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11.
Anil Baral 《Ecological modelling》2010,221(15):1807-1818
A commonly encountered challenge in emergy analysis is the lack of transformity data for many economic products and services. To overcome this challenge, emergy analysts approximate the emergy input from the economy via a single emergy/money ratio for the country and the monetary price of economic inputs. This amounts to assuming homogeneity in the entire economy, and can introduce serious uncertainties in the results. This paper proposes and demonstrates the use of a thermodynamically augmented economic input-output model of the US economy for obtaining sector-specific emergy to money ratios that can be used instead of a single ratio. These ratios at the economy scale are more accurate than a single economy-wide emergy/money ratio, and can be obtained quickly for hundreds of economic products and services. Comparing sector-specific emergy/money ratios with those from conventional emergy studies indicates that the input-output model can provide reasonable estimates of transformities at least as a stop-gap measure until more detailed analysis is completed. A hybrid approach to emergy analysis is introduced and compared with conventional emergy analysis using life cycles of corn ethanol and gasoline as examples. Emergy and transformity data from the hybrid approach are similar to those from conventional emergy analysis, indicating the usefulness of the proposed approach. In addition, this work proposes the metric of return on emergy investment for assessing product alternatives with the same utility such as transportation fuels. The proposed approach and data may be used easily via web-based software.  相似文献   
12.
Balanus amphitrite, an acorn barnacle, is distinctly euryhaline, eurythermal and a dominant fouling organism found in warm and temperate waters throughout the world. In this study, the influence of temperature and food concentration on the reproductive biology of this species collected from a tropical habitat was evaluated. Adult barnacles were maintained at 20, 25 and 30°C temperatures at different concentrations of food (50, 100, 150 and 200 Artemia ind−1 day−1). In this previously believed obligatory cross-fertilizing hermaphrodite, self-fertilization was observed. The rise in temperature from 20 to 30°C resulted in a longer interbreeding interval (6–7 days, 200 Artemia ind−1 day−1; 11–13 days, 50 Artemia ind−1 day−1). Computed carbon gained through feeding during the interbreeding interval indicated an inverse relationship to the temperature. At 20°C, although a greater amount of carbon was gained through feeding, the numbers of larvae produced were fivefold less when compared to those raised at 30°C. At 20°C, 2.3 μg C was required to produce a single larva, whereas at 30°C it was 0.4 μg C. A rise in rearing temperature also influenced the molting rate positively. Observations on temporal variation in the gonad development of this species in a tropical coastal environment influenced by the monsoons indicated gonad development to be positively related to chlorophyll a concentration.  相似文献   
13.
This study examines the relationship between air pollution, social deprivation and health in the city of Leeds, UK under a baseline and three distance-based road user charging (RUC) scenarios set at 2 pence, 10 pence and 20 pence/km. Through application of a series of linked models of traffic, emission and pollutant dispersion, air quality was modelled in response to RUC scenarios. The pollutant modelled were NO(2), PM(10), CO, benzene and 1,3-butadiene, though results of NO(2) are used in this study. The RUC scenarios were compared with the 'base' scenario, all set for the year 2005. The RUC initiatives result in the differences in ambient concentrations of NO(2). The study correlates NO(2) concentrations with derived indices of social deprivation and health. The study concludes that positive but weak relationship exists between air quality and social deprivation, and indicates that deprived population groups are disproportionately exposed to higher NO(2) levels. The relationship between air quality and health status of the population is weak. There is a strong relationship between social deprivation and health status of the population. The study concludes that RUC scenarios result in reducing disparity between affluent and deprived populations.  相似文献   
14.
Conventional soil-aquifer treatment (SAT) systems comprise of natural lithological sections up to the depth of zone of saturation or dried aquifers, which through geopurification process recharge the aquifers using domestic or industrial wastewaters. Such SAT systems have low infiltration capacity and frequently face the clogging problems, which causes environment hazards in the local areas. Under this study, three artificial set of lithologies (Lithology I, Lithology II, and Lithology III) were generated without using soil. Each one meter set of lithology was generated within a transparent cylindrical pipe of diameter 15 cm. Each lithology was equipped with nonwoven geotextile and geogrid material at different levels and comprises of coarse aggregate, fine aggregate, coarse sand, medium sand, and fine sand. Use of geotextile material within the artificial lithology shows approximately 8–10 times enhancement in the filtration capacity of the tested lithologies. Municipal wastewater (after primary treatment) was used to test the Lithologies I, II, and III. Between 100–200 l of wastewater was passed through each set of lithology everyday for seven days. Different water quality parameters such as pH, turbidity, electrical conductivity, fluoride, total suspended solids, biological oxygen demand, dissolve oxygen and carbon oxygen demand, chloride, and manganese were analyzed before and after passing through the lithologies everyday. One meter set of artificial lithologies have successfully reduced the concentration of measured water quality parameters between 60 and 93 %, without clogging. Lithology III equipped with superficial fine sand layer and two set of nonwoven geotextile has successfully removed 70–93 % concentration of wastewater. This study aims to demonstrate that a SAT system equipped with geotextile and without soil is more effective then the prevailing SAT systems. Study also proposed designs of SAT systems, which can be formed at unfavorable sites using abundant dry wells in which artificial set of lithologies can be used.  相似文献   
15.
Environmental Science and Pollution Research - Strategic valorization of readily available sugarcane bagasse (SB) is very important for waste management and sustainable biorefinery. Conventional SB...  相似文献   
16.
