排序方式: 共有43条查询结果,搜索用时 15 毫秒
11.
Neha Badola Ashish Bahuguna Yoel Sasson Jaspal Singh Chauhan 《Frontiers of Environmental Science & Engineering》2022,16(1):7
12.
Impact of industrial air pollutants on some biochemical parameters and yield in wheat and mustard plants 总被引:1,自引:0,他引:1
The present study was carried out to determine the impacts of SO2, NO
x
, SPM and RSPM, the most common air pollutants, generated mainly due to industries and vehicles, on some biochemical parameters
and yield in wheat and mustard plants during 2006. The concentration of SO2, NO
x
, SPM and RSPM was determined at the polluted sites across the seasons, which ranged between 14.29–18.10, 20.81–22.43, 483.65–500.85
and 160.67–171.18 μg m−3, respectively. The wheat and mustard plants grown at polluted sites showed significant reduction in chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll, carotenoid, ascorbic acid, pH, relative water content and yield. The data were further analyzed using
a two way ANOVA. It is concluded that the ambient air pollutants have a potential adverse impact on biochemical parameters,
which further leads to a reduction in the yield of wheat and mustard crops. 相似文献
13.
The lacewing Chrysopa septempunctata Wesmael is an important, common predator of several insects in China, Japan, Russia, and many parts of Europe. Our field trapping experiments in northeast China showed that males of this green lacewing are strongly attracted to the lacewing pheromone of Chrysopa oculata Say, (1R,2S,5R,8R)-iridodial. The induced plant volatile, methyl salicylate, was unattractive to C. septempunctata by itself at the concentration tested, but synergistic when combined with iridodial where the lacewing population was high. (1R,4aS,7S,7aR)-Nepetalactol and (4aS,7S,7aR)-nepetalactone (aphid sex pheromone components) caught significantly more males of C. septempunctata than did blank control traps, but were inferior to iridodial dispensers, which remained strongly attractive to C. septempunctata males for at least 2.5 months. These results indicate that (1R,2S,5R,8R)-iridodial is a powerful attractant for C. septempunctata, and may have great potential for enhanced biological control of garden, agricultural, and forest insect pests. 相似文献
14.
Chauhan RS Gopinath S Razdan P Delattre C Nirmala GS Natarajan R 《Waste management (New York, N.Y.)》2008,28(11):2140-2145
Expanded polystyrene is one of the polymers produced in large quantities due to its versatile application in different fields. This polymer is one of the most intractable components in municipal solid waste. Disposal of polymeric material by pyrolysis or catalytic cracking yields valuable hydrocarbon fuels or monomers. Literature reports different types of reactors and arrangements that have uniform temperatures during pyrolysis and catalytic cracking. The present study focuses on reducing the temperature to maximize the quantity of styrene monomer in the liquid product. A bench scale reactor has been developed to recover the styrene monomer and other valuable chemicals. Experiments were carried under partial oxidation and vacuum conditions in the temperature range of 300-500 degrees C. In the pyrolysis optimization studies, the best atmospheric condition was determined to be vacuum, the pyrolysis temperature should be 500 degrees C, yield of liquid product obtained was 91.7% and yield of styrene obtained was 85.5%. In the characterization studies, distillation and IR spectroscopy experiments were carried out. The remaining of the liquid product comprises of benzene, ethyl benzene, and styrene dimers and trimers. 相似文献
15.
ABSTRACT: The non-steady drawdown distribution near a cavity well discharging from an infinite non-leaky artesian aquifer is presented. The variation of drawdown with time and distance caused by a cavity well of constant discharge in a confined aquifer of uniform thickness and uniform permeability is obtained. The solution is expressed in a series form which converges rapidly so that only two terms of the series are needed to obtain an accuracy of more than 95 percent. A simplified approach has been suggested to find the aquifer characteristics. 相似文献
16.
Chauhan SV Chaurasia B Rana A 《Journal of environmental biology / Academy of Environmental Biology, India》2004,25(3):291-297
Cassia siamea plants growing at two different sites (polluted and non-polluted) on two important roads of Agra city exhibited significant differences in their flowering phenology and floral morphology. The flowering in plants growing at polluted site is delayed and there was a marked reduction in flowering density, flowering period, size of floral parts, pollen fertility, fruit and seed-set. SEM observations revealed the presence of well developed glandular structures and reduction in the number and size of large stomata on the anther surface at polluted site. These changes were found to be closely associated with the extent of air pollution caused mainly by significant in the number of automobiles. 相似文献
17.
