The industrial sector is the primary source of carbon emissions in China.In pursuit of meeting its carbon reduction targets,China aims to promote resource consumption sustainability,reduce energy consumption,and achie...The industrial sector is the primary source of carbon emissions in China.In pursuit of meeting its carbon reduction targets,China aims to promote resource consumption sustainability,reduce energy consumption,and achieve carbon neutrality within its processing industries.An effective strategy to promote energy savings and carbon reduction throughout the life cycle of materials is by applying life cycle engineering technology.This strategy aims to attain an optimal solution for material performance,resource consumption,and environmental impact.In this study,five types of technologies were considered:raw material replacement,process reengineering,fuel replacement,energy recycling and reutilization,and material recycling and reutilization.The meaning,methodology,and development status of life cycle engineering technology abroad and domestically are discussed in detail.A multidimensional analysis of ecological design was conducted from the perspectives of resource and energy consumption,carbon emissions,product performance,and recycling of secondary resources in a manufacturing process.This coupled with an integrated method to analyze carbon emissions in the entire life cycle of a material process industry was applied to the nonferrous industry,as an example.The results provide effective ideas and solutions for achieving low or zero carbon emission production in the Chinese industry as recycled aluminum and primary aluminum based on advanced technologies had reduced resource consumption and emissions as compared to primary aluminum production.展开更多
Upon infecting a host cell,the reticulate body(RB)form of the Chlamydia bacteria simply proliferates by binary fission for an extended period.Available data show only RB units in the infected cells 20 hours post infec...Upon infecting a host cell,the reticulate body(RB)form of the Chlamydia bacteria simply proliferates by binary fission for an extended period.Available data show only RB units in the infected cells 20 hours post infection(hpi),spanning nearly half way through the development cycle.With data collected every 4 hpi,conversion to the elementary body(EB)form begins abruptly at a rapid rate sometime around 24 hpi.By modeling proliferation and conversion as simple birth and death processes,it has been shown that the optimal strategy for maximizing the total(mean)EB population at host cell lysis time is a bang-bang control qualitatively replicating the observed conversion activities.However,the simple birth and death model for the RB proliferation and conversion to EB deviates in a significant way from the available data on the evolution of the RB population after the onset of RB-to-EB conversion.By working with a more refined model that takes into account a small size threshold eligibility requirement for conversion noted in the available data,we succeed in removing the deficiency of the previous models on the evolution of the RB population without affecting the optimal bang-bang conversion strategy.展开更多
The life cycle of CIMS (Computer Integrated Manufacturing System) includes four phases:requirement analyzing, designing, implementation and running. For reducing the risk of investment and achieving better economic re...The life cycle of CIMS (Computer Integrated Manufacturing System) includes four phases:requirement analyzing, designing, implementation and running. For reducing the risk of investment and achieving better economic results the simulation technique is needed in the above four phases of CIMS life cycle. Under the support of China 863/CIMS plan a series of simulation projects are established. Some of them are finished with succeed and have been used in application. In this paper four simulation projects are introduced.(1) The Integrated Manufacturing Simulation Software (IMSS). It is an integrated platform, based on the discrete event simulation principle. It can be used to analyze and design CIMS, especially FMS; and evaluate the daily production plan.(2) The Advanced Hierarchical Control System Emulator (AHCSE), a software system, based on the finite state machine principle. It can be used to analyze and design of CIMS hicrarchical control system, and check expanded system performance before expanding.(3) The Factory Scheduling Environment (FASE), a software system based on the discrete event simulation principle and artificial intelligence technology. It can be used for shop floor scheduling. (4) The Machining Process Simulator (MPS). It can simulate the machining process of machining center by computer. It can check the correctness of NC code (including interference and confliction) and replace the real machining center to support the simulation environment for shop floor scheduling and controlling. There are three companies and universities joining in these four projects, they are: Tsinghua University,Huazhong University of Technology, Beliing Institute of Computer Application and Simulation.展开更多
Pyrolysis is a rapidly expanding chemical-based recyclable method that complements physical recycling. It avoids improper disposal of post-consumer polymers and mitigates the ecological problems linked to the producti...Pyrolysis is a rapidly expanding chemical-based recyclable method that complements physical recycling. It avoids improper disposal of post-consumer polymers and mitigates the ecological problems linked to the production of new plastic. Nevertheless, while there is a consensus that pyrolysis might be a crucial technology in the years to come, more discussions are needed to address the challenges related to scaling up, the long-term sustainability of the process, and additional variables essential to the advancement of the green economy. Herein, it emphasizes knowledge gaps and methodological issues in current Life Cycle Assessment (LCA), underlining the need for standardized techniques and updated data to support robust decision-making for adopting pyrolysis technologies in waste management strategies. For this purpose, this study reviews the LCAs of pyrolytic processes, encompassing the complete life cycle, from feedstock collection to end-product distribution, including elements such as energy consumption, greenhouse gas emissions, and waste creation. Hence, we evaluate diverse pyrolysis processes, including slow, rapid, and catalytic pyrolysis, emphasizing their distinct efficiency and environmental footprints. Furthermore, we evaluate the impact of feedstock composition, process parameters, and scale of operation on the overall sustainability of pyrolysis-based plastic waste treatment by integrating results from current literature and identifying essential research needs. Therefore, this paper argues that existing LCA studies need more coherence and accuracy. It follows a thorough evaluation of previous research and suggests new insights into methodologies and restrictions.展开更多
Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to ...Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to perform real-time evaluations to explore various design options. However, when integrated with LCCA, BIM provides a comprehensive economic perspective that helps stakeholders understand the long-term financial implications of design decisions. This study presents a methodology for developing a model that seamlessly integrates BIM and LCCA during the conceptual design stage of buildings. This integration allows for a comprehensive evaluation and analysis of the design process, ensuring that the development aligns with the principles of low carbon emissions by employing modular construction, 3D concrete printing methods, and different building design alternatives. The model considers the initial construction costs in addition to all the long-term operational, maintenance, and salvage values. It combines various tools and data through different modules, including energy analysis, Life Cycle Assessment (LCA), and Life Cycle Cost Analysis (LCCA) to execute a comprehensive assessment of the financial implications of a specific design option throughout the lifecycle of building projects. The development of the said model and its implementation involves the creation of a new plug-in for the BIM tool (i.e., Autodesk Revit) to enhance its functionalities and capabilities in forecasting the life-cycle costs of buildings in addition to generating associated cash flows, creating scenarios, and sensitivity analyses in an automatic manner. This model empowers designers to evaluate and justify their initial investments while designing and selecting potential construction methods for buildings, and enabling stakeholders to make informed decisions by assessing different design alternatives based on long-term financial considerations during the early stages of design.展开更多
In the rapid development of modern cities, the construction of green low-car</span><span style="white-space:normal;font-size:10pt;font-family:"">- </span><span style="whit...In the rapid development of modern cities, the construction of green low-car</span><span style="white-space:normal;font-size:10pt;font-family:"">- </span><span style="white-space:normal;font-size:10pt;font-family:"">bon livable cities and the realization of energy-saving and beautification of buildings </span><span style="white-space:normal;font-size:10pt;font-family:"">are</span><span style="white-space:normal;font-size:10pt;font-family:""> now being strongly promoted and ha</span><span style="white-space:normal;font-size:10pt;font-family:"">ve</span><span style="white-space:normal;font-size:10pt;font-family:"">become an important indicator of urban development. With the implementation of green building and BIM technology, the combination of BIM technology with green building is a new momentum in the development of the construction industry. The application of BIM can make the quantitative management of green buildings in the whole life cycle, get rid of the shackles of traditional models, make the design and construction process more accurate, and also make the whole pro</span><span style="white-space:normal;font-size:10pt;font-family:"">cess of green buildings more standardized. Among them, the core of BIM is the information model, and the core of green building is: low energy consum</span><span style="white-space:normal;font-size:10pt;font-family:"">ption, green and sustainable. This paper firstly explains the concepts and advantages of BIM technology and green building, and separately elaborates the significance of using both in the construction field. Secondly, the current development status of BIM technology and green building is obtained by studying and analyzing the development status and connection between them. Finally, combining BIM technology in the whole life cycle of green building, analyzing the current situation and advantages and disadvantages of using the combination of green building and BIM in actual engineering, clarifying the importance of using BIM in the whole life cycle of green building, and highlighting the combination of BIM technology and the whole life cycle of green building as an important tool for the future development of the construction industry.展开更多
The building energy efficiency is determined by the climatic region and the energy-saving measures. In this paper an assessment model for energy efficiency of the rural residential buildings in the northern China was ...The building energy efficiency is determined by the climatic region and the energy-saving measures. In this paper an assessment model for energy efficiency of the rural residential buildings in the northern China was established by the method of whole life cycle. The energy consumption of the rural residential buildings in different stages was analyzed through quantitative method in this model. At the same time, the corresponding energy efficiency assessment system was developed.展开更多
This paper analyzes the present development situations of the real estate industry, puts forwards the low carbon development strategies based on the project life cycle for the real estate enterprises, and points out t...This paper analyzes the present development situations of the real estate industry, puts forwards the low carbon development strategies based on the project life cycle for the real estate enterprises, and points out the corresponding assistant suggestions according to the predicament in the implementation of low carbon strategy. The purpose is to provide a theoretical reference for low carbon development of the real estate enterprises and the healthy and sustainable development of the real estate industry.展开更多
<span style="font-family:Verdana;">Wind technology is considered to be among the most promising types of renewable energy sources, and due to high oil prices and growing concerns about climate change a...<span style="font-family:Verdana;">Wind technology is considered to be among the most promising types of renewable energy sources, and due to high oil prices and growing concerns about climate change and energy security, it has been the subject of extensive considerations in recent years, including questions related to the relative sus</span><span style="font-family:Verdana;">tainability of electricity production when the manufacturing, assembly,</span><span style="font-family:Verdana;"> transportation and dismantling processes of these facilities are taken into account. The present article evaluates the environmental impacts, carbon emissions and water consumption, derived from the production of electric energy of the Villonaco wind farm, located in Loja</span><span style="font-family:Verdana;">, </span><span style="font-family:""><span style="font-family:Verdana;">Ecuador, during its entire life cycle, using the Life Cycle Analysis for this purpose. Finally, it is concluded that wind energy has greater environmental advantages since it has lower values of carbon and water footprints than other energy sources. Additionally, with the </span><span style="font-family:Verdana;">techniques Cumulative Energy Demand and Energy Return on Investment, sustainability in the production of electricity from wind power in Ecuador is</span><span style="font-family:Verdana;"> demonstrated;and, that due to issues of vulnerability to climate change, the diversification of its energy mix is essential considering the inclusion of non-conventional renewable sources such as solar or wind, this being the only way to reduce both the carbon footprint and the water from the energy supply.</span></span>展开更多
Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vit...Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vitamins,and bioactive substances.Additionally,they aid in improving the environment due to their higher extraction rate and lower carbon emission during the processing stage.However,few studies have attempted to evaluate the economic and social benefits of increasing the amount of whole grain in grain intake.This paper estimates the potential savings in healthcare costs and reduced food carbon footprints(CFs)that could result from a shift toward whole grain consumption following the Chinese Dietary Guidelines(CDG).We investigate hypothetical scenarios where a certain proportion(5–100%)of Chinese adults could increase their whole grain intakes as proposed by CDG to meet the average shortfall of 30.2 g.In that case,the healthcare costs for associated diseases(e.g.,type2 diabetes mellitus(T2DM),cardiovascular disease(CVD),and colorectal cancer(CRC))are expected to reduce by a substantial amount,from USD 2.82 to 56.37 billion;the carbon emission levels are also projected to decrease by0.24–5.72 million tons.This study provides compelling evidence that advocating for the transition towards greater consumption of whole grain products could benefit individual health,the environment,and society,by reducing both healthcare costs and carbon emissions.展开更多
The success of catalytic schemes for the large-scale valorization of CO_(2) does not only depend on the development of active,selective and stable catalytic materials but also on the overall process design.Here we pre...The success of catalytic schemes for the large-scale valorization of CO_(2) does not only depend on the development of active,selective and stable catalytic materials but also on the overall process design.Here we present a multidisciplinary study(from catalyst to plant and techno-economic/lifecycle analysis)for the production of green methanol from renewable H2 and CO_(2).We combine an in-depth kinetic analysis of one of the most promising recently reported methanol-synthesis catalysts(InCo)with a thorough process simulation and techno-economic assessment.We then perform a life cycle assessment of the simulated process to gauge the real environmental impact of green methanol production from CO_(2).Our results indicate that up to 1.75 ton of CO_(2) can be abated per ton of produced methanol only if renewable energy is used to run the process,while the sensitivity analysis suggest that either rock-bottom H2 prices(1.5$kg1)or severe CO_(2) taxation(300$per ton)are needed for a profitable methanol plant.Besides,we herein highlight and analyze some critical bottlenecks of the process.Especial attention has been paid to the contribution of H2 to the overall plant costs,CH4 trace formation,and purity and costs of raw gases.In addition to providing important information for policy makers and industrialists,directions for catalyst(and therefore process)improvements are outlined.展开更多
In this paper, the Life Cycle of Urban Development was firstly analyzed, and the phases of Life Cycle Assessment applied to Urban Development (ULCA) were described. As a case study, ULCA was applied in the environment...In this paper, the Life Cycle of Urban Development was firstly analyzed, and the phases of Life Cycle Assessment applied to Urban Development (ULCA) were described. As a case study, ULCA was applied in the environmental impact assessment of the land readjustment project of Hyogo District of Saga, Japan. In addition, mitigation proposals for reducing CO2 were also presented and the relevant environmental ef-fects were simulated.展开更多
The geometry of solder joint in SMT is one of the important factors whichdetermine the solder joint reliability. In this study, a type of solder joint specimen has beendesigned and is subjected to thermal cycling to f...The geometry of solder joint in SMT is one of the important factors whichdetermine the solder joint reliability. In this study, a type of solder joint specimen has beendesigned and is subjected to thermal cycling to failure between -55 ℃ to +125 ℃ with a 36℃/min heating and cooling rate and 10 min temperature holding times. The solder jointgeometry is castellated and controlled with different solder fillet shape and stand off height.A statistical analysis of the scattered thermal cycle lives of solder joints by two parameterWeibull's probability density function has been carried out in this paper. The experimentalresults show that the more reliable solder joint geometry has flat or slight convex solderfillet with a stand off height larger than 0.1 mm. The results may be the recommendedguideline to design optimal solder joint geometry.展开更多
To investigate the environmental impacts of steel deck pavement through the whole life cycle,the steel deck pavement was divided into five stages:raw materials production,asphalt mixture mixing,pavement construction,o...To investigate the environmental impacts of steel deck pavement through the whole life cycle,the steel deck pavement was divided into five stages:raw materials production,asphalt mixture mixing,pavement construction,operation management,and pavement removing stage.Based on the process-based life cycle assessment(PLCA)method,the calculation methods of energy consumption and gas emissions of two typical steel deck pavement systems(EA+EA pavement and GA+SMA pavement)were determined.The data lists of two pavements were analyzed,and the calculation model was built.Four characteristic indices including primary energy demand(PED),global warming potential(GWP),acidification potential(AP)and respiratory inorganics(RI)were used to quantify the environmental impacts of two pavements.The results show that the environmental impact of the GA+SMA pavement is more than 1.3 times that of the EA+EA pavement.Moreover,the critical stage of energy-saving and emission-reduction of EA+EA pavement and GA+SMA pavement are the raw material production stage and asphalt mixture mixing stage,respectively.展开更多
Hydrous ruthenium oxide(h-Ru O) nanoparticles and its composite with multiwalled carbon nanotubes(h-Ru O/MWCNT) were synthesized by a simple hydrothermal method and proved to have potential application as hybrid super...Hydrous ruthenium oxide(h-Ru O) nanoparticles and its composite with multiwalled carbon nanotubes(h-Ru O/MWCNT) were synthesized by a simple hydrothermal method and proved to have potential application as hybrid supercapacitor material.The h-Ru Oand h-Ru O/MWCNT were characterized for their physico-chemical properties by PXRD,BET surface area,Raman,SEM-EDS and TEM techniques.The electrochemical performance of the materials were investigated,specific capacitance(Cs) of h-Ru Oand hRu O/MWCNT estimated by their cyclic voltammetric studies were found to be 604 and 1585 F/g respectively at a scan rate of 2 m V/s in the potential range 0–1.2 V.Further,this value was found to be nearly three times higher than that of pure h-Ru O.An asymmetric supercapacitor(AS) device was fabricated by employing h-Ru O/MWCNT as the positive electrode and activated carbon as the negative electrode.The device exhibited Cs of 61.8 F/g at a scan rate of 2 m V/s.Further,the device showed excellent long term stability for 20,000 cycles with 88% capacitance retention at a high current density of 25 A/g.展开更多
