Records Added in 2023
Records added in 2023
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Showing records 1 to 25 of 36240. [First] Page: 1 2 3 4 5 Last
Thermo-Mechanical Behavior of Green Sandwich Structures for Building and Construction Applications
Forhad Hossain, Md Arifuzzaman, Md Shariful Islam, Md Mainul Islam
September 21, 2023 (v1)
Subject: Materials
Keywords: flexural properties, green sandwich structure, perlite composite-filled paper honeycomb sandwich, thermal conductivity, thermal insulation board
In this work, three different types of sandwich structures were manufactured, each using a Formica sheet (a paper-based sheet) as the skin and perlite/sodium silicate foam as the core, with or without a paper honeycomb. The sandwich structures were fabricated by attaching the Formica sheets on both sides of a paper honeycomb core panel, a perlite/sodium silicate foam core panel, and a perlite/sodium silicate foam-filled honeycomb core panel. The flexural characteristics were studied by a three-point bending test and the thermal conductivity was measured using Lee’s thermal conductivity apparatus. The results demonstrated a significant improvement in flexural properties, including core shear stress, facing stress, bending stress, and energy absorption, when incorporating the paper honeycomb reinforcement. The thermal conductivity and flexural properties of the paper honeycomb reinforced and unreinforced perlite/sodium silicate foam-based sandwich panels were found to be very compatible... [more]
Changing Law of Permeability of Coal Reservoirs under Variable Pressure Conditions and Its Influence on Extraction Efficiency of Coalbed Methane
Jianbao Liu, Zhimin Song, Chengtao Yang, Bing Li, Jiangang Ren, Shengjie Chen
September 21, 2023 (v1)
Subject: Environment
Keywords: bedding direction, extraction efficiency, gas pressure, metamorphic degree, permeability, true triaxial seepage experiment
Coal permeability data are critical in the prevention and control of coal and gas outbursts in mines and are an important reservoir parameter for the development of coalbed methane. The mechanism by which permeability is affected by gas pressure is complex. We used a self-developed true triaxial seepage experimental device that collects lignite and anthracite coal samples, sets fixed axial pressure and confining pressure, and changes gas pressure by changing the orientation of the coal seam to study the influence of the gas pressure on the permeability of the coal seam under the conditions of different coal types and different bedding orientations. Coal permeability decreased rapidly and then decreased slowly and tended to be stable with the increase in gas pressure. This conformed to the power exponential fitting relationship, and the fitting degree reached more than 99%. The comparison of the two anthracite coal samples showed that the sample’s permeability with a bedding plane verti... [more]
Comprehensive Review of Safety Studies in Process Industrial Systems: Concepts, Progress, and Main Research Topics
Jialu Zhang, Haojie Ren, Hao Ren, Yi Chai, Zhaodong Liu, Xiaojun Liang
September 21, 2023 (v1)
Keywords: process industrial systems, research review, research topics, safety, safety assessment
This paper focuses on reviewing past progress in the advancement of definitions, methods, and models for safety analysis and assessment of process industrial systems and highlighting the main research topics. Based on the analysis of the knowledge with respect to process safety, the review covers the fact that the entire system does not have the ability to produce casualties, health deterioration, and other accidents, which ultimately cause human life threats and health damage. And, according to the comparison between safety and reliability, when a system is in an unreliable state, it must be in an unsafe state. Related works show that the main organizations and regulations are developed and grouped together, and these are also outlined in the literature. The progress and current research topics of the methods and models have been summarized and discussed in the analysis and assessment of safety for process industrial systems, which mainly illustrate that the dynamic operational safety... [more]
Unlocking the Full Potential of Clove (Syzygium aromaticum) Spice: An Overview of Extraction Techniques, Bioactivity, and Future Opportunities in the Food and Beverage Industry
Ahmad Hazim Abdul Aziz, Dwila Nur Rizkiyah, Lailatul Qomariyah, Irianto Irianto, Mohd Azizi Che Yunus, Nicky Rahmana Putra
September 21, 2023 (v1)
Keywords: bioactivities, clove extraction techniques, eugenol, future opportunities, natural spices
This review article provides an overview of the bioactive compounds of clove, their health benefits, and their potential application in food and beverages. Cloves are rich in phenolic compounds, mainly eugenol, which exhibit antioxidant, anti-inflammatory, antimicrobial, antifungal, and wound-healing properties. Traditional methods of clove extraction, such as Soxhlet and maceration, have limitations. Green extraction methods, such as ultrasound-assisted extraction, pressurised liquid extraction, and microwave-assisted extraction, have shown promising results. The potential application of clove extract in various food and beverage products are also discussed. Finally, future perspectives and challenges for clove extraction are highlighted. Overall, the review highlights the potential of clove extract as a natural source of bioactive compounds for various applications in the food and beverage industry.
