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Optimal Discrete Element Parameters for Black Soil Based on Multi-Objective Total Evaluation Normalized-Response Surface Method
Zhipeng Wang, Tong Zhu, Youzhao Wang, Feng Ma, Chaoyue Zhao, Xu Li
September 21, 2023 (v1)
Keywords: black soil, discrete element methodology, multi-objective homogenization method, parameter calibration, response surface methodology, stacking angle
The lack of accurate black soil simulation model parameters in the design and optimization of soil remediation equipment has led to large errors in simulation results and simulation outcomes, which to some extent restricts the development of soil remediation equipment. Accurate discrete element parameters can improve the efficiency of soil remediation equipment. To improve the reliability of the discrete element contact parameters for black soil, a set of optimal discrete element contact parameters was found that could comprehensively represent a variety of particle sizes and minimize error. In this paper, the best discrete element contact parameters were selected by using a multi-indicator total evaluation normalization method combined with the response surface method, combined with black soil solid and simulated stacking tests. First, the physical parameters of the black soil and the accumulation angle were determined. Next, Plackett−Burman tests were carried out for each grain size... [more]
Influence of Blade Trailing-Edge Filing on the Transient Characteristics of the Centrifugal Pump during Startup
Hongchang Ding, Fei Ge, Kai Wang, Fanyun Lin
September 21, 2023 (v1)
Keywords: blade trailing-edge filing, centrifugal pump, startup, transient characteristics
During the startup process of a centrifugal pump, the vibration and noise problems caused by unsteady flow are the focus of attention, and pressure pulsation is one of the main reasons for this problem. In the current research, a special impeller with blade pressure side trimming was proposed to reduce the strong pressure pulsation phenomenon during the startup process of centrifugal pumps. This article uses numerical simulation methods to simulate three typical blade trailing edges: original trailing edge (OTE), pressure side long linear (LLPS), and pressure side short linear (SLPS), and verifies them with experimental results. The results indicate that although the head of the centrifugal pump after filing has been reduced, its efficiency has been improved to a certain extent. Thirteen monitoring points were set up near the impeller outlet circumference and volute tongue to analyze the changes in pressure pulsation, verifying that blade trimming has a significant inhibitory effect on... [more]
Impact of Formation Dip Angle and Wellbore Azimuth on Fracture Propagation for Shale Reservoir
Kefeng Yang, Lei Wang, Jingnan Ge, Jiayuan He, Ting Sun, Xinliang Wang, Yanxin Zhao
September 21, 2023 (v1)
Keywords: borehole azimuth, continental shale, formation dip angle, hydraulic fractures
The significant vertical heterogeneity, variations in ground stress directions, and irregular bedding interfaces make it extremely challenging to predict fracture propagation in continental shale reservoirs. In this article, we conducted a series of triaxial laboratory experiments on continental shale outcrop rocks to investigate the effects of formation dip angle and wellbore orientation on crack propagation under horizontal well conditions. Our study revealed that fracture propagation features can be categorized into four distinct types: (1) hydraulic fractures pass through the bedding interface without activating it; (2) fractures pass through and activate the bedding interface; (3) hydraulic fractures open and penetrate the bedding interface while also generating secondary fractures; and (4) hydraulic fractures open but do not penetrate the bedding interface. We found that as the dip angle decreases, the likelihood of fractures penetrating through the bedding interface increases. C... [more]
CFD-DEM Simulation of Fast Fluidization of Fine Particles in a Micro Riser
Guorong Wu, Qiang Li, Zhanfei Zuo
September 21, 2023 (v1)
Keywords: back-mixing, cluster, DEM, fluidized bed, heterogeneous structure, numerical simulation
