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Sequential Processing Using Supercritical Carbon Dioxide and High-Intensity Ultrasound in Sunflower Protein Flour Production: Nutritional Value, Microstructure, and Technological Functionality
Mariana Pacífico dos Santos Friolli, Eric Keven Silva, Janaíne Chaves, Marcos Fellipe da Silva, Rosana Goldbeck, Fabiana Andrea Barrera Galland, Maria Teresa Bertoldo Pacheco
September 21, 2023 (v1)
Subject: Materials
Keywords: food technology, innovative technologies, plant protein, plant-based ingredient, sunflower seed
Sunflowers are among the world’s most widely cultivated oilseeds with an interesting nutritional composition. A biomass composed mainly of carbohydrates, fibers, and proteins is generated from sunflower oil production. In this context, the objective of this study was to investigate the application of emerging technologies to sunflower biomass to obtain an edible protein-rich flour with the potential to be exploited in the food industry. The effects of the optimized conditions for the sequential processing of sunflower meal using supercritical carbon dioxide (SCO2) and high-intensity ultrasound (HIUS) were investigated. The protein structure was preserved even after the application of HIUS to the flour as verified through differential scanning calorimetry (DSC) and the electrophoresis curves. The fact that the HIUS treatment did not modify the protein structure demonstrates that this emerging technology could be incorporated into the processing chain of this new food ingredient (sunflow... [more]
Comparison between Air-Exposed and Underground Thermal Energy Storage for Solar Cooling Applications
Juan Ríos-Arriola, Nicolás Velázquez-Limón, Jesús Armando Aguilar-Jiménez, Saúl Islas, Juan Daniel López-Sánchez, Francisco Javier Caballero-Talamantes, José Armando Corona-Sánchez, Cristian Ascención Cásares-De la Torre
September 21, 2023 (v1)
Keywords: solar thermal energy storage, thermal energy storage tank, underground thermal energy storage, UTES
Solar energy is one of the main alternatives for the decarbonization of the electricity sector and the reduction of the existing energy deficit in some regions of the world. However, one of its main limitations lies in its storage, since this energy source is intermittent. This paper evaluates the potential of an underground thermal energy storage tank supplied by solar thermal collectors to provide hot water for the activation of a single-effect absorption cooling system. A simulator was developed in TRNSYS 17 software. Experimentally on-site measured data of soil temperature were used in order to increase the accuracy of the simulation. The results show that the underground tank reduces thermal energy losses by 27.6% during the entire hot period compared with the air-exposed tank. The electrical energy savings due to the reduction in pumping time during the entire hot period was 639 kWh, which represents 23.6% of the electrical energy consumption of the solar collector pump. It can b... [more]
Numerical Optimization Study of the Resistance Coefficient of U-Shaped Air Distributor
Zhijing Wu, Jinfeng Wang, Jing Xie
September 21, 2023 (v1)
Subject: Optimization
Keywords: air distributor, flow channel structure, orthogonal test design, pressure loss, resistance coefficient
In this paper, the optimization of the flow channel structure of the U-shaped air distributor is proposed. Fluent meshing was used to mesh the multipatch meshing of the original model of the grid air distributor, and then the CFD numerical simulation was carried out by using Fluent 2022R1 to obtain the internal air flow state of the air distributor flow channel. Through the orthogonal experimental design and a comprehensive analysis method, the optimal size structure for resistance performance is obtained as S = 60 mm, RL = 125 mm, L = 160 mm, D = 100 mm, the resistance coefficient of the new structure as 1.375, and the pressure loss as 56.87 Pa, by using 3D modeling software (SOLIDWORKS 2015) and Fluent. Compared with the initial scheme, the resistance coefficient and pressure loss are reduced by 3.03% and 6.29%, respectively. To summarize, the research in this paper offers a substantial contribution to the realm of energy conservation and emission abatement in ship air conditioning s... [more]
Method for Dynamic Prediction of Oxygen Demand in Steelmaking Process Based on BOF Technology
Kaitian Zhang, Zhong Zheng, Liu Zhang, Yu Liu, Sujun Chen
September 21, 2023 (v1)
Keywords: basic oxygen furnace mode, Big Data, dynamic prediction, oxygen demand, steelmaking
