The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Roderick R Kunz - One of the best experts on this subject based on the ideXlab platform.
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characterization of nitrated Sugar Alcohols by atmospheric pressure chemical ionization mass spectrometry
Rapid Communications in Mass Spectrometry, 2017Co-Authors: Alla Ostrinskaya, Jude Kelley, Roderick R KunzAbstract:Abstract : RATIONALE: The nitrated Sugar Alcohols mannitol hexanitrate (MHN), sorbitol hexanitrate (SHN) and xylitol pentanitrate (XPN) are in the same class of compounds as the powerful military grade explosive pentaerythritol tetranitrate (PETN) and the homemade explosive erythritol tetranitrate (ETN), but unlike PETN and ETN the ways to detect MHN, SHN and XPN by mass spectrometry (MS) have not been fully investigated. METHODS: Atmospheric-pressure chemical-ionization mass spectrometry (APCI-MS) was used to detect ions characteristic of nitrated Sugar Alcohols. Time-of-flight APCI mass spectrometry (TOF APCI-MS) and collisional dissociation mass spectrometry (CID MSMS) were used for confirmation of each ion assignment. In addition, the use of the chemical ionization reagent dichloromethane was investigated to improve sensitivity and selectivity for MHN, SHN and XPN detection. RESULTS: All of the nitrated Sugar Alcohols studied followed similar fragmentation pathways in the APCI ionization source. MHN, SHN and XPN were detectable as fragment ions formed by the loss of NO2, HNO2, NO3, and CH2NO2 groups, and in the presence of dichloromethane chlorinated adduct ions were observed. It was determined that chlorinated adducts of MHN and SHN had the lowest limits of detection (LOD) while for XPN the lowest LOD was for detection of the [XPN-NO2] fragment ion. CONCLUSION: APCI-MS technique provides a selective and sensitive method for the detection of nitrated Sugar Alcohols. The methods disclosed here will benefit the area of explosives trace detection for counterterrorism and forensics.
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Characterization of nitrated Sugar Alcohols by atmospheric‐pressure chemical‐ionization mass spectrometry
Rapid Communications in Mass Spectrometry, 2017Co-Authors: Alla Ostrinskaya, Jude A Kelley, Roderick R KunzAbstract:Abstract : RATIONALE: The nitrated Sugar Alcohols mannitol hexanitrate (MHN), sorbitol hexanitrate (SHN) and xylitol pentanitrate (XPN) are in the same class of compounds as the powerful military grade explosive pentaerythritol tetranitrate (PETN) and the homemade explosive erythritol tetranitrate (ETN), but unlike PETN and ETN the ways to detect MHN, SHN and XPN by mass spectrometry (MS) have not been fully investigated. METHODS: Atmospheric-pressure chemical-ionization mass spectrometry (APCI-MS) was used to detect ions characteristic of nitrated Sugar Alcohols. Time-of-flight APCI mass spectrometry (TOF APCI-MS) and collisional dissociation mass spectrometry (CID MSMS) were used for confirmation of each ion assignment. In addition, the use of the chemical ionization reagent dichloromethane was investigated to improve sensitivity and selectivity for MHN, SHN and XPN detection. RESULTS: All of the nitrated Sugar Alcohols studied followed similar fragmentation pathways in the APCI ionization source. MHN, SHN and XPN were detectable as fragment ions formed by the loss of NO2, HNO2, NO3, and CH2NO2 groups, and in the presence of dichloromethane chlorinated adduct ions were observed. It was determined that chlorinated adducts of MHN and SHN had the lowest limits of detection (LOD) while for XPN the lowest LOD was for detection of the [XPN-NO2] fragment ion. CONCLUSION: APCI-MS technique provides a selective and sensitive method for the detection of nitrated Sugar Alcohols. The methods disclosed here will benefit the area of explosives trace detection for counterterrorism and forensics.
Bert M. Weckhuysen - One of the best experts on this subject based on the ideXlab platform.
