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Showing records 101 to 125 of 41325. [First] Page: 1 2 3 4 5 6 7 8 9 Last
Promoting Effect of Microwave Field on Gas Phase Diffusion Limited Magnetite Reduction in Carbon Monoxide
Meijie Zhou, Liqun Ai, Lukuo Hong, Caijiao Sun, Shuai Tong
February 10, 2024 (v1)
Subject: Materials
Keywords: CO reduction, kinetics, magnetite, microstructure characterization, microwave irradiation
To investigate the effect of microwave irradiation on the rate of magnetite reduction while increasing the gas phase diffusion rate limit, the microstructure and kinetics of CO reduction of magnetite powder were studied. The investigation was conducted through microwave irradiation and conventional heating at 900~1100 °C. Under the two heating methods, the iron crystal is selectively reduced and gradually expanded along the direction normal to the length of the ore powder, forming a strip of iron crystal that penetrates the powder and expands outward across the width. The microwave field can effectively improve the sintering of minerals. The changes in Avrami exponents m and k in the reduction process were determined by combining the Johnson−Mehl−Avrami (JMA) model with the lnln method. The microwave field did not change the limiting step. Microwave irradiation proves to be the most effective means to enhance both the initial reduction rate and the rate during the primary iron crystal... [more]
TBM Rapid Tunneling Roadway Support Parameters Design and Process Research
Tao Hou, Zhonghui Xie, Ling Zhang, Guogang Cui, Ziwei Ding, Huafu Qiu, Yuhang Li
February 10, 2024 (v1)
Subject: Other
Keywords: parameter design, rapid tunneling, roadway support scheme, surrounding rock deformation, tunneling process optimization
Taking the specific production geological conditions of the auxiliary transportation lane in the west area of Gaojiabao coal mine of Shaanxi Zhengtong Coal Industry as the research background, based on the anchorage support theory and the characteristics of the TBM digging process, numerical simulation, theoretical analysis, and other research methods were used to investigate the depth of the destruction of the plastic zone of the surrounding rock of the roadway to form the reasonable support parameters of a large cross-section of hard rock roadway suitable for TBM digging and to propose an intelligent digging and support process of the TBM corresponding to the on-site practice. The proposed intelligent tunneling support technology corresponds to a field practice of TBM. The study shows that: combined with the field industrial test and adjusted by the peripheral rock deformation and damage law, the anchor diameter of 20 mm, the length of 2500 mm left-hand threaded steel anchors, row sp... [more]
Security of Cyber-Physical Systems of Chemical Manufacturing Industries Based on Blockchain
Wu Deng, Wei Fan, Zhenzhen Li, Chi Cui, Xu Ji, Ge He
February 10, 2024 (v1)
Keywords: blockchain, chemical industrial manufacturing, cyber-physical system, information security
The traditional manufacturing systems are often enterprise-centric systems, whereas the modern chemical industry is oriented towards industrial chain integration. Enterprise entities present a loosely coupled state at the scale of the industrial chain, with decentralized characteristics. This poses greater challenges and requirements for the industrial safety system. Based on the characteristics of the chemical manufacturing industry and blockchain, the application of the information security of blockchain in the chemical manufacturing industry is studied herein and the cyber-physical systems security architecture model of dual blockchains is proposed. The first-layer blockchain is applied at the system’s core function level to solve security issues at the system level and provide security guarantees for communication, transactions, and billing between users and manufacturers. Meanwhile, the second layer involves the system resource layer, which not only solves the security problem of... [more]
Application of Three-Dimensional Printing Technology to the Manufacture of Petroleum Drill Bits
Baxian Liu, Yifei Wang, Junjie Jiang, Bihui Zhang, Jian Zhou, Kuilin Huang
February 10, 2024 (v1)
Subject: Other
Keywords: 3D printing, machining accuracy, mold forming, petroleum drill bit, rate of penetration
Drill bits are the main rock-breaking tools in the petroleum and gas industry. Their performance directly affects the quality, efficiency, and cost of drilling. Drill bit manufacturing mainly employs traditional mold forming processes such as milling molding and press molding, which have low production efficiency and long processing cycles and are not conducive to rapid responses to field requirements. Inadequate production accuracy makes it difficult to produce drill bits with complex structures. Three-dimensional (3D) printing technology has fast molding speeds and high molding accuracy. In this paper, 3D printing was applied for the first time to the manufacture of molds for carcass polycrystalline diamond compact (PDC) drill bits and PDC−cone hybrid drill bits. In comparison with forging and milling molding, 3D printing improved production efficiency. The manufactured molds had higher machining accuracy. The ability of 3D printing to make molds with complex surfaces enables the dev... [more]
