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Records with Keyword: Optimization
Showing records 151 to 175 of 966. [First] Page: 3 4 5 6 7 8 9 10 11 Last
Oil Production Optimization Using Q-Learning Approach
Mazyar Zahedi-Seresht, Bahram Sadeghi Bigham, Shahrzad Khosravi, Hoda Nikpour
June 21, 2024 (v1)
Subject: Optimization
Keywords: data science, Machine Learning, oil production, oil recovery factor, Optimization, Q-learning
This paper presents an approach for optimizing the oil recovery factor by determining initial oil production rates. The proposed method utilizes the Q-learning method and the reservoir simulator (Eclipse 100) to achieve the desired objective. The system identifies the most efficient initial oil production rates by conducting a sufficient number of iterations for various initial oil production rates. To validate the effectiveness of the proposed approach, a case study is conducted using a numerical reservoir model (SPE9) with simplified configurations of two producer wells and one injection well. The simulation results highlight the capabilities of the Q-learning method in assisting reservoir engineers by enhancing the recommended initial rates.
Optimizing the Thickness of Multilayer Thermal Insulation on Different Pipelines for Minimizing Overall Cost-Associated Heat Loss
Mohammed R. A. Alrasheed
June 7, 2024 (v1)
Subject: Environment
Keywords: energy savings, life cycle cost analysis, multi-objective genetic algorithm, multilayer insulation, Optimization, thermal insulation
Optimizing the multilayer thermal insulation of pipelines transporting liquids and gases at higher than ambient temperatures is crucial for heat energy conservation and cost optimization. This study utilizes a multi-objective genetic algorithm to optimize the multilayer thermal insulation thickness around a pipe carrying fluid to minimize heat loss and associated costs. The model adopted mathematical associations between design variables and the overall installation cost of layers over a pipe from the available literature. The proposed model considered one or more insulation layers of rock wool and calcium silicate to oil pipelines containing steam, furfural, reduced crude or 300-distillate oil. All calculations considered fixed-charge rates as a fraction of 1 or 0.15. The results were compared with standard values and those predicted by other researchers in the literature. For the steam line, the standard insulation thickness was 50 mm, jumping to 327 mm for rock wool and 232 mm for c... [more]
Exergy and Environmental Analysis for Optimal Condition Finding of a New Combined Cycle
Ibrahim B. Mansir
June 7, 2024 (v1)
Subject: Environment
Keywords: energy recovery, exergo-economic, intercooled gas turbine, Kalina cycle, Optimization
In this paper, various thermal energy systems are studied to recover waste heat from gas turbines with different configurations. The exergy analysis and environmental examination are applied to achieve better insight into the suggested systems. Also, multi-objective optimization is employed to find the optimal condition of the introduced plants. In this work, various systems such as gas turbine (GT), organic Rankine cycle (ORC), and Kalina cycle (KC) with Proton Exchange Membrane (PEM) electrolyzer are combined to achieve a new system design. In this study, Engineering Equation Solver (V11.755) and Matlab (R2023a) software are used to simulate and optimize the proposed system. The comparison of systems shows that the combustion chamber with 3622 kW has the most considerable exergy destruction in the IGT/ORC-KC plant. The comparative investigation shows that IGT/ORC-KC has the highest output at 5659 kW, while the smallest exergy destruction is associated with the IGT system with 1779 kW... [more]
Metaheuristic Optimization Algorithm Based Cascaded Control Schemes for Nonlinear Ball and Balancer System
Farhan Zafar, Suheel Abdullah Malik, Tayyab Ali, Amil Daraz, Atif M. Alamri, Salman A. AlQahtani, Farkhunda Bhatti
June 7, 2024 (v1)
Keywords: ball and balancer, cuckoo search algorithm, gradient based optimization and whale optimization, grey wolf optimization algorithm, Optimization, PIDD2-PI, TID-F, underactuated system
The ball and balancer system is a popular research platform for studying underactuated mechanical systems and developing control algorithms. It is a well-known two-dimensional balancing problem that has been addressed by a variety of controllers. This research work proposes two controllers that are proportional integral derivative-second derivative-proportional integrator (PIDD2-PI) controller and tilt integral derivative with filter (TID-F) controller in a multivariate, electromechanical, and nonlinear under-actuated ball and balancer system. Integral Time Absolute Error (ITAE) is an objective function used for designing controllers because of its ability to be more sensitive to overshooting as well as reduced settling time and steady-state error. As part of the analysis, four metaheuristic optimization algorithms are compared in the optimization of proposed control strategies for cascaded control of the ball and balancer system. The algorithms are the Grey Wolf optimization algorithm... [more]
