خيارات البحث
النتائج 1661 - 1670 من 3,243
Linear Discriminant Function Analysis for the Different Characters of Pigeonpea (Cajanus Cajan (L.) Millsp) Accessions
2015
Kumar S. T. Pavan | Avinalappa H. H. | Tuppad G. B. | Kamei Adam
Variations in different characters of the pigeonpea were studied using 122 accessions under rainfed condition during 2013. The characters considered viz., days to 50 per cent flowering, plant height (cm), days to physiological maturity, pods per plant, pod bearing length (cm), seeds per pod, 100 seed weight (g) and seed yield per plant (g) were used for the analysis. K-means cluster analysis was carried out based on the mean values and classified 122 accessions into four distinct clusters. The cluster-I (14 accessions), cluster-II (40 accessions), cluster-III (17 accessions) and in fourth cluster 51 accessions were distinctly classified. It is found that, days to physiological maturity, pods per plant, days to 50 per cent flowering and pod bearing length (cm) were significant discriminating characters. The stepwise discriminant analysis showed that pods per plant and days to physiological maturity were highly discriminating characters and these two characters were explained by the 98.8 percent variation in the accessions studied and these accessions were classified 97.5 percent correctly in the four clusters.
اظهر المزيد [+] اقل [-]Microfiltration, Groundwater Remediation and Environmental Engineering Science - A Scientific Perspective and a Far-reaching Review
2015
Palit Sukanchan
The environmental engineering paradigm is surpassing one visionary frontier over another. Mankind today stands in the midst of optimism and scientific vision. The world of challenges is befitting to the progress of human civilization. The road to progress in implementation of environmental sustainability is vast, varied and ground-breaking. In such a crucial juncture of history and time, the need of application of environmental engineering science is of immense and effective importance. Microfiltration and other membrane separation processes are the ultimate avenues of scientific and engineering progress. Science and engineering are moving steadfastly towards a newer scientific generation and a newer scientific understanding. The step forward is painstaking as regards zero-discharge norms. Environmental regulations and stringent environmental restrictions have plunged the scientific community to devise paths towards progress. Industrial pollution control, wastewater treatment and application of microfiltration are the primordial issues targeted in this treatise. The focus towards addressing novel separation processes and novel environmental engineering techniques stands today as a formidable challenge in the road towards zero-discharge norms. The author diligently and lucidly brings forward to the scientific community the immense rigorous and effective challenges in the application of microfiltration as an efficient membrane separation process. History of environmental engineering science, history of science and technology needs to be readdressed and reassessed in the future application of membrane science as an efficient separation technique.
اظهر المزيد [+] اقل [-]Study on Carbon Dioxide Emission Performance in the Guangdong Province Based on the Malmquist-Luenberger Index
2015
Guo Hao | Wang Dong | Yu Pa | Lin Lianlian
Based on academic studies of carbon dioxide emissions, an environmental data envelopment analysis (DEA) model, including undesirable carbon dioxide emissions, is reported here. MaxDEA software was used to calculate carbon emissions performance in the Guangdong Province of China. Our findings revealed that in order to achieve the same level of economic development achievements, carbon emission performance and carbon dioxide pollution are negatively correlated. Moreover, pollution prevention and protection measures can decrease the degree of carbon dioxide pollution. Here, we observed that increasing economic development has a positive effect on carbon emission performance and the greater the energy demand, the higher the degree of pollution. Technological change is a decisive factor influencing carbon emissions performance. By employing technological innovations, energy utilization efficiency and the resulting level of environmental pollution can be greatly improved
اظهر المزيد [+] اقل [-]Variations in Culturable Terrestrial Bacterial Communities and Soil Biochemical Characteristics Along an Altitude Gradient Upstream of the Shule River, Qinghai-Tibetan Plateau
2015
Baogui Zhang | Wei Zhang | Guangxiu Liu | Tuo Chen | Gaosen Zhang | Xiukun Wu
