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排序方式: 共有594条查询结果,搜索用时 31 毫秒
491.
Residues dynamics of Endosulfan (525.00 g a.i. ha(-1)), Imidacloprid seed treatment (21 g a.i. kg(-1)), Lambdacyhalothrin (75.00 g a.i. ha(-1)) and Spiromesifen (225.00 g a.i. ha(-1)) in nectar and pollen of mustard, Brassica juncea (L.) Czern. grown in Himachal Pradesh (India) were determined through bioassay (using Drosophila melanogaster Meig. as test organism) and GC (Gas chromatographic) and HPLC (High performance liquid chromatographic) methods. In general chromatographic methods were more sensitive for the determination of above given pesticides compared to bioassay method. Average recoveries in nectar samples varied between 82.85 and 88.90% by bioassay and 91.20 and 93.55% by chromatographic techniques. In pollen samples, recoveries varied between 81.44 and 86.44% by bioassay and 88.50 and 91.30% by chromatographic methods. Imidacloprid residues were neither found in nectar nor in pollen samples at the time of sampling i.e. 50% of flowering. The order of average half life of residues was: Lambdacyhalothrin (12.45 h) < Spiromesifen (19.99 h) < Endosulfan (27.49 h) for nectar and Spiromesifen (9.69 h) < Lambdacyhalothrin (12.44 h) < Endosulfan (17.84 h) for pollen samples. It was found that Imidcloprid seed treatment was practically harmless to honey bees, whereas a waiting period of 5 days must be observed on crops sprayed with these chemicals during blooms to avoid any accidental hazards to honey bees. 相似文献
492.
Road sides provide suitable conditions for the establishment and growth of non-native species. The phenomenon of non-native species spread through roads has further increased due to rapid anthropogenic developments. Here we intend to investigate the status of native and non-native species and how the species richness and diversity change in a perpendicular road transect across the three different road use types in the central highlands of India. Presence of 55 non-native species was recorded, of the total 71 species along the road sides. Non-native species richness significantly increased with increasing road use type. Although, the species diversity significantly decreased from road verges to the forest interior in all the road use types. Indicating the role of non-native propagule spread through the roads into the interior forest landscapes. The study gives a management implication, to restrict the non-native species spread from the road sides to the forest interior, irrespective of road use types. 相似文献
493.
Indu Chopra Beena Kumari S. K. Sharma 《Environmental monitoring and assessment》2010,160(1-4):123-126
The mobility of pendimethalin in sandy loam soil was studied in soil columns under laboratory conditions at two application rates, 1.0 and 2.0 kg a.i. ha???1, with simulated rainfall of 300 mm. The maximum concentration of the herbicide was found in the top 10 cm layer, though it was found distributed in soil at all the depths at both the doses. 相似文献
494.
Chandra N Sharma P Pashkov GL Voskresenskaya EN Amritphale SS Baghel NS 《Waste management (New York, N.Y.)》2008,28(10):1993-2002
We present here a study of the sintering of fly ash and its mixture with low alkali pyrophyllite in the presence of sodium hexa meta phosphate (SHMP), a complex activator of sintering, for the purpose of wall tile manufacturing. The sintering of fly ash with SHMP in the temperature range 925-1050 degrees C produces tiles with low impact strength; however, the incremental addition of low alkali pyrophyllite improves impact strength. The impact strength of composites with 40% (w/w) pyrophyllite in the fly ash-pyrophyllite mix satisfies the acceptable limit (19.6J/m) set by the Indian Standards Institute for wall tiles. Increasing the pyrophyllite content results in an increase in the apparent density of tiles, while shrinkage and water absorption decrease. The strength of fly ash tiles is attributed to the formation of a silicophosphate phase; in pyrophyllite rich tiles, it is attributed to the formation of a tridymite-structured T-AlPO(4) phase. Scanning electron micrographs show that the reinforcing rod shaped T-AlPO(4) crystals become more prominent as the pyrophyllite content increases in the sintered tiles. 相似文献
495.
Moti L. Mittal Chhemendra Sharma Richa Singh 《Environmental monitoring and assessment》2014,186(10):6857-6866
This study aims to estimate the emissions of carbon dioxide (CO2), sulfur dioxide (SO2), and nitric oxide (NO) for coal combustion in thermal power plants in India using plant-specific emission factors during the period of 2001/02 to 2009/10. The mass emission factors have been theoretically calculated using the basic principles of combustion under representative prevailing operating conditions in the plants and fuel composition. The results show that from 2001/02 to 2009/10 period, total CO2 emissions have increased from 324 to 499 Mt/year; SO2 emissions have increased from 2,519 to 3,840 kt/year; and NO emissions have increased from 948 to 1,539 kt/year from the Indian coal-fired power plants. National average emissions per unit of electricity from the power plants do not show a noticeable improvement during this period. Emission efficiencies for new plants that use improved technology are found to be better than those of old plants. As per these estimates, the national average of CO2 emissions per unit of electricity varies between 0.91 and 0.95 kg/kWh while SO2 and NO emissions vary in the range of 6.9 to 7.3 and 2.8 to 2.9 g/kWh, respectively. Yamunagar plant in Haryana state showed the highest emission efficiencies with CO2 emissions as 0.58 kg/kWh, SO2 emissions as 3.87 g/kWh, and NO emissions as 1.78 g/kWh, while the Faridabad plant has the lowest emission efficiencies with CO2 emissions as 1.5 kg/kWh, SO2 emissions as 10.56 g/kWh, and NO emissions as 4.85 g/kWh. Emission values at other plants vary between the values of these two plants. 相似文献
496.