Optimization of Cost−Carbon Reduction−Technology Solution for Existing Office Parks Based on Genetic Algorithm
Zhenlan Dou, Lu Jin, Yinhui Chen, Zishuo Huang
September 21, 2023 (v1)
Subject: Optimization
Keywords: carbon reduction, cost benefits, existing office parks, Genetic Algorithm, retrofit, whole life cycle
With limited investment costs, how to fully utilize the carbon-reduction capacity of a campus in terms of buildings, equipment, and energy is an important issue when realizing the low-carbon retrofit of office parks. To this end, this paper establishes a mathematical optimization model for the decarbonization-based retrofit of existing office parks, based on the genetic algorithm, taking into account the relationship between cost, energy-consumption, and carbon-emissions, and taking the maximum carbon reduction of the park over its whole life as the optimization goal. The validity of the model was verified in conjunction with a case study of an office park in Nanchang, China. The case study shows that, compared with current typical parks, the carbon reduction through an office park’s decarbonization retrofit has a non-linear correlation with the investment cost, and when the total investment cost of the park is above CNY 60 million, the increase in carbon reduction with the increase in... [more]
Waste-to-Energy Pipeline through Consolidated Fermentation−Microbial Fuel Cell (MFC) System
Kundan Kumar, Ling Ding, Haiyan Zhao, Ming-Hsun Cheng
September 21, 2023 (v1)
Keywords: agriculture residues (AR), bioenergy, Fermentation, microbial fuel cell (MFC), municipal solid waste (MSW)
The rise in population, urbanization, and industrial developments have led to a substantial increase in waste generation and energy demand, posing significant challenges for waste management as well as energy conservation and production. Bioenergy conversions have been merged as advanced, sustainable, and integrated solutions for these issues, encompassing energy generation and waste upcycling of different types of organic waste. Municipal solid waste (MSW) and agricultural residues (AR) are two main resources for bioenergy conversions. Bioenergy production involves feedstock deconstruction and the conversion of platform chemicals to energy products. This review provides a detailed overview of waste sources, biofuel, and bioelectricity production from fermentation and microbial fuel cell (MFC) technology, and their economic and environmental perspectives. Fermentation plays a critical role in liquid biofuel production, while MFCs demonstrate promising potential for simultaneous product... [more]
Gout Staging Diagnosis Method Based on Deep Reinforcement Learning
Chao Ma, Changgang Pan, Zi Ye, Hanbin Ren, Hai Huang, Jiaxing Qu
September 21, 2023 (v1)
Keywords: deep reinforcement learning, disease staging diagnosis, electronic medical records, gout
In clinical practice, diseases with a prolonged course and disease characteristics at the time of diagnosis are often classified into specific stages. The precision of disease staging significantly impacts the therapeutic and curative outcomes for patients, and the diagnosis of multi-clinical-stage diseases based on electronic medical records is a problem that needs further research. Gout is a multi-stage disease. This paper focuses on the research of gout and proposes a staging diagnosis method for gout based on deep reinforcement learning. This method firstly uses the candidate binary classification model library for accurate diagnosis of gout, and then corrects the results of the binary classification through the set medical rules for diagnosis of gout, and then uses the machine learning model to diagnose different stages of corrected accurate data. In the course of the experiment, deep reinforcement learning was introduced to solve the hyperparameter tuning problem of the staging m... [more]
An Adaptive Peak Power Prediction Method for Power Lithium-Ion Batteries Considering Temperature and Aging Effects
Jilei Ye, Chao Wu, Changlong Ma, Zijie Yuan, Yilong Guo, Ruoyu Wang, Yuping Wu, Jinlei Sun, Lili Liu
September 21, 2023 (v1)
Keywords: lithium-ion battery, parameter identification, peak power prediction, state estimation
The battery power state (SOP) is the basic indicator for the Battery management system (BMS) of the battery energy storage system (BESS) to formulate control strategies. Although there have been many studies on state estimation of lithium-ion batteries (LIBs), aging and temperature variation are seldom considered in peak power prediction during the whole life of the battery. To fill this gap, this paper aims to propose an adaptive peak power prediction method for power lithium-ion batteries considering temperature and aging is proposed. First, the Thevenin equivalent circuit model is used to jointly estimate the state of charge (SOC) and SOP of the lithium-ion power battery, and the variable forgetting factor recursive least squares (VFF-RLS) algorithm and extended Kalman filter (EKF) are utilized to identify the battery parameters online. Then, multiple constraint parameters including current, voltage, and SOC were derived, considering the dependence of the polarization resistance of... [more]