Variations in the culturable terrestrial bacterial communities and soil biochemical parameters along an altitude gradient (from 1260m to 4111m) upstream of the Shule River, Qinghai-Tibetan Plateau, were investigated. The results showed that the number of cultivable bacteria varied between 0.4×107 and 3.3×107 CFU/g, with an average of 1.6×107 CFU/g. 168 isolates from these soils were clustered into 34 groups by amplified ribosomal DNA restriction analysis (ARDRA). These groups are affiliated to 15 genera that belong to six taxa, a-Proteobacteria, b-Proteobacteria, g-Proteobacteria, Actinobacteria, Firmicutes and Bacteroides, of which Bacillus and Arthrobacter were the dominant species at the level of the genus. The relative abundance of Arthrobacter increased significantly at high altitude. Correlation analysis showed that the total number of culturable bacteria in the soils decreased first and then increased below 3000m, and these trends significantly positively correlated to the soil organic C, total N and the activities of soil sucrase, and positively correlated to the activities of soil urease and catalase. However, when the altitude exceeded 3000m, cultivable bacterial number dramatically declined, although soil organic carbon, total nitrogen and enzyme activities were relatively high. While the diversity index of bacteria increased along with the increased altitude as a whole and there existed a significantly positive correlation between altitude and bacteria diversity. Together, these results illustrated that culturable bacterial numbers were mainly influenced by soil biochemical properties while bacterial diversity was mainly influenced by altitude in this region.
اظهر المزيد [+] اقل [-]Ecology and Evolution of Nest Parasitism in Indian Cuckoo
2015
Sharma R. K. | Goyal A. K. | Sharma Manju
Nest parasitism is a common phenomenon in many species of birds in which a female of one species lays her eggs in the nest of another species to be hatched and cared by the hosts. The nest parasitism evolved initially as a facultative strategy to use the nest of one species which has raised its brood or deserted nests and then further advanced into parasitism. The host species feed on a wide spectra of food resources, especially rich in protein and are insectivores, carnivores or omnivores in contrast to the very restrictive feeding habits of the parasite species. Parasitism cost for the host is often high which favour the evolution of host defence leading to a parallel evolution between adaptation and counter adaptation of host-parasite interaction. The understanding of breeding biology and ecology of nest parasitism provides important information for the population management of host and parasitic species to devise very specialized conservation strategies for the delicate interaction in the quickly evolving environmental scenario.
اظهر المزيد [+] اقل [-]Evaluation of Water Quality Using Principal Component Analysis
2015
An Shuquan | Xie Xiufan | Ma Ying
Principal component analysis is a way to reduce original dimension, to make multiple variables into a few comprehensive index. According to the characteristics of water quality evaluation model, principal component analysis method is developed to evaluate surface water quality using SPSS software at representative sections. By the combination of variables index, adjusting the combinatorial coefficient to make the new variables representative independent. The process is introduced in the paper in detail. The results indicate that the principal component model is suitable for water quality evaluation. By analysis, it is important to pay attention to bring into effective measures for pollution control.
اظهر المزيد [+] اقل [-]Oxidation of Reduced Inorganic Sulphuric Compounds in Simulated Desulphurization Wastewater by Thiobacillus Thioparus
2015
Dong Yingbo | Lin Hai
This paper is aimed to investigate the oxidation ability of the bacteria (Thiobacillus thioparus, Z-2) and the biological oxidation mechanism and oxidation kinetics on the reduced inorganic sulphuric compounds in sodium-process desulphurization wastewater. Results showed that the Z-2 bacteria have high oxidation activity in the high-salt environment after acclimation, and the oxidation percentage of reduced inorganic sulphuric compounds reached 95% and the chemical oxygen demand (COD) reduced from 18000mg/L to 2000 mg/L in the high-salt environment. This showed that the Z-2 bacteria have strong salt resistance and high oxidation activity. In addition, ion chromatography analysis confirmed that Z-2 bacteria were beneficial for the oxidation of reduced sulphur. A biological oxidation model was constructed by measuring the enzyme activity of the oxidation process. The results indicated that direct and indirect oxidation processes were both involved in biological oxidation. The kinetic parameters of Vmax (21.38 µM/min) and Km (79.04 µM) were obtained through biological oxidation kinetic experiments.