Artificial Intelligence and Carbon Emissions in Manufacturing Firms: The Moderating Role of Green Innovation
Yixuan Chen, Shanyue Jin
February 10, 2024 (v1)
Subject: Environment
Keywords: Artificial Intelligence, carbon emissions, green management innovation, green product innovation, green technology innovation
Carbon emissions have gained worldwide attention in the industrial era. As a key carbon-emitting industry, achieving net-zero carbon emissions in the manufacturing sector is vital to mitigating the negative effects of climate change and achieving sustainable development. The rise of intelligent technologies has driven industrial structural transformations that may help achieve carbon reduction. Artificial intelligence (AI) technology is an important part of digitalization, providing new technological tools and directions for the low carbon development of enterprises. This study selects Chinese A-share listed companies in the manufacturing industry from 2012 to 2021 as the research objects and uses a fixed-effects regression model to study the relationship between AI and carbon emissions. This study clarifies the significance of enterprise AI technology applications in realizing carbon emissions reduction and explores the regulatory mechanism from the perspective of the innovation effec... [more]
An Experimental Investigation on the Shear-Seepage Coupling Failure Behavior of Split Grouting-Reinforced Body
Yaolei Zhang, Haitong Sui, Lei Yang, Rongfeng Lin
February 10, 2024 (v1)
Subject: Environment
Keywords: confining pressure, failure mechanism, seepage pressure, soil–slurry interface, split grouting-reinforced body
A split grouting-reinforced body (SGRB) is the new surrounding rock that forms after split grouting reinforcement in tunnels and underground engineering, and its shear-seepage behavior is one of the critical factors affecting tunnel stability. The effects of seepage pressure, confining pressure, and the roughness of the soil−slurry interface on the shear-seepage characteristics of SGRB specimens were investigated using a modified triaxial shear-seepage coupling test system. The failure mechanism for the SGRB was analyzed taking into account its seepage behavior and mechanical characteristics. The results showed that the seepage process of the SGRB specimens could be divided into four stages according to the seepage velocity, including the waterless, rapid, decelerating, and steady seepage stages, and the corresponding water turbidity in the seepage stages was classified as turbid, mildly turbid, or clear, respectively. The peak shear stress of the soil−slurry interface of the SGRB spec... [more]
Automated Shape and Process Parameter Optimization for Scaling Up Geometrically Non-Similar Bioreactors
Stefan Seidel, Fruhar Mozaffari, Rüdiger W. Maschke, Matthias Kraume, Regine Eibl-Schindler, Dieter Eibl
February 10, 2024 (v1)
Keywords: biochemical engineering, computational fluid dynamics (CFD), energy dissipation rate, HEK293, hydrodynamic stress, Kolmogorov length scale, open-source, Optimization, scale-up
Scaling bioprocesses remains a major challenge. Since it is physically impossible to increase all process parameters equally, a suitable scale-up strategy must be selected for a successful bioprocess. One of the most widely used criteria when scaling up bioprocesses is the specific power input. However, this represents only an average value. This study aims to determine the Kolmogorov length scale distribution by means of computational fluid dynamics (CFD) and to use it as an alternative scale-up criterion for geometrically non-similar bioreactors for the first time. In order to obtain a comparable Kolmogorov length scale distribution, an automated geometry and process parameter optimization was carried out using the open-source tools OpenFOAM and DAKOTA. The Kolmogorov−Smirnov test statistic was used for optimization. A HEK293-F cell expansion (batch mode) from benchtop (Infors Minifors 2 with 4 L working volume) to pilot scale (D-DCU from Sartorius with 30 L working volume) was carri... [more]
Exergy Loss Assessment Method for CNC Milling System Considering the Energy Consumption of the Operator
Zhaohui Feng, Hua Zhang, Wei Li, Yajian Yu, Youjia Guan, Xinru Ding
February 10, 2024 (v1)
Keywords: CNC milling system, exergy analysis, the energy consumption of the operator, the specific exergy loss
