Indian Institute of Technology Bombay

About: Indian Institute of Technology Bombay is a education organization based out in Mumbai, India. It is known for research contribution in the topics: Population & Thin film. The organization has 16756 authors who have published 33588 publications receiving 570559 citations.

Giant inverse magnetocaloric effect near room temperature in Co substituted NiMnSb Heusler alloys

Abstract: The effect of Co on the structural, magnetic and magnetocaloric effect (MCE) of Ni50−xCoxMn38Sb12 (x = 0, 2, 3, 4, 5) Heusler alloys was studied. Using x-ray diffraction, we show the evolution of the martensitic phase from the austenite phase. The martensitic transition temperature is found to decrease monotonically with Co concentration. Remarkable enhancement of MCE is observed near room temperature upon Co substitution. The maximum magnetic entropy change of 34Jkg −1 K −1 was achieved for x = 5 at 262K in a field of 50kOe and a value of 29Jkg −1 K −1 was found near room temperature. The significant increase in the magnetization with large magneto-structural coupling associated with the reverse martensitic transition is responsible for the giant MCE in these compounds. (Some figures in this article are in colour only in the electronic version)

Impacts of urbanization on Indian summer monsoon rainfall extremes

Abstract: Urban areas have different climatology with respect to their rural surroundings. Though urbanization is a worldwide phenomenon, it is especially prevalent in India, where urban areas have experienced an unprecedented rate of growth over the last 30 years. Here we take up an observational study to understand the influence of urbanization on the characteristics of precipitation (specifically extremes) in India. We identify 42 urban regions and compare their extreme rainfall characteristics with those of surrounding rural areas. We observe that, on an overall scale, the urban signatures on extreme rainfall are not prominently and consistently visible, but they are spatially nonuniform. Zonal analysis reveals significant impacts of urbanization on extreme rainfall in central and western regions of India. An additional examination, to understand the influences of urbanization on heavy rainfall climatology, is carried with station level data using a statistical method, quantile regression. This is performed for the most populated city of India, Mumbai, in pair with a nearby nonurban area, Alibaug; both having similar geographic location. The derived extreme rainfall regression quantiles reveal the sensitivity of extreme rainfall events to the increased urbanization. Overall the study identifies the climatological zones in India, where increased urbanization affects regional rainfall pattern and extremes, with a detailed case study of Mumbai. This also calls attention to the need of further experimental investigation, for the identification of the key climatological processes, in different regions of India, affected by increased urbanization.

Intelligent natural language query processor

Abstract: A description is given of the implementation of a natural language query (NLQ) processor based on the pattern matching paradigm (PMP) in standard Prolog on an IBM-PC/XT. In the light of this experiment, certain issues encountered in natural language understanding are discussed. PMP is a simplistic syntactic approach to natural language understanding and works well in limited applications. However, the NLQ presented cannot detect semantic contradictions, as it does not use any data restriction/dependency information to detect semantic errors in conversation. >