Semi-Analytical Modeling of Pyrolysis Front and Ignition Temperatures of Thermally Reactive Single Solid Particles
Yousef Haseli
September 21, 2023 (v1)
Keywords: extremum temperature, ignition temperature, Modelling, pyrolysis, reaction-front temperature, thermally reactive solid
A semi-analytical approach is developed for predicting pyrolysis front temperature in a charring solid undergoing thermal decomposition. The pre-reaction heating stage is described using an analytical formulation and invoking the concept of thermal penetration depth. The solution for the solid conversion stage accounts for decomposition enthalpy, the convective flow of volatiles, and a reaction front characterized by a uniform temperature that progresses toward the inner layers. This method incorporates empirical relations into the analytical model. Two scenarios are considered. First, the solution of the pyrolysis model combined with the data of conversion time versus external heat flux leads to an algebraic expression that reveals the existence of a maximum pyrolysis-front temperature. Explicit relations are derived for both the extremum pyrolysis temperature and optimum applied heat flux. In the second case, an expression is derived for the ignition temperature of a solid fuel (e.g.... [more]
An Improved Discrete Jaya Algorithm for Shortest Path Problems in Transportation-Related Processes
Ren Wang, Mengchu Zhou, Jinglin Wang, Kaizhou Gao
September 21, 2023 (v1)
Keywords: Jaya algorithm, route planning, shortest path problem (SPP)
Shortest path problems are encountered in many engineering applications, e.g., intelligent transportation, robot path planning, and smart logistics. The environmental changes as sensed and transmitted via the Internet of Things make the shortest path change frequently, thus posing ever-increasing difficulty for traditional methods to meet the real-time requirements of many applications. Therefore, developing more efficient solutions has become particularly important. This paper presents an improved discrete Jaya algorithm (IDJaya) to solve the shortest path problem. A local search operation is applied to expand the scope of solution exploration and improve solution quality. The time complexity of IDJaya is analyzed. Experiments are carried out on seven real road networks and dense graphs in transportation-related processes. IDJaya is compared with the Dijkstra and ant colony optimization (ACO) algorithms. The results verify the superiority of the IDJaya over its peers. It can thus be w... [more]
Investigation into the Perforation Optimization in Conglomerate Reservoir Based on a Field Test
Qinghu Fan, Yonggui Ma, Junping Wang, Liang Chen, Zhiquan Ye, Yajun Xu, Huan Li, Bo Wang
September 21, 2023 (v1)
Keywords: conglomerate reservoir, field test, hydraulic fracturing, perforation scheme
The Mahu conglomerate reservoir is characterized by strong heterogeneity and the uneven stimulation of the horizontal lateral during hydraulic fracturing. The optimization of the perforation number per cluster is of great value for horizontal well multi-stage fracturing (HWMF) because the suitable perforation number not only promotes the uniform propagation of multiple fractures but also prevents excessive perforation erosion. In this work, a typical well in the Mahu conglomerate reservoir was selected, and a field test of optimizing the perforation number was carried out. The perforation schemes of three, five, and eight perforations per cluster were designed in nine fracturing stages, respectively. The wellhead pressure under different perforation schemes was compared and analyzed with the step-down flow rate test, and the optimal perforation number per cluster in the Mahu conglomerate reservoir was selected as eight. The theoretical calculation results show that eight perforations p... [more]
Thermal Treatment of Commercial Sweetener Solutions Modulates the Metabolic Responses in C57BL/6 Mice during a 24-Week-Long Exposition
Elizabeth Nieto-Mazzocco, Elena Franco-Robles, Adriana Saldaña-Robles, Neith Pacheco, César Ozuna
September 21, 2023 (v1)
Subject: Biosystems
Keywords: caloric sweeteners, non-caloric sweeteners, orexigenic and anorexigenic peptides, oxidative damage