Modeling and assessing the sustainability of machining systems has been considered to be a crucial approach to improving the environmental performance of machining processes. As the most common machining system, the computer numerical control (CNC) milling system is a typical man−machine cooperative system where the activities of the machine tool and operator generate material and energy consumption. However, the energy consumption of the operator in the CNC milling system has often been ignored in most existing research. Therefore, existing methods fail to provide a comprehensive understanding of the sustainability of the CNC milling system. To fill this gap, an exergy loss assessment method is proposed to investigate the sustainability of the CNC milling system, where the energy consumption of the operator, the energy consumption of the machine tool, and material consumption are taken into consideration. The key performance indexes of the energy consumption of the operator, the energ... [more]
Acetylcellulose Recovery from Waste Residual for Attenuating Reactive Dye from Aquaculture Waste as a Fascinating Synergistic Ecology Effect
Hossam A. Nabwey, Maha A. Tony, Manasik M. Nour
February 10, 2024 (v1)
Subject: Environment
Keywords: acetylcellulose waste, Adsorption, isotherm models, levafix dye, wastewater treatment
Waste valorization is attracting not only the scientific world but also the world. Acetylcellulose wastes from cigarette filter residuals are signified as the largest global impact of solid waste. Acetylcellulose recycling for desired products is a promising way for environmental management. In this regard, the current investigation is dealing with the immersion of residual filters sequentially into aqueous solutions of alkali and ethanol before water washing, which converts them into a superhydrophobic acetylcellulose adsorbent material. The morphology and characteristics of the acetylcellulose fiber were characterized using a Scanning Electron Microscope (SEM) and Fourier-Transform infrared spectroscopy (FTIR). The adsorption tendency was checked for Levafix Blue dye compromised in an aqueous stream as a model textile polluted effluent. The experimental results exposed that the acetylcellulose fiber displayed a sensible textile dye elimination from the dying stream. Langmuir isotherm... [more]
A Review: Study on the Enhancement Mechanism of Heat and Moisture Transfer in Deformable Porous Media
Panpan Li, Cui Ma, Zhenqian Chen, Haoqi Wang, Yu Wang, Hao Bai
February 10, 2024 (v1)
Subject: Materials
Keywords: deformable porous media, heat and moisture transfer, irregular shrinkage deformation, microwave, ultrasound
The heat and moisture transfer process in deformable porous media commonly exists in material drying, solid waste treatment, bioengineering, and so on. The transfer process is accompanied by deformation of the solid skeleton and pore interface structure, which limits the transfer rate and affects quality. Microwave and ultrasound are the main representatives of reinforcement technology. However, as the moisture decreases, the energy utilization efficiency of microwaves decreases significantly. Based on the experimental and theoretical methods, the enhancement mechanism of ultrasound on the process is studied, which provides guidance for the wide application of ultrasonic enhancement. With the increase in ultrasound power, the pore area and the moisture effective diffusion coefficient gradually increase. A macroscope mathematical model for ultrasonic-coupled thermal-hydro-mechanical modeling is developed, and the results show that ultrasound increases the temperature gradient within mat... [more]
A Filtering-Based Stochastic Gradient Estimation Method for Multivariate Pseudo-Linear Systems Using the Partial Coupling Concept
Ping Ma, Yuan Liu, Yiyang Chen
February 10, 2024 (v1)
Keywords: data filtering, gradient search, multivariate system, parameter identification, partial coupling
Solutions for enhancing parameter identification effects for multivariate equation-error systems in random interference and parameter coupling conditions are considered in this paper. For the purpose of avoiding the impact of colored noises on parameter identification precision, an appropriate filter is utilized to process the autoregressive moving average noise. Then, the filtered system is transformed into a number of sub-identification models based on system output dimensions. Founded on negative gradient search, a new multivariate filtering algorithm employing a partial coupling approach is proposed, and a conventional gradient algorithm is derived for comparison. Parameter identification for multivariate equation-error systems has a high estimation accuracy and an efficient calculation speed with the application of the partial coupling approach and the data filtering method. Two simulations are performed to reveal the proposed method’s effectiveness.
