The design, development, and manufacture of large wood/composite wind turbine rotors

Discusses a study conducted to determine the best development path for large wind turbine rotor design. Shape and number of blades, degrees of freedom allowed, and control strategy are considered. Manufacture and costs are also discussed. Two-bladed, stall-regulated, teetered rotors are more cost effective than three-bladed rotors. Single-bladed rotors can be even more cost-effective. No new manufacturing techniques are required. The most cost-effective rotor includes a hub constructed in wood/composite materials, bonded to the blades. There is strong incentive for the blade manufacturer to supply the complete rotor. (from author's abstract)

Vocational education for the development of knowledge system in fisheries sector

The paper aims to give the concept and functional approach of knowledge system with reference to the fisheries sector. The background and strategies to develop knowledge workers by translating the concept of knowledge system are presented. The job opportunities given in the paper strengthen the need of the development of knowledge workers through vocational education and training. The Vocational Education Programme in the backdrop can be effective both in the formal system of education through different models suggested and through the non-formal system. The modular courses varying from 50 hours and 2-3 weeks to 6 months or one year can be introduced in the formal system as pre-vocational modules (50-h duration) in IX-X classes in vocational institutions, and the non-governmental organizations/Krishi Vigyan Kendras/Indian Council of Agricultural Research may offer occupation-based modules (2-3 weeks to 6 months). The strategic approach for the development of knowledge system highlighting various issues is also suggested.

Institutional support for freshwater aquaculture development: a study of Mirzapur district of Uttar Pradesh, India

The aquaculture sector has been playing an increasingly dominating role in Indian fisheries scenario since the last two and half decades. Introduction of induced breeding and composite fish culture (CFC) technologies has changed the freshwater aquaculture sector in India. Institutional support has been one of the most crucial aspects in all fisheries development programs, more so in the Indian context where most of fish farmers are socially and economically weak. The innovation of CFC technology in freshwater aquaculture sector in the early seventies generated the need for adequate and effective institutional support to farmers. Under the freshwater aquaculture development program, the Fish Farmers Development Agencies (FFDA) have been established at district level to provide technical and extension support to the farming community besides arranging ponds on lease and supply of seeds. In addition to above, FFDAs are also expected to arrange loans from banks and provide subsidies. Thus, FFDAs are meant to provide institutional support to fish farming community in the country. In view of the above, an effort was made to study the adequacy and effectiveness of institutional support provided by the FFDA, Mirzapur for the development of aquaculture in Mirzapur district of Uttar Pradesh {U.P.), India. Study reveals that leasing of ponds for fish farming has been favourable to economically weaker sections of societies while bank loan accessibility is more for those having relatively higher economic status. Though the FFDA, Mirzapur performed well in providing training to potential fish farmers and creating awareness about fish farming, its effectiveness could not be equally seen in seed supply.

Development and evaluation of an alternative method for processing elastic-lidar return signals

A method for interpreting elastic-lidar return signals in heavily-polluted atmospheres is presented. It is based on an equation derived directly from the classic lidar equation, which highlights gradients of the atmospheric backscattering properties along the laser optical path. The method is evaluated by comparing its results with those obtained with the differential absorption technique. The results were obtained from locating and ranging measurements in pollutant plumes and contaminated environments around central México. © World Scientific Publishing Company.

Design, development, and evaluation of a simple blackbody radiative source

This paper presents a simple design and the testing of a blackbody prototype. The physical properties and geometry of the cavity produce a radiator or blackbody with an emissivity greater than 0.99. The prototype has the advantages of having a traditional spherical cavity made of alumina refractory cement and a radiative emission very close to that of an ideal blackbody. The prototype can be used as a calibration standard for other radiation measuring instruments or sensors. Experimental measurements of radiant flux of the prototype measured with a calibrated infrared radiometer and a wide spectrum radiometer are also presented. The prototype is easy to construct and the material required are available to most research centers, laboratories, industries, and universities. © 2010 American Institute of Physics.