1)
Keywords: automotive supply chain disruption, bibliometric analysis, co-citation analysis, disruption risk, supply chain resilience
The automobile industry is the pillar industry of the national economy. The good operation of the automobile supply chain is conducive to the sustainable development of the economy and social economy. In recent years, the popular research of automotive supply chain disruption risk management has been widely of concern by both business and academic practitioners. It is observed that most of the literature has focused only on a particular journal or field; there is a distinct lack of comprehensive bibliometric review of two decades, of research on automotive supply chain disruption risk management. This paper delivers a comprehensive bibliometric analysis that provides a better understanding not previously fully evaluated by earlier studies in the field of automotive supply chain disruption risk management. We used the 866 journal article during the period between 2000 and 2022 from the WOS database as sample data. Highlights research topics and trends, key features, developments, and po... [more]
Bilateral Matching Decision Making of Partners of Manufacturing Enterprises Based on BMIHFIBPT Integration Methods: Evaluation Criteria of Organizational Quality-Specific Immunity
Qiang Liu, Hongyu Sun, Yao He
April 11, 2023 (v1)
Keywords: bidirectional projection technology, bilateral matching decision making, interval-valued hesitant fuzzy information, organizational quality-specific immunity
This study aims to examine how the bilateral matching decision making of manufacturing enterprises that are seeking partners in the manufacturing supply chain can be improved by taking into consideration evaluation criteria for organizational quality-specific immunity. This study constructs an evaluation indicator system to measure organizational quality-specific immunity based on immune theory. The system’s evaluation criteria are based on the key components of organizational quality-specific immunity. We also construct bilateral matching evaluation and decision-making models using interval-valued hesitant fuzzy information and bidirectional projection technology (BMIHFIBPT). The interval-valued bilateral fuzzy bidirectional projection technology is applied to solve a combination satisfaction and matching optimization model. Empirical analysis is carried out to assess both the supply and demand sides of representative manufacturing enterprises in the manufacturing supply chain, match... [more]
Kinetic Analysis of Pyrolysis Reaction of Hydrogen-Containing Low Rank Coals Based on Thermogravimetric Method
Qiyuan Mi, Bin Li, Yifan Li, Yue Ma, Ruimeng Shi
April 11, 2023 (v1)
Keywords: DAEM model, low rank coal, pyrolysis kinetics, volatiles
Based on the combined technology of thermogravimetric analysis-mass spectrometry (TG-MS), the non isothermal kinetic of two low rank coals with high hydrogen content and the release characteristics of H2 in volatiles were explored. The effect of coal species and coal particle size on pyrolysis was studied. The CR (Coats-Redfern) method and the DAEM (Distributed activation energy model) method were used to construct the pyrolysis kinetic model by dividing temperature stages, and the results showed that the mechanisms of pyrolysis process of lower rank coals were mainly 3-D diffusion (G-B) and Growth of nucleation (Avrami-Erofeev, n = 1/3). The use of the DAEM method made up for the shortcomings of the CR method in calculating the activation energy, and the analysis of coal pyrolysis kinetics was more comprehensive. The higher the volatile content the coal contained, the lower activation energy the pyrolysis process would require. The larger the particle size of the coal was, the higher... [more]
Temperature and Thermal Stress Analysis of a Hot Blast Stove with an Internal Combustion Chamber
Donghwi Park, Feng Guo, Jongrak Choi, Joo-Hyoung Park, Naksoo Kim
April 11, 2023 (v1)
Keywords: Computational Fluid Dynamics, finite element analysis, hot blast stove, thermal stress
