To study the indoor air qualities(IAQ)of large commercial office buildings in Hunan province of China and the corresponding improvement methods,the IAQ of a large commercial office building in Changsha in July,2008,...To study the indoor air qualities(IAQ)of large commercial office buildings in Hunan province of China and the corresponding improvement methods,the IAQ of a large commercial office building in Changsha in July,2008,is investigated.A questionnaire survey and field tests are used to collect data.According to the data of twelve rooms in this building,objective evaluation and the subjective evaluation of the IAQ are obtained.Almost all of the environmental parameters in these rooms basically meet the standards of the objective evaluation.But the average concentration of carbon dioxide in most rooms cannot reach the value of the cleanliness standards,1 255 mg/m^3.The average acceptability of the IAQ in these rooms is 71%,which is lower than the value of the ASHRAE 55—1992 standards,80%.The proper increase in the wind speed and the indoor fresh air supply can greatly improve the objective evaluation and the subjective evaluation of the IAQ.展开更多
Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numer...Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numerically investigated. Three levels of Rayleigh number(5.8×1010, 1.0×1012 and 2.1×1012) and two values of source contaminant flux(5 mg/s and 50 mg/s) were considered. The inlet Reynolds numbers were 2×104, 5×104, 1.5×105 and 4.5×105 for DV and 5×105, 1×106, 2×106 and 4×106 for PV, respectively. From the results, it is concluded that the above parameters have very complex impacts on the conjugated heat and mass transports. From points of view of acceptable indoor air quality and ventilation efficiency, PV at Re=1×106 with side-located sources and 65% of the supply air extracted through floor level outlets is the best choice when Ra=5.8×1010. However, DVs at Re=5×104 and Re=1.5×105with center-located sources and floor-mounted air suppliers are the best choices for Ra=1.0×1012 and Ra=2.1×1012, respectively. When source contaminant flux reaches 50 mg/s, local extraction as a supplement of general ventilation is recommended. The results can be a first approximation to 3D numerical investigation and preliminary ventilation system design guidelines for high-rise industrial halls.展开更多
Two inter-decadal shifts in East China summer rainfall during the last three decades of the 20th century have been identified.One shift occurred in the late 1970s and featured more rainfall in the Yangtze River valley...Two inter-decadal shifts in East China summer rainfall during the last three decades of the 20th century have been identified.One shift occurred in the late 1970s and featured more rainfall in the Yangtze River valley and prolonged drought in North China.The other shift occurred in the early 1990s and featured increased rainfall in South China.The role of black carbon(BC) aerosol in the first shift event is controversial,and it has not been documented for the second event.In this study,the authors used Geophysical Fluid Dynamics Laboratory's(GFDL's) atmospheric general circulation model known as Atmosphere and Land Model(AM2.1) ,which has been shown to capture East Asian climate variability well,to investigate these issues by conducting sensitive experiments with or without historical BC in East Asia. The results suggest that the model reproduces the first shift well,including intensified rainfall in the Yangtze River and weakened monsoonal circulation.However,the model captures only a fraction of the observed variations for the second shift event.Thus,the role of BC in modulating the two shift events is different,and its impact is relatively less important for the early 1990s event.展开更多
This paper aims at widespread presence of expansive soil which can be obtained in the project from Xiaoxita to Yaqueling first-class highway rebuilding engineering in Yichang City of Hubei Province and weathered sand ...This paper aims at widespread presence of expansive soil which can be obtained in the project from Xiaoxita to Yaqueling first-class highway rebuilding engineering in Yichang City of Hubei Province and weathered sand which can be made full use locally,many experiments have been made. Compaction experiments and expansibility index indoor experiments of undisturbed expansive soil and expansive soil mixed with sand ranging from 10 % to 50 % have been made. Through the test mixing undisturbed expansive soil with different content of weathered sand,it can change the expansive soil water characteristics and compaction characteristics. It can influence the expansibility of the expansive soil index and significantly inhibit the expansibility of the expansive soil and reach the standard of roadbed filler.展开更多
