This paper introduces the energy consumption status in China, elaborate the affects of the unreasonable energy consumption structure on energy environment and sustainable development of economy. Simultaneously, it poi...This paper introduces the energy consumption status in China, elaborate the affects of the unreasonable energy consumption structure on energy environment and sustainable development of economy. Simultaneously, it points out the solution, i.e., to implement integrated resources planning (IRP)/demand side management (DSM), and gives some recommendations on the way of implementing IRP/DSM.展开更多
Proxy signatures have been used to enable the transfer of digital signing power within some context and ring signatures can be used to provide the anonymity of a signer. By combining the functionalities of proxy signa...Proxy signatures have been used to enable the transfer of digital signing power within some context and ring signatures can be used to provide the anonymity of a signer. By combining the functionalities of proxy signatures and ring signatures, this paper introduces a new concept, named ring proxy signature, which is a proxy signature generated by an anonymous member from a set of potential signers. The paper also constructs the first concrete ring proxy signature scheme based on the provably secure Schnorr's signatures and two ID-based ring proxy signature schemes. The security analysis is provided as well.展开更多
In the last years, there has been a big development of European policies and regulations on energy saving topics. This is due to the will to reach the targets of 20-20-20. Buildings consume a lot of energy, so the leg...In the last years, there has been a big development of European policies and regulations on energy saving topics. This is due to the will to reach the targets of 20-20-20. Buildings consume a lot of energy, so the legal framework related to the reduction of energy consumption in this sector has had a huge evolution. The "NZEB (nearly zero energy building)" concept was introduced in 2010, eight years after the release of the original EPBD (energy performance of buildings directive). By 2020, all new buildings and buildings that are subject to renovation should have very low energy consumption, covered for the major part by renewable sources. Designing and realizing this kind of building is a very ambitious task, which needs to be supported by appropriate tools and software. This paper presents a new tool for assessing building performance, named BENIMPACT Suite (building's environmental impact evaluator and optimizer), which is developed by EnginSoft (Italy). The suite is organized in different core modules that allow to verify how the building performance level is influenced by different design choices, such as envelope shape and materials, plant systems, renewable sources use, etc.. One of the test cases used to validate the BENIMPACT Suite energy performance is the evaluation of an interesting Italian ZEB, finished in 2010 and called CasaZeroEnergy. It is located in Felettano (Udine), a small town in northeastern Italy. This building is an experimental house designed and monitored by the Laboratory of Building Design of the University of Trento (Italy) and built by Polo Le Ville Plus Group (Cassacco-ltaly). The energy performance of this building was modelled and evaluated using BENIMPACT Suite, and simulation results were compared with monitored data.展开更多
The aim of this paper is to develop a simple EV model and predict its energy consumption with a variable and fixed ratio gearbox over a standard driving cycle in order to understand whether this could offer significan...The aim of this paper is to develop a simple EV model and predict its energy consumption with a variable and fixed ratio gearbox over a standard driving cycle in order to understand whether this could offer significant efficiency gains. The powertrain of a generic electric vehicle was modelled in Matlab / Simulink using the QSS Toolkit. The electric vehicle was then fitted with different transmissions with different levels of complexity. Simulations were done to investigate the energy consumptions across 6 standard driving cycles. The emerging conclusions are that it is possible to improve overall energy consumption levels by around 5 to 12 % with a variable ratio gearbox depending on the driving cycle used. However, there are many other practical considerations which must be weighed against this positive result - and the paper discusses the impact of several of these such as, gearbox efficiency, additional weight, cost and complexity, effect on drivability and potential for motor downsizing.展开更多
With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were s...With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were studied through collection of verified data in site visits and field tests.The result revealed that,electricity accounted for 99.79% of the total energy consumption,natural gas 0.17%,and diesel 0.04%.The air conditioning dominated the energy use with a share of 43.18%,equipment in the particular areas 26.90%,equipment in the office rooms 11.95%,lighting system 8.67%,general service system 7.57%,and miscellaneous items 1.73%.Statistical method including six indicators obtained the energy consumption benchmark with upper limit of 98.31 kW-h/m2 and lower limit of 55.26 kW-h/m2.According to ASHRAE standard(comfortable standard) and GB/T 18883-2002(acceptable standard),the indoor environmental quality of 51 sampled office buildings was classified into three ranks:good,normal and bad.With benchmark of building energy consumption combined with indoor environmental quality,it was found that only 3.92% of sampled buildings can be identified as the best performance buildings with low energy consumption and advanced indoor environmental quality,and the buildings classified into normal level accounted for the maximum ratio.展开更多