The formation of ultrafine particles, their growth, and associated characteristic features has been studied during new particle formation events over a high-altitude station of the Western Ghats during the 2014 post-monsoon season. Most of the events were observed during noon time where particle bursts in the nucleation-mode size range from 5 to 25 nm followed by sustained growth in size. This phenomenon persists for ~4–8 h with a growth rate of 1–2 nm h1. Peak concentrations of nucleation-mode particles during the event generally vary from 2300 to 5000 cm3. The mean growth rate is 1.4 ± 0.42 nm h1, particle formation rate is 1.14 ± 0.22 cm3 s1, coagulation sink is 0.35 ± 0.22 cm3 s1, and condensational sink is 15.4 ± 2.6?×?103 s1. All these values are comparable with earlier results from Indian region. Comparison of size-segregated particle number concentration during days of new particle formation events and those without new particle formation were carried out showing a distinct variation in nucleation and Aitken mode with least variability associated with the accumulation mode.  相似文献   
17.
In the present study, we have investigated the influence of polymorphism of GSTM1 and GSTT1 genes and confounding factors such as age, sex, exposure duration and consumption habits on cytogenetic biomarkers. Frequency of sister chromatid exchanges (SCEs), high frequency cell (HFC) and cytokinesis blocked micronuclei (CBMN) were evaluated in peripheral blood lymphocytes of 115 occupationally exposed road construction workers and 105 unexposed individuals. The distribution of null and positive genotypes of glutathione-S transferase gene was evaluated by multiplex PCR among control and exposed subjects. An increased frequency of CBMN (7.03 ± 2.08); SCE (6.95 ± 1.76) and HFC (6.28 ± 1.69) were found in exposed subjects when compared to referent (CBMN - 3.35 ± 1.10; SCE - 4.13 ± 1.30 and HFC - 3.98 ± 1.56). These results were found statistically significant at p < 0.05. When the effect of confounding factors on the frequency of studied biomarkers was evaluated, a strong positive interaction was found. The individuals having GSTM1 and GSTT1 null genotypes had higher frequency of CBMN, SCE and HFC. The association between GSTM1 and GSTT1 genotypes and studied biomarkers was found statistically significant at p < 0.05. Our findings suggest that individuals having null type of GST are more susceptible to cytogenetic damage by occupational exposure regardless of confounding factors. There is a significant effect of polymorphism of these genes on cytogenetic biomarkers which are considered as early effects of genotoxic carcinogens.  相似文献   
18.
High population density, inadequate infrastructure and low adaptive capacity have made the urban population of Bangladesh highly vulnerable to climate change. Trends in climate and climate-related extreme events in five major cities have been analyzed in this paper to decipher the variability and ongoing changes in urban Bangladesh. An analysis of 55 years (1958–2012) of daily rainfall and temperature data using nonparametric statistical methods shows a significant increase in annual and seasonal mean daily maximum and minimum temperatures in all five cities. A significant increase in climate-related extreme events, such as heavy rainfall events (>20 mm), hot days (>32 °C) and hot nights (>25 °C), is also observed. Climate model results suggest that these trends will continue through the twenty-first century. Vulnerability of urban livelihoods and physical structures to climate change is estimated by considering certainty and timing of impacts. It has been predicted that public health and urban infrastructures, viz. water and power supply, would be the imminent affected sectors in the urban areas of Bangladesh. Adaptation measures that can be adopted to mitigate the negative impacts of climate change are also discussed.  相似文献   
19.
Stakeholder analysis means many things to different people. Various methods and approaches have been developed in different fields for different purposes, leading to confusion over the concept and practice of stakeholder analysis. This paper asks how and why stakeholder analysis should be conducted for participatory natural resource management research. This is achieved by reviewing the development of stakeholder analysis in business management, development and natural resource management. The normative and instrumental theoretical basis for stakeholder analysis is discussed, and a stakeholder analysis typology is proposed. This consists of methods for: i) identifying stakeholders; ii) differentiating between and categorising stakeholders; and iii) investigating relationships between stakeholders. The range of methods that can be used to carry out each type of analysis is reviewed. These methods and approaches are then illustrated through a series of case studies funded through the Rural Economy and Land Use (RELU) programme. These case studies show the wide range of participatory and non-participatory methods that can be used, and discuss some of the challenges and limitations of existing methods for stakeholder analysis. The case studies also propose new tools and combinations of methods that can more effectively identify and categorise stakeholders and help understand their inter-relationships.  相似文献   
20.
A number of microorganisms were isolated from sewage. Biochemical Oxygen Demand (BOD-5 day) analysis was carried out by individual pure cultures. The cultures giving higher or equal BOD values as compared to reference GGA solution were selected for the formulation of a defined mixed microbial consortium. This microbial consortium was co-immobilized on calcium-alginate beads. Four synthetic and six industrial samples were tested for BOD by using immobilized beads as well as sewage as source of seeding materials. BOD values obtained with beads for all the synthetic as well as industrial samples were fairly comparable with those obtained with sewage. Reusability of prepared microbial beads was also checked with different synthetic and industrial samples and was compared with reference GGA solution. The same microbial beads can be reused three times for different BOD-5 day estimations. It is recommended that immobilized microbial beads can be used as a ready-to-use seeding material for BOD analysis.  相似文献   
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