Oxygen is an important energy medium in the steelmaking process. The accurate dynamic prediction of oxygen demand is needed to guarantee molten steel quality, improve the production rhythm, and promote the collaborative optimization of production and energy. In this work, a analysis of the mechanism and of industrial big data was undertaken, and we found that the characteristic factors of Basic Oxygen Furnace (BOF) oxygen consumption were different in different modes, such as duplex dephosphorization, duplex decarbonization, and the traditional mode. Based on this, a dynamic-prediction modeling method for BOF oxygen demand considering mode classification is proposed. According to the characteristics of BOF production organization, a control module based on dynamic adaptions of the production plan was researched to realize the recalculation of the model predictions. A simulation test on industrial data revealed that the average relative error of the model in each BOF mode was less than... [more]
Monitoring and Characterizing the Flame State of a Bluff-Body Stabilized Burner by Electrical Capacitance Tomography
Liuyong Chang, Boxuan Cui, Chenglin Zhang, Zheng Xu, Guangze Li, Longfei Chen
September 21, 2023 (v1)
Keywords: electrical capacitance tomography, flame flashback, flame liftoff, flame state, flame state index
Unstable combustion phenomena such as flame flashback, flame liftoff, extinction and blowout frequently take place during the operation of the bluff-body stabilized burner. Therefore, flame state monitoring is necessary for the safe operation of the bluff-body stabilized burner. In the present study, an electrical capacitance tomography (ECT) system was deployed to detect the permittivity distribution in the premixing channel and further characterize the flame states of stabilization, flashback, liftoff, extinction and blowout. A calderon-based reconstruction method was modified to reconstruct the permittivity distribution in the annular premixing channel. The detection results indicate that the permittivity in the premixing channel increases steeply when the flame flashback takes place and decreases obviously when the flame lifts off from the combustor rim. Based on the varied permittivity distribution at different flame states, a flame state index was proposed to characterize the fla... [more]
An Investigation into the Potential of a Penicillium Commune Strain to Eliminate Aromatic Compounds
Maria Gerginova, Katya Stoyanova, Nadejda Peneva, Ivayla Dincheva, Zlatka Alexieva
September 21, 2023 (v1)
Subject: Biosystems
Keywords: biodegradation, DNA sequencing, fungi, GC–MS, oxiganases, PAHs
The quantity of industrially polluted waters is increasing everywhere, of which a significant part is occupied by a number of mono- and poly-aromatic compounds. Toxins enter the soil, sewage, and clean water by mixing with or seeping into them from industrial wastewater. By using 18S RNA and ITS sequences, the Penicillium commune AL5 strain that was isolated from Antarctic soil was identified. This study is dedicated to exploring its capacity to metabolize hazardous aromatic compounds. The strain showed very good potential in the degradation of hydroxylated monophenols and possessed exceptional abilities in terms of resorcinol degradation. The strain’s ability to metabolize 0.3 g/L of p-cresol at 10 °C is notable. The strain is also capable of metabolizing LMW PAHs (naphthalene, anthracene, and phenanthrene) and eliminating all three tested compounds under 23 °C, respectively, 77.5%, 93.8%, and 75.1%. At 10 °C, the process slowed down, but the degradation of naphthalene continued to be... [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]
Biodegradable Composite Film of Brewers’ Spent Grain and Poly(Vinyl Alcohol)
Lilian Lin, Sarah Mirkin, Heon E. Park
September 21, 2023 (v1)
Keywords: biodegradable composite film, brewers’ spent grain, food waste, glycerol, hexamethoxymethylmelamine (HMMM), mechanical properties, moisture uptake, mulch film, poly(vinyl alcohol), tensile tests, universal test machine, waste upcycling
Plastic pollution and food waste are two pressing global challenges that require immediate attention and innovative solutions. In this study, we address these challenges by upcycling brewers’ spent grain (BSG) into biodegradable composite films. BSG, a by-product of the beer brewing process, is commonly discarded in landfills or used as animal feed. By utilizing BSG as a raw material for biodegradable films, we simultaneously reduce waste and decrease plastic pollution. To create the composite films, we employed poly(vinyl alcohol) (PVA) and glycerol as binder materials, along with hexamethoxymethylmelamine (HMMM) as a water-repelling agent. By varying the ratios of these components, we investigated the effects on film properties. Our characterization included assessing moisture uptake and tensile properties. The results revealed that the practical BSG content in the films was 20−60 wt%. Films with this composition exhibited a balance between moisture absorption and mechanical strength... [more]