Residential energy consumption is varying considerably worldwide. In order to understand these variations, and thus design effective policies for energy reductions, one needs a better understanding of the different dr...Residential energy consumption is varying considerably worldwide. In order to understand these variations, and thus design effective policies for energy reductions, one needs a better understanding of the different drivers behind these variations. A comparison of geographical areas with similar climate and socio-economic conditions has shown significant variations in residential energy consumption across otherwise comparable case studies. This research paper aims to identify cultural and historical parameters that contribute to these significant variations, including economic, environmental and social traditions related to local availability of natural resources. Furthermore, the transferability of these parameters is evaluated, taking into consideration local legislation and planning documents, and historic and socio-economic accessibility of resources. It is evaluated to which degree these parameters can be transferred and included into building assessment tools and policy documents for planning and transformation of sustainable urban neighborhoods.展开更多
Electrical energy consumption is growing and is necessary to improve the technologies related to energy production. We have carried out a pilot study about environmental impacts during the manufacturing process of PV ...Electrical energy consumption is growing and is necessary to improve the technologies related to energy production. We have carried out a pilot study about environmental impacts during the manufacturing process of PV (photovoltaic) modules and compared between the energy requirement for the production of PV cells and modules and generation throughout the life time of the finished good that is PV module. It was taken into account the generation of environmental aspects and impacts in the manufacture of monocrystalline silicon PV modules (consisting of three components: silicon cell, fiat tempered glass and aluminum frame), and an analysis of a grid-connected PV system using an energetic alternative in residences was considered. Results show that, this kind of renewable energy is really clean and can be considered as a way to change the energy technology.展开更多
Located in the cold and very cold semiarid steppe climate zone, North Dakota boasts not only long cold winters but also hot summers, which significantly increases the energy consumption of buildings. In fact, North Da...Located in the cold and very cold semiarid steppe climate zone, North Dakota boasts not only long cold winters but also hot summers, which significantly increases the energy consumption of buildings. In fact, North Dakota has the highest energy consumption per capita in residential buildings (101 MM Btu in 2013), and its energy consumption per capita in commercial buildings ranks the second (l 18 MM Btu in 2013) in the nation. When humans spend a long time indoors to escape the inclement weather, their health will be more susceptible to the indoor environment. In addition, North Dakota has the 3rd least number of green buildings certified by LEED (Leadership in Energy and Environmental Design) in the nation. This paper aims to investigate the status quo of buildings with respect to energy, health and sustainability in North Dakota, and attempts to propose strategies regarding research and higher education to rectify the current issues. These strategies include but not limited to forming the architectural engineering program, a comprehensive and interdisciplinary program in buildings.展开更多
Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for ...Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem.展开更多
Athens, a metropolis characterized by agglutination and compactness, but at the same time facing numerous urban and transport issues, saw its population swell during the 20th century which led to extensive urbanizatio...Athens, a metropolis characterized by agglutination and compactness, but at the same time facing numerous urban and transport issues, saw its population swell during the 20th century which led to extensive urbanization phenomena. This continued urbanization increases profoundly all urban activities with transportation being the key driver in energy consumption. Theories for sustainable cities prerequisite are the integration of a number of acts in order to reduce energy consumption, with mobility being the first consideration among others. The aim of this paper is to critically explore implemented policies and plans as well as forthcoming strategic plans in terms of sustainable mobility as imposed in large scale regeneration plans in contemporary Athens. Research focuses on strategic interventions since the 1980s, such as the Athenian Daktylios (ring road for circulation management) and its later adjustments, the upcoming pedestrianization and unification of the commercial triangle and its subsequent tram line extension as well as the notable implementation of the metropolitan cycling network. Moreover, the discussion takes into consideration the implications of the Greek economic crisis in mobility choices, as aimless travels have been reduced to a minimum, several cars have been abandoned and cyclists seem to tentatively claim some space in the urban environment. What will likely be the next day in the Athenian historic centre? Considering the transformations that are expected in the immediate future, this research paper explores their potential to enhance urban environment, reduce climate change impacts and amplify resilience.展开更多
Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advance...Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advances necessitates a change and evolution in building envelopes. Controlling the energy consumption of the buildings is mostly through controlling the energy performance of the building envelopes. New technologies lead to the intelligent facades and envelopes. The envelope can be designed to be a part of the whole building's metabolism (energy production, storage and consumption) and morphology. The envelope would be a controlled part of the building which is managed through the central control system of the building, which connects it to other parts. It caused building envelope design to be changed fundamentally, so that there is a need to interact with engineering disciplines including computer engineering, mechanical engineering, material engineering and so on. All of these caused building envelope to get closer to biological and living systems. The physical restrictions which affect buildings system and living systems are the same. So they cause the same forces to shape the structure and form of the systems and the same rules to interact with the environment. The restrictions of material and energy resources caused living systems to be energy efficient and consuming less material. But the most important difference between living systems and building systems is in maximum use of different resources. As living systems use information maximally, the building system technology is based on using maximum energy. Now, there are many reasons and restrictions that building envelopes cannot act like living systems. But technological developments and contributing more disciplines in design and construction of building envelopes caused the future way of these envelopes get close to living systems for their energy efficiency. Some of living systems characteristics which the future building envelopes would have partially or benefit for the design process or construction are self-organization, evolution principles, hierarchical levels, processing energy, reaction to environmental stimuli and self-adjustment. Self-organization is achieved in some design software and in building material production for creating formal patterns. Evolution principles provide infrastructure for soft wares for optimization purposes and form creation. Hierarchical levels refer to giving hierarchical structure to the building envelopes through layering and designing different scales. Processing energy (metabolism) would be achieved through photovoltaic and solar collectors to produce energy and in passive systems for energy storage and distribution. Controlling solar radiation absorption and transmittance would help energy transfer from outside to building and vice versa. Reaction to environmental stimuli which is one of the most important characteristics of future building envelopes would use different types of active and passive sensors to create envelope mechanical reactions through material properties or collect data for processing in the control center to determine the right reaction. The reaction would be through different strategies such as changing properties and moving. Reaction could be passive or active. Self-adjustment can be achieved by control systems and processing units. All of these mean intelligent envelopes are essential parts of future buildings. Though it is now started with new design soft wares based on biological principles to optimize different parameters affecting the envelope function or to create the most efficient form.展开更多
This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only...This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.展开更多
The aim of this paper is to present the preliminary experimental analysis results carried out on the commercial internal combustion engine set in a CHP (combined heat and power) mode, fueled by renewable hydrogen an...The aim of this paper is to present the preliminary experimental analysis results carried out on the commercial internal combustion engine set in a CHP (combined heat and power) mode, fueled by renewable hydrogen and methane mixtures. The hydrogen is produced by an alkaline electrolyser fed by a 5.8 kWp grid connected PV (photovoltaic) plant. The acceptance test conducted with hydrogen percentages ranging from 0%-10% has been carried out at partial load: 45 kW^l instead of the full power of 60 kWe~. In order to evaluate the CHP energy consumption and environmental performance (NOx and CO), the analysis was conducted for 240 h, using a portable flue gas analyser and two mass flow meters for hydrogen and methane. Without engine parameters optimization--relative equivalence ratio (2) and spark advance--increasing hydrogen addition rate, a slight enhancement in electrical efficiency occurs. Furthermore, due to the engine control system and lower blends LHV (lower heating value), the methane consumption decreases disproportionately to the hydrogen amount in the mixture. Finally, referring to standard operating condition, the environmental results show that using enrichment of 10%, running the engine with 18 degrees spark advance and 2 of 1.4, CO and NOx emissions are reduced by 6.3% and 27% respectively.展开更多
