Search results for: density flow

Authors: Khobaib Khobaib, Alexander Mikkelsen, Zbigniew Rozynek

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Electric fields have proven useful for inducing droplet deformation and to structure particles adsorbed at droplet interfaces. In this experimental research, direct current electric fields were applied to deform particle-covered droplets made out of silicone oil and immersed in castor oil. The viscosity of the drop and surrounding fluid were changed by external heating. We designed an experimental system in such a way that electric field-induced electrohydrodynamic (EHD) flows were asymmetric and only present on one side of the drop, i.e., the droplet adjoined a washer and adhered to one of the electrodes constituting the sample cell. The study investigated the influence of viscosity on the steady-state deformation magnitude of particle-laden droplets, droplet compression, and relaxation, as well as particle arrangements at drop interfaces. Initially, before the application of an electric field, we changed the viscosity of the fluids by heating the sample cell at different temperatures. The viscosity of the fluids was varied by changing the temperature of the fluids from 25 to 50°C. Under the application of a uniform electric field of strength 290 Vmm⁻¹, electric stress was induced at the drop interface, yielding drop deformation. In our study, we found that by lowering the fluid viscosity, the velocity of the EHD flows was increased, which also increases the deformation of the drop.

Keywords: drop deformation and relaxation, electric field, electrohydrodynamic flow, particle assembly, viscosity

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Authors: Yujiang Wu

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As electrical machine (e-machine) power density re-querulents become more stringent in vehicle electrification, mounting a temperature sensor for e-machine stator windings becomes increasingly difficult. This can lead to higher manufacturing costs, complicated harnesses, and reduced reliability. In this paper, we propose a deep-learning method for predicting electric machine winding temperature, which can either replace the sensor entirely or serve as a backup to the existing sensor. We compare the performance of our method, the stateful long short-term memory networks (LSTM) with truncated backpropagation through time (TBTT), with that of linear regression, as well as stateless LSTM with/without residual connection. Our results demonstrate the strength of combining stateful LSTM and TBTT in tackling nonlinear time series prediction problems with long sequence lengths. Additionally, in industrial applications, high-temperature region prediction accuracy is more important because winding temperature sensing is typically used for derating machine power when the temperature is high. To evaluate the performance of our algorithm, we developed a temperature-stratified MSE. We propose a simple but effective data preprocessing trick to improve the high-temperature region prediction accuracy. Our experimental results demonstrate the effectiveness of our proposed method in accurately predicting winding temperature, particularly in high-temperature regions, while also reducing manufacturing costs and improving reliability.

Keywords: deep learning, electrical machine, functional safety, long short-term memory networks (LSTM), thermal management, time series prediction

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Authors: Raj C. Aparna

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In India, the mandatory clause on Corporate Social Responsibility (CSR) in Companies Act, 2013 has led to varying responses from the companies. From excessive spending to resistance, the private and the public stakeholders have been considering the law from different perspectives. This paper tends to study the characteristics of CSR spending in India with emphasis on the locations to which the funds are routed. This study examines the effects of CSR fund flow on regional development by considering the growth in Gross State Domestic Product (GSDP), agriculture, education and healthcare using panel data for the 29 States in the country. The results confirm that the CSR funds have been instrumental in improving the quality of teaching and healthcare in the areas around the industrial hubs. However, the study shows that the corporates mostly invest in regions which are easily accessible to them, by their physical presence, irrespective of whether the area is developed or not. Such a skewness is visible in the extensive spending in and around the metropolitan cities, the established centers, in the country to which large chunks of CSR funds are channeled. The results show that there is a variation from what the government had proposed while initiating the CSR law to promote social inclusion and equality in the rural and isolated areas in the country. The implication is that even though societal improvement is the aim of CSR, ease of access to the needy is an essential factor in corporate choices. As poverty and lack of facilities are found in the innermost parts, it is vital to have government policies for their aid as corporate help.

Keywords: corporate social responsibility, geographic spread, panel data analysis, strategic implementation

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Authors: Masoud Ghaemi, Mohammadjafar Hedayati, Faezeh Yousefzadeh, Hoseinali Heydarzadeh

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Careful monitoring in the earth dams to measure deformation caused by settlement and movement has always been a concern for engineers in the field. In order to measure settlement and deformation of earth dams, usually, the precision instruments of settlement set and combined Inclinometer that is commonly referred to IS instrument will be used. In some dams, because the thickness of alluvium is high and there is no possibility of alluvium removal (technically and economically and in terms of performance), there is no possibility of placing the end of IS instrument (precision instruments of Inclinometer-settlement set) in the rock foundation. Inevitably, have to accept installing pipes in the weak and deformable alluvial foundation that leads to errors in the calculation of the actual settlement (absolute settlement) in different parts of the dam body. The purpose of this paper is to present new and refine criteria for predicting settlement and deformation in earth dams. The study is based on conditions in three dams with a deformation quite alluvial (Agh Chai, Narmashir and Gilan-e Gharb) to provide settlement criteria affected by the alluvial foundation. To achieve this goal, the settlement of dams was simulated by using the finite difference method with FLAC3D software, and then the modeling results were compared with the reading IS instrument. In the end, the caliber of the model and validate the results, by using regression analysis techniques and scrutinized modeling parameters with real situations and then by using MATLAB software and CURVE FITTING toolbox, new criteria for the settlement based on elasticity modulus, cohesion, friction angle, the density of earth dam and the alluvial foundation was obtained. The results of these studies show that, by using the new criteria measures, the amount of settlement and deformation for the dams with alluvial foundation can be corrected after instrument readings, and the error rate in reading IS instrument can be greatly reduced.