In recent years, the discrete element method (DEM) has gradually been applied to the traditional fluidization simulation of fine particles in a micro fluidized bed (MFB). The application of DEM in the simulating fast fluidization of fine particles in MFB has not yet received attention. This article presents a drag model that relies on the surrounding environment of particles, namely the particle circumstance-dependent drag model or PCDD model. Fast fluidization in an MFB of fine particles is simulated using DEM based on the PCDD model. Simulations indicate that the local structure in an MFB exhibits particle aggregation, which is a natural property of fast fluidization, forming a structure where a continuous dilute phase and dispersed concentrated phase coexist. There exists a strong effect of solid back-mixing in an MFB, leading to relatively low outlet solid flux. The gas back-mixing effect is, however, not so distinct. The axial porosity shows a monotonically increasing distribution... [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]
Combining α-Al2O3 Packing Material and a ZnO Nanocatalyst in an Ozonized Bubble Column Reactor to Increase the Phenol Degradation from Wastewater
Adnan K. Majhool, Khalid A. Sukkar, May A. Alsaffar
September 21, 2023 (v1)
Subject: Materials
Keywords: multiphase reactor, ozone gas, phenol removal, reaction mechanism, removal efficiency
The ozonation reaction in a bubble column reactor (BCR) has been widely used in the removal of phenol from wastewater, but the phenol removal efficiency in this type of reactor is limited because of low ozone solubility and reactivity in the system. In the present study, the phenol degradation in the BCR was enhanced by using α-Al2O3 as a packing material and a ZnO nanocatalyst. The reactor diameter and height were 8 cm and 180 cm, respectively. The gas distributor was designed to include 52 holes of a 0.5 mm diameter. Also, the gas holdup, pressure drop, and bubble size were measured as a function of the superficial gas velocity (i.e., 0.5, 1, 1.5, 2, 2.5, and 3 cm/s). The evaluation of the hydrodynamic parameters provided a deeper understanding of the ozonation process through which to select the optimal operating parameters in the reactor. It was found that the best superficial gas velocity was 2.5 cm/s. A complete (100%) phenol removal was achieved for phenol concentrations of 15,... [more]
Study on Oil Composition Variation and Its Influencing Factors during CO2 Huff-n-Puff in Tight Oil Reservoirs
Bo Han, Hui Gao, Zhiwei Zhai, Xiaoyong Wen, Nan Zhang, Chen Wang, Zhilin Cheng, Teng Li, Deqiang Wang
September 21, 2023 (v1)
Keywords: CO2 huff-n-puff, influencing factors, numerical simulation, oil composition variation, tight oil
With immense potential to enhance oil recovery, CO2 has been extensively used in the exploitation of unconventional tight oil reservoirs. Significant variations are observed to occur in the oil’s composition as well as in its physical properties after interacting with CO2. To explore the impacts of oil properties on CO2 extraction efficiency, two different types of crude oil (light oil and heavy oil) are used in CO2 huff-n-puff experiments. Moreover, numerical simulation is implemented to quantitatively inspect the impacts of different influencing factors including production time, reservoir pressure and reservoir temperature on physical properties as well as on the oil composition variation of the crude oil. The findings of the experiments demonstrate that, whether for the light oil sample or for the heavy oil sample, hydrocarbon distribution becomes lighter after interacting with CO2 compared with the original state. In addition, it is also discovered that the hydrocarbon distributio... [more]
Triaxial Compression Strength Prediction of Fissured Rocks in Deep-Buried Coal Mines Based on an Improved Back Propagation Neural Network Model
Yiyang Wang, Bin Tang, Wenbin Tao, Anying Yuan, Tianguo Li, Zhenyu Liu, Fenglin Zhang, An Mao
September 21, 2023 (v1)
Keywords: fissured rock specimen, improved BP neural network prediction model, numerical tests, triaxial compression tests
