A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing c...A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing constraint priorities as propositional logics and by transforming the propositional logics into inequalities,the infeasibility and constraint prioritization issues are solved in the MPC. Constraints with higher priorities are met first, and then these with lower priorities are satisfied as much as possible. This new approach is illustrated in the control of a heavy oil fractionator-Shell column. The overall control performance has been significantly improved through the infeasibility and control priorities handling.展开更多
Recently, the desiccation effect of the North Atlantic Oscillation(NAO) is found to be positively correlated with violent conflict in pre-industrial Europe, with agricultural shrinkage and its subsequent economic shoc...Recently, the desiccation effect of the North Atlantic Oscillation(NAO) is found to be positively correlated with violent conflict in pre-industrial Europe, with agricultural shrinkage and its subsequent economic shocks to be their causal link. However, it remains unexplored whether the correlation persists if the study period is extended backward in time, a different definition of violent conflict is applied, or the relationship is examined at lower geographic levels. In this study, we based on 835 internal disturbance incidents in Europe during 1049–1800 to conduct long-temporal and multi-scalar examination on the NAO-conflict nexus. ′Time-series′ and ′panel data′ disaggregation approaches, together with Granger Causality, Multiple Regression, and Survival Analyses were applied to verify the nexus quantitatively. Results show that the positive NAO-conflict correlation was significant at the continent and physiographic zone levels. During the positive NAO phases, the annual probability of internal disturbance outbreak increased by 70.0% in the southern Europe and the Mediterranean, a zone most affected by the NAO-induced desiccation effect. Yet, the NAO-conflict correlation was rather inconsistent when it was downscaled to the sub-regional level. Moreover, the NAO-conflict correlation was inflated under the time-series approach, while the panel data approach demonstrated the region-specific nature of the NAO forcing more clearly. The associated implications in examining climate-conflict nexus are discussed. Our findings may be crucial in examining violent conflict in the northwestern Africa, a highly agricultural region affected by the NAO.展开更多
Three industrial spent S Zorb sorbents extracted from production line were studied with XRD, TPR-MS and XPS. The characterization results of XPS and TPR-MS identified the existence of amorphous Ni_xS_y on industrial s...Three industrial spent S Zorb sorbents extracted from production line were studied with XRD, TPR-MS and XPS. The characterization results of XPS and TPR-MS identified the existence of amorphous Ni_xS_y on industrial spent S Zorb sorbents, while the existing XRD quantitative analysis methods can only provide the long-range order in phase information and the grain size of Ni metal. XPS is a powerful tool to investigate the chemical states of nickel atom and the depthwise distribution of nickel species on S Zorb sorbent. Ni_xS_y and Ni metal species coexist on the industrial spent sorbents, and their percentages to total nickel slightly change with the operating conditions in the surface layer. It proves that Ni_xS_y is a stable intermediate product rather than a transition state. The information can contribute to the better elucidation of S Zorb desulfurization mechanism and offer a new direction for selectivity optimization of industrial S Zorb sorbents.展开更多
The large shift of surplus labor from agriculture to industry and services is seen in many countries around the world as well as in Vietnam in the process of industrialization and modernization of the country that has...The large shift of surplus labor from agriculture to industry and services is seen in many countries around the world as well as in Vietnam in the process of industrialization and modernization of the country that has set questions about the sustainability of rural surplus labor： is there still a source of surplus labor in rural areas？ If so, how large is the source of surplus labor and how long it can be lasting？ These questions were hotly debated in the literature abroad. But in Vietnam there is very little or hardly exchanged opinions about the concepts and methods of measurement of surplus labor in general and surplus labor in agriculture in particular. This article refers to the measurement approach of surplus labor in agriculture in Vietnam.展开更多
The liquid effluents released from several industries including the pulp and paper industries contain phenol and phenolic compounds. The hazardous phenols and their chlorinated phenolic derivatives from pulp and paper...The liquid effluents released from several industries including the pulp and paper industries contain phenol and phenolic compounds. The hazardous phenols and their chlorinated phenolic derivatives from pulp and paper industries bear the potential to exert deleterious effects on the human health and aquatic ecosystems, if they are released untreated in the environment. Biodegradation of phenolic compounds in the effluent streams from pulp and paper industries is an important eco-friendly method for the removal of toxicity in industrial waste water, while the minimization of formation of these toxic compounds require several in-plant biotechnological techniques such as biopulping and biobleaching. Present paper reviews, the biochemical pathways involved in degradation of phenols and chlorophenols through microorganisms. Various biotechnological strategies involved in minimization and biodegradation of phenol and phenolic compounds and their related environmental engineering aspects such as utility of different bioreactor configurations have been discussed for the treatment of pulp and paper mill effluents.展开更多
基金Supported by the 973 Program (No. 2002CB312200)National High Tech. Project of China (863/CIMS 2004AA412050).
