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00710 The influence of soil and coppice cycle on the rooting habit of short rotation poplar and willow coppice
07 Altemative energy sources (solar energy) reforming of cedar wood. As a result, Rh/CeO2/SiO2 gave higher yield of syngas than the conventional steam reforming Ni catalyst. Furthermore, the performance was compared between single and dual bed reactors. Single bed reactor was effective in the gasification of cedar, however, it was not suitable for the gasification of rice straw since a rapid deactivation was observed. Gasification of rice straw, jute stick, baggase using the fluidized dual-bed reactor and Rh/CeO2/SiO2 was also investigated. Especially, the catalyst stability in the gasification of rice straw clearly was enhanced by using the fluidized dual bed reactor.
05•00710 The influence of soil and coppice cycle on the rooting habit of short rotation poplar and willow coppice Crow, P. and Houston, T. J. Biomass and Bioenergy, 2004, 26, (6), 497505. The increased demand for renewable energy sources has led to large areas of former agricultural land being proposed for short rotation coppice (SRC) establishment. Concerns expressed over the potential impacts of tree roots on buried archaeological evidence led to a study into the rooting habit of SRC. Roots were exposed in trenches dug within a variety of willow and poplar clonal stands grown on brown earth, pelosol, ground-water gley and surface-water gley soils. Root depths and diameters were recorded in each of the 33 trenches. In total, over 18000 roots were measured on 264 coppice stools. The rotation length, species and stool location within a block were all found to influence the maximum size of root produced. Soil type had some influence on the root number and depth, but the pattern of root distribution down the soil profile was similar for both species.
Geothermal energy 05/00711 Experimental evaluation of a non-azeotropic working fluid for geothermal heat pump system Zhao, L. Energy Conversion and Management, 2004, 45, (9-10), 13691378. Geothermal energy resources are found in many countries. A reasonable and efficient utilization of these resources has been a worldwide concern. The application of geothermal heat pump systems (GHPS) can help increase the efficiency of using geothermal energy and reduce the thermal pollution to the earth surface. However, this is only possible with a proper working fluid. In this paper, a nonazeotropic working fluid (R290/R600a/R123) is presented for a GHPS where geothermal water at 40-45°C and heating network water at 7080°C serve as the low and high temperature heat sources. Experimental results show that the coefficient of performance (COP) of a GHPS using the working fluid is above 3.5 with the condensation temperature above 80°C and the condensation pressure below 18 bar, while the temperature of the geothermal water is reduced from 40-46°C to 31-36°C.
05/00712 Mathematical modeling for greenhouse heating by using thermal curtain and geothermal energy Ghosal, M. K. and Tiwari, G. N. Solar Energy, 2004, 76, (5), 603-613. A thermal model has been developed for the heating of a greenhouse by using inner thermal curtain and natural flow of geothermal warm water through the polyethylene tube laid on its floor. The calculations were done for a typical production greenhouse with the climatic data in the central part of Argentina during winter period. From the energy conservations point of view, the greenhouse has been divided into three zones i.e., zone I (plants under thermal blanket), zone II (space under ceiling) and zone III (space between roof and ceiling). The model has been tested with the published experimental data of air temperatures in zone I and zone II of the greenhouse. From the results, it was observed that the temperatures of air surrounding the plant mass in zone I were maintained in the range of 14-23°C during winter night and early morning resulting in the better growth of winter growing plants against the harmful freezing effects. The predicted values of air temperature both in zone I and zone II of the greenhouse obtained from the proposed model exhibited fair agreement with the published experimental values.
clastic sediments derived from the adjacent ranges, and a highly permeable, high-angle fault that functions as a conduit for subsurface fluids. This geometry is typical of Basin and Range extensional systems. The study characterizes the reservoir by utilizing several parameters, including temperature along the producing fault and the predicted surface heat flow. Time scales are on the order of 100 k year for development of maximum reservoir temperatures. However, if not sealed, significant geothermal systems can exist on a steady-state basis. The models show some features seen in Dixie Valley, Naveda, and explain observed relationships that young faults are frequently associated with extensional geothermal systems.