Multi-Criteria Optimization Conditions for the Recovery of Bioactive Compounds from Levisticum officinale WDJ Koch Roots Using Green and Sustainable Ultrasound-Assisted Extraction
Michał Plawgo, Sławomir Kocira, Andrea Bohata
June 7, 2024 (v1)
Keywords: antioxidant, Extraction, flavonoids, lovage, multi-criteria design, Optimization, Pareto, polyphenols
Given that ultrasound-assisted aqueous extraction is gaining importance within “green technology” and to increase the efficiency of extracting bioactive compounds from Levisticum officinale root waste, optimization of its parameters was undertaken. Multi-objective (multi-criteria) optimization can be an extremely promising tool not only for designing and analyzing the extraction process, but also for making process-control decisions. Therefore, the main objective of this study was to develop and optimize an environmentally friendly ultrasound-assisted extraction methodology for the aqueous extraction of bioactive compounds from the roots of Levisticum officinale, which are considered a by-product. The focus was on determining the optimal extraction conditions of the independent variables, such as solid−liquid ratio, extraction time and ultrasound power, so that the optimized extracts present the highest bioactive potential expressed in terms of levels of phenolic compounds, flavonoids,... [more]
Response Surface Methodology—Central Composite Design Optimization Sugarcane Bagasse Activated Carbon under Varying Microwave-Assisted Pyrolysis Conditions
Xuexue Chen, Yunji Pei, Xinran Wang, Wenlin Zhou, Li Jiang
June 6, 2024 (v1)
Keywords: activated carbon, microwave pyrolysis, Optimization, response surface methodology, sugarcane bagasse
Sugarcane bagasse (SB) is a widely available agro-industrial waste residue in China that has the potential to be converted into a cost-effective and renewable adsorbent. In this study, activated carbon (AC) was prepared from SB by microwave vacuum pyrolysis using H3PO4 as the activator. To enhance the sorption selectivity and yield, the pyrolysis process of SB-activated carbon (SBAC) should be well-designed. Central composite design was employed as an optimized experiment design, and response surface methodology was used to optimize the process parameters for maximized SBAC yield and its iodine number. The results showed that the optimized parameters obtained for the SBAC are 2.47 for the impregnation ratio (IR), 479.07 W for microwave power (MP), 23.86 mm for biomass bed depth, and 12.96 min for irradiation time, with responses of 868.7 mg/g iodine number and 43.88% yield. The anticipated outcomes were substantiated, revealing a marginal 5.4% variance in yield and a mere 1.9% discrepa... [more]
A Novel Approach to Optimizing Grinding Parameters in the Parallel Grinding Process
Tengfei Yin, Hanqian Zhang, Wei Hang, Suet To
June 6, 2024 (v1)
Subject: Materials
Keywords: Optimization, parallel grinding, speed ratio, surface generation, surface roughness
Hard materials have found extensive applications in the fields of electronics, optics, and semiconductors. Parallel grinding is a common method for fabricating high-quality surfaces on hard materials with high efficiency. However, the surface generation mechanism has not been fully understood, resulting in a lack of an optimization approach for parallel grinding. In this study, the surface profile formation processes were analyzed under different grinding conditions. Then, a novel method was proposed to improve surface finish in parallel grinding, and grinding experiments were carried out to validate the proposed approach. It was found that the denominator (b) of the simplest form of the rotational speed ratio of the grinding wheel to the workpiece has a great influence on surface generation. The surface finish can be optimized without sacrificing the machining efficiency by slightly adjusting the rotational speeds of the wheel or the workpiece to make the value of b close to the ratio... [more]
A Study of the Top-Coal-Drawing Law of Steeply Inclined and Extremely Thick Coal Seams in the Wudong Coal Mine
Jiantao Cao, Longquan Wu, Xingping Lai, Baoxu Yan, Haoyu Zhu, Hao Qiao
June 6, 2024 (v1)
Subject: Materials
Keywords: coal-drawing control, coal-drawing technology, extremely thick coal seams, Optimization, steep incline, top-coal-drawing rate