文摘A hybrid approach using MLD (mixed logical dynamical) framework to handle infeasibility and constraint prioritization issues in MPC (model predictive control) based on input-output model is introduced. By expressing constraint priorities as propositional logics and by transforming the propositional logics into inequalities,the infeasibility and constraint prioritization issues are solved in the MPC. Constraints with higher priorities are met first, and then these with lower priorities are satisfied as much as possible. This new approach is illustrated in the control of a heavy oil fractionator-Shell column. The overall control performance has been significantly improved through the infeasibility and control priorities handling.
基金Under the auspices of Hui Oi-Chow Trust Fund(No.201302172003,201502172003)Research Grants Council of Government of Hong Kong Special Administrative Region of China(No.HKU758712H,HKU745113H,HKU17610715)
文摘Recently, the desiccation effect of the North Atlantic Oscillation(NAO) is found to be positively correlated with violent conflict in pre-industrial Europe, with agricultural shrinkage and its subsequent economic shocks to be their causal link. However, it remains unexplored whether the correlation persists if the study period is extended backward in time, a different definition of violent conflict is applied, or the relationship is examined at lower geographic levels. In this study, we based on 835 internal disturbance incidents in Europe during 1049–1800 to conduct long-temporal and multi-scalar examination on the NAO-conflict nexus. ′Time-series′ and ′panel data′ disaggregation approaches, together with Granger Causality, Multiple Regression, and Survival Analyses were applied to verify the nexus quantitatively. Results show that the positive NAO-conflict correlation was significant at the continent and physiographic zone levels. During the positive NAO phases, the annual probability of internal disturbance outbreak increased by 70.0% in the southern Europe and the Mediterranean, a zone most affected by the NAO-induced desiccation effect. Yet, the NAO-conflict correlation was rather inconsistent when it was downscaled to the sub-regional level. Moreover, the NAO-conflict correlation was inflated under the time-series approach, while the panel data approach demonstrated the region-specific nature of the NAO forcing more clearly. The associated implications in examining climate-conflict nexus are discussed. Our findings may be crucial in examining violent conflict in the northwestern Africa, a highly agricultural region affected by the NAO.
基金the funding of the project by SINOPEC(No.114138)
文摘Three industrial spent S Zorb sorbents extracted from production line were studied with XRD, TPR-MS and XPS. The characterization results of XPS and TPR-MS identified the existence of amorphous Ni_xS_y on industrial spent S Zorb sorbents, while the existing XRD quantitative analysis methods can only provide the long-range order in phase information and the grain size of Ni metal. XPS is a powerful tool to investigate the chemical states of nickel atom and the depthwise distribution of nickel species on S Zorb sorbent. Ni_xS_y and Ni metal species coexist on the industrial spent sorbents, and their percentages to total nickel slightly change with the operating conditions in the surface layer. It proves that Ni_xS_y is a stable intermediate product rather than a transition state. The information can contribute to the better elucidation of S Zorb desulfurization mechanism and offer a new direction for selectivity optimization of industrial S Zorb sorbents.
文摘The large shift of surplus labor from agriculture to industry and services is seen in many countries around the world as well as in Vietnam in the process of industrialization and modernization of the country that has set questions about the sustainability of rural surplus labor： is there still a source of surplus labor in rural areas？ If so, how large is the source of surplus labor and how long it can be lasting？ These questions were hotly debated in the literature abroad. But in Vietnam there is very little or hardly exchanged opinions about the concepts and methods of measurement of surplus labor in general and surplus labor in agriculture in particular. This article refers to the measurement approach of surplus labor in agriculture in Vietnam.
文摘The liquid effluents released from several industries including the pulp and paper industries contain phenol and phenolic compounds. The hazardous phenols and their chlorinated phenolic derivatives from pulp and paper industries bear the potential to exert deleterious effects on the human health and aquatic ecosystems, if they are released untreated in the environment. Biodegradation of phenolic compounds in the effluent streams from pulp and paper industries is an important eco-friendly method for the removal of toxicity in industrial waste water, while the minimization of formation of these toxic compounds require several in-plant biotechnological techniques such as biopulping and biobleaching. Present paper reviews, the biochemical pathways involved in degradation of phenols and chlorophenols through microorganisms. Various biotechnological strategies involved in minimization and biodegradation of phenol and phenolic compounds and their related environmental engineering aspects such as utility of different bioreactor configurations have been discussed for the treatment of pulp and paper mill effluents.