Keywords: earth-fill dam, foundation, settlement, finite difference, MATLAB, curve fitting

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Authors: Mao-Sheng Su, Santhanamoorthi Nachimuthu, Jyh-Chiang Jiang

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Climate change is widely recognized as a global crisis, with anthropogenic CO₂ emissions from fossil fuel combustion and industrial processes being major contributors. To address this challenge, carbon capture and sequestration (CCS) technology has emerged as a key strategy for selectively capturing CO₂ from flue gas streams. Among the various solid adsorbents, metal–organic frameworks (MOFs) are notable for their extensive surface area and controllable pore chemistry. The porous MOF structure is comprised of metal ions or clusters coordinated to organic linker compounds. In particular, the pore parameters of MOFs are readily tunable, making them promising materials for CO₂ capture applications. Among these, amine-functionalized MOFs have demonstrated exceptional CO₂ capture abilities because their high uptake capacity and selectivity. In this study, we have investigated the CO₂ capture abilities and adsorption mechanisms of the diamine-appended framework N-Ethylethylenediamine-Mg₂(4,4’-dioxidobiphenyl-3,3’-dicarboxylate) (e-2-Mg₂(dobpdc)) using density functional theory (DFT) calculations. Previous studies have suggested that CO₂ can be captured via both outer- and inner-amine binding sites. Our findings reveal that CO₂ adsorption at the outer amine site is kinetically more favorable compared to the inner amine site, with a lower energy barrier of 1.34 eV for CO₂ physisorption to chemisorption compared to the inner amine, which has an activation barrier of 1.60 eV. Furthermore, we find that CO₂ adsorption is significantly enhanced in an alkaline environment, as deprotonation of the diamine molecule reduces the energy barrier to 0.24 eV. This theoretical study provides detailed insights into CO₂ adsorption in diamine-appended e-2-Mg₂(dobpdc) MOF, offering a deeper understanding of CO₂ capture mechanisms and valuable information for the advancement of effective CO₂ sequestration technologies.

Keywords: DFT, MOFs, CO₂ capture, catalyst

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Authors: Imtiaz Ali, Krishnan Jayaraman, Debes Bhattacharyya

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Soybean concentrate is abundant material and renewable product that is recently been explored as an alternative to conventional formaldehyde based resins in wood based products. The main goal of this study is to evaluate the technical feasibility of manufacturing environment friendly MDF panels from renewable resources. The panels are made by using kenaf bast fibers (KB) as wood substitute and soy based adhesive as bonding material. Second order response surface regression models are used to understand the effects and interactions of resin content (RC) and pressing time (PT) on the mechanical and water soaking properties of kenaf panels. The mechanical and water soaking properties are significantly improved as the RC increased and reached at the highest level at maximum resin loading (12%). The effect of pressing time is significant in the first phase when the pressing time increased from 4 to 6 min; however the effect was not as significant when pressing time further increased to 8 min. The second order regression equations further confirm that the variation in process parameters has strong relationship with the physciomechanical properties. The MDF panels the minimum requirements of internal bond strength, modulus of rupture and modulus of elasticity as recommended by US wood MDF standard specifications for G110, G120, G130 and G140 grade MDF panels. However, the thickness swelling results are considerably poorer than the recommended values of general purpose standard requirements. This deficiency can be counterbalanced by the advantage of being formaldehyde free panels made from renewable sources and by making them suitable alternative for less humid environment applications.

Keywords: kenaf, Medium density fibreboard, soy adhesive, mechanical properties, water soaking properties

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Authors: Ezequiel Garcia-Rodriguez, Lenin Hernandez-Ferreyra, Luis Ochoa-Franco

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The Sustainable Sewer Urban Systems (SSUS) are mechanisms integrated into the cities for manage rain water, reducing its runoff volume and velocity, enhancing the rain water quality and preventing flooding and other catastrophes associated to the rain, as well as improving the energy efficiency. The objective of SSUS is to mimic or to equal the runoff and infiltration natural conditions of the land before its urbanization, reducing runoff that may cause troubles within the houses, as well as flooding. At the same time, energy for warming homes and for pumping and treating water is reduced, contributing to the reduction of CO₂ emissions and therefore contributing to reduce the climate change. This paper contains an evaluation of the advantages that SSUS may offer within a zone of Morelia City, Mexico, applying support tools for decision making. The hydrological conditions prior to and after the urbanization of the study area were analyzed to propose the recommended SSUS. Different types of SSUS were proposed in this case study, assessing their effect on the rainwater flow behavior within the study area. SSUS usage in this case resulted, positively, in an important reduction of the magnitude and velocity of runoff, reducing therefore the risk of flooding. So that, it is recommended the implementation of SSUS in this case.

Keywords: energy efficiency, morelia, sustainablesewer, urban systems

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Authors: Emad Heydarnia, Aref Sepasi, Nika Asefi, Sara Khakshournia, Javad Mohammadnejad

