Showing papers in "Renewable Energy in 1994"

TL;DR: In this article, thermal energy storage in some fatty acids as phase-change materials has been investigated for a domestic water heating system, and the selected fatty acids were myristic acid, palmitic acid and stearic acid.

TL;DR: In this paper, a thermogravimetric analyzer was used to study the degradation of cellulose and formation of char and to derive the kinetic parameters, preexponential factor and activation energy in the presence of the metal salts.

TL;DR: The five computer programs TRNSYS, PRESIM, TRNSED, ONLINE and PREBID have been put together into a program package which is the most complete solar energy system modeling and simulation software that is available today.

TL;DR: In this paper, two modern designs of wind towers are considered which eliminate the above disadvantages of conventional wind towers, and one design incorporates one-way dampers in the tower head and a wetted column inside the tower.

TL;DR: In this article, two sky models, namely the isotropic model and the anisotropic model proposed by Hay and Davies, are used to calculate the diurnal profile of solar radiation intensity.

TL;DR: In this article, a mathematical model was developed for calculating the total radiation on a sloped surface and the model was then used to determine the optimum tilt angles for a flat plate collector and the optimal tilt and surface azimuth angles (orientation) for concentrating solar collectors in Assiut, Egypt on a daily basis, as well as for a specified period.

TL;DR: In this article, the possibility to use a dew collector for condensing atmospheric water vapour by exploiting the effect of radiative cooling has been studied and pigmented polymer foils with high solar reflectance and high thermal emittance were used.

TL;DR: In this paper, the statistical characteristics of wind at 10 locations in the Kingdom of Saudi Arabia are studied and the autocorrelation coefficients are computed and correlograms are found compatible with the real diurnal variation of mean wind speed for almost all the locations.

TL;DR: In this paper, pine wood was pyrolysed in an externally heated fluidised bed pyrolysis reactor with nitrogen as the fluidising gas, the results showed that the oils before catalysis were highly oxygenated, after catalysis the oils were markedly reduced in oxygenated species with an increase in aromatic species, producing a premium grade gasoline type fuel.

TL;DR: In this article, the authors discuss the parameters which should be considered in designing natural ventilation systems and present a procedure for calculating the air flow rate due to wind and buoyancy, which could have applications in ventilating commercial buildings.

TL;DR: In this paper, a linear model fitted to β vs TL for Athens is similar to the models reported for Avignon (France) and Dhahran (Saudi Arabia) and the variation in the monthly average values of β and TL is of similar trend to that of avignon and Saudi Arabia.

TL;DR: In this paper, a small solid adsorption solar refrigerator has been built and preliminary testing is underway, which contains 17 kg of active carbon and uses transparent insulation to reduce collector heat losses.

TL;DR: In this article, the authors summarize some of the work to date, examples of applications, monitoring results, new developments and provide insight as to why this technology has the potential to revolutionize building construction in the future.

TL;DR: In this paper, the performance of an active solar water heating system that uses a stratified storage tank in both natural and forced circulation operation modes was evaluated, and a new inlet diffuser design was used in the tank to enhance stratification, and compared to heating systems with other tank inlet designs.

TL;DR: In this article, a new correlation between the clearness index K t and the relative sunshine s/S is proposed for computing the monthly mean daily global radiation G (MJ m −2 day −1 ) at Italian locations.

TL;DR: In this article, the typical solar radiation year (TSRY) for Egypt is generated by using daily data of global solar radiation obtained by measurements at 10 stations for long periods, and hourly values of different components of solar radiation (direct, diffuse and global) over these 10 stations are estimated for the typical day (midday) of each month by applying empirical models and using the standard meteorological data for each station.

TL;DR: In this paper, the authors concluded that, in the UK at least, innovative daylighting systems should be designed primarily as shading devices, controlling glare while admitting more daylight than conventional blinds.

TL;DR: In this article, a theoretical model of an intermittent solar powered charcoal/methanol refrigerator has been developed to study its performance, which is used to investigate the heat and mass transfer in a tubular flat-plate collector (adsorber), which is heated by the sun and contains activated charcoal granules from which methanol is desorbed by heat.

TL;DR: In this article, the effect of chemical pretreatment and particle size on anaerobic digestion of bagasse and coconut fibres by rumen micro organisms was studied, and the suitability of using pretreated lignocellulosic waste biomas s as a substrate for methane production in a Rumen Derived Anaerobic Digestion-process was discussed.

TL;DR: The authors discusses objectives and principles for building design from human comfort aspects in regions with hot humid summers and mild winters and discusses issues such as building layout, openings and ventilation, orientation with respect to the sun and the wind, thermal mass, and special problems in Hurricane regions.

TL;DR: In this article, the authors introduced a wind diesel concept suitable for remote communities, the "Simple, Robust and Reliable Concept" developed at Riso, all components are standard components, the system is self regulating using the component controllers and there is no power electronics.

TL;DR: In this paper, a water slurry of cellulose was directly gasified into methane using reduced nickel on kieselguhr and sodium carbonate as catalysts at 400 °C under pressure (about 13 MPa) for 1 h.

TL;DR: In this paper, the authors developed a molecular photovoltaic device based on the sensitization of nanocrystalline films by transition metal charge transfer sensitizers, achieving an overall efficiency of 10% for solar energy conversion to electricity.

TL;DR: In this article, the main design questions for wind/diesel systems are discussed and the criteria affecting design choices for the diesel sets, wind turbines and energy stores are briefly discussed.

TL;DR: In this paper, the use of building thermal mass has been investigated in the context of air-conditioning in buildings and the potential of using a building's fabric as a thermal buffer to reduce summertime temperature swings.

TL;DR: In this article, the role of daylighting in modern architecture is discussed and a number of case study examples are presented to demonstrate the application of technology in case studies of modern architecture.

TL;DR: In this paper, the ILB is developing light-directing building components using holographic optical elements (HOE), which are produced on films, which are laminated between two panes of floatglass.

TL;DR: In this paper, a V-trough solar concentrator was combined with an inclined flat-plate wick-type solar still for outdoor testing on clear days in summer and winter.

TL;DR: In this article, the feasibility of incorporating a continuously variable transmission (C.V.T) between a wind turbine and an electric generator was investigated and the advantages of such a system in terms of efficiency were assessed.

TL;DR: In this article, the potentials of solar and wind energy were identified and the prime sites for wind energy are coastal area, arid zone and hill terrains, while solar energy is abundant over most part of the country, maximum being received over Quetta valley.