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A teacher of ours used to say, “Like ice in a fire, something for nothing you will never acquire”, which is a poetic equivalent of “there is no such a thing as a free lunch”. Human economies are dependent on high quality fossil fuels and will likely continue depending on them for some time to come. Value of a resource is not only what one pays for it, or what can be extracted from it, but also value can be attributed to the “effort” required in its production. In this analysis we apply the emergy synthesis method to evaluate the work invested by the geobiosphere to generate the global storages of fossil energy resources. The upgrading of raw resources to secondary fuels is also evaluated. The analysis relies on published estimates of historic, global net primary production (NPP) on land and oceans, published preservation and conversion factors of organic matter, and assessments of the present total global storages of coal, petroleum, and natural gas. Results show that the production of coal resources over geologic time required between 6.63E4 (±0.51E4) seJ/J and 9.71E4 (±0.79E4) seJ/J, while, oil and natural gas resources required about 1.48E5 (±0.07 E5) seJ/J and 1.70E5 (±0.06E5) seJ/J, respectively. These values are between 1.5 and 2.5 times larger than previous estimates and acknowledge a far greater power of fossil fuels in driving and shaping modern society. 相似文献
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介绍荆门分公司50kt/a酸性气干法制硫酸装置的工艺设计特点、开车及运行情况,指出装置在运行过程中遇到的问题和解决方法。 相似文献
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Dai Tiejun 《Resources, Conservation and Recycling》2011,55(8):760-771
An iron resource efficiency is proposed to define a measure of the natural iron resources saved in the steel manufacturing process. A simplified iron flow diagram is presented for the steel manufacturing process. The influences of various deviations in iron flow from the simplified iron flow diagram on iron resource efficiency are analyzed. The relationships between iron resource efficiency of unit processes and the final product are also discussed. As an example, data from a steel plant are used to analyze the influence of iron flow on its iron resource efficiency of finial product in the steel manufacturing process, the influence of iron resource efficiency of unit process on iron resource efficiency of the final product, and give some measures to improve the iron resource efficiency of the steel manufacturing process. 相似文献
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沈阳市土地生态适宜性初步评价 总被引:10,自引:0,他引:10
主要通过运用生态学、土壤学、环境科学、系统科学和计算机科学的理论、手段与方法。根据行政区划和自然地理条件,对沈阳市土地进行评价单元的划分,运用特尔菲法对预选评价指标集进行筛选,建立评价指标体系并确定各评价因子的权重值,通过加权指数和法计算各评价单元的综合评价值,确立土地生态适宜性分级标准,划分沈阳市土地生态适宜性分区,确定划分区域的土地用途,建立沈阳市土地利用适宜生态发展的模式,为沈阳市土地利用规划提供科学依据。 相似文献
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In this study, the trends in paracetamol poisoning were examined over more than a decade in Cardiff and compared with patterns for other substances taken in overdose. All data concerned patients aged 14 years and over of both genders, who were referred to the Cardiff Poisons Treatment Unit between 1989 and 2002. The Chi-squared test for trend was used. During the 14-year study period, there were 18,834 admissions to the hospital, involving poisoning either with pure paracetamol or paracetamol in combination with other drugs (37%, N = 6975), and the proportion of admissions with paracetamol poisoning increased from 36% in 1989 to 44% in 2002. Paracetamol was the second most common drug associated with admissions related to poisoning to the Cardiff Poisons Treatment Unit (37%), after alcohol (48%). Thus, paracetamol poisoning remains a major public health concern in the UK. 相似文献
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Environmental Impact Evaluation Model for Industrial Processes 总被引:4,自引:0,他引:4
This paper proposes a model to evaluate the environmental impact of manufacturing processes. This model uses the potency factor approach to classify environmental impacts into five ecological health impact groups and uses their toxicological, cancer, and physical effects as the bases to rate the seven groups of human health impacts. The environmental impacts in each impact group are reported, and their hazard scores on ecological and human health are determined. The model also generates a single score for the overall environmental impacts of a process. This single score system helps to identify, among all the viable processes, which is the most environmentally friendly process. This model can serve as a tool to highlight the potential environmental hazards of process operations and to provide information about environmental performance for decision making. The model has been developed into a computer software program, Environmental Impact Evaluation System, and is demonstrated by using the processes employed for the manufacture of paper bags. 相似文献
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Lynne M. Rochette Author Vitae Kristen A. Conner Author Vitae Author Vitae 《Journal of Safety Research》2009,40(5):353-358