Fruit Extract Mediated Green Synthesis of Silver and Copper Oxide Nanoparticles: Synthesis, Characterization, Antibacterial and Anticancer Activities
Sarika Dhir, Rohit Dutt, Rahul Pratap Singh, Mahima Chauhan, Tarun Virmani, Girish Kumar, Abdulsalam Alhalmi, Mohammed S. Aleissa, Hassan A. Rudayni, Mohammed Al-Zahrani
February 10, 2024 (v1)
Subject: Materials
Keywords: Amomum subulatum, antibacterial activity, anticancer activity, copper oxide NPs, silver NPs
This research presents a straightforward, effective, and eco-friendly method for the production of silver nanoparticles (AgNPs) and copper oxide nanoparticles (CuONPs) using the dried fruit of Amomum subulatum as a reducing, stabilizing, and capping agent. The formation of AgNPs and CuONPs is supported by the presence of a surface plasmon resonance band (SPR) at 440 nm for AgNPs and 245 nm for CuONPs. Additionally, the identification of specific biomolecules responsible for the synthesis of AgNPs and CuONPs was confirmed through FTIR spectra analysis. The Transmission electron microscope (TEM) images demonstrated that AgNPs and CuONPs had spherical shapes, with mean particle diameters of 20.6 nm and 24.7 nm, respectively. X-ray diffraction and selected area electron diffraction (SAED) analyses provided evidence of the crystalline nature of the synthesized AgNPs and CuONPs. Additionally, the presence of silver and copper elements was observed through energy-dispersive X-ray spectroscopy... [more]
Investigation of Natural Weak Interface Properties and Their Impact on Fracture Propagation in Shale Reservoirs
Qi Chen, Zhiqiang Huang, Xingjie Ling, Pengju Xu, Lanke Tu, Wenjing Liao, Jun Xie, Meng Wang, Yijing Chen, Lingli Li
February 10, 2024 (v1)
Keywords: 3D geological model, fracturing propagation path, multi cluster fracturing, natural fracture, shale reservoirs
Horizontal well multi-cluster fracturing technology is crucial for the economic development of fractured shale reservoirs. The abundance of natural fractures in shale reservoirs significantly influences the propagation path of hydraulic fractures and determines the formation of complex fracture networks. To investigate the impact of natural weak planes on the geometric parameters of fractures in shale reservoirs, we first conducted tests on the mechanical characteristics of core samples from outcropping shale in the Weiyuan area using the indoor three-point bending method and digital image correlation (DIC) technology, providing data validation for subsequent numerical models. Secondly, considering the interaction between hydraulic and natural weak planes in three-dimensional space, we established a three-dimensional numerical model for horizontal well fracturing to simulate the synchronous competition and expansion of fractures in multi-cluster fracturing. Based on this foundation, we... [more]
Advanced Biomedical Applications of Multifunctional Natural and Synthetic Biomaterials
Mariana Chelu, Adina Magdalena Musuc
February 10, 2024 (v1)
Subject: Materials
Keywords: bioceramics, biocompatibility, biodegradability, biomaterials, biomedical, biopolymers, tissue engineering
Biomaterials are mostly any natural and synthetic materials which are compatible from a biological point of view with the human body. Biomaterials are widely used to sustain, increase, reestablish or substitute the biological function of any injured tissue and organ from the human body. Additionally, biomaterials are uninterruptedly in contact with the human body, i.e., tissue, blood and biological fluids. For this reason, an essential feature of biomaterials is their biocompatibility. Consequently, this review summarizes the classification of different types of biomaterials based on their origin, as natural and synthetic ones. Moreover, the advanced applications in pharmaceutical and medical domains are highlighted based on the specific mechanical and physical properties of biomaterials, concerning their use. The high-priority challenges in the field of biomaterials are also discussed, especially those regarding the transfer and implementation of valuable scientific results in medical... [more]
Study and Characterization of H3PO4 Activated Carbons Prepared from Jujube Stones for the Treatment of Industrial Textile Effluents
Nasma Bouchelkia, Kheira Benazouz, Amal Mameri, Lazhar Belkhiri, Nadia Hamri, Hayet Belkacemi, Abdelhalim Zoukel, Abdeltif Amrane, Fodil Aoulmi, Lotfi Mouni
February 10, 2024 (v1)
Subject: Materials
Keywords: activated carbon, Adsorption, chemical activation, textile effluent, wastewater treatment
