The electromagnetic fields surrounding the electric and communication installations are blamed not only for cancerigenic effects, but also for negative influences on the natural electrophysiological phenomena and ＂ac...The electromagnetic fields surrounding the electric and communication installations are blamed not only for cancerigenic effects, but also for negative influences on the natural electrophysiological phenomena and ＂accused＂ of causing some degenerative diseases of the nervous system, genetic modifications with hereditary effects, mental and behavioural disturbances. This research aimed to highlight that Directive 2008 / 46 / EC had a series of positive aspects as well as drawbacks. Directive 2008 / 46 / EC of the European Parliament and of the Council amending Directive 2004 / 40 / EC on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents （electromagnetic fields） is criticized because these norms should regard not only the category of those working in different domains, but also the large category of consumers （of cell phones, microwave ovens, computers, etc.）.展开更多
Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated...Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated,trip purposes of private car travel are mainly commute and business affairs with a more flexible trip in the urban core area.And trip intensities are concentrated in a certain extent,with trip frequency being lower in the urban core area than the peripheral area.In addition,the trip time has two significant peaks occurring in the morning and afternoon,and one trough in the midday.And trip spatial distribution is mainly within commute with both residence and employment in urban area and inward commute with residence in suburban area while employment in urban area.Both kinds of commutes direct to the urban area.The study also shows that the characteristics of private car travel are principally influenced by two aspects:travelers' attributes and urban characteristics.The main travelers' social and economic attributes influenced it include the gender,education attainment,age,driving experience and per capita monthly household income.The urban characteristics influenced it mainly cover the land use pattern,public traffic facilities and spatial attributes of residential environment.展开更多
Bridges are important elements in road system and can influence the entire economy of cities and region. Usually, these structures have high financial investments for their constructions, in this way, maintenance and ...Bridges are important elements in road system and can influence the entire economy of cities and region. Usually, these structures have high financial investments for their constructions, in this way, maintenance and conservation become so important. Inspection is a technical activity that covers several operations, including performance analysis; examination; final performance report, other operations may be necessary, such as maintenance work, recovery, strengthening and rehabilitation. Technical examination together with some test methods allows a critical and parametric judgment of the bridge performance by minimizing the subjectivity of visual evaluations, and permits a more detailed diagnosis. This paper discusses the methodology to perform tests to complement the assessment recommended by DNIT （Brazilian National Department of Transport Infrastructure）, which consists only on a visual judgment. This approach provides technical basis to classify the bridges as its need and urgency of maintenance.展开更多
Over the last 45 years, the development of backbone telecommunications systems and construction of strategic oil and gas pipelines has spanned tens of thousands ofkilometres in harsh environments （arctic to tropical,...Over the last 45 years, the development of backbone telecommunications systems and construction of strategic oil and gas pipelines has spanned tens of thousands ofkilometres in harsh environments （arctic to tropical, unmanned or developing areas）. As the vast majority of these areas are without an electrical power lines infrastructure, the need arose for a highly reliable and maintenance-free power supply to allow the continuous operations of these projects. ORC （Organic Rankine Cycle） based on CCVT （closed cycle vapor turbogenerator） was specially developed for the special requirements. The paper presents the CCVT and its mode of operation, design criteria and case studies in projects implemented in the last 45 years.展开更多
文摘The electromagnetic fields surrounding the electric and communication installations are blamed not only for cancerigenic effects, but also for negative influences on the natural electrophysiological phenomena and ＂accused＂ of causing some degenerative diseases of the nervous system, genetic modifications with hereditary effects, mental and behavioural disturbances. This research aimed to highlight that Directive 2008 / 46 / EC had a series of positive aspects as well as drawbacks. Directive 2008 / 46 / EC of the European Parliament and of the Council amending Directive 2004 / 40 / EC on the minimum health and safety requirements regarding the exposure of workers to the risks arising from physical agents （electromagnetic fields） is criticized because these norms should regard not only the category of those working in different domains, but also the large category of consumers （of cell phones, microwave ovens, computers, etc.）.
基金Under the auspices of National Natural Science Foundation of China (No 40571052,40301014)
文摘Taking Guangzhou as a case,this paper adopted a questionnaire survey to gather first-hand data and analyzed the characteristics and influencing factors of private car travel in Chinese cities.As the research indicated,trip purposes of private car travel are mainly commute and business affairs with a more flexible trip in the urban core area.And trip intensities are concentrated in a certain extent,with trip frequency being lower in the urban core area than the peripheral area.In addition,the trip time has two significant peaks occurring in the morning and afternoon,and one trough in the midday.And trip spatial distribution is mainly within commute with both residence and employment in urban area and inward commute with residence in suburban area while employment in urban area.Both kinds of commutes direct to the urban area.The study also shows that the characteristics of private car travel are principally influenced by two aspects:travelers' attributes and urban characteristics.The main travelers' social and economic attributes influenced it include the gender,education attainment,age,driving experience and per capita monthly household income.The urban characteristics influenced it mainly cover the land use pattern,public traffic facilities and spatial attributes of residential environment.
文摘Bridges are important elements in road system and can influence the entire economy of cities and region. Usually, these structures have high financial investments for their constructions, in this way, maintenance and conservation become so important. Inspection is a technical activity that covers several operations, including performance analysis; examination; final performance report, other operations may be necessary, such as maintenance work, recovery, strengthening and rehabilitation. Technical examination together with some test methods allows a critical and parametric judgment of the bridge performance by minimizing the subjectivity of visual evaluations, and permits a more detailed diagnosis. This paper discusses the methodology to perform tests to complement the assessment recommended by DNIT （Brazilian National Department of Transport Infrastructure）, which consists only on a visual judgment. This approach provides technical basis to classify the bridges as its need and urgency of maintenance.
文摘Over the last 45 years, the development of backbone telecommunications systems and construction of strategic oil and gas pipelines has spanned tens of thousands ofkilometres in harsh environments （arctic to tropical, unmanned or developing areas）. As the vast majority of these areas are without an electrical power lines infrastructure, the need arose for a highly reliable and maintenance-free power supply to allow the continuous operations of these projects. ORC （Organic Rankine Cycle） based on CCVT （closed cycle vapor turbogenerator） was specially developed for the special requirements. The paper presents the CCVT and its mode of operation, design criteria and case studies in projects implemented in the last 45 years.
