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901.
902.
Atsushi Terazono Yuichi Moriguchi Shin-ichi Sakai Hiroshi Takatsuki 《Journal of Material Cycles and Waste Management》2000,2(2):80-88
This study evaluated the environmental impacts of sprayed-on asbestos, which had been used as insulation material in buildings,
from multiple perspectives, mainly at the disposal stage. The health risks from asbestos emission and energy consumption were
estimated. Two disposal scenarios were assumed for the asbestos: melting for reduced-risk disposal and ordinary packaging/landfilling.
We estimated the asbestos emission and health risk in the case of packaging/landfilling, assuming uncontrolled management
of the landfill site. A difficulty with introducing health-risk concepts into life cycle assessment (LCA) is the pulse–flux
problem, which is discussed in the light of these estimations. In order to solve this problem, we proposed a method using
a conversion factor representing exposure-dose/emission, and showed that emission could be converted into health risk. We
also estimated the energy consumption for melting asbestos in the disposal stage, which can decrease the health risk. If we
consider the energy consumption for the life cycle of asbestos, only a little energy is required for melting, compared with
the large amount of energy saved in the use stage owing to the insulating effect of the asbestos. The trade-off relationship
between health risk and energy consumption for the disposal scenarios indicated the need for weighting methods to handle trade-offs
such as this.
Received: July 2, 1998 / Accepted: December 20, 1999 相似文献
903.
将时间因素和生物碳通量纳入林产品生命周期碳足迹评估,通过动态生命周期分析法(Dynamic Life Cycle Assessment,DLCA),确定林产品生产、使用和废弃阶段替代化石能源的净温室气体减排和对森林碳损失的净弥补时间。首先,建立温室气体排放和封存的动态生命周期清单,评估刨花板全生命周期的碳动态和碳足迹;其次,根据ISO 14040和PAS 2050标准提供的静态生命周期分析法分别核算包含与不包含碳储计算的碳足迹,量化时间因素和生物碳通量对于碳足迹结果差异的影响程度;最后,对比自然生长状态的森林碳汇情境,评估刨花板使用和废弃阶段替代化石燃料实现净气候减排所需的时间。研究表明:①时间因素和生物碳通量核算对碳足迹结果影响较大(223.34%),忽视时间因素会低估刨花板的减排贡献(18.98%)。②动态生命周期分析法可准确评估生物碳和温室气体排放的时间问题,但对时间范围非常敏感(75.19%和113.25%)。③生产、使用林产品以及林产品对化石能源的替代是实现长期气候减排的有效方式,在100a的时间范围能够弥补因森林砍伐造成的碳损失,从而实现碳中性。 相似文献
904.
N. Pajunen L. Rintala J. Aromaa K. Heiskanen 《International Journal of Sustainable Engineering》2016,9(2):93-106
Natural resources and raw materials such as metals and minerals are often taken for granted in today’s society. Without them, the offerings of an enormous variety of modern conveniences, including computers and mobile phones, would not be possible. The production of these everyday items depends on a secure, sustainable, and reliable supply of critical raw materials. In addition, product development also requires new hybrid materials when targeting lightweight structures, etc. However, the mandatory recyclability of new products or materials is not obligatory or even prevailing practice in present manufacturing business. Therefore, the main research question in this article is: “how to solve the challenge of recycling in industrial system?” In this article, a comprehensive approach to recycling based on the findings of research projects is presented. Simplified, this involves moving the challenge from the end of the product’s life cycle to the beginning, to the design or even to material development phases. Life cycle and system thinking and material know-how in the design phase are found to be essential elements of a new approach to recycling. This approach stems from the material development and market economy perspectives. Furthermore, the vulnerability of the industrial system to create uncertainty to recycling is also demonstrated. 相似文献
905.
The cement industry is one of the most energy-intensive industries consuming 4 GJ/ton of cement, i.e. 12–15% of the energy use in total industry. Energy cost accounts for 30% of the total cost of cement production. Seventy-five per cent of this energy is due to the thermal energy for clinker production. It is also found that 35% of this supplied thermal energy is lost in flue gas streams. Most modern kilns use pet coke or coal as their primary fuel. Instead, the municipal waste in landfills offer a cheap source of energy and reduce the environmental effects of dumping solid waste. The calcination and drying processes and the kiln need large quantities of thermal energy. About 40% of the total energy input is lost in the hot flue gases and cooling the stack plus the kiln shell. Hence, it is suitable to use an organic Rankine cycle (ORC) to recover the exhaust energy from the kiln. Alternatively, a 15 MW gas turbine engine combined with a steam turbine could be utilized. It was found that ORC produces 5 MW with a capital cost recovery period of 1.26 years. However, the gas turbine combined system produces 21.45 MW with a maximum recovery period of 2.66 years. 相似文献
906.