Dyes are responsible for major environmental issues globally due to their toxicity, large-scale production, and extensive use in various industrial sectors. Pollution caused by hazardous dyes is mainly due to textile waste, which is constantly discharged into the aquatic system, often causing harm to humans and affecting water quality. In recent years, the removal of dyes from industrial textile wastewater has been a major challenge. Numerous technologies and methods have been developed to remove dyes from wastewater and meet clean water requirements. In this study, the effectiveness of activated carbon prepared by chemical activation of jujube stones for textile wastewater treatment was investigated. The effects of the concentration of H3PO4 and the carbonization temperature on the activated carbon’s properties were studied. Several physicochemical methods, including Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction, methylene blue i... [more]
Study on Flow Characteristics of a Single Blade Breakage Fault in a Centrifugal Pump
Huairui Li, Qian Huang, Sihan Li, Yunpeng Li, Qiang Fu, Rongsheng Zhu
February 10, 2024 (v1)
Keywords: blade breakage, centrifugal pump, fault diagnosis, flow characteristics, pressure pulsation
The precise identification of faults in centrifugal pumps is crucial for ensuring their safe and stable operation, given their significance as vital industrial equipment. This article aims to rigorously examine and analyze the flow characteristics of centrifugal pumps under two specific conditions: normal blade operation and a single blade breakage fault. Through systematic comparison and in-depth study, this article sheds light on distinguishing flow patterns exhibited by these pumps under both normal and fault scenarios. Utilizing validated numerical simulation methods, a thorough analysis is conducted to explore the flow condition and energy characteristics of the impeller channel following the breakage of a single blade. Additionally, the article investigates changes in the pressure pulsation characteristics of the pump volute as a result. The numerical simulation results reveal that the head of the centrifugal pump decreases at all flow points when a single blade breaks. However,... [more]
The Influence of Oxidizing and Non-Oxidizing Biocides on Enzymatic and Microbial Activity in Sugarcane Processing
Evan Terrell, Yunci Qi, Gillian O. Bruni, Emily Heck
February 10, 2024 (v1)
Subject: Biosystems
Keywords: amylase, biocides, dextran, dextranase, raw sugar, starch, sugarcane
Processing aids are utilized during raw sugar manufacturing at sugarcane processing facilities to mitigate unwanted contamination from microorganisms and their associated exopolysaccharides (EPS). Microorganisms in processing facilities contribute to sugar losses through sucrose inversion and consumption, with many bacteria strains subsequently producing dextran and fructan EPS that can cause downstream issues related to viscosity and crystallization. Similar issues also result from the presence of unwanted starches from plant material in cane juices. Processing aids include biocides for bacterial inhibition, and enzymes (e.g., dextranase, amylase) to break down polysaccharides in juices. However, oxidizing biocide processing aids (e.g., sodium hypochlorite) may inhibit enzymatic processing aid activity. In this study, biocides (sodium hypochlorite, carbamate, and hop extract) and enzymes (dextranase and amylase) were simultaneously added to sugarcane juice to measure residual enzymati... [more]
Catalytic Hydrogenation of Nitrate over Immobilized Nanocatalysts in a Multi-Phase Continuous Reaction System: System Performance, Characterization and Optimization
Ana Sofia G. G. Santos, João Restivo, Carla Alexandra Orge, Manuel Fernando R. Pereira, Olívia Salomé G. P. Soares
February 10, 2024 (v1)
Subject: Materials
Keywords: continuous reactor, denitrification, macrostructured catalysts, multi-phase reaction
Nitrate catalytic reduction in a continuous system was studied in the presence of Pd-Cu macrostructured catalysts synthesized through a novel washcoating methodology of the pre-formed bimetallic powder catalyst. The present work aims to understand the behavior of the macrostructured bimetallic catalyst in the presence of different reaction conditions in order to achieve the design of an optimized facility that can produce the best catalytic results: maximum NO3− conversion with enhanced N2 selectivity. The residence time of the inlet solution and the catalyst concentration in the reactor proved to be the parameters that most influenced the conversion and selectivity due to the important role that these parameters play in the hydrodynamic conditions of the reactor. A higher loading of catalyst and lower inlet flow rates allow promoting a higher contact time between the three phases that participate in the reaction (G-L-S). The most efficient reaction conditions (three pieces of the macr... [more]
Synergies between Lean and Industry 4.0 for Enhanced Maintenance Management in Sustainable Operations: A Model Proposal
David Mendes, Pedro D. Gaspar, Fernando Charrua-Santos, Helena Navas