Experimental Study of Sound Pressure Level in Hydraulic Power Unit with External Gear Pump
Alexander Mitov, Krasimir Nedelchev, Ivan Kralov
September 21, 2023 (v1)
Keywords: experimental study, external gear pump, sound pressure level
The article presents the results of an experimental study of the sound pressure level (SPL) caused by a hydraulic power unit with an external gear pump. The study was carried out with a specially developed laboratory experimental setup based on a common architecture used in hydraulic power units. Both the hydraulic system and the measuring equipment used are described in detail. The design of the experimental studies performed, including two main configurations with specific parameters regarding the operating modes of the system, is presented. The experimental results obtained are presented in the form of magnitude frequency responses which are compared in accordance with the experiment design. An analysis of the results obtained is performed using various quantitative indicators. For specific operating modes, parametric models were derived by approximation of the experimental data. The resulting models can serve in future work to reduce the SPL by passive or active means (e.g., freque... [more]
A Comprehensive Asset Evaluation Method for Oil and Gas Projects
Muzhen Zhang, Ailin Jia, Zhanxiang Lei, Gang Lei
September 21, 2023 (v1)
Subject: Optimization
Keywords: asset comprehensive evaluation method, asset grading and ranking, cloud model, linear weighted, new oil and gas field project
The rapid and accurate evaluation of oil and gas assets, specifically for new development projects, poses a significant challenge due to the various project types, limited data availability, brief periods for assessment and decision making, and constraints arising from varying contractual and taxation conditions, political stability, and societal factors. This study leverages the grading standards of the evaluation index system for new oil and gas field development projects, along with relevant mathematical theories and methods for project evaluation and optimization. We developed an asset evaluation approach for new oil and gas projects by analyzing the assets of six new oil and gas field development projects in Brazil. This analysis resulted in the grading and ranking of new projects, and we tested and demonstrated four asset optimization techniques. After a comparative analysis with conventional evaluation results, we established an oil and gas project asset optimization approach ce... [more]
The Fermentation of a Marine Probiotic Bacterium on Low-Cost Media Formulated with Industrial Fish Gelatin Waterstreams and Collagen Hydrolysates
José Antonio Vázquez, Adrián Pedreira, Iván Salmerón, Dyah H. Wardhani, Jesus Valcarcel
September 21, 2023 (v1)
Subject: Environment
Keywords: bioconversion, collagen hydrolysates, gelatin effluents, marine probiotic bacteria, Phaeobacter sp. DIFR 27-4, Renewable and Sustainable Energy
Chemical effluents generated by the isolation of fish gelatin and collagen hydrolysates produced from the enzyme proteolysis of skin wastes are protein-rich substrates that could be used as nutrients in bacterial bioprocessing. In this study, the suitability of such nutrients in supporting the growth of a marine probiotic bacterium, Phaeobacter sp. DIFR 27-4, was studied. Both gelatin effluents and collagen hydrolysates were obtained from the skins of shark, tuna, salmon and turbot. The chemical composition of the substrates included the complete presence of all quantified amino acids. Low-cost marine culture media were formulated with these protein materials alongside a very low concentration of yeast extract and marine water. In batch cultures with gelatin effluents, the growth rates of the strain DIFR 27-4 were somewhat lower than those found in the control marine commercial media. In the case of the hydrolysates, the bacterial production of biomass was similar or higher than that o... [more]
Removal of Fluoroquinolone Antibiotics by Chitosan−Magnetite from Aqueous: Single and Binary Adsorption