The purpose of this paper was to evaluate the effect of thermal treatment (TT: 121 ± 2 °C, 15 min) on the composition of commercial sweeteners diluted in water (10 °Brix). Additionally, we evaluated the impact of this TT on metabolic responses in C57BL/6 mice during a 24-week treatment. The sweeteners included in this study were sucrose (SC), glucose-63 (GLU63), agave syrup (AS), sucralose (SUC), and steviol glycosides (STG). HPLC analysis showed changes in the concentration of simple sugars of GLU63 and AS after TT. Importantly, in all sweeteners, TT modulated metabolic responses in mice. The mice drinking thermally treated sweetener solution showed an increase of 10−13% (p < 0.05) in food intake (AS, SUC, and STG), beverage intake (2−21%; SC and GLU63), weight gain (38%; SUC), energy (10−13%; AS, SUC, and STG), glucose levels (11−17%; SC and STG), GLP-1 (30%; SC) and insulin (88%; AS) release, and the generation of protein carbonyl (SC) and malondialdehyde (all sweeteners tested)... [more]
Natural Convection in a Circular Enclosure with Four Cylinders under Magnetic Field: Application to Heat Exchanger
Raouia Azzouz, Mohamed Bechir Ben Hamida
September 21, 2023 (v1)
Keywords: circular enclosure, cylinders, magnetic field, natural convection, Nusselt number
This paper documents the 2D numerical study of magnetohydrodynamic unsteady natural convective heat transfer in a circular enclosure with four heating cylinders in both the horizontal and the vertical mid-plane. The fluid is an incompressible Newtonian fluid. The main transport equations based on the conservation of mass, momentum, and energy are calculated and solved using a finite element numerical solver with the following parameter ranges: dimensionless distance between cylinders S = 0.05−0.29, Rayleigh number Ra=103−106, and Hartmann number for Ha = 0−120. COMSOL Multiphysics, a numerical simulation program, was used to solve the governing equations. It was demonstrated that for lower Ra values, heat transfer through an applied magnetic field is unaffected for a specific S value because the mechanism of transport is diffusion, whereas for larger Ra, there is a complex interaction among magnetic field and physical thermal properties. The features of the heat transfer rate are deter... [more]
Nanofluids as a Waste Heat Recovery Medium: A Critical Review and Guidelines for Future Research and Use
José Pereira, Ana Moita, António Moreira
September 21, 2023 (v1)
Subject: Materials
Keywords: nanofluids, organic Rankine cycle, thermoelectric generator, waste heat conversion, waste heat recovery, waste to energy
The thermal energy storage and conversion process possesses high energy losses in the form of waste heat. The losses associated with energy conversion achieve almost 90% of the worldwide energy supply, and approximately half of these losses are waste heat. Hence, waste heat recovery approaches intend to recuperate that large amount of wasted heat from chimneys, vehicles, and solar energy systems, among others. The novel class of thermal fluids designated by nanofluids has a high potential to be employed in waste heat recovery. It has already been demonstrated that nanofluids enhance energy recovery efficiency by more than 20%. Also, the use of nanofluids can improve the energy capacity of steelworks systems by around three times. In general, nanofluids can improve efficiency and reduce exergy destruction and carbon emissions in devices like heat exchangers. The current work summarizes the application of nanofluids in waste heat recovery and discusses the involved feasibility factors. A... [more]
Analysis of the Fuel Properties of the Seed Shell of the Neem Plant (Azadirachta indica)
Francisco Simão Neto, Maria Melo Neta, Ana Sousa, Luana Damasceno, Bruna Sousa, Samuel Medeiros, Rafael Melo, Ada Lopes, José Santos, Maria Rios
September 21, 2023 (v1)
Subject: Materials
Keywords: alternative source, bioenergy, Neem, plant biomass, proximate analysis, TG, XRF
The energetic potential of the seed shell of the Neem plant (Azadirachta indica) was investigated using proximate analysis, Higher Heating Value (HHV), thermal analysis (TG-DTG and DSC) in inert and oxidative atmospheres, and X-ray fluorescence (XRF). The results of ash (3.80% ± 0.44), volatile matter (81.76% ± 1.30), fixed carbon (14.44% ± 1.74), and estimated HHV (18.791 MJ/kg: average value) are compatible with other biomasses already used as fuels in the bioenergy industry. Thermograms showed three main degradation events in synthetic air and two in nitrogen, attributed to the moisture, release of volatile materials, and decomposition of hemicellulose, cellulose, and lignin. The elements positively detected by the XRF were Ca, K, S, P, Fe, Ti, Zn, Rb, and Sr.
