The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Abraham F. Jalbout - One of the best experts on this subject based on the ideXlab platform.
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density functional computational studies on the glucose and glycine maillard Reaction Formation of the amadori rearrangement products
International Journal of Quantum Chemistry, 2008Co-Authors: Abraham F. Jalbout, Abul Haider Shipar, Samsuddin M AhmedAbstract:Theoretical energy changes of various intermediates leading to the Formation of the Amadori rearrangement products (ARPs) under different mechanistic assumptions have been calculated, by using open chain glucose (O-Glu)/closed chain glucose (A-Glu and B-Glu) and glycine (Gly) as a model for the Maillard Reaction. Density functional theory (DFT) computations have been applied on the proposed mechanisms under different pH conditions. Thus, the possibility of the Formation of different compounds and electronic energy changes for different steps in the proposed mechanisms has been evaluated. B-Glu has been found to be more efficient than A-Glu, and A-Glu has been found more efficient than O-Glu in the Reaction. The Reaction under basic condition is the most favorable for the Formation of ARPs. Other Reaction pathways have been computed and discussed in this work. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
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density functional computational studies on ribose and glycine maillard Reaction Formation of the amadori rearrangement products in aqueous solution
Food Chemistry, 2007Co-Authors: Abraham F. Jalbout, Md Abul Haider Shipar, José Luis NavarroAbstract:By following the Hodge-scheme, and considering the Formation of the Amadori rearrangement products (ARPs) as one of the possible intermediates in the early stage, density functional theory calculations have been performed at the standard state on the proposed mechanisms of the Maillard Reaction of cyclic ribose (c-Rib)/open-chain ribose (Rib) and glycine species under different pH conditions in aqueous solution. The result reveals that both c-Rib and Rib can participate in the Reaction. Rib has been found as more reactive than c-Rib in the Reaction. The Reactions under basic and neutral conditions are supposed to be the most and second most favourable for the Formation of ARPs. Production of both of the enol and keto forms of ARP have been found as feasible under basic condition, whereas the neutral condition is only favourable for producing the enol form of ARP. Therefore, the rate of browning under basic condition is assumed higher than that of the neutral condition. Formation of all intermediates in the proposed mechanisms has been found as unfeasible in the Reaction under acidic condition and at the isoelectric point of glycine. Therefore, production of ARPs under these conditions is assumed to be stalled under these conditions, resulting into lower browning rate. Formation of Rib through the cleavage of glucose has been assumed less feasible than the Formation of glucose from Rib and formaldehyde in aqueous solution.
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Density functional computational studies on the intermediate stage of the ribose and glycine Maillard Reaction: Formation of deoxyosones in aqueous solution
Food Chemistry, 2007Co-Authors: Abraham F. Jalbout, Abul Haider Shipar, Flavio F. Contreras-torresAbstract:Mechanisms in an aqueous solution of the Maillard Reaction are proposed under several pH conditions for the interaction of glycine with cyclic ribose (c-Rib) and open-chain ribose (Rib). According to the Gibbs free energy relationships as well as internal energies values derived from our density functional theory calculations, the c-Rib/Rib + DGly (glycine) are the most favourable Reaction pathways for the Formation of deoxyosones under basic conditions, where Rib is more reactive than c-Rib. The intermediate stage of the Maillard Reaction leads to the Formation of deoxyosones.
José Luis Navarro - One of the best experts on this subject based on the ideXlab platform.
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density functional computational studies on ribose and glycine maillard Reaction Formation of the amadori rearrangement products in aqueous solution
Food Chemistry, 2007Co-Authors: Abraham F. Jalbout, Md Abul Haider Shipar, José Luis NavarroAbstract:By following the Hodge-scheme, and considering the Formation of the Amadori rearrangement products (ARPs) as one of the possible intermediates in the early stage, density functional theory calculations have been performed at the standard state on the proposed mechanisms of the Maillard Reaction of cyclic ribose (c-Rib)/open-chain ribose (Rib) and glycine species under different pH conditions in aqueous solution. The result reveals that both c-Rib and Rib can participate in the Reaction. Rib has been found as more reactive than c-Rib in the Reaction. The Reactions under basic and neutral conditions are supposed to be the most and second most favourable for the Formation of ARPs. Production of both of the enol and keto forms of ARP have been found as feasible under basic condition, whereas the neutral condition is only favourable for producing the enol form of ARP. Therefore, the rate of browning under basic condition is assumed higher than that of the neutral condition. Formation of all intermediates in the proposed mechanisms has been found as unfeasible in the Reaction under acidic condition and at the isoelectric point of glycine. Therefore, production of ARPs under these conditions is assumed to be stalled under these conditions, resulting into lower browning rate. Formation of Rib through the cleavage of glucose has been assumed less feasible than the Formation of glucose from Rib and formaldehyde in aqueous solution.
