This work presents the wire-EDM of WC-Co composite and optimization of process parameters using an integrated technique of response surface methodology (RSM), Vise Kriterijumska Optimizacija ...Kompromisno Resenje (VIKOR) and artificial bee colony (ABC) algorithm to obtain the best set of machinability indicators. Wire feed (WF), servo voltage (SV), pulse off-time (Pon) and pulse on-time (Poff) are the variable process parameters, whereas root mean square roughness (Rq), average surface roughness (Ra) and material removal rate (MRR) are the machinability indicators considered in the present work. A total of twenty nine experiments have been conducted based on Box Behnken design (BBD) technique of response surface methodology. VIKOR has been used for normalization of responses and followed by solving empirical models using ABC algorithm to obtain optimized process parameters setting. WF-12 m/min, SV-65V, Pon-116 µs, Poff-20 µs are the optimum wire-EDM parameters obtained by intelligent RSM-VIKOR-ABC technique that produced best values of Ra-4.51 µm, Rq-5.64 µm, MRR-0.061 mm3 /min simultaneously. The validation test confirmed an improvement up to 15% in the response characteristics which proved the effectiveness of this novel hybrid technique for optimization. The optimum parameter setting is for ready industrial reference to attain best surface quality and process productivity for WC-Co composite machining by wire-EDM.
Shape memory alloys are important biomaterials but difficult-to-machine (DTM). Their machining needs to be done using intelligent techniques to obtain a better machinability. Hybrid optimization is ...one of such techniques which can do modelling and optimization of machining parameters for the best values of machinability indicators. Wire electric discharge machining (WEDM) of shape memory alloy has been found as a prominent alternate to the conventional machining techniques, however it needs the assistance of intelligent techniques to machine such materials to get the optimum values of machinability indicators. In this paper, WEDM of shape memory alloy Ni55.8Ti is reported. WEDM has been done by varying four process parameters i.e. servo voltage SV, pulse-on time Pon, pulse-off time Poff, and wire feed rate WF using Taguchi L16 robust design of experiment technique. A hybrid optimization technique TOPSIS-Fuzzy-PSO has been successfully used to optimize these parameters (SV-50V; Pon-1µs; Poff-17 µs; WF-4 m/min) for the best possible values of material removal rate (MRR)- 0.049 g/min, maximum roughness- 11.45 µm, and recast layer- 22.10 µm simultaneously.
Manufacturing of miniature gears with good accuracy and quality, and at low cost is a challenging task for traditional manufacturing processes. Wire-cut electric discharge machining (WEDM) has the ...capacity to machine any conductive material to fabricate typical shaped products like gears with high level of accuracy and quality. In present research, stainless steel (SS) alloy 316 is used to fabricate miniature gears by WEDM. The experimental array is designed according to Response Surface Methodology (RSM) based central composite face centered (CCFC). Four input parameters namely servo feed (SF), duty factor (DF), servo voltage (SV) and wire feed (WF) with three levels each are used for experimental array to investigate the process performance in terms of cutting rate (CR), and product i.e. gear quality in terms of mean roughness depth (Rz) and dimensional deviation (DD). After WEDM parameter optimization, confirmation experiments are performed at the parametric setting by considering equal importance to all response variables. A very close agreement between the experimental and predicted values have been observed.
The rotor or impeller is a rotational and key part of a pump and compressor. This article presents the detailed development process of a rotor of small size constructed from an EN8 steel cylindrical ...blank using a novel technique based on a computer numerical control engraving milling machine (CNC-EMM) equipped with a 4 mm tungsten carbide end mill cutter. We fabricated a total of twenty-eight stepped rotors following the Box-Behnken Design (BBD) DoE technique at fourteen distinct combinations of CNC-EMM variable parameters, namely rotational speed, feed, and plunge feed. Average roughness '
', an important surface quality indicator, has been considered and presented in this article, as a quality measure for the fabricated rotors. Feed and plunge feed have been identified as the most influencing variable parameters as per an analysis of variance (ANOVA) test. The lowest average roughness value obtained by this process for the rotor blade was 0.11 µm. A micrograph obtained from a field-emission scanning electron microscope (FE-SEM) showed a uniform and accurate tooth profile along with burr formation at corner edges. This study claims to establish engraving milling as a viable alternative to other manufacturing processes used for rotor blades. The findings of this study are useful to scholars, engineers, and researchers who are exploring new ways to fabricate mechanical parts and components.
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The pursuit of energy efficiency in machining processes is a critical aspect of sustainable manufacturing. A significant portion of global energy consumption is by the industrial sector; thus, ...improving the energy efficiency of machining processes can lead to substantial environmental and economic benefits. The present study reviews the recent advancement made for improving the energy efficiency of machining processes. First the energy consumption of the machining processes was explored and then the key areas and developments in their energy consumption modeling were identified. Following this, the review explores various strategies for achieving energy savings in machining. These strategies include energy-efficient machine tools, the accurate modeling of the energy consumption of machining processes, the implementation of optimization techniques and the application of artificial intelligence (AI). Additionally, the review highlights the potential of AI in further reducing energy consumption within machining operations and achieving energy efficiency. A review of these energy-saving strategies in machining processes reveals impressive potential for significant reductions in energy consumption: energy-efficient design can achieve up to a 45% reduction, optimizing cutting parameters may minimize consumption by around 40%, optimizing tool paths can reduce consumption by approximately 50%, optimizing non-cutting energy consumption and sequencing can lead to savings of about 30% and employing AI shows promising energy efficiency improvements of around 20%. Overall, the present review offers valuable insights into recent advancements in making machining processes more energy-efficient. It identifies key areas where significant energy savings can be achieved.