Energy consumption is one of the main human activities driving global climate change, and therefore research on the carbon footprint of energy consumption is of great significance. In this paper, concepts and methods ...Energy consumption is one of the main human activities driving global climate change, and therefore research on the carbon footprint of energy consumption is of great significance. In this paper, concepts and methods relating to the carbon footprint of energy consumption were used to calculate total carbon footprint, carbon footprint of each type of energy, output value of the carbon footprint and its ecological pressure from 1990 to 2009 in Gansu Province, northwestern China. The ridge regression function within the STIRPAT model was applied to study the quantitative relationship between carbon footprint and economic growth and at the same time verify the existence of an Environmental Kuznets Curve. A decoupling index was introduced to further explore the dynamic relationship between economic growth and carbon footprint. We found that the total carbon footprint increased from 0.091 ha per capita in 1990 to 0.191 ha per capita in 2009 and fol owed a lfuctuating rising trend. Coal and oil occupy the dominant position within the carbon footprint composition, while natural gas is of little effect. The output value of the carbon footprint increased from 11 800 CNY per ha in 1990 to 25 100 CNY per ha in 2009, representing an average annual growth rate of 4.1%. The ecological pressure intensity of the carbon footprint increased to 0.24 in 2009, and remains much lower than developed provinces Jiangsu and Shanghai, due to the vast area of woodland in Gansu. Development of a low-carbon economy in Gansu remains hindered by limited energy, a fragile ecological environment and irrational energy structure. Population and GDP per capita growth were the main factors driving the increasing carbon footprint; the impact of population is 3.47 times of that of per capita GDP. Regression analysis and decoupling index analysis have proved the existence of the Environmental Kuznets Curve for economic growth and carbon footprint, but 33 years are required to reach the inlfection point.展开更多
In this paper, the life cycle assessment(LCA) method is used to evaluate and quantify the energy consumption and environmental impacts of biodegradable polylactic acid(PLA) plastic packaging from the five stages of ra...In this paper, the life cycle assessment(LCA) method is used to evaluate and quantify the energy consumption and environmental impacts of biodegradable polylactic acid(PLA) plastic packaging from the five stages of raw material acquisition, raw material transportation, product production, products use and final disposal. Seven impact categories were selected for the impact analysis: abiotic depletion potential fossil fuels(ADP), global warming potential(GWP), acidification potential(AP), eutrophication potential(EP), photochemical ozone formation potential(POCP), human toxicity potential(HTP), and terrestrial ecotoxicity potential(TETP). The results of the LCA are discussed and the results show that production of products is the highest stage of the environmental impact. Meanwhile, in the entire life cycle, the top three environmental impact categories are GWP, ADP and HTP,which account for 32.63%, 24.83% and 14.01%, respectively. The LCA results show that the environmental impact can be reduced in several ways: reducing the consumption of electricity, increasing the input of new energy, increasing the conversion rate of materials in the production process, using organic and water-soluble fertilizers instead of conventional fertilizers, using environment-friendly fuels and establishing a sound recycling system.展开更多
This paper examines the energy and environmental benefits within the whole life cycle shifting from traditional gasoline vehicles to electrified advanced vehicles under regional real-world driving behaviors. The advan...This paper examines the energy and environmental benefits within the whole life cycle shifting from traditional gasoline vehicles to electrified advanced vehicles under regional real-world driving behaviors. The advance vehicles focus on family passenger cars and include battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and hybrid electric vehicles (HEVs). The GREET (greenhouse gases, regulated emissions, and energy use in transportation) model is adopted with regional circumstances modifications, especially the UF (utility factors) of PHEVs. The results show that the electrified vehicles offer great benefits concerning energy consumption, greenhouse gas (GHG) emissions as well as urban Particulate Matter 2,5 (PMz.s) emissions. Compared to conventional gasoline vehicles, the life-cycle total energy reduction for advance vehicles is 51% to 57%. There is little difference on energy reduction among the HEVs, PHEVs and BEVs, with the energy mix shifting from petroleum to coal for the stronger electrification. The reductions of GHG emissions are 57% for HEV, 54% to 48% for PHEVs with 10 miles to 40 miles CD range, and 40% for BEV. The life-cycle and local PM2.5 emissions are discussed separately. The life-cycle PM2.5 emissions increase with vehicle electrification and reach a maximum for the BEV which are 5% higher than the conventional vehicle (CV). However, electric vehicles can shift PM2.5 emissions from vehicle operation to upstream operations and help mitigate PM2.5 emissions in urban areas. The local emissions of PHEVs and BEVs can be reduced by 37% to 81% and 100% compared with CVs.展开更多
文摘This paper introduces the energy consumption status in China, elaborate the affects of the unreasonable energy consumption structure on energy environment and sustainable development of economy. Simultaneously, it points out the solution, i.e., to implement integrated resources planning (IRP)/demand side management (DSM), and gives some recommendations on the way of implementing IRP/DSM.
