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481.
Surinder Singh Rohit Mehra Kulwant Singh 《Atmospheric environment (Oxford, England : 1994)》2005,39(40):7761-7767
Indoor radon measurements in 105 dwellings belonging to 21 villages of Muktsar and Ferozepur districts of Malwa region, Punjab, have been carried out, using LR-115 type II cellulose nitrate films in the bare mode. The annual average indoor radon value in the study area varies from 76.25 to 145.50 Bq m−3, which is well within the recommended action level [ICRP, 1993. Protection against radon at home and work. Annals of ICRP, ICRP Publication, p. 65]. Seasonal variation of indoor radon shows high values in winter and low values in summer. The winter/summer ratio of radon concentration has been computed for all 105 dwellings. The winter/summer ratio of indoor radon ranges from 0.84 to 1.89 with an average of 1.46. The indoor radon values obtained in the present investigation are more than the world average of 40 Bq m−3 相似文献
482.
Mitigation of methane (CH4) and nitrous oxide (N2O) emissions from soil is important to reduce the global warming. Efficacy of five nitrification inhibitors, i.e. neem (Azadirachta melia) cake, thiosulphate, coated calcium carbide, neem oil coated urea and dicyandiamide (DCD) and one urease inhibitor, hydroquinone, in mitigating N2O and CH4 emissions from fertilized soil was tested in rice-wheat system in the Indo-Gangetic plains. The closed chamber technique was used for the collection of gas samples, which were analyzed using gas chromatography. Reduction in N2O emission on the application of nitrification/urease inhibitors along with urea ranged from 5% with hydroquinone to 31% with thiosulphate in rice and 7% with hydroquinone to 29% with DCD in wheat crop. The inhibitors also influenced the emission of CH4. While application of neem coated urea, coated calcium carbide, neem oil and DCD reduced the emission of CH4; hydroquinone and thiosulphate increased the emission when compared to urea alone. However, the global warming potential was lower with the inhibitors (except hydroquinone) as compared to urea alone, suggesting that these substances could be used for mitigating greenhouse gas emission from the rice-wheat systems. 相似文献
483.
Pathak H Bhatia A Prasad S Singh S Kumar S Jain MC Kumar U 《Environmental monitoring and assessment》2002,77(2):163-178
Nitrous oxide (N2O) accounts for 5%of the total enhanced greenhouse effect and responsiblefor the destruction of the stratospheric ozone. The rice-wheat cropping system occupying 26 million ha ofproductive land in Asia could be a major source ofN2O as most of the fertilizer N in this region isconsumed by this system. Emission of N2O asinfluenced by application of urea, urea plus farm yardmanure (FYM), and urea plus dicyandiamide (DCD), anitrification inhibitor, was studied in rice-wheatsystems of Indo-Gangetic plains of India. Total emissionof N2O-N from the rice-wheat systems varied between654 g ha-1 in unfertilized plots and 1570 g ha-1 in urea fertilized plots. Application of FYM and DCDreduced emission of N2O-N in rice. The magnitude ofreduction was higher with DCD. In wheat also N2O-Nemission was reduced by DCD. FYM applied in rice had noresidual effect on N2O-N emission in wheat. In riceintermittent wetting and drying condition of soilresulted in higher N2O-N emission than that ofsaturated soil condition. Treatments with 5 irrigationsgave higher emissions in wheat than those with 3irrigations. In rice-wheat system, typical of a farmer'sfield in Indo-Gangetic plains, where 240 kg N isgenerally applied through urea, N2O-N emission is1570 g ha-1 (0.38% of applied N) and application ofFYM and DCD reduced it to 1415 and 1096 g ha-1,respectively. 相似文献
484.
485.
A study of temporal variation in methane efflux from the rice-fields indicated that weeds could modulate the CH4 emission by transporting atmospheric O2 more efficiently than rice plants to the rhizosphere, which suppressed CH4 formation in the oxic condition, inhibiting methanogenic activity. A more oxic environment in the sediment was reflected by the higher redox potential in the weed growing plots. Besides, cultivar differences in methane efflux might be attributed to various plant activities, more importantly root exudation, development of aerenchyma and the biomass. Peak emission of CH4 at the flowering stage in all the rice cultivars was associated with maximum extension of root mat, releasing exudates, which serve as carbon source for the methanogenic bacteria for CH4 formation. 相似文献
486.