05100714 Precision gravity monitoring of the Bulalo geothermal field, Philippines: independent checks and constraints on numerical simulation Nordquist, G. et al. Geothermies, 2004, 33, (1-2), 37-56. Sixteen precision gravity surveys carried out since 1979 provide an additional constraint for numerical simulation of the Bulalo system. The gravity surveys were all run using the same LaCoste and Romberg gravity meter (D-33). Levelling surveys collected in conjunction with the gravity surveys used Wild N3 spirit levels. The levelling surveys were used to correct the gravity data for elevation changes. Since production began in 1979, the Bulalo field has experienced a gravity change of up to -600 microgal. The decline in gravity is interpreted to result from density changes in the reservoir, primarily due to the development of a two-phase zone where liquid saturation is lower in both the rock matrix and its fracture network. An accurate match of the trends and magnitudes of observed and simulated gravity changes provides a constraint for the mass balance of the numerical model beyond the matching of pressure and enthalpy evolution. Because of internal flow effects in most of the wells, pressure and temperature measurements do not necessarily represent static formation pressure and temperatures. Gravity data, therefore, became particularly important for calibrating the net depletion of the numerical model and for constraining reservoir mass replacement from re-injection and natural inflow from aquifers outside the production zone. Early comparisons of the observed and simulated gravity showed a too rapid gravity decrease prior to 1992, and a too slow gravity decrease after that time. Subsequent changes made to the numerical model, including modifying permeability structure and in-flow direction, resulted in an improved match to the gravity and available pressure data. The result has been a numerical model that accurately matches not only the quantity of net mass withdrawal, but also the location of the mass withdrawal including recharge from outside the producing reservoir.
05100715 Simulation of water-rock interaction in the Yellowstone geothermal system using TOUGHREACT Dobson, P. F. et al. Geothermics, 2004, 33, (4), 493-502. The Yellowstone geothermal system provides an ideal opportunity to test the ability of reactive transport models to simulate the chemical and hydrological effects of water-rock interaction. Previous studies of the Yellowstone geothermal system have characterized water-rock interaction through analysis of rocks and fluids obtained from both surface and downhole samples. Fluid chemistry, rock mineralogy, permeability, porosity, and thermal data obtained from the Y-8 borehole in Upper Geyser Basin were used to constrain a series of reactive transport simulations of the Yellowstone geothermal system using T O U G H R E A C T . Three distinct stratigraphic units were encountered in the 153.4 m deep Y-8 drill core: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous tuff. The main alteration phases identified in the Y-8 core samples include clay minerals, zeolites, silica polymorphs, adularia, and calcite. Temperatures observed in the Y-8 borehole increase with depth from subboiling conditions at the surface to a maximum of 169.8°C at a depth of 104.1 m, with near-isothermal conditions persisting down to the well bottom. 1-D models of the Y-8 core hole were constructed to simulate the observed alteration mineral assemblage given the initial rock mineralogy and observed fluid chemistry and temperatures. Preliminary simulations involving the perlitic rhyolitic lava unit are consistent with the observed alteration of rhyolitic glass to form celadonite.
