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301.
Introduction Nitromusksarewidelyusedassyntheticfragranceingredientsinformulationofsoaps,laundrydetergents,lotions,andbody careproducts,andsoon.Thecommercial anddomesticuseanddischargeofthesecompoundsfrommunicipalsewagesystemshaveledtotheirubiquitousoccurr…  相似文献   
302.
In this study, the aqueous extract of leaves of the plant cock's comb (Celosia argentea) was fractioned into five batches using n-hexane, dichloromethane, ethyl acetate, and n-butanol, respectively. High performance liquid chromatography analysis of the methanol re-dissolved residues of 3 polar fractions, including dichloromethane, ethyl acetate, and n-butanol separately which exhibited altogether 12 compounds identified as 4-hydroxycinnamic acid (p-coumaric acid), 4-hydroxybenzoic acid, protocatechuic acid, caffeic acid, m-coumaric acid, gallic acid, 4-hydroxybenzaldehyde, m-hydroxybenzaldehyde, 2,4-dihydroxybenzoic acid, pyrogallol, 3,5-dihydroxybenzoic acid, and genetic acid was categorized by retention time using known compounds. Similarly, the mass confirmation of most of the identified compounds was achieved by injecting 20 µl of composite sample of these three polar fractions into liquid chromatography–mass spectrometry. Similarly, the physiochemical analysis of C. argentea aqueous extract showed the presence of various constituents such as phenols, flavonoids, tannins, and glycosides. All four organic fractions were examined for phytotoxicity against Lepidium sativum. Analysis of variance showed significant differences among these fractions against germination and growth of L. sativum. Further allelopathic effects appeared to be concentration dependent. Thus, C. argentea may prove effective as a substitute of herbicides to control the weeds like L. sativum from attacking crops and to protect the environment from the health hazard effects of herbicides.  相似文献   
303.
It has been repeatedly stressed that the biological effectiveness of chromium depends entirely on its oxidation state. The present work compares the histological effects of ingested trivalent and hexavalent chromium compounds on the mouse testes. The results showed comparable data of food consumption and gain in body weight. Both compounds produced ambiguous levels of degeneration in the outmost cellular layers of a number of seminiferous tubules, reduced the number of spermatogonia per tubule and the sperm count, and caused significant increases in the percentage of morphologically abnormal sperms. Generally, all these effects were more pronounced in animals which ingested the hexavalent chromium.  相似文献   
304.
This paper presents a case study of land-use/land-cover (LULC) changes from 1975 to 2014 in the central highlands of Ethiopia and traces out its impact on socioeconomic conditions of the local community in the study area. We used four time series Landsat satellite images, that is, Landsat MSS (1975), Landsat Thematic Mapper (1986), Enhanced Thematic Mapper (2000), and Landsat 8 OLI scenes (2014), to investigate the changes in LULC. In addition, individual interviews with 51 randomly selected households, discussions with focus group and key informants, and field observations were also incorporated for the study. The image classification indicated four categories of LULC classes: Natural forest, eucalyptus plantations, cropland/settlements, and grasslands. Between 1975 and 2014, cropland/settlements and eucalyptus plantations considerably increased, whereas grassland cover drastically decreased. According to the results, the area under cropland/settlements and eucalyptus plantations increased by 62 and 335%, respectively, with 74% concomitant decrease in the area of grasslands in the same period. Survey results showed that deterioration of soil fertility (41.2%) followed by shortage of land (35.3%) is the major constraint for crop production for poor farmers in the study area. However, better-off farmers ranked deterioration of soil fertility (64.7%) followed by lack of credit (17.6%) as priority constraints for crop production. Interviews mainly focused on selected women group revealed that the expansion of eucalyptus in the area greatly curbed the burdens of collecting fuel woods from long distances in the past. The availability of too many religious holidays (on average 16 days/month) directly or indirectly contributes to the current seasonal food shortages of the community. Generally, our results show that the community in the study area is beset with a host of social, economic, and institutional challenges. As a result, majority of the farming households are destitute, unable to make a livelihood from their small plot of land and live in absolute poverty. Therefore, in light of these finding, it is imperative that timely interventions by government and other development stakeholders are needed to come to grips with problems of soil fertility, land-use change, and food insecurity in the study area.  相似文献   
305.
A study on chemical, morphology, and thermal analysis of cultivated pineapple leaf fibres (PALF) were carried out. The chemical compositions were determined by using Technical Association Pulp and Paper Industries standards. Fourier Transform-Infrared Spectroscopy analysis of PALF detect sharp band at 1,733?cm?1, due to the absorption of carbonyl stretching of ester and carboxyl groups which is most abundant in pineapple leaf hemicelluloses. Cell wall ultra structure of PALF was studied by using Transmission electron microscopy. Transmission electron micrograph confirmed that cell wall structure of PALF consists of middle lamella, primary wall and secondary wall including S1, S2 and S3 layers. X-Ray Diffraction indicated that PALF have crystalline nature. Thermal analysis of PALF shows that T10% and T50% weight loss occurred at temperature of 212 and 306?°C respectively. Differential Scanning Calorimetry of PALF showed the broad endothermic peak at a temperature of 80?°C. The relationships between these properties were discussed and relate it with industrial application of pineapple leaf fibers.  相似文献   
306.
The implications of a potential ban on shrimp imports by the US from countries that do not utilize the Turtle Excluder Device on commercial shrimp nets is explored in this paper. A Linear Expenditure System (LES) was used to determine the own-price elasticities of demand for shrimp imports. The system of estimated equations was then solved for quantity levels under assumptions made about the trade restrictions, resulting in a set of prices for those import levels. These estimated prices were then used to estimate the compensating variation impact of the trade restrictions. Findings suggest that the environmental regulation would have a negative impact on US consumers, but the magnitude of that effect depends on assumptions made regarding the distribution of US imports after the trade restriction is imposed.  相似文献   
307.
308.
Environmental Science and Pollution Research - Binary composite of zerovalent iron and titanium dioxide (Fe0/TiO2) was synthesized for the catalytic removal of dichlorophene (DCP) in the presence...  相似文献   
309.
Toxicity,degradation and analysis of the herbicide atrazine   总被引:3,自引:0,他引:3  
Excessive use of pesticides and herbicides is a major environmental and health concern worldwide. Atrazine, a synthetic triazine herbicide commonly used to control grassy and broadleaf weeds in crops, is a major pollutant of soil and water ecosystems. Atrazine modifies the growth, enzymatic processes and photosynthesis in plants. Atrazine exerts mutagenicity, genotoxicity, defective cell division, erroneous lipid synthesis and hormonal imbalance in aquatic fauna and nontarget animals. It has threatened the sustainability of agricultural soils due to detrimental effects on resident soil microbial communities. The detection of atrazine in soil and reservoir sites is usually made by IR spectroscopy, ELISA, HPLC, UPLC, LC–MS and GC–MS techniques. HPLC/LC–MS and GC–MS techniques are considered the most effective tools, having detection limits up to ppb levels in different matrices. Biodegradation of atrazine by microbial species is increasingly being recognized as an eco-friendly, economically feasible and sustainable bioremediation strategy. This review presents the toxicity, analytical techniques, abiotic degradation and microbial metabolism of atrazine.  相似文献   
310.
Environmental Science and Pollution Research - The construction of green finance index is a three-tiered process that involves macroeconomic, ecological, and monetary indicators. Therefore, this...  相似文献   
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