اظهر المزيد [+] اقل [-]A Study on the Quantitative Measurement Method of Organoleptic Chromaticity for Sandy Water
2015
Yu Yali | Pu Xunchi | Li Ran | Jiang Hong | Li Yong
Water landscape quality is an important part of environmental quality. However, in the environment impact assessment, there is no method at present that can quantitatively assess the colour changes of the water landscape affected by sediments. This paper presents a conception of organoleptic chromaticity according to the engineering requirement. Water organoleptic chromaticity is defined as a water chromaticity which is caused by both soluble substances and insoluble substances and observed directly by naked eyes. Using the spectrophotometry, it was found that the maximum absorption peak of coloured-turbid water occurred at 350nm which is defined as the characteristic wavelength of water organoleptic chromaticity. Based on the standard turbidity and chromaticity solutions, the metric system of organoleptic chromaticity was established. The absorbance of water with different turbidity and chromaticity showed that it is linear with the organoleptic chromaticity. Measuring the organoleptic chromaticity of different sandy waters, the results demonstrated that the metric system of organoleptic chromaticity could apply to the quantitative assessment of landscape quality for engineering sandy water in practical engineering.
اظهر المزيد [+] اقل [-]Foliar Carbon Isotope Discrimination and Water Sources of Mangrove Forests Along Natural Soil Salinity Gradients and Implications for Their Distribution Pattern
2015
Huang Minshen | Li Qing | Le Tongchao | Tan Fanglin
Field species composition investigation showed an obvious zonation pattern of three main species of mangrove forests along Zhangjiang estuary. Aegiceras corniculata was mostly found in upstream and Avicennia marina mainly distributed in intermediate and downstream, while Kandelia obovata grows across the estuary and a majority in upstream and intermediate. Foliar carbon isotope discrimination of the three species, decreased from both upstream to downstream and wet to dry season, indicated their increased water use efficiency to increased soil salinity and decreased availability of freshwater. Increased ocean water uptake ratio (increased d18O values) of all the three species from upstream to downstream further indicated their adaptations to decreased availability of freshwater. Decreased responses of water use efficiency in response to ocean water uptake ratio were also observed in all the three species. Significant relations observed in Avicennia marina and Kandelia obovata may indicate their higher adaptations to increased ocean water uptake than Aegiceras corniculata with no significant relationships, which may explain why the distribution of Aegiceras corniculata was confined to the low salinity area. All the results above, implicated that the zonation pattern of mangrove forests were linked to their physiological process on how water use efficiency responded to change of ocean water uptake ratio.
اظهر المزيد [+] اقل [-]Analyses of Diversion Water Input’s Influence on Water Quality of Dahuofang Reservoir
2015
Meng Fanbin | Li Haifu | Su Fangli | Wang Tieliang
This paper selected Dahuofang Reservoir as the research area, analysed the relationship between water quality and diversion water input, determined the right weight of each index affected the water quality based on correlation analysis and entropy weight method. The results showed that after the diversion water input, the DO is 6739.17t, CODMn is 1735.00t, BOD is 625.83t, NH3-N is12.07t, TP is 12.5t, TN is 1860.75t, coliform-group is 1.38 ×1015. The correlation between the indexes of DO, CODMn, BOD, TN, coliform-group and water quality is significant after diversion water input. The affected right weights of the amount of TN, coliform-group and NH3-N input are more than 0.1, the highest right weight is of TN input (0.1804), followed by coliform-group (0.1173) and NH3-N (0.1165) | the most slight one is TP (0.0164). In terms of comprehensive analysis, the influence of each index of diversion water input on water quality of Dahuofang reservoir, the order is TN>coliform-group>NH3-N>BOD>DO>CODMn>TP.
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