In addressing the issue of a low drawing rate in a steeply inclined and extremely thick coal seam, this study focused on the engineering background of the +575 horizontal working faces in the Wudong Coal Mine. By utilizing physical similarity simulation experiments, research was carried out on the top-coal-drawing rate and the gangue ratio at different coal-drawing intervals in horizontal segment mining for steeply inclined and thick coal seams, in which the relationships between the top-coal-drawing law and the drawing interval and technologies were revealed. The discrete element method was used to establish a numerical simulation model for the horizontal segment mining of steeply inclined and thick coal seams, and the roof-drawing law in the cases of the three-interval-group-of-support and drawing-once-every-two-support methods were analyzed before finally obtaining the optimal drawing technology. Through field practice, the coal-drawing effect of the technology was verified. The res... [more]
Performance and Formula Optimization of Graphene-Modified Tungsten Carbide Coating to Improve Adaptability to High-Speed Fluid Flow in Wellbore
Minsheng Wang, Lingchao Xuan, Lei Wang, Jiangshuai Wang
June 5, 2024 (v1)
Subject: Optimization
Keywords: coating, graphene, Optimization, PDC drill bit, tungsten carbide
In order to improve the erosion resistance of steel PDC (Polycrystalline Diamond Compact) bit under high-speed fluid flow conditions underground, it is necessary to develop a high-performance erosion-resistant coating. In this paper, laser cladding was used to prepare the new coating by modifying tungsten carbide with graphene. And the effects of tungsten carbide content and graphene content on the coating performance have been thoroughly studied and analyzed to obtain the optimal covering layer. The research results indicate that, for new coatings, 60% tungsten carbide and 0.3% graphene are the optimal ratios. After adding tungsten carbide, the hardness has significantly improved. However, when the tungsten carbide content further increases more than 30%, the increase in hardness is limited. In addition, when the content of graphene is more than 0.3%, the branched structure becomes thicker. In detail, this is a phenomenon where the segregation of Cr, Si, and W becomes very obvious aga... [more]
Growth Substrate Geometry Optimization for the Productive Mechanical Dry Transfer of Carbon Nanotubes
Andre Butzerin, Sascha Weikert, Konrad Wegener
June 5, 2024 (v1)
Subject: Optimization
Keywords: mechanical dry transfer, Optimization, productivity, substrate geometry, suspended carbon nanotube
The selection of growth substrate geometries for the mechanical dry transfer of carbon nanotubes to device substrates depends on the precision of the assembly equipment. Since these geometries play a decisive role in the overall efficiency of the process, an investigation of the most important geometry parameters is carried out. The substrate geometry affects the number of carbon nanotubes suspended during the growth process and the speed of mechanical assembly at the same time. Since those two criteria are interlinked and affect productivity, a meta-model for the growth and selection of the nanotubes is simulated and a time study of the resulting assembly motions is subsequently performed. The geometry parameters are then evaluated based on the total number of suspended carbon nanotubes and the throughput rate, measured in transfers per hour. The accuracy specifications are then taken into account. Depending on the overall accuracy that can be achieved, different offset angles and ove... [more]
Simultaneous Integration of the Methanol-to-Olefin Separation Process and Heat Exchanger Network Based on Bi-Level Optimization
Xiaohong Han, Ning Li, Yibo She, Jianli Feng, Heng Liu, Guilian Liu, Zaoxiao Zhang
June 5, 2024 (v1)
Keywords: distillation system, Heat Exchanger Network, MTO, Optimization, PSO
The separation section of the methanol-to-olefin (MTO) process is energy-intensive, and the optimization and heat integration can enhance energy efficiency and reduce costs. A bi-level optimization model framework is proposed to optimize the separation process and simultaneously integrate the heat exchanger network (HEN). The upper level employs a data-driven BP neural network proxy model instead of the mechanism model for the separation process, while the lower level adopts a stage-wise superstructure for the HEN without stream splits. The interaction between the two systems is realized effectively through information exchange. A bi-level particle swarm algorithm is employed to optimize complex problems and determine the optimal operational parameters for the distillation system and HEN. Compared with the typical sequential synthesis method, the optimization by the proposed approach reduces the total annual cost by 1.4293×106 USD/y, accounting for 4.76%.