Quy M. Bui, Tung Q. Vu, Xuan T. Vuong, Vinh D. Nguyen, Linh T. N. Nguyen, Ha T. Le, Hoa T. H. Nguyen, Van Phuoc Nguyen
September 21, 2023 (v1)
Subject: Biosystems
Keywords: Adsorption, binary, chitosan, ciprofloxacin, levofloxacin, magnetite
In this research, chitosan−magnetite composites (CS-MNPs) were successfully synthesized using a rapid and easy technique. The materials were characterized by FTIR, XRD, EDX, TEM, VSM, and BET methods. The removal of the antibiotics ciprofloxacin (CFX) and levofloxacin (LFX) from aqueous solutions by CS-MNPs adsorbent was investigated. The influencing factors in a single adsorption system were studied, including pH (1−11), initial concentration (2.5−15.0 mg/L), contact time (0−120 min), and adsorbent dosage (5−50 mg/L). The experiment data were analyzed by pseudo-first-order and pseudo-second-order kinetic models. The adsorption isotherms were studied by fitting the experimental data to the Langmuir, Freundlich, and Temkin models. The results indicated that the adsorption of CFX and LFX antibiotics was consistent with the pseudo-second-order kinetics model, the Langmuir isotherm model. Binary adsorption systems (CFX: LFX) with concentration ratios of 1:0, 1:0.5, 1:1.0, 1:1.5, and 1:2.0... [more]
Research on the Stability of the Spacer Fluid Interface in Dual-Layer Pipe Dual-Gradient Drilling
Guorong Wang, Xiaolei Li, Lin Zhong, Zhiyu Lv
September 21, 2023 (v1)
Keywords: dual-layer pipe dual-gradient drilling, pressure system, spacer fluid interface, stability
Dual-layer pipe dual-gradient drilling technology is an emerging technology for solving the problem of the narrow safety density window in deepwater drilling. The unstable spacer fluid interface in this technology directly affects the dual-gradient pressure system in the annulus, causing changes in the drilling mud performance and affecting the control of bottom hole pressure and rock removal with drilling mud. Therefore, the key to the stable operation of dual-layer pipe dual-gradient drilling technology is to maintain the stability of the spacer fluid interface. Based on this, a seawater-spacer fluid-drilling mud annular flow model was established in this study, with a bottom hole pressure control step of 0.2 MPa, and the spacer fluid height after a single control was used as the evaluation index to study the influence of annular flow velocity, the spacer fluid properties, and the drill string rotation speed on the stability of the spacer fluid interface. The results show that in the... [more]
Experimental Study on Convection and Heat Conduction Heating of an Air-Conditioned Bed System under Winter Lunch Break Mode
Junjie Jin, Peiyao Duan, Yu Liu, Honglin Chen, Tingting Yu
September 21, 2023 (v1)
Keywords: air-conditioned bed system, convection heating, energy conservation, heat conduction heating, thermal comfort
In this paper, an experimental study of a system for heating an air-conditioned bed during a 2 h lunch was carried out. The results show that the power consumption of heat conduction heating was only 0.34 kW·h and that the average heat dissipation was 81.3 W, while the power consumption of convection heating was 1.43 kW·h, accompanied by an average heat dissipation of 748.7 W. Regardless of the power consumption or the heat dissipation, the convection heating was significantly higher than the heat conduction heating. As a result, the room air temperature increased from 12.3 °C to 17.3 °C under convection heating, but only increased from 14.4 °C to 15.2 °C under heat conduction heating. The study results indicate that when using heat conduction heating, water temperatures in the range of 38~40 °C could meet the thermal comfort needs of the human body; however, a higher temperature range was required when using convection heating. In contrast, the grade of the hot water required for heat... [more]
Role of Biosynthesized Silver Nanoparticles with Trigonella foenum-graecum Seeds in Wastewater Treatment
Manal A. Awad, Promy Virk, Awatif A. Hendi, Khalid Mustafa Ortashi, Najla AlMasoud, Taghrid S. Alomar
September 21, 2023 (v1)
Subject: Materials
Keywords: green synthesis, photo degradation, sewage effluent, silver nanoparticles, Trigonella foenum-graecum seed, wastewater treatment