Outdoor air quality, building materials, HVAC (Heating, Ventilation, Air Conditioning) systems and people activity are important factors in human exposition of polluted indoor air. The degree of signification varies...Outdoor air quality, building materials, HVAC (Heating, Ventilation, Air Conditioning) systems and people activity are important factors in human exposition of polluted indoor air. The degree of signification varies in dependence on pollution character and its sources. Buildings eliminate significantly people exposition of outdoor pollutants, but on the other hand, buildings are significant source of indoor pollution. The contamination of indoor air is largely from the use of gas for heating and cooking appliances. A comprehensive analysis of indoor air pollution by nitrogen oxides shows that the extent of indoor air pollution and consequent exposure varies as a result of many factors mainly the differing dislribution of appliances and their level of use. This study aims to formulate a mathematical model for the production of nitrogen oxides indoors. The physical processes that determine the concentrations of indoor nitrogen oxides as a function of outdoor concentrations, indoor emission rates and building characteristics have been mathematically described. The mathematical model developed has been parameterized for typical Slovak residences. The modeling of the occurrence of indoor nitrogen oxides and verification of the model is presented in this paper.展开更多
This paper reports a study on the role of fluid flow pattern and dynamic pressure on the permeate flux through a micro filtration membrane in laboratory scale.For this purpose,a dead-end membrane cell equipped with a ...This paper reports a study on the role of fluid flow pattern and dynamic pressure on the permeate flux through a micro filtration membrane in laboratory scale.For this purpose,a dead-end membrane cell equipped with a marine type impeller was used.The impeller was set to rotate in the clockwise and counter clockwise directions with the same angular velocities in order to illustrate the effect of rotation direction on permeate flux.Consequently, permeate fluxes were measured at various impeller rotational speeds.The computational fluid dynamics(CFD)predicted dynamic pressure was related to the fluxes obtained in the experiments.Using the CFD modeling,it is proven that the change in dynamic pressure upon the membrane surface has direct effect on the permeate flux.展开更多
Daylighting studies in buildings are key parts of environmental analysis and can be easily conducted at the early stages of design as part of environmentally responsive building design as well as to inform the final a...Daylighting studies in buildings are key parts of environmental analysis and can be easily conducted at the early stages of design as part of environmentally responsive building design as well as to inform the final architectural layout and interior design. The main aim of this study is to demonstrate how such daylighting studies can be completed at the early stages of design and, at the same time, to show the impact of window design and positioning on building indoor environments. The paper is focused on a study of window influence on room daylighting in residential buildings and computer lighting simulations in software packages: Windows Daylighting System and Autodesk Ecotect Analysis, have been carried out for different style and positioning of windows using several case studies. The main findings clearly indicated that not only the window size and style matters, but also the positioning of windows considering external walls which would make a significant influence on room daylighting levels and, therefore, such daylight studies are very important for the early stage of environmental analysis during building design.展开更多
Indoor Environmental Quality (IEQ) deals with providing a healthy and comfortable indoor environment. Most of international sustainability rating systems consider IEQ as a key perspective for developing sustainable ...Indoor Environmental Quality (IEQ) deals with providing a healthy and comfortable indoor environment. Most of international sustainability rating systems consider IEQ as a key perspective for developing sustainable buildings. Educational buildings include large number of people which increase the need to provide appropriate IEQ. Accordingly, there is a critical need to frequently assess of IEQ in this type of buildings in order to maintain the satisfactory level of IEQ. This paper aims to develop a framework for assessing and improving the IEQ of educational buildings in Saudi Arabia through measuring the IEQ parameters and integrating these results with Building Information Modeling (BIM). The key IEQ parameters considered in this study include thermal comfort, indoor air quality and visual comfort. These parameters have been measured by comfort-sense system, indoor air quality meter and light meter respectively. The measured data are integrated with BIM model in order to track the IEQ problems, and to develop IEQ history over time. By using the proposed framework, the IEQ can be tracked and improved. The IEQ assessment framework has been implemented on educational building in Saudi Arabia as a case study to validate the process and perform the necessary modifications and improvements.展开更多