Experimental Research of Ultrasonic Cavitation Evolution Mechanism and Model Optimization of RUREMM on Cylindrical Surface
Wenjun Tong, Lin Li
June 5, 2024 (v1)
Subject: Optimization
Keywords: cavitation bubble, micro-pits, Optimization, surface quality, ultrasonic field
Micro-pits are widely used in the aerospace and tribology sectors on cylindrical surfaces and electrochemical micromachining which are of great significance for the high material removal rate, absence of tool wear, and mechanical stress, while facing significant challenges such as stray corrosion and low machining efficiency. Aiming at the above problems, this paper proposes a comprehensive method called radial ultrasonic rolling electrochemical micromachining (RUREMM) in which an ultrasonic field has been added onto the cylindrical surface. First, a theoretical model was created to gain the rules of the formation and collapse of bubbles in the liquid medium. Second, to analyze the optimal size of the cathode electrode, the COMSOL5.2 simulation software was proposed to research the influence of the electric field on the different dimensions, and the influences of different parameters in RUREMM on material depth/diameter ratio and roughness are explored through processing experiments. R... [more]
Stick−Slip Characteristics of Drill Strings and the Related Drilling Parameters Optimization
Chao Wang, Wenbo Chen, Zhe Wu, Jun Li, Gonghui Liu
February 10, 2024 (v1)
Subject: Optimization
Keywords: drill string, drilling parameter, Optimization, stick–slip vibration
To eliminate or reduce stick−slip vibration in torsional vibration of the drilling string and improve the rate of penetration (ROP), a stick−slip vibration model of the drilling string considering the ROP was established based on the multidimensional torsional vibration model of the drilling string. The model was verified by simulation analysis. The characteristics of the drilling string stick−slip vibration in the three stages of stationary, slip, and stick were analyzed. This paper investigated the influence of rotary torque, rotary speed, and weight on bit (WOB) on stick−slip vibrations in the drill string. Based on this, the relationship between the drilling parameters and ROP was established. Drilling parameter optimization was completed for soft, medium-hard, and hard formations. Results showed that appropriately increasing torque and decreasing WOB can reduce or even eliminate stick−slip vibrations in the drill string and increase the ROP. The parameter optimization increased th... [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]
Process Simulation and Integration of Natural Gas Condensate Recovery Using Ethane−Propane Refrigerant Mixture
Jin Sun, Rujin Zhou, Li Wang, Xinye Zeng, Shaolin Hu, Haoshui Yu, Liangliang Jiang
January 5, 2024 (v1)
Keywords: Aspen HYSYS, combined refrigeration, Optimization, process simulation
Separating heavy components from natural gas not only enhances safety, improves pipeline transportation, ensures product quality, and addresses environmental considerations, but it also exerts an influence on global energy trends. Therefore, separating heavy components is necessary and can result in beneficial goods. This article presents a comprehensive study on the process simulation and optimization of the recovery of natural gas condensate via the combined refrigeration of a mixture of ethane and propane as a refrigerant. The optimization objectives include maximizing the recovery of ethane and propane, minimizing energy consumption, and achieving desired product quality targets. A sensitivity analysis was performed to assess the impact of key parameters on process performance. Using Aspen HYSYS software, the influence of the cooler outlet stream temperature and expander outlet stream pressure on the shaft power and profit of a dry gas compressor was analyzed based on the operating... [more]
Multi-Objective Optimization of Drilling GFRP Composites Using ANN Enhanced by Particle Swarm Algorithm
Mohamed S. Abd-Elwahed
September 21, 2023 (v1)
Keywords: artificial neural network, drilling process, glass fiber reinforced polymer, Optimization, Particle Swarm Optimization, response surface analysis, sustainable machining
