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Showing records 27845 to 27869 of 43292. [First] Page: 1 1111 1112 1113 1114 1115 1116 1117 1118 1119 Last
Special Issue on “Processing and Conversion of Oil and Gas: Modeling, Control, Simulation and Optimization”
Jean Claude Assaf, Marina Al Daccache
February 27, 2023 (v1)
Petroleum is considered the black gold of the earth, but this treasure cannot be utilized without the usage of innovative and advanced technologies for its recovery and conversion [...]
Ameliorative Effect of Medicarpin on Scopolamine-Induced Cognitive Impairment in Mice
Jong Min Oh, Jong Eun Park, Seul-Ki Mun, Sung-Tae Yee, Hoon Kim
February 27, 2023 (v1)
Subject: Biosystems
Keywords: animal behavioral tests, medicarpin, scopolamine-induced cognitive impairment, Western blotting
The ameliorative effect of medicarpin (MC) was investigated by animal behavioral experiments such as Morris water maze (MWM), Y-maze, and passive avoidance test (PAT), using scopolamine-induced cognitively impaired mice. The scopolamine (5 mg/kg), donepezil (5 mg/kg), and MC (5 and 15 mg/kg) were administered by intraperitoneal injection at a volume of 0.3 mL. In the MWM, the escape latency times of MC-treated groups were significantly decreased compared with the scopolamine-treated negative control, and times spent in the platform zone of MC-treated groups were increased dose-dependently. In the Y-maze, the zone alternations of the MC-treated group were increased to the level of the donepezil-treated positive control. In the PAT, the crossing times of MC-treated groups were significantly higher than those of the negative control with dose-dependency. On the other hand, the monoamine oxidase (MAO)-A, MAO-B, and acetylcholinesterase (AChE) activities, relating to cognitive functions, in... [more]
Experimental and Numerical Investigation on Effects of Pin Diameter on Multi-Point Forming
Mahmut Tandogan, Omer Eyercioglu, Kaan Emre Engin
February 27, 2023 (v1)
Keywords: damage, forming, multi-point forming, pin diameter, stress distribution
Multi-point forming (MPF) is an advanced and flexible method to form sheet metal workpieces. Although there are studies investigating different aspects of this method, the studies on the effects of pin diameter on sheet and pin contact on MPF are insufficient. In this study, pins with diameters of 10, 12, and 14 mm were used to investigate the damage factor, effective stress distribution, and required forming loads of three forms of aluminum 1100 parts in finite element simulations. In addition, experimental works were conducted for the 12 mm pin and the forming loads and the thinning on the contact points of pin and formed sheet metal parts were compared with the simulations. The 14 mm pin forming provided the highest effective stress distributions and the damage factors of 0.448, 0.770, and 0.329 were obtained for form1, form2, and form3, respectively. The percentage errors between experimental works and simulations using 12 mm pin forming were calculated as 7.4, 5.1, and 2.4% for al... [more]
A Review on Solar Chimneys: From Natural Convection Fundamentals to Thermohydraulic Best-Performance Proposals
Blas Zamora
February 27, 2023 (v1)
Keywords: best-performance behavior, heat transfer enhancement, natural ventilation, numerical modeling, passive solar design, solar chimney, Trombe wall
This work presents an overview of (passive) solar chimney research, from the natural convection fundamentals to the recent progress for achieving thermohydraulic best-performance. Solar chimneys are attractive because they contribute to increasing the efficiency in air conditioning processes for dwellings and buildings, and therefore also aid to reduction in greenhouse gas emissions. A wide number of works dealing with solar chimneys (and Trombe walls or similar) shape designs, as well as with the inclusion of obstacles for disturbing the airflow, is commented in detail. Several numerical simulation procedures used in the literature are specially discussed, and different recommendations are pointed out to be considered for the appropriate numerical simulation of the operating modes of a solar chimney. Investigations aiming for the best performance conditions (for both thermal, and dynamic or ventilation modes) deserve special attention.
