Browsing by Author "Nijaguna, B.T."

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Generally, coconuts are dehusked manually using either a machete or a spike. These methods require skilled labour and are tiring to use. Attempts made so far in the development of dehusking tools have been only partially successful and not effective in replacing manual methods. The reasons quoted for the failure of these tools include unsatisfactory and incomplete dehusking, breakage of the coconut shell while dehusking, spoilage of useful coir, greater effort needed than manual methods, etc. The present work involved the design, development and testing of a coconut dehusker which overcomes the drawbacks of the previously reported implements. The design and developmental stages called for a closer look at the magnitude and direction of the dehusking forces and their generation mechanisms. Details of a simple, sturdy and efficient nineblade dehusker unit, financially beneficial to labourers and producers, are given here. Comparative assessment of this unit in relation to those reported in the literature is provided. Test results and assessment of the present unit in both laboratory and field conditions are also reported. Safety aspects are incorporated. The unit can dehusk about 250 coconuts per hour compared with about 75 nuts per hour from a skilled worker using the spike method. It can be operated by unskilled labourers. Costbenefit analysis indicates that it should be commerically viable. © 1989.
(Coconut dehusker) Nijaguna, B.T.
1988
Most of the theoretical studies in dropwise condensation have based their analysis on the principle that the heat transfer rate limiting mechanism in dropwise condensation is the conduction of heat through drops. Based on this principle, Fatica and Katz presented shape factor values for droplets and these values have been used by other studies. © 1974 Martinus Nijhoff, The Hague.
(Martinus Nijhoff, The Hague/Kluwer Academic Publishers, Drop Nusselt numbers in dropwise condensation) Nijaguna, B.T.
1974
SOLAR INSOLATION AT SURATHKAL - WEST COAST OF INDIA.
(1986) Nijaguna, B.T.
In an attempt to obtain the applicable correlation for the estimation of solar intensity at Surathkal, the number of bright sunshine hours and actual solar insolation were monitored. Regression analysis of the measured data when fitted by a least squares technique resulted in constants in an Armstrong-Page type correlation on a monthly, seasonal and annual basis. The obtained correlations are least erroneous when compared with the actual measured data and are also more appropriate compared to estimates obtained from formulae reported by other studies.
SOLAR INSOLATION AT SURATHKAL - WEST COAST OF INDIA.
(Pergamon Press, 1986) Nijaguna, B.T.
[No abstract available]
The major domestic energy needs of people in the under-developed and developing countries are met by burning wood in cook stoves. The quest for energy conservation and its efficient use has motivated researchers the world over to look for improvements in wood burning cook stoves. Even a marginal increase in efficiency can contribute considerably to a total saving in energy consumption and therefore conservation. Analysis of cooking using wood shows that better energy efficiency can be achieved by complete and controlled combustion of wood, maximum energy transfer to food cooked and reducing the energy losses. The various component design features that contribute to better utilisation of wood energy are discussed. These can be of use in emerging designs, or in the modifications to the existing designs. In addition to dealing with the sizing factors, the rating or performance testing of wood stoves is detailed, thus providing a basis for comparison of different stoves. Operational guidelines that contribute to increased efficiency during cooking are provided.
(Wood burning cook stoves) Nijaguna, B.T.; Uppin, S.B.
1989
The overall performance of a fin and tube type solar flat-plate collector depends mainly on a) meteorological parameters, b) operating parameters, and c) design parameters. The total system cost using solar flat-plate collectors is mainly the initial cost of the collector. In this study, a design methodology based on cost optimization is presented and the cost effective energy equation is obtained. The results obtained show that the cost optimal fin width and thickness are not affected by either the meteorological conditions or the operating conditions and as such the obtained geometries are valid for any operating and meteorological conditions. Design nomographs presented serve as quick and convenient design tools for cost optimal flat-plate collector design.
(Design of cost optimal solar flat-plate collectors) Nijaguna, B.T.
1988