This paper aims to optimize the quality characteristics of the drilling process in glass fiber-reinforced polymer (GFRP) composites. It focuses on optimizing the drilling parameters with drill point angles concerning delamination damage and energy consumption, simultaneously. The effects of drilling process parameters on machinability were analyzed by evaluating the machinability characteristics. The cutting power was modeled through drilling parameters (speed and feed), drill point angle, and laminate thickness. The response surface analysis and artificial neural networks enhanced by the particle swarm optimization algorithm were applied for modeling and evaluating the effect of process parameters on the machinability of the drilling process. The most influential parameters on machinability properties and delamination were determined by analysis of variance (ANOVA). A multi-response optimization was performed to optimize drilling process parameters for sustainable drilling quality cha... [more]
Multi-Response Optimization Analysis of the Milling Process of Asphalt Layer Based on the Numerical Evaluation of Cutting Regime Parameters
Teodor Dumitru, Marius Gabriel Petrescu, Maria Tănase, Costin Nicolae Ilincă
September 21, 2023 (v1)
Subject: Optimization
Keywords: ANOVA, asphalt concrete, chip section area, cutting forces, DEM, DOE, GRA, milling teeth, Optimization
The present study aimed to optimize the process parameters (milling depth and advanced speed) for an asphalt milling operation using a multi-response approach based on Taguchi design of experiments (DOE) and Grey Relational Analysis (GRA). Nine simulations tests were conducted using Discrete Element Method (DEM) in order to determine the forces acting on the cutting tooth support and tip. The considered performance characteristics were cutting forces (smaller is better category) and chip section area (larger is better category). A Grey Relational Grade (GRG) was determined from GRA, allowing to identify the optimal parameter levels for the asphalt milling process with multiple performance characteristics. It was found that that the optimal milling parameters for multi-response analysis are a milling depth of 200 mm and an advanced speed of 30 mm/min. Furthermore, analysis of variance (ANOVA) was used to determine the most significant factor influencing the performance characteristics.... [more]
Efficient Biosynthesis of Phosphatidylserine in a Biphasic System through Parameter Optimization
Bishan Guo, Juntan Wang, Mengxue Zhang, Huiyi Shang, Rui Du, Fayun Wang, Hui Wang, Jun Xu, Haihua Zhu
September 21, 2023 (v1)
Subject: Biosystems
Keywords: Optimization, phosphatidylcholine, phosphatidylserine, phospholipase D, transphosphatidylation
Phosphatidylserine (PS) has significant biological and nutritional effects and finds wide applications in the food, pharmaceutical, and chemical industries. To produce high-value PS efficiently, phospholipase D (PLD)-induced transphosphatidylation of low-value phosphatidylcholine (PC) with L-serine has been explored. In this research, we purified recombinant PLD from Streptomyces antibioticus SK-3 using ion exchange chromatography and gel filtration chromatography. Subsequently, we thoroughly characterized the purified enzyme and optimized the transphosphatidylation conditions to identify the most favorable settings for synthesizing PS in a biphasic system. The purified recombinant PLD displayed a robust transphosphatidylation function, facilitating efficient catalysis in the synthesis of PS. Under the optimal conditions (butyl acetate/enzyme solution 1:1, L-serine 160 mg/mL, soybean lecithin 2 mg/mL, and MgCl2 15 mM, at 50 °C for 2.5 h with shaking), we achieved a conversion rate of 9... [more]
Model-Based Optimization of Multi-Stage Nanofiltration Using the Solution-Diffusion−Electromigration Model
Tobias Hubach, Stefan Schlüter, Christoph Held
September 21, 2023 (v1)
Keywords: ion permeances, lithium, magnesium, membrane separation, Modelling, Optimization, process design, solution-diffusion–electromigration