Creosote-treated wooden railroad crossties have been used for more than a century to support steel rails and to transfer load from the rails to the underlying ballast while keeping the rails at the correct gauge. As t...Creosote-treated wooden railroad crossties have been used for more than a century to support steel rails and to transfer load from the rails to the underlying ballast while keeping the rails at the correct gauge. As transportation engineers look for improved service life and environmental performance in railway systems, alternatives to the creosote-treated wooden crosstie are being considered. This paper compares the cradle-to-grave environmental life cycle assessment (LCA) results of creosote-treated wooden railroad crossties with the primary alternative products: concrete and plastic composite (P/C) crossties. This LCA includes a life cycle inventory (LCI) to catalogue the input and output data from crosstie manufacture, service life, and disposition, and a life cycle impact assessment (LCIA) to evaluate greenhouse gas (GHG) emissions, fossil fuel and water use, and emissions with the potential to cause acidification, smog, ecotoxicity, and eutrophication. Comparisons of the products are made at a functional unit of 1.61 kilometers (1.0 mile) of rail-road track per year. This LCA finds that the manufacture, use, and disposition of creosote-treated wooden railroad crossties offers lower fossil fuel and water use and lesser environmental impacts than competing products manufactured of concrete and P/C.展开更多
Large-scale blooms of Phaeocystis globosa have caused serious damage to marine ecosystems in coastal waters of China.Phaeocystis blooms depend on the competitive advantage of their heteromorphic life history:colony fo...Large-scale blooms of Phaeocystis globosa have caused serious damage to marine ecosystems in coastal waters of China.Phaeocystis blooms depend on the competitive advantage of their heteromorphic life history:colony formation has the benefit of resisting herbivory by zooplankton,and solitary cells can absorb nutrients rapidly.In order to better understand the mechanisms underlying the metabolic differences between the two types of cells,morphological observations,rapid light curve analysis,fatty acid profiling,and transcriptome assessment were conducted in the laboratory.The rapid light curve of colonial cells was higher than that of solitary cells,which indicated that colonial cells had higher CO2 fixation capacity.The fatty acid level of colonial cells was evidently lower than that of solitary cells,which is consistent with down-regulated synthesis of fatty acids and up-regulated degradation of fatty acids in the transcriptome.ATP-binding cassette transporters,the TCA cycle,and biosynthesis of exopolysaccharides(EPS)also displayed obvious differences.In summary,colonial cells have stronger carbon fixation capacity.They do not synthesize fatty acids as energy storage materials but secrete EPS,which might be one of the mechanisms of colony formation.Here we present a physiological and molecular overview of the differences between solitary cells and colonial cells and thereby provide further insight to help unravel the mechanisms that help Phaeocystis globosa adapt to different environments.展开更多
LCM (life cycle management) is a systematic approach, mindset and culture that considers economic, social, and environmental factors among other factors in the decision making process throughout various business or ...LCM (life cycle management) is a systematic approach, mindset and culture that considers economic, social, and environmental factors among other factors in the decision making process throughout various business or organizational decisions that affect both inputs and outputs of a product or service life cycle. It is a product, process, or activity management system aimed at minimizing environmental and socio-economic burdens associated with an organization's product or process during its entire life cycle and value chain. LCM's application is gaining wider acceptance both in the corporate and governmental organizations as an approach to reduce ecological footprints and to improve the sustainability of human activities. But where and how can it be used in agricultural engineering applications? This study highlights the potential areas of LCM application in agricultural and allied sectors and how it can be utilized. The study revealed that LCM tools such as design for environment and life cycle analysis can be used to evaluate the environmental impacts of-and to improve the products, equipment, and structures produced by biosystems engineers as well as the processes used to generate them.展开更多
A cradle-to-grave life cycle assessment is done to identify the environmental impacts of chromated copper arsenate (CCA)-treated timber used for highway guard rail posts, to understand the processes that contribute to...A cradle-to-grave life cycle assessment is done to identify the environmental impacts of chromated copper arsenate (CCA)-treated timber used for highway guard rail posts, to understand the processes that contribute to the total impacts, and to determine how the impacts compare to the primary alternative product, galvanized steel posts. Guard rail posts are the supporting structures for highway guard rails. Transportation engineers, as well as public and regulatory interests, have increasing need to understand the environmental implications of guard rail post selection, in addition to factors such as costs and service performance. This study uses a life cycle inventory (LCI) to catalogue the input and output data from guard rail post manufacture, service life, and disposition, and a life cycle impact assessment (LCIA) to assess anthropogenic and net greenhouse gas (GHG), acidification, smog, ecotoxicity, and eutrophication potentially resulting from life cycle air emissions. Other indicators of interest also are tracked, such as fossil fuel and water use. Comparisons of guard rail post products are made at a functional unit of one post per year of service. This life cycle assessment (LCA) finds that the manufacture, use, and disposition of CCA-treated wood guard rails offers lower fossil fuel use and lower anthropogenic and net GHG emissions, acidification, smog potential, and ecotoxicity environmental impacts than impact indicator values for galvanized steel posts. Water use and eutrophication impact indicator values for CCA-treated guard rail posts are greater than impact indicator values for galvanized steel guard rail posts.展开更多
The paper has established an assessment system and a quantitative calculation method of the 'implicit' environmental impact including environmental impact indicator,resources consumption indicator and energy c...The paper has established an assessment system and a quantitative calculation method of the 'implicit' environmental impact including environmental impact indicator,resources consumption indicator and energy consumption indicator. The quantitative calculation of the environmental impact indicator is based on the life cycle assessment system and the evaluation software BEES. The paper identifies normalization reference values and weights for 12 categories of the environmental impact. It also analyzes the environmental impact indicator in life cycle stages,raw materials,transportation,manufacturing,utilization,and end of life. A university refectory project is studied. The result has shown that human health,global warming and acidification are the first three environmental impacts in 12 categories. The environmental impact indicator per m2 of this project is 18.448×10-2 standard human equivalent weight. Moreover,97.3% of the total environmental impact occurs at the raw material stage,in which the most severe environmental impact is cancerous health effect; the global warming is the main impact at the transportation and manufacturing stages; the indoor air quality impact is at the usage stage.展开更多
基金supported by the National Key Research and Development Programs(2021YFB3704201 and 2021YFB3700902).
