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01515 Preparation and crystallization of forsterite fibrous gels
13 Space heating and cooling The study was conducted using an EPA recommended sampling train and portable sampling tubes that were thermally desorbed and analysed by gas chromatography/mass spectrometry. Drying of raw sewage-sludge and firing processes were considered separately. This paper presents VOC emissions coming from the firing step of the Ecobrick ® production.
04101512 Large-area smart glass and integrated photovoltaics Lampert, C. M. Solar Energy Materials and Solar Cells, 2003, 76, (4), 489-499. Several companies throughout the world are developing dynamic glazing and large-area flat panel displays. University and National Laboratory groups are researching new materials and processes to improve these products. The concept of a switchable glazing for building and vehicle application is very attractive. Conventional glazing only offers fixed transmittance and control of energy passing through it. Given the wide range of illumination conditions and glare, a dynamic glazing with adjustable transmittance offers the best solution. Photovoltaics can be integrated as power sources for smart windows. In this way a switchable window could be a completely stand alone smart system. A new range of large-area flat panel display including lightweight and flexible displays are being developed. These displays can be used for banner advertising, dynamic pricing in stores, electronic paper, and electronic books, to name only a few applications. This study covers selected switching technologies including electrochromism, suspended particles, and encapsulated liquid crystals.
04/01513 Nature and role of natural alteration gels formed on the surface of ancient volcanic glasses (Natural analogs of waste containment glasses) Crovisier, J-L. et al. Journal of Nuclear Materials, 2003, 321, (1), 91109. This paper provides an overview of the geochemical alteration of basaltic glass, considered for over 20 years as a suitable natural analogue for nuclear borosilicate glasses. The available data show that natural basaltic glasses may survive for million of years under subsurface conditions. Mineralogical studies show that an alteration layer called palagonite forms on the surface of the basaltic in response to the chemical attack by water. Under some environmental conditions, the alteration layer consists of an amorphous gel-like material, leading many authors to suspect hydration of the glass by water permeation and alkali interdiffusion. In other cases, the alteration layer is crystallized to some extent and contains clay minerals (smectite). Such layers are formed mainly on the younger natural glass samples (< 1 My) by a process of co-precipitation of the elements dissolved from the glass. On samples older than 1 My, the alteration layers also contain zeolites. In the presence of these hydrated aluminosilicates, a hydrated residual glass is systematically observed, which thus forms as a consequence of interdiffusion processes. Leach tests conducted under controlled laboratory conditions at temperatures up to 200°C on both natural glass samples and synthetic basaltic glass provide identical kinetic results and alteration mechanisms. When compared with the data for SON68 nuclear borosilicate glass, the initial dissolution rates show the same activation energy (about 72 kJ tool -a) and consequently similar dissolution mechanisms. Moreover, when altered under static conditions at high reaction progress, both basaltic glass and nuclear glass have similar behaviour characterized by a significant drop in the dissolution rate, up to three to five orders of magnitude lower than the initial dissolution rate. The time-dependence of the thickness of the altered layers measured on natural glass samples confirms this kinetic trend over time: the long-term dissolution rate is very low. This decrease may be related to diffusion mechanisms involving key chemical species and controlled by the mineralogy of the palagonite layer.
04/01514 Physicochemical processes in blanket ceramic materials Tiliks, J. et al. Fusion Engineering and Design, 2003, 69, (1-4), 519-522. Effect of external magnetic field (MF) on important physieochemical processes in ceramic blanket materials, the Li4SiO4 (FZK) and LizTiO3 (CEA) ceramic pebbles, was studied. Stoichiometric amounts of the radiation-induced defects (RD) of the electron and hole type form at radiolysis of the ceramic materials. Colloid lithium forms only in Li4SiO4 under irradiation at the temperature 423-473 K and the dose 10-20 MGy. The magnetic field increases the radiolysis efficiency by 20-25% in both materials. The efficiency of formation of RD decreases with the increasing temperature of irradiation. Complete recombination of RD takes place at 873 K. The magnetic field retards the tritium release by lengthening the path of volume diffusion of char~ed tritium forms (T+). The substitution of 10 at.% of Ti 4+ by Nb 5~ produces additional cation vacancies in Li2TiO3 and increases the electrical conductivity by approximately 10 times at 1000 K. The constant of tritium diffusion is anticipated to be proportional to the electrical
206
Fuel and Energy Abstracts
May 2004
conductivity. The decrease of lithium content in Li2TiO3 ceramics simulating the lithium burn-up increases the electrical conductivity of ceramics.
