Search results for: recovery energy

Authors: M. I. Equbal, R. K. Ohdar, B. Singh, P. Talukdar

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Micro-alloyed steel components are used in automotive industry for the necessity to make the manufacturing process cycles shorter when compared to conventional steel by eliminating heat treatment cycles, so an important saving of costs and energy can be reached by reducing the number of operations. Micro-alloying elements like vanadium, niobium or titanium have been added to medium carbon steels to achieve grain refinement with or without precipitation strengthening along with uniform microstructure throughout the matrix. Present study reports the applicability of medium carbon vanadium micro-alloyed steel in hot forging. Forgeability has been determined with respect to different cooling rates, after forging in a hydraulic press at 50% diameter reduction in temperature range of 900-11000C. Final microstructures, hardness, tensile strength, and impact strength have been evaluated. The friction coefficients of different lubricating conditions, viz., graphite in hydraulic oil, graphite in furnace oil, DF 150 (Graphite, Water-Based) die lubricant and dry or without any lubrication were obtained from the ring compression test for the above micro-alloyed steel. Results of ring compression tests indicate that graphite in hydraulic oil lubricant is preferred for free forging and dry lubricant is preferred for die forging operation. Exceptionally good forgeability and high resistance to fracture, especially for faster cooling rate has been observed for fine equiaxed ferrite-pearlite grains, some amount of bainite and fine precipitates of vanadium carbides and carbonitrides. The results indicated that the cooling rate has a remarkable effect on the microstructure and mechanical properties at room temperature.

Keywords: cooling rate, hot forging, micro-alloyed, ring compression

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Authors: M. Abdoos, A. Amadeh, M. Adabi

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In recent decades, the use of titanium and its alloys due to their high mechanical properties, light weight and their corrosion resistance has increased in military and industry applications. However, the poor surface properties can limit their widely usage. Many researches were carried out to improve their surface properties. The most effective technique is based on solid-state diffusion of elements that can form intermetallic compounds with the substrate. In the present work, inter-diffusion of nickel and titanium and formation of Ni-Ti intermetallic compounds in nickel-coated Ti-6Al-4V alloy have been studied. Initially, nickel was electrodeposited on the alloy using Watts bath at a current density of 20 mA/cm2 for 1 hour. The coated specimens were then heat treated in a tubular furnace under argon atmosphere at different temperatures near Ti β-transus to maximize the diffusion rate for various durations in order to improve the surface properties of the Ti-6Al-4V alloy. The effect of temperature and time on the thickness of diffusion layer and characteristics of intermetallic phases was studied by means of scanning electron microscope (SEM) equipped with energy dispersive X-ray spectrometer (EDS) and microhardness test. The results showed that a multilayer structure was formed after heat treatment: an outer layer of remaining nickel, an area of intermetallic layers with different compositions and solid solution of Ni-Ti. Three intermetallic layers was detected by EDS analysis, namely an outer layer with about 75 at.% Ni (Ni3Ti), an intermediate layer with 50 at.% Ni (NiTi) and finally an inner layer with 36 at.% Ni (NiTi2). It was also observed that the increase in time or temperature led to the formation of thicker intermetallic layers. Meanwhile, the microhardness of heat treated samples increased with formation of Ni-Ti intermetallics; however, its value depended on heat treatment parameters.

Keywords: heat treatment, microhardness, Ni coating, Ti-6Al-4V

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Authors: Ziying Wu, Danfeng Yan

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Multi-Access Edge Computing (MEC) is one of the key technologies of the future 5G network. By deploying edge computing centers at the edge of wireless access network, the computation tasks can be offloaded to edge servers rather than the remote cloud server to meet the requirements of 5G low-latency and high-reliability application scenarios. Meanwhile, with the development of IOV (Internet of Vehicles) technology, various delay-sensitive and compute-intensive in-vehicle applications continue to appear. Compared with traditional internet business, these computation tasks have higher processing priority and lower delay requirements. In this paper, we design a 5G-based Vehicle-Aware Multi-Access Edge Computing Network (VAMECN) and propose a joint optimization problem of minimizing total system cost. In view of the problem, a deep reinforcement learning-based joint computation offloading and task migration optimization (JCOTM) algorithm is proposed, considering the influences of multiple factors such as concurrent multiple computation tasks, system computing resources distribution, and network communication bandwidth. And, the mixed integer nonlinear programming problem is described as a Markov Decision Process. Experiments show that our proposed algorithm can effectively reduce task processing delay and equipment energy consumption, optimize computing offloading and resource allocation schemes, and improve system resource utilization, compared with other computing offloading policies.

Keywords: multi-access edge computing, computation offloading, 5th generation, vehicle-aware, deep reinforcement learning, deep q-network

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Authors: P. Abachi, T. W. Coyle, P. S. Musavi Gharavi

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By applying coating onto a structural component, the corrosion and/or wear resistance requirements of the surface can be fulfilled. Since the layer adhesion of the coating influences the mechanical integrity of the coat/substrate interface during the service time, it should be examined accurately. At the present work, the tensile bonding strength of the 316 stainless steel plasma sprayed coating on aluminum substrate was determined by using tensile adhesion test, TAT, specimen. The interfacial fracture toughness was specified using four-point bend specimen containing a saw notch and modified chevron-notched short-bar (SB) specimen. The coating microstructure and fractured specimen surface were examined by using scanning electron- and optical-microscopy. The investigation of coated surface after tensile adhesion test indicates that the failure mechanism is mostly cohesive and rarely adhesive type. The calculated value of critical strain energy release rate proposes relatively good interface status. It seems that four-point bending test offers a potentially more sensitive means for evaluation of mechanical integrity of coating/substrate interfaces than is possible with the tensile test. The fracture toughness value reported for the modified chevron-notched short-bar specimen testing cannot be taken as absolute value because its calculation is based on the minimum stress intensity coefficient value which has been suggested for the fracture toughness determination of homogeneous parts in the ASTM E1304-97 standard. 