Solar energy
05/00713 Numerical modeling of transient Basin and Range extensional geothermal systems McKenna, J. R. and Blackwell, D. D. Geothermics, 2004, 33, (4), 457476. A suite of models utilizing a simplified structural framework with a range of bulk rock permeabilities were developed to analyse the transient behaviour of Basin and Range extensional geothermal systems, and particularly, the evolution of the system temperature with time. Each model consists of two mountain ranges (~1 km relief from the valley floor) separated by a thick sequence (about 4 km) of
05/00716 A fuzzy global efficiency optimization of a photovoltaic water pumping system Benlarbi, K. et al. Solar Energy, 2004, 77, (2), 203-216. This paper presents an on-line fuzzy optimization of the global efficiency of a photovoltaic water pumping system driven by a separately excited DC motor (DCM), a permanent magnet synchronous motor (PMSM), or an induction motor (IM), coupled to a centrifugal pump. The fuzzy optimization procedure stated above,
Fuel and Energy Abstracts March 2005
105
05•00710 The influence of soil and coppice cycle on the rooting habit of short rotation poplar and willow coppice Crow, P. and Houston, T. J. Biomass and Bioenergy, 2004, 26, (6), 497505. The increased demand for renewable energy sources has led to large areas of former agricultural land being proposed for short rotation coppice (SRC) establishment. Concerns expressed over the potential impacts of tree roots on buried archaeological evidence led to a study into the rooting habit of SRC. Roots were exposed in trenches dug within a variety of willow and poplar clonal stands grown on brown earth, pelosol, ground-water gley and surface-water gley soils. Root depths and diameters were recorded in each of the 33 trenches. In total, over 18000 roots were measured on 264 coppice stools. The rotation length, species and stool location within a block were all found to influence the maximum size of root produced. Soil type had some influence on the root number and depth, but the pattern of root distribution down the soil profile was similar for both species.
Geothermal energy 05/00711 Experimental evaluation of a non-azeotropic working fluid for geothermal heat pump system Zhao, L. Energy Conversion and Management, 2004, 45, (9-10), 13691378. Geothermal energy resources are found in many countries. A reasonable and efficient utilization of these resources has been a worldwide concern. The application of geothermal heat pump systems (GHPS) can help increase the efficiency of using geothermal energy and reduce the thermal pollution to the earth surface. However, this is only possible with a proper working fluid. In this paper, a nonazeotropic working fluid (R290/R600a/R123) is presented for a GHPS where geothermal water at 40-45°C and heating network water at 7080°C serve as the low and high temperature heat sources. Experimental results show that the coefficient of performance (COP) of a GHPS using the working fluid is above 3.5 with the condensation temperature above 80°C and the condensation pressure below 18 bar, while the temperature of the geothermal water is reduced from 40-46°C to 31-36°C.
05/00712 Mathematical modeling for greenhouse heating by using thermal curtain and geothermal energy Ghosal, M. K. and Tiwari, G. N. Solar Energy, 2004, 76, (5), 603-613. A thermal model has been developed for the heating of a greenhouse by using inner thermal curtain and natural flow of geothermal warm water through the polyethylene tube laid on its floor. The calculations were done for a typical production greenhouse with the climatic data in the central part of Argentina during winter period. From the energy conservations point of view, the greenhouse has been divided into three zones i.e., zone I (plants under thermal blanket), zone II (space under ceiling) and zone III (space between roof and ceiling). The model has been tested with the published experimental data of air temperatures in zone I and zone II of the greenhouse. From the results, it was observed that the temperatures of air surrounding the plant mass in zone I were maintained in the range of 14-23°C during winter night and early morning resulting in the better growth of winter growing plants against the harmful freezing effects. The predicted values of air temperature both in zone I and zone II of the greenhouse obtained from the proposed model exhibited fair agreement with the published experimental values.
clastic sediments derived from the adjacent ranges, and a highly permeable, high-angle fault that functions as a conduit for subsurface fluids. This geometry is typical of Basin and Range extensional systems. The study characterizes the reservoir by utilizing several parameters, including temperature along the producing fault and the predicted surface heat flow. Time scales are on the order of 100 k year for development of maximum reservoir temperatures. However, if not sealed, significant geothermal systems can exist on a steady-state basis. The models show some features seen in Dixie Valley, Naveda, and explain observed relationships that young faults are frequently associated with extensional geothermal systems.
