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41.
This study was conducted to assess the existing concentration of 17β-estradiol(E2)in the surface water samples collected from rivers and lakes around Klang Valley,Malaysia.E2,which is a natural feminizing chemical produced in female organisms,regularly used to compare with other environmental estrogens because they behave similarly and react effectively as a hormone at a very low concentration.It was found that the average concentration of E2 in the aquatic environment of Klang Valley was(14.08 ±3.67)pg/mL,which was 14 times higher than those in the Japanese aquatic environment in this study.The river system had the average concentration of(20.02±5.26)pg/mL while the lake had an average concentration of(5.91±3.39)pg/mL.The E2 concentration was presumed high if the sources occurred nearby the area.Current levels of E2 in the aquatic environment may possess threats to existing aquatic organisms.Since high level of E2 has been discovered in the aquatic environment around Klang Valley,further studies and monitoring of E2 and other EDCs concentrations are needed to determine their levels in Malaysian aquatic environment and help to control these chemicals pollution in the aquatic environment.  相似文献   
42.

Occurrence of drought, as an inevitable natural climate feature, cannot be ceased while happening. However, costs of the consequences could be alleviated using mature scientific integrated approaches. To reduce the amount of damage, it is required to provide “Contingency” and “Mitigation” action plans. For this reason, development of efficient operating instructions for various regions based on weather conditions and field studies is needed as well as having a sophisticated understanding of socioeconomic situations. This paper describes an approach to provide the first national agricultural drought risk management plan for a river basin in Iran country as a pilot. The study lasted for 3 years as a national technical research project for the “soil conservation and watershed management research institute.” To reach the objectives, besides holding workshops and specialized think-tank meetings, field researches were done. Based on the socioeconomic data sources in the basin and the results of meetings by participation of local managers and residents, the final plan was developed. Moreover, in order to carry out this research, different climatic, agricultural and local information were collected in the watershed. In the next steps, potential risks and vulnerabilities of various agricultural sectors due to the hazard were evaluated. In this study, a nine-step approach to develop an agricultural drought risk management plan proposing different scientific–managerial phases based on the latest experts’ opinions, released international scientific best practices, and existing conditions governing the region was followed. With respect to the average income of US$ one million from agriculture and animal husbandry in the river basin, total drought loss varies from US$ 86,000 to US$ 258,000 for a range of light to very intense drought conditions, respectively. The setup of these nine executive phases defined monitoring, forecasting, and warning steps in working teams and managed the subprograms in partnership with stakeholders and decision-makers to mitigate the rate of drought damage from 30 to 47% (depending on the severity of the drought condition).

  相似文献   
43.
A chelating resin is prepared by condensation polymerization of aniline with formaldehyde and characterized by Fourier transform infrared spectrometer, elemental analysis and thermogravimetric analysis and studied for the preconcentration and determination of trace Molybdate ion from environmental water sample using inductive couple plasma atomic emission spectroscopy. The optimum pH value for sorption of the metal ion was 5. The sorption capacity of functionalized resin is 3.1 mg/g. The chelating sorbent can be reused for 20 cycles of sorption-desorption without any significant change in sorption capacity. The best desorption of the metal ions from resin was obtained by 0.5 mol/L nitric acid as eluting agent. The profile of molybdenum uptake on this sorbent reflects good accessibility of the chelating sites in the aniline-formaldehyde. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. The equilibrium adsorption data of Molybdate ion modified resin were analyzed by five isotherm models such as Langmuir, Freundlich and Temkin. Langmuir isotherm parameters obtained from the four Langmuir linear equations by using linear method. Based on the Langmuir isotherm analysis, the monolayer adsorption capacity was determined to be 4.03 mg/g at 20 °C. The method was applied for molybdenum ions determination from river water sample.  相似文献   
44.
Nannorrhops ritchiana ( Mazari Palm) is a distinctive flora growing in the Saharo-Sindian region. It is well distributed on the ultramafic soil, derived from the Bela Ophiolite in the Khuzdar District, Balochistan, Pakistan. Quantitative estimation of Ca, Mg, Fe and Ni in soil and plant ash has been carried out. The constituents of plant ash have been discussed in relation to soil chemistry, pH, climate, mobility, average abundance in plant ash and exclusion mechanism of the flora. Relationship among Ca, Mg, Fe and Ni has been established using scattergrams to evaluate the biogeochemistry of the plant. High contents of Mg and high coefficient of biological absorption allow it to be classed as Mg-flora. Both Ca and Fe appeared to be antagonistic to Mg. The metal assemblage of N. ritchiana nicely reflected the nature of the bed rock as being serpentinized ultramafic, and its corresponding soils. Good exclusion mechanism of N. ritchiana did not allow it to absorb high Ni from the soil. Relatively high concentrations of Ni in N. ritchiana from the Baran Lak area can be used to localize Ni-mineralization in the study area. Statistical analyses, such as minimum, maximum, mean, mode, median, standard deviations, and coefficient of correlation, were also made to improve raw geochemical data and interpretations.  相似文献   
45.
Nannorrhops ritchiana (Mazari Palm) is a distinctive flora growing in the Saharo-Sindian region. It is well distributed on the ultramafic soil, derived from the Bela Ophiolite in the Khuzdar District, Balochistan, Pakistan. Quantitative estimation of Ca, Mg, Fe and Ni in soil and plant ash has been carried out. The constituents of plant ash have been discussed in relation to soil chemistry, pH, climate, mobility, average abundance in plant ash and exclusion mechanism of the flora. Relationship among Ca, Mg, Fe and Ni has been established using scattergrams to evaluate the biogeochemistry of the plant. High contents of Mg and high coefficient of biological absorption allow it to be classed as Mg-flora. Both Ca and Fe appeared to be antagonistic to Mg. The metal assemblage ofN. ritchiana nicely reflected the nature of the bed rock as being serpentinized ultramafic, and its corresponding soils. Good exclusion mechanism ofN. ritchiana did not allow it to absorb high Ni from the soil. Relatively high concentrations of Ni inN. ritchiana from the Baran Lak area can be used to localize Ni-mineralization in the study area. Statistical analyses, such as minimum, maximum, mean, mode, median, standard deviations, and coefficient of correlation, were also made to improve raw geochemical data and interpretations.  相似文献   
46.
