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1.
Several tools exist for the analysis of the environmental impacts of chains or networks of processes. These relatively simple tools include materials flow accounting (MFA), substance flow analysis (SFA), life-cycle assessment (LCA), energy analysis, and environmentally extended input-output analysis (IOA), all based on fixed input-output relations. They are characterized by the nature of their flow objects, such as products, materials, energy, substances, or money flows, and by their spatial and temporal characteristics. These characteristics are insufficient for their methodological characterization, and sometimes lead to inappropriate use. More clarity is desirable, both for clearer guidance of applications and for a more consistent methodology development. In addition to the nature of the flow object and to spatial and temporal characteristics, another key feature concerns the way in which processes are included in a system to be analyzed.
The inclusion of processes can be done in two fundamentally different ways: according to a full mode of analysis, with the inclusion of all flows and related processes to their full extent as present in a region in a specific period of time; and according to an attribution mode, taking processes into account insofar as these are required for a given social demand, function, or activity, in principle whenever and wherever these processes take place. This distinction, which cuts across families of tools that traditionally belong together, appears to have significant methodological and practical implications. Thus the distinction between the two modes of analysis, however crucial it may be, strengthens the idea of one coherent family of tools for environmental systems analysis.  相似文献   

2.
This article, continuing with the themes of the companion article, expounds the capabilities of input-output techniques as applied to material flows in industrial systems. Material flows are the primary focus because of their role in directly linking natural and industrial systems and thereby being fundamental components of environmental issues in industrial economies. The specific topic in this article concerns several material flow metrics used to characterize system behavior that are derived from the ecological development of input-output techniques; most notable of these metrics are several measures of material cycling and a measure of the number of processes visited by material while in a system. These metrics are shown to be useful in analyzing the state of material flow systems. Further-more, the metrics are shown to be a central link in connecting input-output flow analysis to synthesis (i.e., the process of using measurements of system behavior to design changes to that system). By connecting the flow metrics to both environmental objectives and controllable aspects of flow models, changes to existing flow systems are synthesized to generate improved system behavior. To bring this pair of articles to a close, several limitations of input-output flow analysis are summarized with the goal of stimulating further interest and research.  相似文献   

3.
Input-output mathematics, which allows a modeler to fully consider direct and indirect relationships among conserved flows in a system, has a long history in economics with prominent use dating to Leontief in the 1930s. Nearly all previous industrial applications of input-output analysis have been grounded in the monetary flows of an economy. Here however, because of the central nature of physical flows in the environmental impact of industry, we consider physical flows to be a fundamental component of an industrial economy. Hence, we propose an input-output based approach for modeling physical flows in industry independent of their monetary implications.
In this first part of a two-part article, a framework for using input-output mathematics to model material and energy flows is constructed from a foundation laid by previous research in nutrient and energy cycling in natural ecosystems. The mathematics of input-output flow analysis is presented from an ecological perspective, culminating in two core capabilities: tracing of flows with environs (investigated in this article) and characterizing system behavior with flow metrics (presented in the second article). We assert that environ analysis is an effective means for tracing flows through industrial systems while fully considering direct and indirect flow paths. We explore material flows of aluminum and five other metals in depth using environ analysis in this article.  相似文献   

4.
The Importance of Imports for Household Environmental Impacts   总被引:1,自引:0,他引:1  
A promising way to reduce environmental impacts of consumer expenditure is through the encouragement of more sustainable consumption patterns. Consumers cause environmental impacts both directly, such as by fuel use in personal cars, and indirectly, by paying for the production of consumables. With increased international trade, the indirect environmental impacts are difficult to determine because a portion of the emissions occurs in different geographical regions. Many previous studies have unrealistically assumed that imports are produced using domestic production technology. For countries with diverging technology and energy mixes the likely errors are significant. This study applies a methodology that explicitly includes technology differences to the case of Norwegian households. It is found that a significant portion of pollution is embodied in Norwegian household imports. Further, a disproportionately large amount of pollution is embodied in imports from developing countries. Overall, as in previous studies, we find that mobility and food are most important in terms of household environmental impacts. By analyzing the imports in more detail we find that for some sectors the majority of emissions occur in foreign regions; in particular, this is true for food, business services, clothing, chemicals, furniture, cars, agriculture, textiles, and most manufactured products.  相似文献   