A Novel Fault Detection Method Based on One-Dimension Convolutional Adversarial Autoencoder (1DAAE)
Jian Wang, Yakun Li, Zhiyan Han
February 27, 2023 (v1)
Keywords: autoencoder, convolutional layer, Fault Detection, Tennessee Eastman process, unsupervised learning
Fault detection is an important and demanding problem in industry. Recently, many researchers have addressed the use of deep learning architectures for fault detection applications such as an autoencoder. Traditional methods based on an autoencoder usually complete fault detection by comparing reconstruction errors, and ignore a lot of useful information about the distribution of latent variables. To deal with this problem, this paper proposes a novel unsupervised fault detection method named one-dimension convolutional adversarial autoencoder (1DAAE), which introduces two new ideas: one-dimension convolution layers for the encoder to obtain better features and the adversarial thought to impose the latent variable z to cluster into a prior distribution. The proposed method not only has powerful feature representation ability than the traditional autoencoder, but has also enhanced the discrimination ability by imposing a prior distribution of the latent variables to cluster. Then, two a... [more]
Research on Assembly Sequence Optimization Classification Method of Remanufacturing Parts Based on Different Precision Levels
Yongmao Xiao, Jincheng Zhou, Shixiong Xing, Xiaoyong Zhu
February 27, 2023 (v1)
Keywords: assembly sequence, combinatorial algorithm, engine, remanufacturing, selection matching
Aiming at resolving the problem of low assembly accuracy and the difficulty of guaranteeing assembly quality of remanufactured parts, an optimization classification method for the assembly sequence of remanufactured parts based on different accuracy levels is proposed. By studying the characteristics of recycled parts, based on the requirement that the quality of remanufactured products not be lower than that of the assembly quality of new products, the classification selection matching constraints of remanufactured parts are determined, and the classification selection matching optimization models of remanufactured parts with different precision levels is established. An algorithm combining particle swarm optimization and a genetic algorithm is proposed to solve the model and obtain the optimal assembly sequence. Taking the remanufacturing assembling of a 1.4 TGDI engine crank and a connecting rod mechanism as an example, the comparison of quality data shows that this method can effec... [more]
Review of CFD-DEM Modeling of Wet Fluidized Bed Granulation and Coating Processes
Yinqiang Song, Tuo Zhou, Ruiqi Bai, Man Zhang, Hairui Yang
February 27, 2023 (v1)
Keywords: CFD-DEM, coating, fluidized bed, granulation
Wet fluidized bed granulation and coating processes have been widely used in the pharmaceutical and food industries. The complex gas−solid flow coupled with heat and mass transfer in such processes made it hard to form complete control over the apparatuses. To serve better design, scaling-up, and optimization of granulators and coaters, the underlying micro-scale mechanisms must be clarified. Computational fluid dynamics coupled with the discrete element method (CFD-DEM) provides a useful tool to study in-depth the gas-solid hydrodynamics of the granulation and coating processes. This review firstly introduced the fundamental theory of CFD-DEM from governing equations, force calculation, and coupling schemes. Then the application of CFD-DEM in simulating wet fluidized bed granulation and coating was presented. Specifically, the research focus and the role of CFD-DEM in resolving issues were discussed. Finally, the outlook on the development of CFD-DEM in the context of granulation and... [more]
Geometallurgical Detailing of Plant Operation within Open-Pit Strategic Mine Planning
Aldo Quelopana, Javier Órdenes, Rodrigo Araya, Alessandro Navarra
February 27, 2023 (v1)
Keywords: geometallurgy, linear programming, metaheuristics, metallurgical plant, open-pit mine planning, Stochastic Optimization
Mineral and metallurgical processing are crucial within the mineral value chain. These processes involve several stages wherein comminution is arguably the most important due to its high energy consumption, and its impact on subsequent extractive processes. Several geological properties of the orebody impact the efficiency of mineral processing and extractive metallurgy; scholars have therefore proposed to deal with the uncertain ore feed in terms of grades and rock types, incorporating operational modes that represent different plant configurations that provide coordinated system-wide responses. Even though these studies offer insights into how mine planning impacts the ore fed into the plant, the simultaneous optimization of mine plan and metallurgical plant design has been limited by the existing stochastic mine planning algorithms, which have only limited support for detailing operational modes. The present work offers to fill this gap for open-pit mines through a computationally e... [more]
