被引排行
A RESEARCH ON COAL SEAM WATER INFUSION COURSE AND COAL BODY WETNESS MECHANISM
WANG Qing-song~1, JIN Long-zhe~2, SUN Jin-hua~1 (1 State Key Laboratory of Fire Science, University of Science and Technology of China, Hefei 230026, China; 2 School of Civil & Environmental Engineering, University of Science and Technology of Beijing, Beijing 100083, China)This paper has made an analysis of the dynamics and the course of coal seam water infusion with the purpose to decrease the dust in the coal mine production. The force involving the water infusion into the coal seam are infusion press, capillary attraction and gas press while the courses include the water entering, storing and adsorbing. To increase the infusion efficiency, the coal surface wetness course has been analyzed with the interface chemistry theory, which involves the course of bedew, soakage and spread. Then, the author has studied the automatic conditions of seam coal wetting. It means that the wetness power must be positive in nature and, at the same time, it is necessary to set the assessment criterion of the wetness course. The above analysis helps to disclose the dustproof wetness mechanism of the infusion. The infused water wet through the original smut will then soak every single part effectively and change the coal body's physics and mechanical features. The mechanism presented in this paper can thus provide the basic theory for the coal seam water infusion.
REVIEW OF THE RESEARCHES OF CONSTRUCTION SAFETY MANAGEMENT
FANG Dong-ping, HUANG Xin-yu & John C.W. Wong (Tsinghua-Gammon Construction Safety Research Center, Tsinghua University, Beijing 100081, China)Construction industry is of great significance to the economic growth in most countries. However, due to the distinct characteristics,its performance of safety and health has long been unacceptable, and constrains the continuous improvement of productivity and quality as well as the reputation and sustainable development of the industry. In China, researches on construction safety have long been behind the development of construction industry. Safety records of construction industry in China are far from being satisfactory. It is estimated that in China, over 3 000 workers are killed and billions of Chinese currency RMB are lost each year because of accidents in situ. As nearly 35 000 000 labors are employed in construction industry in China, the improvement of safety condition will save thousands of lives and billions of RMB each year. Therefore, research work on safety management is an urgent demand, especially in the aspect of management. In the present paper, advanced research works in construction safety management are reviewed in the aspects of culture, cost, and organization respectively.First,the safety culture of construction and the functions of all sides participating in the project of construction are dicussed.The attention is paid to the Total Safety Cufture.Second,the present state of the counting of cost and profit of constructron safety are reviewed.In order to calculate the cost and profit of construction safety,the indirect loss using different methods is discussed in detail.Thirdly,the progresses in management and organization of construction safety are summerized. Theories such as TSM(Total Safety Management) is discussed. Suggestions for further researches and investigation of construction safety are brought out as follows: (1) Make full use of the existing resources of construction industry to improve safety management based on the quantitative and qualitative analysis of factors influencing safety performance in situ; (2) Thoroughly investigate into the true cost and benefit of construction safety in order to harmonize safety with quality, schedule and cost when conflicts between them occur; (3) Safety culture in different levels are essential to the goal of "zero accident" in situ, researches into cultural effects on safety psychology and performance of workers will certainly help workers to work more safely; (4) Technological development, especially in the aspect of construction machinery, should be carefully designed and studied in order to eliminate the risks of accidents.
