The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Suryadi Ismadji - One of the best experts on this subject based on the ideXlab platform.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Alfin Kurniawan, A. C. Suwandi, X S Zhao, Suryadi IsmadjiAbstract:Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡ < 0. The activation energy (Ea) of transesterification, forward and reverse esterification reactions was 36.01 kJ/mol, 28.38 kJ/mol, and 5.66 kJ/mol, respectively.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Lu Ki Ong, A. C. Suwandi, Alfin Kurniawan, X S Zhao, Chun Xiang Lin, Suryadi IsmadjiAbstract:Abstract Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡
Alfin Kurniawan - One of the best experts on this subject based on the ideXlab platform.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Alfin Kurniawan, A. C. Suwandi, X S Zhao, Suryadi IsmadjiAbstract:Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡ < 0. The activation energy (Ea) of transesterification, forward and reverse esterification reactions was 36.01 kJ/mol, 28.38 kJ/mol, and 5.66 kJ/mol, respectively.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Lu Ki Ong, A. C. Suwandi, Alfin Kurniawan, X S Zhao, Chun Xiang Lin, Suryadi IsmadjiAbstract:Abstract Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡
A. C. Suwandi - One of the best experts on this subject based on the ideXlab platform.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Alfin Kurniawan, A. C. Suwandi, X S Zhao, Suryadi IsmadjiAbstract:Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡ < 0. The activation energy (Ea) of transesterification, forward and reverse esterification reactions was 36.01 kJ/mol, 28.38 kJ/mol, and 5.66 kJ/mol, respectively.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Lu Ki Ong, A. C. Suwandi, Alfin Kurniawan, X S Zhao, Chun Xiang Lin, Suryadi IsmadjiAbstract:Abstract Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡
X S Zhao - One of the best experts on this subject based on the ideXlab platform.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Alfin Kurniawan, A. C. Suwandi, X S Zhao, Suryadi IsmadjiAbstract:Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡ < 0. The activation energy (Ea) of transesterification, forward and reverse esterification reactions was 36.01 kJ/mol, 28.38 kJ/mol, and 5.66 kJ/mol, respectively.
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transesterification of leather tanning waste to biodiesel at supercritical condition kinetics and thermodynamics studies
Journal of Supercritical Fluids, 2013Co-Authors: Lu Ki Ong, A. C. Suwandi, Alfin Kurniawan, X S Zhao, Chun Xiang Lin, Suryadi IsmadjiAbstract:Abstract Catalyst-free transesterification of leather tanning waste with high free fatty acid (FFA) content at supercritical condition was reported in this work. The experiments were performed in batch system at various temperatures (250–325 °C) under constant pressure of 12 MPa and methanol/fatty oil molar ratio of 40:1 for reaction time of 2–10 min. Kinetic modeling of formation of fatty acid methyl esters (FAMEs) that incorporate reversible esterification and non-reversible transesterification simultaneously was verified. The proposed semi-empirical model was fitted against kinetic experimental data over temperature range studied. The kinetic parameters (i.e. k′TE, k′E, and kE′) were determined by nonlinear regression fitting. Thermodynamic activation parameters of the reactions were evaluated based on activation Complex Theory (ACT) and the following results are obtained: ΔG‡ > 0, ΔH‡ > 0, and ΔS‡
Kirk Broders - One of the best experts on this subject based on the ideXlab platform.
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emergence of white pine needle damage in the northeastern united states is associated with changes in pathogen pressure in response to climate change
Global Change Biology, 2017Co-Authors: Stephen A Wyka, Cheryl Smith, Isabel A Munck, Barrett N Rock, Beth Ziniti, Kirk BrodersAbstract:The defoliation of the eastern white pine (Pinus strobus) across the northeastern United States is an escalating concern threatening the ecological health of northern forests and economic vitality of the region's lumber industry. First documented in the spring of 2010 affecting 24 328 hectares in the state of Maine, white pine needle damage (WPND) has continued to spread and is now well established in all New England states. While causal agents of WPND are known, current research is lacking in both sampling distribution and the specific environmental factor(s) that affect the development and spread of this disease Complex. This study aims to construct a more detailed distribution map of the four primary causal agents within the region, as well as utilize long-term WPND monitoring plots and data collected from land-based weather stations to develop a climatic model to predict the severity of defoliation events in the proceeding year. Sampling results showed a greater distribution of WPND than previously reported. WPND was generally found in forest stands that compromised >50% eastern white pine by basal area. No single species, nor a specific combination of species had a dominating presence in particular states or regions, thus supporting the disease Complex Theory that WPND is neither caused by an individual species nor by a specific combination of species. In addition, regional weather data confirmed the trend of increasing temperature and precipitation observed in this region with the previous year's May, June, and July rainfall being the best predictor of defoliation events in the following year. Climatic models were developed to aid land managers in predicting disease severity and accordingly adjust their management decisions. Our results clearly demonstrate the role changing climate patterns have on the health of eastern white pine in the northeastern United States.