摘要:

AbstractA two‐compartment electrochemical photocell using nickel‐based polycrystalline CdSe, CdS, and mixed chalcogenides showed promising potential for constructing regenerative and/or storage batteries. The cell was able to generate photovoltages of up to 700 mV and photocurrent of 2–6 mA/cm2when different aqueous electrolytes were used in the dark compartment. The illuminated compartment was filled with polysulphide electrolyte and light intensity used was 70 mW/cm2. Properties such as the open‐circuit voltage, the short‐circuit current, the efficiency, and the effect of applied voltages in different redox couples are

ISSN:0363-907X    

DOI:10.1002/er.4440140102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThere seems to be some question concerning the relationship between irrigation and the price of energy. Did changes in the price of energy actually impact irrigation in the USA? Additionally, the substitution between alternative types of energy seems to be a possibility for irrigation. Whether in fact it occurred is another matter. In this study, an appropriate model is developed and estimated to address the issues. The specific energy types considered include motor gasoline, diesel fuel, liquefied petroleum gas, natural gas and electrical energy. The results for 1978 and for 1980 clearly indicate that energy use for irrigation is responsive to the price of energy. Additionally, some substitution between energy types took place during this period. Finally, when the question of the stability of the demand for the various energy types is addressed, the suggestion is that the demand for the energy types considered was stable for the 1978 and 1980 periods.

ISSN:0363-907X    

DOI:10.1002/er.4440140103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe velocity and temperature profiles for an impulsively started Couette flow have been derived for a fluid with a high and strongly temperature‐dependent viscosity when the flow takes place through a porous medium. The steady as well as the transient state flows are discussed and the influence of the medium permeability is assessed. In the steady state the presence of the porous medium causes higher maximum temperatures only for sufficiently low permeabilities and in all cases significantly lower velocity profiles. The flow development times tend to be higher for the low permeabilities only for high Nahme numbers. For the transient state it is noticeable that, in all cases, the velocity develops much more rapidly than the temperature and that the presence of the porous medium accelerates this tendency. Finally the medium permeability produces skew temperature profiles and higher temperature time gradients at all time

ISSN:0363-907X    

DOI:10.1002/er.4440140104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe performance of the heat exchangers of an unsophisticated air‐air heat pump are examined with particular emphasis on the evaporator frosting characteristics. The data relate to an operating domestic heat pump in Dunedin. Evaporator frosting reduces the seasonal COP by only a small amount (less than 1.7%) in this example but the defrost rate is shown to be very sensitive to small changes in the evaporator capacity. Thus frost formation generally has an important influence on the evaporator optimization calculation. The effectiveness of the expansion valve and of the defrost thermostat is also analysed, and particular opportunities for improving the system are identifie

ISSN:0363-907X    

DOI:10.1002/er.4440140105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe paper focuses on the effect that the elimination of the windfall profits tax (WPT) on crude oil would have on the various producing sectors, consuming sectors and household categories in the USA, where the interrelationships between these entities are explicitly considered. Special attention is given to the agricultural sectors of the economy. Thus, in the context of a general equilibrium model, the effect of the elimination of the WPT on the producing sectors in general and the three agricultural sectors plus forestry in particular, on the consuming sectors, on households and on the Government is calculated. Over the period 1984–1990, such a policy initiative would result in higher output by the non‐crude‐oil producing sectors (by about $1.783 billion), higher consumption of goods and services (by about $1.651 billion), and an increase in welfare (by about $1.625 billion). The Government will realize a decrease in revenue of about $1.362 billion while the domestic crude oil industry will experience an increase in output of approximately $1.217 billion. For the agricultural sectors, output overall will fall. Specifically, for the programme crops sector, output will decline by $39 million, for the livestock sector, output will fall by $14 million, for all other agricultural commodities, output will decline by $36 million and for forestry, output will be reduced by $29 million. Attendant on these reductions in output will be lower prices for the respective commod