基金Supported by the National Natural Science Foundation of China (No. 60403007, No. 60503006, No. 60572059)the Natural Science Foundation of Guangdong Province, China (No.05300706).
文摘Proxy signatures have been used to enable the transfer of digital signing power within some context and ring signatures can be used to provide the anonymity of a signer. By combining the functionalities of proxy signatures and ring signatures, this paper introduces a new concept, named ring proxy signature, which is a proxy signature generated by an anonymous member from a set of potential signers. The paper also constructs the first concrete ring proxy signature scheme based on the provably secure Schnorr's signatures and two ID-based ring proxy signature schemes. The security analysis is provided as well.
文摘In the last years, there has been a big development of European policies and regulations on energy saving topics. This is due to the will to reach the targets of 20-20-20. Buildings consume a lot of energy, so the legal framework related to the reduction of energy consumption in this sector has had a huge evolution. The "NZEB (nearly zero energy building)" concept was introduced in 2010, eight years after the release of the original EPBD (energy performance of buildings directive). By 2020, all new buildings and buildings that are subject to renovation should have very low energy consumption, covered for the major part by renewable sources. Designing and realizing this kind of building is a very ambitious task, which needs to be supported by appropriate tools and software. This paper presents a new tool for assessing building performance, named BENIMPACT Suite (building's environmental impact evaluator and optimizer), which is developed by EnginSoft (Italy). The suite is organized in different core modules that allow to verify how the building performance level is influenced by different design choices, such as envelope shape and materials, plant systems, renewable sources use, etc.. One of the test cases used to validate the BENIMPACT Suite energy performance is the evaluation of an interesting Italian ZEB, finished in 2010 and called CasaZeroEnergy. It is located in Felettano (Udine), a small town in northeastern Italy. This building is an experimental house designed and monitored by the Laboratory of Building Design of the University of Trento (Italy) and built by Polo Le Ville Plus Group (Cassacco-ltaly). The energy performance of this building was modelled and evaluated using BENIMPACT Suite, and simulation results were compared with monitored data.
文摘The aim of this paper is to develop a simple EV model and predict its energy consumption with a variable and fixed ratio gearbox over a standard driving cycle in order to understand whether this could offer significant efficiency gains. The powertrain of a generic electric vehicle was modelled in Matlab / Simulink using the QSS Toolkit. The electric vehicle was then fitted with different transmissions with different levels of complexity. Simulations were done to investigate the energy consumptions across 6 standard driving cycles. The emerging conclusions are that it is possible to improve overall energy consumption levels by around 5 to 12 % with a variable ratio gearbox depending on the driving cycle used. However, there are many other practical considerations which must be weighed against this positive result - and the paper discusses the impact of several of these such as, gearbox efficiency, additional weight, cost and complexity, effect on drivability and potential for motor downsizing.
基金Project(2011BAJ01B05) supported by the National Science and Technology Pillar Program during the Twelfth Five-year Plan Period of China
文摘With rapid economy growth,building energy consumption in China has been gradually increased.The energy consumption and indoor environmental quality of 51 office buildings in Hainan Province,a hot and humid area,were studied through collection of verified data in site visits and field tests.The result revealed that,electricity accounted for 99.79% of the total energy consumption,natural gas 0.17%,and diesel 0.04%.The air conditioning dominated the energy use with a share of 43.18%,equipment in the particular areas 26.90%,equipment in the office rooms 11.95%,lighting system 8.67%,general service system 7.57%,and miscellaneous items 1.73%.Statistical method including six indicators obtained the energy consumption benchmark with upper limit of 98.31 kW-h/m2 and lower limit of 55.26 kW-h/m2.According to ASHRAE standard(comfortable standard) and GB/T 18883-2002(acceptable standard),the indoor environmental quality of 51 sampled office buildings was classified into three ranks:good,normal and bad.With benchmark of building energy consumption combined with indoor environmental quality,it was found that only 3.92% of sampled buildings can be identified as the best performance buildings with low energy consumption and advanced indoor environmental quality,and the buildings classified into normal level accounted for the maximum ratio.
