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  • Author or Editor: S. Ramachandran x
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Tricalcium silicate characteristically exhibits the most intense reversible transition at a temperature of about 915‡. The intensity of this effect can be used to estimate the amount of C3S in mixtures and to calculate the degree of hydration of C3S. Low sensitivity forδT up to 800‡ and higher sensitivity between 800‡ and 1000‡ enable estimation of both Ca(OH)2 and C3S. Interference effects at higher temperatures owing to decarbonation, recrystallization toΒ-wollastonite, and dehydration of the calcium silicate hydrate can be overcome by heating to 1000‡, cooling to 800‡, and reheating. A determination of the degree of hydration of C3S obtained at different periods by DTA correlates well with that using the X-ray method.

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Abstract  

To delineate the intellectual structure of Antarctic science, the research outputs on Antarctic science have been analyzed for a period of 25 years (1980–2004) through a set of scientometrics and network analysis techniques. The study is based on 10,942 records (research articles, letters, reviews, etc.), published in 961 journals/documents, and retrieved from the Science Citation Index (SCI) database. Over the years interest in Antarctic science has increased, as is evident from the growing number of ratified countries and research stations. During the period under study, the productivity has increased 3-times and there is a 13-fold increase in collaborative articles. Attempt has been made to identify important players like scientists, organizations and countries working in the field and to identify frontier areas of research that is being conducted in this continent. The highest 41% scientific output is contributed by the USA and the UK, followed by Australia and Germany. British Antarctic Survey (BAS), UK and Alfred Wegener Institute of Polar & Marine Research, Germany are the most productive institutes in Antarctic science. Maximum number of research articles on Antarctic science, have been published in the journal Polar Biology, indicating substantial work being done on the biology of this continent. The journals — Nature and Science — are the highly-cited journals in Antarctic science. The paper written by J. C. Farman et al., published in Nature in 1985, reporting depletion of ozone layer, is the most-cited article. Semantic relationships between cited documents were measured through co-citation analysis. J. C. Farman and S. Solomon are co-cited most frequently.

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Summary In this paper attempt has been made to study the engineering research scenario in ocean sector across the countries - globally. To understand the research dynamics, the articles appeared in Science Citation Index (SCI) database under Ocean Engineering category in the year 2000 were analyzed to visualize the structure of the field. USA and UK are the major producers - 62% of the total output contributed by them. The cooperation linkages between engineers, organizations, countries and journals were mapped. The causal linkages between the productivity function and the socio-economic imperatives of the production units were studied. 62% output in this sector goes to USA & UK. They are also toppers in collaboration centrality list. National Oceanic Atmospheric Administration (NOAA), USA; National Aeronautics and Space Administration (NASA), USA; National Institute of Oceanography (NIO), India are the most productive institutions. GDP explains only 36% of variance in productivity (R2 = 0.36). M Longuethiggins and CC Mei are the most cited authors in the field. Co-citation maps of cited authors and cited journals throw light on the semantic structure of the field. Studies in wave mechanics and modeling of waves are the most important areas of research in Ocean Technology.

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