Nanofiltration is well suited to separate monovalent ions from multivalent ions, such as the separation of Li+ and Mg2+ from seawater, a potential lithium source for the production of lithium-ion batteries. To the best of our knowledge, there is no existing work on the optimization of a multi-stage membrane plant that differentiates between different ions and that is based on a validated transport model. This study presents a method for modeling predefined membrane interconnections using discretization along the membrane length and across the membrane thickness. The solution-diffusion−electromigration model was used as the transport model in a fundamental membrane flowsheet, and the model was employed to optimize a given flowsheet with a flexible objective function. The methodology was evaluated for three distinct separation tasks, and optimized operating points were found. These show that permeances and feed concentrations might cause negative rejections and positive rejections (espec... [more]
First Law Optimization and Review of Double and Triple-Effect Parallel Flow Vapor Absorption Refrigeration Systems
Md. Azhar
September 20, 2023 (v1)
Subject: Optimization
Keywords: Optimization, parallel flow, thermodynamic analysis, triple effect, vapor absorption refrigeration system
Parallel flow double and triple-effect vapor absorption cooling systems (VACS) are trying to meet the challenges of vapor compression cooling systems due to their better performance. Therefore, the present study deals with the review, thermodynamic analysis, and optimization of operating parameters for both double and triple-effect VACS. Lithium bromide water was selected as the working fluid, while liquified petroleum gas (LPG) and compressed natural gas (CNG) were taken as the source of energy to drive both the VACS. Detailed First Law analysis, i.e., coefficient of performance (COP), was examined along with the optimization of operating parameters (such as salt concentration and operating generators temperature at different pressure levels) and the volume flow rate of the gases. Optimization was carried out for maximum COP of the VACS using an iterative technique. Our results show that the COP of the triple-effect system was approximately 32% higher than the double effect, while 15−... [more]
Plasma-Arc-Flow Technology for Sustainable Treatment of High-Impact Fluid Waste: A Graphene-Based Material for Industrial-Wastewater Purification
Carmine Mongiello, Mohammad Ghoreishi, Vinod Kumar Sharma, Liberato Verdoliva, Sabato Aprea, Paolo Venturini, Gianluca Pesce
September 20, 2023 (v1)
Subject: Materials
Keywords: Energy Efficiency, graphene, Optimization, plasma arc flow, wastewater treatment
The research presented aimed to address the treatment of fluid waste with significant environmental impact by utilizing plasma technology, specifically plasma arc flow (PAF). The goal was to develop a novel purification material based on graphene for industrial applications and to optimize the treatment process. Analysis and monitoring of a submerged arc plasma reactor were the main goals of this research. This entailed a careful examination of the incoming wastewater that needed to be treated with the goal of identifying its precise composition characteristics with the relative tolerances needed for the reactions that were to follow in the reactor. The focus of the analysis was on input-parameter optimization, production of characteristic curves, and analysis of the factors affecting hydrogen evolution in syngas. Additionally, the study investigated how to determine the best viscosity for a particular input matrix by carrying out an evaluation study. The effects of this parameter were... [more]
Optimization of Supercritical Carbon Dioxide Fluid Extraction of Medicinal Cannabis from Quebec
Hinane Boumghar, Mathieu Sarrazin, Xavier Banquy, Daria C. Boffito, Gregory S. Patience, Yacine Boumghar
August 3, 2023 (v1)
Subject: Optimization
Keywords: Box–Behnken, cannabinoids, Optimization, supercritical carbon dioxide
Research on cannabis oil has evolved to encompass the pharmaceutical industry for the therapeutic potential of the active compounds for pathologies such as Alzheimer, auto-immune disorders, and cancer. These debilitating diseases are best treated with cannabinoids such as tetrahydrocannabinol (∆9-THC), cannabigerol (CBG), and cannabinol (CBN), which relieve neuropathic pain and stimulate the immune system. We extracted cannabinoids from plants with supercritical CO2 and produced an extract with a total yield close to 26%. The three-level Box−Behnken experimental design considered four factors: Temperature, pressure, CO2 flow rate, and processing time, with predetermined parameters at low, medium, and high levels. The mathematical model was evaluated by regression analysis. The yield of ∆9-THC and CBG reached a maximum after 2 h and 15 g/min of CO2, 235 bar, 55 °C (64.3 g THC/100 g of raw material and 4.6 g CBG/100 g of raw material). After another 2 h of extraction time, the yield of C... [more]
