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91.
92.
Javid Manzoor Mamta Rayavarapu Jaganadha Rao 《International journal of occupational safety and ergonomics》2016,22(4):473-478
Aim. The aim of the present study was to identify and evaluate predominant noise sources in the cricket bat industry of Kashmir, India. Methods. Sound levels were measured at operator’s ear level in the working zone of the workers of seven cricket bat factories. The impact assessment was made through personal interviews with each worker separately during their period of rest. Results. On average, 62.5% of the workers reported difficulty in hearing and 24.1% of the workers have become patients for hypertension. Only 58.1% of the workers complained of headache due to high noise level. Conclusions. The workers engaged in the cricket bat industry of Kashmir are exposed to high noise levels. It is suggested that personal protective equipment like ear plugs and ear muffs be used by these workers as a protection against this hazard. 相似文献
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94.
In situ flushing groundwater remediation technologies, such as cosolvent flushing, rely on the stability of the interface between the resident and displacing fluids for efficient removal of contaminants. Contrasts in density and viscosity between the resident and displacing fluids can adversely affect the stability of the displacement front. Petroleum engineers have developed techniques to describe these types of processes; however, their findings do not necessarily translate directly to aquifer remediation. The purpose of this laboratory study was to investigate how density and viscosity contrasts affected cosolvent displacements in unconfined porous media characterized by the presence of a capillary fringe. Two-dimensional flow laboratory experiments, which were partially scaled to a cosolvent flushing field experiment, were conducted to determine potential implications of flow instabilities in homogeneous sand packs. Numerical simulations were also conducted to investigate the differential impact of fluid property contrasts in unconfined and confined systems. The results from these experiments and simulations indicated that the presence of a capillary fringe was an important factor in the displacement efficiency. Buoyant forces can act to carry a lighter-than-water cosolvent preferentially into the capillary fringe during displacement of the resident groundwater. During subsequent water flooding, buoyancy forces can act to effectively trap the cosolvent in the capillary fringe, contributing to the inefficient removal of cosolvent from the aquifer. 相似文献
95.
Mohammad Mohammadi Mohammad Salehi J. N. K. Rao 《Environmental and Ecological Statistics》2014,21(2):351-371
Perez and Pontius (J Stat Comput Simul 76:755–764, 2006) introduced several bootstrap methods under adaptive cluster sampling using a Horvitz–Thompson type estimator. Using a simulation study, they showed that their proposed methods provide confidence intervals with highly understated coverage rates. In this article, we first show that their bootstrap methods provide biased bootstrap estimates. We then define two bootstrap methods, based on the method of Gross (Proceeding of the survey research methods section. American Statistical Association, Alexandria, VA, pp 181–184, 1980) and Bootstrap With Replacement, that provide unbiased bootstrap estimates of the population mean with bootstrap variances matching the corresponding unbiased variance estimator. Using a simulation study, we show that the bootstrap confidence intervals based on our proposed methods have better performance than those based on available bootstrap methods, in the sense of having coverage proportion closer to the nominal coverage level. We also compare the proposed intervals to empirical likelihood based intervals in small samples. 相似文献
96.
The aim of this study was to assess the toxic impact of copper on postlarvae (PL) of the penaeid shrimp Penaeus indicus. Tolerance, growth, oxygen consumption and metal accumulation were investigated in these PL on exposure to copper. Tolerance studies were conducted for 96 h to assess the tolerance limits of P. indicus PL exposed to different concentrations of copper using static renewal bioassay tests. Using the Probit method, the regression equation was calculated as Y=0.4899+2.3562 X, with a correlation coefficient of 0.9707. The 96 h LC50 was 0.8204 ppm. The effect of sublethal (one-fifth of 96 h LC50) copper on PL for short- and long-term exposures revealed a significant (p<0.05) decrease in the rate of oxygen consumption, metabolic rate, mean length, wet and dry weight of the exposed PL over their respective controls which can be attributed to a gradual and time-dependent accumulation of the metal, as noticed in the exposed PL through accumulation studies. Overall, the data suggest that on chronic exposure even sublethal concentrations of copper can reduce the metabolic rate and growth in P. indicus PL. This is perhaps the first attempt to use the wild P. indicus PL as a bioindicator of copper toxicity. 相似文献
97.
S. V. Raman Rao B. Padmavathi K. Sathyavelu Reddy K. Indira 《Chemistry and Ecology》2013,29(4):207-212
Exposure of a freshwater teleost, Sarotherodon mossambicus, to a sublethal concentration (26 ppm) of carbon tetrachloride for periods up to 30 days led to significant changes in the soluble protein fractions (albumin and globulins) and free amino acid content. the decrease in total protein content was greater in liver than in muscle. the protein loss was expected due to the impairement of protein synthetic activity during stress conditions. 相似文献
98.
An attempt to depict the wastewater treatment system for the production of ammonium perchlorate, a component of solid propellant used in space vehicles, has been made. The waste‐water management system uses solar ponds and seawater dilution for the retention and disposal of the undesirable constituents of the wastewater. The details of the wastewater generation and its treatment are highlighted in this paper. 相似文献
99.
SUMMARY An approach to the rehabilitation of degraded community lands built on people's perceptions and traditional knowledge was developed, implemented on a small scale (6 ha plot), and evaluated in terms of economic and ecological costs and benefits over a period of 5 years in a mid-altitude (1200 m) village of Garhwal Himalaya. Rehabilitation comprised establishment of water harvesting tanks, organic management of soil, agroforestry (native multipurpose trees t traditional crops), and decision making by the whole village community. Costs and benefits under irrigated and unirrigated conditions were compared. The total cost of establishing the irrigated agroforestry system was 1.23 fold that of the unirrigated one, whereas the total benefit was 2.09 fold. The average standing above-ground biomass of the 4-year-old plantation in the irrigated agroforestry system was 11.69 t/ha compared to 8.34 t/ha in the unirrigated system. Improvement in soil properties was more pronounced in the irrigated system than in the unirrigated one. Nutrient input, an input derived largely from forest biomass, in the unirrigated system was nearly 3 times higher than that in the irrigated system. It is concluded that, considering the local and national/regional/global interests in an integrated manner, agroforestry incorporating water management would be a more effective option for rehabilitating degraded community lands than the afforestation currently being attempted by the government in the mid-altitudes of Indian Himalaya. 相似文献
100.