POE (post-occupancy evaluation) of buildings is one of the most important mechanisms which ensures that ceremonial and public building performance including its facilities is sustained. POE studies concerned with ef...POE (post-occupancy evaluation) of buildings is one of the most important mechanisms which ensures that ceremonial and public building performance including its facilities is sustained. POE studies concerned with efficiency of building performance after using and implementing with the end-user. It provides feedback on the current status of the building and proposes solutions to existing problems in addition to guidelines and design criteria for the best solutions in the future. Despite precedent research which have been undertaken in the context of building performance, aspects of evaluating building performance have not been specified and used widely in Jordan. At the commencement of this research, the concept of POE is still new in Jordan, and the local building practitioners are still unfamiliar with this approach for the evaluation of a building performance in Amman. Accordingly, there is a need to undertake this kind of research in Jordan to identify the main guidelines of POE to be applied effectively in ceremonial and public buildings. This study therefore applies POE of indoor environment of the public buildings by exploring the guidelines that can constitute a successful and effective framework for the public buildings in Amman. This was achieved using the learnt lessons from Amman City Hall building which was used as a case study and reflecting them on these where needed. Analytical and descriptive approach basis was applied, adopting a mixed method approach (qualitative and quantitative method) by using observation tool and a questionnaire survey with occupants. Context-derived data and statistics analyzed together were used to explore the guidelines of POE to be applied effectively in public buildings. A field visit and observation tool was adopted for gathering information leading to the findings and recommendations. A questionnaire was also used to extrapolate core findings of this research. This research provides a significant contribution of POE result towards improving indoor environment to ceremonial and public buildings in Jordan.展开更多
In emergence of design, it is undoubted to be informed from nature for how things get done. But in architecture, the students are not used to start up with biological investigation. Instead of analogues, it is permitt...In emergence of design, it is undoubted to be informed from nature for how things get done. But in architecture, the students are not used to start up with biological investigation. Instead of analogues, it is permitted to pursue an evolvability systematics for built emerge. The systematics relies upon the key assumptions of Kirschner who sought the characteristics of biological evolution. For an integrated design thinking of an architectural mind, this is a methodological study, which strategically adapts living forms' evolvability capacity to built-forms' structural emergence. The study outlines the evolution strategy with experimental studios of building and design. The preceding systematic is taught in distinguished courses. It is purposed to build an easy-to-apply framework for how to generate novel structures and how the spatial structure units are organized to emerge with an imagined nature as novel tectonic model. Besides, building up structural thinking into the consilience of evolution strategy, the study is also distinguished for understanding the value system of architectural mind to diagnose the genuine character of inventive built form. Strategy constructs processes. Thinking strategy concludes by the evolvability directives of studio assignments and they are given as flow-charts and project models.展开更多
Given the growing awareness of the likely catastrophic impacts of climate change and close association of climate change with global emissions of greenhouse gases (of which carbon dioxide is more prominent) , consid...Given the growing awareness of the likely catastrophic impacts of climate change and close association of climate change with global emissions of greenhouse gases (of which carbon dioxide is more prominent) , considerable research efforts have been devoted to the analysis of carbon dioxide (CO2) emissions and its relationship to sustainable development. Now GHG reduction programs have been coming into effect in many developed coun- tries that have more responsibility for historical CO2 emissions, and the studies have become mature. First, the GHG emissions accounting system is more all-inclusive and the methods are more rational with the effort