In this work, a thermodynamic model is developed for prediction of structure H hydrate formation. The model combines the Peng-Robinson equation of state for the vapor, liquid and aqueous phases with the extended Ng-Ro...In this work, a thermodynamic model is developed for prediction of structure H hydrate formation. The model combines the Peng-Robinson equation of state for the vapor, liquid and aqueous phases with the extended Ng-Robinson hydrate model for gas hydrate formation of all three structures. The parameters of 14 structure- H hydrate formers are determined based on the experimental data of structure-H hydrates in the literature. The expression of fugacity of water in the empty hydrate phase is correlated for calculating structure-H hydrate formation conditions in the absence of free water. The model is tested by predicting hydrate formation conditions of a number of structure-H hydrate forming systems which are in good agreement with the experimental data. The proposed model is also applied to the prediction of hydrate formation conditions for various reservoir fluids such as natural gas and gas condensate.展开更多
This research serves the primary purpose to support the reform of administration budgets for Taiwan Residents universities to optimize their document processing system. The main research method applied is quantitative...This research serves the primary purpose to support the reform of administration budgets for Taiwan Residents universities to optimize their document processing system. The main research method applied is quantitative analysis to explore the relationships between document quantity and each administration spending. The research observes that Taiwan Residents universities in general rely more on electronic systems to manage documents. Therefore, as proven by correlation test and regression model, personnel spending and miscellaneous spending are the only two categories which can help predict document flows. However, only miscellaneous spending is positively related to document quantity, so this category should be allocated with more funding. Personnel spending, on the contrary, should be less. For the long-term budgeting strategy, Taiwan Residents universities should begin with discovering problems from the existing system, design an allocation plan, execute the plan, and finally evaluate the outcomes. This project is on the first to explore the new academic research field which relates to logistics, budgeting, and university administration.展开更多
This paper provides an overview of the state of art of reverse logistics and current status of waste management problems with special emphasis on developing countries. Logistics activities have been practiced and play...This paper provides an overview of the state of art of reverse logistics and current status of waste management problems with special emphasis on developing countries. Logistics activities have been practiced and played a fundamental role in the global economic development for over 5,000 years. It has then been transformed into different logistics branches and elaborates the emergency of reverse logistics as one of the most important. The paper presents the evolution of logistics into reverse logistics and how it relates to waste management both in the developed and developing world. Reverse logistics is a relatively new phenomenon in the research area which is mainly referring to damaged goods, the take back of products that should be returned to the manufacturers or distributors. Reverse logistics is relatively more practiced in an organized way in the developed world than in the developing countries in that the latter provided less value additions on reversed products.展开更多
Accurate physical and chemical properties of adsorbents are required for the efficient design of fixed bed adsorbers. The bed void and particle void are significant physical properties. One of the experimentally deter...Accurate physical and chemical properties of adsorbents are required for the efficient design of fixed bed adsorbers. The bed void and particle void are significant physical properties. One of the experimentally determination technique for the bed void is a breakthrough curve method. In the present paper, experimental conditions for determining the bed void from breakthrough curve were investigated because complex conditions are required. The values of bed void were determined from theoretical elution curve at the point of c/c0 = 0.5 under the condition of negligible amount adsorbed. The bed void value determined from elution curve was clearly affected by particle void and fluid velocity, and regarded as ＂apparent＂ bed void values. For large porosity particles, it was difficult to determine the true bed void value due to the effect of penetration into macro pores. Then, the bed void fraction can be determined safely from breakthrough curve when particles possessing small particle void are used.展开更多
Water plays a crucial role in the melting of Earth's mantle. Mantle magmatisms mostly occur at plate boundaries(including subduction zones and mid-ocean ridges) and in some intraplate regions with thermal anomaly....Water plays a crucial role in the melting of Earth's mantle. Mantle magmatisms mostly occur at plate boundaries(including subduction zones and mid-ocean ridges) and in some intraplate regions with thermal anomaly. At oceanic subduction zones, water released by the subducted slab may induce melting of the overlying mantle wedge or even the slab itself, giving rise to arc magmatism, or may evolve into a supercritical fluid. The physicochemical conditions for the formation of slab melt and supercritical fluid are still under debate. At mid-ocean ridges and intraplate hot zones, water and CO_2 cause melting of the upwelling mantle to occur at greater depths and in greater extents. Low degree melting of the mantle may occur at boundaries between Earth's internal spheres, including the lithosphere-asthenosphere boundary(LAB), the upper mantletransition zone boundary, and the transition zone-lower mantle boundary, usually attributed to contrasting water storage capacity across the boundary. The origin for the stimulating effect of water on melting lies in that water as an incompatible component has a strong tendency to be enriched in the melt(i.e., with a mineral-melt partition coefficient much smaller than unity), thereby lowering the Gibbs free energy of the melt. The partitioning of water between melt and mantle minerals such as olivine, pyroxenes and garnet has been investigated extensively, but the effects of hydration on the density and transport properties of silicate melts require further assessments by experimental and computational approaches.展开更多
基金Supported by the National Natural Science Foundation of China (No. 20490207, No. 20176028, No. 90210020) and Huo Ying-dong Education Foundation (No. 81064)
文摘In this work, a thermodynamic model is developed for prediction of structure H hydrate formation. The model combines the Peng-Robinson equation of state for the vapor, liquid and aqueous phases with the extended Ng-Robinson hydrate model for gas hydrate formation of all three structures. The parameters of 14 structure- H hydrate formers are determined based on the experimental data of structure-H hydrates in the literature. The expression of fugacity of water in the empty hydrate phase is correlated for calculating structure-H hydrate formation conditions in the absence of free water. The model is tested by predicting hydrate formation conditions of a number of structure-H hydrate forming systems which are in good agreement with the experimental data. The proposed model is also applied to the prediction of hydrate formation conditions for various reservoir fluids such as natural gas and gas condensate.