February 10, 2024 (v1)
Subject: Energy Policy
Keywords: energy transition, Industry 4.0, Lean Philosophy, maintenance, maintenance management, model, Renewable and Sustainable Energy, sensors, TPM
Companies actively seek innovative tools and methodologies to enhance operations and meet customer demands. Maintenance plays a crucial role in achieving such objectives. This study identifies existing models that combine Lean Philosophy and Industry 4.0 principles to enhance decision-making and activities related to maintenance management. A comprehensive literature review on key concepts of Lean Philosophy and Industry 4.0, as well as an in-depth analysis of existing models that integrate these principles, is performed. An innovative model based on the synergies between Lean Philosophy and Industry 4.0, named the Maintenance Management in Sustainable Operations (MMSO) model, is proposed. A pilot test of the application of the MMSO model on a conveyor belt led to an operational time increase from 82.3% to 87.7%, indicating a notable 6.6% improvement. The MMSO model significantly enhanced maintenance management, facilitating the collection, processing, and visualization of data via int... [more]
Flow Visualisation and Evaluation Studies on Metalworking Fluid Applications in Manufacturing Processes—Methods and Results
Udo Fritsching, Lizoel Buss, Teresa Tonn, Lukas Schumski, Jurgen Gakovi, Johnson David Hatscher, Jens Sölter, Kerstin Avila, Bernhard Karpuschewski, Julian Frederic Gerken, Tobias Wolf, Dirk Biermann, Christian Menze, Hans-Christian Möhring, Elio Tchoupe, Lukas Heidemanns, Tim Herrig, Andreas Klink, Kaissar Nabbout, Martin Sommerfeld, Fabian Luther, Ingo Schaarschmidt, Andreas Schubert, Markus Richter
February 10, 2024 (v1)
Subject: Other
Keywords: flow visualisation, high-speed imaging, manufacturing process, metalworking fluid, particle image velocimetry, shadowgraphy
Metalworking operations rely on the successful application of metalworking fluids (MWFs) for effective and efficient operation. Processes such as grinding or drilling often require the use of MWFs for cooling, lubrication, and chip removal. Electrochemical machining processes require electrolyte flow to operate. However, in those machining operations, a fundamental understanding of the mode of action of MWF is lacking due to the unknown flow dynamics and its interaction with the material removal during the process. Important information on the behaviour of MWFs during machining can be obtained from specific experimental flow visualisation studies. In this paper, promising flow visualisation analysis techniques applied to exemplary machining processes (grinding, sawing, drilling, and electrochemical machining) are presented and discussed. Shadowgraph imaging and flow measurements, e.g., particle image velocimetry, allow the identification of typical flow and MWF operating regimes in the... [more]
Hierarchical Optimization Based on Deep Reinforcement Learning for Connected Fuel Cell Hybrid Vehicles through Signalized Intersections
Hongquan Dong, Lingying Zhao, Hao Zhou, Haolin Li
January 12, 2024 (v1)
Subject: Other
Keywords: fuel economy, hierarchical joint optimization, hydrogen fuel cell hybrid vehicle, traveling efficiency, urban roads driving scenario
With the advantages of non-pollution and energy-saving, hydrogen fuel cell hybrid vehicles (HFCHVs) are regarded as one of the potential traveling ways in the future. The energy management of FCHVs has a huge energy-efficient potential which is combined with the Internet of Things (IOT) and auto-driving technologies. In this paper, a hierarchical joint optimization method that combines deep deterministic policy gradient and dynamic planning (DDPG-DP) for speed planning and energy management of the HFCHV is proposed for urban road driving scenarios. The results demonstrate that when the HFCHV is operating in driving scenario 1, the traveling efficiency of the DDPG-DP algorithm is 17.8% higher than that of the IDM-DP algorithm, and the hydrogen fuel consumption is reduced by 2.7%. In contrast, the difference in the traveling efficiency and fuel economy is small among the three algorithms in driving scenario 2, the number of idling/stop situations of the DDPG-DP algorithm is reduced compa... [more]
Response Surface Methodology (RSM) Optimization of Pulsed Electric Field (PEF) Pasteurization Process of Milk-Date Beverage
Mahmoud Younis, Khaled A. Ahmed, Isam A. Mohamed Ahmed, Hany M. Yehia, Diaeldin O. Abdelkarim, Abdulla Alhamdan, Ahmed Elfeky, Mansour N. Ibrahim
January 12, 2024 (v1)
Keywords: date powder, pulsed electric field, response surface methodology, total viable count