Molecular Dynamics Simulation of the Interfacial Structure and Differential Capacitance of [BMI+][PF6−] Ionic Liquids on MoS2 Electrode
Chenxuan Xu, Zhanpeng Xu, Yihai Wang, Junjie Yang, Honghui Chen, Qiuhua Liu, Gang Chen, Huachao Yang
February 27, 2023 (v1)
Keywords: differential capacitance, electric double-layer structure, ionic liquid, MoS2 electrode, supercapacitor
MoS2 nanomaterials and ionic liquids (ILs) have attracted tremendous interest as the prime electrodes and electrolytes of supercapacitors. However, the corresponding charge storage mechanisms have not yet been clearly understood. Herein, we study the molecular-level energy storage mechanisms of the MoS2 electrode in imidazolium ionic liquid ([BMI+][PF6−]) using molecular dynamics (MD) simulation. The electric double-layer (EDL) structures of MoS2 electrodes in [BMI+][PF6−] electrolytes are comprehensively studied in terms of number density, MD snapshots, separation coefficient, and ion-electrode interaction energy. Based on this, the electric potential and electric field distributions are calculated by integrating Poisson equations. Importantly, a bell-shaped differential capacitance profile is proposed, different from the U-shaped curve from the conventional Gouy−Chapman theory. Especially, it can be well reproduced by the differential charge density curve in the Helmholtz layer. This... [more]
Effect of Environmental Conditions on Strontium Adsorption by Red Soil Colloids in Southern China
Yang Shao, Yuanyuan Zhao, Min Luo, Guifang Zhao, Diandou Xu, Zhiming Liu, Lingling Ma
February 27, 2023 (v1)
Subject: Environment
Keywords: Adsorption, China, soil colloid, strontium (Sr2+)
The fate of radionuclides in the environment is attracting increased attention. The effect of various environmental effects on the adsorption behavior of the strontium ion (Sr2+) by red soil colloids in Southern China was studied by a series of batch experiments, and the adsorption mechanism was briefly investigated as well. With the increase in the solid−liquid ratio and the concentration of Sr2+, the adsorption efficiency increased gradually. The effect of pH and ionic strength on adsorption was strong, while temperature had little effect. The adsorption data fitted to the Langmuir model indicates that the process is monolayered and homogeneous. The thermodynamic parameters also show that the adsorption of Sr2+ on red soil colloids is a spontaneous and exothermic process. The aim of this work is to gain insight into the role of red soil colloids on the fate of radionuclides in the field.
Base-Level Fluctuation Controls on Migration of Delta Lobes: A Case Study from the Paleogene Shahejie Formation in the Huimin Depression, Bohai Bay Basin, NE China
Renchao Yang, Yang Li, Xuepeng Wu, Jianqiang Di, Junjian Zhang, Nils Lenhardt
February 27, 2023 (v1)
Keywords: base level fluctuations, Huimin Depression, lacustrine deltas, Paleogene, sequence stratigraphy
Sandbody distribution patterns and controls are the most important foundation for petroleum exploration and development, particularly in a lacustrine basin with rapid changes in the sedimentary environment. To provide sedimentologists and petroleum geologists around the world with an analogue for sandstone reservoir prediction, the sedimentary facies of the fourth member of the Shahejie Formation (Sha-4 Member) in the Huimin Depression of the Bohai Bay Basin were analyzed, and the sequence stratigraphic framework was established based on characteristics of spontaneous potential logs and lithology. According to the findings of this study, the Sha-4 Member’s sedimentary environment was dominated by delta front and shallow lake facies. Delta front sandbodies were discovered to retrograde before prograding again throughout the established profile. The Sha-4 Member in the Huimin Depression is divided into a third-order sequence (LSC1), which can be further divided into four fourth-order seq... [more]
Special Issue on “Progress in Food Processing in Section Food Processes”
Dariusz Dziki
February 27, 2023 (v1)
Food production is being confronted by numerous difficulties related to sustainability, food quality and security [...]