文摘Residential energy consumption is varying considerably worldwide. In order to understand these variations, and thus design effective policies for energy reductions, one needs a better understanding of the different drivers behind these variations. A comparison of geographical areas with similar climate and socio-economic conditions has shown significant variations in residential energy consumption across otherwise comparable case studies. This research paper aims to identify cultural and historical parameters that contribute to these significant variations, including economic, environmental and social traditions related to local availability of natural resources. Furthermore, the transferability of these parameters is evaluated, taking into consideration local legislation and planning documents, and historic and socio-economic accessibility of resources. It is evaluated to which degree these parameters can be transferred and included into building assessment tools and policy documents for planning and transformation of sustainable urban neighborhoods.
文摘Electrical energy consumption is growing and is necessary to improve the technologies related to energy production. We have carried out a pilot study about environmental impacts during the manufacturing process of PV (photovoltaic) modules and compared between the energy requirement for the production of PV cells and modules and generation throughout the life time of the finished good that is PV module. It was taken into account the generation of environmental aspects and impacts in the manufacture of monocrystalline silicon PV modules (consisting of three components: silicon cell, fiat tempered glass and aluminum frame), and an analysis of a grid-connected PV system using an energetic alternative in residences was considered. Results show that, this kind of renewable energy is really clean and can be considered as a way to change the energy technology.
文摘Located in the cold and very cold semiarid steppe climate zone, North Dakota boasts not only long cold winters but also hot summers, which significantly increases the energy consumption of buildings. In fact, North Dakota has the highest energy consumption per capita in residential buildings (101 MM Btu in 2013), and its energy consumption per capita in commercial buildings ranks the second (l 18 MM Btu in 2013) in the nation. When humans spend a long time indoors to escape the inclement weather, their health will be more susceptible to the indoor environment. In addition, North Dakota has the 3rd least number of green buildings certified by LEED (Leadership in Energy and Environmental Design) in the nation. This paper aims to investigate the status quo of buildings with respect to energy, health and sustainability in North Dakota, and attempts to propose strategies regarding research and higher education to rectify the current issues. These strategies include but not limited to forming the architectural engineering program, a comprehensive and interdisciplinary program in buildings.
基金part of a project funded by "China Chengzhen New countryside Reconstruction Studies Program of Sichuan University" (Grant No.2007-03)
文摘Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem.
文摘Athens, a metropolis characterized by agglutination and compactness, but at the same time facing numerous urban and transport issues, saw its population swell during the 20th century which led to extensive urbanization phenomena. This continued urbanization increases profoundly all urban activities with transportation being the key driver in energy consumption. Theories for sustainable cities prerequisite are the integration of a number of acts in order to reduce energy consumption, with mobility being the first consideration among others. The aim of this paper is to critically explore implemented policies and plans as well as forthcoming strategic plans in terms of sustainable mobility as imposed in large scale regeneration plans in contemporary Athens. Research focuses on strategic interventions since the 1980s, such as the Athenian Daktylios (ring road for circulation management) and its later adjustments, the upcoming pedestrianization and unification of the commercial triangle and its subsequent tram line extension as well as the notable implementation of the metropolitan cycling network. Moreover, the discussion takes into consideration the implications of the Greek economic crisis in mobility choices, as aimless travels have been reduced to a minimum, several cars have been abandoned and cyclists seem to tentatively claim some space in the urban environment. What will likely be the next day in the Athenian historic centre? Considering the transformations that are expected in the immediate future, this research paper explores their potential to enhance urban environment, reduce climate change impacts and amplify resilience.