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Background: Despite breakthrough therapeutics in breast cancer, it is one of the main causes of mortality among women worldwide. Thus, drug therapies for treating breast cancer have recently been developed by scientists. Metformin and Sorafenib are well-known therapeutic in breast cancer. In the present study, we combined Sorafenib and PCL-sorafenib with metformin to improve drug absorption and promote therapeutic efficiency. Methods: The MCF-7 cells were treated with Metformin, Sorafenib, or PCL-sorafenib. The growth inhibitory effect of these drugs and cell viability were assessed using MTT and flow cytometry assays, respectively. The expression of targeted genes involved in cell proliferation, signaling, and the cell cycle was measured by Real-time PCR. Results: The results showed that MCF-7 cells treated with Metformin/Sorafenib and PCL-sorafenib/Metformin co-treatment contributed to 50% viability compared to untreated group. Moreover, PI and Annexin V staining tests showed that the cells viability for Metformin/Sorafenib and PCL-sorafenib/Metformin was 38% and 17%, respectively. Furthermore, Sorafenib/Metformin and PCL-sorafenib/Metformin leads to p53 gene expression increase by which they can increase ROS, thereby decreasing GPX4 gene expression. In addition, they affected the expression of BCL2, and BAX genes and altered the cell cycle. Conclusion: Together, the combination of PCL-sorafenib/Metformin and Sorafenib/Metformin increased Sorafenib absorption at lower doses and also leads to apoptosis and oxidative stress increases in MCF-7 cells.

Keywords: breast cancer, metformin, nanotechnology, sorafenib

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Authors: Maniyarasan Rajendran

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Every design has a process, and every architect deals in the ways best known to them. The design translation from the concept to completion change in accordance with their design philosophies, their tools, availability of resources, and at times the clients and the context of the design as well. The approach to understanding the design process requires formalisation of the design intents. The design process is characterised by change, with the time and the technology. The design flow is just indicative and never exhaustive. The knowledge and experience of stakeholders remain limited to the part they played in the project, and their ability to remember, and is through the Photographs. These artefacts, when circulated can hardly tell what the project is. They can never tell the narrative behind. In due course, the design processes are lost. The Design junctions are lost in the journey. Photographs acted as major source materials, along with its importance in architectural revivalism in the 19th century. From the history, we understand that it has been photographs, that act as the dominant source of evidence. The idea of recording is also followed with the idea of getting inspired from the records and documents. The design concept, the architectural firms’ philosophies, the materials used, the special needs, the numerous ‘Trial-and-error’ methods, design methodology, experience of failures and success levels, and the knowledge acquired, etc., and the various other aspects and methods go through in every project, and they deserve/ought to be recorded. The knowledge can be preserved and passed through generations, by documenting the design processes involved. This paper explores the idea of a process documentation as a tool of self-reflection, creation of architectural firm’ repository, and these implications proceed with the design evolution of the team.

Keywords: architecture, design, documentation, records

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Authors: Faizan Ali, Dayu Zhou, Xiaohua Liu, Tony Schenk, Johannes Muller, Uwe Schroeder

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Recently, the ferroelectricity (FE) and anti-ferroelectricity (AFE) introduced in so-called 'high-k dielectric' HfO₂ material incorporated with various dopants (Si, Gd, Y, Sr, Gd, Al, and La, etc.), HfO₂-ZrO₂ solid-solution, Al or Si-doped Hf₀.₅Zr₀.₅O₂ and even undoped HfO₂ thin films. The origin of FE property was attributed to the formation of a non-centrosymmetric orthorhombic (o) phase of space group Pbc2₁. To the author’s best knowledge, AFE property was observed only in HfO₂ doped with a certain amount of Si, Al, HfₓZr₁₋ₓO₂ (0 ≤ x < 0.5), and in Si or Al-doped Hf₀.₅Zr₀.₅O₂. The origin of the anti-ferroelectric behavior is an electric field induced phase transition between the non-polar tetragonal (t) and the polar ferroelectric orthorhombic (o) phase. Compared with the significant amount of studies for the FE properties in the context of non-volatile memories, AFE properties of HfO₂-based and HfₓZr₁₋ₓO₂ (HZO) thin films have just received attention recently for energy-related applications such as electrocaloric cooling, pyroelectric energy harvesting, and electrostatic energy storage. In this work, energy storage and solid state cooling properties of Si-doped HfO₂ AFE thin films are investigated. Owing to the high field-induced polarization and slim double hysteresis, an extremely large Energy storage density (ESD) value of 61.2 J cm⁻³ is achieved at 4.5 MV cm⁻¹ with high efficiency of ~65%. In addition, the ESD and efficiency exhibit robust thermal stability in 210-400 K temperature range and excellent endurance up to 10⁹ times of charge/discharge cycling at a very high electric field of 4.0 MV cm⁻¹. Similarly, for solid-state cooling, the maximum adiabatic temperature change (

Keywords: thin films, energy storage, endurance, solid state cooling, anti-ferroelectric

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Authors: Syed Muhammad Basit Ali, Usama Saleem, Irtiza Ali

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Internal combustion engines have been pioneers in the aviation industry, use of piston engines for aircraft propulsion, from propeller-driven bi-planes to turbo-prop, commercial, and cargo airliners. To provide an adequate amount of thrust piston engine rotates the propeller at a specific rpm, allowing enough mass airflow. Thrust is the only forward-acting force of an aircraft that helps heavier than air bodies to fly, depending on the mathematical model and variables included in that with the correct measurement. Test-benches have been a bench-mark in the aerospace industry to analyse the results before a flight, having paramount significance in reliability and safety engineering, depending on the mathematical model and variables included in that with the correct measurement. Calculation of thrust from a piston engine also depends on environmental changes, the diameter of the propeller, and the density of air. The project would be centered on piston engines used in the aviation industry for light aircraft and UAVs. A static thrust test bench involves various units, each performing a designed purpose to monitor and display. Static thrust tests are performed on the ground, and safety concerns hold paramount importance. The execution of this study involves research, design, manufacturing, and results based on reverse engineering initiating from virtual design, analytical analysis, and simulations. The final evaluation of results gathered from various methods such as co-relation between conventional mass-spring and digital loadcell. On average, we received 17.5kg of thrust (25+ engine run-ups – around 40 hours of engine run), only 10% deviation from analytically calculated thrust –providing 90% accuracy.