5.
Air sampling was conducted in Waterloo, Canada throughout 1992. Functional relationships between aeromycota and meteorological factors were analysed. The meteorological factors were, in descending order of importance: mean temperature, minimum temperature, maximum temperature, mean wind speed, relative humidity (RH), rain, maximum wind speed and snow. The most important airborne fungal propagules in descending order were: total fungal spores, unidentified Ascomycetes,Cladosporium, Coprinus, unidentified Basidiomycetes,Alternaria and unidentified fungi. Most airborne fungal taxa had highly significant relationship with temperature, butAspergillus/Penicillium, hyphal fragments andEpicoccum did not.Epicoccum and hyphal fragments were positively associated with wind speed. In comparison with other airborne fungal taxa,Leptosphaeria and unidentified Ascomycetes were more closely correlated with rain and RH during the growing season.  相似文献   

6.
Changes in food consumption and related processes have a significant impact on the flow of nitrogen in the environment. This study identifies both flows within the system and emissions to the hydrosphere and atmosphere. A case study of an average inhabitant of the city of Linköping, Sweden, covers the years 1870, 1900, 1950, and 2000 and includes changes in food consumption and processing, agricultural production, and organic waste handling practices. Emissions to the hydrosphere from organic waste handling increased from 0.57 kilograms of nitrogen per capita per year (kg N/cap per year) to 3.1 kg N/cap per year, whereas the total flow of nitrogen to waste deposits grew from a negligible amount to 1.7 kg N/cap per year. The largest flow of nitrogen during the entire period came from fodder. The input of chemical fertilizer rose gradually to a high level of 15 kg N/cap per year in the year 2000. The total load per capita disposed of to the environment decreased during these 130 years by about 30%.  相似文献   

7.
张炳  黄和平  毕军 《生态学报》2009,29(5):2473-2480
区域生态效率(eco-efficiency)评价是考量区域可持发展的重要内容.基于物质流分析(material flow analysis, MFA)构建区域生态效率评价指标体系,并将污染物排放作为一种非期望输入引入到数据包络分析(data envelopment analysis, DEA)模型中,以江苏省(1990~2005年)为例进行生态效率分析评价.结果表明,江苏省的区域生态效率在1990~2005年期间呈现逐步上升的趋势.但是,同期的总物质投入(total material input, TMI)、物质需求总量(total material requirement, TMR)和污染物排放量也呈上升趋势.因此,江苏省社会经济发展和环境影响总体上呈现"弱脱钩(weak de-link)".  相似文献   

8.
通过测定阈值和频谱分析,比较了正常和卡那霉素中毒后豚鼠听觉脑干反应(ABR)及频率跟随反应(FFR)的特性.正常FFR的非线性随刺激频率的减低而增加,表现为高次谐波的出现.从频谱中基频成分的峰很容易识别FFR阈值.卡那霉素作用后,高频FFR首先受到影响,波幅下降,阈值显著升高.低频FFR受到影响较小.同一动物ABR阈值尚未变化时高频FFR的基频峰值已下降,乃至消失.实验结果表明FFR对耳毒性药物中毒反应由于其包含有频率特性比ABR更灵敏,更便于定量分析.  相似文献   

9.
Abstract

A therapeutic rationale is proposed by selectively targeting tyrosine kinase 2 (TYK 2) to obtain potent TYK 2 inhibitors by molecular modeling studies. In the present study, we have taken tyrosine kinase (TYK 2) inhibitors and carried out molecular docking, 3?D quantitative structure–activity relationship (3D-QSAR) analysis and molecular dynamics (MD). Based on the 3D-QSAR results thirteen new compounds (R-1 to R-13) were designed and synthesized in good yields. The synthesized molecules were evaluated for their in vitro anticancer activity against LnCap and A549 cell lines. The molecules R-1, R-3, R-5, R-7, and R-10 exhibited considerable anti cancer activity.  相似文献   

