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01517 Pulsed laser deposition-assisted patterning of aligned carbon nanotubes modified by focused laser beam for efficient field emission
01 Solid fuels (derived solid fuels) microscope, scanning electron microscope, Raman spectroscopy and Infrared spectroscopy. Furthermore, the modified MWNTs were added to base lubricant and the tribological properties of resultant MWNTs lubricant were investigated by using a pin-on-plate wear tester. The results indicated that an esterification was formed in the oxidized MWNTs and SA, and the modification led to an improvement in the dispersion of MWNTs and the tribological properties of MWNTs as lubricant additive.
06/01516 Pulsed laser deposition of glass-like cluster assembled carbon films Bolgiaghi, D. et al. Carbon, 2005, 43, (9), 2122-2127. Carbon films have been synthesized at room temperature in helium atmosphere, at high pressure, on (1 0 0) Si substrates by pulsed KrF excimer laser ablation of highly oriented pyrolitic graphite. By changing laser power density (from 8.5 to 19 MW mm 2) and gas pressure (from 0.6 Pa to 2 kPa), nanometer sized cluster assembled films were obtained. Film morphology, as studied by scanning electron microscopy, changes with increasing helium pressure, from dense columns, to node-like morphology, then to an open dendritic structure. Carbon coordination was studied by visible Raman spectroscopy in all films. They are structurally disordered, sp 2 coordinated and belong to the family of glass-like carbons. The deduced film coherence length agrees with the average size of carbon aggregates that build up the films, as measured by transmission electron microscopy in representative samples. The average number of carbon atoms per cluster, that depends on helium (high) pressure, was obtained by a simple model.
06/01517 Pulsed laser deposition-assisted patterning of aligned carbon nanotubes modified by focused laser beam for efficient field emission Saurakhiya, N. et al. Carbon, 2005, 43, (10), 2128 2133. Patterned carbon nanotube (CNT) arrays have been synthesized on patterned substrates created via pulsed laser deposition (PLD) of the precursor catalyst films with a mask. Arrays of CNTs in square and hexagonal patterns with tube lengths of 8 ~tm and 16 ~tm were created on silicon or quartz substrates, respectively. Using the method of laser cutting, as-grown CNT patterns were pruned by focused H e - N e laser beam. It is found that after pruning, CNTs tend to cluster together and form welded junctions. The comparison of field emission properties of CNTs before and after pruning shows that laser modification of CNT morphologies effectively enhanced the emission currents.
06•01518 Sensitivity analysis of ozone long term simulations to grid resolution Bedogni, M. et al. International Journal o f Environment and Pollution, 2005, 24, (1-4), 36 50. In the frame of the CityDelta European modelling intercomparison, three different atmospheric chemistry transport models have been applied over the Milan Area for a 6-month summer simulation. To better evaluate the models' reliability and cleverness in simulating the long-term dynamics of pollutants in the atmosphere, a comprehensive sensitivity analysis with regard to all model configuration and input data has been carried out. This work deals particularly with the evaluation of the horizontal grid resolution influence (varying from 5 to 10 km). Results show that, in a flat area, ozone concentrations are quite insensitive to grid resolution as for mean values, while statistics of some extreme values are more sensible to horizontal model resolution. Nitrogen dioxide seems to be more sensitive than ozone, as it is more linked to emission spatial resolution.
06•01519 Separation and purification of functionalised water-soluble multi-walled carbon nanotubes by flow fieldflow fractionation Tagmatarchis, N. et al. Carbon, 2005, 43, (9), 1984 1989. Water-soluble, functionalized multi-walled carbon nanotubes (MWNT) have been separated and purified from amorphous material through direct flow field-fow fractionation. MWNT subpoputations of relatively homogeneous, different length were obtained by collecting fractions of the raw, highly polydispersed (200-5000 nm) functionalized MWNT sample.
06101520 ropes
Structure and energetics of carbon nanotube
Liu, Z. and Qin, L.-C. Carbon, 2005, 43, (10), 2146 2151. High-resolution electron microscopy observation and energetic analysis have been performed on ropes formed from single-walled carbon nanotubes. When individual nanotubes are twisted, the nanotube ropes
become energetically stable - a configuration that also offers better structural stability. Electron microscopic image simulations of an energetically stable rope composed of seven single-walled carbon nanotubes have been carried out as well to elaborate the salient features that were observed experimentally.
06•01521 Study on paraffin/expanded graphite composite phase change thermal energy storage material Zhang, Z. and Fang, X. Energy Conversion and Management, 2006, 47, (3), 303-310. A paraffin/expanded graphite composite phase change thermal energy storage material was prepared by absorbing the paraffin into an expanded graphite that has an excellent absorbability. In such a composite, the paraffin serves as a latent heat storage material and the expanded graphite acts as the supporting material, which prevents leakage of the melted paraffin from its porous structure due to the capillary and surface tension forces. The inherent structure of the expanded graphite did not change in the composite material. The solid-liquid phase change temperature of the composite PCM was the same as that of the paraffin, and the latent heat of the paraffin/ expanded graphite composite material was equivalent to the calculated value based on the mass ratio of the paraffin in the composite. The heat transfer rate of the paraffin/expanded graphite composite was obviously higher than that of the paraffin due to the combination with the expanded graphite that had a high thermal conductivity. The prepared paraffin/expanded graphite composite phase change material had a large thermal storage capacity and improved thermal conductivity and did not experience liquid leakage during its solid-liquid phase change.