Keywords: bonding strength, four-point bend test, interfacial fracture toughness, modified chevron-notched short-bar specimen, plasma sprayed coating, tensile adhesion test

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Authors: Alireza Jalalvand, Maryam Saleh, Somayeh Behjat Khatouni, Zahra Bahri Najafi, Foroozan Fatahinia, Narges Ismailzadeh, Behrokh Farahmand

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Object: In the last two decades, the recent outbreak of Coronavirus (SARS-CoV-2) imposed a global pandemic in the world. Despite the increasing prevalence of the disease, there are no effective drugs to treat it. A suitable and rapid way to afford an effective drug and treat the global pandemic is a computational drug study. This study used molecular docking methods to examine the potential inhibition of over 50 antiviral drugs against three fundamental proteins of SARS-CoV-2. METHODS: Through a literature review, three important proteins (a key protease, RNA-dependent RNA polymerase (RdRp), and spike) were selected as drug targets. Three-dimensional (3D) structures of protease, spike, and RdRP proteins were obtained from the Protein Data Bank. Protein had minimal energy. Over 50 antiviral drugs were considered candidates for protein inhibition and their 3D structures were obtained from drug banks. The Autodock 4.2 software was used to define the molecular docking settings and run the algorithm. RESULTS: Five drugs, including indinavir, lopinavir, saquinavir, nelfinavir, and remdesivir, exhibited the highest inhibitory potency against all three proteins based on the binding energies and drug binding positions deduced from docking and hydrogen-bonding analysis. Conclusions: According to the results, among the drugs mentioned, saquinavir and lopinavir showed the highest inhibitory potency against all three proteins compared to other drugs. It may enter laboratory phase studies as a dual-drug treatment to inhibit SARS-CoV-2.

Keywords: covid-19, drug repositioning, molecular docking, lopinavir, saquinavir

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Authors: Muhammad Arif Jalil, Somchat Sonasang, Preecha Yupapin

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This study hypothesizes that the universe is at the center of the universe among the white and black holes, which are the entangled pairs. The coupling between them is in terms of spacetime forming the universe and things. The birth of things is based on exchange energy between the white and black sides. That is, the transition from the white side to the black side is called wave-matter, where it has a speed faster than light with positive gravity. The transition from the black to the white side has a speed faster than light with negative gravity called a wave-particle. In the part where the speed is equal to light, the particle rest mass is formed. Things can appear to take shape here. Thus, the gravity is zero because it is the center. The gravitational force belongs to the Earth itself because it is in a position that is twisted towards the white hole. Therefore, it is negative. The coupling of black-white holes occurs directly on both sides. The mass is formed at the saturation and will create universes and other things. Therefore, it can be hundreds of thousands of universes on both sides of the B and white holes before reaching the saturation point of multi-universes. This work will use the DJV circuit that the research team made as an entangled or two-level system circuit that has been experimentally demonstrated. Therefore, this principle has the possibility for interpretation. This work explains the emergence of multiple universes and can be applied as a practical guideline for searching for universes in the future. Moreover, the results indicate that the DJV circuit can create the elementary particles according to Feynman's diagram with rest mass conditions, which will be discussed for fission and fusion applications.

Keywords: multi-universes, feynman diagram, fission, fusion

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Authors: Juan Manuel Uriarte Lopez, Hector Raul Guemez Gaxiola, Javier Alonso Romo Rubio, Juan Manuel Romo Valdez

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The objective of this investigation was to determine the influence of the use of recycled vegetable oil from restaurants in the productive performance of sows in lactation. Twenty-four hybrids lactating sows (Landrace x Yorkshire) were divided into three treatments with eight sows per treatment. On day 107 of gestation, the sows were moved to the mesh floor maternity cages in an environment regulated by the environment regulated (2.4 × 0.6 m) contained an area (2.4 × 0.5 m) for newborn pigs on each side, all diets were provided as a dry powder, and the sows received free access to water throughout the experimental period. After farrowing, the sows were fasted for 12 hours, the daily feed ration gradually increased, and the sows had ad libitum access to feed on the fourth day. The diets used were corn-soybean meal-based, containing 0 (CONT), recycled vegetable oil 1.0 % (RVOL), or recycled vegetable oil 1.5 % (RVOH) for 30 days. The diets contained similar calculated levels of crude protein and metabolizable energy and contained vitamins and minerals that exceeded National Research Council (1998) recommendations; sows were fed three times daily. On day 30, piglets were weaned, and performances of lactating sows and nursery piglets were recorded. Results indicated that average daily feed intake (5.58, 5.55, and 5.49 kg for CONT, RVOL, and RVO, respectively) of sows were not affected (P > 0.05) by different dietary. There was no difference in the average body weight of piglets on the day of birth, with 1.33, 1.36, and 1.35 kg, respectively (P > 0.05). There was no difference in average body weight of piglets on day 30, with 6.91, 6.75, and 7.05 kg, respectively 0.05) between treatments numbers of weaned piglets per sow (9.95, 9.80, and 9.80) were not affected by treatments (P > 0.05).In conclusion, the substitution of virgin vegetable oil for recycled vegetable oil in the diet does not affect the productive performance of lactating sows.

Keywords: lactating, sow, vegetable, oil

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Authors: Savvas Varitis, Panagiotis Kavouras, George Vourlias, Eleni Pavlidou, Theodoros Karakostas, Philomela Komninou

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A chromium-loaded ash originating from incineration of tannery sludge under anoxic conditions was mixed with low grade soda-lime glass powder coming from commercial glass bottles. The relative weight proportions of ash over glass powder tested were 30/70, 40/60 and 50/50. The solid mixtures, formed in green state compacts, were sintered at the temperature range of 800oC up to 1200oC. The resulting products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDXS) and micro-indentation. The above methods were employed to characterize the various phases, microstructure and hardness of the produced materials. Thermal treatment at 800oC and 1000oC produced opaque ceramic products composed of a variety of chromium-containing and chromium-free crystalline phases. Thermal treatment at 1200oC gave rise to composite products, where only chromium-containing crystalline phases were detected. Hardness results suggest that specific products are serious candidates for structural applications. Acknowledgement: This research has been co-financed by the European Union (European Social Fund – ESF) and Greek national funds through the Operational Program “Education and Lifelong Learning” of the National Strategic Reference Framework (NSRF) – Research Funding Program: THALES “WasteVal”: Reinforcement of the interdisciplinary and/or inter-institutional research and innovation.

