A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services an...A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services and classified forest management, we hypothesized that the ecological-forest provides ecological services, whereas commercial-forest supplies wood and timber production, and the influences of the growth of population, social-economic development target, forest management methods and the technology changes on forest resources were also taken into account. The prediction reveals that the demand of total forestland of China will be 244.8, 261.2 and 362.2 million ha by the year 2010, 2020 and 2050, respectively. The results demonstrated that China will be confronted with a shortage of forest resources, especially with lack of ecological-oriented forests, in the future. It is suggested that sustainable management of forest resources must be reinforced and more attention should be drown no enhancing the service function of forest ecosystem.展开更多
Basing on the advanced foreign management theory and methods, introducing MRP-Ⅱ having DSS function and combining Chinese conditions, we present in this paper a method of embedding the block of “lot size” producti...Basing on the advanced foreign management theory and methods, introducing MRP-Ⅱ having DSS function and combining Chinese conditions, we present in this paper a method of embedding the block of “lot size” production in MRP-Ⅱ.展开更多
This paper analyzes the introduction of environmental taxes in the EU and Netherlands and their effects on agriculture, with a special focus on the background of the introduction of environmental tax systems, their de...This paper analyzes the introduction of environmental taxes in the EU and Netherlands and their effects on agriculture, with a special focus on the background of the introduction of environmental tax systems, their design concepts and effects on agriculture, the effects of fertilizer taxes in promoting sustainable agriculture, policy packages between environmental tax and environmental agreements, effects on globalization and global competitiveness, and conversion to renewable energy based on biomass resources.展开更多
Natural landscapes provide ability to live of local people. Because of the lack of information about the rent streams which are created in non-wood resources usage sphere, the priority of the state policy is given to ...Natural landscapes provide ability to live of local people. Because of the lack of information about the rent streams which are created in non-wood resources usage sphere, the priority of the state policy is given to the wood crude product. The purpose of this article is to explain why the ecology-economic accounting of wildlife resources is needed. Methodological approaches of the environment resources by the United Nations allow to define the rent streams created in sector of private households. Based on full economic value of non-wood resources the measurement of rent flows will allow to carry out updating of a state policy and to develop the mechanism of natural landscapes preservation and to increase socially-ecological efficiency of it＇s using.展开更多
The developing world still largely depends on biomass, such as wood, animal dung and agricultural waste for domestic fuel sources that are typically burned in traditional stoves. Ethiopia has different biomass resourc...The developing world still largely depends on biomass, such as wood, animal dung and agricultural waste for domestic fuel sources that are typically burned in traditional stoves. Ethiopia has different biomass resource for biochar production, through pyrolysis cook stove co-producing biochar. Coffee husks are the major solid residues from the handling and processing of coffee in the study area. This study was to evaluate the biochar co-producing pyrolysis cook stove with respect to heat transfer through the bed and biochar yield. From allothermal type of pyrolysis cook stove, the stove design was selected for both the computational fluid dynamic （CFD） simulation and experimental measurements. ANSYS 14.5 was used for CFD simulation of the wood combustion. The production of biochar from coffee husk, corncob and sawdust at different heating times, bed and stove surface temperature were undertaken. Bulk density, pH and surface area of the biochar were measured. While good agreement between simulation and experimental result was obtained in the conduction phase during pyrolysis, deviation between the two on account of the effect of volatile gas in changing the temperature trend within the biomass bed was noticed. Within the biomass type, the maximum mean biochar yield （38.91%） was seen from coffee husk. In the case of different stove designs, the minimum mean biochar yield （27.11%） was found from normal Anila stove. The pH of biochar is found to be significantly affected by the type of biomass （9.83 mean for corncob and coffee husk, 6.43 mean for sawdust）, heating time （9.19 mean for 90 min and 8.01 mean for 30 min） and stove type （9.52 mean for normal Anila and 8.01 mean for flangeless Anila continuous feeding type）. In fact, the type of biomass is observed to significantly affect the bulk density and surface area ofbiochar.展开更多
The chemical industry is nowadays predominantly using fossil raw materials,but the alternative use of bio-based resources is investigated to account for the foreseeable scarcity of fossil feedstocks.A main challenge o...The chemical industry is nowadays predominantly using fossil raw materials,but the alternative use of bio-based resources is investigated to account for the foreseeable scarcity of fossil feedstocks.A main challenge of using biobased feedstocks is the complexity of the impurity profile.For an economic production of bio-based chemicals,the use of intensified processes is inevitable and approaches are needed for the various process intensification techniques to identify their applicability to be used for the production of bio-based components.In the presented study,an approach is shown for the reactive distillation(RD) technology to identify the most critical bio-based impurities and their impact on the reactive distillation process.The investigated case-study is the production of n-butyl acrylate from acrylic acid and n-butanol.Among all initially identified impurities,the key impurities,having the biggest impact on the product purity in the reactive distillation process,are found.These impurities are then studied in more detail and an operating window depending on the impurity concentration is identified for the reactive distillation column.Furthermore,an integrated design of upstream and downstream processes is facilitated,as the presented results can be used in the development of the fermentation processes for the production of the bio-based reactants by decreasing the concentration of the critical impurities.展开更多
Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be util...Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.展开更多
This study was carried out to assess the growth characteristics of Grewia moll＆, Grewia tenax and Grewia villosa under the nursery and field conditions. Two experiments were conducted at the farm of the College of Na...This study was carried out to assess the growth characteristics of Grewia moll＆, Grewia tenax and Grewia villosa under the nursery and field conditions. Two experiments were conducted at the farm of the College of Natural Resources and Environmental Studies, University of Juba, Khartoum, Sudan. Randomized complete block design with three replications was used. Morphological and physiological factors were measured. Seedlings height, number of leaves, number of branches and sub-branches were different （P 〈 0.05） among the three species at the nursery stage and under field conditions. Collar diameter showed significant difference among the species under field conditions. Physiological factors exhibited more significant variations in the field than at the nursery stage. Variations in growth characteristics were attributed to genetics differences and different growth habit, while variations in physiological factors （photosynthesis and transpiration rate） were attributed to differences in leaf structure, size and number of stomatal pores.展开更多
This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to d...This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to determine whether the boiler can be retrofitted for the fulfilment of the prospective environmental protection regulations relating to levels of NO_X emissions. The improvement of the air staging via the dual-fuel technique was based on the indirect co-firing technology. The impact of two arrangements of dedicated syngas nozzles(below and above the existing coal burners), two syngas compositions and two heat replacements(5% and 15%) on the course of thermal processes in a furnace was tested. The reductions in NO_X emissions were predicted relative to the baseline when only coal is combusted. The highest reduction of about 38% was achieved with the syngas nozzles below the existing coal burners and 15% heat replacement. This arrangement of nozzles offers the residence time sufficient to co-fire coal with waste derived syngas. A lower reduction in NO_X emissions was obtained with the nozzles above the burners as the enlargement of local fuel rich zone near syngas injection becomes significant for 15% heat replacement. Results provide for the decreasing impact of methane content along with the increase of syngas heat input. The avoided CO_2 emissions through the syngas indirect co-firing with coal in the boiler are linear function of heat replacements.展开更多
Knowledge Sharing and Service is one effective way to eliminate knowledge poverty and promote social development.Existing knowledge sharing and service is mainly provided in some organizations or specific social group...Knowledge Sharing and Service is one effective way to eliminate knowledge poverty and promote social development.Existing knowledge sharing and service is mainly provided in some organizations or specific social groups.Besides,a knowledge sharing and service system about geography,natural resources and ecology has not been reported.We proposed a public welfare professional knowledge-sharing and service platform for all members of society in geography,natural resources and ecology.The construction of a knowledge-sharing and service platform is based on five aspects of work：analysis of user requirements,setting standards and drafting policies,aggregating knowledge resources,the technical realization and the maintenance of service.Knowledge resources can be aggregated by using a＂two-step＂strategy.A knowledge-sharing and service system can be implemented by using＂four-tier＂structures that are comprised of resources,resource access,application and service,based on the Hadoop-distributed cluster architecture.It has been proven that adhering to the idea of co-building and co-sharing,and using the mechanism of＂payment is equal to benefit＂can effectively promote the gathering of knowledge resources,and arouse the enthusiasm of all members of society to participate in knowledge sharing and service,to achieve the objective of narrowing the knowledge gap between social groups.展开更多
基金the National Key Technologies R&D Program of China (2006BAD03A09)the National Science Fund of China (40841001)
文摘A new model was developed to predict forestland demand of China during the years of 2010-2050 in terms of the concept of forest ecosystem services. On the basis of the relationship between forest ecosystem services and classified forest management, we hypothesized that the ecological-forest provides ecological services, whereas commercial-forest supplies wood and timber production, and the influences of the growth of population, social-economic development target, forest management methods and the technology changes on forest resources were also taken into account. The prediction reveals that the demand of total forestland of China will be 244.8, 261.2 and 362.2 million ha by the year 2010, 2020 and 2050, respectively. The results demonstrated that China will be confronted with a shortage of forest resources, especially with lack of ecological-oriented forests, in the future. It is suggested that sustainable management of forest resources must be reinforced and more attention should be drown no enhancing the service function of forest ecosystem.
