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1.
Laboratory and Field Assessment of Arsenic Testing Field Kits in Bangladesh and West Bengal, India 总被引:2,自引:0,他引:2
High concentrations of arsenic in ground waters in West Bengal and Bangladeshhave become a major cause for concern in recent years. Given the enormity and the severity of the problemof arsenic poisoning, a task of evaluating the commercially available arsenic detection field kits for their capabilities was undertaken. In the light of the findings, generic specificationswere recommended which could form the basis forindigenous manufacture of these kits in the arsenic affected countries. This article presents the results of the laboratory and fieldevaluation conducted in Bangladesh and West Bengalof five arsenic testing field kits. The salient features of the kits, their merits and limitationshave been brought out. Based on the criteria of kitdesign, quality of chemicals used, colourcomparator charts, detection range, time required for analysis, cost etc., a comparative ranking ofthe kits has been made to facilitate the choice of the kit to meet specific requirements. 相似文献
2.
Karen L. Stals Matthew Wakeling Júlia Baptista Richard Caswell Andrew Parrish Julia Rankin Carolyn Tysoe Garan Jones Adam C. Gunning Hana Lango Allen Lisa Bradley Angela F. Brady Helena Carley Jenny Carmichael Bruce Castle Deirdre Cilliers Helen Cox Charu Deshpande Abhijit Dixit Jacqueline Eason Frances Elmslie Andrew E. Fry Alan Fryer Muriel Holder Tessa Homfray Emma Kivuva Victoria McKay Ruth Newbury-Ecob Michael Parker Ravi Savarirayan Claire Searle Nora Shannon Deborah Shears Sarah Smithson Ellen Thomas Peter D. Turnpenny Vinod Varghese Pradeep Vasudevan Emma Wakeling Emma L. Baple Sian Ellard 《黑龙江环境通报》2018,38(1):33-43
针对传统教与学算法在解决复杂多峰函数优化问题时,具有局部最优且搜索开发能力较差的缺点,提出了一种改进的多学习教与学优化算法,新算法为学员的每一维加入不同的教学因子,设计了基于学员均值比较的教师选择策略和向教师及学员学习的多学习策略。基于多个单峰和多峰函数的仿真结果表明,新算法跟传统的、改进的教与学算法相比,在稳定性、寻优精度和收敛速度方面更具优势。 相似文献
3.
The annual reproductive cycle of the chiton Chiton iatricus was studied for the period from September, 1977 to December, 1978. Gametogenesis is initiated in the November – December period followed by rapid gonadal growth up to March. Breeding season of C. iatricus extends up to the beginning of August. Though the emission of the gametes halts in August, the gonad never enters into the quiescent phase owing to the time required for the gametogensis. The examination of correlation between the reproductive events during the annual reproductive cycle and existing environmental factors suggests that multiple environmental factors are involved in the control of different phases of gonad growth. The collected data are discussed in the light of the reproductive physiology of C. iatricus. 相似文献
4.
The presence of suction (flow of water from channel to ground water) affects the channel hydrodynamics and increases the bed shear stress. At high bed shear stress in alluvial channels made of the non-cohesive material, sediment transport occurs as sheet flow layer of high sediment concentration. The sediment transport in the form of sheet flow has been observed in the present study when suction was applied to the non-transporting channels designed on incipient motion condition. The erosion of the channel banks contributed to the sheet flow because of the increased channel bed shear stress. An empirical relation for the thickness of sheet flow layer has been developed which includes suction as independent parameter along with others. 相似文献
5.
The present work attempts statistical analysis of groundwater quality near a Landfill site in Nagpur, India. The objective
of the present work is to figure out the impact of different factors on the quality of groundwater in the study area. Statistical
analysis of the data has been attempted by applying Factor Analysis concept. The analysis brings out the effect of five different
factors governing the groundwater quality in the study area. Based on the contribution of the different parameters present
in the extracted factors, the latter are linked to the geological setting, the leaching from the host rock, leachate of heavy
metals from the landfill as well as the bacterial contamination from landfill site and other anthropogenic activities. The
analysis brings out the vulnerability of the unconfined aquifer to contamination. 相似文献
6.
One of the important sectors that contribute to the national economy is the mining sector. During the mining of minerals and ores, waste materials in the form of overburden are generated. As these are not useful to the mine owners, they may be inappropriately disposed of into the environment, posing serious threat to the environment in the form of land degradation, water and air pollution. The present paper discusses the existing status of waste generation, its characteristics and the disposal methods being adopted in India. Impacts associated with waste disposal practices together with preventive measures for waste disposal are also discussed. Finally, strategies for improvements in existing waste management and for incorporating the same in the overall development plan for the mines are suggested. 相似文献
7.