Keywords: chromium-rich tannery residues, glass-ceramic materials, mechanical properties, microstructure

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Authors: P. Wongmatar, C. Hansapinyo, C. Buachart

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Failure of typical seismic frames has been found by plastic hinge occurring on beams section near column faces. Past researches shown that the seismic capacity of the frames can be enhanced if the plastic hinges of the beams are shifted away from the column faces. This paper presents detailing of reinforcements in the interior beam–column connections aiming to relocate the plastic hinge of reinforced concrete and precast concrete frames. Four specimens were tested under quasi-static cyclic load including two monolithic specimens and two precast specimens. For one monolithic specimen, typical seismic reinforcement was provided and considered as a reference specimen named M1. The other reinforced concrete frame M2 contained additional intermediate steel in the connection area compared with the specimen M1. For the precast specimens, embedded T-section steels in joint were provided, with and without diagonal bars in the connection area for specimen P1 and P2, respectively. The test results indicated the ductile failure with beam flexural failure in monolithic specimen M1 and the intermediate steel increased strength and improved joint performance of specimen M2. For the precast specimens, cracks generated at the end of the steel inserts. However, slipping of reinforcing steel lapped in top of the beams was seen before yielding of the main bars leading to the brittle failure. The diagonal bars in precast specimens P2 improved the connection stiffness and the energy dissipation capacity.

Keywords: relocation, plastic hinge, intermediate bar, T-section steel, precast concrete frame

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Authors: K. Meera Saheb, K. Krishna Bhaskar

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Complex structures used in many fields of engineering are made up of simple structural elements like beams, plates etc. These structural elements, sometimes carry concentrated masses at discrete points, and when subjected to severe dynamic environment tend to vibrate with large amplitudes. The frequency amplitude relationship is very much essential in determining the response of these structural elements subjected to the dynamic loads. For Timoshenko beams, the effects of shear deformation and rotary inertia are to be considered to evaluate the fundamental linear and nonlinear frequencies. A commonly used method for solving vibration problem is energy method, or a finite element analogue of the same. In the present Coupled Displacement Field method the number of undetermined coefficients is reduced to half when compared to the famous Rayleigh Ritz method, which significantly simplifies the procedure to solve the vibration problem. This is accomplished by using a coupling equation derived from the static equilibrium of the shear flexible structural element. The prime objective of the present paper here is to study, in detail, the effect of a central concentrated mass on the large amplitude free vibrations of uniform shear flexible beams. Accurate closed form expressions for linear frequency parameter for uniform shear flexible beams with a central concentrated mass was developed and the results are presented in digital form.

Keywords: coupled displacement field, coupling equation, large amplitude vibrations, moderately thick plates

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Authors: Ratnakumar V. Kappagantula, Gordon D. Ingram, Hari B. Vuthaluru

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This paper analyzes a three reactor chemical looping process for hydrogen production from natural gas, allowing for carbon dioxide capture through chemical looping technology. An oxygen carrier is circulated to separate carbon dioxide, to reduce steam for hydrogen production and to supply oxygen for combustion. In this study, the emphasis is placed on the steam conversion in the steam reactor by investigating the hydrogen efficiencies of the complete system at steam conversions of 15.8% and 50%. An Aspen Plus model was developed for a Three Reactor Chemical Looping process to study the effects of operational parameters on hydrogen production is investigated. Maximum hydrogen production was observed under stoichiometric conditions. Different conversions in the steam reactor, which was modelled as a Gibbs reactor, were found when Gibbs-identified products and user identified products were chosen. Simulations were performed for different oxygen carriers, which consist of an active metal oxide on an inert support material. For the same metal oxide mass flowrate, the fuel reactor temperature decreased for different support materials in the order: aluminum oxide (Al2O3) > magnesium aluminate (MgAl2O4) > zirconia (ZrO2). To achieve the same fuel reactor temperature for the same oxide mass flow rate, the inert mass fraction was found to be 0.825 for ZrO2, 0.7 for MgAl2O4 and 0.6 for Al2O3. The effect of poisoning of the oxygen carrier was also analyzed. With 3000 ppm sulfur-based impurities in the feed gas, the hydrogen product energy rate of the process were found to decrease by 0.4%.

Keywords: aspen plus, chemical looping combustion, inert support balls, oxygen carrier

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Authors: Saumya R. Jha, Krishanu Biswas, Nilesh P. Gurao

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Several recent investigations have revealed medium entropy alloys exhibiting better mechanical properties than their high entropy counterparts. This clearly establishes that although a higher entropy plays a vital role in stabilization of particular phase over complex intermetallic phases, configurational entropy is not the primary factor responsible for the high inherent strengthening in these systems. Above and beyond a high contribution from friction stresses and solid solution strengthening, strain hardening is an important contributor to the strengthening in these systems. In this regard, researchers have developed severe plastic deformation (SPD) techniques like High Pressure Torsion (HPT) to incorporate very high shear strain in the material, thereby leading to ultrafine grained (UFG) microstructures, which cause manifold increase in the strength. The presented work demonstrates a meticulous study of the variation in mechanical properties at different radial displacements from the center of HPT tested equiatomic ternary FeMnNi synthesized by casting route, which is a low stacking fault energy FCC alloy that shows significantly higher toughness than its high entropy counterparts like Cantor alloy. The gradient in grain sizes along the radial direction of these specimens has been modeled using microstructure entropy for predicting the mechanical properties, which has also been validated by indentation tests. The dislocation density is computed by FEM simulations for varying strains and validated by analyzing synchrotron diffraction data. Thus, the proposed model can be utilized to predict the strengthening behavior of similar systems deformed by HPT subjected to varying loading conditions.