RESEARCH AND ADVANCE IN WASTEWATER TREATMENT BY FLOTATION
WEI Zai shan, XU Xiao jun, NING Ping & XU Jin qiu (College of Environmental and Engineering, Kunming University of Science and Technology, Kunming 650093, China)In the present paper, research, theory, equipment, application and prospect of flotation technique in wastewater treatment are summarized. Flotation method is a high speed and efficient technique in separation of solid and liquid. Flotation technique is paid close attention to by domestic and abroad scholars in the field of wastewater treatment. The techniques have been developed quickly since 1970, being used comprehensively in treating house sewage of urban, all kinds of industrial wastewater, as well as water supply, especially in purifying water of low temperature, low turbidity and rich algae. Flotation technigue not only substitute for sedimentation, but also serve as treatment of wastewater in advance, as well as contraction sludge. Compared with sedimentation, flotation technique has many advantages such as: (1) small occupying equipment, economical investment of capital construction; (2) good treatment efficiency, it treats plankton of low turbidity, rich algae water and original water that removed difficultly by sedimentation; (3) more economical in coagulant quantity than that of sedimentation; (4) reclaiming useful materials. There are many kinds of flotation, such as eletroflotation, disperse air flotation, dissolve air flotation according to ways of producing tiny air bubble. Industrial equipment of high efficient flotation includes flotation column, flotation pool and flotation machine. After treatment of wastewater containing oil and emulsion by flotation technique, total removal efficiency of COD cr and oil are 80%~99.5% and 70%~99.9% respectively, and every index is up to effluent standard. Also flotation can treats wastewater from a paper mill, reclaiming useful materials such as pulp fiber and packing materials, and the removal efficiency of BOD 5, COD cr , SS, TP are all 80%~90%. It is well known that it not only treats electrolytic cobalt wastewater and wastewater containing heavy metal ions, ions dyeing liquid and wool scouring effluent, but also treats tannery wastewater and house sewage of urban better, removes trihalomethane precursors from eutrophic water.
On the ship pollutant emission inventory in Shanghai port
FU Qing-yan,SHEN Yin,ZHANG Jian(Shanghai Environmental Monitoring Center,Shanghai 200030,China)The present paper attempts to introduce its study on the shipping pollutant emission inventory by taking Shanghai Port as a case sample.As is reported,Shanghai port succeeded in handling 29.07 million TEUs in 2010,thus ranking the world's busiest container-shipping champion in taking the place of Singaporean port.What is more,having accomplished a cargo shipment of 650 million tons in 2010,Shanghai port has been already honored as champion in this connection in the world for consecutive four years since 2006.Great as the advancement in vessel-shipment inventory may be,it is undeniable that,with the corresponding shipping emissions,which has in turn brought about tremendous environmental impact on the air and water,and even on the entire environment of the metropolis.And,consequently,it has become urgent to work out a reliable and up-to-date ship emission inventory and take immediate measures to limit and reduce the negative impact of shipping emission on the city.It is just for this urgent need that we have investigated the emission inventory of criteria pollutants and green house gases of vessels in the port based on the bottom-up driving mode in 2010.With a detailed survey made and activity analysis on the registration records,vessels types,tonnage distribution,driving modes,emission factors and fuel correction factors,we have worked out a total emission inventory of the vessels in and out Shanghai port by using the emission estimation methods.And,then,we have further divided the above said shipment emission into 9 types of vessels under 4 driving modes within the outer port and the inner river water-ways.Furthermore,we have achieved the spatial distribution of pollutants and green house gases based on the resolution of 1 km × 1 km grids to meet the demands of the numeric modeling,supported by the automatic identification system(AIS) in our paper.Thus,it can be followed that the total emissions of PM10,PM2.5,DPM,NOx,SOx,CO and HC by vessels were found to be equal to 4 600 ton,3 700 ton,4 400 ton,57.3 thousand ton,35.4 thousand ton,4 900 ton and 2 100 ton in 2010.The entire shipment was accounted to have produced green house gases with 2.885 5 million ton of CO2,100 ton of N2O and 40 ton of N2O.Comparing the total emission inventory in Shanghai,we have got to know that the share of the shipment contribution of the metropolis is equal to 12.0%,9.0% and 5.3% of the three key pollutants,including SO2,NOx and PM2.5.Of all the kinds of shipment,the ocean-going vessels are responsible for the total emission inventory with the shares of 12.0%,8.4% and 5.1%,respectively.
PHYTOAVAILABILITY OF CORNS TO HEAVY METAL Pb CONTENT IN THE SOILS AND ITS BENEFIT TO THE ENVIRONMENTAL AMELIORATION
KUANG Shao-ping, XU Zhong & ZHANG Shu-sheng (Department of Applied Chemistry, Qingdao Institute of Chemical Technology, Qingdao 266042, Shandong,China)The present paper is aimed at testing and investigating the pot-growing corns to find the influence of some heavy metal content on the soil. The author's investigation indicates that such crops did not show any macro-toxic signs in the presence of some observed Pb-added content (04 000 mg/kg) to the soil. On the contrary, lead in the soil can easily be absorbed by the crops and spread over in their different parts. Statistical analyses prove that the Pb content of the crops is strongly positive to their counterparts of the soil. In crops, the Pb content in the roots can be the highest, from tens to thousands of times higher than that in the stems, leaves and seeds. Thus it can be suggested that the roots might be the barriers to the Pb absorption by the stems, leaves as well as the seeds. Based on the root's strong adsorption to lead, the Pb in heavy metal polluted soil can be gradually decreased by planting crops and subsequently removing the roots in soil. This biotechnology can be used in environmental amelioration and remediation to benefit both a sustainable agricultural economy and a healthy, environment-friendly ecological system.