06/01522 Templated synthesis of mesoporous carbon from sucrose - the way from the silica pore filling to the carbon material B6hme, K. et al. Carbon, 2005, 43, (9), 1918 1925. Mesoporous carbon materials were synthesized using sucrose as carbon precursor and commercial silica as template. Every step of the synthesis such as pore filling, loss of carbon precursor during carbonization and development of the carbon pore system during silica removal have been investigated in detail. As a criterion for the quality of the obtained carbon materials, the pore size distribution estimated by applying density functional theory was used.
06/01523 The influence of textural properties on the adsorption of hydrogen on ordered nanostructured carbons Gadiou, R. et al. Mieroporous attd Mesoporous Materials, 2005, 79, (13), 121 128. The design of an efficient hydrogen storage device is a major key point for the development of this fuel in mobile applications. Hydrogen physisorption on porous carbon materials is one among the different technologies which could be used. Although numerous types of carbon materials have been tested, the hydrogen adsorption capacities measured are far from reaching the goal proposed by the US D O E for transportation applications, that is 6.5 wt% at room temperature. In this study, ordered mesoporous carbon materials were synthesized by replication from organized mesoporous silicas. The combination of different templates and carbon precursors allowed to vary the textural properties of the samples. These materials were characterized by nitrogen and carbon dioxide adsorption, and their hydrogen storage capacity was measured at 77 K between 0.1 and 1 MPa. The best result was obtained by using sucrose as carbon precursor. The hydrogen weight percentage correlate well with the microporous volume determined by applying Dubinin-Radushkevich equation on CO2 adsorption isotherms showing the importance of ultramicropores (pore diameters below 1 nm). The evaluation of hydrogen density in the porous structure of the material shows also that there is a significant storage in supermicropores with diameters between 1 and 2 nm.
06101524 Transformation of fullerene peapods to doublewalled carbon nanotubes induced by UV radiation Kalb~c, M. et al. Carbon, 2005, 43, (8), 1610 1616. Double-walled carbon nanotubes were prepared by XeCl-laser irradiation of fullerene (C60 or C70) peapods. Raman spectroscopy evidences less defect structure of outer tubes, as compared to those in double-walled carbon nanotubes grown by thermal treatment of peapods. The diameter distribution also differs from that of the thermally prepared nanotubes. At the given laser fluence, the conversion of CT0@SWCNT into double-walled carbon nanotubes was more efficient than the corresponding conversion of C60@SWCNT.
Fuel and Energy Abstracts July 2006
237
06/01516 Pulsed laser deposition of glass-like cluster assembled carbon films Bolgiaghi, D. et al. Carbon, 2005, 43, (9), 2122-2127. Carbon films have been synthesized at room temperature in helium atmosphere, at high pressure, on (1 0 0) Si substrates by pulsed KrF excimer laser ablation of highly oriented pyrolitic graphite. By changing laser power density (from 8.5 to 19 MW mm 2) and gas pressure (from 0.6 Pa to 2 kPa), nanometer sized cluster assembled films were obtained. Film morphology, as studied by scanning electron microscopy, changes with increasing helium pressure, from dense columns, to node-like morphology, then to an open dendritic structure. Carbon coordination was studied by visible Raman spectroscopy in all films. They are structurally disordered, sp 2 coordinated and belong to the family of glass-like carbons. The deduced film coherence length agrees with the average size of carbon aggregates that build up the films, as measured by transmission electron microscopy in representative samples. The average number of carbon atoms per cluster, that depends on helium (high) pressure, was obtained by a simple model.
06/01517 Pulsed laser deposition-assisted patterning of aligned carbon nanotubes modified by focused laser beam for efficient field emission Saurakhiya, N. et al. Carbon, 2005, 43, (10), 2128 2133. Patterned carbon nanotube (CNT) arrays have been synthesized on patterned substrates created via pulsed laser deposition (PLD) of the precursor catalyst films with a mask. Arrays of CNTs in square and hexagonal patterns with tube lengths of 8 ~tm and 16 ~tm were created on silicon or quartz substrates, respectively. Using the method of laser cutting, as-grown CNT patterns were pruned by focused H e - N e laser beam. It is found that after pruning, CNTs tend to cluster together and form welded junctions. The comparison of field emission properties of CNTs before and after pruning shows that laser modification of CNT morphologies effectively enhanced the emission currents.