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Base‐free Pd/TOMPP‐Catalyzed Telomerization of 1,3‐Butadiene with Carbohydrates and Sugar Alcohols
Chemsuschem, 2009Co-Authors: Peter J. C. Hausoul, Pieter C. A. Bruijnincx, Robertus J. M. Klein Gebbink, Bert M. WeckhuysenAbstract:Sugar and alcohol - a superior combo: The telomerization activity of the Pd/TOMPP catalyst is screened using thirteen different biomass-derived carbohydrates and Sugar Alcohols. High substrate conversions are achieved by using low Pd loading and without the use of an added base. In terms of butadiene conversion, a clear structure-activity relationship is found, which is in line with the series: Sugar Alcohols>sucrose>aldohexoses>aldopentoses>ketohexoses
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base free pd tompp catalyzed telomerization of 1 3 butadiene with carbohydrates and Sugar Alcohols
Chemsuschem, 2009Co-Authors: Peter J. C. Hausoul, Pieter C. A. Bruijnincx, Robertus J. M. Klein Gebbink, Bert M. WeckhuysenAbstract:Sugar and alcohol - a superior combo: The telomerization activity of the Pd/TOMPP catalyst is screened using thirteen different biomass-derived carbohydrates and Sugar Alcohols. High substrate conversions are achieved by using low Pd loading and without the use of an added base. In terms of butadiene conversion, a clear structure-activity relationship is found, which is in line with the series: Sugar Alcohols>sucrose>aldohexoses>aldopentoses>ketohexoses
Luisa F Cabeza - One of the best experts on this subject based on the ideXlab platform.
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stability of Sugar Alcohols as pcm for thermal energy storage
Solar Energy Materials and Solar Cells, 2014Co-Authors: Aran Solé, Stefan Niedermaier, Hannah Neumann, Ingrid Martorell, Peter Schossig, Luisa F CabezaAbstract:Sugar Alcohols as phase change materials (PCM) are very promising due to their high storage capacity, safety and economic reasons.Their phase change temperatures make them suitable for medium temperature storage, which is needed for solar process heat or waste heat recovery applications. To guarantee a long PCM working lifetime they should be tested under a repeated number of freezing/melting cycles to check whether the thermophysical properties remain constant or not. The cycling stability of D-mannitol, myo-inositol and galactitol has been studied with DSC and the chemical stability with FT-IR.Myo-inositol shows a good cycling stability under the chosen measuring parameters.The cycling and chemical stability of D-mannitol up to 20 cycles can be achieved by controlling some parameters. The variable affecting it the most is the amount of oxygen in contact with it. Hence, in the storage unit this could be prevented with an inert or vacuum atmosphere.
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Thermal stability test of Sugar Alcohols as phase change materials for medium temperature energy storage application
Energy Procedia, 2014Co-Authors: Aran Solé, Stefan Niedermaier, Hannah Neumann, Luisa F Cabeza, Elena PalomoAbstract:Sugar Alcohols are potential phase change materials candidates as they present high phase change enthalpy values, are non-toxic and low cost products. Three promising Sugar-Alcohols were selected: D-mannitol, myo-inositol and dulcitol under high melting enthalpy and temperature criterion. Thermal cycling tests were performed to study its cycling stability which can be determining when selecting the suitable phase change material. D-mannitol and dulcitol present poor thermal stability. Myo-inositol shows almost no decrease in thermal properties after 50 cycles for the heating process, however in the solidification part a decrease of 20 % of enthalpy and 11 % of temperature values is observed.
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Stability of Sugar Alcohols as PCM for thermal energy storage
Solar Energy Materials and Solar Cells, 2014Co-Authors: Aran Solé, Stefan Niedermaier, Hannah Neumann, Ingrid Martorell, Peter Schossig, Luisa F CabezaAbstract:Sugar Alcohols as phase change materials (PCM) are very promising due to their high storage capacity, safety and economic reasons. Their phase change temperatures make them suitable for medium temperature storage, which is needed for solar process heat or waste heat recovery applications. To guarantee a long PCM working lifetime they should be tested under a repeated number of freezing/melting cycles to check whether the thermophysical properties remain constant or not. The cycling stability of d-mannitol, myo-inositol and galactitol has been studied with DSC and the chemical stability with FT-IR. Myo-inositol shows a good cycling stability under the chosen measuring parameters. The cycling and chemical stability of d-mannitol up to 20 cycles can be achieved by controlling some parameters. The variable affecting it the most is the amount of oxygen in contact with it. Hence, in the storage unit this could be prevented with an inert or vacuum atmosphere. © 2014 Elsevier B.V.
