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Abstract We screened several strains which exhibited significant photoorganotrophic growth on a chemically defined synthetic medium containing alcohols. Samples from sewage, rice fields, or other places were inoculated under anaerobic-light conditions at 30°C. After multiple enrichments, the growth characteristics of three fast growing isolates were investigated. We describe also the cloning of molecular chaperones from a purple non-sulfur bacterium.

Abstract This paper presents the exergy analysis of variable air volume (VAV) systems used in office buildings for air-conditioning. The mathematical models are developed using the engineering equations solver (EES) environment. The following indicators are presented: energy efficiency, exergy efficiency, and equivalent-CO 2 emissions due to the generation of electricity used by the VAV system.

Abstract For the safe and efficient operation of concentrator photovoltaic cells and electronic chips, low and uniform temperature should be attained. Therefore, the prime focus of this study is to design the optimal headers and to evaluate the performance of a monolithic double-layer microchannel heat sink (MDL-MCHS) operating under forced convective boiling conditions. The designed and fabricated heat sink was proved to attain a uniform temperature distribution over the entire surface of the MCHS heated wall, in a narrow temperature range around the coolant boiling point. The designs of the MCHS inlet and outlet headers were computationally optimized to avoid flow maldistribution over 10 parallel channels in each layer. Subsequently, an MDL-MCHS with an optimized header was fabricated using a metal 3D printer, and its thermal characteristics were experimentally evaluated in counterflow and parallel-flow operations under single-phase liquid flow and forced convective boiling conditions. The supplied heat flux was varied from 1.0 to 9.2 kW/m2. Ethanol and acetone with a boiling point of 78.4 °C or 56 °C were identically fed into each layer in a flowrate ( V ) range of 15–400 ml/h. At 9.2 kW/m2 (11.5 suns), the counterflow operation of forced convective boiling attained temperature uniformity below 1.6 °C and 1.8 °C in the V range of 25–100 ml/h for ethanol and 50–300 ml/h for acetone, respectively. The resultant wall temperature was nearly identical with the boiling point of operated coolant.

An analytical investigation of a high-temperature heat pump system was developed to estimate the thermal cycle and to assess the thermal fluids for their high-temperature delivery (up to 180°C) capacities without decomposition or the use of lubricant mechanisms. Then, a screw-type compressor was applied in the above conditions. Furthermore, a screw expander was also used as a replacement for the throttle valve [Taniguchi et al. J. Engng Gas Turbine and Power (ASME) 110, 628–635 (1988). In order to assess the performance of the heat pump system, leakage and friction effects had to be determined and simulated when using the screw machines. Numerical results of system tests are presented from cases where steam-water (for higher temperatures) and ammonia (for lower temperatures) were used as thermal fluids instead of normally used fluids such as halogenated chlorofluorocarbon, which has been implicated in the depletion of stratospheric ozone.

Abstract Many national energy projects have been pursued in Japan. Some of them are very important to control the emission of CO 2 from fossil fuel. The world energy network (WE-NET) project based on a hydrogen combustion gas turbine is one of the national projects and has a high target of thermal efficiency up to 60% or more (HHV) [Proc. IJPGC, Vol. 2, Baltimore, 1998, p. 293; Proc. IJPGC, Vol. 2, Baltimore, 1998, p. 433; Annual Summary Report on WE-NET, 1997; J. JSME, 100 (947) (1997) 1034; J. GTSJ, 27 (4) (1999) 217]. However, this new technology has to be developed by an application of a combined cycle for gas and steam turbines and special auxiliary equipment such as an oxygen supply plant and heat exchangers. The hydrogen combustion gas turbine will be operated by pure hydrogen and oxygen supplied and kept to produce a pure water vapor only. If other gaseous components are included in the combustion gas, the thermal efficiency of the combined cycle is decreased by the breakdown effect of a condenser vacuum. In this project, hydrogen may be imported from some foreign countries where it has to be produced by using clean and renewable energies, for example, hydropower or solar energy. On the other hand, the oxygen to be distilled from the air has to be supplied by auxiliary equipment of a liquid oxygen plant. This auxiliary equipment, however, will consume much power. In an existing type of the liquid oxygen plant, about 10% of the total power plant output has been consumed for the additional power of oxygen supply. In addition, the WE-NET combined cycle of the hydrogen combustion gas turbine will be supported by many heat exchangers that have to be checked for their technical problems. This paper has been highlighted at high performance design and setup of the major auxiliary equipment of the oxygen supply plant and the heat exchangers. The R&D prospect of their auxiliary equipment to attain a high thermal efficiency of the combined cycle in the WE-NET project will be discussed.

An experimental investigation to develop and test a burner and a heat recovery system for thermophotovoltaic (TPV) applications is presented. Experimental data have been compared with theoretical calculations and considerations in the pre-design and design phases of the project to find the weakest point of the concept and to validate the expected performance. The TPV generator has been designed as a compact module in order to be used as a range extender in an electric car. The heat recovery system is the key element to increase the efficiency of the system. The heat recovery system presented in this paper is a rotary type regenerator that is very compact and has higher effectiveness in comparison with other types of regenerators with the same number of transfer units (NTU). The experimental data have been used to verify the numerical models used in the calculations for design of the regenerator matrix. A new version of the numerical model has been developed to take into account the variation of the thermal properties of the system with the temperature. Dimensions, weight, efficiency, emissions and high working temperatures have been the most important competitive constraints to observe for design of the system.

Abstract Lipids produced by microalgae are a promising biofuel feedstock. However, as most commercial mass production of microalgae is in open raceway ponds it is generally considered only a practical option in regions where year-round ambient temperatures remain above 15 °C. To address this issue it has been proposed to couple microalgae production with industries that produce large amounts of waste heat and carbon dioxide (CO2). The CO2 would provide a carbon source for the microalgae and the waste heat would allow year-round cultivation to be extended to regions that experience seasonal ambient temperatures well below 15 °C. To demonstrate this concept, a dynamic model has been constructed that predicts the impact on algal pond temperature from both bubbled-in off-gas and heat indirectly recovered from off-gas. Simulations were carried out for a variety of global locations using the quantity off-gas and waste energy from a smelter’s operations to determine the volume of microalgae that could be maintained above 15 °C. The results demonstrate the feasibility of year-round microalgae production in climates with relatively cold winter seasons.