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191.
The presence of engineered nanoparticles is continuously increasing in our environment and causing potential risks to the ecosystem. Researchers from various fields report many articles on the effects of different nanoparticles on plants, animals and microorganisms. Here we have studied for the first time the effect of nano mullite (NMu) and their metal- amended derivatives on the growth of mung bean plants. Results shows that the metal- amended NMu exerts adverse effects on the growth and biomass production of plants compared to NMu. For toxicity studies, we measured the germination index and relative root elongation, while leakage of electrolytes and root oxidizability were measured to study the effect of NMu on mung bean seeds and seedling tissues. Translocation and accumulation of NMu within different parts of the plant body were proved by elemental analysis of dried plant samples. 相似文献
192.
We apply a fixed-effects model to examine the impact of trade and environmental policies on air quality at ports along the U.S.-Mexico border. We control for other factors influencing air quality, such as air quality of cities near the border, volume of traffic flows and congestion. Results show the air quality improved after 2004, when the diesel engine policy was applied. We see mixed results for the trade policy, whose implementation time varies across ports along the international border. Controlling for air quality in cities near the border is essential for assessing the policy contributions to air quality. 相似文献
193.
Developing countries across the world have embraced the policy of high economic growth as a means to reduce poverty. This economic growth largely based on industrial output is fast degrading the ecosystems, jeopardizing their long term sustainability. Environmental Impact Assessment (EIA) has long been recognized as a tool which can help in protecting the ecosystems and aid sustainable development. The Screening guidelines for EIA reflect the level of commitment the nation displays towards tightening its environmental protection system. The paper analyses the screening process for EIA in India and dissects the rationale behind the exclusions and thresholds set in the screening process. The screening process in India is compared with that of the European Union with the aim of understanding the extent of deviations from a screening approach in the context of better economic development. It is found that the Indian system excludes many activities from the purview of screening itself when compared to the EU. The constraints responsible for these exclusions are discussed and the shortcomings of the current command and control system of environmental management in India are also explained. It is suggested that an ecosystem carrying capacity based management system can provide significant inputs to enhance the effectiveness of EIA process from screening to monitoring. 相似文献
194.
Baigabelov Adilbek Das Avimanyu Young Courtney 《Journal of Material Cycles and Waste Management》2021,23(6):2162-2178
Journal of Material Cycles and Waste Management - Froth flotation and elutriation were found to be effective in separating individual plastics from a plastic mixture by exploiting differential... 相似文献
195.
Studies on pigments,proteins and photosynthetic rates in some mangroves and mangrove associates from Bhitarkanika,Orissa 总被引:6,自引:0,他引:6
Pigment contents, proteins and net photosynthesis were investigated in fully developed leaf of 1-year-old seedlings of six mangroves (Bruguiera gymnorrhiza, Rhizophora apiculata) and mangrove associates (Caesalpinia bonduc, Cerbera manghas, Derris heterophylla, Thespesia populnea), collected from Bhitarkanika, located on the east coast of India. Large variations in the photosynthetic rates (PN) among the six species were observed, ranging from 10.16 µmol CO2 m-2 s-1 in C. bonduc to 15.28 µmol CO2 m-2 s-1 in R. apiculata. The total leaf protein content ranged from 12.09 mg g-1 dry wt in T. populnea to 51.89 mg g-1 dry wt in B. gymnorrhiza. The chlorophyll a/b ratio was typically about 3.0 in all the studied species, except C. bonduc (2.8). Photosynthetic rates and chl a/b ratio in the leaves were found to be correlated. Analysis of chlorophyll and xanthophyll spectra suggested: (1) variations in different forms and amounts of carotenes as well as xanthophylls and (2) the presence of high amounts of near-UV-absorbing substances in leaves, particularly in the two mangroves (B. gymnorrhiza, R. apiculata) and a mangrove associate (T. populnea), which appears to be an adaptive feature. Estimation of the chl a/b ratios in isolated thylakoids yielded a low value of 1.8 for R. apiculata and >2.6 for other species. The total protein/chlorophyll ratios in thylakoids varied considerably from 3.14 (D. heterophylla) to 10.88 (T. populnea) among the mangrove associates and from 16.09 to 18.88 between the members of the Rhizophoraceae. The chlorophyll/carotenoid ratios in thylakoids of the six species were more or less similar. The absorption spectra for washed thylakoids of C. manghas and D. heterophylla exhibited absorption characteristics typical for C3-plant thylakoids. However, thylakoids isolated from R. apiculata, B. gymnorrhiza, C. bonduc and T. populnea exhibited an unusual increase in absorption in the blue region (380-410 nm) of the absorption spectrum. The presence of high-absorbing (in the short-wavelength, near-UV region) pigments appears to be closely associated with the thylakoids in R. apiculata and T. populnea. Our results, therefore, suggest a wide range of variation, not only in protein and pigment contents of photosynthetic tissues, but also in the spectral characteristics and composition of the pigments in mangrove species. An understanding of the nature of these pigments in mangroves and their associates, under their natural conditions and especially in relation to eco-physiological adaptations, is necessary, not only in relation to conservation, but also to allow propagation under different salinity conditions. 相似文献
196.