In this study, the temperature and thermal stress fields of an internal combustion hot blast stove were calculated and analysed. Turbulent, species transport, chemical reaction, radiation, and porous media models were implemented in a computational fluid dynamics model. Thermal boundary conditions on the structure of the hot blast stove were calculated based on the analytic adiabatic Y-plus method. A method to interpolate the thermal boundary conditions to a finite element mesh was developed, and the boundary conditions were mapped through the proposed method. In the on-gas period, the vortex was generated in the dome, and it made the variation of the temperature field in the checker chamber. The maximum temperature of the flue gas reached 1841 K in the on-gas period. In the on-blast period, the flow was considerably even compared to the on-gas period, and the average blast temperature reached 1345 K. The outer region of the checker chamber is shown to be continuously exposed to a high... [more]
Review of Emission Characteristics and Purification Methods of Volatile Organic Compounds (VOCs) in Cooking Oil Fume
Chong Tao, Limo He, Xuechen Zhou, Hanjian Li, Qiangqiang Ren, Hengda Han, Song Hu, Sheng Su, Yi Wang, Jun Xiang
April 11, 2023 (v1)
Subject: Environment
Keywords: catalytic combustion, cooking oil fume, emission characteristics, purification methods, VOCs
Volatile organic compounds (VOCs) in cooking oil fumes need to be efficiently removed due to the significant damage they cause to the environment and human health. This review discusses the emission characteristics, which are influenced by different cooking temperatures, cooking oils, and cuisines. Then, various cooking oil fume purification methods are mainly classified into physical capture, chemical decomposition, and combination methods. VOCs removal rate, system operability, secondary pollution, application area, and cost are compared. The catalytic combustion method was found to have the advantages of high VOC removal efficiency, environmental protection, and low cost. Therefore, the last part of this review focuses on the research progress of the catalytic combustion method and summarizes its mechanisms and catalysts. The Marse-van Krevelen (MVK), Langmuir-Hinshelwood (L-H), and Eley-Rideal (E-R) mechanisms are analyzed. Noble metal and non-noble metal catalysts are commonly use... [more]
County-Based PM2.5 Concentrations’ Prediction and Its Relationship with Urban Landscape Pattern
Lijuan Yang, Shuai Wang, Xiujuan Hu, Tingting Shi
April 11, 2023 (v1)
Subject: Environment
Keywords: landscape pattern, PM2.5, random forest, YRD-FJ
Satellite top-of-atmosphere (TOA) reflectance has been validated as an effective index for estimating PM2.5 concentrations due to its high spatial coverage and relatively high spatial resolution (i.e., 1 km). For this paper, we developed an emsembled random forest (RF) model incorporating satellite top-of-atmosphere (TOA) reflectance with four categories of supplemental parameters to derive the PM2.5 concentrations in the region of the Yangtze River Delta-Fujian (i.e., YRD-FJ) located in east China. The landscape pattern indices at two levels (i.e., type level and overall level) retrieved from 3-year land classification imageries (i.e., 2016, 2018, and 2020) were used to discuss the correlation between county-based PM2.5 values and landscape pattern. We achieved a cross validation R2 of 0.91 (RMSE = 9.06 μg/m3), 0.89 (RMSE = 10.19 μg/m3), and 0.90 (RMSE = 8.02 μg/m3) between the estimated and observed PM2.5 concentrations in 2016, 2018, and 2020, respectively. The PM2.5 distribution re... [more]
Efficacious Utilization of Food Waste for Bioenergy Generation through the Anaerobic Digestion Method
Preethi Muthu, Gunasekaran Muniappan, Rajesh Banu Jeyakumar
April 11, 2023 (v1)
Keywords: biofuel, exploitation, hydrolysis, substrate, valorization