N Ravet - One of the best experts on this subject based on the ideXlab platform.
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Mechanism of the Fe3+ reduction at low temperature for LiFePO4 synthesis from a polymeric additive
Chemistry of Materials, 2007Co-Authors: N Ravet, Michel Gauthier, K Zaghib, John B Goodenough, Alain Mauger, Francois Gendron, C JulienAbstract:Comparison is made between the use of either a carbon powder or a polymer additive to the precursors in the synthesis of LiFePO4 from the Fe(III) compound FePO4(H2O)(2) and Li2CO3. The evolution of the structural properties and phase purity with temperature and time have been monitored at all length scales by X-ray diffraction, Fourier transformed infrared spectroscopy, and magnetic susceptibility. The reactor temperature was decreased to 300 degrees C to investigate the early stages of the Reaction. Formation of crystalline LiFePO4 begins in the range 300-400 degrees C only if the polymer is used as the carbonaceous additive. This LiFePO4 Formation is made possible by the reduction of Fe(III) species by gases such as H-2 or gaseous hydrocarbons evolved during the calcination of the polymer. Moreover, decomposition of the polymer results in a carbonaceous deposit on the surface of the LiFePO4 particles. An Li3Fe2(PO4)(3) impurity found after sintering at 400 degrees C for 4 h was greatly reduced after sintering at 400 degrees C for 24 h, and phase-pure LiFePO4 was attained at 700 degrees C. Where the solid carbon powder was used as the reducing agent, no Fe(II) species could be detected after sintering at 400 degrees C. Carbothermal reduction of Fe(III) is ruled out in this temperature range.
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mechanism of the fe3 reduction at low temperature for lifepo4 synthesis from a polymeric additive
Chemistry of Materials, 2007Co-Authors: N Ravet, Michel Gauthier, K Zaghib, John B Goodenough, Alain Mauger, Francois Gendron, C JulienAbstract:Comparison is made between the use of either a carbon powder or a polymer additive to the precursors in the synthesis of LiFePO4 from the Fe(III) compound FePO4(H2O)2 and Li2CO3. The evolution of the structural properties and phase purity with temperature and time have been monitored at all length scales by X-ray diffraction, Fourier transformed infrared spectroscopy, and magnetic susceptibility. The reactor temperature was decreased to 300 °C to investigate the early stages of the Reaction. Formation of crystalline LiFePO4 begins in the range 300−400 °C only if the polymer is used as the carbonaceous additive. This LiFePO4 Formation is made possible by the reduction of Fe(III) species by gases such as H2 or gaseous hydrocarbons evolved during the calcination of the polymer. Moreover, decomposition of the polymer results in a carbonaceous deposit on the surface of the LiFePO4 particles. An Li3Fe2(PO4)3 impurity found after sintering at 400 °C for 4 h was greatly reduced after sintering at 400 °C for 24 h,...
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Mechanism of the Fe Reduction at Low Temperature for LiFePO Synthesis from a Polymeric Additive
Chemistry of Materials, 2007Co-Authors: N Ravet, K Zaghib, John B Goodenough, Alain Mauger, Francois Gendron, Mélanie Gauthier, C.m. JulienAbstract:Comparison is made between the use of either a carbon powder or a polymer additive to the precursors in the synthesis of LiFePO4 from the Fe(III) compound FePO4(H2O)2 and Li2CO3. The evolution of the structural properties and phase purity with temperature and time have been monitored at all length scales by X-ray diffraction, Fourier transformed infrared spectroscopy, and magnetic susceptibility. The reactor temperature was decreased to 300 °C to investigate the early stages of the Reaction. Formation of crystalline LiFePO4 begins in the range 300-400 °C only if the polymer is used as the carbonaceous additive. This LiFePO4 Formation is made possible by the reduction of Fe(III) species by gases such as H2 or gaseous hydrocarbons evolved during the calcination of the polymer. Moreover, decomposition of the polymer results in a carbonaceous deposit on the surface of the LiFePO4 particles. An Li3Fe2(PO4)3 impurity found after sintering at 400 °C for 4 h was greatly reduced after sintering at 400 °C for 24 h, and phase- pure LiFePO4 was attained at 700 °C. Where the solid carbon powder was used as the reducing agent, no Fe(II) species could be detected after sintering at 400 °C. Carbothermal reduction of Fe(III) is ruled out in this temperature range.
