Delhi Technological University

About: Delhi Technological University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 4427 authors who have published 6761 publications receiving 71035 citations. The organization is also known as: Delhi College of Engineering & DTU.

Analyzing challenges for sustainable supply chain of electric vehicle batteries using a hybrid approach of Delphi and Best-Worst Method

Abstract: Due to global warming and fast depletion of fossil fuels, the option of battery-operated electric vehicles (EVs) has emerged as one of the most popular alternatives for sustainable transport. In the present study, India is considered as a case country to explore the challenges in sustainable supply chain of electric vehicle batteries. India, being the second most populated country after China and having limited reserves of fossil fuels, has great potential to excel in electric vehicle supply chains. In addition, growth of electric vehicle markets in India is in the emerging phase. With increasing demand for EVs, the industry is facing many challenges for sustainable supply chain of electric vehicle batteries. The lithium-ion battery is a major component of electric vehicles. Many challenges for sustainability of electric vehicle battery supply chains have been extracted through literature review and discussions with industry experts. These challenges may be categorized as operational, technological, economic, environmental and social. Delphi technique is utilized to finalize major challenges for analysis. For further prioritization of these challenges, Best-Worst Method (BWM) is used. Finally, findings of the BWM are validated through an empirical study by collecting responses from 87 respondents. It is observed that ineffective recycling and reuse of batteries, disposal of batteries, and insufficient charging infrastructure are the three most important challenges in EV battery supply chain in India. The findings may be equally relevant in many developing countries having similar technological and infrastructure constraints. It will help policymakers in developing strategies for sustainable transport systems in developing countries.

Fragment based group QSAR and molecular dynamics mechanistic studies on arylthioindole derivatives targeting the α-β interfacial site of human tubulin

Abstract: A number of microtubule disassembly blocking agents and inhibitors of tubulin polymerization have been elements of great interest in anti-cancer therapy, some of them even entering into the clinical trials. One such class of tubulin assembly inhibitors is of arylthioindole derivatives which results in effective microtubule disorganization responsible for cell apoptosis by interacting with the colchicine binding site of the β-unit of tubulin close to the interface with the α unit. We modelled the human tubulin β unit (chain D) protein and performed docking studies to elucidate the detailed binding mode of actions associated with their inhibition. The activity enhancing structural aspects were evaluated using a fragment-based Group QSAR (G-QSAR) model and was validated statistically to determine its robustness. A combinatorial library was generated keeping the arylthioindole moiety as the template and their activities were predicted. The G-QSAR model obtained was statistically significant with r2 value of 0.85, cross validated correlation coefficient q2 value of 0.71 and pred_r2 (r2 value for test set) value of 0.89. A high F test value of 65.76 suggests robustness of the model. Screening of the combinatorial library on the basis of predicted activity values yielded two compounds HPI (predicted pIC50 = 6.042) and MSI (predicted pIC50 = 6.001) whose interactions with the D chain of modelled human tubulin protein were evaluated in detail. A toxicity evaluation resulted in MSI being less toxic in comparison to HPI. The study provides an insight into the crucial structural requirements and the necessary chemical substitutions required for the arylthioindole moiety to exhibit enhanced inhibitory activity against human tubulin. The two reported compounds HPI and MSI showed promising anti cancer activities and thus can be considered as potent leads against cancer. The toxicity evaluation of these compounds suggests that MSI is a promising therapeutic candidate. This study provided another stepping stone in the direction of evaluating tubulin inhibition and microtubule disassembly degeneration as viable targets for development of novel therapeutics against cancer.

Thermodynamic analysis of R422 series refrigerants as alternative refrigerants to HCFC22 in a vapour compression refrigeration system

Abstract: In the present study, the first and second law analysis of R422 series refrigerants (R422A, R422B, R422C and R422D) is presented as an alternative to HCFC22. A computational model, developed in engineering equation solver software, is employed for comparing the performance of these refrigerants in vapour compression refrigeration cycle. The thermodynamic properties of the R422 series refrigerants are computed using Refprop version 7.0. The parameters computed are volumetric cooling capacity (VCC), compressor discharge temperature, coefficient of performance (COP), exergetic efficiency and efficiency defects in system components. The results indicate that VCC, COP and exergetic efficiency for HCFC22 are higher in comparison with R422A, R422B, R422C and R422D. The efficiency defects in the condenser are largest followed by throttle valve, compressor and evaporator. Thus, the design improvement of condenser is of utmost importance to reduce the overall irreversibility and improve the system performance. Copyright © 2009 John Wiley & Sons, Ltd.

A New Approximate Closed-Form Distribution and Performance Analysis of a Composite Weibull/Log-Normal Fading Channel

Abstract: The presence of both the fading and shadowing effects (also called composite multipath/shadowed fading) is often encountered in a realistic radio propagation scenario, thus, making it necessary to consider the simultaneous effect of fading and shadowing on the received signal. The multipath effect is captured using models such as Rician, Nakagami-m, Weibull distribution and shadowing effect is modeled using Log-normal distribution. In this paper we present the closed-form expression of composite (Weibull/log-normal shadowed) fading using the efficient tool proposed by Holtzman. Using this result, the closed-form expression of combined (time-shared) shadowed/unshadowed fading is presented. The performance measures of fading communication systems such as probability density function of signal to noise ratio, amount of fading, outage probability (Pout) and channel capacity are analyzed and expressed in closed form.