ISSN:0363-907X    

DOI:10.1002/er.4440140106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractAn approximate solution to oscillatory flow past a porous horizontal plate was carried out under the following conditions(i)Constant suction(ii)Stratification of the medium due to change in density, viscosity and thermal conductivity(iii)Free‐stream oscillation about a nonzero constant mean.Solutions have been derived for the transient velocity, the transient temperature, the amplitude and the phase of skin friction and the amplitude and phase of the first and second harmonics of the rate of heat transfer. These are shown on the graphs. The effects of the suction parameterS, the stratification parameter λ, the frequency λ and the Eckert number E are discus

ISSN:0363-907X    

DOI:10.1002/er.4440140107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractThe output parameters of an experimental fission electric cell (FEC) operating in the current generator mode have been estimated for the values of the neutron flux existing in the nuclear reactors. The estimation has been performed on the basis of the experimental values obtained in an investigation carried out at the Central Institute of Physcis (CIP) in Bucharest, Romania, concentrating on direct nuclear fission energy conversion into electrical energy. These experimental values are higher by orders of magnitude than those reported by other laboratories.The results of the estimation indicate that hundreds of microamperes, hundreds of kilovolts and hundreds of watts could be delivered by an FEC containing 1g of235U and irradiated in a thermal neutron flux of 1.4 × 1013neutron cm−2s−1.The research demonstrates the feasibility of efficient fission electric cells as potentially usable components in nuclear reac

ISSN:0363-907X    

DOI:10.1002/er.4440140108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractAn experimental study was carried out on a central plant for the heating of domestic hot water for a block of 143 flats and 15 offices. The behaviour of the condensing boilers serving the plant was examined and the energy costs of recirculation and distribution were analysed. Since the losses due to recirculation are of the same order as the useful energy, the influence of the various parameters on the losses has been studied, and some methods of lowering them are proposed.

ISSN:0363-907X    

DOI:10.1002/er.4440140109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractWorld and regional economic growth progressed at annual rates above 4% in the period 1948–73, and this was accompanied by strong growth of demand for all forms of commercial energy. Since 1973, or perhaps later, energy growth trends declined substantially below economic growth rates, but this was determined by rates and types of growth.A convenient method of describing this apparent separation of energy, and particularly oil, from economic growth is to use the term ‘decoupling’: economic growth was ‘coupled’ with energy before 1973, and ‘decoupled’ after.Even on a purely theoretical energy‐economic basis this apparent structural change is based on an internal dynamic of factors that will tend to ‘recouple’ energy demand with economic growth. This is particularly the case with non‐OECD countries, and especially developing countries.Within the OECD nations, since 1979, a relatively coherent case can be advanced for ‘decoupling’. However, using the examples of the US and Japanese economies, it is observed that the period since 1984 has been increasingly ‘coupled’. For the period 1978–88 a generalized U‐shaped evolution of annual energy‐GDP elasticities, or coefficients, is noted. This has significant implications for near‐term energy demand, particularly oil, and thus for oil price change.At the world level, and depending on the definition of ‘decoupling’, it is suggested that this trend, due to cyclic, structural and secular changes, is rather weak. Conversely, the impact of macroeconomic policy of the OECD nations on world energy is strong, because the nature and scale of economic growth directly determines energy demand. If this is the real meaning of ‘coupling’, the response of the energy economy to the rest of the economy, then there has ne

ISSN:0363-907X    

DOI:10.1002/er.4440140110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY

摘要:

AbstractTwo different approaches for designing a linear Fresnel reflector solar concentrator (LFRSC) with a flat horizontal absorber are described. The performance characteristics of both the designs are studied in detail. The distribution of local concentration ratio on the surface of the absorber, for each design, is investigated using the ray trace technique. Results of some typical numerical calculations are presented graphically and discussed.

ISSN:0363-907X    

DOI:10.1002/er.4440140111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1990

数据来源: WILEY