文摘Basing on the advanced foreign management theory and methods, introducing MRP-Ⅱ having DSS function and combining Chinese conditions, we present in this paper a method of embedding the block of “lot size” production in MRP-Ⅱ.
文摘This paper analyzes the introduction of environmental taxes in the EU and Netherlands and their effects on agriculture, with a special focus on the background of the introduction of environmental tax systems, their design concepts and effects on agriculture, the effects of fertilizer taxes in promoting sustainable agriculture, policy packages between environmental tax and environmental agreements, effects on globalization and global competitiveness, and conversion to renewable energy based on biomass resources.
文摘Natural landscapes provide ability to live of local people. Because of the lack of information about the rent streams which are created in non-wood resources usage sphere, the priority of the state policy is given to the wood crude product. The purpose of this article is to explain why the ecology-economic accounting of wildlife resources is needed. Methodological approaches of the environment resources by the United Nations allow to define the rent streams created in sector of private households. Based on full economic value of non-wood resources the measurement of rent flows will allow to carry out updating of a state policy and to develop the mechanism of natural landscapes preservation and to increase socially-ecological efficiency of it＇s using.
文摘The developing world still largely depends on biomass, such as wood, animal dung and agricultural waste for domestic fuel sources that are typically burned in traditional stoves. Ethiopia has different biomass resource for biochar production, through pyrolysis cook stove co-producing biochar. Coffee husks are the major solid residues from the handling and processing of coffee in the study area. This study was to evaluate the biochar co-producing pyrolysis cook stove with respect to heat transfer through the bed and biochar yield. From allothermal type of pyrolysis cook stove, the stove design was selected for both the computational fluid dynamic （CFD） simulation and experimental measurements. ANSYS 14.5 was used for CFD simulation of the wood combustion. The production of biochar from coffee husk, corncob and sawdust at different heating times, bed and stove surface temperature were undertaken. Bulk density, pH and surface area of the biochar were measured. While good agreement between simulation and experimental result was obtained in the conduction phase during pyrolysis, deviation between the two on account of the effect of volatile gas in changing the temperature trend within the biomass bed was noticed. Within the biomass type, the maximum mean biochar yield （38.91%） was seen from coffee husk. In the case of different stove designs, the minimum mean biochar yield （27.11%） was found from normal Anila stove. The pH of biochar is found to be significantly affected by the type of biomass （9.83 mean for corncob and coffee husk, 6.43 mean for sawdust）, heating time （9.19 mean for 90 min and 8.01 mean for 30 min） and stove type （9.52 mean for normal Anila and 8.01 mean for flangeless Anila continuous feeding type）. In fact, the type of biomass is observed to significantly affect the bulk density and surface area ofbiochar.