As the human population continues to escalate, its requirement for clean water is also increasing. This has resulted in an increased dependency on wastewater effluent to maintain the base flow of urban streams, especially in water-stressed regions. The present study reports the synthesis of AgNPs with green credentials using an aqueous extract of Trigonella foenum-graecum seeds. The observance of surface plasmon resonance (SPR) with UV−Vis spectrophotometry confirmed the presence of spherical/oblong particles with a mean diameter of 43.8 nm and low polydispersity index (PDI) of 0.391 measured by transmission electron microscopy (TEM) and DLS (dynamic light scattering) technique, respectively. The elemental map of AgNPs was demonstrated with energy-dispersive spectroscopy (EDS) and the constituent functional groups were identified by the FTIR spectra, which were similar to the bulk seed extract with a slight shift in the pattern. The emission spectrum of nanoparticles was recorded for t... [more]
The Characteristics of Fracturing Fluid Distribution after Fracturing and Shut-In Time Optimization in Unconventional Reservoirs Using NMR
Xin Huang, Lei Wang, Nan Wang, Ming Li, Shuangliang Wu, Qun Ding, Shucan Xu, Zhilin Tuo, Wenqiang Yu
September 21, 2023 (v1)
Subject: Optimization
Keywords: distribution characteristics, fracturing fluid, NMR, post-fracturing shut-in, shut-in duration, unconventional reservoir
Post-fracturing shut-in, as an important means of improving the energy efficiency of fracturing fluid, has been widely used in the development process of unconventional reservoirs. The determination of the shut-in duration is key to the effectiveness of shut-in measures. However, the distribution characteristics of the fracturing fluid during the post-fracturing shut-in period in unconventional reservoirs, such as the Chang 7 reservoir, were not clear, and the shut-in duration needed further optimization. Therefore, this paper employed low-field nuclear magnetic resonance (NMR) technology to study the distribution characteristics of the fracturing fluid during the post-fracturing shut-in period in unconventional reservoirs and optimized the shut-in duration. The study showed that the Chang 7 reservoir had a complex pore structure and relatively low porosity and permeability. During the shut-in process, the filtrate was distributed in pore throats with radii ranging from 0.0012 μm to 0.... [more]
Study on the Influence of Fluid Pulsation on Hydraulic Impactor Performance in Drilling Engineering
Haibo Cui, Wei Li, Hongbing Xiao, Yufei Wang, Wei Chen, Wenting Liu
September 21, 2023 (v1)
Keywords: bit footage, drilling efficiency, hydraulic impactor, positive displacement motor, rate of penetration
The combination of the hydraulic impactor and positive displacement motor (PDM) is becoming more and more popular in drilling engineering. However, the negatives of the PDM on the impactor cannot be ignored. To improve the performance of the technique, the influence of fluid pulsation from the PDM on the hydraulic impactor was studied first; then, the structure of the impactor was optimized to improve its impact force; finally, field tests were carried out in 2 wells in the shallow formation. The results indicate that the fluid fluctuation generated in the PDM can restrain the performance of the impactor, and that the impact force can be increased by 24.4% to 28.6% through the optimization of design. Field tests show that this technique can further improve the drilling efficiency and rotating stability of the polycrystalline diamond compact bit, and that the rate of penetration and bit footage increase by 32.5% and 34.6%, respectively. In the study, the effect of inlet fluid fluctuatio... [more]
Liquid−Liquid Two-Phase Flow and Size Prediction of Slug Droplets in Microchannels
Wei Du, Yingfeng Duan, Lina Wang, Dayu Liu
September 21, 2023 (v1)
Keywords: downstream orifice, droplet, microchannels, size prediction, two-phase flow
The liquid−liquid two-phase flow and size prediction of slug droplets in flow-focusing microchannels with different downstream orifice sizes were investigated experimentally. Aqueous solution of 50%-glycerol and mineral oil with 4 wt.% surfactant sorbitanlauric acid ester (Span 20) were used as the dispersed and continuous phases, respectively. Three characteristic flow patterns were identified: slug flow, dripping flow, and jetting flow. The slug flow region decreased but the jetting flow region increased with the decrease in the size of the channel orifice. Afterwards, the universal flow pattern maps of the liquid−liquid two-phase in three microchannels were obtained based on dimensionless analysis. Furthermore, two slug droplet formation regions were found: when φ−1Cac < 0.01, the droplet formation was mainly driven by the squeezing force Fp, while when φ−1Cac > 0.01, both the squeezing force Fp and shear force Fτ contributed to droplet formation. Additionally, the prediction correl... [more]