04/01515 Preparation and crystallization of forsterite fibrous gels Tsai, M. T. Journal of the European Ceramic Society, 2003, 23, (8), 1283-1291. Transparent forsterite fibrous gels were prepared from the hydrolysis of alkoxide precursor sols with acetic acid and water, and the crystallization process of gel fibres was studied after heat treatment at _<1500°C. An appropriate amount of acetic acid not only promoted the formation of spinnable linear-type polymeric species, but also enhanced the chemical homogeneity and reduced the crystallization temperature of the resultant gels. On heating, fibrous gels started to crystallize into forsterite at 550°C as investigated by IR spectrum, Xray diffraction and thermal analysis. Single phase forsterite fibre thus could be obtained at _<1500°C when the amount of hydrolysis water was limited. However, fibrous gel derived from the high-water-content sol displayed a few secondary phases, i.e. magnesia (MgO) and protoenstatite (MgSiO3), following heating at 1000 and 1400°C, respectively; similarly, xerogels derived without acetic acid, or with insufficient amount of acetic acid, also revealed segregation of second phases on heating. The synthesized forsterite fibres displayed nanocrystal structure at _<1100°C. On heating to 1300°C, fired fibres exhibited grain growth to 0.3-0.5 ~tm in size, with room-temperature dielectric constants of 6.8-7.2 (at 1 MHz).
04/01516 Thermal and mechanical properties of Zrs2.sAIloNiloCulsBe12.s bulk metallic glass Xiao, X. et al. Journal of Alloys and Compounds, 2003, 351, (l 2), 324328. The formation, thermal stability and mechanical properties of Zrsz.sAla0Nil0CulsBel2.5 bulk amorphous alloy were investigated by means of X-ray diffraction, differential scanning calorimetry, D T A and tensile strength measurements. Compared with the Zr65Al10Ni10-Cu15 amorphous alloy, the substitution of 12.5 Be at. for part of the Zr results from an off-eutectic alloy composition into a eutectic one. This addition enhances the reduced glass transition temperature Trg (Tg/Tm) increase from 0.58 to 0.68, 6Tx from 105 to 142 K, and causes a change in fracture strength from 1.33 to 1.75 GPa. These results can be explained on the basis of thermodynamic and topological packing changes by the addition of Be.
13
SPACE HEATING A N D COOLING
04•01517 A review on energy conservation in building applications with thermal storage by latent heat using phase change materials Khudhair, A. M. and Farid, M. M. Energy Conversion and Management, 2004, 45, (2), 263-275. Energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating suitable phase change materials (PCMs) within these surfaces to capture solar energy directly and increase human comfort by decreasing the frequency of internal air temperature swings and maintaining the temperature closer to the desired temperature for a longer period of time. This paper summarizes the investigation and analysis of thermal energy storage systems incorporating PCMs for use in building applications. Researches on thermal storage in which the PCM is encapsulated in concrete, gypsum wallboard, ceiling and floor have been ongoing for some time and are discussed. The problems associated with the application of PCMs with regard to the selection of materials and the methods used to contain them are also discussed.