Milk beverage with added natural sweetener is well appreciated by consumers as a nutritious and healthy product with unique sensorial quality attributes. However, this product requires a suitable pasteurization method without significant impact on the sensorial and physicochemical quality characteristics of the product. This study optimizes the pulsed electric filed (PEF) conditions for the pasteurization of a milk-date beverage with conserved physicochemical quality properties. The effect of process variables, such as pulse off time (20, 30, and 40 μs), number of pulses (20, 50, and 80), powder ratio (10, 15, 20, and 25% w/w), storage time (2, 4, and 6 days), and storage temperature (5, 15, and 25 °C) on the responses of total viable count (TVC), color difference (∆E), pH, and total soluble solids (TSS) was evaluated using the RSM central composite design (CCD). Pulse off time, number of pulses, date powder/milk ratio (w/w), storage time, and storage temperature greatly impacted the m... [more]
Structural Optimization of Annular Thermoelectric Module Applied to Liquefied Natural Gas Cold Energy Recovery
Yulong Zhao, Hongmei Diao, Wenjie Li, Zhiwei Xuan, Qi Zhang, Yulin Wang, Minghui Ge
January 12, 2024 (v1)
Keywords: annular, cold energy, liquefied natural gas, structural optimization, thermoelectric
The gasification of liquefied natural gas (LNG) is characterized by a substantial release of cold energy, which can be utilized for power generation via thermoelectric generator (TEG). Employing a gasifier integrated with a thermoelectric generator for LNG gasification allows for the recovery of cold energy and its conversion to useful power, a process that holds significant potential for widespread application. In the study, a thermoelectric model has been developed for an annular thermoelectric module, which formed a new category of gasifier tube. The influence of the module’s structure as well as the heat transfer parameters on the thermoelectric performance was examined. The results revealed that an optimum height of the thermoelectric leg, specifically 2 mm, maximized the output power while allowing the thermoelectric conversion efficiency to reach a peak of 3.25%. Another noteworthy finding is that an increase in the central angle of the thermoelectric leg leads to a concomitant... [more]
Using Adsorption Energy Distribution for Parameter Estimation of Competitive Cofactor Coupled Enzyme Reaction
Thomas Waluga, Mirko Skiborowski
January 12, 2024 (v1)
Keywords: adsorption energy distribution, alcohol dehydrogenase, kinetic modeling
The chemical and biotechnology industries are facing new challenges in the use of renewable resources. The complex nature of these materials requires the use of advanced techniques to understand the kinetics of reactions in this context. This study presents an interdisciplinary approach to analyze cofactor coupled enzymatic two-substrate kinetics and competitive two-substrate kinetics in a fast and efficient manner. By studying the adsorption energy distribution (AED), it is possible to determine the individual parameters of the reaction kinetics. In the case of a single alcohol reaction, the AED is able to identify parameters in agreement with the literature with few experimental data points compared to classical methods. In the case of a competitive reaction, AED analysis can automatically determine the number of competing substrates, whereas traditional nonlinear regression requires prior knowledge of this information for parameter identification.
Integration of Renewable-Energy-Based Green Hydrogen into the Energy Future
Ismail Marouani, Tawfik Guesmi, Badr M. Alshammari, Khalid Alqunun, Ahmed Alzamil, Mansoor Alturki, Hsan Hadj Abdallah
January 12, 2024 (v1)
Keywords: efficiency improvement, electrolysis, green hydrogen production, leading countries in this field, net-zero gas emissions, optimization techniques, Renewable and Sustainable Energy, Renewable and Sustainable Energy, technologies used
There is a growing interest in green hydrogen, with researchers, institutions, and countries focusing on its development, efficiency improvement, and cost reduction. This paper explores the concept of green hydrogen and its production process using renewable energy sources in several leading countries, including Australia, the European Union, India, Canada, China, Russia, the United States, South Korea, South Africa, Japan, and other nations in North Africa. These regions possess significant potential for “green” hydrogen production, supporting the transition from fossil fuels to clean energy and promoting environmental sustainability through the electrolysis process, a common method of production. The paper also examines the benefits of green hydrogen as a future alternative to fossil fuels, highlighting its superior environmental properties with zero net greenhouse gas emissions. Moreover, it explores the potential advantages of green hydrogen utilization across various industrial, c... [more]
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