Keywords: high pressure torsion, severe plastic deformation, configurational entropy, dislocation density, FEM simulation

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Authors: J. S. Saini, P. P. K. Sandhu

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The multi-hop nature of Wireless Mesh Networks and the hasty progression of throughput demands results in multi- channels and multi-radios structures in mesh networks, but the main problem of co-channels interference reduces the total throughput, specifically in multi-hop networks. Quality of Service mentions a vast collection of networking technologies and techniques that guarantee the ability of a network to make available desired services with predictable results. Quality of Service (QoS) can be directed at a network interface, towards a specific server or router's performance, or in specific applications. Due to interference among various transmissions, the QoS routing in multi-hop wireless networks is formidable task. In case of multi-channel wireless network, since two transmissions using the same channel may interfere with each other. This paper has considered the Destination Sequenced Distance Vector (DSDV) routing protocol to locate the secure and optimised path. The proposed technique also utilizes the Lempel–Ziv–Welch (LZW) based lossless data compression and intra cluster data aggregation to enhance the communication between the source and the destination. The use of clustering has the ability to aggregate the multiple packets and locates a single route using the clusters to improve the intra cluster data aggregation. The use of the LZW based lossless data compression has ability to reduce the data packet size and hence it will consume less energy, thus increasing the network QoS. The MATLAB tool has been used to evaluate the effectiveness of the projected technique. The comparative analysis has shown that the proposed technique outperforms over the existing techniques.

Keywords: WMNS, QOS, flooding, collision avoidance, LZW, congestion control

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Authors: P. Acosta-Santamaría, A. Ibatá-Soto, A. López-Vásquez

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Organic compounds in wastewaters coming from textile and pharmaceutical industry generated multiple harmful effects on the environment and the human health. One of them is the methyl orange (MeO), an azoic dye considered to be a recalcitrant compound. The heterogeneous photocatalysis emerges as an alternative for treating this type of hazardous compounds, through the generation of OH radicals using radiation and a semiconductor oxide. According to the author’s knowledge, catalysts such as TiO₂ doped with metals show high efficiency in degrading MeO; however, this presents economic limitations on industrial scale. Black sand can be considered as a naturally doped catalyst because in its structure is common to find compounds such as titanium, iron and aluminum oxides, also elements such as zircon, cadmium, manganese, etc. This study reports the photocatalytic activity of the mineral black sand used as semiconductor in the discoloration of MeO by oxidation and reduction photocatalytic techniques. For this, magnetic composites from the mineral were prepared (RM, M1, M2 and NM) and their activity were tested through MeO discoloration while TiO₂ was used as reference. For the fractions, chemical, morphological and structural characterizations were performed using Scanning Electron Microscopy with Energy Dispersive X-Ray (SEM-EDX), X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) analysis. M2 fraction showed higher MeO discoloration (93%) in oxidation conditions at pH 2 and it could be due to the presence of ferric oxides. However, the best result to reduction process was using M1 fraction (20%) at pH 2, which contains a higher titanium percentage. In the first process, hydrogen peroxide (H₂O₂) was used as electron donor agent. According to the results, black sand mineral can be used as natural semiconductor in photocatalytic process. It could be considered as a photocatalyst precursor in such processes, due to its low cost and easy access.

Keywords: black sand mineral, methyl orange, oxidation, photocatalysis, reduction

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Authors: Fairuz A. Ulinnuha, Bimo K. Fuadi

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The world’s population continues to grow resulting in steady migration from rural to urban areas. Increased numbers of people and cities hand in hand with greater exploitation of world’s resource. Every year, more cities are feeling the devastating of this impact of this situation. During the 1970’s, some of eco-concept were applied to urban settings, one of them is Ecological Cities. A non-profit organization, Urban Ecology, was founded in California in 1975 to 'rebuild cities in balance with nature'. Efforts to synthesize ecological and urban planning approaches were slowed somewhat in the 1980s, but useful refinements were made. Consideration of social impact acknowledges that the ecological design is not just about ecology itself. It is also about questioning and redefining our understanding of the ecology. When ecologist did recognize the existence of cities, they were usually concerned with resource flows. One popular approach was to study the flow and transformation of energy through urban ecosystem. This research method is descriptive method, following LEED Certification which is the international standard of the sustainable building, is more widely applied. But there remains problem that the moral imperative of sustainability and by implication of sustainable design, tends to supplant the disciplinary contribution. Sustainable design is not always seen as design excellence or design innovation. This can provoke the skepticism and cause the tension those who promote disciplinary knowledge and those who push for sustainability. The challenges of rapid urbanization and limited of global resources has become more pressing. So, there is a need to find an alternative design approaches. The urban, as the site of complex relation (economy, political, social, cultural), need a complex problem solving that can solve current and future condition. The aim of this study is to discussed about conjoining of ecology such as public park and sustainable design.

Keywords: ecology, cities, urban, sustainability

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Authors: Mehmet Akif Bütüner, İlhan Koşalay

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Hydroelectric power plants (HEPPs) are renewable energy power plants with the highest installed power in the world. While the control systems operating in these power plants ensure that the system operates at the desired operating point, it is also responsible for stopping the relevant unit safely in case of any malfunction. While these control systems are expected not to miss signals that require stopping, on the other hand, it is desired not to cause unnecessary stops. In traditional control systems including modern systems with SCADA infrastructure, alarm conditions to create warnings or trip conditions to put relevant unit out of service automatically are usually generated with predefined limits regardless of different operating conditions. This approach results in alarm/trip conditions to be less likely to detect minimal changes which may result in serious malfunction scenarios in near future. With the methods proposed in this research, routine behavior of the oil circulation of hydraulic governor of a HEPP will be modeled with machine learning methods using historical data obtained from SCADA system. Using the created model and recently gathered data from control system, oil pressure of hydraulic accumulators will be estimated. Comparison of this estimation with the measurements made and recorded instantly by the SCADA system will help to foresee failure before becoming worse and determine remaining useful life. By using model outputs, maintenance works will be made more planned, so that undesired stops are prevented, and in case of any malfunction, the system will be stopped or several alarms are triggered before the problem grows.

