On use of remotely sensed land surface data from satellite for preliminary wind resource assessment

Wind resource assessment is an essential per-requisite for economic harnessing of wind energy. Although collection of wind data at a site over a period of time is necessary, localisation of such a site in itself is a task considering the vast land surface having different terrain features. This calls for a preliminary assessment of wind velocity based on meteorological information, land surface conditions and terrain features. Topographic maps and agricultural and forest data are normally used for understanding the land surface. This brief report discusses the possibility of using satellite imagery as a supplementary tool to assess the land surface. Possible uses of satellite data products in land cover and terrain analysis, underlying advantages, image interpretation methodology and expected refinements in satellite data collection and analysis in future, of relevance to wind resource assessment, are briefly outlined

A report on visit to windmill test station in Europe

This report prepared by three NAL scientists covers visits of five test -stations for wind machines located in Denmark, Federal Republic of Germany, the Netherlands and the U.K. The objective of this visit was to make an assessment of the need and the practices followed at these places in regards to testing and certification of wind machines and associated R&D. This was with a view to prepare a revised project proposal for a Test Station for windmills in India under the Wind Energy Centre at NAL for consideration of DANIDA who had also sponsored this visit. This report provides essential information regarding organisation, nature of activities, manpower and assessment of their experience which might be of relevance in our context. The observations were discussed with the scientists from Riso national Laboratory, Denmark, and also with DANIDA officials at the conclusion of the visit. The visit lasted 12 days between Dec.4-15,1989

Photophysical properties of the fullerenes, C60 and C70

Photophysical properties of the singlet and triplet states of the fullerenes, C60 and C70, have been investigated in toluene, benzene, hexane and ethanol solutions by pico- and nano-second laser flash photolysis techniques. Lifetimes, extinction coefficients, quantum efficiencies of the formation of the excited states and such properties have been determined. True triplet�triplet absorption spectra of C60 and C70 are reported. C60, unlike C70, is found to undergo photoionization in ethanol solution giving solvated electrons

Dynamics of charge transfer in the excited amine complexes of the fullerenes C60 and C70.: A picosecond laser flash photolysis study

In benzene solution, C60 and C70 interact weakly in the ground state with amines having favourable oxidation potentials. Picosecond time-resolved absorption measurements show that on photoexcilation, the weak complexes undergo charge separation to produce ion pairs which in turn undergo fast geminate recombination either to produce the triplet state of the fullerenes or give back the ground slate of the complex, depending on the oxidation potential of the amine. Free-ion yield is generally negligible