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21.
Ambient air monitoring for suspended particulate matter was carried over a period of one year in some coal mining areas of the Raniganj coalfield. Concentrations of seven elements in suspended particulate matter were determined. The set of data obtained was analysed to determine the sources of trace elements by factor analysis. The data could be interpreted on the basis of five factors. These factors are attributed to various sources of particulate matter by noting the dependence of factors on the elements.  相似文献   
22.
In view of bio-inorganic importance, iron and zinc incorporated soybean oil based polymer was prepared by condensation polymerization of oil based fatty amide polyole, sebacic acid, zinc acetate and ferric chloride in a process initiated by sodium ethoxide. Microwave assisted synthesis was used throughout the reaction as it is ecofriendly and requires minimal usage of solvents. Physical techniques such as FT-IR and 1HNMR have been used to establish the structure of the polymers. Standard laboratory methods like acid value, saponification value, iodine value, specific gravity and viscosity were used to study the chemical diversity of each product. Thermo gravimetry/differential thermal analyzer was used to analyse the thermal behavior of polymer. The synthesized compounds were subjected to biological study. The observed fungicidal characteristics of synthesized compounds indicate that these compounds might be promising antifungal agents defining a new class of antimycotics. The polymers were used in preparation of films which can be used as protective packaging material of edible items.  相似文献   
23.
Scour is defined as the processes of removal of sediment particles from water stream bed by the erosive action of activated water, and also carries sediment away from the hydraulic structures. Scour is the main cause of pier failure. Numerous equations are available for estimating temporal and equilibrium scour depth. The present study describes the phenomenon of temporal scour depth variation at bridge piers and deals with the methods for its estimation. The accuracy of six temporal scour depth equations are also checked in this study. After graphical and statistical analysis, it was found that the relationship proposed by Oliveto and Hager (J Hydraul Eng (ASCE) 128(9):811–520, 2002) predicts temporal scour depth better than other equations. Three equations of equilibrium time of scour are also used for computing equilibrium time. Equilibrium time equation proposed by Choi and Choi (Water Environ J 30(1–2):14–21, 2016) gives better agreements with observed values.  相似文献   
24.
Socioecological theory suggests that between-group competition is an important factor affecting the nature of primate social relationships. Between-group encounters in macaques may involve female resource defense, male mate defense, and male resource defense. We observed between-group encounters in two groups (a forest group and a temple group) of bonnet macaques (Macaca radiata). We observed 102 encounters in 875 h of observation of the forest group (1.40 per 12-h day) and 58 encounters in 907 h of observation of the temple group (0.77 per 12-h day). Aggressive interactions between groups occurred in 32.4% and 29.3% of encounters in the forest and temple groups, respectively. Overall, we found little support for the female resource defense hypothesis. Females in both groups rarely participated aggressively in between-group encounters. We found support for the male mate defense hypothesis. For example, males of the forest group were more aggressive during encounters in the mating season than in the non-mating season. Males were also aggressive to females from their own group immediately following encounters. We also found partial support for the male resource defense hypothesis. Encounters in the forest group occurred in a feeding context more often than expected based on time budgets. Also, males in the temple group were more often aggressive in food-related encounters than in other encounters. The findings of this study suggest that socioecological models of primate social relationships need to distinguish male and female strategies during between-group encounters and integrate the resulting functional outcomes.Communicated by T. Czeschlik  相似文献   
25.
Comparative hepatic and renal toxicity of cadmium in male and female rats   总被引:3,自引:0,他引:3  
Rats (male and female) were exposed to 0.5 mg/kg and 1 mg/kg cadmium as cadmium chloride for 3 days and subsequently sacrificed for cadmium concentration and other biochemical variables indicative of hepatic and renal damage. The absorption of cadmium was supported by biochemical changes, which were significantly higher in females than in males. This could be due to higher rate of intestinal absorption of cadmium in females than males. Male and female rats both showed relatively higher cadmium concentration in kidneys than in liver. Female rats also showed the similar trend in tissue metal levels as compared to male rats. However, hepatic and renal histopathological observations showed that female rats suffered from severe hepatic injury like hydropic degeneration of hepatocytes, granulation, bile duct proliferation etc. In comparison to female rats, male rats did not show much remarkable changes. Renal damage was more prominent in female than male in the form of renal tubular damage; most of the tubular nuclei were pyknotic, congestion of the boundary of cortex and medulla etc. The results suggested that females were comparatively more vulnerable to the toxic effects of cadmium than males.  相似文献   
26.

