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Fuzzy multi-objective optimization model to design a sustainable closed-loop manufacturing system
No full textRepublicans and Democrats practically everywhere have been demonstrating concerns about environmental conservation to achieve sustainable development goals (SDGs) since the turn of the century. To promote fuel (energy) savings and a reduction in the amount of carbon dioxide CO2 emissions in several enterprises, actions have been taken based on the concepts described. This study proposes an environmentally friendly manufacturing system designed to minimize environmental impacts. Specifically, it aims to develop a sustainable manufacturing process that accounts for energy consumption and CO2 emissions from direct and indirect energy sources. A multi-objective mathematical model has been formulated, incorporating financial and environmental constraints, to minimize overall costs, energy consumption, and CO2 emissions within the manufacturing framework. The input model parameters for real-world situations are generally unpredictable, so a fuzzy multi-objective model will be developed as a way to handle it. The validity of the proposed ecological industrial design will be tested using a scenario-based approach. Results demonstrate the high reliability, applicability, and effectiveness of the proposed network when analyzed using the developed techniques.</jats:p
The associations between EFL learners’ L2 class belongingness, emotion regulation strategies, and perceived L2 proficiency in an online learning context
No full textInvestigation of Dielectric Properties of 5CB and Chiral Pyridine Based Liquid Crystal Composites
No full textComprehensive technical and economic evaluations of using second-life batteries as energy storage in off-grid applications: A customized cost analysis
No full textThe widespread use of lithium-ion batteries has raised significant waste management challenges, exacerbated by limited integration into recycling systems. When functional batteries are discarded rather than repurposed, valuable resources are lost. The emerging second-life battery (SLB) market presents a promising solution. However, uncertainties in SLB pricing significantly impact their economic viability and feasibility. Accurate pricing of SLB can mitigate substantial losses faced by electric vehicle (EV) users during battery replacements, addressing a major barrier to wider EV adoption. This study introduces a novel approach by employing a dynamic degradation model to determine the cycle life and optimize the capacity of both new and second-life batteries, while also considering round-trip efficiency. A comprehensive economic evaluation using the Net Present Value (NPV) method incorporates detailed cost factors, including purchase, testing, renovation, transportation, replacement costs (calculated using the Sinking Fund method), recycling revenues, and the often-overlooked opportunity cost. Additionally, government incentives are integrated into the analysis, resulting in a robust mathematical framework for pricing SLB. SLB market price under 0 %, 25 %, and 50 % government incentives are calculated as 88.05 €/kWh, 105.5 €/kWh, and 131.60 €/kWh, respectively, representing 34.1 % to 54.1 % of new battery purchase costs. The OEM ownership model shows that accounting for opportunity costs makes SLB 44.9 % more profitable than new batteries. Additionally, a sensitivity analysis was conducted to examine the impact of testing, renovation, and transportation costs, recycling revenue, new battery purchase cost, and discount rate parameters on the NPV of off-grid SLB applications and SLB market pricing. The analysis reveals that the new battery purchase cost has the greatest influence on SLB pricing, while the impact of other parameters is significantly lower. This study highlights the importance of dynamic modeling and comprehensive economic evaluation, emphasizing the need for tailored analyses for each application. These findings provide valuable insights into realistic SLB pricing, enhancing their market potential and supporting broader EV adoption
Enhancement in the performance of a vanadium-manganese redox flow battery using electrospun carbon metal-based electrode catalysts