Keywords: aviation, aeronautics, static thrust, test bench, aircraft maintenance

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Authors: Joao Paulo Matheus, Renan Fangel

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Rheumatoid arthritis is a chronic, inflammatory, systemic and progressive disease that affects the synovial joints bilaterally, causing definitive orthopedic damage. It has a higher prevalence in postmenopausal female patients. It is a disabling disease that causes joint deformities that may compromise the functionality of the affected segment. The aim of this study was to evaluate the influence of low-intensity therapeutic laser on the perception of pain and quality of life in patients with rheumatoid arthritis. This is a randomized clinical study involving 6 women with a mean age of 56.8+6.3 years. Exclusion criteria: patients with acute pain, chronic infectious disease, underlying acute or chronic underlying disease. An AsGaAl laser with 808nm wavelength, 100mW power, beam output area of 0.028cm2, power density of 3.57W/cm2 was used. The laser was applied at pre-defined points in the interphalangeal and metacarpophalangeal joints, totaling 24 points, 2 times a week, for 4 weeks, totaling 8 sessions. The Pain Inventory (IBD) and Visual Analogue Scale (VAS) were used for the analysis of pain and for the WHOQOL-bref quality of life assessment. There was no statistical difference between the onset (5.67±2.66) and the final (4.67±3.78) of treatments (p=0.70). There was also no statistical difference between the beginning (5.67±2.66) and the final (4.67±3.78) of the treatments in the VAS analysis (p=0.68). The overall mean quality of life obtained by the questionnaire at the start of treatment was 42.3±7.6, while at the end of treatment it was 58.5±7.6 (p=0.01) and the domains of the questionnaire with significant differences were: psychological domain 42.9±6.8 and 66.7±12.9 (p=0.004), social domain 39.9±5.7 and 68.1±6.3 (p=0,0005) and environmental domain 36.3±7.3 and 56.3±12.5 (p=0.003). It can be concluded that the low-intensity therapeutic laser did not produce significant changes in the painful period of rheumatoid arthritis patients. However, there was an improvement in patients' quality of life in the psychological, social and environmental aspects.

Keywords: laser therapy, pain, quality of life, rheumatoid arthritis

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Authors: Suarez-Puello Alejandro, Baquero-Ruiz Andrés F, Suarez-Puello Rodrigo

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This paper discusses the results of a foresight exercise which analyzes Bogota’s fruit, vegetable and tuber supply chain strategy- described at the Food Supply and Security Master Plan (FSSMP)-to provide the inhabitants of Bogotá, Colombia, with basic food products at a fair price. The methodology consisted of using quantitative and qualitative foresight tools such as system dynamics and variable selection methods to better represent interactions among stakeholders and obtain more integral results that could shed light on this complex situation. At first, the Master Plan is an input to establish the objectives and scope of the exercise. Then, stakeholders and their relationships are identified. Later, system dynamics is used to model product, information and money flow along the fruit, vegetable and tuber supply chain. Two scenarios are presented, discussing actions by the public sector and the reactions that could be expected from the whole food supply system. Finally, these impacts are compared to the Food Supply and Security Master Plan’s objectives suggesting recommendations that could improve its execution. This foresight exercise performed at a governmental level is intended to promote the widen the use of foresight as an anticipatory, decision-making tool that offers solutions to complex problems.

Keywords: decision making, foresight, public policies, supply chain, system dynamics

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Authors: Saleh B. Mohamed, Mohamed H. Elhsnawi, Mesbah M. Salem

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Current and future applications of small gas turbine engines annular type combustors have requirements presenting difficult disputes to the combustor designer. Reduced cost and fuel consumption and improved durability and reliability as well as higher temperatures and pressures for such application are forecast. Coupled with these performance requirements, irrespective of the engine size, is the demand to control the pollutant emissions, namely the oxides of nitrogen, carbon monoxide, smoke and unburned hydrocarbons. These technical and environmental challenges have made the design of small size combustion system a very hard task. Thus, the main target of this work is to generalize a calculation method of annular type combustors for small gas turbine engines that enables to understand the fundamental concepts of the coupled processes and to identify the proper procedure that formulates and solves the problems in combustion fields in as much simplified and accurate manner as possible. The combustion chamber in task is designed with central vaporizing unit and to deliver 516.3 KW of power. The geometrical constraints are 142 mm & 140 mm overall length and casing diameter, respectively, while the airflow rate is 0.8 kg/sec and the fuel flow rate is 0.012 kg/sec. The relevant design equations are programmed by using MathCAD language for ease and speed up of the calculation process.

Keywords: design of gas turbine, small engine design, annular type combustors, mechanical engineering

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Authors: M. Hisham, S. Cabemaiwai, S. Prasad, T. Dauvakatini, R. Ananthanarayanan

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A solenoid valve is an important part of many fluid systems. Its purpose is to regulate fluid flow in a machine. Due to the crucial role of the solenoid valve and its design intricacy, it is quite expensive to obtain in Fiji and is not manufactured locally. A concern raised by the local health industry is that the housing of the solenoid valve gets damaged when machines are continuously being used and this part of the valve is very costly to replace due to the lack of availability in Fiji and many other South Pacific region countries. This study explores the agile manufacturing of a solenoid coil housing using the Fused Deposition Modeling (FDM) process. An emergy study was carried out to analyze the feasibility and sustainability of producing the part locally after estimating a Unit Emergy Value (or emergy transformity) of 1.27E+05 sej/j for the electricity in Fiji. The total emergy of the process was calculated to be 3.05E+12 sej, of which a majority was sourced from imported services and materials. Renewable emergy sources contributed to just 16.04% of the total emergy. Therefore, the part is suitable to be manufactured in Fiji with a reasonable quality and a cost of $FJ 2.85. However, the loading on the local environment is found to be significant and therefore, alternative raw materials for the filament like recycled PET should be explored or alternative manufacturing processes may be analyzed before committing to fabricating the part using FDM in its analyzed state.