05100714 Precision gravity monitoring of the Bulalo geothermal field, Philippines: independent checks and constraints on numerical simulation Nordquist, G. et al. Geothermies, 2004, 33, (1-2), 37-56. Sixteen precision gravity surveys carried out since 1979 provide an additional constraint for numerical simulation of the Bulalo system. The gravity surveys were all run using the same LaCoste and Romberg gravity meter (D-33). Levelling surveys collected in conjunction with the gravity surveys used Wild N3 spirit levels. The levelling surveys were used to correct the gravity data for elevation changes. Since production began in 1979, the Bulalo field has experienced a gravity change of up to -600 microgal. The decline in gravity is interpreted to result from density changes in the reservoir, primarily due to the development of a two-phase zone where liquid saturation is lower in both the rock matrix and its fracture network. An accurate match of the trends and magnitudes of observed and simulated gravity changes provides a constraint for the mass balance of the numerical model beyond the matching of pressure and enthalpy evolution. Because of internal flow effects in most of the wells, pressure and temperature measurements do not necessarily represent static formation pressure and temperatures. Gravity data, therefore, became particularly important for calibrating the net depletion of the numerical model and for constraining reservoir mass replacement from re-injection and natural inflow from aquifers outside the production zone. Early comparisons of the observed and simulated gravity showed a too rapid gravity decrease prior to 1992, and a too slow gravity decrease after that time. Subsequent changes made to the numerical model, including modifying permeability structure and in-flow direction, resulted in an improved match to the gravity and available pressure data. The result has been a numerical model that accurately matches not only the quantity of net mass withdrawal, but also the location of the mass withdrawal including recharge from outside the producing reservoir.
05100715 Simulation of water-rock interaction in the Yellowstone geothermal system using TOUGHREACT Dobson, P. F. et al. Geothermics, 2004, 33, (4), 493-502. The Yellowstone geothermal system provides an ideal opportunity to test the ability of reactive transport models to simulate the chemical and hydrological effects of water-rock interaction. Previous studies of the Yellowstone geothermal system have characterized water-rock interaction through analysis of rocks and fluids obtained from both surface and downhole samples. Fluid chemistry, rock mineralogy, permeability, porosity, and thermal data obtained from the Y-8 borehole in Upper Geyser Basin were used to constrain a series of reactive transport simulations of the Yellowstone geothermal system using T O U G H R E A C T . Three distinct stratigraphic units were encountered in the 153.4 m deep Y-8 drill core: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous tuff. The main alteration phases identified in the Y-8 core samples include clay minerals, zeolites, silica polymorphs, adularia, and calcite. Temperatures observed in the Y-8 borehole increase with depth from subboiling conditions at the surface to a maximum of 169.8°C at a depth of 104.1 m, with near-isothermal conditions persisting down to the well bottom. 1-D models of the Y-8 core hole were constructed to simulate the observed alteration mineral assemblage given the initial rock mineralogy and observed fluid chemistry and temperatures. Preliminary simulations involving the perlitic rhyolitic lava unit are consistent with the observed alteration of rhyolitic glass to form celadonite.
Solar energy
05/00713 Numerical modeling of transient Basin and Range extensional geothermal systems McKenna, J. R. and Blackwell, D. D. Geothermics, 2004, 33, (4), 457476. A suite of models utilizing a simplified structural framework with a range of bulk rock permeabilities were developed to analyse the transient behaviour of Basin and Range extensional geothermal systems, and particularly, the evolution of the system temperature with time. Each model consists of two mountain ranges (~1 km relief from the valley floor) separated by a thick sequence (about 4 km) of
05/00716 A fuzzy global efficiency optimization of a photovoltaic water pumping system Benlarbi, K. et al. Solar Energy, 2004, 77, (2), 203-216. This paper presents an on-line fuzzy optimization of the global efficiency of a photovoltaic water pumping system driven by a separately excited DC motor (DCM), a permanent magnet synchronous motor (PMSM), or an induction motor (IM), coupled to a centrifugal pump. The fuzzy optimization procedure stated above,
Fuel and Energy Abstracts March 2005
105