Optimization Study of Inert Gas Distribution for Multiple-Bay Fuel Tank
Lei Shao, Jiawei He, Xia Lu, Weihua Liu
September 21, 2023 (v1)
Subject: Optimization
Keywords: inerting system, optimization scheme, TOPSIS method, ventilation mode
Inert gas distribution has a great influence on the inerting effect, especially for the multiple-bay fuel tank. In order to find out the optimal scheme, an optimization method based on the entropy-weight improvement TOPSIS method is proposed, and an experimental system of inert gas distribution is established to measure the speed index and uniformity index. The results show that the position of the inlet and outlet has a significant effect on the overall inerting effect. The inerting scheme designed by the entropy-weight improvement TOPSIS method can not only reduce the flow demand of inert gas but also make the oxygen distribution more uniform. The optimization inerting scheme of the Boeing 747 aircraft has improved the average speed index by 3.01% and the average uniformity index by 26.18%. The smoke visualization experiment also showed that the scheme designed by the entropy-weight improvement TOPSIS method has the denser white smoke, which means that the scheme has better performan... [more]
Bearing Fault Diagnosis Based on ICEEMDAN Deep Learning Network
Bo Liang, Wuwei Feng
September 21, 2023 (v1)
Keywords: convolutional block attention module, deep learning, deep residual network, Hilbert, ICEEMDAN, rolling bearing fault diagnosis
Bearing fault diagnosis has evolved from machine learning to deep learning, addressing the issues of performance degradation in deep learning networks and the potential loss of key feature information. This paper proposes a fault diagnosis method for rolling bearing faults based on ICEEMDAN combined with the Hilbert transform (ICEEMDAN-Hilbert) and a residual network (ResNet). Firstly, the collected fault vibration signals are classified as fault samples and randomly sampled with a fixed length. The IMF components obtained by decomposing the bearing fault vibration signals using ICEEMDAN are able to maximize the restoration of fault vibrations. Then, the IMF components are transformed from one-dimensional time-domain signals to two-dimensional time-frequency domain images using Hilbert transformation. The RGB color images can be directly used in deep learning models without the need for manual labeling of a large amount of data, thereby avoiding the loss of key feature information. The... [more]
Effect of Self-Recirculating Casing Treatment on the Aerodynamic Performance of Ultra-High-Pressure-Ratio Centrifugal Compressors
Tengbo Fan, Baotong Wang, Chuanxiang Yan, Wenchao Zhang, Zhaoyun Song, Xinqian Zheng
September 21, 2023 (v1)
Keywords: aerodynamic stability, centrifugal compressor, multi-splitter blade, parametric model, self-recirculating casing treatment, ultra-high pressure ratio
The motivation to design a more efficient and compact aircraft engine leads to a continuous increase in overall pressure ratio and decrease in the stage number in compressors. Compared to the traditional multi-stage compressor, a single-stage ultra-high-pressure-ratio centrifugal compressor with a pressure ratio higher than 10.0 can significantly improve the engine’s power-to-weight ratio and fuel economy with a reduced structure complexity. Thus, it has great potential to be adopted in the compression system of advanced aero engines, such as turboshaft engines, in the future. However, the highly narrow Stable Flow Range (SFR) of ultra-high-pressure-ratio centrifugal compressors is a severe restriction for engineering applications. This research focuses on the aerodynamic performance of a ultra-high-pressure-ratio centrifugal compressor, and three-dimensional simulation is employed to investigate the effect of Self-Recirculating Casing Treatment (SRCT) on the performance and stability... [more]
Numerical Study on High Throughput and High Solid Particle Separation in Deterministic Lateral Displacement Microarrays
Maike S. Wullenweber, Jonathan Kottmeier, Ingo Kampen, Andreas Dietzel, Arno Kwade
September 21, 2023 (v1)
Keywords: Computational Fluid Dynamics, deterministic lateral displacement, discrete element method, high throughput, immersed boundary method, particle concentration, particle separation