Energy fuels retrieved from biomass utilization are considered to be an economically and environmentally friendly source. In this day and age, bioenergy provides an alternative option to replace traditional fossil-based energy to accomplish energy demand with fewer greenhouse gas emissions into the environment. A huge amount of food waste is produced every year due to mass ethnographic activities. Their potential has been underused and this has led to waste ending up in the garbage. Bioenergy production by anaerobic digestion of cheap substrate provides an effectual approach to cope with this issue. The hydrolysis stage during anaerobic digestion is enhanced by various pretreatment methods, where the disintegration of the waste substrate leads to the enhancement of soluble organics and eases the production of bioenergy. The present review focuses on state-of-the-art knowledge about food waste, its utilization, and its valorization by the action of pretreatment, thereby enhancing anaero... [more]
A Fault-Tolerant and Reconfigurable Control Framework: Modeling, Design, and Synthesis
Imane Tahiri, Alexandre Philippot, Véronique Carré-Ménétrier, Bernard Riera
April 11, 2023 (v1)
Keywords: control reconfiguration, discrete event systems, distributed control, fault tolerant control, manufacturing systems
Manufacturing systems (MS) have become increasingly complex due to constraints induced by a changing environment, such as flexibility, availability, competition, and key performance indicators. This change has led to a need for flexible systems capable of adapting to production changes while meeting productivity and quality criteria and reducing the risk of failures. This paper provides a methodology for designing reconfigurable and fault-tolerant control for implementation in a Programmable Logic Controller (PLC). The main contribution of this methodology is based on a safe control synthesis founded on timed properties. If a sensor fault is detected, the controller switches from normal behavior to a degraded one, where timed information replaces the information lost from the faulty sensor. Switching between normal and degraded behaviors is ensured through reconfiguration rules. The primary objective of this method is to implement the obtained control into a PLC. In order to achieve th... [more]
Drying Kinetics, Physicochemical and Thermal Analysis of Onion Puree Dried Using a Refractance Window Dryer
Ruchika Zalpouri, Manpreet Singh, Preetinder Kaur, Amrit Kaur, Kirtiraj K. Gaikwad, Ashutosh Singh
April 11, 2023 (v1)
Keywords: artificial neural network, convective drying, Modelling, onion puree, quality, refractance window drying
Onions have a high moisture content, which makes them more susceptible to microbial growth. Drying is one of the postharvest preservation methods applied to decrease onion moisture content, thereby increasing its storage life. In this study, onions were peeled, washed, cut into quarters, hot water blanched, and pureed. The puree was further dried using two different drying methods: refractance window drying (RWD) (water temperature: 70 °C) and convective drying (CD) (50 °C). The puree was spread on prefabricated trays at varying thicknesses of 2 mm, 4 mm, and 6 mm. It was observed that, irrespective of the drying method, moisture ratio (MR) decreased and drying time and effective moisture diffusivity increased with respect to the thickness of the puree. In addition, the Lewis model and the Wang and Singh model showed the highest R2 and lowest SEE value for RWD and CD, respectively. Moreover, the MR of onion puree during RWD and CD was predicted using a multi-layer feed-forward (MLF) ar... [more]
Recent Access to Polycycles via Post-Ugi Reactions
Xiao Tang, Liangliang Song
April 11, 2023 (v1)
Subject: Materials
Keywords: polycycle, post-Ugi cyclization, Ugi reaction
Ugi reactions have been widely studied due to their mild reaction conditions, high structural variability, and wide applications. Ugi adducts have proved to be highly efficient for different kinds of post-transformations by carefully choosing the starting four components. Considering the importance of polycycles, diverse post-Ugi transformations have been employed for the construction of structurally novel polycyclic N-heterocycles. This minireview summarizes the recent developments of post-Ugi reactions for the synthesis of polycycles after the year 2019. Through transition metal catalysis from gold, rhodium, silver, copper, and palladium, as well as transition metal-free approaches, versatile polycycles are constructed in a highly efficient and step-economical manner.