文摘The industrial sector is the primary source of carbon emissions in China.In pursuit of meeting its carbon reduction targets,China aims to promote resource consumption sustainability,reduce energy consumption,and achieve carbon neutrality within its processing industries.An effective strategy to promote energy savings and carbon reduction throughout the life cycle of materials is by applying life cycle engineering technology.This strategy aims to attain an optimal solution for material performance,resource consumption,and environmental impact.In this study,five types of technologies were considered:raw material replacement,process reengineering,fuel replacement,energy recycling and reutilization,and material recycling and reutilization.The meaning,methodology,and development status of life cycle engineering technology abroad and domestically are discussed in detail.A multidimensional analysis of ecological design was conducted from the perspectives of resource and energy consumption,carbon emissions,product performance,and recycling of secondary resources in a manufacturing process.This coupled with an integrated method to analyze carbon emissions in the entire life cycle of a material process industry was applied to the nonferrous industry,as an example.The results provide effective ideas and solutions for achieving low or zero carbon emission production in the Chinese industry as recycled aluminum and primary aluminum based on advanced technologies had reduced resource consumption and emissions as compared to primary aluminum production.
文摘Upon infecting a host cell,the reticulate body(RB)form of the Chlamydia bacteria simply proliferates by binary fission for an extended period.Available data show only RB units in the infected cells 20 hours post infection(hpi),spanning nearly half way through the development cycle.With data collected every 4 hpi,conversion to the elementary body(EB)form begins abruptly at a rapid rate sometime around 24 hpi.By modeling proliferation and conversion as simple birth and death processes,it has been shown that the optimal strategy for maximizing the total(mean)EB population at host cell lysis time is a bang-bang control qualitatively replicating the observed conversion activities.However,the simple birth and death model for the RB proliferation and conversion to EB deviates in a significant way from the available data on the evolution of the RB population after the onset of RB-to-EB conversion.By working with a more refined model that takes into account a small size threshold eligibility requirement for conversion noted in the available data,we succeed in removing the deficiency of the previous models on the evolution of the RB population without affecting the optimal bang-bang conversion strategy.
文摘The life cycle of CIMS (Computer Integrated Manufacturing System) includes four phases:requirement analyzing, designing, implementation and running. For reducing the risk of investment and achieving better economic results the simulation technique is needed in the above four phases of CIMS life cycle. Under the support of China 863/CIMS plan a series of simulation projects are established. Some of them are finished with succeed and have been used in application. In this paper four simulation projects are introduced.(1) The Integrated Manufacturing Simulation Software (IMSS). It is an integrated platform, based on the discrete event simulation principle. It can be used to analyze and design CIMS, especially FMS; and evaluate the daily production plan.(2) The Advanced Hierarchical Control System Emulator (AHCSE), a software system, based on the finite state machine principle. It can be used to analyze and design of CIMS hicrarchical control system, and check expanded system performance before expanding.(3) The Factory Scheduling Environment (FASE), a software system based on the discrete event simulation principle and artificial intelligence technology. It can be used for shop floor scheduling. (4) The Machining Process Simulator (MPS). It can simulate the machining process of machining center by computer. It can check the correctness of NC code (including interference and confliction) and replace the real machining center to support the simulation environment for shop floor scheduling and controlling. There are three companies and universities joining in these four projects, they are: Tsinghua University,Huazhong University of Technology, Beliing Institute of Computer Application and Simulation.
文摘Pyrolysis is a rapidly expanding chemical-based recyclable method that complements physical recycling. It avoids improper disposal of post-consumer polymers and mitigates the ecological problems linked to the production of new plastic. Nevertheless, while there is a consensus that pyrolysis might be a crucial technology in the years to come, more discussions are needed to address the challenges related to scaling up, the long-term sustainability of the process, and additional variables essential to the advancement of the green economy. Herein, it emphasizes knowledge gaps and methodological issues in current Life Cycle Assessment (LCA), underlining the need for standardized techniques and updated data to support robust decision-making for adopting pyrolysis technologies in waste management strategies. For this purpose, this study reviews the LCAs of pyrolytic processes, encompassing the complete life cycle, from feedstock collection to end-product distribution, including elements such as energy consumption, greenhouse gas emissions, and waste creation. Hence, we evaluate diverse pyrolysis processes, including slow, rapid, and catalytic pyrolysis, emphasizing their distinct efficiency and environmental footprints. Furthermore, we evaluate the impact of feedstock composition, process parameters, and scale of operation on the overall sustainability of pyrolysis-based plastic waste treatment by integrating results from current literature and identifying essential research needs. Therefore, this paper argues that existing LCA studies need more coherence and accuracy. It follows a thorough evaluation of previous research and suggests new insights into methodologies and restrictions.