907.
The Influence of mixed and pure working fluids on the performance of organic Rankine cycles (ORCs) is discussed. Specifically, the performance of mixed and pure working fluids is analyzed based on certain characteristics of low-temperature heat source and heat sink. A method of selecting binary zeotropic mixed working fluids that match with different heat sinks is introduced. Thermodynamic processes of ORCs for various heat sources are simulated in Matlab. The performance characteristics of pure and mixed working fluids are compared under different inlet temperatures and temperature gradients of sensible heat sources. The results demonstrate that when the initial temperature of a heat source is lower and its temperature gradient is higher, and the temperature gradient of the heat sink is higher, mixed working fluids have better performance than pure working fluids. However, for the opposite heat source and heat sink situations, pure working fluids perform better. Mixtures with low critical temperature components exhibit the best performance among all working fluids when the temperature gradient of the heat source is large. The analysis also shows that introduction of a recuperator may reduce the cycle efficiency when the heat source temperature is low and the temperature gradient of the heat source is large. 相似文献
908.
Humans are primarily exposed to fluoride (Fl), a widespread environmental pollutant, via contaminated drinking water and foodstuffs. The aim of this study was to examine whether sodium fluoride (NaF) exerted cytotoxic effects in human hepatocarcinoma (HepG2) cells. HepG2 cells were incubated with different concentrations of NaF and reactive oxygen species (ROS) levels, cell cycle, apoptosis, and DNA damage determined. Concentration-dependent studies showed that exposure to HepG2 cells with different concentrations of NaF for 24 hr significantly decreased cell viability and intracellular antioxidant capacity. Furthermore, NaF exposure increased lipid peroxidation levels and accumulation of intracellular ROS; and lowered antioxidant glutathione concentrations. In addition to oxidative impairments, NaF treatment enhanced HepG2 cell death via apoptotic pathway as evidenced by DNA fragmentation and cell cycle arrest. Sodium fluoride treatment unregulated p53 level, and Bax and Bcl2 expression. Diminished cell viability and changes in cell cycle accompanied a rise in p53 expression. 相似文献
909.
气相色谱法测定废水中N,N─二甲基甲酰胺 总被引:1,自引:0,他引:1
用气相色谱仪氢焰检测器,PEG20M毛细管柱测定废水中的N,N二甲基甲酰胺(DMF),结果表明与分光光度法基本一致 相似文献
910.
A Hydrologic Drying Bias in Water‐Resource Impact Analyses of Anthropogenic Climate Change
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P.C.D. Milly Krista A. Dunne 《Journal of the American Water Resources Association》2017,53(4):822-838
For water‐resource planning, sensitivity of freshwater availability to anthropogenic climate change (ACC) often is analyzed with “offline” hydrologic models that use precipitation and potential evapotranspiration (Ep) as inputs. Because Ep is not a climate‐model output, an intermediary model of Ep must be introduced to connect the climate model to the hydrologic model. Several Ep methods are used. The suitability of each can be assessed by noting a credible Ep method for offline analyses should be able to reproduce climate models’ ACC‐driven changes in actual evapotranspiration in regions and seasons of negligible water stress (Ew). We quantified this ability for seven commonly used Ep methods and for a simple proportionality with available energy (“energy‐only” method). With the exception of the energy‐only method, all methods tend to overestimate substantially the increase in Ep associated with ACC. In an offline hydrologic model, the Ep‐change biases produce excessive increases in actual evapotranspiration (E), whether the system experiences water stress or not, and thence strong negative biases in runoff change, as compared to hydrologic fluxes in the driving climate models. The runoff biases are comparable in magnitude to the ACC‐induced runoff changes themselves. These results suggest future hydrologic drying (wetting) trends likely are being systematically and substantially overestimated (underestimated) in many water‐resource impact analyses. 相似文献