of IPCC from 1995 and all other research- ers related. Second, the responsibility allocation is more rational and fair. Along with the clarity of "carbon transfer" and "carbon leakage", the perspective and methodology for allocating regional COz emissions responsibility is turning from production base to consumption base. Third, the decomposition method has become more mature and more complex. For example, the decomposition formulas are including KAYA expression and input-output expres- sion and the decomposition techniques are developed from index analysis to simple average divisia and then adaptive-weighting divisia. Fourth, projection models have become more integrated and long-term. The top-down model and bottom-up model are both inter-embedded and synergetic. Trends above give some advice for the research on CO2 in China, such as emissions factors database construction, deeper-going research on emissions responsibility and structure analysis, promotion of modeling technology and technology-environment database.展开更多
基金The National Natural Science Foundation of China(No.50878078)
文摘To study the indoor air qualities(IAQ)of large commercial office buildings in Hunan province of China and the corresponding improvement methods,the IAQ of a large commercial office building in Changsha in July,2008,is investigated.A questionnaire survey and field tests are used to collect data.According to the data of twelve rooms in this building,objective evaluation and the subjective evaluation of the IAQ are obtained.Almost all of the environmental parameters in these rooms basically meet the standards of the objective evaluation.But the average concentration of carbon dioxide in most rooms cannot reach the value of the cleanliness standards,1 255 mg/m^3.The average acceptability of the IAQ in these rooms is 71%,which is lower than the value of the ASHRAE 55—1992 standards,80%.The proper increase in the wind speed and the indoor fresh air supply can greatly improve the objective evaluation and the subjective evaluation of the IAQ.
基金Project(2011BAJ03B07)supported by National Twelve Five-year Science and Technology Support Program of ChinaProject supported by the China Scholarship Council+1 种基金Project(51276057,51376198)supported by the National Natural Science Foundation of ChinaProject(CX2014B064)supported by Hunan Provincial Innovation Foundation for Postgraduate,China
文摘Performances and efficiencies of displacement ventilation(DV) and partial ventilation(PV) for industrial halls of different configurations as well as the heat and mass transports within the industrial halls were numerically investigated. Three levels of Rayleigh number(5.8×1010, 1.0×1012 and 2.1×1012) and two values of source contaminant flux(5 mg/s and 50 mg/s) were considered. The inlet Reynolds numbers were 2×104, 5×104, 1.5×105 and 4.5×105 for DV and 5×105, 1×106, 2×106 and 4×106 for PV, respectively. From the results, it is concluded that the above parameters have very complex impacts on the conjugated heat and mass transports. From points of view of acceptable indoor air quality and ventilation efficiency, PV at Re=1×106 with side-located sources and 65% of the supply air extracted through floor level outlets is the best choice when Ra=5.8×1010. However, DVs at Re=5×104 and Re=1.5×105with center-located sources and floor-mounted air suppliers are the best choices for Ra=1.0×1012 and Ra=2.1×1012, respectively. When source contaminant flux reaches 50 mg/s, local extraction as a supplement of general ventilation is recommended. The results can be a first approximation to 3D numerical investigation and preliminary ventilation system design guidelines for high-rise industrial halls.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(Grant No.KZCX2-YW-Q11-03)
文摘Two inter-decadal shifts in East China summer rainfall during the last three decades of the 20th century have been identified.One shift occurred in the late 1970s and featured more rainfall in the Yangtze River valley and prolonged drought in North China.The other shift occurred in the early 1990s and featured increased rainfall in South China.The role of black carbon(BC) aerosol in the first shift event is controversial,and it has not been documented for the second event.In this study,the authors used Geophysical Fluid Dynamics Laboratory's(GFDL's) atmospheric general circulation model known as Atmosphere and Land Model(AM2.1) ,which has been shown to capture East Asian climate variability well,to investigate these issues by conducting sensitive experiments with or without historical BC in East Asia. The results suggest that the model reproduces the first shift well,including intensified rainfall in the Yangtze River and weakened monsoonal circulation.However,the model captures only a fraction of the observed variations for the second shift event.Thus,the role of BC in modulating the two shift events is different,and its impact is relatively less important for the early 1990s event.