Jayant V. Deshpande Jesse Frey Omer Ozturk 《Environmental and Ecological Statistics》2006,13(1):25-40
Ranked-set sampling from a finite population is considered in this paper. Three sampling protocols are described, and procedures
for constructing nonparametric confidence intervals for a population quantile are developed. Algorithms for computing coverage
probabilities for these confidence intervals are presented, and the use of interpolated confidence intervals is recommended
as a means to approximately achieve coverage probabilities that cannot be achieved exactly. A simulation study based on finite
populations of sizes 20, 30, 40, and 50 shows that the three sampling protocols follow a strict ordering in terms of the average
lengths of the confidence intervals they produce. This study also shows that all three ranked-set sampling protocols tend
to produce confidence intervals shorter than those produced by simple random sampling, with the difference being substantial
for two of the protocols. The interpolated confidence intervals are shown to achieve coverage probabilities quite close to
their nominal levels. Rankings done according to a highly correlated concomitant variable are shown to reduce the level of
the confidence intervals only minimally. An example to illustrate the construction of confidence intervals according to this
methodology is provided. 相似文献
8.
Environmental impact evaluation is an essential component in environmental impact assessment (EIA) study for any developmental project, wherein importance assignment to various parameters depends on human judgement/experts opinion, which involves a high order of subjectivity. In order to minimise bias and subjectivity in evaluation of impacts, and hence in decision making, three different methods, viz. Battelle environmental evaluation system (BEES), importance scale matrix (ISM), and a combination of both, are considered in the present study. A case study for a development project (setting up a new industry) in an industrial belt situated in a region, which is rich in biological resources with good agricultural productivity and having high potential for further industrial development, is presented. The results of the other two methods are compared with the widely used method of BEES. Both methods are found comparable to the BEES method. However, it is observed that the ISM approach provides a better tool for reducing bias and subjectivity occurring in human judgement. 相似文献
9.
Aditi Deshpande Sandeep Bhendigeri Tejas Shirsekar Dhanashri Dhaware R. N. Khandekar 《Environmental monitoring and assessment》2009,159(1-4):493-500
Seafood containing heavy metals as a result of environmental contamination causes toxicity in human beings. To evaluate such kind of contamination, our study targeted the analysis of metals such as lead, copper, cadmium, mercury, and arsenic in muscle tissue of the fish. The fish commonly consumed such as Brama brama (Pomfret), Rachycentron canadus (Surmai/King Fish), Rastrelliger kanagurta (Mackerel), Eleutheronema tetradactylum (Ravas/Indian salmon), and Metapenaeus monoceros (Brown Prawn) were collected from four different docks in the city. The heavy metals in tissue samples of fish were estimated using voltammeter and cold vapor atomic absorption spectrophotometer. Heavy metal concentration in the tissues varied significantly depending upon the locations from where the fish were collected. Although the concentration of arsenic, copper, cadmium, and lead were in normal range, the concentration of mercury was found to exceed the daily permissible levels (1 μg/g) as a food source for human consumption. We have analyzed heavy metals from different locations in Mumbai—Versova dock, Sassoon dock, Navi Mumbai dock, and Mazgaon dock. 相似文献
10.
Nadine Schuurman Aparna Deshpande Diana M. Allen 《Journal of the American Water Resources Association》2008,44(4):921-934
Abstract: Integrating spatial datasets from diverse sources is essential for cross‐border environmental investigations and decision‐making. This is a little investigated topic that has profound implications for the availability and reliability of spatial data. At present, ground‐water hydrostratigraphic models exist for both the Canadian or for the United States (U.S.) portion of the aquifer but few are integrated across the border. In this paper, we describe the challenges of integrating multiple source, large datasets for development of a ground‐water hydrostratigraphic model for the Abbotsford‐Sumas Aquifer. Growing concerns in Canada regarding excessive withdrawal south of the border and in the U.S. regarding nitrate contamination originating north of the border make this particular aquifer one of international interest. While much emphasis in GIScience is on theoretical solutions to data integration, such as current ontology research, this study addresses pragmatic ways of integrating data across borders. Numerous interoperability challenges including the availability of data, metadata, data formats and quality, database structure, semantics, policies, and cooperation are identified as inhibitors of data integration for cross‐border studies. The final section of the paper outlines two possible solutions for standardizing classification schemes for ground‐water models – once data heterogeneity has been addressed. 相似文献