04/01518 A study of domestic energy usage patterns in Hong Kong Tso, G K. F. and Yau, K. K. W. Energy, 2003, 28, (15), 1671-1682. During the last decade, domestic energy consumption has increased substantially in Hong Kong, rising from 5718 GW h in 1991 to 9111 GW h in 2001. This study provides descriptive information on domestic energy usage patterns and investigates the effect of housing type, household characteristics and appliance ownership on electricity energy consumption level. Data were collected via a two-phase selfadministered diary survey. Due to Hong Kong's dense population and sub-tropical climate, energy consumption patterns are distinct from those of other countries. Electricity is the dominant type of energy consumption (63.7%), followed by Towngas (28.8%). Energy con-
04101512 Large-area smart glass and integrated photovoltaics Lampert, C. M. Solar Energy Materials and Solar Cells, 2003, 76, (4), 489-499. Several companies throughout the world are developing dynamic glazing and large-area flat panel displays. University and National Laboratory groups are researching new materials and processes to improve these products. The concept of a switchable glazing for building and vehicle application is very attractive. Conventional glazing only offers fixed transmittance and control of energy passing through it. Given the wide range of illumination conditions and glare, a dynamic glazing with adjustable transmittance offers the best solution. Photovoltaics can be integrated as power sources for smart windows. In this way a switchable window could be a completely stand alone smart system. A new range of large-area flat panel display including lightweight and flexible displays are being developed. These displays can be used for banner advertising, dynamic pricing in stores, electronic paper, and electronic books, to name only a few applications. This study covers selected switching technologies including electrochromism, suspended particles, and encapsulated liquid crystals.
04/01513 Nature and role of natural alteration gels formed on the surface of ancient volcanic glasses (Natural analogs of waste containment glasses) Crovisier, J-L. et al. Journal of Nuclear Materials, 2003, 321, (1), 91109. This paper provides an overview of the geochemical alteration of basaltic glass, considered for over 20 years as a suitable natural analogue for nuclear borosilicate glasses. The available data show that natural basaltic glasses may survive for million of years under subsurface conditions. Mineralogical studies show that an alteration layer called palagonite forms on the surface of the basaltic in response to the chemical attack by water. Under some environmental conditions, the alteration layer consists of an amorphous gel-like material, leading many authors to suspect hydration of the glass by water permeation and alkali interdiffusion. In other cases, the alteration layer is crystallized to some extent and contains clay minerals (smectite). Such layers are formed mainly on the younger natural glass samples (< 1 My) by a process of co-precipitation of the elements dissolved from the glass. On samples older than 1 My, the alteration layers also contain zeolites. In the presence of these hydrated aluminosilicates, a hydrated residual glass is systematically observed, which thus forms as a consequence of interdiffusion processes. Leach tests conducted under controlled laboratory conditions at temperatures up to 200°C on both natural glass samples and synthetic basaltic glass provide identical kinetic results and alteration mechanisms. When compared with the data for SON68 nuclear borosilicate glass, the initial dissolution rates show the same activation energy (about 72 kJ tool -a) and consequently similar dissolution mechanisms. Moreover, when altered under static conditions at high reaction progress, both basaltic glass and nuclear glass have similar behaviour characterized by a significant drop in the dissolution rate, up to three to five orders of magnitude lower than the initial dissolution rate. The time-dependence of the thickness of the altered layers measured on natural glass samples confirms this kinetic trend over time: the long-term dissolution rate is very low. This decrease may be related to diffusion mechanisms involving key chemical species and controlled by the mineralogy of the palagonite layer.
04/01514 Physicochemical processes in blanket ceramic materials Tiliks, J. et al. Fusion Engineering and Design, 2003, 69, (1-4), 519-522. Effect of external magnetic field (MF) on important physieochemical processes in ceramic blanket materials, the Li4SiO4 (FZK) and LizTiO3 (CEA) ceramic pebbles, was studied. Stoichiometric amounts of the radiation-induced defects (RD) of the electron and hole type form at radiolysis of the ceramic materials. Colloid lithium forms only in Li4SiO4 under irradiation at the temperature 423-473 K and the dose 10-20 MGy. The magnetic field increases the radiolysis efficiency by 20-25% in both materials. The efficiency of formation of RD decreases with the increasing temperature of irradiation. Complete recombination of RD takes place at 873 K. The magnetic field retards the tritium release by lengthening the path of volume diffusion of char~ed tritium forms (T+). The substitution of 10 at.% of Ti 4+ by Nb 5~ produces additional cation vacancies in Li2TiO3 and increases the electrical conductivity by approximately 10 times at 1000 K. The constant of tritium diffusion is anticipated to be proportional to the electrical
206
Fuel and Energy Abstracts
May 2004
conductivity. The decrease of lithium content in Li2TiO3 ceramics simulating the lithium burn-up increases the electrical conductivity of ceramics.