Keywords: emergy analysis, fused deposition modeling, solenoid valve housing, sustainable production

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Authors: J. Thirunavukkarasu, M. Poulet, T. Turner, S. Pickering

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Composite waste from manufacturing can consist of different fiber materials, including blends of different fiber. Commercially, the recycling of composite waste is currently limited to carbon fiber waste and recycling glass fiber waste is currently not economically viable due to the low cost of virgin glass fiber and the reduced mechanical properties of the recovered fibers. For this reason, the recycling of hybrid fiber materials, where carbon fiber is combined with a proportion of glass fiber, cannot be processed economically. Therefore, a separation method is required to remove the glass fiber materials during the recycling process. An electrostatic separation method is chosen for this work because of the significant difference between carbon and glass fiber electrical properties. In this study, an experimental rig has been developed to measure the electrostatic charge achievable as the materials are passed through a tube. A range of particle lengths (80-100 µm, 6 mm and 12 mm), surface state conditions (0%SA, 2%SA and 6%SA), and several tube wall materials have been studied. A polytetrafluoroethylene (PTFE) tube and recycled without sizing agent was identified as the most suitable parameters for the electrical separation method. It was also found that shorter fiber lengths helped to encourage particle flow and attain higher charge values. These findings can be used to develop a separation process to enable the cost-effective recycling of hybrid fiber composite waste.

Keywords: electrostatic charging, hybrid fiber composites, recycling, short fiber composites

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Authors: Hamed Sadeghi, Pouya A. Panahi, Hamed Nasiri, Mohammad Sadeghi

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Collapsible soils like loess comprise an important category of problematic soils for construction purposes and sustainable development. As a result, research on both geological and geotechnical aspects of this type of soil have been in progress for decades. However, considerable natural variability in physical properties of in-situ loess strata even in a single block sample challenges the fundamental laboratory investigations. The reason behind this is that it is somehow impossible to remove the effect of a specific factor like void ratio from fair comparisons to come with a reliable conclusion. In order to cope with this limitation, two types of artificially made dispersive and calcareous loess are introduced which can be easily reproduced in any soil mechanics laboratory provided that all its compositions are known and controlled. The collapse potential is explored for a variety of soil water salinity and lime content and comparisons are made against the natural soil behavior. Trends are reported for the influence of pore water salinity on collapse potential under different osmotic flow conditions. The most important advantage of artificial loess is the ease of controlling cementing agent content like calcite or dispersive potential for studying their influence on mechanical soil behavior.

Keywords: artificial loess, unsaturated soils, collapse potential, dispersive clays, laboratory tests

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Authors: Nirupama Sam

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COVID-19, the greatest pandemic since the turn of the century, presents several issues for urban planners, the most significant of which is determining appropriate mitigation techniques for creating pandemic-friendly and resilient public spaces. The study is conducted in four stages. The first stage consisted of literature reviews to examine the evolution and transformation of public spaces during pandemics throughout history and the role of public spaces during pandemic outbreaks. The second stage is to determine the factors that influence the success of public spaces, which was accomplished by an analysis of current literature and case studies. The influencing factors are categorized under comfort and images, uses and activity, access and linkages, and sociability. The third stage is to establish the priority of identified factors for which a questionnaire survey of stakeholders is conducted and analyzing of certain factors with the help of GIS tools. COVID-19 has been in effect in India for the last two years. Kerala has the highest daily COVID-19 prevalence due to its high population density, making it more susceptible to viral outbreaks. Despite all preventive measures taken against COVID-19, Kerala remains the worst-affected state in the country. Finally, two live case studies of the hardest-hit localities, namely Subhash bose park and Napier Museum park in the Ernakulam and Trivandrum districts of Kerala, respectively, were chosen as study areas for the survey. The responses to the questionnaire were analyzed using SPSS for determining the weights of the influencing factors. The spatial success of the selected case studies was examined using the GIS interpolation model. Following the overall assessment, the fourth stage is to develop strategies and guidelines for planning public spaces to make them more efficient and robust, which further leads to improved quality, safety and resilience to future pandemics.

Keywords: urban design, public space, covid-19, post-pandemic, public spaces

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Authors: Hongquan Zhang

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Inspired by endogenous protein motors, researchers have constructed various synthetic DNA motors based on the specificity and predictability of Watson-Crick base pairing. However, the application of DNA motors to signal amplification and biosensing is limited because of low mobility and difficulty in real-time monitoring of the walking process. The objective of our work was to construct a new type of DNA motor termed target-triggered DNA motors that can walk for hundreds of steps in response to a single target binding event. To improve the mobility and processivity of DNA motors, we used gold nanoparticles (AuNPs) as scaffolds to build high-density, three-dimensional tracks. Hundreds of track strands are conjugated to a single AuNP. To enable DNA motors to respond to specific protein and nucleic acid targets, we adapted the binding-induced DNA assembly into the design of the target-triggered DNA motors. In response to the binding of specific target molecules, DNA motors are activated to autonomously walk along AuNP, which is powered by a nicking endonuclease or DNAzyme-catalyzed cleavage of track strands. Each moving step restores the fluorescence of a dye molecule, enabling monitoring of the operation of DNA motors in real time. The motors can translate a single binding event into the generation of hundreds of oligonucleotides from a single nanoparticle. The motors have been applied to amplify the detection of proteins and nucleic acids in test tubes and live cells. The motors were able to detect low pM concentrations of specific protein and nucleic acid targets in homogeneous solutions without the need for separation. Target-triggered DNA motors are significant for broadening applications of DNA motors to molecular sensing, cell imagining, molecular interaction monitoring, and controlled delivery and release of therapeutics.

