Reliable production of biofuels and specifically bioethanol has attracted a significant amount of re-search recently.Within this context,this study deals with dynamic simulation of bioethanol production processes and ...Reliable production of biofuels and specifically bioethanol has attracted a significant amount of re-search recently.Within this context,this study deals with dynamic simulation of bioethanol production processes and in particular aims at developing a mathematical model for describing simultaneous saccharification and co-fermentation （SSCF） of C6 and C5 sugars.The model is constructed by combining existing mathematical mod-els for enzymatic hydrolysis and co-fermentation.An inhibition of ethanol on cellulose conversion is introduced in order to increase the reliability.The mathematical model for the SSCF is verified by comparing the model predic-tions with experimental data obtained from the ethanol production based on kraft paper mill sludge.When fitting the model to the data,only the yield coefficients for glucose and xylose metabolism were fine-tuned,which were found to be 0.43 g·g-1 （ethanol/glucose） and 0.35 g·g-1 （ethanol/xylose） respectively.These promising validation results encourage further model application to evaluate different process configurations for lignocellulosic bioetha-nol technology.展开更多
The solvent selection methodology developed earlier by. Gani （tal. （Comp. Chem. Eng., 2005）has been extended to handle multi-step reaction systems. The solvent selection problem was formulated based on the methodol...The solvent selection methodology developed earlier by. Gani （tal. （Comp. Chem. Eng., 2005）has been extended to handle multi-step reaction systems. The solvent selection problem was formulated based on the methodology guidelines, and solved using ICAS software tool. A list with solvent candidates is generated so that it can be further investigated experimentally. Comments and clarifications from chemists have been incorporated into the problem forrnulations to clarify the role of the solvents in the chemistry and potential reactivity issues. Highly promising results were obtained, in accordance with. industrial process data.展开更多
This paper assesses electoral participation and studies the determinants of such participation, focusing on presidential elections in Cote d＇Ivoire. We use a dataset on elections in Africa and a survey financed by th...This paper assesses electoral participation and studies the determinants of such participation, focusing on presidential elections in Cote d＇Ivoire. We use a dataset on elections in Africa and a survey financed by the European Commission and conducted by the Ivorian Center of Social and Economic Research （CIRES） in 2005. We find a decline in voter turnout since 1990 for both presidential and parliamentary elections. We also find that the probability of voting varies across ethnic groups and significantly increases with education levels, interest in politics, satisfaction with democracy and satisfaction with government but decreases with insecurity during elections. Moreover, we show that there is an inverted U-shaped relationship between age and the probability of voting. This probability is higher for men than women and for workers and retirees compared to unemployed, but it is low for students. Concerning the vote choice, we find that relative to the ＂program and party＂ criterion, the probability of choosing the candidate on the basis of his individual characteristics decreases with age, insecurity, satisfaction with democracy while it increases with satisfaction with government and with secondary, university or Koran education level.展开更多
基金Supported by the Mexican National Council for Science and Technology (CONACyT# 118903)the Danish Research Council for Technology and Production Sciences (FTP# 274-07-0339)
文摘Reliable production of biofuels and specifically bioethanol has attracted a significant amount of re-search recently.Within this context,this study deals with dynamic simulation of bioethanol production processes and in particular aims at developing a mathematical model for describing simultaneous saccharification and co-fermentation （SSCF） of C6 and C5 sugars.The model is constructed by combining existing mathematical mod-els for enzymatic hydrolysis and co-fermentation.An inhibition of ethanol on cellulose conversion is introduced in order to increase the reliability.The mathematical model for the SSCF is verified by comparing the model predic-tions with experimental data obtained from the ethanol production based on kraft paper mill sludge.When fitting the model to the data,only the yield coefficients for glucose and xylose metabolism were fine-tuned,which were found to be 0.43 g·g-1 （ethanol/glucose） and 0.35 g·g-1 （ethanol/xylose） respectively.These promising validation results encourage further model application to evaluate different process configurations for lignocellulosic bioetha-nol technology.
基金PRISM FP6 Marie Curie Research Training Network (MRTN-CT-2004-512233)
文摘The solvent selection methodology developed earlier by. Gani （tal. （Comp. Chem. Eng., 2005）has been extended to handle multi-step reaction systems. The solvent selection problem was formulated based on the methodology guidelines, and solved using ICAS software tool. A list with solvent candidates is generated so that it can be further investigated experimentally. Comments and clarifications from chemists have been incorporated into the problem forrnulations to clarify the role of the solvents in the chemistry and potential reactivity issues. Highly promising results were obtained, in accordance with. industrial process data.
文摘This paper assesses electoral participation and studies the determinants of such participation, focusing on presidential elections in Cote d＇Ivoire. We use a dataset on elections in Africa and a survey financed by the European Commission and conducted by the Ivorian Center of Social and Economic Research （CIRES） in 2005. We find a decline in voter turnout since 1990 for both presidential and parliamentary elections. We also find that the probability of voting varies across ethnic groups and significantly increases with education levels, interest in politics, satisfaction with democracy and satisfaction with government but decreases with insecurity during elections. Moreover, we show that there is an inverted U-shaped relationship between age and the probability of voting. This probability is higher for men than women and for workers and retirees compared to unemployed, but it is low for students. Concerning the vote choice, we find that relative to the ＂program and party＂ criterion, the probability of choosing the candidate on the basis of his individual characteristics decreases with age, insecurity, satisfaction with democracy while it increases with satisfaction with government and with secondary, university or Koran education level.
