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1.
The objective of the study is to investigate spatio-temporal variations of PM10, PM2.5, and PM1 concentrations at seven residential sites, located in the vicinity of opencast coal projects, Basundhara Garjanbahal Area (BGA), India. Meteorological parameters such as wind speed, wind direction, relative humidity, and temperature were collected simultaneously with PM concentrations. Mean concentrations of PM10 in the range 215 ± 169–526 ± 412 μg m?3, PM2.5 in the range of 91 ± 79–297 ± 107 μg m?3, PM1 in the range of 68 ± 60–247 ± 84 μg m?3 were obtained. Coarse fractions (PM2.5–10) varied from 27 to 58% whereas fine fractions (PM1–2.5 and PM1) varied in the range of 51–73%. PM2.5 concentration was 41–74% of PM10 concentration, PM1 concentration was 31–62% of PM10 concentration, and PM1 concentration was 73–83% of PM2.5 concentration. Role of meteorology on PM concentrations was assessed using correlation analysis. Linear relationships were established among PM concentrations using least square regression analysis. With the aid of principal component analysis, two components were drawn out of eight variables, which represent more than 75% of variance. The results indicated that major sources of air pollutants (PM10, PM2.5, PM1, CO, CO2) at the residential sites are road dust raised by vehicular movement, spillage of coal generated during transportation, spontaneous combustion of coal, and biomass burning in village area.  相似文献   
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Mahmood  Shakeel  Rani  Razia 《Natural Hazards》2022,111(3):3053-3069
Natural Hazards - This study is an effort of people-centric geo-spatial exposure and damage assessment of 2014-flood in Upper Indus Plain (UIP). Community-based disaster risk management (CBDRM)...  相似文献   
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Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish Heteropneustes fossilis. Larvae were exposed to two concentrations (150 and 250 μg/L) of sumithion with one control in three replicates of each. Larvae samples were collected at 20- and 24-h intervals followed by observation under a digital microscope. Exposures of stinging catfish larvae to sumithion produced deformities including irregular head shape, lordosis, yolk sac edema, body arcuation, tissue ulceration, etc. The mortality rates of larvae were significantly increased in response to increase in sumithion concentrations. Furthermore, around 30% of the total adult stinging catfish reared in sumithiontreated aquaculture ponds were found to be deformed permanently. These findings highlight that exposure of stinging catfish to sumithion at the critical and sensitive stages in their life cycle may significantly reduce the number of returning adults. Therefore, the use of sumithion for crop protection needs to be considered carefully and alternatives to sumithion should to be developed for controlling aquatic insects in aqua-ponds during larval rearing.  相似文献   
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In the present study, analysis of 238U concentration in 40 drinking water samples collected from different locations of Jodhpur, Nagaur, Bikaner and Jhunjhunu districts of Rajasthan, India has been carried out by using high resolution inductively coupled plasma mass spectroscopy (HR-ICP-MS) technique. The water samples were taken from hand pumps and tube wells having depths ranging from 50 to 800 feet. The measured uranium concentration lies in the range from 0.89 to 166.89 μg l-1 with the mean value of 31.72 μg l-1. The measured uranium content in twelve water samples was found to be higher than the safe limit of 30 μg l-1 as recommended by World Health Organization (WHO, 2011) and US Environmental Protection Agency (USEPA, 2011). Radiological risk calculated in the form of annual effective dose estimated from annual uranium intake ranges from 0.66 to 138.63 μSv y-1 with the mean value of 26.28 μSv y-1. The annual effective dose in two drinking water samples was found to be greater than WHO (2004) recommended level of 100 μSv y-1. Chemical risk calculated in the form of lifetime average daily dose (LAAD) estimated from the water samples varies from 0.02 to 4.57 μg kg-1 d-1 with the mean value of 0.87 μg kg-1 d-1. The lifetime average daily dose (LAAD) of ten drinking water samples was found to be greater than WHO (2011) recommended level of 1 μg kg-1 d-1. The corresponding values of hazard quotient of 48% water samples were found to be greater than unity.A good positive correlation of uranium concentration with total dissolved solids (TDS) and conductance has been observed. However no correlation of uranium concentration with pH was observed. The results revels that uranium concentration in drinking water samples of the study area can cause radiological and chemical threat to the inhabitants.  相似文献   
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In Shear strength reduction (SSR) technique, the factor of safety (FOS) is defined as the ratio of the material’s actual shear strength to the minimum shear strength required to prevent failure. Failure surface is found automatically through the zones within the material, where applied shear stresses cross the shear strength of the material. In this paper, a review of the technique is discussed in reference to FLAC. A brief background of the approach together with detailed procedure is presented.An attempt is made to exhibit the shear strength dependency of the strain. As stability of the slope is a function of the shear strength, the development of failure strain reflects the potential failure zone of slope. The shear strain developed in the slope increases with reduction in the shear strength and is reflected in the analysis. The concept of failure ratio (Rf) is incorporated in shear strength reduction technique and is demonstrated. Relationships between the critical shear strength reduction ratio and the safety factor are examined.  相似文献   
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The basement gneiss of the Shillong plateau and the overlying rocks of the Shillong basin have been dissected by a number of mafic dyke swarms represented by older Proterozoic dolerite dykes and sills named as Khasi greenstone and the younger set of Cretaceous dykes. The older dolerites dykes of Shillong basin are partly metamorphosed and have undergone low-grade metamorphism compared to the fresh unmetamorphosed Cretaceous dykes dominantly exposed in the BGC of West Garo hills region. The Khasi greenstones are tholeiitic in composition and range from basalt to basaltic andesite. Most of the metamorphosed mafic dykes indicate continental nature with some amount of overlapping oceanic tectonic setting. Palaeomagnetic study of the metadolerite dykes show a direction of magnetization of Dm=29, Im=38 (α95 = 28.84; k = 48.33; N = 2) with a palaeolatitude of 21.3° N to the Indian sub-continent that clearly support the Proterozoic dyke/dyke swarm emplacement in the region. The magnetic carrier as inferred from IRM studies is magnetite in the range of psuedosingle to multi domain (MD) states with minor contribution from hematite.  相似文献   
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The Narippara area, which is nestled in the Banasuramala of Wayanad district, witnessed initiation of landslide, which was manifested in the form of curvilinear cracks running for a length of 170 m. In the event of continuous rainfall, these cracks may get reactivated, leading to a major landslide. This could affect the life and livelihood of a large number of families living downslope and could cause extensive damage to property. Extensive mining for building stones in this area has been a cause for much concern amongst the local population. This study aims at understanding the impact of quarrying on slope stability through geotechnical, geophysical and environmental impact assessment (EIA). Geotechnical analysis shows that the area is stable under dry condition but parts of the area are critical under wet and saturated conditions. Moreover, resistivity studies revealed that the cracks that had developed extend up to the bedrock and the suspected mechanism of failure will be translational in nature. EIA reveal that due to quarrying and mining operations, the possibility of land disturbances cannot be ruled out during the monsoon season. In the present study, an attempt is also made to suggest management strategies for mitigating further effects of landslides in this area.  相似文献   
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