Effect of Roasting Hass Avocado Kernels on Nutritional Value and Volatile Compounds
Hala M. Bayomy, Eman S. Alamri, Mahmoud A. Rozan
February 27, 2023 (v1)
Subject: Biosystems
Keywords: GC-MS profile, Hass avocado kernels, nutritional value, roasting
Because of the lack of commercial food applications of Hass avocado (Persea americana Mill) kernel, which are a useful agricultural waste and a good source of bioactive compounds, this study investigated the influence of roasting on the chemical composition, antinutritional factors, antioxidant activity, colour, and GC-MS profile in avocado kernels after roasting at 180 °C for 30 min. The nutritional data revealed a significant increase (p < 0.05) in the oil extract, crude fibre, total phenolic compounds, Ca, K, P, Na, Zn, browning index, and redness/greenness after roasting. Conversely, a significant decrease (p < 0.05) was noticed in crude protein, total flavonoids, Fe, antinutrients, lightness, and yellowness/blueness after roasting. The 94 volatile compounds separated by GC-MS included 51 compounds from raw Hass kernels and 65 compounds from roasted kernels. The identified compounds constituted 96.21% and 93.25% in raw and roasted Hass kernels, respectively. The most compound... [more]
In-Situ Hydrothermal Synthesis of Ag3PO4/g-C3N4 Nanocomposites and Their Photocatalytic Decomposition of Sulfapyridine under Visible Light
Ke Li, Miaomiao Chen, Lei Chen, Songying Zhao, Wencong Xue, Zixuan Han, Yanchao Han, Fuguo Zhang, Yu Yan, Yanhong Dong
February 27, 2023 (v1)
Subject: Materials
Keywords: Ag3PO4, g-C3N4, photocatalysis, sulfapyridine, visible light
Highly efficient visible-light-driven heterogeneous photocatalyst Ag3PO4/g-C3N4 with different weight ratios from Ag3PO4 to g-C3N4 were synthesized by a facile in situ hydrothermal method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FTIR), photoluminescence spectra (PL), UV−vis diffuse reflectance spectra (UV-Vis), and electrochemical impedance spectra (EIS). Under visible light irradiation, Ag3PO4/g-C3N4 showed very excellent photocatalytic activity for sulfapyridine (SP) which is one of the widely used sulfonamide antibiotics. When the ratio from Ag3PO4 to g-C3N4 was 1:2, the degradation rate of SP at 120 min was found to be 94.1%, which was superior to that of pure Ag3PO4 and pure g-C3N4. Based on the experimental results, the possible enhanced photocatalytic mechanism of Ag3PO4/g-C3N4 was proposed.