基金funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no.241718,Eurobioref
文摘The chemical industry is nowadays predominantly using fossil raw materials,but the alternative use of bio-based resources is investigated to account for the foreseeable scarcity of fossil feedstocks.A main challenge of using biobased feedstocks is the complexity of the impurity profile.For an economic production of bio-based chemicals,the use of intensified processes is inevitable and approaches are needed for the various process intensification techniques to identify their applicability to be used for the production of bio-based components.In the presented study,an approach is shown for the reactive distillation(RD) technology to identify the most critical bio-based impurities and their impact on the reactive distillation process.The investigated case-study is the production of n-butyl acrylate from acrylic acid and n-butanol.Among all initially identified impurities,the key impurities,having the biggest impact on the product purity in the reactive distillation process,are found.These impurities are then studied in more detail and an operating window depending on the impurity concentration is identified for the reactive distillation column.Furthermore,an integrated design of upstream and downstream processes is facilitated,as the presented results can be used in the development of the fermentation processes for the production of the bio-based reactants by decreasing the concentration of the critical impurities.
文摘Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.
文摘This study was carried out to assess the growth characteristics of Grewia moll＆, Grewia tenax and Grewia villosa under the nursery and field conditions. Two experiments were conducted at the farm of the College of Natural Resources and Environmental Studies, University of Juba, Khartoum, Sudan. Randomized complete block design with three replications was used. Morphological and physiological factors were measured. Seedlings height, number of leaves, number of branches and sub-branches were different （P 〈 0.05） among the three species at the nursery stage and under field conditions. Collar diameter showed significant difference among the species under field conditions. Physiological factors exhibited more significant variations in the field than at the nursery stage. Variations in growth characteristics were attributed to genetics differences and different growth habit, while variations in physiological factors （photosynthesis and transpiration rate） were attributed to differences in leaf structure, size and number of stomatal pores.
基金carried out in the framework of 3190/23/P and S/WZ/1/2015 works financed by Ministry of Science and Higher Education of Poland from the funds for science
文摘This study focuses on a CFD modelling of biomass-derived syngas co-firing with coal in an older mid-sized PC-fired boiler of type OP-230 with low-emission burners on the front wall. The simulations were performed to determine whether the boiler can be retrofitted for the fulfilment of the prospective environmental protection regulations relating to levels of NO_X emissions. The improvement of the air staging via the dual-fuel technique was based on the indirect co-firing technology. The impact of two arrangements of dedicated syngas nozzles(below and above the existing coal burners), two syngas compositions and two heat replacements(5% and 15%) on the course of thermal processes in a furnace was tested. The reductions in NO_X emissions were predicted relative to the baseline when only coal is combusted. The highest reduction of about 38% was achieved with the syngas nozzles below the existing coal burners and 15% heat replacement. This arrangement of nozzles offers the residence time sufficient to co-fire coal with waste derived syngas. A lower reduction in NO_X emissions was obtained with the nozzles above the burners as the enlargement of local fuel rich zone near syngas injection becomes significant for 15% heat replacement. Results provide for the decreasing impact of methane content along with the increase of syngas heat input. The avoided CO_2 emissions through the syngas indirect co-firing with coal in the boiler are linear function of heat replacements.
基金Branch Center Project of Geography,Resources,and Ecology of Knowledge Center for Chinese Engineering Sciences and Technology(CKCEST-2017-1-8)the National Earth System Science Data Sharing Infrastructure(2005DKA32300)
文摘Knowledge Sharing and Service is one effective way to eliminate knowledge poverty and promote social development.Existing knowledge sharing and service is mainly provided in some organizations or specific social groups.Besides,a knowledge sharing and service system about geography,natural resources and ecology has not been reported.We proposed a public welfare professional knowledge-sharing and service platform for all members of society in geography,natural resources and ecology.The construction of a knowledge-sharing and service platform is based on five aspects of work：analysis of user requirements,setting standards and drafting policies,aggregating knowledge resources,the technical realization and the maintenance of service.Knowledge resources can be aggregated by using a＂two-step＂strategy.A knowledge-sharing and service system can be implemented by using＂four-tier＂structures that are comprised of resources,resource access,application and service,based on the Hadoop-distributed cluster architecture.It has been proven that adhering to the idea of co-building and co-sharing,and using the mechanism of＂payment is equal to benefit＂can effectively promote the gathering of knowledge resources,and arouse the enthusiasm of all members of society to participate in knowledge sharing and service,to achieve the objective of narrowing the knowledge gap between social groups.