文摘Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to perform real-time evaluations to explore various design options. However, when integrated with LCCA, BIM provides a comprehensive economic perspective that helps stakeholders understand the long-term financial implications of design decisions. This study presents a methodology for developing a model that seamlessly integrates BIM and LCCA during the conceptual design stage of buildings. This integration allows for a comprehensive evaluation and analysis of the design process, ensuring that the development aligns with the principles of low carbon emissions by employing modular construction, 3D concrete printing methods, and different building design alternatives. The model considers the initial construction costs in addition to all the long-term operational, maintenance, and salvage values. It combines various tools and data through different modules, including energy analysis, Life Cycle Assessment (LCA), and Life Cycle Cost Analysis (LCCA) to execute a comprehensive assessment of the financial implications of a specific design option throughout the lifecycle of building projects. The development of the said model and its implementation involves the creation of a new plug-in for the BIM tool (i.e., Autodesk Revit) to enhance its functionalities and capabilities in forecasting the life-cycle costs of buildings in addition to generating associated cash flows, creating scenarios, and sensitivity analyses in an automatic manner. This model empowers designers to evaluate and justify their initial investments while designing and selecting potential construction methods for buildings, and enabling stakeholders to make informed decisions by assessing different design alternatives based on long-term financial considerations during the early stages of design.
文摘In the rapid development of modern cities, the construction of green low-car</span><span style="white-space:normal;font-size:10pt;font-family:"">- </span><span style="white-space:normal;font-size:10pt;font-family:"">bon livable cities and the realization of energy-saving and beautification of buildings </span><span style="white-space:normal;font-size:10pt;font-family:"">are</span><span style="white-space:normal;font-size:10pt;font-family:""> now being strongly promoted and ha</span><span style="white-space:normal;font-size:10pt;font-family:"">ve</span><span style="white-space:normal;font-size:10pt;font-family:"">become an important indicator of urban development. With the implementation of green building and BIM technology, the combination of BIM technology with green building is a new momentum in the development of the construction industry. The application of BIM can make the quantitative management of green buildings in the whole life cycle, get rid of the shackles of traditional models, make the design and construction process more accurate, and also make the whole pro</span><span style="white-space:normal;font-size:10pt;font-family:"">cess of green buildings more standardized. Among them, the core of BIM is the information model, and the core of green building is: low energy consum</span><span style="white-space:normal;font-size:10pt;font-family:"">ption, green and sustainable. This paper firstly explains the concepts and advantages of BIM technology and green building, and separately elaborates the significance of using both in the construction field. Secondly, the current development status of BIM technology and green building is obtained by studying and analyzing the development status and connection between them. Finally, combining BIM technology in the whole life cycle of green building, analyzing the current situation and advantages and disadvantages of using the combination of green building and BIM in actual engineering, clarifying the importance of using BIM in the whole life cycle of green building, and highlighting the combination of BIM technology and the whole life cycle of green building as an important tool for the future development of the construction industry.
文摘The building energy efficiency is determined by the climatic region and the energy-saving measures. In this paper an assessment model for energy efficiency of the rural residential buildings in the northern China was established by the method of whole life cycle. The energy consumption of the rural residential buildings in different stages was analyzed through quantitative method in this model. At the same time, the corresponding energy efficiency assessment system was developed.
文摘This paper analyzes the present development situations of the real estate industry, puts forwards the low carbon development strategies based on the project life cycle for the real estate enterprises, and points out the corresponding assistant suggestions according to the predicament in the implementation of low carbon strategy. The purpose is to provide a theoretical reference for low carbon development of the real estate enterprises and the healthy and sustainable development of the real estate industry.
文摘<span style="font-family:Verdana;">Wind technology is considered to be among the most promising types of renewable energy sources, and due to high oil prices and growing concerns about climate change and energy security, it has been the subject of extensive considerations in recent years, including questions related to the relative sus</span><span style="font-family:Verdana;">tainability of electricity production when the manufacturing, assembly,</span><span style="font-family:Verdana;"> transportation and dismantling processes of these facilities are taken into account. The present article evaluates the environmental impacts, carbon emissions and water consumption, derived from the production of electric energy of the Villonaco wind farm, located in Loja</span><span style="font-family:Verdana;">, </span><span style="font-family:""><span style="font-family:Verdana;">Ecuador, during its entire life cycle, using the Life Cycle Analysis for this purpose. Finally, it is concluded that wind energy has greater environmental advantages since it has lower values of carbon and water footprints than other energy sources. Additionally, with the </span><span style="font-family:Verdana;">techniques Cumulative Energy Demand and Energy Return on Investment, sustainability in the production of electricity from wind power in Ecuador is</span><span style="font-family:Verdana;"> demonstrated;and, that due to issues of vulnerability to climate change, the diversification of its energy mix is essential considering the inclusion of non-conventional renewable sources such as solar or wind, this being the only way to reduce both the carbon footprint and the water from the energy supply.</span></span>
基金the National Natural Science Foundation of China(72203214 and 72061147002)China Scholarship Council(CSC)(201913043)。
文摘Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vitamins,and bioactive substances.Additionally,they aid in improving the environment due to their higher extraction rate and lower carbon emission during the processing stage.However,few studies have attempted to evaluate the economic and social benefits of increasing the amount of whole grain in grain intake.This paper estimates the potential savings in healthcare costs and reduced food carbon footprints(CFs)that could result from a shift toward whole grain consumption following the Chinese Dietary Guidelines(CDG).We investigate hypothetical scenarios where a certain proportion(5–100%)of Chinese adults could increase their whole grain intakes as proposed by CDG to meet the average shortfall of 30.2 g.In that case,the healthcare costs for associated diseases(e.g.,type2 diabetes mellitus(T2DM),cardiovascular disease(CVD),and colorectal cancer(CRC))are expected to reduce by a substantial amount,from USD 2.82 to 56.37 billion;the carbon emission levels are also projected to decrease by0.24–5.72 million tons.This study provides compelling evidence that advocating for the transition towards greater consumption of whole grain products could benefit individual health,the environment,and society,by reducing both healthcare costs and carbon emissions.