Influence of Prefermentative Cold Maceration on the Chemical and Sensory Properties of Red Wines Produced in Warm Climates
Cristina Lasanta, Cristina Cejudo, Juan Gómez, Ildefonso Caro
February 27, 2023 (v1)
Subject: Biosystems
Keywords: bottle aging, prefermentative cold maceration, red wine, warm climate, wine aromatic profile
Red wines produced in warm climates generally possess a lower content of phenolic compounds and color structure than those produced in colder climates, which hinders bottle evolution. To improve these properties, cold maceration could be a useful procedure. To study the effect of this technique, Tempranillo, Merlot and Syrah grape varieties cultivated in the Jerez area (Southwest Spain) were cold macerated at 4 °C for ten days before alcoholic fermentation. Their composition and characteristics compared to the directly fermented control grapes were analyzed for phenolic content, color, volatile compounds, and sensory properties. It has been verified that phenolic content increased by around 10% during the treatment, which was maintained after the alcohol fermentation, along with an increase in color intensity and aromatic profile. This modification on the composition provided better scores for appearance, aroma intensity, and aroma quality in sensory analysis. The evolution of all stud... [more]
Determination of Electrogenic Potential and Removal of Organic Matter from Industrial Coffee Wastewater Using a Native Community in a Non-Conventional Microbial Fuel Cell
Santiago Erazo, Lina María Agudelo-Escobar
February 27, 2023 (v1)
Subject: Biosystems
Keywords: agro-industrial wastewater, coffee waste, electroactive, MFC, microbial fuel cell, native microbial community
Microbial fuel cells (MFCs) are an alternative to conventional wastewater treatments that allow for the removal of organic matter and cogeneration of electrical energy, taking advantage of the oxidation−reduction metabolism of organic compounds conducted by microorganisms. In this study, the electrogenic potential and the capacity for the reduction of the organic matter of native microbial communities in wastewater from the wet processing of coffee were evaluated using open-cathode MFCs. To determine the electrogenic potential, a factorial experimental design was proposed in which the origin of the residual water and the source of the inoculum were evaluated as factors. The MFCs operated for 21 days in both open-circuit and closed-circuit operation modes. Voltage records, current determinations, and chemical oxygen demand (COD) analyses were used to establish the power reached in the electrochemical system and the degree of the decontamination of the wastewater. During the MFC operatio... [more]
Development of Experimental Techniques for the Phase Equilibrium Study in the Pb-Fe-O-S-Si System Involving Gas, Slag, Matte, Lead Metal and Tridymite Phases
Taufiq Hidayat, Ata Fallah-Mehrjardi, Maksym Shevchenko, Peter C. Hayes, Evgueni Jak
February 27, 2023 (v1)
Subject: Environment
Keywords: lead matte, lead metal, lead slag, phase equilibria experiments
Present society challenges, including metal scarcity, recycling, and environmental restrictions, resulted in the increased complexity and variability of metallurgical feed streams. Metallurgical processes involving complex lead and copper-containing slag and matte phases are now commonly used in response. Optimization of existing and development of new metallurgical processes require fundamental information on slag−matte phase equilibrium. Development of the experimental methodology for the characterization of slag−matte phase equilibrium is presented in the paper. Following a detailed analysis of the potential reaction pathways, experimental techniques have been developed that enable accurate measurement of slag−matte phase equilibrium in the Pb-Fe-O-S-Si system. The application of the techniques has been demonstrated for two important sets of conditions: (i) Condensed phase equilibrium for the slag−matte−metal−tridymite subsystem; and (ii) Gas−slag−matte−tridymite equilibrium at fixe... [more]
Robustness Evaluation Process for Scheduling under Uncertainties
Sara Himmiche, Pascale Marangé, Alexis Aubry, Jean-François Pétin
February 27, 2023 (v1)
Keywords: decision making, discrete event systems, Industry 4.0, production scheduling, robustness evaluation, uncertainties
Scheduling production is an important decision issue in the manufacturing domain. With the advent of the era of Industry 4.0, the basic generation of schedules becomes no longer sufficient to face the new constraints of flexibility and agility that characterize the new architecture of production systems. In this context, schedules must take into account an increasingly disrupted environment while maintaining a good performance level. This paper contributes to the identified field of smart manufacturing scheduling by proposing a complete process for assessing the robustness of schedule solutions: i.e., its ability to resist to uncertainties. This process focuses on helping the decision maker in choosing the best scheduling strategy to be implemented. It aims at considering the impact of uncertainties on the robustness performance of predictive schedules. Moreover, it is assumed that data upcoming from connected workshops are available, such that uncertainties can be identified and model... [more]