Food Production Scheduling: A Thorough Comparative Study between Optimization and Rule-Based Approaches
Maria E. Samouilidou, Georgios P. Georgiadis, Michael C. Georgiadis
August 3, 2023 (v1)
Keywords: food process industry, heuristics, MILP, Optimization, production scheduling
This work addresses the lot-sizing and production scheduling problem of multi-stage multi-product food industrial facilities. More specifically, the production scheduling problem of the semi-continuous yogurt production process, for two large-scale Greek dairy industries, is considered. Production scheduling decisions are made using two approaches: (i) an optimization approach and (ii) a rule-based approach, which are followed by a comparative study. An MILP model is applied for the optimization of short-term production scheduling of the two industries. Then, the same problems are solved using the commercial scheduling tool ScheduleProTM, which derives scheduling decisions using simulation-based techniques and empirical rules. It is concluded that both methods, despite having their advantages and disadvantages, are suitable for addressing complex food industrial scheduling problems. The optimization-based approach leads to better results in terms of operating cost reduction. On the oth... [more]
Fault Location of Distribution Network Based on Back Propagation Neural Network Optimization Algorithm
Chuan Zhou, Suying Gui, Yan Liu, Junpeng Ma, Hao Wang
August 3, 2023 (v1)
Keywords: BPNN, cloud genetic algorithm, fault diagnosis, Optimization
Research on fault diagnosis and positioning of the distribution network (DN) has always been an important research direction related to power supply safety performance. The back propagation neural network (BPNN) is a commonly used intelligent algorithm for fault location research in the DN. To improve the accuracy of dual fault diagnosis in the DN, this study optimizes BPNN by combining the genetic algorithm (GA) and cloud theory. The two types of BPNN before and after optimization are used for single fault and dual fault diagnosis of the DN, respectively. The experimental results show that the optimized BPNN has certain effectiveness and stability. The optimized BPNN requires 25.65 ms of runtime and 365 simulation steps. And in diagnosis and positioning of dual faults, the optimized BPNN exhibits a higher fault diagnosis rate, with an accuracy of 89%. In comparison to ROC curves, the optimized BPNN has a larger area under the curve and its curve is smoother. The results confirm that t... [more]
Removal of Organic Contaminants in Gas-to-Liquid (GTL) Process Water Using Adsorption on Activated Carbon Fibers (ACFs)
Roghayeh Yousef, Hazim Qiblawey, Muftah H. El-Naas
August 2, 2023 (v1)
Subject: Optimization
Keywords: activated carbon fibers, adsorption regeneration, GTL process, industrial water treatment, isotherm models, kinetics models, Optimization
Gas-To-Liquid (GTL) processing involves the conversion of natural gas to liquid hydrocarbons that are widely used in the chemical industry. In this process, the Fischer−Tropsch (F-T) approach is utilized and, as a result, wastewater is produced as a by-product. This wastewater commonly contains alcohols and acids as contaminants. Prior to discharge, the treatment of this wastewater is essential, and biological treatment is the common approach. However, this approach is not cost effective and poses various waste-related issues. Due to this, there is a need for a cost-effective treatment method. This study evaluated the adsorption performance of activated carbon fibers (ACFs) for the treatment of GTL wastewater. The ACF in this study exhibited a surface area of 1232.2 m2/g, which provided a significant area for the adsorption to take place. Response surface methodology (RSM) under central composite design was used to assess the effect of GTL wastewater’s pH, initial concentration and dos... [more]
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