Multi-response optimization in machining: exploration of TOPSIS and Deng’s similarity based approach

Machining deals with removal of unwanted material from the work piece in the form of chips in order to get required dimension. Consumption of energy, wastage of material, requirement of skilled person etc. make the process expensive. Hence, machining industries have to face the inevitable challenge to reduce cost as well as to machine material within the tolerance limit which can be accepted by the customers. The output characteristics like Material Removal Rate (MRR), surface roughness, tool wear, tool life, cutting temperature, cutting force etc. are greatly influenced by the input cutting parameters like speed, feed rate, depth of cut etc. Therefore, selection of cutting parameter plays an important role for a sound production. Optimization techniques are quite helpful for selection of appropriate cutting parameters through offline check. The industries have to concern about a number of performance characteristics simultaneously because focus on a single objective may appear as loss for rest of the objectives, and, hence, multi-objective optimization techniques may be suitable. In the present work, turning operation of aluminum was carried out using a HSS tool on a lathe machine. Cutting parameters: speed, feed rate, and depth of cut was varied at five different levels; Taguchi method was employed for designing a L25 orthogonal array. The output performances viz. MRR, surface roughness, cutting temperature, and cutting forces were recorded for each run. Deng’s similarity based method and TOPSIS (integrated with Taguchi method) were explored for determining appropriate process environment (parameter setting) for simultaneous optimization of multiple process-performance-yields

Teaching of Critical Analysis of Drug Advertisements to Medical Students

Background: Medical practitioners utilize drug promotional materials from pharmaceutical companies as a major source of information especially in developing countries. These promotional materials can be highly informative as long as they are critically appraised but when they are accepted without question, they lead to irrational prescribing. Aim: To sensitize the students regarding WHO criteria for medicinal drug promotion and to determine the impact of teaching critical appraisal of medicinal drug promotion to medical students. Design: The medical students of second year were given a pre test questionnaire to identify the violations in generic labeling, pharmacological information, claims, relevance and references cited in the drug advertisements. Later they were sensitized about the WHO criteria for medicinal drug promotion and how to critically appraise a drug advertisement. This was followed by a post test questionnaire with the same drug advertisement. Result: The number of students answering the post test correctly was significantly (p<0.05) more than that of pre test. Conclusion: Education of medical students regarding critical analysis of drug advertisements should be a part of the medical curriculum

Study of electronic properties of III-V semiconductors and semiconductor-superlattices

We have studied different methods for calculating band structures of solids and their density of states which can predict the electronic properties of solids accurately. Especially, computational methods like tight binding approximation and pseudo potential method have been studied and applied to find the band structures and density of states of semiconductors and its superlattices. The project work is divided into two parts. In first part, pseudo potential method has been used to solve computationally by MATLAB, the energy Eigen values of III-V semiconductors like GaAs and AlAs and IV semiconductor i.e. Ge and get a graphical representation of their band structures. In second part, TB-LMTO program which uses tight binding method has been applied to find the band structures and density of states of GaAs and AlAs semiconductors and their superlattices (GaAs/AlAs). A comparison of conducting behaviour of these materials is made finally

Renormalization Group Equation and QCD Coupling Constant in the Presence of SU(3) Chromo-Electric Field

We solve renormalization group equation in QCD in the presence of SU(3) constant chromo-electric field E^a with arbitrary color index a=1,2,...8 and find that the QCD coupling constant \alpha_s depends on two independent casimir/gauge invariants C_1=[E^aE^a] and C_2=[d_{abc}E^aE^bE^c]^2 instead of one gauge invariant C_1=[E^aE^a]. The \beta function is derived from the one-loop effective action. This coupling constant may be useful to study hadron formation from color flux tubes/strings at high energy colliders and to study quark-gluon plasma formation at RHIC and LHC.Comment: 13 pages latex, 4 eps figs, Eur. Phys. J.

Evolution of Primordial Black Hole Mass Spectrum in Brans-Dicke Theory

We investigate the evolution of primordial black hole mass spectrum by including both accretion of radiation and Hawking evaporation within Brans-Dicke cosmology in radiation, matter and vacuum-dominated eras. We also consider the effect of evaporation of primordial black holes on the expansion dynamics of the universe. The analytic solutions describing the energy density of the black holes in equilibrium with radiation are presented. We demonstrate that these solutions act as attractors for the system ensuring stability for both linear and nonlinear situations. We show, however, that inclusion of accretion of radiation delays the onset of this equilibrium in all radiation, matter and vacuum-dominated eras.Comment: 18 pages, one figur