Jadavpur University

About: Jadavpur University is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Population & Fuzzy logic. The organization has 10856 authors who have published 27678 publications receiving 422069 citations. The organization is also known as: JU & Jadabpur University.

Application of PCA-based hybrid Taguchi method for correlated multicriteria optimization of submerged arc weld: a case study

Abstract: In the present work, an attempt has been made to solve the correlated multiple criteria optimization problem of submerged arc welding. The target was to search an optimal process environment, capable of producing desired bead geometry parameters of the weldment. Four correlated features of bead geometry: depth of penetration, reinforcement, bead width, and percentage dilution have been selected in the study. The process environment has been assumed consisting of four variables like voltage (OCV), wire feed rate, traverse speed, and electrode stick-out. Multiple correlated responses have been converted into independent quality indices called principal components. Principal component analysis (PCA) has been adapted to covert multiple objectives of the optimization problem into a single objective function. This single objective function has been denoted as composite principal component. Taguchi’s robust optimization technique has been applied to determine the optimal setting, which can maximize the composite principal component. Result of this aforesaid optimization technique has been compared to that of grey-Taguchi technique; another approach which is widely used for solving multicriteria optimization problems. A confirmatory test showed satisfactory result. This concludes application feasibility of PCA-based hybrid Taguchi method for parametric optimization of SA weld.

Augmentation of Heat Transfer by Creation of Streamwise Longitudinal Vortices Using Vortex Generators

Abstract: This paper summarizes the current state of the art related to improvement of the heat exchanger surfaces using streamwise longitudinal vortices Primarily, the improvements related to fin-tube cross-flow heat exchangers and the plate-fin heat exchangers have been addressed Protrusions in certain forms, such as delta wings or winglet pairs, act as vortex generators, which can enhance the rate of heat transfer from the heat-exchanger surfaces that may be flat or louvered The strategically placed vortex generators create longitudinal vortices, which disrupt the growth of the thermal boundary layer, promote mixing between fluid layers, and hence lead to augmentation in heat transfer The flow fields are dominated by swirling motion associated with modest pressure penalty Heat transfer is augmented substantially for all the proposed configurations of the longitudinal vortex generators, such as delta wings, rectangular winglet pairs, and delta winglet pairs, with varying degree of pressure penalty Both comp

Kinetics of adsorption of cationic surfactants at silica-water interface

Abstract: The kinetics of adsorption of cationic surfactants (CTAB, MTAB and DTAB) at silica surface has been studied at various values of bulk surfactant concentration (Ct 2), pH, ionic strength, and temperature and in presence of different electrolytes and urea. The adsorption process has been found to follow a two-step first-order kinetic rate equation with two different rate constants k1 and k2. From the variation of k1 and k2 with temperature, values of energies of activation Ea1 and Ea2 for both the kinetic steps have been evaluated. The corresponding values of enthalpies of activation (DeltaH 1# and DeltaH 2#), entropies of activation (DeltaS 1# and DeltaS 2#) have been evaluated using Eyring's equation for absolute reaction rate. It has been found that for both the kinetic steps, DeltaH 1# 1# and DeltaH 2# 2#, which means that activation reaction is largely entropy controlled. Again, for both kinetic steps, DeltaH# varies linearly with TavDeltaS#, and DeltaG 1# and DeltaG 2# vary between 70 and 88 kJ/mole of surfactant, respectively. Thus there is a entropy-enthalpy compensation effect in the adsorption process. Copyright 1998 Academic Press.

Quality of Service (QoS) Provisions in Wireless Sensor Networks and Related Challenges

Abstract: Wireless sensor networks (WSNs) are required to provide different levels of Quality of Services (QoS) based on the type of applications. Providing QoS support in wireless sensor networks is an emerging area of research. Due to resource constraints like processing power, memory, bandwidth and power sources in sensor networks, QoS support in WSNs is a challenging task. In this paper, we discuss the QoS requirements in WSNs and present a survey of some of the QoS aware routing techniques in WSNs. We also explore the middleware approaches for QoS support in WSNs and finally, highlight some open issues and future direction of research for providing QoS in WSNs.