No full textThis study investigates the performance of both a vanadium/manganese redox flow battery (V/Mn RFB) and an all-vanadium redox flow battery (VRFB), employing carbon metal fabrics (CMFs) prepared through electrospinning followed by carbonization. Noteworthy advancements are observed in both systems upon coupling CMFs with thermally treated graphite felt (GF) electrodes. Nearly doubled peak power density and 50 % higher capacity utilization over 150 charge/discharge cycles at 75 mA cm−2 are achieved for the V/Mn RFB with the incorporation of CMFs alongside graphite felt as catalysts. The VRFB demonstrates notable enhancements too, achieving approximately 200 cycles at a current density of 80 mA cm−2, with high efficiencies (85 %) and electrolyte utilization (79 %) when CMFs are used in combination with graphite felts. These advancements may facilitate pilot-scale testing and integration of the V/Mn RFB for the employment in the renewable energy storage sector and grid-balancing studies
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No full textAxial Flux Permanent Magnet Motor Design for Lightweight Unmanned Aerial Vehicles
No full textAxial flux permanent magnet (AFPM) motors are a type of electric motor in which the magnetic flux between the stator and rotor flows in the axial direction. These motors show superior performance compared to radial flux permanent magnet (RFPM) motors in industrial applications such as fans, industrial pump systems, and automotive industry, due to their ability to operate at high speeds, high-power density, and low flux path features. Nowadays, unmanned aerial vehicles (UAVs) are used in various fields such as mapping, firefighting, logistics, and military fields. High-efficiency, low-weight, and cost-effective motors have been gaining attraction for UAVs. In this paper, an AFPM is designed to achieve high-power density and efficiency in UAV applications. At the design stage, the essential flowchart and the equations used to calculate the dimensions of the AFPM motor are presented. Based on the presented equations, a three-phase axial flux motor simulation is carried out using the Ansys Electronics Desktop software, with a nominal power of 1 kW and a power density of 2.97 W/g, which can be used between 0-12500 rpm. The proposed design procedure is verified with the simulation results using finite element analysis.</p
Measurement of inclusive and differential cross sections for W+W− production in proton-proton collisions at s=13.6 TeV
No full textMeasurements at s=13.6TeV of the opposite-sign W boson pair production cross section in proton-proton collisions are presented. The data used in this study were collected with the CMS detector at the CERN LHC in 2022, and correspond to an integrated luminosity of 34.8fb−1. Events are selected by requiring one electron and one muon of opposite charge. A maximum likelihood fit is performed on signal- and background-enriched data categories defined by the flavor and charge of the leptons, the number of jets, and number of jets originating from b quarks. The overall sensitivity is significantly better than that of previous results with a similar integrated luminosity. The improvement comes from a more refined control of experimental uncertainties and an improved fit strategy. An inclusive W+W− production cross section of 125.7±5.6 pb is measured, in agreement with standard model predictions. Cross sections are also reported in a fiducial region close to that of the detector acceptance, both inclusively and differentially, as a function of the jet multiplicity in the event. For the first time in proton-proton collisions, WW events with zero, one, and at least two jets are studied simultaneously and compared with recent theoretical predictions
Design of a new modular-isolated-forward-based active snubber cell for power switches
No full textIn this paper, a new modular-isolated-forward-based active snubber cell (SC) for power switches is designed. In the proposed new SC, the zero voltage transition (ZVT) technique is implemented with a forward converter although the current counterparts generally use a flyback converter. In the converter with the new SC, the main switch is turned on with ZVT (full zero voltage switching [ZVS]) and turned off with ZVS, the main diode is turned off with zero current switching (ZCS), the auxiliary switch is turned on with ZCS and turned off with ZVS, and the parasitic capacitor energies are recovered. In addition, thanks to the forward converter, it has been possible to minimize the transformer leakage inductance and greatly reduce the current values of devices in the new SC. The new cell is applied to a single-phase, grid-connected, T-type three-level inverter (T2-3LI) as an example. A detailed steady-state analysis of this inverter was made, and the theoretical analysis was confirmed with measurement results taken from a prototype with 100 kHz and 3.3 kW values. Compared to its hard switching (HS) equivalent, in the converter with soft switching (SS) cell, the total circuit loss was reduced from about 248 W to 86 W, thus achieving an increase in the total efficiency from 92.5% to 97.4%