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1.
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   
2.
El Niño, an interannual climate event characterized by elevated oceanic temperature, is a prime threat for coral reef ecosystems worldwide, owing to their thermal threshold sensitivity. Phytoplankton plays a crucial role in the sustenance of reef trophodynamics. The cell size of the phytoplankton forms the “master morphological trait” with implications for growth, resource acquisition, and adaptability to nutrients. In the context of a strong El Niño prediction for 2015–2016, the present study was undertaken to evaluate the variations in the size-structured phytoplankton of Kavaratti reef waters, a major coral atoll along the southeast coast of India. The present study witnessed a remarkable change in the physicochemical environment of the reef water and massive coral bleaching with the progression of El Niño 2015–2016 from its peak to waning phase. The fluctuations observed in sea surface temperature, pH, and nutrient concentration of the reef water with the El Niño progression resulted in a remarkable shift in phytoplankton size structure, abundance, and community composition of the reef waters. Though low nutrient concentration of the waning phase resulted in lower phytoplankton biomass and abundance, the diazotroph Trichodesmium erythraeum predominated the reef waters, owing to its capability of the atmospheric nitrogen fixation and dissolved organic phosphate utilization.  相似文献   
3.
The fluoride (F) concentration in the coastal aquifers of Bara tract in Bharuch district, Gujarat was determined by potentiometric method using an ion-selective electrode. The fluoride concentration in these aquifers varies between 0.060 to 3.51 mg/L. It was also found that F has a positive correlation with pH and HCO(3)(-) whereas negatively correlated with Ca(2+), indicating that high fluoride in ground water is associated with low calcium content. This suggests that the higher pH of water promotes the leaching of fluoride and thus affects the concentration of fluoride in the ground water. It was also found that there exists no relationship between F, EC, and ground water table from surface in the ground water.  相似文献   
4.
In the present study we quantified the residues of organophosphorus (e.g. ethion and chlorpyrifos), organochlorine (e.g. heptachlor, dicofol, alpha-endosulfan, beta-endosulfan, endosulfan sulfate) and synthetic pyrethroid (e.g. cypermethrin and deltamethrin) pesticides in made tea, fresh tea leaves, soils and water bodies from selected tea gardens in the Dooars and Hill regions of West Bengal, India during April and November, 2006. The organophosphorus (OP) pesticide residues were detected in 100% substrate samples of made tea, fresh tea leaves and soil in the Dooars region. In the Hill region, 20% to 40% of the substrate samples contained residues of organophosphorus (OP) pesticides. The organochlorine (OC) pesticide residues were detected in 33% to 100% of the substrate samples, excluding the water bodies in the Dooars region and 0% to 40% in the Hill region. The estimated mean totals of studied pesticides were higher in fresh tea leaves than in made tea and soils. The synthetic pyrethroid (SP) pesticide residues could not be detected in the soils of both the regions and in the water bodies of the Dooars. Sixteen percent and 20% of the made tea samples exceeded the MRL level of chlorpyrifos in Dooars and Hill regions respectively. The residues of heptachlor exceeded the MRL in 33% (April) and 100% (November) in the Dooars and 40% (April) and 20% (November) in the Hill region. Based on the study it was revealed that the residues of banned items like heptachlor and chlorpyrifos in made tea may pose health hazards to the consumers.  相似文献   
5.
An info-tech complex is proposed for 286 acres (116 ha) of land within the East Calcutta wetlands. The proposed site is 15 km east of Kolkata city and only 8 km south of Dum Dum airport. The site is vacant, with pockets of agricultural land and a few degrading water-logged areas. In order to assess the likely impact of the proposed development on the environment, a rapid environmental impact assessment of an area of 10 km radius from the centre of the project site was carried out. The present status of the environment with respect to ambient air, surface water, groundwater, soil, landuse, noise, and socio-economics of the core and buffer zone has been documented and correlated with 24 project activities during construction, development and operational phases. The frequency of adverse impacts is greater than that of beneficial impacts. Out of the total adverse impacts 20 are short term, reversible and have a low magnitude. The total impact score for the proposed project is (–)468.75 and as per the Assessment Value Index Scale the environmental impact of the proposed project activities is no appreciable impact. But there are certain sectors where the environment will be adversely impacted. Therefore, appropriate measures have been suggested to ameliorate the adverse impacts. It is envisaged that if these measures are implemented then there will be an improvement in the quality of the environment, as well as life, by 687.5 units.  相似文献   
6.
The purpose of this paper is to analyse the recent behaviour of the US zinc processing industry and the impact of US government policies on it. The first section of the paper is a discussion on the basic structure and conditions of the US zinc processing industry since 1950 and how they have changed. The discussion contains a general presentation of the US zinc market, a detailed look at the behaviour of individual primary zinc processing plants in the USA, Canada, Japan and Western Europe and an analysis of US government policies and their impacts on the US zinc industry. The second section of the paper is a discussion of the factors that have contributed to the decline in US zinc processing capacity and the type of government policy that should be followed in response.  相似文献   
7.
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   
8.
Summary In Kumaun Himalaya, India, 60 percent of the rural population is dependent on natural springs for water supply. The authors claim that substantial reductions in spring water discharges are due to losses in the indigenous oak forest coverage and its partial replacement by pine. Other factors, such as overall forest cover depletion and construction activities, combine to produce severe reductions in spring discharge rates.Drs Anil Singh and Ravindra Pande are members of academic staff at Kumaun University working in the Laboratory for Hydrological and Geomorphological Investigations in the Department of Geography.  相似文献   
9.
The soluble fraction (105,000 x g, 30 min) of chicken liver homogenates contained an enzyme(s), probably a dehydrochlorinase(s), which metabolized lindane in vitro. The reaction was glutathione dependent and took place anaerobically. The enzyme(s) also metabolized the alpha- and delta-isomers but not the beta-isomer. About 66% of the in vitro metabolites were soluble in petroleum ether. From the ether-soluble fraction, o-, p- amd m-dichlorobenzene, 1,2,3- and 1,2,4-trichlorobenzene, gamma-2,3,4,5,6-pentachlorocyclohex-1-ene (gamma-PCCH), 2,3- and 2,4-dichlorophenol and 2,4,6-trichlorophenol were identified by comparison of mass spectra and gas chromatographic data with those of reference compounds. Seven additional metabolites were tentatively identified from their mass spectra data. These metabolites were: chlorobenzene, 2 isomers of trichlorocyclohexene, dichlorocyclohexadienetriol, chlorophenol, trichlorocyclohexenol and trichlorocyclohexanediol. The petroleum ether-extracted aqueous phase contained a number of unidentified conjugated metabolites. It was concluded that the metabolic pathway for lindane in the chicken is quite similar to that in the pheasant.  相似文献   
10.
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   
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