Supervision and Control System of the Operational Variables of a Cluster in a High-Pressure Gas Injection Plant
Cristhian Ronceros, José Medina, Juan Vásquez, Pedro León, José Fernández, Estefany Urday
April 11, 2023 (v1)
Keywords: cluster, control, gas injection, high pressure, remote terminal, supervision
The objective of this research was to develop a technological architecture proposal that allows for the supervision and control of the operational parameters of gas injection (flow, temperature, and pressure) in a cluster of a high-pressure gas injection plant. The proposal provides a supervision and control system for the HPGIP I high-pressure gas injection plant that includes instrumentation equipment (transmitters and actuators), a remote terminal unit (RTU) as a control device, and the creation of a control logic as the basis for the development of the SCADA GALBA®, through which the operational variables involved in the process of the gas injection plant can be visualized and controlled, allowing the automatic regulation of the flow of gas that enters the deposits. Automatization of the process allows for the elimination of the average error differential that increases from 2 to 5% when the control valve is opened manually. Currently, the MUC-67 and MUC-68 wells that make up clust... [more]
Digital-Rock Construction of Shale Oil Reservoir and Microscopic Flow Behavior Characterization
Jianguang Wei, Jiangtao Li, Ying Yang, Ao Zhang, Anlun Wang, Xiaofeng Zhou, Quanshu Zeng, Demiao Shang
April 11, 2023 (v1)
Subject: Materials
Keywords: continental shale reservoir, digital core, flow characteristics, lattice Boltzmann method, micro-nano scale
In shale oil reservoirs, nano-scale pores and micro-scale fractures serve as the primary fluid storage and migration space, while the associated flow mechanism remains vague and is hard to understand. In this research, a three-dimensional (3D) reconstruction of the shale core and micro-pore structure description technique is established; digital core technology for shale reservoirs was developed using X-ray computed tomography (X-CT), scanning electron microscope (SEM) and a focused ion beam scanning electron microscope (FIB-SEM). Microscopic oil−water two-phase flow is mimicked using the lattice Boltzmann method (LBM), a well-acknowledged approach to exploring nanoconfined fluid dynamics. In addition, coupled with digital cores, the flow characteristics of shale reservoirs are characterized. The total porosities of bedding fractures in shale and lamellar shale are 2.042% and 1.085%, respectively. The single-phase oil flow inside bedding fractures follows Darcy’s linear flow principle.... [more]
Evaluation of Technical Feasibility of Solar Heat Integration in Agri-Food Industries
Julio Guillen-Angel, Ignacio Julian
April 11, 2023 (v1)
Keywords: industrial heating, PCM, renewables, solar heating, solar share, Solar Thermal
This work assesses the use of different solar heating integration configurations and heating storage solutions for three different agri-food industries located in southern Europe. TRNSYS is employed to model different Solar Heat for Industrial Process (SHIP) integration options and to quantify the solar thermal share with respect to the overall thermal demand, as well as to estimate the avoided consumption of fuels and CO2 emissions in the existing boiler units as a result of the solar system integration. The SHIP integration is complemented with the evaluation of selected phase-change materials (PCM) to promote latent heat storage under the specific conditions of the considered agri-food demo sites and solar irradiation characteristics. The arrangement of flat-plate solar collectors coupled with latent heat storage was found to enhance the yearly averaged solar share of the SHIP solutions, reaching 13% of the overall thermal demand for an average Spanish winery demo site. Furthermore,... [more]
Novel Iterative Feedback Tuning Method Based on Overshoot and Settling Time with Fuzzy Logic
Jacob Gonzalez-Villagomez, Carlos Rodriguez-Donate, Misael Lopez-Ramirez, Ruth I. Mata-Chavez, Omar Palillero-Sandoval
April 11, 2023 (v1)
Keywords: fuzzy logic, overshoot, PID controller tuning, settling time
Proportional−integral−derivative controllers are applied for solving a wide range of problems in industrial processes. They are preferred over computational techniques because of their implementation simplicity, low cost, and robustness against noise. In this paper, a novel iterative feedback tuning method is proposed using fuzzy logic, where the design parameters proposed by the user are the desired plant overshoot and settling time. In contrast to classical methods, the proposed technique does not require a precise and complex mathematical model for tuning the proportional−integral−derivative controllers through the plant, nor does it need an expert who knows the precise behavior of the system as in methods based on computational techniques. Furthermore, unlike iterative feedback tuning methods that use cost functions and require several experiments to perform the iterations, this proposal uses fuzzy logic to update the controller parameters, which facilitates its implementation in p... [more]