Fission track technique has been used for uranium estimation in drinking water samples collected from some areas of Amritsar District, Punjab, India. The uranium concentration in water samples is found to vary from 3.19 to 45.59 microg l(-1). Some of the physico-chemical properties such as pH, conductance and hardness and the content of calcium, magnesium, total dissolved solids (TDS), sodium, potassium, chloride, nitrate and heavy metals viz. zinc, cadmium, lead and copper have been determined in water samples. An attempt has been made to correlate uranium concentration with these water quality parameters. A positive correlation of conductance, nitrate, chloride, sodium, potassium, magnesium, TDS, calcium and hardness with uranium concentration has been observed. However, no correlation has been observed between the concentration of uranium and the heavy metals analysed. 相似文献
487.
Srivastava Tapendra Kumar Singh Pushpa Verma Ram Ratan 《Environment, Development and Sustainability》2022,24(3):3588-3618
Environment, Development and Sustainability - Weather variability over the long run exhibits the trends of change in climate and forewarns for development and deployment of adaptation measures.... 相似文献
488.
The arsenic tolerant bacterial strains Staphylococcus arlettae(NBRIEAG-6), Staphylococcus sp.(NBRIEAG-8) and Brevibacillus sp.(NBRIEAG-9) were tested for their roles in enhancing plant growth and induction of stress-related enzymes in rice(Oryza sativa L. cv. NDR-359) plants at two different concentrations, 30 and 15 mg/kg of As(V) and As(III), respectively. An experiment was conducted to test the effect of these strains on plant growth promotion and arsenic uptake. We found 30%–40% reduction in total As uptake in bacteria-inoculated plants, with increased plant growth parameters compared to non-inoculated plants. Moreover, the bacteria-inoculated plants showed reduced activity of total glutathione(GSH) and glutathione reductase(GR) compared to their respective controls, which suggests the bacteria-mediated reduction of oxidative stress in plants. Thus, these strains were found to be beneficial in terms of the biochemical and physiological status of the plants under arsenic stress conditions.Furthermore, one-way ANOVA and principal component analysis(PCA) on enzymatic and non-enzymatic assays also revealed clear variations. The results support the distinction between control and treatments in both shoots and roots. Therefore, this study demonstrates the potential of rhizobacteria in alleviating arsenic stress in rice plants. 相似文献
489.
J. McInnis S. Singh I. Huq 《Mitigation and Adaptation Strategies for Global Change》2016,21(4):479-486
Coal is the most abundant hydrocarbon energy source in the world. It also produces a very high volume of greenhouse gases using the current production technology. It is more difficult to handle and transport than crude oil and natural gas. We face a challenge: how can we access this abundant resource and at the same time mitigate global environmental challenges, in particular, the production of carbon dioxide (CO2)? The editors of this special edition journal consider the opportunity to increase the utilization of this globally abundant resource and recover it in an environmentally sustainable manner. Underground coal gasification (UCG) is the recovery of energy from coal by gasifying the coal underground. This process produces a high calorific synthesis gas, which can be applied for electricity generation and/or the production of fuels and chemicals. The carbon dioxide emissions are relatively pure and the surface facilities are limited in their environmental footprint. Unused carbon is readily separated and can be geo-sequester in the resulting cavity. The cavity is also being considered as a potential option to mitigate against change impacts of other sources of carbon dioxide (CO2) emissions. These outcomes mean there is an opportunity to provide developing and developed countries a source of low-cost clean energy. Further, the burning of coal in situ means that the traditional dangers of underground mining and extraction are reduced, a higher percentage of the coal is actually recovered and the resulting cavern creates the potential for a long-term storage solution of the gasification wastes. The process is not without challenges. Ground subsidence and groundwater pollution are two potential environmental impacts that need to be averted for this process to be acceptable. It is essential to advance the understanding of this practice and this special edition journal seeks to share the progress that scientists are making in this dynamic field. The technical challenges are being addressed by researchers around the world who work to resolve and understand how burning coal underground impacts the geology, the surface land, and ground water both in the short and the long term. This special issue reviews the process of UCG and considers the opportunities, challenges, risks, competitive analysis and synergies, commercial initiatives and a roadmap to solutions via the modelling and simulation of UCG. Building and then disseminating the fundamental knowledge of UCG will enhance policy development, best practices and processes that reflect the global desires for energy production with reduced environmental impact. 相似文献