Aran Solé - One of the best experts on this subject based on the ideXlab platform.
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stability of Sugar Alcohols as pcm for thermal energy storage
Solar Energy Materials and Solar Cells, 2014Co-Authors: Aran Solé, Stefan Niedermaier, Hannah Neumann, Ingrid Martorell, Peter Schossig, Luisa F CabezaAbstract:Sugar Alcohols as phase change materials (PCM) are very promising due to their high storage capacity, safety and economic reasons.Their phase change temperatures make them suitable for medium temperature storage, which is needed for solar process heat or waste heat recovery applications. To guarantee a long PCM working lifetime they should be tested under a repeated number of freezing/melting cycles to check whether the thermophysical properties remain constant or not. The cycling stability of D-mannitol, myo-inositol and galactitol has been studied with DSC and the chemical stability with FT-IR.Myo-inositol shows a good cycling stability under the chosen measuring parameters.The cycling and chemical stability of D-mannitol up to 20 cycles can be achieved by controlling some parameters. The variable affecting it the most is the amount of oxygen in contact with it. Hence, in the storage unit this could be prevented with an inert or vacuum atmosphere.
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Thermal stability test of Sugar Alcohols as phase change materials for medium temperature energy storage application
Energy Procedia, 2014Co-Authors: Aran Solé, Stefan Niedermaier, Hannah Neumann, Luisa F Cabeza, Elena PalomoAbstract:Sugar Alcohols are potential phase change materials candidates as they present high phase change enthalpy values, are non-toxic and low cost products. Three promising Sugar-Alcohols were selected: D-mannitol, myo-inositol and dulcitol under high melting enthalpy and temperature criterion. Thermal cycling tests were performed to study its cycling stability which can be determining when selecting the suitable phase change material. D-mannitol and dulcitol present poor thermal stability. Myo-inositol shows almost no decrease in thermal properties after 50 cycles for the heating process, however in the solidification part a decrease of 20 % of enthalpy and 11 % of temperature values is observed.
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Stability of Sugar Alcohols as PCM for thermal energy storage
Solar Energy Materials and Solar Cells, 2014Co-Authors: Aran Solé, Stefan Niedermaier, Hannah Neumann, Ingrid Martorell, Peter Schossig, Luisa F CabezaAbstract:Sugar Alcohols as phase change materials (PCM) are very promising due to their high storage capacity, safety and economic reasons. Their phase change temperatures make them suitable for medium temperature storage, which is needed for solar process heat or waste heat recovery applications. To guarantee a long PCM working lifetime they should be tested under a repeated number of freezing/melting cycles to check whether the thermophysical properties remain constant or not. The cycling stability of d-mannitol, myo-inositol and galactitol has been studied with DSC and the chemical stability with FT-IR. Myo-inositol shows a good cycling stability under the chosen measuring parameters. The cycling and chemical stability of d-mannitol up to 20 cycles can be achieved by controlling some parameters. The variable affecting it the most is the amount of oxygen in contact with it. Hence, in the storage unit this could be prevented with an inert or vacuum atmosphere. © 2014 Elsevier B.V.
Atsushi Fukuoka - One of the best experts on this subject based on the ideXlab platform.
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direct production of Sugar Alcohols from wood chips using supported platinum catalysts in water
Catalysis Communications, 2014Co-Authors: Aritomo Yamaguchi, Osamu Sato, Naoki Mimura, Hirokazu Kobayashi, Atsushi Fukuoka, Yoshihiko Hirosaki, Masayuki ShiraiAbstract:Abstract Softwood chips have been directly converted into Sugar Alcohols by supported platinum catalysts in water without any acid catalysts. The cellulose and hemicellulose in the wood chips were converted with 94% conversion and 62% yield and the lignin remained as solid after the reaction.