In deep coal mine strata, characterized by high ground stress and extensive fracturing, predicting the strength of fractured rock masses is crucial for stability analysis of the surrounding rock in coal mine strata. In this study, rock samples were obtained from construction sites in deep coal mine strata and intact, as well as fissured, rock specimens were prepared and subjected to triaxial compression tests. A numerical model based on the discrete element method was then established and the micro-parameters were calibrated. A total of 288 triaxial compression tests on the rock specimens under different conditions of confining pressure, loading rate, fissure dip angle, and fissure length, were conducted to obtain the triaxial compressive strength of the fractured rock specimens under different conditions. To address the limitations of traditional back propagation (BP) neural networks in solving stochastic problems, a modified BP neural network model was developed using a random factor... [more]
Analysis of Hydrothermal Ageing on Mechanical Performances of Fibre Metal Laminates
Costanzo Bellini, Vittorio Di Cocco, Francesco Iacoviello, Larisa Patricia Mocanu, Gianluca Parodo, Luca Sorrentino, Sandro Turchetta
September 21, 2023 (v1)
Subject: Materials
Keywords: end-notched flexure test, fibre metal laminates, hydrothermal ageing
Fibre Metal Laminates (FMLs) are very interesting materials due to their light weight coupled with their high stiffness, high fatigue resistance, and high damage tolerance. However, the presence of the polymeric matrix in the composite layers and of polymeric adhesive at the metal/composite interface can constitute an Achille’s heel for this class of materials, especially when exposed to a hot environment or water. Therefore, in the present article, aluminium/carbon fibre FML specimens were produced, aged by considering different hydrothermal conditions, and then, subjected to mechanical testing. The End-Notched Flexure (ENF) test was considered for this activity. It was found that the first ageing stage, consisting of submersion in saltwater, was very detrimental to the specimens, while the second stage, composed of high and low temperature cycles, showed an increase in the maximum load, probably due to a post-curing effect of the resin during the higher temperatures of the ageing cyc... [more]
Profile Phenolic Compounds in Spanish-Style and Traditional Brine Black Olives (‘Gemlik’ Cv.) Provided from Different Regions of Türkiye
Cansu Demir, Elif Yildiz, Ozan Gurbuz
September 21, 2023 (v1)
Subject: Biosystems
Keywords: Cv. ‘Gemlik’, phenolic compounds, Spanish style, table olives, traditional processing
The aim of this study was to evaluate the effect of growing regions and processing methods on the composition and the quantity of phenolic compounds in ‘Gemlik’ variety table olives. Two different processing methods, Spanish-style and traditional brine (naturally processed) olives, were used in the processing of ‘Gemlik’ table olives. According to the data obtained in this study, the highest concentrations of phenolic compounds were observed for 3-hydroxytyrosol (4.58−168.21 mg/kg), followed by 4-hydroxyphenyl (0.76−97.58 mg/kg), luteolin 7-glucoside (0.32−58.64 mg/kg), tyrosol (1.57−47.24 mg/kg), and luteolin (0.17−53.56 mg/kg) in overall samples. The highest quantity of phenolic compounds was determined in raw olives, and the lowest phenolic compound content was determined in Spanish-style processed olives. Table olives which are produced by the natural process were observed to contain higher concentrations of phenolic compounds compared with the olives, which are produced in the Spa... [more]
Microparticles’ Lateral Oscillation Motion in Serpentine Micro-Channels without Inertial Lift Effects
Yang Liu, Xintao Hu, Jiayuan Ma, Feng Gao, Yanan Gao, Linbo Yan
September 21, 2023 (v1)
Keywords: dean drag, lateral motion, micro particles, serpentine microchannel
Micro-particle manipulation, based solely on the Dean drag force, has begun to be advocated for with the goal of lowering the pumping pressure and simplifying the complexity of the coupling effects of the inertial lift force and the Dean drag force, thus reducing the difficulty of theoretically predicting particle motion. We employed the CFD-DEM two-way coupling method in this work to quantitatively study the lateral (z in axis) motion of particles (7−10 μm), in square or half-circle segment serpentine microchannels, that was only reliant on Dean drag with the blockage ratio dDh= 0.04 (the inertial lift effects show at dDh>0.07). In the square-segment serpentine channel, under the conditions of single-side-wall sheath flow and sedimentation, we discovered that the particles exhibit a twist-type lateral trajectory around each turn, with the larger particles always twisting in the opposite direction of the smaller particles, as a result of the four-grid-pattern distribution of the latera... [more]