06•01518 Sensitivity analysis of ozone long term simulations to grid resolution Bedogni, M. et al. International Journal o f Environment and Pollution, 2005, 24, (1-4), 36 50. In the frame of the CityDelta European modelling intercomparison, three different atmospheric chemistry transport models have been applied over the Milan Area for a 6-month summer simulation. To better evaluate the models' reliability and cleverness in simulating the long-term dynamics of pollutants in the atmosphere, a comprehensive sensitivity analysis with regard to all model configuration and input data has been carried out. This work deals particularly with the evaluation of the horizontal grid resolution influence (varying from 5 to 10 km). Results show that, in a flat area, ozone concentrations are quite insensitive to grid resolution as for mean values, while statistics of some extreme values are more sensible to horizontal model resolution. Nitrogen dioxide seems to be more sensitive than ozone, as it is more linked to emission spatial resolution.
06•01519 Separation and purification of functionalised water-soluble multi-walled carbon nanotubes by flow fieldflow fractionation Tagmatarchis, N. et al. Carbon, 2005, 43, (9), 1984 1989. Water-soluble, functionalized multi-walled carbon nanotubes (MWNT) have been separated and purified from amorphous material through direct flow field-fow fractionation. MWNT subpoputations of relatively homogeneous, different length were obtained by collecting fractions of the raw, highly polydispersed (200-5000 nm) functionalized MWNT sample.
06101520 ropes
Structure and energetics of carbon nanotube
Liu, Z. and Qin, L.-C. Carbon, 2005, 43, (10), 2146 2151. High-resolution electron microscopy observation and energetic analysis have been performed on ropes formed from single-walled carbon nanotubes. When individual nanotubes are twisted, the nanotube ropes
become energetically stable - a configuration that also offers better structural stability. Electron microscopic image simulations of an energetically stable rope composed of seven single-walled carbon nanotubes have been carried out as well to elaborate the salient features that were observed experimentally.
06•01521 Study on paraffin/expanded graphite composite phase change thermal energy storage material Zhang, Z. and Fang, X. Energy Conversion and Management, 2006, 47, (3), 303-310. A paraffin/expanded graphite composite phase change thermal energy storage material was prepared by absorbing the paraffin into an expanded graphite that has an excellent absorbability. In such a composite, the paraffin serves as a latent heat storage material and the expanded graphite acts as the supporting material, which prevents leakage of the melted paraffin from its porous structure due to the capillary and surface tension forces. The inherent structure of the expanded graphite did not change in the composite material. The solid-liquid phase change temperature of the composite PCM was the same as that of the paraffin, and the latent heat of the paraffin/ expanded graphite composite material was equivalent to the calculated value based on the mass ratio of the paraffin in the composite. The heat transfer rate of the paraffin/expanded graphite composite was obviously higher than that of the paraffin due to the combination with the expanded graphite that had a high thermal conductivity. The prepared paraffin/expanded graphite composite phase change material had a large thermal storage capacity and improved thermal conductivity and did not experience liquid leakage during its solid-liquid phase change.
06/01522 Templated synthesis of mesoporous carbon from sucrose - the way from the silica pore filling to the carbon material B6hme, K. et al. Carbon, 2005, 43, (9), 1918 1925. Mesoporous carbon materials were synthesized using sucrose as carbon precursor and commercial silica as template. Every step of the synthesis such as pore filling, loss of carbon precursor during carbonization and development of the carbon pore system during silica removal have been investigated in detail. As a criterion for the quality of the obtained carbon materials, the pore size distribution estimated by applying density functional theory was used.
06/01523 The influence of textural properties on the adsorption of hydrogen on ordered nanostructured carbons Gadiou, R. et al. Mieroporous attd Mesoporous Materials, 2005, 79, (13), 121 128. The design of an efficient hydrogen storage device is a major key point for the development of this fuel in mobile applications. Hydrogen physisorption on porous carbon materials is one among the different technologies which could be used. Although numerous types of carbon materials have been tested, the hydrogen adsorption capacities measured are far from reaching the goal proposed by the US D O E for transportation applications, that is 6.5 wt% at room temperature. In this study, ordered mesoporous carbon materials were synthesized by replication from organized mesoporous silicas. The combination of different templates and carbon precursors allowed to vary the textural properties of the samples. These materials were characterized by nitrogen and carbon dioxide adsorption, and their hydrogen storage capacity was measured at 77 K between 0.1 and 1 MPa. The best result was obtained by using sucrose as carbon precursor. The hydrogen weight percentage correlate well with the microporous volume determined by applying Dubinin-Radushkevich equation on CO2 adsorption isotherms showing the importance of ultramicropores (pore diameters below 1 nm). The evaluation of hydrogen density in the porous structure of the material shows also that there is a significant storage in supermicropores with diameters between 1 and 2 nm.
06101524 Transformation of fullerene peapods to doublewalled carbon nanotubes induced by UV radiation Kalb~c, M. et al. Carbon, 2005, 43, (8), 1610 1616. Double-walled carbon nanotubes were prepared by XeCl-laser irradiation of fullerene (C60 or C70) peapods. Raman spectroscopy evidences less defect structure of outer tubes, as compared to those in double-walled carbon nanotubes grown by thermal treatment of peapods. The diameter distribution also differs from that of the thermally prepared nanotubes. At the given laser fluence, the conversion of CT0@SWCNT into double-walled carbon nanotubes was more efficient than the corresponding conversion of C60@SWCNT.
Fuel and Energy Abstracts July 2006
237