Keywords: hydroelectric, governor, anomaly detection, machine learning, regression

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Authors: Krishna Prasad Maity, Narendra Tanty, Ananya Patra, V. Prasad

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Carbon nanotube (CNT) is a well-known material for very good electrical, thermal conductivity and high tensile strength. Because of that, it’s widely used in many fields like nanotechnology, electronics, optics, etc. In last two decades, polyaniline (PANI) with CNT and functionalized CNT (fCNT) have been promising materials in application of gas sensing, electromagnetic shielding, electrode of capacitor etc. So, the study of electrical conductivity of PANI/CNT and PANI/fCNT is important to understand the charge transport and interaction between PANI and CNT in the composite. It is observed that a transition in magnetoresistance (MR) with lowering temperature, increasing magnetic field and decreasing CNT percentage in CNT/PANI composite. Functionalization of CNT prevent the nanotube aggregation, improves interfacial interaction, dispersion and stabilized in polymer matrix. However, it shortens the length, breaks C-C sp² bonds and enhances the disorder creating defects on the side walls. We have studied electrical resistivity and MR in PANI with CNT and fCNT composites for different weight percentages down to the temperature 4.2K and up to magnetic field 5T. Resistivity increases significantly in composite at low temperature due to functionalization of CNT compared to only CNT. Interestingly a transition from negative to positive magnetoresistance has been observed when the filler is changed from pure CNT to functionalized CNT after a certain percentage (10wt%) as the effect of more disorder in fCNT/PANI composite. The transition of MR has been explained on the basis of polaron-bipolaron model. The long-range Coulomb interaction between two polarons screened by disorder in the composite of fCNT/PANI, increases the effective on-site Coulomb repulsion energy to form bipolaron which leads to change the sign of MR from negative to positive.

Keywords: coulomb interaction, magnetoresistance transition, polyaniline composite, polaron-bipolaron

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Authors: Romeo Malik, Yashraj Tripathy, Anup Barai

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Transportation safety is a major concern for vehicle electrification on a large-scale. The failure cost of lithium-ion batteries is substantial and is significantly impacted by higher liability and replacement cost. With continuous advancement on the material front in terms of higher energy density, upgrading safety characteristics are becoming more crucial for broader integration of lithium-ion batteries. Understanding and impeding thermal runaway is the prime issue for battery safety researchers. In this study, a comprehensive comparison of thermal runaway mechanisms for two different cathode types, Li(Ni₀.₃Co₀.₃Mn₀.₃)O₂ and Li(Ni₀.₈Co₀.₁₅Al₀.₀₅)O₂ is explored. Both the chemistries were studied for different states of charge, and the various abuse scenarios that lead to thermal runaway is investigated. Abuse tests include mechanical abuse, electrical abuse, and thermal abuse. Batteries undergo thermal runaway due to a series of combustible reactions taking place internally; this is observed as multiple jets of flame reaching temperatures of the order of 1000ºC. The physicochemical characterisation was performed on cells, prior to and after abuse. Battery’s state of charge and chemistry have a significant effect on the flame temperature profiles which is otherwise quantified as heat released. Majority of the failures during transportation is due to these external short circuit. Finally, a mitigation approach is proposed to impede the thermal runaway hazard. Transporting lithium-ion batteries under low states of charge is proposed as a way forward. Batteries at low states of charge have demonstrated minimal heat release under thermal runaway reducing the risk of secondary hazards such as thermal runaway propagation.

Keywords: battery reliability, lithium-ion batteries, thermal runaway characterisation, tomography

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Authors: Hafiz Arbab Sakandar

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Time-restricted intermittent fasting (TRIF) impacts host’s physiology and health. Plenty of health benefits have been reported for TRIF in animal models. However, limited studies have been conducted on humans especially in underdeveloped economies. Here, we designed a study to investigate the impact of TRIF/Ramadan fasting (16:8) on the modulation of gut-microbiome structure, metabolic pathways, and predicted metabolites and explored the correlation among them at different time points (during and after the month of Ramadan) in Pakistani Expats living in China. We observed different trends of Shannon-Wiener index in different subjects; however, all subjects showed substantial change in bacterial diversity with the progression of TRIF. Moreover, the changes in gut microbial structure by the end of TRIF were higher vis-a-vis in the beginning, significant difference was observed among individuals. Additionally, metabolic pathways analysis revealed that amino acid, carbohydrate and energy metabolism, glycan biosynthesis metabolism of cofactors and vitamins were significantly affected by TRIF. Pyridoxamine, glutamate, citrulline, arachidonic acid, and short chain fatty acid showed substantial difference at different time points based on the predicted metabolism. In conclusion, these results contribute to further our understanding about the key relationship among, dietary intervention (TRIF), gut microbiome structure and function. The preliminary results from study demonstrate significant potential for elucidating the mechanisms underlying gut microbiome stability and enhancing the effectiveness of microbiome-tailored interventions among the Pakistani populace. Nonetheless, extensive, and rigorous large-scale research on the Pakistani population is necessary to expound on the association between diet, gut microbiome, and overall health.