10.
We present an input-output analysis of the life-cycle labor, land, and greenhouse gas (GHG) requirements of alternative options for three case studies: investing money in a new vehicle versus in repairs of an existing vehicle (labor), passenger transport modes for a trip between Sydney and Melbourne (land use), and renewable electricity generation (GHG emissions). These case studies were chosen to demonstrate the possibility of rank crossovers in life-cycle inventory (LCI) results as system boundaries are expanded and upstream production inputs are taken into account. They demonstrate that differential convergence can cause crossovers in the ranking of inventories for alternative functional units occurring at second-and higher-order upstream production layers. These production layers are often excluded in conventional process-type life-cycle assessment (LCA) by the delineation of a finite system boundary, leading to a systematic truncation error within the LCI. The exclusion of higher-order upstream inputs can be responsible for ranking crossovers going unnoticed. In this case, an incomplete conventional process-type LCA of two alternative options can result in preferences and recommendations to decision makers that are different from preferences and recommendations concluded from a complete hybrid input-output-based assessment. Therefore, the need to avoid misleading effects on the ranking of alternative functional units due to differential convergence supports the practice of hybrid input-output-based LCA techniques.  相似文献   

11.
The molecular conformation of three newly synthesized, sterically hindered aryl derivatives of five-membered nitrogen-containing heterocyclicortho-analogs of POPOP were studied by X-ray analysis and vibrational spectroscopy. It was shown that molecules of the compounds in the crystalline state and in solution are non-planar and asymmetric.  相似文献   

12.
对二龄棉铃虫Heliothisarmigera(Hübner)幼虫血淋巴的二种样品(去血细胞和未去血细胞)中的干物重、含水量、灰分、蛋白质、总糖、还原糖、总脂、胆固醇、维生素C的含量,分别进行了定量分析,对未去血细胞的血淋巴进行了氨基酸测定;同时,对蛋白质组份、脂类组份也进行了定性分析  相似文献   

13.
A number of potential explanatory variables for the stocks and flows of copper and zinc in contemporary technological societies are co-analyzed with the tools of exploratory data analysis. A one-year analysis (circa 1994) is performed for 50 countries that comprise essentially all anthropogenic stocks and flows of the two metals. The results show that (1) The key explanatory variable for metal use is gross domestic product (GDP) per capita (purchasing power parity, PPP). By itself, GDP explains between one-third and one-half of the variance of per capita copper and zinc use. Other variables that were significantly correlated with copper and zinc use included stock of passenger cars and television sets (per 1, 000 people); two infrastructure variables, wired telephone connections, urban population, and value added inmanufacturing. The results do not provide evidence supporting the Kuznets curve hypothesis for these metals. (2) Metal use per capita can be estimated using multiple regression equations. For copper, the natural logarithm of use is related to the explanatory variables GDP (PPP), value added in manufacturing, and urban population. This model explains 80% of the variance among the different countries (r2= 0.79). The natural logarithm of zinc use is related to GDP (PPP) and value added in manufacturing with an r2 of 0.75; (3) For both metals, rates of metal fabrication, use, net addition to stock, and discard in low-and high-income countries differ significantly from each other. Our statistical analyses thus provide a basis for estimating the potential development of metal use, net addition to stock, and discard, using data on explanatory variables that are available at the international level.  相似文献   

14.
玉米过氧化物还原蛋白BAS1的原核表达及其功能研究   总被引:1,自引:0,他引:1  
植物过氧化物还原蛋白BAS1是巯基依赖的过氧化物酶,通过催化的Cys残基还原过氧化氢,依赖NADPH的叶绿体硫氧还蛋白还原酶保持BAS1的还原态。玉米含有两种BAS1:2-Cys PrxA和2-Cys PrxB。利用RT-PCR方法从玉米幼叶中克隆了编码成熟2-Cys PrxA的基因,并将蛋白Cys34残基突变成Ser34。SDS-PAGE显示纯化的野生型和突变体蛋白为一条主带,分子量约为23kDa;体外蛋白结合实验表明纯化的叶绿体硫氧还蛋白还原酶通过分子间二硫键结合纯化的2Cys PrxA的C34S突变体,非还原SDS-PAGE显示纯化的野生型2Cys PrxA含有分子间二硫键组成的二体,而纯化的C34S突变体呈现单体,巯基专一性标记化合物AMS修饰及活性分析表明纯化的BAS1还原态是催化还原过氧化氢所所必须的,它由硫氧还蛋白还原酶及其辅酶NADPH所催化。  相似文献   