Low-Power Very-Large-Scale Integration Implementation of Fault-Tolerant Parallel Real Fast Fourier Transform Architectures Using Error Correction Codes and Algorithm-Based Fault-Tolerant Techniques
M. Kalpana Chowdary, Rajasekhar Turaka, Bayan Alabduallah, Mudassir Khan, J. Chinna Babu, Ajmeera Kiran
September 21, 2023 (v1)
Keywords: ABFT, ASIC, FFT, FPGA, soft errors
As technology advances, electronic circuits are more vulnerable to errors. Soft errors are one among them that causes the degradation of a circuit’s reliability. In many applications, protecting critical modules is of main concern. One such module is Fast Fourier Transform (FFT). Real FFT (RFFT) is a memory-based FFT architecture. RFFT architecture can be optimized by its processing element through employing several types of adder and multipliers and an optimized memory usage. It has been seen that various blocks operate simultaneously in many applications. For the protection of parallel FFTs using conventional Error Correction Codes (ECCs), algorithmic-based fault tolerance (ABFT) techniques like Parseval checks and its combination are seen. In this brief, the protection schemes are applied to the single RAM-based parallel RFFTs and dual RAM-based parallel RFFTs. This work is implemented on platforms such as field programmable gate arrays (FPGAs) using Verilog HDL and on application-s... [more]
Enhanced Oil Recovery and CO2 Storage Performance in Continental Shale Oil Reservoirs Using CO2 Pre-Injection Fracturing
An Zhang, Yalin Lei, Chenjun Zhang, Jiaping Tao
September 21, 2023 (v1)
Subject: Energy Policy
Keywords: carbon neutrality, CO2 pre-injection, CO2 storage, enhanced oil recovery (EOR), shale oil
CO2 pre-injection fracturing is a promising technique for the recovery of continental shale oil. It has multiple advantages, such as oil recovery enhancement, CO2 geological storage and water consumption reduction. Compared with conventional CO2 huff and puff and flooding, CO2 pre-injection features higher injection rates and pressures, leading to EOR and improved CO2 storage performance. Combining physical experiments and numerical simulation, this research systematically investigated the EOR and storage performance of CO2 pre-injection in continental shale reservoirs. The results showed that CO2 pre-injection greatly improved the oil recovery; after seven cycles of soaking, the average oil recovery factor was 39.27%, representing a relative increase of 31.6% compared with that of the conventional CO2 huff and puff. With the increasing pressure, the CO2 solubility grew in both the oil and water, and so did the CO2 adsorption in shale. Numerical simulation indicated that the average CO... [more]
Intelligent Optimization Design of Distillation Columns Using Surrogate Models Based on GA-BP
Lixiao Ye, Nan Zhang, Guanghui Li, Dungang Gu, Jiaqi Lu, Yuhang Lou
September 21, 2023 (v1)
Keywords: BP neural network, distillation column, Genetic Algorithm, intelligent design, life cycle assessment, surrogate modeling
The design of distillation columns significantly impacts the economy, energy consumption, and environment of chemical processes. However, optimizing the design of distillation columns is a very challenging problem. In order to develop an intelligent technique to obtain the best design solution, improve design efficiency, and minimize reliance on experience in the design process, a design methodology based on the GA-BP model is proposed in this paper. Firstly, a distillation column surrogate model is established using the back propagation neural network technique based on the training data from the rigorous simulation, which covers all possible changes in feed conditions, operating conditions, and design parameters. The essence of this step is to turn the distillation design process from model-driven to data-driven. Secondly, the model takes the minimum TAC as the objective function and performs the optimization search using a Genetic Algorithm to obtain the design solution with the min... [more]
Effects of Process Parameters on the Microstructure and Mechanical Properties of Large PE Pipe via Polymer Melt Jetting Stacking
Shenglin Wu, Wei Zhang, Yafeng Zhu
September 21, 2023 (v1)
Subject: Materials
Keywords: impact strength, large diameter pipe, microstructure, polymer melt jetting and stacking, tensile strength