基金support from the King Abdullah University of Science and Technology(KAUST).T.Cordero-Lanzac and A.T.Aguayo acknowledge the financial support received from the Spanish Ministry of Science and Innovation with some ERDF funds(CTQ2016-77812-R)the Basque Government(IT1218-19)+2 种基金T.Cordero-Lanzac also acknowledges the Spanish Ministry of Education,Culture and Sport for the award of his FPU grant(FPU15-01666)A.Navajas and L.M.Gandía gratefully acknowledge the financial support from Spanish Ministerio de Ciencia,Innovación y Universidades,and the European Regional Development Fund(ERDF/FEDER)(grant RTI2018-096294-B-C31)L.M.Gandía also thanks Banco de Santander and Universidad Pública de Navarra for their financial support under“Programa de Intensificación de la Investigación 2018”initiative.
文摘The success of catalytic schemes for the large-scale valorization of CO_(2) does not only depend on the development of active,selective and stable catalytic materials but also on the overall process design.Here we present a multidisciplinary study(from catalyst to plant and techno-economic/lifecycle analysis)for the production of green methanol from renewable H2 and CO_(2).We combine an in-depth kinetic analysis of one of the most promising recently reported methanol-synthesis catalysts(InCo)with a thorough process simulation and techno-economic assessment.We then perform a life cycle assessment of the simulated process to gauge the real environmental impact of green methanol production from CO_(2).Our results indicate that up to 1.75 ton of CO_(2) can be abated per ton of produced methanol only if renewable energy is used to run the process,while the sensitivity analysis suggest that either rock-bottom H2 prices(1.5$kg1)or severe CO_(2) taxation(300$per ton)are needed for a profitable methanol plant.Besides,we herein highlight and analyze some critical bottlenecks of the process.Especial attention has been paid to the contribution of H2 to the overall plant costs,CH4 trace formation,and purity and costs of raw gases.In addition to providing important information for policy makers and industrialists,directions for catalyst(and therefore process)improvements are outlined.
文摘In this paper, the Life Cycle of Urban Development was firstly analyzed, and the phases of Life Cycle Assessment applied to Urban Development (ULCA) were described. As a case study, ULCA was applied in the environmental impact assessment of the land readjustment project of Hyogo District of Saga, Japan. In addition, mitigation proposals for reducing CO2 were also presented and the relevant environmental ef-fects were simulated.
文摘The geometry of solder joint in SMT is one of the important factors whichdetermine the solder joint reliability. In this study, a type of solder joint specimen has beendesigned and is subjected to thermal cycling to failure between -55 ℃ to +125 ℃ with a 36℃/min heating and cooling rate and 10 min temperature holding times. The solder jointgeometry is castellated and controlled with different solder fillet shape and stand off height.A statistical analysis of the scattered thermal cycle lives of solder joints by two parameterWeibull's probability density function has been carried out in this paper. The experimentalresults show that the more reliable solder joint geometry has flat or slight convex solderfillet with a stand off height larger than 0.1 mm. The results may be the recommendedguideline to design optimal solder joint geometry.
基金The National Key Research and Development Project of China(No.2018YFB1600304)the National Natural Science Foundation of China(No.51878167,51678146)the National Natural Science Foundation of Xizang,China(No.XZ2018ZRG-10)。
文摘To investigate the environmental impacts of steel deck pavement through the whole life cycle,the steel deck pavement was divided into five stages:raw materials production,asphalt mixture mixing,pavement construction,operation management,and pavement removing stage.Based on the process-based life cycle assessment(PLCA)method,the calculation methods of energy consumption and gas emissions of two typical steel deck pavement systems(EA+EA pavement and GA+SMA pavement)were determined.The data lists of two pavements were analyzed,and the calculation model was built.Four characteristic indices including primary energy demand(PED),global warming potential(GWP),acidification potential(AP)and respiratory inorganics(RI)were used to quantify the environmental impacts of two pavements.The results show that the environmental impact of the GA+SMA pavement is more than 1.3 times that of the EA+EA pavement.Moreover,the critical stage of energy-saving and emission-reduction of EA+EA pavement and GA+SMA pavement are the raw material production stage and asphalt mixture mixing stage,respectively.
基金financially supported by NRB-Naval Research Board(Project Number-NRB-290/MAT/12-13)
文摘Hydrous ruthenium oxide(h-Ru O) nanoparticles and its composite with multiwalled carbon nanotubes(h-Ru O/MWCNT) were synthesized by a simple hydrothermal method and proved to have potential application as hybrid supercapacitor material.The h-Ru Oand h-Ru O/MWCNT were characterized for their physico-chemical properties by PXRD,BET surface area,Raman,SEM-EDS and TEM techniques.The electrochemical performance of the materials were investigated,specific capacitance(Cs) of h-Ru Oand hRu O/MWCNT estimated by their cyclic voltammetric studies were found to be 604 and 1585 F/g respectively at a scan rate of 2 m V/s in the potential range 0–1.2 V.Further,this value was found to be nearly three times higher than that of pure h-Ru O.An asymmetric supercapacitor(AS) device was fabricated by employing h-Ru O/MWCNT as the positive electrode and activated carbon as the negative electrode.The device exhibited Cs of 61.8 F/g at a scan rate of 2 m V/s.Further,the device showed excellent long term stability for 20,000 cycles with 88% capacitance retention at a high current density of 25 A/g.