文摘Building envelopes include facades and roof, which have the most interaction and exchange with outside and natural environment. In the future, meeting buildings various complicated needs with new technological advances necessitates a change and evolution in building envelopes. Controlling the energy consumption of the buildings is mostly through controlling the energy performance of the building envelopes. New technologies lead to the intelligent facades and envelopes. The envelope can be designed to be a part of the whole building's metabolism (energy production, storage and consumption) and morphology. The envelope would be a controlled part of the building which is managed through the central control system of the building, which connects it to other parts. It caused building envelope design to be changed fundamentally, so that there is a need to interact with engineering disciplines including computer engineering, mechanical engineering, material engineering and so on. All of these caused building envelope to get closer to biological and living systems. The physical restrictions which affect buildings system and living systems are the same. So they cause the same forces to shape the structure and form of the systems and the same rules to interact with the environment. The restrictions of material and energy resources caused living systems to be energy efficient and consuming less material. But the most important difference between living systems and building systems is in maximum use of different resources. As living systems use information maximally, the building system technology is based on using maximum energy. Now, there are many reasons and restrictions that building envelopes cannot act like living systems. But technological developments and contributing more disciplines in design and construction of building envelopes caused the future way of these envelopes get close to living systems for their energy efficiency. Some of living systems characteristics which the future building envelopes would have partially or benefit for the design process or construction are self-organization, evolution principles, hierarchical levels, processing energy, reaction to environmental stimuli and self-adjustment. Self-organization is achieved in some design software and in building material production for creating formal patterns. Evolution principles provide infrastructure for soft wares for optimization purposes and form creation. Hierarchical levels refer to giving hierarchical structure to the building envelopes through layering and designing different scales. Processing energy (metabolism) would be achieved through photovoltaic and solar collectors to produce energy and in passive systems for energy storage and distribution. Controlling solar radiation absorption and transmittance would help energy transfer from outside to building and vice versa. Reaction to environmental stimuli which is one of the most important characteristics of future building envelopes would use different types of active and passive sensors to create envelope mechanical reactions through material properties or collect data for processing in the control center to determine the right reaction. The reaction would be through different strategies such as changing properties and moving. Reaction could be passive or active. Self-adjustment can be achieved by control systems and processing units. All of these mean intelligent envelopes are essential parts of future buildings. Though it is now started with new design soft wares based on biological principles to optimize different parameters affecting the envelope function or to create the most efficient form.
文摘This paper discusses the design of the propulsion system of the UAQ4 (University of L'Aquila, model 4) magnetic levitating train which is used for transportation applications in urban environments. UAQ4 is the only magnetic levitating vehicle with resistance motion, except for aerodynamic drag and with energy consumption near zero at low speed. The feasibility of the system has been successfully verified and tested in the laboratory. Propulsion and braking are provided by a novel direct-current linear stepper motor, with the primary formed by permanent magnets distributed on central beam of the track, and the secondary by coils on board the vehicle, instead of the present alternate current linear motors that have well-known disadvantages. The motor working principles are described, and its performances are analyzed, by a finite element numerical model which allows modifying the most important parameters of the system. The main components of a full scale motor for urban transportation are measured and discussed.
文摘The aim of this paper is to present the preliminary experimental analysis results carried out on the commercial internal combustion engine set in a CHP (combined heat and power) mode, fueled by renewable hydrogen and methane mixtures. The hydrogen is produced by an alkaline electrolyser fed by a 5.8 kWp grid connected PV (photovoltaic) plant. The acceptance test conducted with hydrogen percentages ranging from 0%-10% has been carried out at partial load: 45 kW^l instead of the full power of 60 kWe~. In order to evaluate the CHP energy consumption and environmental performance (NOx and CO), the analysis was conducted for 240 h, using a portable flue gas analyser and two mass flow meters for hydrogen and methane. Without engine parameters optimization--relative equivalence ratio (2) and spark advance--increasing hydrogen addition rate, a slight enhancement in electrical efficiency occurs. Furthermore, due to the engine control system and lower blends LHV (lower heating value), the methane consumption decreases disproportionately to the hydrogen amount in the mixture. Finally, referring to standard operating condition, the environmental results show that using enrichment of 10%, running the engine with 18 degrees spark advance and 2 of 1.4, CO and NOx emissions are reduced by 6.3% and 27% respectively.