Landslide poses severe threats to the natural landscape of the Lesser Himalayas and the lives and economy of the communities residing in that mountainous topography. This study aims to investigate whether the landscape change has any impact on landslide occurrences in the Kalsi-Chakrata road corridor by detailed investigation through correlation of the landslide susceptibility zones and the landscape change, and finally to demarcate the hotspot villages where influence of landscape on landslide occurrence may be more in future. The rational of this work is to delineate the areas with higher landslide susceptibility using the ensemble model of GIS-based multi-criteria decision making through fuzzy landslide numerical risk factor model along the Kalsi-Chakrata road corridor of Uttarakhand where no previous detailed investigation was carried out applying any contemporary statistical techniques. The approach includes the correlation of the landslide conditioning factors in the study area with the changes in land use and land cover (LULC) over the past decade to understand whether frequent landslides have any link with the physical and hydro-meteorological or, infrastructure, and socioeconomic activities. It was performed through LULC change detection and landslide susceptibility mapping (LSM), and spatial overlay analysis to establish statistical correlation between the said parameters. The LULC change detection was performed using the object-oriented classification of satellite images acquired in 2010 and 2019. The inventory of the past landslides was formed by visual interpretation of high-resolution satellite images supported by an intensive field survey of each landslide area. To assess the landslide susceptibility zones for 2010 and 2019 scenarios, the geo-environmental or conditioning factors such as slope, rainfall, lithology, normalized differential vegetation index (NDVI), proximity to road and land use and land cover (LULC) were considered, and the fuzzy LNRF technique was applied. The results indicated that the LULC in the study area was primarily transformed from forest cover and sparse vegetation to open areas and arable land, which is increased by 6.7% in a decade. The increase in built-up areas and agricultural land by 2.3% indicates increasing human interference that is continuously transforming the natural landscape. The landslide susceptibility map of 2019 shows that about 25% of the total area falls under high and very high susceptibility classes. The result shows that 80% of the high landslide susceptible class is contained by LULC classes of open areas, scrubland, and sparse vegetation, which point out the profound impact of landscape change that aggravate landslide occurrence in that area. The result acclaims that specific LULC classes, such as open areas, barren-rocky lands, are more prone to landslides in this Lesser Himalayan road corridor, and the LULC-LSM correlation can be instrumental for landslide probability assessment concerning the changing landscape. The fuzzy LNRF model applied has 89.6% prediction accuracy at 95% confidence level which is highly satisfactory. The present study of the connection of LULC change with the landslide probability and identification of the most fragile landscape at the village level has been instrumental in delineation of landslide susceptible areas, and such studies may help the decision-makers adopt appropriate mitigation measures in those villages where the landscape changes have mainly resulted in increased landslide occurrences and formulate strategic plans to promote ecologically sustainable development of the mountainous communities in India's Lesser Himalayas.

  相似文献   
27.
Environmental Science and Pollution Research - In the pursuit of constructing a sustainable world for all through the instrumental seventeen Sustainable Development Goals, the COVID-19 pandemic...  相似文献   
28.