Enzymatic Hydrolysis of Complex Carbohydrates and the Mucus in a Mathematical Model of a Gut Reactor
Thulasi Jegatheesan, Arun S. Moorthy, Hermann J. Eberl
February 27, 2023 (v1)
Subject: Biosystems
Keywords: chemostat model, compartments, dietary fiber, gut model, hydrolysis, mucins
The human gut microbiota rely on complex carbohydrates for energy and growth, particularly dietary fiber and host-produced mucins. These complex carbohydrates must first be hydrolysed by certain microbial groups to enable cross-feeding by the gut microbial community. We consider a mathematical model of the enzymatic hydrolysis of complex carbohydrates into monomers by a microbial species. The resulting monomers are subsequently digested by the microbial species for growth. We first consider the microbial species in a single compartment continuous stirred-tank reactor where dietary fiber is the only available substrate. A two compartment configuration in which a side compartment connected by diffusion is also studied. The side compartment is taken to be the mucus layer of the human colon, providing refuge from washout and an additional source of complex carbohydrate in the form of mucins. The two models are studied using stability analysis, numerical exploration, and sensitivity analysi... [more]
A Review of Real-Time Fault Diagnosis Methods for Industrial Smart Manufacturing
Wenhao Yan, Jing Wang, Shan Lu, Meng Zhou, Xin Peng
February 27, 2023 (v1)
Keywords: AI, industrial process monitoring, industrial smart manufacturing, machine condition monitoring, RTFD
In the era of Industry 4.0, highly complex production equipment is becoming increasingly integrated and intelligent, posing new challenges for data-driven process monitoring and fault diagnosis. Technologies such as IIoT, CPS, and AI are seeing increasing use in modern industrial smart manufacturing. Cloud computing and big data storage greatly facilitate the processing and management of industrial information flow, which helps the development of real-time fault diagnosis (RTFD) technology. This paper provides a comprehensive review of the latest RTFD technologies in the field of industrial process monitoring and machine condition monitoring. The RTFD process is introduced in detail, starting with the data acquisition process. The current RTFD methods are divided into methods based on independent feature extraction, methods based on “end-to-end” neural networks, and methods based on qualitative knowledge reasoning from a new perspective. In addition, this paper discusses the challenges... [more]
Dataset of 3β-Corner and 3β-Corner-like Structures
Vladimir R. Rudnev, Liudmila I. Kulikova, Kirill S. Nikolsky, Denis V. Petrovsky, Alexander A. Stepanov, Kristina A. Malsagova, Anna L. Kaysheva
February 27, 2023 (v1)
Subject: Biosystems
Keywords: 3β-corner, 3β-corner-like structure, dataset, structural motif of a protein
The study is devoted to the creation of a dataset of protein structural motifs of the 3β-corner type. The relevance and importance of creating a dataset of 3β-corners is determined by the fact that this structure can be an embryo or a ready-made structural block in the process of protein folding, and can also act as an independent object of research in the field of structural biology. The dataset also contains 3β-corner-like structures that are geometrically similar to 3β-corners. The dataset consists of 45,896 structures. For each motif, its characteristics are presented: the name of the protein in which the 3β-corner is recognized, the method and resolution of the protein structure, the coordinates of localization in the protein, the secondary structure of the amino acid sequence, the gyration radius, the solvent-accessible area, and the composition of the elements of the secondary structure. The dataset will allow a comprehensive study of structures on a large scale and advance the... [more]
Study on the Shadow Effect of the Stress Field around a Deep-Hole Hydraulic-Fracturing Top-Cutting Borehole and Process Optimization
Shuanlin Wang, Jianqiao Luo
February 27, 2023 (v1)
Keywords: fluid–solid coupling, fracture mechanics, prescribed hydraulic fracturing, stress shadow effect