Keywords: biosensing, DNA motors, gold nanoparticles, signal amplification

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Authors: Khalid Kaddoura, Ahmed Assad, Tarek Zayed

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Sewer pipelines are prone to deterioration over-time. In fact, their deterioration does not follow a fixed downward pattern. This is in fact due to the defects that propagate through their service life. Sewer pipeline defects are categorized into distinct groups. However, the main two groups are the structural and operational defects. By definition, the structural defects influence the structural integrity of the sewer pipelines such as deformation, cracks, fractures, holes, etc. However, the operational defects are the ones that affect the flow of the sewer medium in the pipelines such as: roots, debris, attached deposits, infiltration, etc. Yet, the process for each defect to emerge follows a cause and effect relationship. Deformation, which is the change of the sewer pipeline geometry, is one type of an influencing defect that could be found in many sewer pipelines due to many surrounding factors. This defect could lead to collapse if the percentage exceeds 15%. Therefore, it is essential to predict the deformation percentage before confronting such a situation. Accordingly, this study will predict the percentage of the deformation defect in sewer pipelines adopting the multiple regression analysis. Several factors will be considered in establishing the model, which are expected to influence the defamation defect severity. Besides, this study will construct a time-based curve to understand how the defect would evolve overtime. Thus, this study is expected to be an asset for decision-makers as it will provide informative conclusions about the deformation defect severity. As a result, inspections will be minimized and so the budgets.

Keywords: deformation, prediction, regression analysis, sewer pipelines

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Authors: Changyong Liu, Junda Tong, Feng Xu, Ninggui Huang

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In the injection molding process, the performance of cooling channels is crucial to the part quality. Through the application of conformal cooling channels fabricated via metal additive manufacturing, part distortion, warpage can be greatly reduced and cycle time can be greatly shortened. However, the properties of additively manufactured conformal cooling channels are quite different from conventional drilling processes such as the poorer dimensional accuracy and larger surface roughness. These features have significant influences on its cooling performance. In this study, test molds with the cooling channel diameters of φ2 mm, φ3 mm and φ4 mm were fabricated via selective laser melting and conventional drilling process respectively. A test system was designed and manufactured to measure the pressure difference between the channel inlet and outlet, the coolant flow rate and the temperature variation during the heating process. It was found that the cooling performance of SLM-fabricated channels was poorer than drilled cooling channels due to the smaller sectional area of cooling channels resulted from the low dimensional accuracy and the unmolten particles adhered to the channel surface. Theoretical models were established to determine the friction factor and heat transfer coefficient of SLM-fabricated cooling channels. These findings may provide guidance to the design of conformal cooling channels.

Keywords: conformal cooling channels, selective laser melting, cooling performance, injection molding

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Authors: Yoel Agustheo Rinding

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Globalization has made physical borders between countries become more obscure. Due to the free flow of information between countries, issue for instance, environment has become global concern. The concern has grown as the result of endless campaign made by most of the non-governmental organizations (NGOs). By means of this situation, international voluntary initiatives on environmental issues have appeared to be popular among world’s society today especially for youth. AIESEC as international non-governmental organization (INGO) through IGreen Project has initiated environmental international voluntary initiatives concerning in environmental awareness of Bandung’s citizen. Bandung itself is still struggling on solving flood as one of its major problems regardless the fact that Bandung is one of the most developed cities in Indonesia. This paper would like to discuss on how globalization affects AIESEC as an INGO in order to spread its influence and also on how it could build international voluntary initiatives networks. Afterwards, author would like to elaborate how both AIESEC and youth perceive the importance of international voluntary initiatives by using cosmopolitanism approach. In order to get a deep understanding of how this activity works, this paper also would like to explain regarding the management, expected outcomes, and the real impacts of IGreen project towards Bandung. In the end of this paper, author would like to propose solutions on how to utilize international voluntary initiatives as a solution for environmental issues nowadays.

Keywords: AIESEC, cosmopolitanism, environmental issues, globalization, IGreen project, international environmental voluntary initiatives, INGO, youth

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Authors: Hai Nguyen Tien

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On the basis of the structure of alluvial sediments explained by echo sounding data and remote sensing images, the following results can be given: The estuary of Lam river (from Ben Thuy bridge to Cua Hoi) is divided into 3 channel (location is calculated according to the river bank on the Nghe An province) : i) channel I (from Ben Thuy bridge to Hung Hoa) is the branching river; ii) channel II (from Hung Hoa to Nghi Thai is a channel develops in a meandering direction with a concave side toward Ha Tinh province; iii) channel III, from Nghi Thai to Cua Hoi is a channel develops in a meandering direction with a concave side toward Nghe An province. This estuary area is formed in the period from after the sea level dropped below 0m (current water level) to the present: i) Chanel II developed moving towards Ha Tinh provnce; ii) Chanel III developed moving towards Nghe An province; iii) In chanel I, a second river branch is formed because the flow of river cuts through the Hong Lam- Hong Nhat mudflat, at the same time creating an island. Morphological characteristics of the estuary area of Lam River are the main result of erosion and deposition activities corresponding to two water levels: low water level below 0 m and water level 0 m (current water level). Characteristics of the sediment layers on the riverbed in the estuary can be used to determine the sea levels in Late Holocene–Present.