Urban areas are of paramount significance to both the individuals and communities at local and regional scales. However, the rapid growth of urban areas exerts effects on climate, biodiversity, hydrology, and natural ecosystems worldwide. Therefore, regular and up-to-date information related to urban extent is necessary to monitor the impacts of urban areas at local, regional, and potentially global scales. This study presents a new urban map of Eurasia at 500 m resolution using multi-source geospatial data, including Moderate Resolution Imaging Spectroradiometer (MODIS) data of 2013, population density of 2012, the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) nighttime lights of 2012, and constructed Impervious Surface Area (ISA) data of 2010. The Eurasian urban map was created using the threshold method for these data, combined with references of fine resolution Landsat and Google Earth imagery. The resultant map was compared with nine global urban maps and was validated using random sampling method. Results of the accuracy assessment showed high overall accuracy of the new urban map of 94%. This urban map is one product of the 20 land cover classes of the next version of Global Land Cover by National Mapping Organizations.  相似文献   
47.
Biosorption using activated sludge biomass (ASB) as a potentially sustainable technology for the treatment of wastewater containing different metal ions (Cd(II), Pb(II) and Zn(II)) was investigated. ASB metal uptake clearly competed with protons consumed by microbial biomass compared with control tests with non‐activated sludge biomass. Biosorption tests confirmed maximum exchange between metal ions and protons at pH 2.0–4.5. It was revealed by the study that the amount of metal ions released from the biomass increased with biomass sludge concentration. The result showed that maximum absorption of metal ions was observed for Cd(II) at pH 3.5, Pb(II) at pH 4.0, and pH 4.5 for Zn(II) ions. The maximum absorption capacities of ASB for Cd(II), Pb(II) and Zn(II) were determined to be 59.3, 68.5 and 86.5%, respectively. The biosorption of heavy metals was directly proportional to ASB stabilization corresponding to a reduction in heavy metals in the order of Cd < Pb < Zn. The order of increase of biosorption of metal ions in ASB was Zn(II) < Pb(II) < Cd(II), and this was opposite to that of non active sludge. The results indicate that ASB is a sustainable tools for the bioremediation of Cd(II), Pb(II) and Zn(II) ions from industrial sludge and wastewater treatment plants.  相似文献   
48.
Cosmic energy equation represents the law of conservation of energy in the region expanding with time as the universe expands. It gives the evolution of kinetic and correlation potential energy with time in a cluster expanding as the universe expands. To understand the clustering of galaxies under the influence of gravitational force, cosmic energy equation is of great help. We use cosmic energy equation for extended structures (galaxies with halos) to analyse the gravitational galaxy clustering in different ways. We try to understand the influence of expansion on the clustering by deriving the relation between correlation parameter b V and scale factor R. We also derive the relation between the peculiar kinetic energy K and correlation parameter to know that when peculiar kinetic energy dominates over the kinetic energy of galaxies due to expansion. Besides, the evolution of specific heat and energy provides the information regarding the different states of clustering.  相似文献   
49.
We consider periodic halo orbits about artificial equilibrium points (AEP) near to the Lagrange points L 1 and L 2 in the circular restricted three body problem, where the third body is a low-thrust propulsion spacecraft in the Sun–Earth system. Although such halo orbits about artificial equilibrium points can be generated using a solar sail, there are points inside L 1 and beyond L 2 where a solar sail cannot be placed, so low-thrust, such as solar electric propulsion, is the only option to generate artificial halo orbits around points inaccessible to a solar sail. Analytical and numerical halo orbits for such low-thrust propulsion systems are obtained by using the Lindstedt Poincaré and differential corrector method respectively. Both the period and minimum amplitude of halo orbits about artificial equilibrium points inside L 1 decreases with an increase in low-thrust acceleration. The halo orbits about artificial equilibrium points beyond L 2 in contrast show an increase in period with an increase in low-thrust acceleration. However, the minimum amplitude first increases and then decreases after the thrust acceleration exceeds 0.415 mm/s2. Using a continuation method, we also find stable artificial halo orbits which can be sustained for long integration times and require a reasonably small low-thrust acceleration 0.0593 mm/s2.  相似文献   
50.
The investigation of the impact of different forms of nitrogen fertilizer (NO3-N and NH4-N) on microbial parameters, enzyme activities and phytotoxicity in a petroleum-contaminated soil was evaluated by an incubation study. The tested enzymes, microbial activity and seed germination index showed different patterns in response to both petroleum and nitrogen fertilizer addition and time of incubation. The results apparently showed that the contamination of soil with petroleum has a negative effect on soil ecosystem. Nitrogen fertilizer could improve inhibition of petroleum hydrocarbons in soil. Nevertheless, nitrogen fertilizer had no significant effect on urease activity in the petroleum-contaminated soil. As compared to NO3-N, the addition of NH4-N to the soil resulted in a greater impact on soil performance as attested by the recovery of the soil germination capability and higher values of the respiration. The application of nitrogen fertilizer may be suggested as a good strategy for restoring soils in regions affected by the same problem.  相似文献   
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