Deterministic lateral displacement (DLD) is a high-resolution passive microfluidic separation method for separating micron-scale particles according to their size. Optimizing these microsystems for larger throughputs and particle concentrations is of interest for industrial applications. This study evaluates the limitations of the functionality of the DLD separation principle under these specific conditions. For this reason, different particle volume fractions (up to 11%) and volumetric flow rates (corresponding to Reynolds numbers up to 50) were varied within the DLD microsystem and tested in different combinations. Resolved two-way coupled computational fluid dynamics/discrete element method (CFD-DEM) simulations including spherical particles were performed. The results show a general increase in the critical diameter with increasing volume fraction and decreasing separation efficiency. The largest tested Reynolds number (Re = 50) results in the highest separation efficiency, particu... [more]
A Study on the Mechanism of Casing Deformation and Its Control Strategies in Shale Oil Hydraulic Fracturing
Nan Zhang, Peng Wang, Junliang Li, Wenhai Ma, Xiaochuan Zhang, Hongtao Zhang, Chenggang Jiang, Weiming Huang, Xinzhu Feng, Shuwei Liu
September 21, 2023 (v1)
Keywords: casing deformation, fracture slip, hydraulic fracturing, prevention of casing deformation, shale oil
The problem of casing deformation caused by large-scale hydraulic fracturing in shale oil wells severely restricts the efficient development of Gulong shale oil. In order to clarify the mechanism of casing deformation in shale oil wells, comprehensive analysis was conducted on engineering factors, multi-arm caliper logging, seismic attributes, and the distribution characteristics of casing deformations. This study shows that casing strength, cementing quality, and wellbore curvature are not the main controlling factors for casing deformation. Casing deformation is caused by the communication between hydraulic fractures and natural fractures during the fracturing process, which increases the fluid pressure in the natural fracture and induces shear slip, resulting in casing deformation due to shear stress. Based on the understanding of the mechanism of casing deformation in shale oil wells, two targeted casing deformation prevention and control methods are proposed. First, temporary plug... [more]
Evaluation of Fracture Volume and Complexity of Tight Oil Wells Based on Flowback Data
Jie Li, Sen Liu, Jianmin Li, Zhigang Liu, Xi Chen, Jiayan Li, Tianbo Liang
September 21, 2023 (v1)
Keywords: flowback analysis, hydraulic fracturing, stimulation volume, tight oil
For tight reservoirs, horizontal wells and multi-stage fracturing can generate a complex fracture network that realizes economic and effective development. The volume and complexity of the fracture network are of great significance to accurately predicting the productivity of tight oil wells. In this work, a mathematical model of a multiphase flow is proposed to evaluate the stimulation effect based on the early flowback data. The model showing the early slope of the material balance time (MBT) and production balance pressure (RNP) can help estimate the effective stimulated volume of the horizontal well. The linear flow region can be determined from the slope of the log−log plot of the MBT versus RNP curve, which equals 1. The method is verified by commercial simulation software, and the calculated stimulated volume is consistent with the statistical results of simulation results. Results also show that the flow pattern of the fracture−matrix system can be judged by the slope of the fl... [more]
Fused Data-Driven Approach for Early Warning Method of Abnormal Conditions in Chemical Process
Xiaomiao Song, Fabo Yin, Dongfeng Zhao
September 21, 2023 (v1)
Keywords: abnormal conditions, chemical process, data-driven
The utilization of data-driven methods in chemical process modeling has been extensively acknowledged due to their effectiveness. However, with the increasing complexity and variability of chemical processes, predicting and warning of anomalous conditions have become challenging. Extracting valuable features and constructing relevant warning models are critical problems that require resolution. This research proposed a novel fused method that integrates K-means density-based spatial clustering of applications with noise (DBSCAN) clustering and bi-directional long short-term memory multilayer perceptron (Bi-LSTM-MLP) to enable early warning of abnormal conditions in chemical processes. The paper applied the proposed method to analyze the early warning using actual process data from Eastman Tennessee and the atmospheric pressure reduction unit as an example. In the TE model and example, the root mean square error (RMSE) of this method is 0.006855 and 0.052546, respectively, which is quit... [more]