A Casing Deformation Prediction Model Considering the Properties of Cement
Bo Zeng, Xiaojin Zhou, Jing Cao, Feng Zhou, Yao Wang, Yezhong Wang, Yi Song, Junjie Hu, Yurou Du
April 11, 2023 (v1)
Keywords: analytic model, casing deformation, cement sheath, minimum drift diameter
A large amount of casing deformation has occurred in shale gas wells during the complex fracturing process, which affects the fracturing construction and single well production. Based on the statistical analysis of casing deformation wells and caliper logging interpretation, the main mechanism of casing deformation of shale gas wells is revealed as formation slip. By comprehensively considering the rotating speed under casing running condition, the cement solidification heat release under cementing condition, and the fracturing fluid temperature drop under fracturing condition, the safe service margin of the casing is large. Moreover, simply increasing the casing steel grade and wall thickness has no obvious effect on casing deformation prevention, so full wellbore casing deformation prevention measures should be considered. By using the method of unconventional oil and gas well casing string simulation test and numerical simulation, the mechanical response of wellbore and the mechanis... [more]
Evolutionary Process for Engineering Optimization in Manufacturing Applications: Fine Brushworks of Single-Objective to Multi-Objective/Many-Objective Optimization
Wendi Xu, Xianpeng Wang, Qingxin Guo, Xiangman Song, Ren Zhao, Guodong Zhao, Yang Yang, Te Xu, Dakuo He
April 11, 2023 (v1)
Keywords: carbon neutrality, engineering optimization, evolutionary process, manufacturing applications, system optimization, transfer learning
Single-objective to multi-objective/many-objective optimization (SMO) is a new paradigm in the evolutionary transfer optimization (ETO), since there are only “1 + 4” pioneering works on SMOs so far, that is, “1” is continuous and is firstly performed by Professors L. Feng and H.D. Wang, and “4” are firstly proposed by our group for discrete cases. As a new computational paradigm, theoretical insights into SMOs are relatively rare now. Therefore, we present a proposal on the fine brushworks of SMOs for theoretical advances here, which is based on a case study of a permutation flow shop scheduling problem (PFSP) in manufacturing systems via lenses of building blocks, transferring gaps, auxiliary task and asynchronous rhythms. The empirical studies on well-studied benchmarks enrich the rough strokes of SMOs and guide future designs and practices in ETO based manufacturing scheduling, and even ETO based evolutionary processes for engineering optimization in other cases.
Structural Optimization of High-Pressure Polyethylene Cyclone Separator Based on Energy Efficiency Parameters
Baisong Hu, Shuo Liu, Chuanzhi Wang, Bingjun Gao
April 11, 2023 (v1)
Keywords: Computational Fluid Dynamics, cyclone separator, design of experiment, high-pressure polyethylene, pressure drop, separation efficiency
The high-pressure polyethylene process uses cyclone separators to separate ethylene gas, polyethylene, and its oligomers. The oligomers larger than 10 microns that cannot be separated must be filtered through a filter to prevent them from entering the compressor and affecting its normal operation. When the separation efficiency of the cyclone separator is low, the filter must be cleaned more frequently, which will reduce production efficiency. Research shows that improving the separation efficiency of the separator is beneficial for the separation of small-particle oligomers and reduces the frequency of filter cleaning. For this reason, Computational Fluid Dynamics simulations were performed for 27 sets of cyclone separators to determine the effects of eight structural factors (cylinder diameter, cylinder height, cone diameter, cone height, guide vane height, guide vane angle, exhaust pipe extension length, and umbrella structure height) on separation efficiency and pressure drop. The... [more]
Scalindua, a Biological Solution to Treat Saline Recirculating Aquaculture System Wastewater
Federico Micolucci, Jonathan A. C. Roques, Geoffrey S. Ziccardi, Naoki Fujii, Kristina Sundell, Tomonori Kindaichi
April 11, 2023 (v1)
Subject: Environment
Keywords: “Candidatus Scalindua”, anaerobic ammonium oxidation (anammox), recirculating aquaculture system (RAS), trace elements, wastewater treatment