The conventional methods for producing large-diameter pipes, such as extrusion and winding fusion welding, suffer from various drawbacks including difficulties in forming, complex molds, and high costs. Moreover, the flexibility and production efficiency of traditional manufacturing processes are relatively low. To address these challenges, this study proposes a new manufacturing process for polymer melt jetting and stacking based on fused deposition modeling (FDM) and rolling forming principles. This innovative approach aims to overcome the limitations of conventional methods and improve the flexibility and production efficiency in large-diameter pipe manufacturing. In the polymer melt jetting and stacking process, a plastic melt with a specific temperature and pressure is extruded by an extruder. The melt is then injected through the nozzle embedded in the previous layer of the pipe blank. By utilizing the localized rolling action of the forming device and adjusting the diameter usin... [more]
A Novel Power Quality Comprehensive Estimation Model Based on Multi-Factor Variance Analysis for Distribution Network with DG
Haili Ding, Pengyuan Liu, Xingzhi Chang, Bai Zhang
September 21, 2023 (v1)
Keywords: DG, multi-factor analysis of variance, power quality evaluation, significance testing
The power quality estimation for distribution network connected DG (distributed generation) is important in the power system. The significance testing for power quality indicator is less used in traditional power quality evaluation. However, the power quality indicator is affected by various factors of the power system, which seriously impact the power quality evaluation result. To solve this problem, A novel power quality comprehensive estimation model based on multi-factor variance analysis for distribution network with DG is proposed in this paper, in which the significance testing is carried out for power quality indicator with the various system factors, and then to generate the evaluation weights in different levels, further to obtain the power quality assessment results for single node. And then, the dual-significance tests are carried out to generate the weight of node and to obtain the comprehensive estimation result of whole system. At last, an example is developed to validat... [more]
Gelatin and Gelatin/Rice Starch Coatings Affect Differently Fresh-Cut Potatoes and Colocasia Slices
Anastasia Bari, Persephoni Giannouli
September 21, 2023 (v1)
Subject: Materials
Keywords: Colocasia, color, gelatin, potato, rice starch, texture
Traditional food packaging materials maintain food quality and safety during storage, but they cause significant environmental pollution. For this reason, there has been an increased demand in designing packaging materials from biodegradable ingredients such as edible proteins and polysaccharides. In the current study, biodegradable coatings from gelatin (Gel) or gelatin−rice starch (Gel-RS) mixtures were applied to fresh-cut Colocasia (Colocasia esculenta) and potato (Solanum tuberosum) samples, and main quality properties such as weight loss, firmness, breaking force, and color were evaluated during storage for seven days at 5 °C. Gel-coated potato samples kept moisture at higher levels compared to untreated samples or Gel-RS-coated samples (weight loss 41.40 ± 3.33%), while no differences in weight loss were observed for all fresh-cut Colocasia samples. Furthermore, the gelatin−rice starch coating increased the breaking force (1181.40 ± 159.73) and hardness (1609.6 ± 76.79) of fresh... [more]
Application of Landfill Gas-Water Joint Regulation Technology in Tianjin Landfill
Jun Liu, Tianqi Pan, Huihui Zhao, Yan Guo, Guanyi Chen, Li’an Hou
September 21, 2023 (v1)
Subject: Environment
Keywords: aerobic remediation, biochemical treatment, dynamic respiratory index, rapid stabilization
Landfills have long been widely used to dispose of Municipal Solid Waste (MSW). However, many landfills have faced early closure issues in recent years due to overload operations. Although in-situ aeration technology can quickly stabilize MSW, low oxygen utilization rates present a general problem that results in high energy-consuming and operating costs. This research aims to improve oxygen utilization efficiency by observing the dynamic respiratory index and the removal of contaminants. Three continuous reactors were constructed and designed with targeted aeration and re-circulation schemes for different landfill ages. The results show that a well-designed aerobic, semi-aerobic, and anaerobic reactor can fully degrade the organic components of MSW with different landfill ages, and the quantity of waste has been reduced by more than 60%. Additionally, it was disclosed that gas-water joint technology has a promotional effect on activating microorganisms.
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