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41.
The ground and municipal water supply samples of Karachi city were analyzed for their fluoride contents. The fluoride contents in water samples collected from the subsurface and river sources were found below the WHO recommended value for the general health of the people. However, in some industrial areas the groundwater sample showed higher level of fluoride concentration. Continuous monitoring of water resources and cautious fluoridation is suggested to maintain proper status of fluoride concentration in the drinking water.  相似文献   
42.
A pot-culture experiment was conducted in open-field conditions with highly cultivated locally transplanted (T) aman rice (Oryza sativa L.) named BR-22 in arsenic (As)-amended soil (0, 1.0, 5.0, 10.0, 20.0, 30.0, 40.0 and 50.0 mg kg−1 As) of Bangladesh to see the effect of As on the growth, yield and metal uptake of rice. Arsenic was applied to soil in the form of sodium arsenate (Na2HAsO4). Arsenic affected the plant height, tiller and panicle numbers, grain and straw yield of T-aman rice significantly (P ≤ 0.05). The grain As uptake of T-aman rice was found to increase with increase of As in soil and a high grain As uptake was observed in the treatments of 30–50 mg kg−1 As-containing soil. These levels exceed the food hygiene concentration limit of 1.0 mg kg−1 As. However, the straw As uptake varied significantly (P ≤ 0.05) from a low concentration of As in soil (5 mg kg−1) and the highest uptake was noticed in 20 mg kg−1 As treatment.  相似文献   
43.
Household solid waste management is a severe problem in big cities of developing countries. Mismanaged solid waste dumpsites produce bad sanitary, ecological and economic consequences for the whole population, especially for the poorest urban inhabitants. Dealing with this problem, this paper utilizes field data collected in the urban community of Dakar, in view of ranking nine areas of the city with respect to multiple criteria of nuisance. Nine criteria are built and organized in three families that represent three classical viewpoints: the production of wastes, their collection and their treatment. Thanks to the method PROMETHEE and the software ARGOS, we do a pair-wise comparison of the nine areas, which allows their multiple criteria rankings according to each viewpoint and then globally. Finding the worst and best areas in terms of nuisance for a better waste management in the city is our final purpose, fitting as well as possible the needs of the urban community. Based on field knowledge and on the literature, we suggest applying general and area-specific remedies to the household solid waste problems.  相似文献   
44.
Terrestrial ecosystems store more carbon (C) than the atmosphere and provide ecosystem services (ES) such as global climate regulation, by sequestering carbon within biomass and soil. Land use land cover (LULC) change is considered a key factor, playing an important role in the dynamic variations of carbon storage. The aim of this paper is to assess the effects that LULC has had on carbon stocks and consequently on climate change regulation in north-western Morocco over 21 years. To achieve this aim, the Integrated Valuation of ES and Trade-offs (InVEST) model is used to assess status and variation in the net amount of carbon stored by the different types of LULC, and the economic value of the carbon sequestered in the remaining stock. The results show that the total carbon stock increased from 4.81TgC in 1996 to 4.98TgC in 2017. Over the 21 years, the LULC changes had the greatest effect on carbon storage - an increase of 6.87% with 0.17TgC of carbon sequestered, since the majority of unused land was changed to forest and cultivated land. Based on the global costs of atmospheric carbon, we estimate the economic value of carbon storage services to be between US$1,800,000 and US$3,570,000 for the whole period, with an average yearly increment of between US$86,000 and US$170,000. The results show that the ecosystem management has had a substantial climate mitigation effect. Also, the possibility of paying for ES could inform policy on the adoption of LULC to support livelihood and management choices.  相似文献   
45.
Environmental Chemistry Letters - The removal of toxic dyes from the wastewater and industrial effluents is a major environmental challenge. Various techniques have been employed for the removal of...  相似文献   
46.
Environmental Science and Pollution Research - The purpose of this research is to measure the combing impact of corporate social responsibility on company performance and to conduct a comparative...  相似文献   
47.
Highway geometric design in mountainous areas has been a typical challenge. The combination of short horizontal curves and restricted right-of-way is a common ground for contemplating design exception in British Columbia, Canada. In practice, collision modification factors (CMFs) are advocated as quantitative measures of changes in road features on safety. However, in many situations, there are no CMFs in the literature to predict the safety impact of changing particular road features. An important example of these road features is sight distance restriction on horizontal curves. A mechanism for risk measurement has been proposed in earlier work to assist designers in comparing the safety impact of different deviations from sight distance requirements. This paper attempts to answer the questions as to whether it is possible to reduce overall risk and achieve consistency in such reduction without demanding wider right-of-way. This problem was formulated in a multi-objective optimization framework. Following this methodology, it was possible to achieve an average reduction in risk of 25% on the nine critical cross-sections. This reduction in risk was achieved without demanding wider right-of-way and without creating measurable increase in expected collision frequency due to independent re-dimensioning of different geometric elements. On theoretical grounds, this paper represents another step into the direction of developing fully probabilistic geometric design standards. On practical grounds, this paper provides an important decision mechanism that enables the efficient use of available right-of-way for new highway construction. Case studies in this paper have been applied on a major highway development in British Columba, Canada.  相似文献   
48.
Recent traffic safety research has advocated the use of the Full Bayes (FB) approach to conduct controlled before-after safety evaluations. The FB approach was shown to offer both methodological and data advantages. However, there is still a lack of complete understanding of the role that the model parameters play in the formulation of treatment effectiveness. This paper offers a novel approach to compute components related to direct and indirect treatment effects under a linear intervention model for the Safety Performance Function (SPF). The isolation of a component corresponding to the direct treatment effects enables the analyst to assess the effectiveness of the countermeasures apart from local (site-related) environmental factors. Two case studies are used to demonstrate the approach. The first case study is based on the results published from a previous safety evaluation in Iowa and the second uses a new data set from British Columbia based on the Insurance Corporation of British Columbia Road Improvement Program. The various direct and indirect components have yielded valuable insight into the effects of the model parameters on treatment impacts. Moreover, the calculation of the treatment effectiveness indices have been simplified by providing straightforward equations in terms of model parameters for the computation of their components without resorting to additional algorithms. More importantly, the results can have a significant impact on the economic evaluation of safety programs and countermeasures by allowing the calculation of collision modification factors (CMFs) that vary with time.  相似文献   
49.
Plant stature of a rice crop is an important selection criterion. As plant height is a quantitative trait it is influenced by environmental conditions. A field experiment was conducted with 40 rice genotypes to assess the fluctuation and stability of plant height in a series of 16 environmental situations. The effects of genotype (G), environment (E) and all the components of GxE interaction were highly significant. Among the genotypes, Jamai sohagi was extremely sensitive (bi = 1.37) to environmental changes, and indicating lowest adaptability over the environments. Plant height of seven genotypes viz. Basmati PNR346, Benaful, BRRIdhan28, BRRIdhan38, BRRIdhan39, Gandho kasturi and Neimat, having the bi values between 0.59 and 0.72, showed high stability against environmental changes. The otherseven genotypes viz. Badshabhog, Basmati Tapl-90, Kamini soru, Khazar, Laljira, Sarwati and Ukni madhu expressed only nonlinear sensitivity (S2di = 90-181)) and thus unpredictable fluctuation. Twenty one genotypes indicated their average stability (bi = 0.91-1.15) over the environments.  相似文献   
50.
A case of dilated coronary sinus with persistent left superior vena cava diagnosed at 33 weeks in a fetus with trisomy 18 is reported. The features of this cardiac anomaly on prenatal ultrasonography and its association with trisomy 18 are discussed. Published in 2003 John Wiley & Sons, Ltd.  相似文献   
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