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This paper reports the surface quality of a miniature cylindrical titanium rod/bar (MCTB) turned by the wire electrical discharge turning (WEDT) process using a zinc-coated wire of 250 µm diameter. ...The surface quality was mainly evaluated by considering the very important surface roughness parameters, i.e., the mean roughness depth. A Box-Behnken design (BBD) of the response surface methodology (RSM) based on 17 experimental runs was conducted, where the spark duration "
" was found as the most influential parameter affecting the mean roughness depth "
" of the miniature titanium bar. Further, using the grey relational analysis (GRA) technique of optimization, we obtained the least value of "
" 7.42 µm after machining a miniature cylindrical titanium bar with the optimum combination of WEDT's variable parameters:
-0.9 µs,
-30 V, and DOC-0.35 mm. This optimization led to a 37% reduction in the surface roughness
of the MCTB. The tribological characteristics of this MCTB were also found favorable after conducting a wear test. After completing a comparative study, we can claim that our results are better than those of the past research conducted in this area. The findings of this study are beneficial for the micro-turning of cylindrical bars made from a variety of difficult-to-machine materials.
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Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represents a global crisis. Key to SARS-CoV-2 therapeutic development is unraveling the ...mechanisms that drive high infectivity, broad tissue tropism, and severe pathology. Our 2.85-angstrom cryo-electron microscopy structure of SARS-CoV-2 spike (S) glycoprotein reveals that the receptor binding domains tightly bind the essential free fatty acid linoleic acid (LA) in three composite binding pockets. A similar pocket also appears to be present in the highly pathogenic severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV). LA binding stabilizes a locked S conformation, resulting in reduced angiotensin-converting enzyme 2 (ACE2) interaction in vitro
In human cells, LA supplementation synergizes with the COVID-19 drug remdesivir, suppressing SARS-CoV-2 replication. Our structure directly links LA and S, setting the stage for intervention strategies that target LA binding by SARS-CoV-2.
These days, metal matrix composites (MMCs) are being widely utilized in automotive and aerospace industries as prominent alternatives to traditional materials. Owing to their elevated ...strength-to-weight proportion, exceptional fracture toughness, and lightweight design, they can be used in a variety of applications. MMCs undergo extensive machining while making parts and components out of them. The machining of monolithic materials, such as metals and alloys, is a widely used and established process in different industries, such as the aerospace, bio-medical, and automotive sectors. Because of the properties of the metal matrix and the strong reinforcement, MMCs provide unique challenges. Modern machining processes have been found to be superior in overcoming challenges and achieving improved machinability of MMCs. An overview of MMC machining with modern methods is provided in this article. This article first outlines MMCs and addresses the need for and difficulties associated with their machining. Next, it reviews previous investigations on the machining of MMCs employing modern methods like electrical discharge machining, laser machining, abrasive machining, and hybrid machining. Productivity and surface integrity issues, including delamination and roughness, etc., are discussed. When presenting the review, the benefits and drawbacks of modern processes are also taken into account.
Challenges in developing urban flood resilience in India Gupta, Kapil
Philosophical transactions - Royal Society. Mathematical, Physical and engineering sciences/Philosophical transactions - Royal Society. Mathematical, physical and engineering sciences,
04/2020, Volume:
378, Issue:
2168
Journal Article
Peer reviewed
Open access
This note presents a short commentary on the recurring urban flooding in India and the challenges the country faces in implementing sustainable drainage practices and developing urban flood ...resilience. The major incidences of heavy rainfall and the consequent urban flooding and their causes are briefly described. The recent flood disaster management and mitigation measures carried out by the Central, State and Local Government are highlighted. The flood resilience initiatives and challenges are then discussed. The effects of climate change on increased rainfall in shorter durations are now being felt in many Indian cities. The planners are now taking cognizance of this and future flood resilience measures are being planned to incorporate an integrated approach to stormwater management by recommending best management practices in the stormwater manuals. However, a lot still needs to be done to make the cities in India flood resilient. This article is part of the theme issue 'Urban flood resilience'.
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The engineering projects sector has presented numerous challenges in achieving success. The need arises to understand the reasons for these challenges and determine the best way to address the issues ...and achieve success using the best approach. This study aims to gain a good understanding of the factors impacting project success in the engineering sector. The literature review revealed variables that influence project success. These variables are company culture, effective management, employee engagement, and effective planning. The study presents a statistical analysis of the data. This analysis shows that each independent variable studied has a distinct impact on the dependent variable, project success. The South African engineering projects industry has shown a relationship between identified factors and project success. This study recommends laying a solid foundation to apply and improve the identified factors that have an impact on project success in the industry.
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