Energy is a vital and growing need for human activities such as transport, agriculture and industry. The transport and agriculture
sectors are major consumers of fossil fuel. However, availability of fossil fuels is limited. The use of fossil fuels is of
increasing environmental concerns because it produces toxic airborne particulates and greenhouse gases such as CO2. The increasing industrialization and motorization of the world led to a steep rise for the demand of petroleum-based fuels.
Hence, it is necessary to seek alternative fuels, which can be produced from resources available locally within the country
such as alcohol, biodiesel and vegetable oils. Biodiesel is defined as the mono alkyl esters of vegetable oils or animal fats.
Biodiesel is the best candidate for diesel fuels in the diesel engines. The advantage of biodiesel over gasoline and petroleum/diesel
is its eco-friendly nature. This article reviews the production, characterization and current status of biofuels mainly biodiesel
along with the environmental impacts of particulate matter, greenhouse gas emissions originated from biodiesel. 相似文献
18.
Salman Mohammad Chauhan Ranchan Singh Tej Prabakaran Rajendran Kim Sung Chul 《Environmental science and pollution research international》2023,30(13):36259-36275
Environmental Science and Pollution Research - The effect of the flow and geometric parameters of a dimple-roughened absorber plate on the enactment of solar air collectors (SACs) with air-impinged... 相似文献
19.
Neha Awasthi Ujjwal Kumar Q. Qureshi Anup Pradhan J. S. Chauhan Y. V. Jhala 《Regional Environmental Change》2016,16(1):31-41
Conservation practitioners require strata specific, seasonal species densities for habitat management. Herein, we use stratified distance sampling in Kanha Tiger Reserve (KTR) with 200 spatial transects and an effort of 1200 km walk in the year 2013. Analysis was done to access (a) impact of human use and (b) effect of habitat and season on ungulate densities in KTR. While a single detection function for each species was used for estimating density within human-restricted core and multiple use buffer of KTR, species-specific seasonal detections were modelled for each habitat. Ungulate biomass was 4.8 times higher in the core area compared with the buffer zone. The core supported a herbivore density and biomass of 50 ± 4.80/km2 and 26,806 ± 2573 kg/km2, respectively. Chital were found to be most abundant, having a density of 30.1 ± 4.34/km2 and contributing 33 % of the biomass with a habitat preference for grasslands (106 ± 39/km2) in summer and winter. Sambar had highest density (15.4 ± 3.34/km2) in bamboo-mixed habitat, in both seasons. Gaur contributed 39 % of the ungulate biomass and showed a seasonal shift in density from sal forests (9.65 ± 3.55/km2) in summer to miscellaneous forests (8.13 ± 1.94/km2) in winter. Barasingha were restricted to grasslands with similar summer and winter densities of 1.56 ± 0.76/km2. Chousingha were rare (0.1 ± 0.04/km2), found mostly in miscellaneous forests and plateau grasslands. Grassland and bamboo-mixed forests supported 58 % of the total ungulate biomass. Management for an optimal habitat mosaic that maintains ungulate diversity, addresses the specific needs of endangered species and maximizes ungulate biomass is recommended. 相似文献
20.
Meenu Varshney Abhijit Chandra L. K. S. Chauhan S. K. Goel 《Environmental science and pollution research international》2014,21(2):843-850
Trichloroacetic acid (TCA), a common water disinfection byproduct and a persistent metabolite of trichloroethylene (TCE), has been examined for its genotoxic potential in human lymphocytes. Chromosomal aberration (CA) and cytokinesis-block micronucleus (CBMN) assay were employed to assess the toxicity of TCA. Lymphocytes obtained from three healthy donors were exposed to 25, 50, and 100 μg/ml concentration of TCA separately. TCA exposure resulted in chromosomal anomalies and the formation of micronuclei in lymphocytes. Chromosome analysis revealed the dose-dependent and significant induction of CA. Chromatid break/chromosome break, fragments, and chromatid exchanges were commonly observed. Exposure of higher concentration (50 and 100 μg/ml) significantly inhibited mitotic index. Data obtained with CBMN assay indicated that the induction of micronucleus (MN) formation was greater than that of CA. At 25 μg/ml, TCA induced significant frequencies of MN as compared to control cells. Significant induction of MN at the lowest concentration indicates TCA may also interact with mitotic spindles. Lower percentage of CA and MN at 100 μg/ml as compared to 50 μg/ml indicates occurrence of severe cytotoxicity on exposure of 100 μg/ml TCA in lymphocytes. Collectively, results of both cytogenetic assays indicate that exposure of TCA can induce significant genotoxic and cytotoxic effects. 相似文献