Keywords: gut microbiome, health, fasting, functionality

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Authors: L. K. Nivedha, V. Maruthapandian, R. Kothandaraman

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Rechargeable zinc-air batteries (ZAB) are gaining significant research attention owing to their high energy density and copious zinc resources worldwide. However, the unsolved obstacles such as dendrites, passivation, depth of discharge and the lack of an efficient cathode catalyst restrict their practical application1. By and large, non-noble transition metal-based catalysts are well-reputed materials for catalysing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with greater stability in alkaline medium2. Herein, we report the synthesis and application of Mn₃O4-NiFeLDH/Carbon composite as a cathode catalyst for rechargeable ZAB. The synergetic effects of the mixed transition metals (Mn/Ni/Fe) have aided in catalysing ORR and OER in alkaline electrolyte with a shallow potential gap of 0.7 V. The composite, by its distinctive physicochemical characteristics, shows an excellent OER activity with a current density of 1.5 mA cm⁻² at a potential of 1.6 V and a superior ORR activity with an onset potential of 0.8 V when compared with their counterparts. Nevertheless, the catalyst prefers a two-electron pathway for the electrochemical reduction of oxygen which results in a limiting current density of 2.5 mA cm⁻². The bifunctional activity of the Mn₃O₄-NiFeLDH/Carbon composite was utilized in developing rechargeable ZAB. The fully fabricated ZAB delivers an open circuit voltage of 1.4 V, a peak power density of 70 mW cm⁻², and a specific capacity of 800 mAh g⁻¹ at a current density of 20 mA cm⁻² with an average discharge voltage of 1 V and the cell is operable upto 50 mA cm-2. Rechargeable ZAB demonstrated over 110 h at 10 mA cm⁻². Further, the cause for the diminished charge-discharge performance experienced beyond the 100th cycle was investigated, and carbon corrosion was testified using Infrared spectroscopy.

Keywords: rechargeable zinc-air battery, oxygen evolution reaction, bifunctional catalyst, alkaline medium

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Authors: Mohamed Edokali, Robert Menzel, David Harbottle, Ali Hassanpour

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Forward osmosis (FO) process has stood out as an energy-efficient technology for water desalination and purification, although the practical application of FO for desalination still relies on RO-based Thin Film Composite (TFC) and Cellulose Triacetate (CTA) polymeric membranes which have a low performance. Recently, graphene oxide (GO) laminated membranes have been considered an ideal selection to overcome the bottleneck of the FO-polymeric membranes owing to their simple fabrication procedures, controllable thickness and pore size and high water permeability rates. However, the low stability of GO laminates in wet and harsh environments is still problematic. The recent developments of modified GO and hydrophobic reduced graphene oxide (rGO) membranes for FO desalination have demonstrated attempts to overcome the ongoing trade-off between desalination performance and stability, which is yet to be achieved prior to the practical implementation. In this study, acid-functionalized GO nanosheets cooperatively reduced and crosslinked by the hyperbranched polyethyleneimine (PEI) and polyethylene glycol (PEG) polymers, respectively, are applied for fabrication of the FO membrane, to enhance the membrane stability and performance, and compared with other functionalized rGO-FO membranes. PEI/PEG doped rGO membrane retained two compacted d-spacings (0.7 and 0.31 nm) compared to the acid-functionalized GO membrane alone (0.82 nm). Besides increasing the hydrophilicity, the coating layer of PEG onto the PEI-doped rGO membrane surface enhanced the structural integrity of the membrane chemically and mechanically. As a result of these synergetic effects, the PEI/PEG doped rGO membrane exhibited a water permeation of 7.7 LMH, salt rejection of 97.9 %, and reverse solute flux of 0.506 gMH at low flow rates in the FO desalination process.

Keywords: desalination, forward osmosis, membrane performance, polyethyleneimine, polyethylene glycol, reduced graphene oxide, stability

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Authors: Adela Penesova, Zofia Radikova, Boris Bajer, Andrea Havranova, Miroslav Vlcek

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Background: The aim of our study was to compare the effect of intensified lifestyle intervention on insulin resistance (HOMA-IR), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and Fibroblast growth factor (FGF) 21 after 8 weeks of lifestyle intervention. Methods: A group of 43 obese patients (13M/30F; 43.0±12.4 years; BMI (body mass index) 31.2±6.3 kg/m2 participated in a weight loss interventional program (NCT02325804) following an 8-week hypocaloric diet (-30% energy expenditure) and physical activity 150 minutes/week. Insulin sensitivity was evaluated according to the homeostasis model assessment of insulin resistance (HOMA-IR) and insulin sensitivity indices according to Matsuda and Cederholm were calculated (ISImat and ISIced). Plasma ALT, AST, Fetuin-A, FGF 21, and physical fitness were measured. Results: The average reduction of body weight was 6.8±4.9 kg (0-15 kg; p=0.0006), accompanied with a significant reduction of body fat amount of fat mass (p=0.03), and waist circumference (p=0.02). Insulin sensitivity has been improved (IR HOMA 2.71±3.90 vs 1.24±0.83; p=0.01; ISIMat 6.64±4.38 vs 8.93±5.36 p ≤ 0.001). Total, LDL cholesterol, and triglycerides decreased (p=0.05, p=0.04, p=0.04, respectively). Physical fitness significantly improved after intervention (as measure VO2 max (maximal oxygen uptake) (p ≤ 0.001). ALT decreased significantly (0.44±0.26 vs post 0.33±0.18 ukat/l, p=0.004); however, AST not (pre 0.40±0.15 vs 0.35±0.09 ukat/l, p=0.07). Hepatokine Fetuin-A significantly decreased after intervention (43.1±10.8 vs 32.6±8.6 ng/ml, p < 0.001); however, FGF 21 levels tended to decrease (146±152 vs 132±164 pg/ml, p=0.07). Conclusion: 8-weeks of diet and physical activity intervention program in obese otherwise healthy subjects led to an improvement of insulin resistance parameters and liver marker profiles, as well as increased physical fitness. This study was supported by grants APVV 15-0228; VEGA 2/0161/16.