Advancement in Microbial Fuel Cells Technology by Using Waste Extract as an Organic Substrate to Produce Energy with Metal Removal
Ghada Mohamed Aleid, Anoud Saud Alshammari, Alamri Rahmah Dhahawi Ahmad, Fida Hussain, Sang-Eun Oh, Akil Ahmad, Mohamad Nasir Mohamad Ibrahim, Khalid Umar
September 21, 2023 (v1)
Subject: Biosystems
Keywords: Energy, heavy metals, microbial fuel cell, organic substrate, Wastewater
Energy generation using microbial fuel cells (MFC) and removing toxic metal ions is a potentially exciting new field of study as it has recently attracted a lot of interest in the scientific community. However, MFC technology is facing several challenges, including electron production and transportation. Therefore, the present work focuses on enhancing electron generation by extracting sugarcane waste. MFC was successfully operated in a batch mode for 79 days in the presence of 250 mg/L Pb2+ and Hg2+ ions. Sugarcane extract was regularly fed to it without interruption. On day 38, the maximum current density and power density were recorded, which were 86.84 mA/m2 and 3.89 mW/m2, respectively. The electrochemical data show that a sufficient voltage generation and biofilm formation produce gradually. The specific capacitance was found to be 11 × 10−4 F/g on day 79, indicating the steady growth of biofilm. On the other hand, Pb2+ and Hg2+ removal efficiencies were found to be 82% and 74.85... [more]
Study of Tangential Effusion Cooling of a Combustor Liner
Ziwan Li, Pengfu Xie, Qinghua Zeng, Xuanwu Chen
September 21, 2023 (v1)
Keywords: cooling efficiency, effusion cooling, heat and mass transfer, tangential inlet
Tangential effusion cooling of a combustor liner has a large difference from traditional effusion cooling on a plate. In this paper, numerical simulation is carried out to study the flow field, heat transfer characteristics and the factors affecting the cooling effectiveness of tangential effusion cooling of a combustor liner. It is found that the cooling film formed by the tangential jet is distributed in a divergent “horsetail” shape and adheres tightly to the inner wall of the liner, which increases the cooling area and effectiveness. Three different tangential inlet cooling hole arrangements and their cooling efficiencies are studied, and several important parameters that affect the cooling effectiveness are summarized. Then, an improved cooling hole arrangement is proposed, and its cooling efficiency is studied and compared with those of the original three arrangements. The results show that the new arrangement significantly improves the comprehensive cooling efficiency and decrea... [more]
Development of Ultrasound Piezoelectric Transducer-Based Measurement of the Piezoelectric Coefficient and Comparison with Existing Methods
Chandana Ravikumar, Vytautas Markevicius
September 21, 2023 (v1)
Keywords: acoustic method, dynamic, energy harvesting, interferometric, piezoelectric coefficient, quasi-static, ultrasound transducer
Energy harvesting using the piezoelectric material in the development of compact vibration energy harvesters can be used as a backup power source for wireless sensors or to fully replace the use of fossil-resource-wasting batteries and accumulators to power a device or sensor. Generally, the coefficient is used as the metric for evaluating the property in materials. Recent research reports that accurate measurement and calculation of the coefficient in materials, especially in polymers, can be challenging for various reasons. From the reviewed references, different methods, including the quasi-static, dynamic, interferometric, and acoustic methods, are discussed and compared based on the direct and indirect effect, accuracy, repeatability, frequency range, and so on. A development of an ultrasound piezoelectric transducer is conducted to estimate d33 coefficient with a reference value. The purpose of the method was mainly to measure the values of piezoelectric material in order to meas... [more]
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