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production of Sugar Alcohols from real biomass by supported platinum catalyst
Catalysis Today, 2014Co-Authors: Hirokazu Kobayashi, Yukiyasu Yamakoshi, Yuto Hosaka, Mizuho Yabushita, Atsushi FukuokaAbstract:Abstract The influence of lignin and inorganic salts on the catalytic activity was studied in the hydrolytic hydrogenation of real biomass by a supported Pt catalyst. The direct conversion of raw silver grass by Pt/carbon catalyst under H 2 pressure produced small amounts of sorbitol (2.8 wt%), xylitol (7.3 wt%), and other Sugar Alcohols. It has been suggested that lignin reduces the reactivity of cellulose, as lignin exists together with cellulose in the biomass and both compounds are insoluble in water. Moreover, even weak bases drastically change the product distribution with more by-products such as EG and PG. Bases enhance the decomposition of Sugar intermediates and sorbitol. The removal of lignin and inorganic salts by alkali-explosion and neutralization raises the contents of cellulose and hemicellulose, thus increasing the yields of sorbitol (13 wt%) and xylitol (14 wt%) in the hydrolytic hydrogenation reactions.
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kinetic study of catalytic conversion of cellulose to Sugar Alcohols under low pressure hydrogen
Chemcatchem, 2014Co-Authors: Tasuku Komanoya, Hirokazu Kobayashi, Kenji Hara, Wangjae Chun, Atsushi FukuokaAbstract:Efficient hydrolytic hydrogenation of cellulose to Sugar Alcohols under low H2 pressures has remained a challenge. This article deals with the conversion of cellulose by using a carbon-supported Ru catalyst under H2 pressures as low as 0.7–0.9 MPa (absolute pressure at room temperature). Kinetic studies revealed that the Ru catalyst not only enhances the hydrolysis of cellulose to glucose and hydrogenation of glucose to Sugar Alcohols (sorbitol and mannitol), but also the degradation of Sugar Alcohols to C2–C6 polyols and gasses. The degradation path limits the total yield of Sugar Alcohols to less than 40 %. The yield of Sugar Alcohols is theoretically improved by increasing the ratio of the reaction rates of the cellulose hydrolysis, which is the rate-determining step in the reaction, to the decomposition. Thus, a mix-milling pretreatment of cellulose and the Ru catalyst together selectively accelerated the hydrolysis step and raised the yield up to 68 %, whereas the addition of acids in the cellulose conversion was less effective as a result of promotion of side-reactions. These results demonstrate superior applicability of the mix-milling treatment in the depolymerization of cellulose to its monomers.
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Kinetic Study of Catalytic Conversion of Cellulose to Sugar Alcohols under Low‐Pressure Hydrogen
Chemcatchem, 2013Co-Authors: Tasuku Komanoya, Hirokazu Kobayashi, Kenji Hara, Wangjae Chun, Atsushi FukuokaAbstract:Efficient hydrolytic hydrogenation of cellulose to Sugar Alcohols under low H2 pressures has remained a challenge. This article deals with the conversion of cellulose by using a carbon-supported Ru catalyst under H2 pressures as low as 0.7–0.9 MPa (absolute pressure at room temperature). Kinetic studies revealed that the Ru catalyst not only enhances the hydrolysis of cellulose to glucose and hydrogenation of glucose to Sugar Alcohols (sorbitol and mannitol), but also the degradation of Sugar Alcohols to C2–C6 polyols and gasses. The degradation path limits the total yield of Sugar Alcohols to less than 40 %. The yield of Sugar Alcohols is theoretically improved by increasing the ratio of the reaction rates of the cellulose hydrolysis, which is the rate-determining step in the reaction, to the decomposition. Thus, a mix-milling pretreatment of cellulose and the Ru catalyst together selectively accelerated the hydrolysis step and raised the yield up to 68 %, whereas the addition of acids in the cellulose conversion was less effective as a result of promotion of side-reactions. These results demonstrate superior applicability of the mix-milling treatment in the depolymerization of cellulose to its monomers.