Keywords: Lam River, development, Cua Hoi, river morphology

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Authors: Amokrane Boufares, Elise Provost, Veronique Osswald, Pascal Clain, Anthony Delahaye, Laurence Fournaison, Didier Dalmazzone

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Gas hydrates have long been considered as problematic for flow assurance in natural gas and oil transportation. On the other hand, they are now seen as future promising materials for various applications (i.e. desalination of seawater, natural gas and hydrogen storage, gas sequestration, gas combustion separation and cold storage and transport). Nonetheless, a better understanding of the crystallization mechanism of gas hydrate and of their formation kinetics is still needed for a better comprehension and control of the process. To that purpose, measuring the real-time evolution of the dissolved gas concentration in the aqueous phase during hydrate formation is required. In this work, CO₂ hydrates were formed in a stirred reactor equipped with an Attenuated Total Reflection (ATR) probe coupled to a Fourier Transform InfraRed (FTIR) spectroscopy analyzer. A method was first developed to continuously measure in-situ the CO₂ concentration in the liquid phase during solubilization, supersaturation, hydrate crystallization and dissociation steps. Thereafter, the measured concentration data were compared with those of equilibrium concentrations. It was observed that the equilibrium is instantly reached in the liquid phase due to the fast consumption of dissolved gas by the hydrate crystallization. Consequently, it was shown that hydrate crystallization kinetics is limited by the gas transfer at the gas-liquid interface. Finally, we noticed that the liquid-hydrate equilibrium during the hydrate crystallization is governed by the temperature of the experiment under the tested conditions.

Keywords: gas hydrate, dissolved gas, crystallization, infrared spectroscopy

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Authors: Chinmay Shah

Abstract:

The project is all about development of a close loop traffic light control system using PLC (Programmable Logic Controller). This project is divided into two parts which are hardware and software. The hardware part for this project is a model of four way junction of a traffic light. Three indicator lamps (Red, Yellow and Green) are installed at each lane for represents as traffic light signal. This traffic control model is a replica of actuated traffic control. Actuated traffic control system is a close loop traffic control system which controls the timing of the indicator lamps depending on the fluidity of traffic for a particular lane. To make it autonomous, in each lane three IR sensors are placed which helps to sense the percentage of traffic present on any particular lane. The IR Sensors and Indicator lamps are connected to LG PLC XGB series. The PLC controls every signal which is coming from the inputs (IR Sensors) to software and display to the outputs (Indicator lamps). Default timing for the indicator lamps is 30 seconds for each lane. But depending on the percentage of traffic present, if the traffic is nearly 30-35%, green lamp will be on for 10 seconds, for 65-70% traffic it will be 20 seconds, for full 100% traffic it will be on for full 30 seconds. The software part that operates with LG PLC is “XG 5000” Programmer. Using this software, the ladder logic diagram is programmed to control the traffic light base on the flow chart. At the end of this project, the traffic light system is actuated successfully by PLC.

Keywords: close loop, IR sensor, PLC, light control system

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Authors: Imtisal-e-Noor, Andrew Martin, Olli Dahl

Abstract:

Chemical Mechanical Polishing (CMP) has developed as a chosen planarization technique in nano-electronics industries for fabrication of the integrated circuits (ICs). These CMP processes release a huge amount of wastewater that contains oxides of nano-particles (silica, alumina, and ceria) and oxalic acid. Since, this wastewater has high solid content (TS), chemical oxygen demand (COD), and turbidity (NTU); therefore, in order to fulfill the environmental regulations, it needs to be treated up to the local and international standards. The present study proposed a unique CMP wastewater treatment method called Membrane Distillation (MD). MD is a non-isothermal membrane separation process, which allows only volatiles, i.e., water vapors to permeate through the membrane and provides 100% contaminants rejection. The performance of the MD technology is analyzed in terms of total organic carbon (TOC), turbidity, TS, COD, and residual oxide concentration in permeate/distilled water while considering different operating conditions (temperature, flow rate, and time). The results present that high-quality permeate has been recovered after removing 99% of the oxide particles and oxalic acid. The distilled water depicts turbidity < 1 NTU, TOC < 3 mg/L, TS < 50 mg/L, and COD < 100 mg/L. These findings clearly show that the MD treated water can be reused further in industrial processes or allowable to discharge in any water body under the stringent environmental regulations.

Keywords: chemical mechanical polishing, environmental regulations, membrane distillation, wastewater treatment

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Authors: Sharmin Ferdewsi Rakhi, A. H. M. Mohsinul Reza, Brynley Davies, Jianzhong Wang, Youhong Tang, Jian Qin

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Mass production of microalgae has become a focus of research owing to their promising aspects for sustainable food, biofunctional compounds, and biofuel feedstock. However, low lipid content with optimum algal biomass is still a challenge that must be resolved for commercial use. This research aims to determine the effects of light spectral shift and reactive oxygen species (ROS) on growth and lipid biosynthesis in a green microalga, Chlamydomonas reinhardtii. Aggregation Induced Emission (AIE)-based photosensitisers, CN-TPAQ-PF6 ([C₃₂H₂₃N₄]+) with high ROS productivity, was introduced into the algal culture media separately for effective conversion of the green-yellow-light to the red spectra. The intense photon energy and high-photon flux density in the photosystems and ROS supplementation induced photosynthesis and lipid biogenesis. In comparison to the control, maximum algal growth (0.15 g/l) was achieved at 2 µM CN-TPAQ-PF6 exposure. A significant increase in total lipid accumulation (146.87 mg/g dry biomass) with high proportion of 10-Heptadecanoic acid (C17:1) linolenic acid (C18:2), α-linolenic acid (C18:3) was observed. The elevated level of cellular NADP/NADPH triggered the Acetyl-Co-A production in lipid biogenesis cascade. Furthermore, MTT analysis suggested that this nanomaterial is highly biocompatible on HaCat cell lines with 100% cell viability. This study reveals that the AIE-based approach can strongly impact algal biofactory development for sustainable food, healthy lipids and eco-friendly biofuel.