Keywords: obesity, diet, exercice, insulin sensitivity

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Authors: Bienvenu Gael Fouda Mbanga

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This study reports a new approach of preparation of carbon nanoparticles coated cerium oxide nanorods (CNPs/CeONRs) nanocomposite and reusing the spent adsorbent of Cd2+- CNPs/CeONRs nanocomposite for latent fingerprint detection (LFP) after removing Cd2+ ions from aqueous solution. CNPs/CeONRs nanocomposite was prepared by using CNPs and CeONRs with adsorption processes. The prepared nanocomposite was then characterized by using UV-visible spectroscopy (UV-visible), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction pattern (XRD), scanning electron microscope (SEM), Transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy (EDS), Zeta potential, X-ray photoelectron spectroscopy (XPS). The average size of the CNPs was 7.84nm. The synthesized CNPs/CeONRs nanocomposite has proven to be a good adsorbent for Cd2+ removal from water with optimum pH 8, dosage 0. 5 g / L. The results were best described by the Langmuir model, which indicated a linear fit (R2 = 0.8539-0.9969). The adsorption capacity of CNPs/CeONRs nanocomposite showed the best removal of Cd2+ ions with qm = (32.28-59.92 mg/g), when compared to previous reports. This adsorption followed pseudo-second order kinetics and intra particle diffusion processes. ∆G and ∆H values indicated spontaneity at high temperature (40oC) and the endothermic nature of the adsorption process. CNPs/CeONRs nanocomposite therefore showed potential as an effective adsorbent. Furthermore, the metal loaded on the adsorbent Cd2+- CNPs/CeONRs has proven to be sensitive and selective for LFP detection on various porous substrates. Hence Cd2+-CNPs/CeONRs nanocomposite can be reused as a good fingerprint labelling agent in LFP detection so as to avoid secondary environmental pollution by disposal of the spent adsorbent.

Keywords: Cd2+-CNPs/CeONRs nanocomposite, cadmium adsorption, isotherm, kinetics, thermodynamics, reusable for latent fingerprint detection

Procedia PDF Downloads 119

Authors: Natacha Fery, Guilherme L. Dalledonne, Xiangyang Zheng, Cheng Tang, Roberto Mayerle

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A Decision Support System (DSS) for supporting decision makers in the management of the Shandong Peninsula has been developed. Emphasis has been given to coastal protection, coastal cage aquaculture and harbors. The investigations were done in the framework of a joint research project funded by the German Ministry of Education and Research (BMBF) and the Chinese Academy of Sciences (CAS). In this paper, a description of the DSS, the development of its components, and results of its application are presented. The system integrates in-situ measurements, process-based models, and a database management system. Numerical models for the simulation of flow, waves, sediment transport and morphodynamics covering the entire Bohai Sea are set up based on the Delft3D modelling suite (Deltares). Calibration and validation of the models were realized based on the measurements of moored Acoustic Doppler Current Profilers (ADCP) and High Frequency (HF) radars. In order to enable cost-effective and scalable applications, a database management system was developed. It enhances information processing, data evaluation, and supports the generation of data products. Results of the application of the DSS to the management of coastal protection, coastal cage aquaculture and harbors are presented here. Model simulations covering the most severe storms observed during the last decades were carried out leading to an improved understanding of hydrodynamics and morphodynamics. Results helped in the identification of coastal stretches subjected to higher levels of energy and improved support for coastal protection measures.

Keywords: coastal protection, decision support system, in-situ measurements, numerical modelling

Procedia PDF Downloads 194

Authors: Marpaleni

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The intergovernmental Panel on Climate Change (IPCC) declared in 2007 that global warming and climate change are not just a series of events caused by nature, but rather caused by human behaviour. Thus, to reduce the impact of human activities on climate change it is required to have information about how people respond to the environmental issues and what constraints they face. However, information on these and other phenomena remains largely missing, or not fully integrated within the existing data systems. The proposed study is aimed at filling the gap in this knowledge by focusing on Environmentally Friendly Behaviour (EFB) of the people of Indonesia, by taking the province of South Sumatera as a case of study. EFB is defined as any activity in which people engage to improve the conditions of the natural resources and/or to diminish the impact of their behaviour on the environment. This activity is measured in terms of consumption in five areas at the household level, namely housing, energy, water usage, recycling and transportation. By adopting the Indonesia’s Environmentally Friendly Behaviour conducted by Statistics Indonesia in 2013, this study aims to precisely identify one’s orientation towards EFB based on socio demographic characteristics such as: age, income, occupation, location, education, gender and family size. The results of this research will be useful to precisely identify what support people require to strengthen their EFB, to help identify specific constraints that different actors and groups face and to uncover a more holistic understanding of EFB in relation to particular demographic and socio-economics contexts. As the empirical data are examined from the national data sample framework, which will continue to be collected, it can be used to forecast and monitor the future of EFB.

Keywords: environmentally friendly behavior, demographic, South Sumatera, Indonesia

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Authors: Sharvare Palwai, Padmaja Guggilla

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Smart materials, also called as responsive materials, undergo reversible physical or chemical changes in their properties as a consequence of small environmental variations. They can respond to a single or multiple stimuli such as stress, temperature, moist, electric or magnetic fields, light, or chemical compounds. Hence smart materials are the basis of many applications, including biosensors and transducers, particularly electroactive polymers. As the polymers exhibit good flexibility, high transparency, easy processing, and low cost, they would be promising for the sensor material. Polyvinylidene Fluoride (PVDF), being a ferroelectric polymer, exhibits piezoelectric and pyro electric properties. Pyroelectric materials convert heat directly into electricity, while piezoelectric materials convert mechanical energy into electricity. These characteristics of PVDF make it useful in biosensor devices and batteries. However, the influence of nanoparticle fillers such as Lithium Tantalate (LiTaO₃/LT), Potassium Niobate (KNbO₃/PN), and Zinc Titanate (ZnTiO₃/ZT) in polymer films will be studied comprehensively. Developing advanced and cost-effective biosensors is pivotal to foresee the fullest potential of polymer based wireless sensor networks, which will further enable new types of self-powered applications. Finally, nanocomposites films with best set of properties; the sensory elements will be designed and tested for their performance as electric generators under laboratory conditions. By characterizing the materials for their optical properties and investigate the effects of doping on the bandgap energies, the science in the next-generation biosensor technologies can be advanced.