04/01515 Preparation and crystallization of forsterite fibrous gels Tsai, M. T. Journal of the European Ceramic Society, 2003, 23, (8), 1283-1291. Transparent forsterite fibrous gels were prepared from the hydrolysis of alkoxide precursor sols with acetic acid and water, and the crystallization process of gel fibres was studied after heat treatment at _<1500°C. An appropriate amount of acetic acid not only promoted the formation of spinnable linear-type polymeric species, but also enhanced the chemical homogeneity and reduced the crystallization temperature of the resultant gels. On heating, fibrous gels started to crystallize into forsterite at 550°C as investigated by IR spectrum, Xray diffraction and thermal analysis. Single phase forsterite fibre thus could be obtained at _<1500°C when the amount of hydrolysis water was limited. However, fibrous gel derived from the high-water-content sol displayed a few secondary phases, i.e. magnesia (MgO) and protoenstatite (MgSiO3), following heating at 1000 and 1400°C, respectively; similarly, xerogels derived without acetic acid, or with insufficient amount of acetic acid, also revealed segregation of second phases on heating. The synthesized forsterite fibres displayed nanocrystal structure at _<1100°C. On heating to 1300°C, fired fibres exhibited grain growth to 0.3-0.5 ~tm in size, with room-temperature dielectric constants of 6.8-7.2 (at 1 MHz).
04/01516 Thermal and mechanical properties of Zrs2.sAIloNiloCulsBe12.s bulk metallic glass Xiao, X. et al. Journal of Alloys and Compounds, 2003, 351, (l 2), 324328. The formation, thermal stability and mechanical properties of Zrsz.sAla0Nil0CulsBel2.5 bulk amorphous alloy were investigated by means of X-ray diffraction, differential scanning calorimetry, D T A and tensile strength measurements. Compared with the Zr65Al10Ni10-Cu15 amorphous alloy, the substitution of 12.5 Be at. for part of the Zr results from an off-eutectic alloy composition into a eutectic one. This addition enhances the reduced glass transition temperature Trg (Tg/Tm) increase from 0.58 to 0.68, 6Tx from 105 to 142 K, and causes a change in fracture strength from 1.33 to 1.75 GPa. These results can be explained on the basis of thermodynamic and topological packing changes by the addition of Be.
13
SPACE HEATING A N D COOLING
04•01517 A review on energy conservation in building applications with thermal storage by latent heat using phase change materials Khudhair, A. M. and Farid, M. M. Energy Conversion and Management, 2004, 45, (2), 263-275. Energy storage in the walls, ceiling and floor of buildings may be enhanced by encapsulating suitable phase change materials (PCMs) within these surfaces to capture solar energy directly and increase human comfort by decreasing the frequency of internal air temperature swings and maintaining the temperature closer to the desired temperature for a longer period of time. This paper summarizes the investigation and analysis of thermal energy storage systems incorporating PCMs for use in building applications. Researches on thermal storage in which the PCM is encapsulated in concrete, gypsum wallboard, ceiling and floor have been ongoing for some time and are discussed. The problems associated with the application of PCMs with regard to the selection of materials and the methods used to contain them are also discussed.
04/01518 A study of domestic energy usage patterns in Hong Kong Tso, G K. F. and Yau, K. K. W. Energy, 2003, 28, (15), 1671-1682. During the last decade, domestic energy consumption has increased substantially in Hong Kong, rising from 5718 GW h in 1991 to 9111 GW h in 2001. This study provides descriptive information on domestic energy usage patterns and investigates the effect of housing type, household characteristics and appliance ownership on electricity energy consumption level. Data were collected via a two-phase selfadministered diary survey. Due to Hong Kong's dense population and sub-tropical climate, energy consumption patterns are distinct from those of other countries. Electricity is the dominant type of energy consumption (63.7%), followed by Towngas (28.8%). Energy con-