15.
16.
Melittis melissophyllum L., a medicinal plant currently used in the folk medicine, was analyzed for the content of flavonoid compounds. The plants were collected in two locations in Poland in May and September. MeOH Extracts from the leaves and flowers (separately) were analyzed by HPLC‐DAD. Eight compounds were identified in all the samples and quantitatively analyzed as cinaroside (=luteolin 7‐O‐glucoside), rutin, myricetin, quercitrin, quercetin, luteolin, kaempferol, and apigenin. M. melissophyllum accumulated the highest total amounts of flavonoids in May (flowers: from 258 to 271 mg/100 g dry weight (dw); leaves: from 143 to 155 mg/100 g dw) and significantly lower ones in September (leaves: from 83 to 92 mg/100 g dw). The main compound was cinaroside (May: up to 249 mg/100 g dw; September: up to 43 mg/100 g dw). Advanced multivariate statistical techniques (cluster analysis (CA) and principal component analysis (PCA)) were used to characterize the sample populations and to analyze the data. We report, for the first time, the results of the quantitative analysis of M. melissophyllum flavonoids and seasonal changes in their accumulation. Our results show that the time of harvesting has a significant influence on the flavonoid content in M. melissophyllum, while the geographical location does not have such an effect.  相似文献   

17.
18.
This article presents an assessment of energy inputs of the European Union (the 15 countries before the 2004 enlargement, abbreviated EU‐15) for the period 1970–2001 and the United States for 1980–2000. The data are based on an energy flow analysis (EFA) that evaluates socioeconomic energy flows in a way that is conceptually consistent with current materials flow analysis (MFA) methods. EFA allows assessment of the total amount of energy required by a national economy; it yields measures of the size of economic systems in biophysical units. In contrast to conventional energy balances, which only include technically used energy, EFA also accounts for socioeconomic inputs of biomass; that is, it also considers food, feed, wood and other materials of biological origin. The energy flow accounts presented in this article do not include embodied energy. Energy flow analyses are relevant for comparisons across modes of subsistence (e.g., agrarian and industrial society) and also to detect interrelations between energy utilization and land use. In the EU‐15, domestic energy consumption (DEC = apparent consumption = domestic extraction plus import minus export) grew from 60 exajoules per year (1 EJ = 1018 J) in 1970 to 79 EJ/yr in 2001, thus exceeding its territory's net primary production (NPP, a measure of the energy throughput of ecosystems). In the United States, DEC increased from 102 EJ/yr in 1980 to 125 EJ/yr in 2000 and was thus slightly smaller than its NPP. Taken together, the EU‐15 and the United States accounted for about 38% of global technical energy use, 31% of humanity's energetic metabolism, but only 10% of global terrestrial NPP and 11% of world population in the early 1990s. Per capita DEC of the United States is more than twice that of the EU‐15. Calculated according to EFA methods, energy input in the EU and the United States was between one‐fifth and one‐third above the corresponding value reported in conventional energy balances. The article discusses implications of these results for sustainability, as well as future research needs.  相似文献   

19.
Combined MFA-LCA for Analysis of Wastewater Pipeline Networks   总被引:1,自引:0,他引:1  
Oslo's wastewater pipeline network has an aging stock of concrete, steel, and polyvinyl chloride (PVC) pipelines, which calls for a good portion of expenditures to be directed toward maintenance and investments in rehabilitation. The stock, as it is in 2008, is a direct consequence of the influx of pipelines of different sizes, lengths, and materials of construction into the system over the years. A material flow analysis (MFA) facilitates an analysis of the environmental impacts associated with the manufacture, installation, operation, maintenance, rehabilitation, and retirement of the pipelines. The forecast of the future flows of materials—which, again, is highly interlinked with the historic flows—provides insight into the likely future environmental impacts. This will enable decision makers keen on alleviating such impacts to think along the lines of eco-friendlier processes and technologies or simply different ways of doing business. Needless to say, the operation and maintenance phase accounts for the major bulk of emissions and calls for energy-efficient approaches to this phase of the life cycle, even as manufacturers strive to make their processes energy-efficient and attempt to include captive renewable energy in their total energy consumption. This article focuses on the life cycle greenhouse gas emissions associated with the wastewater pipeline network in the city of Oslo.  相似文献   

20.
综述了各种脱落酸产生真菌的生物学特征及其不同的生物合成代谢途径,并对脱落酸的定量分析技术作了简要介绍。  相似文献   

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