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231.
Urban areas in developing countries are facing vast environmental problems as a result of rapid urbanization and industrialization. Of major concern is the contamination of soils which are increasingly becoming sinks for environmental pollutants. However, to date only little is known about the pollution in the megalopolises of developing countries. The aim of this study was to assess the contamination and potential sources of metals, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in the urban environment of Addis Ababa, the capital of Ethiopia. The investigation revealed the presence of most of the analyzed pollutants in soil and sediment samples with total concentrations (dry wt) of PAHs ranging from 186 to 3150?µg?kg?1, PCBs from 0.4 to 19?µg?kg?1, Cu from 14 to 173?mg?kg?1, Zn from 36 to 440?mg?kg?1, Pb from 9 to 700?mg?kg?1, and Ni from 16 to 72?mg?kg?1. In addition, polyaromatic sulfur heterocycles, typical for oil and petrol residues, were detected in several soil samples. Source identification approaches revealed that Pb, Zn, and Cu are most likely derived from pyrolytic sources, with elevated values in samples related to waste combustion and traffic emissions. Ni is most probably of geogenic origin. For PCBs it is indicated that they are derived from a single source. However, correlations with technical PCB mixtures were inconsistent. PAHs originate from the combustion of biomass, vehicular exhausts, and petrogenic sources. 相似文献
232.
Firms select different governance types (e.g. internalisation, outsourcing or collaboration) for corporate social responsibility (CSR) activities. This paper examined how the choice of CSR governance type is influenced by social factors and organisational experiences and how changes in these factors affect the governance choice. These questions are especially meaningful in the context of developing countries with weak institutional environments and recent social change. With the unique phenomenon that is not readily explainable in terms of the extant theoretical groundwork on CSR governance choice, a case study of a South Korean forestry campaign by Yuhan-Kimberly was analysed. It was found that social circumstances triggered Yuhan-Kimberly's initiation of forestry projects, but the absence of social infrastructure limited the choice of governance type early on. Lack of experience also constrained the governance choice. Over time, environmental change and the accumulation of organisational knowledge caused the choice of governance to evolve. This study contributes to the CSR governance choice literature by exploring social and organisational determinants other than economic efficiency and by applying a dynamic perspective. 相似文献
233.
The benefits of indigenous knowledge within disaster risk reduction are gradually being acknowledged and identified. However, despite this acknowledgement there continues to be a gap in reaching the right people with the correct strategies for disaster risk reduction. This paper identifies the need for a specific framework identifying how indigenous and western knowledge may be combined to mitigate against the intrinsic effects of environmental processes and therefore reduce the vulnerability of rural indigenous communities in small island developing states (SIDS) to environmental hazards. This involves a review of the impacts of environmental processes and their intrinsic effects upon rural indigenous communities in SIDS and how indigenous knowledge has contributed to their coping capacity. The paper concludes that the vulnerability of indigenous communities in SIDS to environmental hazards can only be addressed through the utilisation of both indigenous and Western knowledge in a culturally compatible and sustainable manner. 相似文献
234.
导向标志可见域的实验研究 总被引:1,自引:0,他引:1
在介绍可见域概念的基础上,将导向标志可见域转化为偏移角和观察距离的关系,开展了不同偏移角下导向标志观察距离的测量实验,分别测定了两种导向标志类型(电光源型和磷光型)在两种环境照度水平(正常照明和无照明)下,9种偏移角(0°、10°、20°、30°、40°、50°、60°、70°和80°)所对应的观察距离。实验发现随着偏移角的增加,观察距离非线性的减少,导向标志的可见域为椭圆形,该椭圆的短轴是偏移角为0°时的观察距离,该项实验的开展为导向标志可见域的确定提供了基础数据。 相似文献
235.
本文简述了生化防护服的发展历史,详细介绍了防护材料的研究现状,提出了生化防护服高科技化、多功能化、智能化、高性能和舒适化的发展趋势。 相似文献
236.
基于“三调”数据分析我国东部地区XX地级市永久基本农田保护变化,从流失去向与流失空间分布两个方面深入分析了其真实境况,从而提出切实的保护政策建议。结果表明:①流失去向包括农业结构调整、建设占用和自然损毁,其中农业结构调整占用为主导。②城市圈内比圈外占用普遍严重,尤其是城乡建设占用了大量基本农田。③永久基本农田存在空间错配现象,未做到“应划尽划”。据此,提出构建农户补偿机制、县级保护任务量与存量建设指标相挂钩、协同基本农田—生态—城镇空间布局,实施圈内基本农田动态监测机制等系列措施,以提升保护效果。 相似文献
237.
Mehdi Miremadi 《Journal of the American Water Resources Association》1982,18(5):749-753
ABSTRACT: A study was conducted to evaluate the existing furrow irrigation system of Karun Agro Industry, a sugar cane plant in Daimcheh, Iran. Although the system is only eight years old, design and operational problems have reduced its efficiency by 50 percent. Lack of skilled irrigation workers, inadequate control of irrigation water, and problems with night irrigation have resulted in substantial revenue losses for the plant. This study evaluates the existing irrigation system, and recommends modifications and improvements to increase its efficiency. Final recommendations include the use of various irrigation methods, improvements to the existing system, and cancellation of night irrigation. 相似文献
238.
近10年来,咸宁市房地产业的发展以个人开发为主,城镇规模的增长明显滞后于人口的增长,出现了一系列影响房地产经济持续发展的问题。在统计分析的基础上,用线性预测法计算了本市在未来10年内房地产发展的合理速度与规模。研究结果表明:在GDP保持9%增长率的情况下,2001-2010年咸宁市每年需净增居住用房地产300万m^2,房地产业的合理增长率为12.9%。稳定和规范住宅业的发展,加强城市基础设施和社会公共服务设施建设是今后本市房地产业发展的主要取向。 相似文献
239.
"十五"期间黑龙江省自然灾害的特点及减灾对策 总被引:2,自引:2,他引:2
分析了黑龙江省"十五"期间自然灾害的发展趋势及其3种不同类型地区灾害的特点,提出减灾工作的重点是防御洪涝、干旱、低温冷害等8大灾种。根据40多年来黑龙江省减灾工作的主要经验,对每种灾害提出了切实可行的防御对策。 相似文献
240.