Effect of Inclined Orifice in Air Impingement Freezer on Heat Transfer Characteristics of Steel Strip Surface
Jing Xie, Xilan Luo, Jinfeng Wang, Yuyan Liu
September 21, 2023 (v1)
Keywords: freezer, inclination angle, jet impact, Nusselt number, uniformity of heat transfer
In order to improve the heat transfer characteristics of the air impingement freezer, an impingement freezer experimental table was designed as the research object in this paper. Numerical simulation technology was used to simulate the impingement freezer experimental table on the basis of test verification. When the other structural parameters in the impingement freezer experimental table were constant, the effect of the inclination angle of the orifice plate (θ = 60°, 65°, 70°, 75°, 80°, 85°, and 90°) on the heat transfer characteristics of a steel strip surface was analyzed by two aspects, the average Nusselt number and the heat transfer uniformity. The results showed that with the increase in the inclination angle of the orifice plate (60° ≤ θ ≤ 90°), the average Nusselt number of the steel strip surface was increased by 19.39%, and the heat transfer uniformity index was decreased by 33.69%. When θ = 90°, the average Nusselt number on steel strip was the maximum, which was 263.68,... [more]
Feature Selection of Microarray Data Using Simulated Kalman Filter with Mutation
Nurhawani Ahmad Zamri, Nor Azlina Ab. Aziz, Thangavel Bhuvaneswari, Nor Hidayati Abdul Aziz, Anith Khairunnisa Ghazali
September 21, 2023 (v1)
Subject: Biosystems
Keywords: classification, feature selection, microarray data, mutation, simulated Kalman filter
Microarrays have been proven to be beneficial for understanding the genetics of disease. They are used to assess many different types of cancers. Machine learning algorithms, like the artificial neural network (ANN), can be trained to determine whether a microarray sample is cancerous or not. The classification is performed using the features of DNA microarray data, which are composed of thousands of gene values. However, most of the gene values have been proven to be uninformative and redundant. Meanwhile, the number of the samples is significantly smaller in comparison to the number of genes. Therefore, this paper proposed the use of a simulated Kalman filter with mutation (SKF-MUT) for the feature selection of microarray data to enhance the classification accuracy of ANN. The algorithm is based on a metaheuristics optimization algorithm, inspired by the famous Kalman filter estimator. The mutation operator is proposed to enhance the performance of the original SKF in the selection o... [more]
HOMER-Based Multi-Scenario Collaborative Planning for Grid-Connected PV-Storage Microgrids with Electric Vehicles
Yifan Zhang, Shiye Yan, Wenqian Yin, Chao Wu, Jilei Ye, Yuping Wu, Lili Liu
September 21, 2023 (v1)
Keywords: collaborative planning, electric vehicles, grid-connected PV-storage microgrid, HOMER simulation, sensitivity analysis
One of the crucial methods for adapting distributed PV generation is the microgrid. However, solar resources, load characteristics, and the essential microgrid system components are all directly tied to the optimal planning scheme for microgrids. This article conducts a collaborative planning study of grid-connected PV-storage microgrids under electric vehicle integration in various scenarios using HOMER 1.8.9 software. To be more specific, in multiple scenarios, we built capacity optimization models for PV modules, energy storage, and converters in microgrids, with several scenarios each accounting for the cleanliness, economic performance, and overall performance of microgrids. For multiple scenarios, this paper used the net present value cost and levelized cost of electricity as indicators of microgrid economics, and carbon dioxide emissions and the fraction of renewable energy were used as indicators of microgrid cleanliness. The optimal capacity allocation for economy, cleanliness... [more]
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]
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