Nathan W. Hudson - One of the best experts on this subject based on the ideXlab platform.
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Religion, repulsion, and Reaction Formation: Transforming repellent attractions and repulsions.
Journal of personality and social psychology, 2017Co-Authors: Dov Cohen, Emily Kim, Nathan W. HudsonAbstract:Protestants were more likely than non-Protestants to demonstrate phenomena consistent with the use of Reaction Formation. Lab experiments showed that when manipulations were designed to produce taboo attractions (to unconventional sexual practices), Protestants instead showed greater repulsion. When implicitly conditioned to produce taboo repulsions (to African Americans), Protestants instead showed greater attraction. Supportive evidence from other studies came from clinicians' judgments, defense mechanism inventories, and a survey of respondent attitudes. Other work showed that Protestants who diminished and displaced threatening affect were more likely to sublimate this affect into creative activities; the present work showed that Protestants who do not or cannot diminish or displace such threatening affect instead reverse it. Traditional individual difference variables showed little ability to predict Reaction Formation, suggesting that the observed processes go beyond what we normally study when we talk about self-control. (PsycINFO Database Record
C Julien - One of the best experts on this subject based on the ideXlab platform.
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Mechanism of the Fe3+ reduction at low temperature for LiFePO4 synthesis from a polymeric additive
Chemistry of Materials, 2007Co-Authors: N Ravet, Michel Gauthier, K Zaghib, John B Goodenough, Alain Mauger, Francois Gendron, C JulienAbstract:Comparison is made between the use of either a carbon powder or a polymer additive to the precursors in the synthesis of LiFePO4 from the Fe(III) compound FePO4(H2O)(2) and Li2CO3. The evolution of the structural properties and phase purity with temperature and time have been monitored at all length scales by X-ray diffraction, Fourier transformed infrared spectroscopy, and magnetic susceptibility. The reactor temperature was decreased to 300 degrees C to investigate the early stages of the Reaction. Formation of crystalline LiFePO4 begins in the range 300-400 degrees C only if the polymer is used as the carbonaceous additive. This LiFePO4 Formation is made possible by the reduction of Fe(III) species by gases such as H-2 or gaseous hydrocarbons evolved during the calcination of the polymer. Moreover, decomposition of the polymer results in a carbonaceous deposit on the surface of the LiFePO4 particles. An Li3Fe2(PO4)(3) impurity found after sintering at 400 degrees C for 4 h was greatly reduced after sintering at 400 degrees C for 24 h, and phase-pure LiFePO4 was attained at 700 degrees C. Where the solid carbon powder was used as the reducing agent, no Fe(II) species could be detected after sintering at 400 degrees C. Carbothermal reduction of Fe(III) is ruled out in this temperature range.
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mechanism of the fe3 reduction at low temperature for lifepo4 synthesis from a polymeric additive
Chemistry of Materials, 2007Co-Authors: N Ravet, Michel Gauthier, K Zaghib, John B Goodenough, Alain Mauger, Francois Gendron, C JulienAbstract:Comparison is made between the use of either a carbon powder or a polymer additive to the precursors in the synthesis of LiFePO4 from the Fe(III) compound FePO4(H2O)2 and Li2CO3. The evolution of the structural properties and phase purity with temperature and time have been monitored at all length scales by X-ray diffraction, Fourier transformed infrared spectroscopy, and magnetic susceptibility. The reactor temperature was decreased to 300 °C to investigate the early stages of the Reaction. Formation of crystalline LiFePO4 begins in the range 300−400 °C only if the polymer is used as the carbonaceous additive. This LiFePO4 Formation is made possible by the reduction of Fe(III) species by gases such as H2 or gaseous hydrocarbons evolved during the calcination of the polymer. Moreover, decomposition of the polymer results in a carbonaceous deposit on the surface of the LiFePO4 particles. An Li3Fe2(PO4)3 impurity found after sintering at 400 °C for 4 h was greatly reduced after sintering at 400 °C for 24 h,...