The clean utilization and green development of coal resources have become a research focus in recent years. Underground hydraulic fracturing technology in coal mines has been widely used in roof pressure relief, top coal pre-splitting, gas drainage, roadway pressure relief and goaf disaster prevention. Different in situ stress types cause great differences in the stress field around the boreholes, the critical pressure of the fracture initiation, and the direction of the fracture expansion trend; in addition, the stress shadow effect generated by the superposition of stress fields between boreholes relatively close together has a mutual coupling effect on the evolution of the stress field, the development of the plastic zone, and the crack propagation of the rock mass. Therefore, an effective method to solve the problem is to establish a mechanical model of hydraulic fracturing in boreholes for theoretical calculation, determine the influence mechanism of the crack shadow effect, and d... [more]
Optimization of an Indoor DWC Hydroponic Lettuce Production System to Generate a Low N and P Content Wastewater
Luis M. I. Aires, Kirill Ispolnov, Tomás R. Luz, Helena Pala, Judite S. Vieira
February 27, 2023 (v1)
Subject: Optimization
Keywords: daily light integral, deep-water culture, Lactuca sativa L., light-use efficiency, N and P removal, water-use efficiency
Hydroponic production raises economic and environmental issues related to the treatment, recovery or disposal of hydroponic wastewater, which can be rich in eutrophication-related nutrients, nitrogen (N) and phosphorus (P). Little focus has been put on the influence of the growth conditions on the N and P content in hydroponic wastewater, which is of uttermost importance when it is intended to reuse the wastewater for irrigation or other purposes with reduced impact on the environment. This study aimed to optimize an indoor non-recirculating deep-water culture (DWC) hydroponic system for lettuce (Lactuca sativa L. var. crispa) production, in terms of daily light integral (DLI) and volume of nutrient solution (NS) per plant, to maximize both the biomass production and the N and P removal, allowing for the wastewater to meet the criteria established for reusing in irrigation and minimizing the eutrophication impacts. A small-scale DWC hydroponic system with a fluorescent light fixture wa... [more]
Reuse of Carbon Fibers and a Mechanically Recycled CFRP as Rod-like Fillers for New Composites: Optimization and Process Development
José Antonio Butenegro, Mohsen Bahrami, Miguel Ángel Martínez, Juana Abenojar
February 27, 2023 (v1)
Subject: Optimization
Keywords: carbon fiber reinforced polymers, polymer composites, properties optimization, recycling processes
The rising amount of carbon fiber reinforced polymer (CFRP) composite waste requires new processes for reintroducing waste into the production cycle. In the present research, the objective is the design and study of a reuse process for carbon fibers and CFRP by mechanical recycling consisting of length and width reduction, obtaining rods and reintegrating them as fillers into a polymeric matrix. Preliminary studies are carried out with continuous and discontinuous unidirectional fibers of various lengths. The processing conditions are then optimized, including the length of the reinforcement, the need for a plasma surface treatment and/or for resin post-curing. The resin is thermally characterized by differential scanning calorimetry (DSC), while the composites are mechanically characterized by tensile strength tests, completed by a factorial design. In addition, the composites tested are observed by scanning electron microscopy (SEM) to study the fracture mechanics. Optimal processing... [more]
Optimization and Prediction of Stability of Emulsified Liquid Membrane (ELM): Artificial Neural Network
Meriem Zamouche, Hichem Tahraoui, Zakaria Laggoun, Sabrina Mechati, Rayene Chemchmi, Muhammad Imran Kanjal, Abdeltif Amrane, Amina Hadadi, Lotfi Mouni
February 27, 2023 (v1)
Keywords: artificial neural network, emulsification time, emulsified liquid membrane (ELM), Span 80, stability, stirring speed
In this work, the emulsified liquid membrane (ELM) extraction process was studied as a technique for separating different pollutants from an aqueous solution. The emulsified liquid membrane used consisted of Sorbitan mono-oleate (Span 80) as a surfactant with n-hexane (C6H14) as a diluent; the internal phase used was nitric acid (HNO3). The major constraint in the implementation of the extraction process by an emulsified liquid membrane (ELM) is the stability of the emulsion. However, this study focused first on controlling the stability of the emulsion by optimizing many operational factors, which have a direct impact on the stability of the membrane. Among the important parameters that cause membrane breakage, the surfactant concentration, the emulsification time, and the stirring speed were demonstrated. The optimization results obtained showed that the rupture rate (Tr) decreased until reaching a minimum value of 0.07% at 2% of weight/weight of Span 80 concentration with an emulsif... [more]
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