Determination of heat release rate curve when designing fire
WANG Zhi-gang;NI Zhao-peng;WANG Zong--cun;JIANG Ming-li Fire Code Division of Tianjin Fire Research Institute, Tianjin 300381, ChinaHeat release rate is one of the most important parameters in the process of fire development. It is essential to determine correct and reasonable heat release rate curve when conducting performance-based fire safety design with fire simulation model. Unfortunately, no combustion model is included in most fire models since it is still an enormous challenge to simulate the combustion process of fire based on the current technology. This paper attempts to find some applicable methods which can help model users to determine heat release rate curve by themselves. According to some research results of a china's 10th 5-year plan key research project named "technical guideline on the performance-based fire safety design" and some experience got from some case studies of performance — based fire safety design, several practical methods are presented to determine the heat release rate curve in different situations which can represent the realistic fire scenario. The applicability of each method is also discussed. A set of examples are illustrated at the same time.
Study on emergency decision support system of urban community safety based on GIS
XU Zhi-sheng, FENG Kai, XU Liang, FENG Chun-ying( Disaster Prevention Science and Safety Technology Institute, Central South University, Changsha 410075, China)The paper aims to introduce the process of developing the emergency decision support system of urban community safety. As is known, the decisions towards unexpected accidents in the city mainly traditionally rely on the experience and ability of the decision-makers, which inevitably involves too many subjective factors and unavoidable consequences in the process of emergency response. This accounts for the geographic information systems integration with the decision support system to be adopted for the development of the urban community safety emergency decision support systems. The present author intends to illustrate the goals, structural framework and functions of the systems. In addition, we also suggest the necessary technological scheme to build a high-speed and highly efficient spatial database. Based on the visualization and digitalization of infrastructure and disaster information, the decision support system incorporated with the disaster information management, disaster prevention plan and emergency decision pattern has been established, so as to provide the decision-makers with the power to choose schemes to manage and direct the actions to be taken more efficiently in the process of immediate and long term recovery.
Statistical analysis on water pollution incident in urban water supply area in China during the year 1985 to 2005
ZHANG Yong, WANG Dong-yu, YANG Kai(Department of Environmental Science, East China Normal University, Shanghai 200062, China; Key Laboratory of Urbanization and Ecological Restoration, Shanghai 200062, China)This paper is aimed to provide a summary of the major water pollution accidents in the urban water supply areas in China during the year 1985 to 2005 in order to explore the regularity and characteristics of such accidents and their potential risks to our urban water supply system. In doing so, the paper has summarized four aspects of such incidents, including the dates, sites, pollutant types and brief descriptions of the accidents through reviewing the reports of The Chinese Environmental News and People Daily and other media and databases during the year 1985 to 2005. Next, it has listed and analyzed 102 water pollution accidents. The results of our investigation indicate: (1) the number of accidents has been increasing with the urban water supply areas are faced with more and more potential risks in past 20 years, especially in the recent 5 years; (2) the major pollutant is the chemical material and waste water discharge; (3) the major risk source comes from the inland river traffic accidents and the factory pollution events; (4) most of such accidents were reported to have produced serious social influence and economical loss because of scarcity of essential emergency institution and mechanism, especially before 2003; (5) three typical accidents are focused on the serious damage to the social and economic systems, which aroused great concern from the Chinese government and people. This paper argues that the three momentous accidents mentioned in this paper imply the great importance and urgency to establish as soon as possible an emergency system for the state urban water supply resources in the whole country.