文摘Creosote-treated wooden railroad crossties have been used for more than a century to support steel rails and to transfer load from the rails to the underlying ballast while keeping the rails at the correct gauge. As transportation engineers look for improved service life and environmental performance in railway systems, alternatives to the creosote-treated wooden crosstie are being considered. This paper compares the cradle-to-grave environmental life cycle assessment (LCA) results of creosote-treated wooden railroad crossties with the primary alternative products: concrete and plastic composite (P/C) crossties. This LCA includes a life cycle inventory (LCI) to catalogue the input and output data from crosstie manufacture, service life, and disposition, and a life cycle impact assessment (LCIA) to evaluate greenhouse gas (GHG) emissions, fossil fuel and water use, and emissions with the potential to cause acidification, smog, ecotoxicity, and eutrophication. Comparisons of the products are made at a functional unit of 1.61 kilometers (1.0 mile) of rail-road track per year. This LCA finds that the manufacture, use, and disposition of creosote-treated wooden railroad crossties offers lower fossil fuel and water use and lesser environmental impacts than competing products manufactured of concrete and P/C.
基金This work was supported by the National Key R&D Program of China(No.2017YFC1404300)the National Natural Science Foundation of China(Nos.41976082,41676144 and 31670266)the Natural Science Foundation of Guangdong Province(No.2017A030313115).
文摘Large-scale blooms of Phaeocystis globosa have caused serious damage to marine ecosystems in coastal waters of China.Phaeocystis blooms depend on the competitive advantage of their heteromorphic life history:colony formation has the benefit of resisting herbivory by zooplankton,and solitary cells can absorb nutrients rapidly.In order to better understand the mechanisms underlying the metabolic differences between the two types of cells,morphological observations,rapid light curve analysis,fatty acid profiling,and transcriptome assessment were conducted in the laboratory.The rapid light curve of colonial cells was higher than that of solitary cells,which indicated that colonial cells had higher CO2 fixation capacity.The fatty acid level of colonial cells was evidently lower than that of solitary cells,which is consistent with down-regulated synthesis of fatty acids and up-regulated degradation of fatty acids in the transcriptome.ATP-binding cassette transporters,the TCA cycle,and biosynthesis of exopolysaccharides(EPS)also displayed obvious differences.In summary,colonial cells have stronger carbon fixation capacity.They do not synthesize fatty acids as energy storage materials but secrete EPS,which might be one of the mechanisms of colony formation.Here we present a physiological and molecular overview of the differences between solitary cells and colonial cells and thereby provide further insight to help unravel the mechanisms that help Phaeocystis globosa adapt to different environments.
文摘LCM (life cycle management) is a systematic approach, mindset and culture that considers economic, social, and environmental factors among other factors in the decision making process throughout various business or organizational decisions that affect both inputs and outputs of a product or service life cycle. It is a product, process, or activity management system aimed at minimizing environmental and socio-economic burdens associated with an organization's product or process during its entire life cycle and value chain. LCM's application is gaining wider acceptance both in the corporate and governmental organizations as an approach to reduce ecological footprints and to improve the sustainability of human activities. But where and how can it be used in agricultural engineering applications? This study highlights the potential areas of LCM application in agricultural and allied sectors and how it can be utilized. The study revealed that LCM tools such as design for environment and life cycle analysis can be used to evaluate the environmental impacts of-and to improve the products, equipment, and structures produced by biosystems engineers as well as the processes used to generate them.
文摘A cradle-to-grave life cycle assessment is done to identify the environmental impacts of chromated copper arsenate (CCA)-treated timber used for highway guard rail posts, to understand the processes that contribute to the total impacts, and to determine how the impacts compare to the primary alternative product, galvanized steel posts. Guard rail posts are the supporting structures for highway guard rails. Transportation engineers, as well as public and regulatory interests, have increasing need to understand the environmental implications of guard rail post selection, in addition to factors such as costs and service performance. This study uses a life cycle inventory (LCI) to catalogue the input and output data from guard rail post manufacture, service life, and disposition, and a life cycle impact assessment (LCIA) to assess anthropogenic and net greenhouse gas (GHG), acidification, smog, ecotoxicity, and eutrophication potentially resulting from life cycle air emissions. Other indicators of interest also are tracked, such as fossil fuel and water use. Comparisons of guard rail post products are made at a functional unit of one post per year of service. This life cycle assessment (LCA) finds that the manufacture, use, and disposition of CCA-treated wood guard rails offers lower fossil fuel use and lower anthropogenic and net GHG emissions, acidification, smog potential, and ecotoxicity environmental impacts than impact indicator values for galvanized steel posts. Water use and eutrophication impact indicator values for CCA-treated guard rail posts are greater than impact indicator values for galvanized steel guard rail posts.
基金supported by the Special Research Foundation of Doctoral Subjects in University of China (No.20050487017)
文摘The paper has established an assessment system and a quantitative calculation method of the 'implicit' environmental impact including environmental impact indicator,resources consumption indicator and energy consumption indicator. The quantitative calculation of the environmental impact indicator is based on the life cycle assessment system and the evaluation software BEES. The paper identifies normalization reference values and weights for 12 categories of the environmental impact. It also analyzes the environmental impact indicator in life cycle stages,raw materials,transportation,manufacturing,utilization,and end of life. A university refectory project is studied. The result has shown that human health,global warming and acidification are the first three environmental impacts in 12 categories. The environmental impact indicator per m2 of this project is 18.448×10-2 standard human equivalent weight. Moreover,97.3% of the total environmental impact occurs at the raw material stage,in which the most severe environmental impact is cancerous health effect; the global warming is the main impact at the transportation and manufacturing stages; the indoor air quality impact is at the usage stage.