文摘This paper aims at widespread presence of expansive soil which can be obtained in the project from Xiaoxita to Yaqueling first-class highway rebuilding engineering in Yichang City of Hubei Province and weathered sand which can be made full use locally,many experiments have been made. Compaction experiments and expansibility index indoor experiments of undisturbed expansive soil and expansive soil mixed with sand ranging from 10 % to 50 % have been made. Through the test mixing undisturbed expansive soil with different content of weathered sand,it can change the expansive soil water characteristics and compaction characteristics. It can influence the expansibility of the expansive soil index and significantly inhibit the expansibility of the expansive soil and reach the standard of roadbed filler.
文摘Outdoor air quality, building materials, HVAC (Heating, Ventilation, Air Conditioning) systems and people activity are important factors in human exposition of polluted indoor air. The degree of signification varies in dependence on pollution character and its sources. Buildings eliminate significantly people exposition of outdoor pollutants, but on the other hand, buildings are significant source of indoor pollution. The contamination of indoor air is largely from the use of gas for heating and cooking appliances. A comprehensive analysis of indoor air pollution by nitrogen oxides shows that the extent of indoor air pollution and consequent exposure varies as a result of many factors mainly the differing dislribution of appliances and their level of use. This study aims to formulate a mathematical model for the production of nitrogen oxides indoors. The physical processes that determine the concentrations of indoor nitrogen oxides as a function of outdoor concentrations, indoor emission rates and building characteristics have been mathematically described. The mathematical model developed has been parameterized for typical Slovak residences. The modeling of the occurrence of indoor nitrogen oxides and verification of the model is presented in this paper.
文摘This paper reports a study on the role of fluid flow pattern and dynamic pressure on the permeate flux through a micro filtration membrane in laboratory scale.For this purpose,a dead-end membrane cell equipped with a marine type impeller was used.The impeller was set to rotate in the clockwise and counter clockwise directions with the same angular velocities in order to illustrate the effect of rotation direction on permeate flux.Consequently, permeate fluxes were measured at various impeller rotational speeds.The computational fluid dynamics(CFD)predicted dynamic pressure was related to the fluxes obtained in the experiments.Using the CFD modeling,it is proven that the change in dynamic pressure upon the membrane surface has direct effect on the permeate flux.
文摘Daylighting studies in buildings are key parts of environmental analysis and can be easily conducted at the early stages of design as part of environmentally responsive building design as well as to inform the final architectural layout and interior design. The main aim of this study is to demonstrate how such daylighting studies can be completed at the early stages of design and, at the same time, to show the impact of window design and positioning on building indoor environments. The paper is focused on a study of window influence on room daylighting in residential buildings and computer lighting simulations in software packages: Windows Daylighting System and Autodesk Ecotect Analysis, have been carried out for different style and positioning of windows using several case studies. The main findings clearly indicated that not only the window size and style matters, but also the positioning of windows considering external walls which would make a significant influence on room daylighting levels and, therefore, such daylight studies are very important for the early stage of environmental analysis during building design.
文摘Indoor Environmental Quality (IEQ) deals with providing a healthy and comfortable indoor environment. Most of international sustainability rating systems consider IEQ as a key perspective for developing sustainable buildings. Educational buildings include large number of people which increase the need to provide appropriate IEQ. Accordingly, there is a critical need to frequently assess of IEQ in this type of buildings in order to maintain the satisfactory level of IEQ. This paper aims to develop a framework for assessing and improving the IEQ of educational buildings in Saudi Arabia through measuring the IEQ parameters and integrating these results with Building Information Modeling (BIM). The key IEQ parameters considered in this study include thermal comfort, indoor air quality and visual comfort. These parameters have been measured by comfort-sense system, indoor air quality meter and light meter respectively. The measured data are integrated with BIM model in order to track the IEQ problems, and to develop IEQ history over time. By using the proposed framework, the IEQ can be tracked and improved. The IEQ assessment framework has been implemented on educational building in Saudi Arabia as a case study to validate the process and perform the necessary modifications and improvements.