Research status-in-situ and key challenges in hydrogen safety
ZHENG Jin-yang;LIU Zi-liang;HUA Zheng-li;GU Chao-hua;WANG Geng;CHEN Lin-xin;ZHANG Yi-wei;ZHU Sheng-yi;HAN Wu-lin;The present paper is aimed at summarizing the research status-in-situ and the key challenges of the hydrogen safety in the hydrogen leakage and diffusion,the hydrogen combustion and explosion,the hydrogen and metallic material compatibility,in addition to the related hydrogen risk assessment. At the same time,the paper has also brought about some suggestions for hydrogen safety measures perfection at home in China so as to confine the hydrogen leakage into a properly controlled sphere.Thus,as a matter of fact,we have also traced and examined the effects of the hydrogen storage pressure,the diameter and the ventilation size,as well as the pressure relief device( PRD) on the pressure peak through experiments. In spite of this,there remain still lots of difficulties to be overcome through study of the complex physical properties of the liquid hydrogen by establishing and verifying the liquid hydrogen leakage model. The combustion regularity of hydrogen in the confined or semi-confined spaces,such as the garage,the tunnels and hydrogen refueling stations,should still be paid great attention,too. Besides,much attention has also been paid to the research of the mechanism of the flame acceleration( FA) and the deflagration-to-detonation transition( DDT) in the confined spaces by the scholars around the world today. Hence,the results of the above research prove that the interaction among the flame,the dominant shock wave and the reflected shock wave should be taken as the main factor to promote the said DDT. What is more,when the material is operated in a hydrogen environment for too long,it may also cause deterioration of the mechanical properties,known as the hydrogen environment embrittlement( HE). Actually,quite a few of tests we can conduct to make out the HE susceptibility of the metallic materials,including the slow strain rate tensile test,the fatigue life test,the fatigue crack growth test and the fracture toughness test. All the above said widely accepted testing methods can be adopted directly to confine the sample under the highpressure hydrogen environment. However,since there is no internationally uniformed hydrogen and material compatibility testing standard for the time being,it wouldn't be conducive to the sharing of the material testing data under the high-pressure hydrogen environment among the countries. All the above said risk assessments have become more and more urgent with the commercial application of the hydrogen refueling stations( HRS) and the hydrogen fuel cell vehicles( HFCV). Such risk assessment methods may include the fast risk ranking( FRR) and the quantitative risk assessment( QRA),the latter of which can not only be used for scientific evaluation of the risk of an accident,but also for the directly application to the formulation of the hydrogen safety distance standards. Besides,some researchers have also been carrying out the QRA studies to the hydrogen leakage accidents in different scenarios,to result in the corresponding QRA methods,though the development of QRA is inseparable from the support of the said software. Therefore,at present,SNL has launched a toolkit,HyRAM,specifically for the hydrogen risk assessment,though the effective data on the hydrogen system structure failure and leakage frequency remain under great need for further proof and rectification.
Comprehensive evaluation method for the railway safety based on the entropy method and the grey relation analysis
FENG Yun-qing;LI Xue-mei;LI Xue-wei;School of Economics and Management,Beijing Jiaotong University;Firstly,this paper has set up two railway safety evaluation systems from the prediction and the result aspects separately based on the analysis of the railway operation safety factors. Secondly,the entropy method has been adopted to calculate the weight of each index that affects the railway safety from the prediction and the result perspective individually. From the weight calculation we can see that the "human factor"is the dominant factor that may lead to railway accidents. Besides,from the perspective of the railway safety consequences,"the damage of railway accidents " factor impacts the most on the railway safety goals. Thirdly,combined with the weight of each index from the prediction perspective,the grey relation grade of the railway safety is calculated using the grey relation analysis during the period from 1985 to 2007 and a railway safety curve was drawn to reflect the trend of the railway safety development. From the above results,it can be concluded that there are three stages in our railway safety development in the past 23 years. The first stage is from 1985 to 1990. In this stage,the railway safety level is low and has a trend of decline because of the low level of technical equipment and management. The second stage is from 1991 to 2000,the level of the railway safety get a great improvement. Although the safety data in some year has fluctuated,the overall trend has improved a lot. The third stage is from 2001 to 2007. Since 2001,the gray correlation degree of the railway safety is over 0. 8 and enters into a steady period. In general,the overall level of China's railway safety obtained an obvious improvement and the overall railway safety in China has reached a high level.