文摘This research serves the primary purpose to support the reform of administration budgets for Taiwan Residents universities to optimize their document processing system. The main research method applied is quantitative analysis to explore the relationships between document quantity and each administration spending. The research observes that Taiwan Residents universities in general rely more on electronic systems to manage documents. Therefore, as proven by correlation test and regression model, personnel spending and miscellaneous spending are the only two categories which can help predict document flows. However, only miscellaneous spending is positively related to document quantity, so this category should be allocated with more funding. Personnel spending, on the contrary, should be less. For the long-term budgeting strategy, Taiwan Residents universities should begin with discovering problems from the existing system, design an allocation plan, execute the plan, and finally evaluate the outcomes. This project is on the first to explore the new academic research field which relates to logistics, budgeting, and university administration.
文摘This paper provides an overview of the state of art of reverse logistics and current status of waste management problems with special emphasis on developing countries. Logistics activities have been practiced and played a fundamental role in the global economic development for over 5,000 years. It has then been transformed into different logistics branches and elaborates the emergency of reverse logistics as one of the most important. The paper presents the evolution of logistics into reverse logistics and how it relates to waste management both in the developed and developing world. Reverse logistics is a relatively new phenomenon in the research area which is mainly referring to damaged goods, the take back of products that should be returned to the manufacturers or distributors. Reverse logistics is relatively more practiced in an organized way in the developed world than in the developing countries in that the latter provided less value additions on reversed products.
文摘Accurate physical and chemical properties of adsorbents are required for the efficient design of fixed bed adsorbers. The bed void and particle void are significant physical properties. One of the experimentally determination technique for the bed void is a breakthrough curve method. In the present paper, experimental conditions for determining the bed void from breakthrough curve were investigated because complex conditions are required. The values of bed void were determined from theoretical elution curve at the point of c/c0 = 0.5 under the condition of negligible amount adsorbed. The bed void value determined from elution curve was clearly affected by particle void and fluid velocity, and regarded as ＂apparent＂ bed void values. For large porosity particles, it was difficult to determine the true bed void value due to the effect of penetration into macro pores. Then, the bed void fraction can be determined safely from breakthrough curve when particles possessing small particle void are used.
基金supported by the National Natural Science Foundation of China(Grant Nos.41590622&41473058)the 111 Project of Ministry of Education,China+1 种基金the Fundamental Research Funds for the Central Universities of Chinathe Recruitment Program of Global Experts(Thousand Talents),China
文摘Water plays a crucial role in the melting of Earth's mantle. Mantle magmatisms mostly occur at plate boundaries(including subduction zones and mid-ocean ridges) and in some intraplate regions with thermal anomaly. At oceanic subduction zones, water released by the subducted slab may induce melting of the overlying mantle wedge or even the slab itself, giving rise to arc magmatism, or may evolve into a supercritical fluid. The physicochemical conditions for the formation of slab melt and supercritical fluid are still under debate. At mid-ocean ridges and intraplate hot zones, water and CO_2 cause melting of the upwelling mantle to occur at greater depths and in greater extents. Low degree melting of the mantle may occur at boundaries between Earth's internal spheres, including the lithosphere-asthenosphere boundary(LAB), the upper mantletransition zone boundary, and the transition zone-lower mantle boundary, usually attributed to contrasting water storage capacity across the boundary. The origin for the stimulating effect of water on melting lies in that water as an incompatible component has a strong tendency to be enriched in the melt(i.e., with a mineral-melt partition coefficient much smaller than unity), thereby lowering the Gibbs free energy of the melt. The partitioning of water between melt and mantle minerals such as olivine, pyroxenes and garnet has been investigated extensively, but the effects of hydration on the density and transport properties of silicate melts require further assessments by experimental and computational approaches.