Keywords: microalgae, photosensitiser, lipid, biomass, aggregation-induced-emission, reactive oxygen species

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Authors: Shuo Tian, Xuepiao Bai, Jianqin Shang, Pengtao Gai, Yuansong Zeng

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Shot peen forming is an essential forming process for aircraft metal wing panel. With the development of computer simulation technology, scholars have proposed a numerical simulation method of shot peen forming based on stress field. Three shot peen forming indexes of crater diameter, shot speed and surface coverage are required as simulation parameters in the stress field method. It is necessary to establish the relationship between simulation and experimental process parameters in order to simulate the deformation under different shot peen forming parameters. The shot peen forming tests of the 2024-T351 aluminum alloy workpieces were carried out using uniform test design method, and three factors of air pressure, feed rate and shot flow were selected. The second-order response surface model between simulation parameters and uniform test factors was established by stepwise regression method using MATLAB software according to the results. The response surface model was combined with the stress field method to simulate the shot peen forming deformation of the workpiece. Compared with the experimental results, the simulated values were smaller than the corresponding test values, the maximum and average errors were 14.8% and 9%, respectively.

Keywords: shot peen forming, process parameter, response surface model, numerical simulation

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Authors: Mahdi Akbari, Ali Torabi Haghighi

Abstract:

Hamun Lakes, located in the Helmand Basin, consisting of four water bodies, were the greatest (>8500 km2) freshwater bodies in Iran plateau but have almost entirely desiccated over the last 20 years. The desiccation of the lakes caused dust storm in the region which has huge economic and health consequences on the inhabitants. The flow of the Hirmand (or Helmand) River, the most important feeding river, has decreased from 4 to 1.9 km3 downstream due to anthropogenic activities. In this basin, water is mainly consumed for farming. Due to the lack of in-situ data in the basin, this research utilizes remote-sensing data to show how croplands and consequently consumed water in the agricultural sector have changed. Based on Landsat NDVI, we suggest using a threshold of around 0.35-0.4 to detect croplands in the basin. Croplands of this basin has doubled since 1990, especially in the downstream of the Kajaki Dam (the biggest dam of the basin). Using PML V2 Actual Evapotranspiration (AET) data and considering irrigation efficiency (≈0.3), we estimate that the consumed water (CW) for farming. We found that CW has increased from 2.5 to over 7.5 km3 from 2002 to 2017 in this basin. Also, the annual average Potential Evapotranspiration (PET) of the basin has had a negative trend in the recent years, although the AET over croplands has an increasing trend. In this research, using remote sensing data, we covered lack of data in the studied area and highlighted anthropogenic activities in the upstream which led to the lakes desiccation in the downstream.

Keywords: Afghanistan-Iran transboundary Basin, Iran-Afghanistan water treaty, water use, lake desiccation

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Authors: Henry Navarro, Martin Sirena, Nestor Haberkorn

Abstract:

We report the electrical transport through voltage-current curves (I-V) in tunnels junction GdBa₂Cu₃O₇-d/ insulator/ GdBa₂Cu₃O₇-d, and Nb/insulator/ GdBa₂Cu₃O₇-d is analyzed using a conducting atomic force microscope (CAFM) at room temperature. The measurements were obtained on tunnel junctions with different areas (900 μm², 400 μm² and 100 μm²). Trilayers with GdBa₂Cu₃O₇-d (GBCO) as the bottom electrode, SrTiO₃ (STO) or BaTiO₃ (BTO) as the insulator barrier (thicknesses between 1.6 nm and 4 nm), and GBCO or Nb as the top electrode were grown by DC sputtering on (100) SrTiO₃ substrates. For STO and BTO barriers, asymmetric IV curves at positive and negative polarization can be obtained using electrodes with different work function. The main difference is that the BTO is a ferroelectric material, while in the STO the ferroelectricity can be produced by stress or deformation at the interfaces. In addition, hysteretic IV curves are obtained for BTO barriers, which can be ascribed to a combined effect of the FE reversal switching polarization and an oxygen vacancy migration. For GBCO/ BTO/ GBCO heterostructures, the IV curves correspond to that expected for asymmetric interfaces, which indicates that the disorder affects differently the properties at the bottom and top interfaces. Our results show the role of the interface disorder on the electrical transport of conducting/ insulator/ conduction heterostructures, which is relevant for different applications, going from resistive switching memories (at room temperature) to Josephson junctions (at low temperatures). The superconducting transition of the GBCO electrode was characterized by electrical transport using the 4-prong configuration with low density of topological defects and with Tc over liquid N₂ can be obtained for thicknesses of 16 nm, our results demonstrate that GBCO films with an average root-mean-square (RMS) smaller than 1 nm and areas (up 100 um²) free of 3-D topological defects can be obtained.

Keywords: thin film, sputtering, conductive atomic force microscopy, tunnel junctions

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