T.S. Ramulu S.K. Sahoo R.K. Mohapatra G. Roy Chaudhury S.N. Das 《Atmospheric environment (Oxford, England : 1994)》2009,43(12):2087-2090
The Seasonally Integrated Flux (SIF) of N2O emission during pulse cultivation in Rabi season (Season-I: December to April) in rain-fed uplands of Orissa, was found to be 17.7 ± 0.07, 18.7 ± 0.16 and 43.3 ± 0.14 gha?1 for horse gram (HG), black gram (BG) and green gram (GG) respectively. During the subsequent Rabi season (Season-II), the SIF of N2O for BG and GG cultivated in the same fields were 20.9 ± 0.24 and 38.0 ± 0.42 gha?1 respectively. Similarly SIF values during rice cultivation with different cultivars have also been calculated to be in the range ?20.05 ± 0.33 to 21.98 ± 0.29. Statistical analysis showed good correlation of N2O emission with climatic and soil parameters like temperature, nutrient N and organic matter in soil during pulse cultivation. Multivariate analysis was carried out to factorize the results obtained. Using student ‘t’ test, the N2O emission was observed to be similar for two consecutive Rabi seasons for pulses like BG and GG. 相似文献
197.
198.
Two industrial solid waste products generated by Indian coal-fired power plants, namely pond ash and fly ash, were used in combination with local clay to develop building bricks. The clay were mixed with the two different ashes in the range 10 to 90 wt.%, hydraulically pressed and fired at 1000 degrees C. The fired products were characterized for various quality properties required for building bricks. The properties of the optimal compositions were compared with conventional red clay bricks including the developed microstructures and the comparative study generally showed that te ash-clay bricks were of superior quality to the conventional products. 相似文献
199.
A field experiment has been conducted with four systemic herbicides viz., butachlor [N-(butoxymethyl)-2-chloro-2',6'-diethyl-acetanilide], fluchloralin [N-(2-chloroethyl)-(2,6-dinitro-N-propyl-4-trifluoromethyl) aniline], oxadiazon [5-terbutyl-3-(2,4-dichloro-5-isopro poxyphenyl)-1,3,4-oxadiazol-2-one] and oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenyl)-4-(trifluoromethyl) benzene] at their recommended field rates (2.0, 1.5, 0.4 and 0.12kga.i.ha(-1), respectively) to investigate their effects on growth and activities of aerobic non-symbiotic N(2)-fixing bacteria and phosphate solubilizing microorganisms in relation to availability of nitrogen and phosphorus in the rhizosphere soils as well as yield of the rice crop (Oryza sativa L cv. IR-36). Application of herbicides, in general, highly stimulated the population and activities of the target microorganisms, which resulted in a greater amount of atmospheric nitrogen fixation and phosphate solubilization in the rhizosphere soils of the test crop. The greater microbial activities subsequently augmented the mineralization and availability of nitrogen and phosphorus in the soil solution, which in turn increased the yield of the crop. Among the herbicides, oxyfluorfen was most stimulative followed by fluchloralin and oxadiazon in augmenting the microbial activities in soil. Butachlor also accentuated the mineralization and availability of nitrogen due to higher incitement of non-symbiotic N(2)-fixing bacteria in paddy soil. The grain and straw yields of the crop were also significantly increased due to the application of oxyfluorfen (20.2% and 21%) followed by fluchloralin (13.1% and 15.4%) and butachlor (9.1% and 10.2%), respectively. 相似文献
200.
Radhakrishnan Rokesh Banerjee Sanjukta Banerjee Srijoni Singh Vaishali Das Debabrata 《Journal of Material Cycles and Waste Management》2021,23(2):790-803
Journal of Material Cycles and Waste Management - Dwindling fossil fuels, and the rise in energy demand have urged us to explore alternative renewable energy forms. An integrated process of dark... 相似文献