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531.
Walter A. Salas-Zapata Leonardo A. Rios-Osorio Alba L. Trouchon-Osorio 《Sustainability Science》2013,8(4):607-612
Sustainability science is at an early stage of development. Among many other obstacles, there are two prominent issues hindering its advance. There is both a lack of a set of principles for knowledge construction, and a need to implement research to solve real problems. This paper proposes a typology of scientific reflections for meeting these two challenges and contributing to sustainability science development. This typology is made up of four kinds of reflection: practical, instrumental-methodological, theoretical-conceptual, and onto-epistemological. Each kind of reflection is based on a different type of question and gives shape to its respective type of research. 相似文献
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Robert C. Borden Walter J. Beckwith M. Tony Lieberman Naji Akladiss Steve R. Hill 《补救:环境净化治理成本、技术与工艺杂志》2007,17(3):5-19
EOS, or emulsified oil substrate, was used to stimulate anaerobic biodegradation of trichloroethene (TCE) and tetrachloroethene (PCE) at a former Army‐owned manufacturing facility located in the Piedmont area of North Carolina. Previous use of chlorinated solvents at the facility resulted in soil and groundwater impacts. Ten years of active remediation utilizing soil vacuum extraction and air sparging (SVE/AS) were largely ineffective in reducing the TCE/PCE plume. In 2002, the Army authorized preparation of an amended Remedial Action Plan (RAP) to evaluate in situ bioremediation methods to remediate TCE in groundwater. The RAP evaluated eight groundwater remediation technologies and recommended EOS as the preferred bioremediation alternative for the site. Eight wells were drilled within the 100 × 100 feet area believed to be the primary source area for the TCE plume. In a first injection phase, dilute EOS emulsion was injected into half of the wells. Distribution of the carbon substrate through the treatment zone was enhanced by pumping the four wells that were not injected and recirculating the extracted water through the injection wells. The process was repeated in a second phase that reversed the injection/extraction well pairs. Overall, 18,480 pounds of EOS were injected and 163,000 gallons of water were recirculated through the source area. Anaerobic groundwater conditions were observed shortly after injection with a corresponding decrease in both PCE and TCE concentrations. Dissolved oxygen, oxidation‐reduction potential, and sulfate concentrations also decreased after injection, while TCE‐degradation products, ferrous iron, and methane concentrations increased. The reduction in TCE allowed the Army to meet the groundwater remediation goals for the site. Approximately 18 months after injection, eight wells were innoculated with a commercially prepared dechlorinating culture (KB‐1) in an attempt to address lingering cis‐1,2‐dichloroethene (cis‐DCE) and vinyl chloride (VC) that continued to be observed in some wells. Dehalococcoides populations increased slightly post‐bioaugmentation. Both cis‐DCE and VC continue to slowly decrease. © 2007 Wiley Periodicals, Inc. 相似文献
533.
Andjelka Kelic Zachary A. Collier Christopher Brown Walter E. Beyeler Alexander V. Outkin Vanessa N. Vargas Mark A. Ehlen Christopher Judson Ali Zaidi Billy Leung Igor Linkov 《The Environmentalist》2013,33(4):544-560
Increased reliance on the Internet for critical infrastructure and the global nature of supply chains provides an opportunity for adversaries to leverage dependencies and gain access to vital infrastructure. Traditional approaches to assessing risk in the cyber domain, including estimation of impacts, fall short due to uncertainty in how interconnected systems react to cyber attack. This paper describes a method to represent the pathways of disruption propagation, evaluate the macroeconomic impact of cyber threats and aid in selecting among various cybersecurity policies. Based on state of the art agent-based modeling, multicriteria decision analysis, and macroeconomic modeling tools, this framework provides dynamic macroeconomic, demographic and fiscal insights regarding shocks caused by cyber attacks to the regional economy over time. The interlinkage of these models will provide a robust and adaptive system that allows policy makers to evaluate complex issues such as cybersecurity threats and their impacts on the geopolitical, social, environmental, and macroeconomic landscape. 相似文献
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René Rossi Eric Indelicato Walter Bolli 《International journal of occupational safety and ergonomics》2004,10(3):239-245
The aim of this study was to analyse the transfer of steam through different types of textile layers as a function of sample parameters such as thickness and permeability. In order to simulate the human body, a cylinder releasing defined amounts of moisture was also used. The influence of sweating on heat and mass transfer was assessed. The results show that in general impermeable materials offer better protection against hot steam than semi-permeable ones. The transfer of steam depended on the water vapour permeability of the samples, but also on their thermal insulation and their thickness. Increasing the thickness of the samples with a spacer gave a larger increase in protection with the impermeable samples compared to semi-permeable materials. Measurements with pre-wetted samples showed a reduction in steam protection in any case. On the other hand, the measurements with a sweating cylinder showed a beneficial effect of sweating. 相似文献
537.
Radon levels were measured in 119 groundwater samples collected throughout the active volcanic area of Mt. Etna by means of a portable Lucas-type scintillation chamber. The measured activity values range from 1.8 to 52.7 Bq l(-1). About 40% of the samples exceed the maximum contaminant level of 11 Bq l(-1) proposed by the USEPA in 1991. The highest radon levels are measured in the eastern sector of the volcano, which is the seismically most active zone of the volcano. On the contrary the south-western sector, which is both seismically active and a site of intense magmatic degassing, display lower radon levels. This is probably due to the formation of a free gas phase (oversaturation of CO(2)) that strips the radon from the water. Comparison of the data gathered at Mt. Etna with those of other areas indicates that (222)Rn activity in groundwater is positively correlated with both the content of parent elements in the aquifer rocks and the temperature of the geothermal systems that interacts with the sampled aquifers. 相似文献
538.
This paper deals with the decrease in the rate of accident insurance claims in the German mining industry over the last five decades. It intends to show that this process is above all the result of a prevention policy where companies and the body responsible for the legal accident insurance in the mining industry, the Bergbau-Berufsgenossenschaft (BBG), work hand in hand. A system like the German accident insurance scheme, combining prevention, rehabilitation, and compensation, enables successful and modern safety and health measures. 相似文献
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