文摘Energy consumption is one of the main human activities driving global climate change, and therefore research on the carbon footprint of energy consumption is of great significance. In this paper, concepts and methods relating to the carbon footprint of energy consumption were used to calculate total carbon footprint, carbon footprint of each type of energy, output value of the carbon footprint and its ecological pressure from 1990 to 2009 in Gansu Province, northwestern China. The ridge regression function within the STIRPAT model was applied to study the quantitative relationship between carbon footprint and economic growth and at the same time verify the existence of an Environmental Kuznets Curve. A decoupling index was introduced to further explore the dynamic relationship between economic growth and carbon footprint. We found that the total carbon footprint increased from 0.091 ha per capita in 1990 to 0.191 ha per capita in 2009 and fol owed a lfuctuating rising trend. Coal and oil occupy the dominant position within the carbon footprint composition, while natural gas is of little effect. The output value of the carbon footprint increased from 11 800 CNY per ha in 1990 to 25 100 CNY per ha in 2009, representing an average annual growth rate of 4.1%. The ecological pressure intensity of the carbon footprint increased to 0.24 in 2009, and remains much lower than developed provinces Jiangsu and Shanghai, due to the vast area of woodland in Gansu. Development of a low-carbon economy in Gansu remains hindered by limited energy, a fragile ecological environment and irrational energy structure. Population and GDP per capita growth were the main factors driving the increasing carbon footprint; the impact of population is 3.47 times of that of per capita GDP. Regression analysis and decoupling index analysis have proved the existence of the Environmental Kuznets Curve for economic growth and carbon footprint, but 33 years are required to reach the inlfection point.
基金Tianjin Municipal Science and Technology Bureau(17JCYBJC42400)Tianjin Municipal Education Commission(2017KJ020)Tianjin Key Laboratory of Integrated Design and On-line Monitoring for Light Industry&Food Machinery and Equipment 2019(LIMFE08).
文摘In this paper, the life cycle assessment(LCA) method is used to evaluate and quantify the energy consumption and environmental impacts of biodegradable polylactic acid(PLA) plastic packaging from the five stages of raw material acquisition, raw material transportation, product production, products use and final disposal. Seven impact categories were selected for the impact analysis: abiotic depletion potential fossil fuels(ADP), global warming potential(GWP), acidification potential(AP), eutrophication potential(EP), photochemical ozone formation potential(POCP), human toxicity potential(HTP), and terrestrial ecotoxicity potential(TETP). The results of the LCA are discussed and the results show that production of products is the highest stage of the environmental impact. Meanwhile, in the entire life cycle, the top three environmental impact categories are GWP, ADP and HTP,which account for 32.63%, 24.83% and 14.01%, respectively. The LCA results show that the environmental impact can be reduced in several ways: reducing the consumption of electricity, increasing the input of new energy, increasing the conversion rate of materials in the production process, using organic and water-soluble fertilizers instead of conventional fertilizers, using environment-friendly fuels and establishing a sound recycling system.
基金The Ministry of Science and Technology of China(Grant Nos.2011DFA60650,2012DFA81190,2014DFG71590,2013BAG06B02 and 2013BAG06B04)
文摘This paper examines the energy and environmental benefits within the whole life cycle shifting from traditional gasoline vehicles to electrified advanced vehicles under regional real-world driving behaviors. The advance vehicles focus on family passenger cars and include battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and hybrid electric vehicles (HEVs). The GREET (greenhouse gases, regulated emissions, and energy use in transportation) model is adopted with regional circumstances modifications, especially the UF (utility factors) of PHEVs. The results show that the electrified vehicles offer great benefits concerning energy consumption, greenhouse gas (GHG) emissions as well as urban Particulate Matter 2,5 (PMz.s) emissions. Compared to conventional gasoline vehicles, the life-cycle total energy reduction for advance vehicles is 51% to 57%. There is little difference on energy reduction among the HEVs, PHEVs and BEVs, with the energy mix shifting from petroleum to coal for the stronger electrification. The reductions of GHG emissions are 57% for HEV, 54% to 48% for PHEVs with 10 miles to 40 miles CD range, and 40% for BEV. The life-cycle and local PM2.5 emissions are discussed separately. The life-cycle PM2.5 emissions increase with vehicle electrification and reach a maximum for the BEV which are 5% higher than the conventional vehicle (CV). However, electric vehicles can shift PM2.5 emissions from vehicle operation to upstream operations and help mitigate PM2.5 emissions in urban areas. The local emissions of PHEVs and BEVs can be reduced by 37% to 81% and 100% compared with CVs.