Keywords: polyvinylidene fluoride, PVDF, lithium tantalate, potassium niobate, zinc titanate

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Authors: Vivek Upadhayay, Siddharth Deshmukh

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In recent years utilization of renewable energy sources has increased majorly because of the increase in global warming concerns. Organization these days are generally operated by Micro grid or smart grid on a small level. Power optimization and optimal load tripping is possible in a smart grid based industry. In any plant or industry loads can be divided into different categories based on their importance to the plant and power requirement pattern in the working days. Coming up with an idea to divide loads in different such categories and providing different power management algorithm to each category of load can reduce the power cost and can come handy in balancing stability and reliability of power. An objective function is defined which is subjected to a variable that we are supposed to minimize. Constraint equations are formed taking difference between the power usages pattern of present day and same day of previous week. By considering the objectives of minimal load tripping and optimal power distribution the proposed problem formulation is a multi-object optimization problem. Through normalization of each objective function, the multi-objective optimization is transformed to single-objective optimization. As a result we are getting the optimized values of power required to each load for present day by use of the past values of the required power for the same day of last week. It is quite a demand response scheduling of power. These minimized values then will be distributed to each load through an algorithm used to optimize the power distribution at a greater depth. In case of power storage exceeding the power requirement, profit can be made by selling exceeding power to the main grid.

Keywords: power flow optimization, power trading enhancement, smart grid, multi-object optimization

Procedia PDF Downloads 522

Authors: K. M. Yoo, M. H. Kang

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Conventional commercial wind turbine design software is limited to large wind turbines due to not incorporating with low Reynold’s Number aerodynamic characteristics typically for small wind turbines. To extract maximum annual energy product from an intermediately designed small wind turbine associated with measured wind data, numerous simulation is highly recommended to have a best fitting planform design with proper airfoil configuration. Since depending upon wind distribution with average wind speed, an optimal wind turbine planform design changes accordingly. It is theoretically not difficult, though, it is very inconveniently time-consuming design procedure to finalize conceptual layout of a desired small wind turbine. Thus, to help simulations easier and faster, a GUI software is developed to conveniently iterate and change airfoil types, wind data, and geometric blade data as well. With magnetic generator torque curve, peak power tracking simulation is also available to better match with the magnetic generator. Small wind turbine often lacks starting torque due to blade optimization. Thus this simulation is also embedded along with yaw design. This software provides various blade cross section details at user’s design convenience such as skin thickness control with fiber direction option, spar shape, and their material properties. Since small wind turbine is under international safety regulations with fatigue damage during normal operations and safety load analyses with ultimate excessive loads, load analyses are provided with each category mandated in the safety regulations.

Keywords: GUI software, Low Reynold’s number aerodynamics, peak power tracking, safety regulations, wind turbine performance optimization

Procedia PDF Downloads 302

Authors: Aysegul Evren Yapicioglu

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The social roles and responsibilities expected from citizens are increasing due to changing global living conditions. Science education is expected to prepare conscious and sensitive students. Because today’s students are the adults of future. Precondition of this task is Teacher Education. In the past decade, one of the most important research field is socioscientific issues. This study deals with advantages and disadvantages of socioscientific issue based instruction in science classroom according to pre-service science teachers’ views. A case study approach that is one of the qualitative research design was used to explore their views. Fourteen pre-service science teachers participated to instruction process. Dolphinariums, Kyoto Protocol, genetically modified organisms, recyclable black bags’ benefits and damages, genetic tests, alternative energy sources and organ donation are examples of socioscientific issues, which were taught through activities in a special teaching course. Diaries and focus group interview were used as data collection tools. As a result of the study, the advantages of socioscientific issue based instruction in science classroom comprise of six sub-categories which are multi-skilling, social awareness development of thinking, meaningful learning, character and professional development, contribution of scientific literacy whereas disadvantages of this instruction process are challenges teachers and students, limitations of teaching and learning process in pre-service science teachers’ perspectives. Finally, this study contributes to science teachers and researchers to overcome disadvantages and benefit from the advantage of socioscientific issue based instruction in science classroom.

Keywords: science education, socioscientific issues, socioscientific issue based instruction, pre-service science teacher

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Authors: Sadhana Sharma, P. K. Nema, Siddhartha Singha

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Paneer or Indian cottage cheese is an acid and heat coagulated milk product, highly perishable because of high moisture (58-60 %). Typically paneer is marble to light creamy white in appearance. A good paneer should have cohesive body with slight sponginess or springiness. The texture must be smooth and velvety with close-knit compactness. It should have pleasing mild acidic, slightly sweet and nutty flavour. Consumers today demand simple to prepare, convenient, healthy and natural foods. Dehydrated paneer finds numerous ways to be used. It can be used in curry preparation similar to paneer-in-curry, a delicacy in Indian cuisine. It may be added to granola/ trail mix yielding a high energy snack. If grounded to a powder, it may be used as a cheesy spice mix or used as popcorn seasoning. Dried paneer powder may be added to pizza dough or to a white sauce to turn it into a paneer sauce. Drying of such food hydrogels by conventional methods is associated with several undesirable characteristics including case hardening, longer drying time, poor rehydration ability and fat loss during drying. The present study focuses on developing cost-effective protocol for freeze-drying of paneer. The dehydrated product would be shelf-stable and can be rehydrated to its original state having flavor and texture comparable to the fresh form. Moreover, the final product after rehydration would be more fresh and softer than its frozen counterparts. The developed product would be shelf-stable at room temperature without any addition of preservatives.

Keywords: color, freeze-drying, paneer, texture

Procedia PDF Downloads 158