文摘POE (post-occupancy evaluation) of buildings is one of the most important mechanisms which ensures that ceremonial and public building performance including its facilities is sustained. POE studies concerned with efficiency of building performance after using and implementing with the end-user. It provides feedback on the current status of the building and proposes solutions to existing problems in addition to guidelines and design criteria for the best solutions in the future. Despite precedent research which have been undertaken in the context of building performance, aspects of evaluating building performance have not been specified and used widely in Jordan. At the commencement of this research, the concept of POE is still new in Jordan, and the local building practitioners are still unfamiliar with this approach for the evaluation of a building performance in Amman. Accordingly, there is a need to undertake this kind of research in Jordan to identify the main guidelines of POE to be applied effectively in ceremonial and public buildings. This study therefore applies POE of indoor environment of the public buildings by exploring the guidelines that can constitute a successful and effective framework for the public buildings in Amman. This was achieved using the learnt lessons from Amman City Hall building which was used as a case study and reflecting them on these where needed. Analytical and descriptive approach basis was applied, adopting a mixed method approach (qualitative and quantitative method) by using observation tool and a questionnaire survey with occupants. Context-derived data and statistics analyzed together were used to explore the guidelines of POE to be applied effectively in public buildings. A field visit and observation tool was adopted for gathering information leading to the findings and recommendations. A questionnaire was also used to extrapolate core findings of this research. This research provides a significant contribution of POE result towards improving indoor environment to ceremonial and public buildings in Jordan.
文摘In emergence of design, it is undoubted to be informed from nature for how things get done. But in architecture, the students are not used to start up with biological investigation. Instead of analogues, it is permitted to pursue an evolvability systematics for built emerge. The systematics relies upon the key assumptions of Kirschner who sought the characteristics of biological evolution. For an integrated design thinking of an architectural mind, this is a methodological study, which strategically adapts living forms' evolvability capacity to built-forms' structural emergence. The study outlines the evolution strategy with experimental studios of building and design. The preceding systematic is taught in distinguished courses. It is purposed to build an easy-to-apply framework for how to generate novel structures and how the spatial structure units are organized to emerge with an imagined nature as novel tectonic model. Besides, building up structural thinking into the consilience of evolution strategy, the study is also distinguished for understanding the value system of architectural mind to diagnose the genuine character of inventive built form. Strategy constructs processes. Thinking strategy concludes by the evolvability directives of studio assignments and they are given as flow-charts and project models.
基金the helpful funding from the Ministry for Science and technology of China (GrantNo. 2007BAC03A11-04)National Natural Science Foundation of China (Grant No. 41101118)+1 种基金China Postdoctor Science Foundation (Grant No. 20100480438)National Project 973 (Grant No.2012CB95570002)
文摘Given the growing awareness of the likely catastrophic impacts of climate change and close association of climate change with global emissions of greenhouse gases (of which carbon dioxide is more prominent) , considerable research efforts have been devoted to the analysis of carbon dioxide (CO2) emissions and its relationship to sustainable development. Now GHG reduction programs have been coming into effect in many developed coun- tries that have more responsibility for historical CO2 emissions, and the studies have become mature. First, the GHG emissions accounting system is more all-inclusive and the methods are more rational with the effort of IPCC from 1995 and all other research- ers related. Second, the responsibility allocation is more rational and fair. Along with the clarity of "carbon transfer" and "carbon leakage", the perspective and methodology for allocating regional COz emissions responsibility is turning from production base to consumption base. Third, the decomposition method has become more mature and more complex. For example, the decomposition formulas are including KAYA expression and input-output expres- sion and the decomposition techniques are developed from index analysis to simple average divisia and then adaptive-weighting divisia. Fourth, projection models have become more integrated and long-term. The top-down model and bottom-up model are both inter-embedded and synergetic. Trends above give some advice for the research on CO2 in China, such as emissions factors database construction, deeper-going research on emissions responsibility and structure analysis, promotion of modeling technology and technology-environment database.