Effect of soil amendments on sorption and mobility of metribuzin in soils   总被引:1,自引:0,他引:1  
Majumdar K  Singh N 《Chemosphere》2007,66(4):630-637
Metribuzin (4-amino-6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazin-5-one), is weakly sorbed to soil therefore, leaches easily to lower soil profiles. Soil amendments play a significant role in the management of leaching losses of pesticides. Therefore, present study reports the effect of organic manure and fly ash amendments on metribuzin downward mobility in sandy loam soil columns. Application of animal manure [T-1(OM) and T-2(OM)] and fly ash [T-1(FA) and T-2(FA)] at 2.5% and 5.0% levels increased the metribuzin retention in the soil. Freundlich constant [K(f)(1/n)] values of metribuzin for treatments T-1(OM) and T-2(OM) were 0.70 and 1.11, respectively, which were significantly higher than the value (0.27) in natural soil (T-0). The respective values for treatments T-1(FA) and T-2(FA) were 1.80 and 4.61. Downward mobility of metribuzin was studied in packed soil columns [300 mm (l)x59 mm (i.d.)]. Both the amendments significantly reduced the downward mobility of metribuzin and affected breakthrough time and maximum concentration of metribuzin in the leachate. Leaching losses of metribuzin were decreased from 97% in natural soil (T-0) column to 64% [T-1(OM)] and 42% [T-2(OM)] for animal manure-amended columns and 26% [T-1(FA)] to 100% [T-2(FA)] for fly ash-amended columns, as metribuzin did not leach out of 5% fly ash-amended column. Study indicates that both animal manure and fly ash were quite effective in reducing the downward mobility of metribuzin in packed soil columns of a sandy loam soil.  相似文献   
29.
Endosulfan (1,4,5,6,7,7-hexachloro-8,9,10-trinorborn-5-en-2,3-ylenedimethylsulphite) and quinalphos (O,O-diethyl O-quinoxalin-2-yl phosphorothioate) persistence and their effect on soil microarthropods were studied after repeated applications in cotton fields. Dissipation behavior of insecticides after repeated applications was observed from 78 to 292 days after the first insecticide treatment. At any given time the concentrations of endosulfan beta residues were always higher as compared to endosulfan alpha. From 78 to 85 days, 5.0% and 20.4% decrease in alpha and beta endosulfan residues was observed, respectively. Endosulfan beta isomer decreased up to 93.0% in 292 days. Endosulfan sulfate was detected as a major metabolite in the soil samples. Total endosulfan residues decreased by 86.6% from 78 to 292 days. The amounts of quinalphos residues were less as compared to endosulfan at any given time. The residues observed after 78 days of application were 0.88 ng g-1 d wt. soil. At the end of 145 days, a 35.0% decrease in quinalphos residue was observed, which decreased further by 50.9% in 292 days. Among the soil microarthropods studied, Acarina was more sensitive to the applied insecticides as compared to Collembola. Three days after the last treatment, up to 94.5% (p < 0.01) and 71.2% (p < 0.05) decrease in Acarina population was observed in endosulfan and quinalphos treated fields, respectively, compared to control field. In general, no noticeable change in Collembola population was observed after the insecticide treatments.  相似文献   
30.
Juwarkar AA  Nair A  Dubey KV  Singh SK  Devotta S 《Chemosphere》2007,68(10):1996-2002
This research focuses on column experiments conducted to evaluate the potential of environmentally compatible rhamnolipid biosurfactant produced by Pseudomonas aeruginosa strain BS2 to remove heavy metals (Cd and Pb) from artificially contaminated soil. Results have shown that di-rhamnolipid removes not only the leachable or available fraction of Cd and Pb but also the bound metals as compared to tap water which removed the mobile fraction only. Washing of contaminated soil with tap water revealed that approximately 2.7% of Cd and 9.8% of Pb in contaminated soil was in freely available or weakly bound forms whereas washing with rhamnolipid removed 92% of Cd and 88% of Pb after 36 h of leaching. This indicated that di-rhamnolipid selectively favours mobilization of metals in the order of Cd>Pb. Biosurfactant specificity observed towards specific metal will help in preferential elution of specific contaminant using di-rhamnolipid. It was further observed that pH of the leachates collected from heavy metal contaminated soil column treated with di-rhamnolipid solution was low (6.60-6.78) as compared to that of leachates from heavy metal contaminated soil column treated with tap water (pH 6.90-7.25), which showed high dissolution of metal species from the contaminated soil and effective leaching of metals with treatment with biosurfactant. The microbial population of the contaminated soil was increased after removal of metals by biosurfactant indicating the decrease of toxicity of metals to soil microflora. This study shows that biosurfactant technology can be an effective and nondestructive method for bioremediation of cadmium and lead contaminated soil.  相似文献   
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