T. S. Panwar Rakesh K. Hooda H. Lihavainen A. P. Hyvarinen V. P Sharma Y. Viisanen 《Environmental monitoring and assessment》2013,185(6):4753-4764
Continuous aerosol measurements were made at a regional background station (Mukteshwar) located in a rural Himalayan mountain terrain from December 2005 to December 2008 for a period of 3 years. The average concentrations of particulate matter less than or equal to 10 μm (PM10), particulate matter less than or equal to 2.5 μm (PM2.5) and black carbon (BC) are 46.0, 26.6 and 0.85 μg/m3 during the study period. Majority of the PM10 values lie below 100 μg/m3 while majority of the PM2.5 values lie below 30 μg/m3. It is further seen that during the monsoon months, especially July and August, the average values are comparatively low. It is also noted that the PM2.5/PM10 ratios between 0.50 and 0.75 have the maximum frequency distribution in the data set. Furthermore, the monthly mean ratio of BC to PM2.5 mass lies between 3.0 and 7.5 % during the study period. Though the average PM10 and PM2.5 concentrations during the study period are less than the respective Indian ambient air quality standards, however, they are still above the WHO guidelines and would have adverse health impacts. This shows that even in rural/background regions that are far away from major pollution sources or urban areas, the aerosol concentrations are significant and require long-term monitoring, source quantification and aerosol model simulations. 相似文献
497.
498.
Vinay Sharma J. S. Banait R. C. Larock P. P. Kundu 《Journal of Polymers and the Environment》2010,18(3):235-242
Linseed oil-based polymers have been synthesized via cationic and thermal polymerization and characterized through various
techniques, such as SEM, DMA, DSC and TGA. The morphology of the polymer samples after extraction reveals the smooth structure
of the polymer matrix. With an increase in oil content, the morphology is observed to be more loosely bound. With an increase
in linseed oil content in the samples, the room temperature storage modulus (E′) varies from 10.4 × 107 to 1.8 × 107 Pa. The glass transition temperatures measured through DMA of the cationic samples ranges from 70 to −6 °C and the crosslink
densities range from 18.4 × 103 to 3.4 × 103 mol/m3. The glass transition temperatures of the thermal samples range from 106 to −4 °C and the crosslink densities range from
7.7 × 103 to 2.4 × 103 mol/m3. The TGA results show three stages of degradation of the polymer samples and it is also revealed that these polymers are
stable up to 200 °C, showing negligible decomposition. 相似文献
499.
Purpose
Biodesulfurization (BDS) has the potential to desulfurize dibenzothiophene (DBT) and its alkylated derivatives, the compounds that are otherwise refractory to hydrodesulfurization (HDS). Thermophilic microorganisms are more appropriate to be used for BDS applications following HDS. The aim of the present study was to isolate a thermophilic microorganism and to explore its commercial relevance for BDS process.Methods
The desulfurizing thermophilic strain was isolated and enriched from various soil and water samples using sulfur free medium (SFM) supplemented with DBT. Microbiological and genomic approach was used to characterize the strain. Desulfurization reactions were carried out using DBT and petroleum oils at 45°C followed by different analytical procedures.Results
We report the isolation of a thermophilic bacterium Klebsiella sp. 13T from contaminated soils collected from petroleum refinery. HPLC analysis revealed that Klebsiella sp. 13T could desulfurize DBT to 2-hydroxybiphenyl (2-HBP) at 45°C through 4S pathway. In addition, adapted cells of Klebsiella sp. 13T were found to remove 22?C53% of sulfur from different petroleum oils with highest sulfur removal from light crude oil.Conclusion
Klebsiella sp. 13T is a potential candidate for BDS because of its thermophilic nature and capability to desulfurize petroleum oils. 相似文献500.
K. Michael A. Golab V. Shulakova J. Ennis-King G. Allinson S. Sharma T. Aiken 《International Journal of Greenhouse Gas Control》2010,4(4):659-667
The experience from CO2 injection at pilot projects (Frio, Ketzin, Nagaoka, US Regional Partnerships) and existing commercial operations (Sleipner, Snøhvit, In Salah, acid-gas injection) demonstrates that CO2 geological storage in saline aquifers is technologically feasible. Monitoring and verification technologies have been tested and demonstrated to detect and track the CO2 plume in different subsurface geological environments. By the end of 2008, approximately 20 Mt of CO2 had been successfully injected into saline aquifers by existing operations. Currently, the highest injection rate and total storage volume for a single storage operation are approximately 1 Mt CO2/year and 25 Mt, respectively. If carbon capture and storage (CCS) is to be an effective option for decreasing greenhouse gas emissions, commercial-scale storage operations will require orders of magnitude larger storage capacity than accessed by the existing sites. As a result, new demonstration projects will need to develop and test injection strategies that consider multiple injection wells and the optimisation of the usage of storage space. To accelerate large-scale CCS deployment, demonstration projects should be selected that can be readily employed for commercial use; i.e. projects that fully integrate the capture, transport and storage processes at an industrial emissions source. 相似文献