Recirculating aquaculture systems (RAS) are promising candidates for the sustainable development of the aquaculture industry. A current limitation of RAS is the production and potential accumulation of nitrogenous wastes, ammonium (NH4+), nitrite (NO2−) and nitrate (NO3−), which could affect fish health and welfare. In a previous experiment, we have demonstrated that the marine anammox bacteria Candidatus Scalindua was a promising candidate to treat the wastewater (WW) of marine, cold-water RAS. However, the activity of the bacteria was negatively impacted after a direct exposure to RAS WW. In the current study, we have further investigated the potential of Ca. Scalindua to treat marine RAS WW in a three-phase experiment. In the first phase (control, 83 days), Ca. Scalindua was fed a synthetic feed, enriched in NH4+, NO2− and trace element (TE) mix. Removal rates of 98.9% and 99.6% for NH4+ and NO2−, respectively, were achieved. In the second phase (116 days), we gradually increased th... [more]
Genesis Types and Migration of Middle and Lower Assemblages of Natural Gas in the Eastern Belt around the Penyijingxi Sag of the Junggar Basin, NW China
Keshun Liu, Jiangxiu Qu, Ming Zha, Hailei Liu, Xiujian Ding, Minghui Zhou, Tianze Gao
April 11, 2023 (v1)
Keywords: carbon isotopes, Junggar Basin, light hydrocarbons, migration characteristics, natural gas genesis
This study analyzes the geochemical characteristics of natural gas composition, carbon isotope, and light hydrocarbon in the eastern belt around the Penyijingxi sag of the Junggar Basin. The result shows the that natural gas content is dominated by alkane gas, with low contents of heavy hydrocarbon and non-hydrocarbon components. The overall carbon isotopic composition of the alkanes shows a trend as δ13methane (C1) < δ13ethane (C2) < δ13propane (C3) < δ13butane (C4), and all δ13C1 values are <−30‱, which are typical of gases of organic origin. The natural gas is mainly coal-derived gas from the Lower Urho formation, mixed with a small amount of oil-associated gas from the Fengcheng formation. The vertical migration of natural gas resulted in the mixing of oil-associated gas and coal-derived gas and the mixing of alkane gas at different stages of the same origin, which should be the origin of carbon isotope inversion. The diffusion migration of carboniferous oil and gas res... [more]
Lactic Acid: A Comprehensive Review of Production to Purification
Abidemi Oluranti Ojo, Olga de Smidt
April 11, 2023 (v1)
Subject: Biosystems
Keywords: Fermentation, lactic acid, lignocellulose, microorganisms, pretreatments
Lactic acid (LA) has broad applications in the food, chemical, pharmaceutical, and cosmetics industries. LA production demand rises due to the increasing demand for polylactic acid since LA is a precursor for polylactic acid production. Fermentative LA production using renewable resources, such as lignocellulosic materials, reduces greenhouse gas emissions and offers a cheaper alternative feedstock than refined sugars. Suitable pretreatment methods must be selected to minimize LA cost production, as the successful hydrolysis of lignocellulose results in sugar-rich feedstocks for fermentation. This review broadly focused on fermentative LA production from lignocellulose. Aspects discussed include (i). low-cost materials for fermentative LA production, (ii). pretreatment methods, (iii). enzymatic hydrolysis of cellulose and hemicellulose, (iv). lactic acid-producing microorganisms, including fungi, bacteria, genetically modified microorganisms, and their fermentative pathways, and (v). f... [more]
Fresh Approaches for Structured Text Programmable Logic Controllers Programs Verification
Émile Siboulet, Louen Pottier, Tom Ranger, Bernard Riera
April 11, 2023 (v1)
Keywords: automation, model checking, programmable logic controllers, recurrent neural networks, relational databases, structured text, system verification
Programmable logic controllers (PLCs) are everywhere today and perform critical tasks in industries. They are considered as a key component for the Industry 4.0. Before they are put into operation, it is necessary to check the accuracy of the PLC programs. This verification operation can be performed using model checkers. This stage is often long and costly and requires a domain expert who can understand the system, as well as the different model checker tools able to verify the code implemented in the controller. Furthermore, this verification often requires a conversion of the PLC code into a language understood by a model checker which can influence the behavior of the observed PLC. Hence, there is a need to propose methods and tools which could be used by technicians and engineers. The aim of this paper is to propose methods that require little work to set up and are robust to program sizes used in Industry 4.0. This paper explores some fresh ideas for human-adapted PLC code verifi... [more]
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