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91.
Seyed Hamidreza Sadeghi Shirko Ebrahimi Mohammadi Vijay P. Singh Kamran Chapi 《Environmental monitoring and assessment》2017,189(5):238
The temporal variability of phosphorus (P) transport and the relationships between discharge, suspended sediment concentration and particulate (PP), and soluble (SP) phosphorus were examined. The study was conducted at the event scale in seven tributaries of the Zarivar Lake watershed in Kurdistan Province (Iran) from March 2011 to April 2012. Based on eight runoff events, 82% of the total P was the PP carried out by suspended sediment. Results showed a high variability of P transport during different runoff events. It was found that soil erosion was the source of the high P load. For all tributaries, PP was linearly related to both discharge and suspended sediment concentration. However, the relationships of SP and PP with discharge and suspended sediment concentration showed different hysteresis patterns. The relationship between PP and discharge was generally characterized by a clockwise pattern (i.e., lower part contribution of the sub-watersheds) but the patterns between SP and discharge were mainly anticlockwise (i.e., upper part contribution of the sub-watersheds or perhaps due to a subsurface flow contribution). 相似文献
92.
Characterization of ionic composition of TSP and PM10 during the Middle Eastern Dust (MED) storms in Ahvaz, Iran 总被引:1,自引:0,他引:1
Shahsavani A Naddafi K Jaafarzadeh Haghighifard N Mesdaghinia A Yunesian M Nabizadeh R Arhami M Yarahmadi M Sowlat MH Ghani M Jonidi Jafari A Alimohamadi M Motevalian SA Soleimani Z 《Environmental monitoring and assessment》2012,184(11):6683-6692
Because of the recent frequent observations of major dust storms in southwestern cities in Iran such as Ahvaz, and the importance of the ionic composition of particulate matters regarding their health effects, source apportionment, etc., the present work was conducted aiming at characterizing the ionic composition of total suspended particles (TSP) and particles on the order of ~10?μm or less (PM(10)) during dust storms in Ahvaz in April-September 2010. TSP and PM(10) samples were collected and their ionic compositions were determined using an ion chromatography. Mean concentrations of TSP and PM(10) were 1,481.5 and 1,072.9?μg/m(3), respectively. Particle concentrations during the Middle Eastern Dust (MED) days were up to four times higher than those in normal days. Ionic components contributed to only 9.5% and 11.3% of the total mass of TSP and PM(10), respectively. Crustal ions were most abundant during dust days, while secondary ions were dominant during non-dust days. Ca(2+)/Na(+) and Cl(-)/Na(+) ratios can be considered as the indicators for identification of the MED occurrence. It was found that possible chemical forms of NaCl, (NH(4))(2)SO(4), KCl, K(2)SO(4), CaCl(2), Ca(NO(3))(2), and CaSO(4) may exist in TSP. Correlation between the anionic and cationic components suggests slight anion and cation deficiencies in TSP and PM(10) samples, though the deficiencies were negligible. 相似文献
93.
Human milk is usually the only source of food for infants during the first 4 to 5 months of their life. Maternal environmental
mercury exposure is directly related to fish consumption or amalgam filling. In this research, 38 human milk samples were
collected from mothers of Lenjan area who were not occupationally exposed with mercury. Mercury concentration in human milk
was determined by AMA254 Mercury Analyzer. A level of mercury was examined in relation to somatometric, demographic and dental
amalgam parameters. Obtained results showed that only dental amalgam significantly increased the mercury level in human milk
(p < 0.001). The mean mercury concentrations in milk of mothers without teeth fillings (n = 13), with one to three teeth fillings (n = 10), and four to eight teeth fillings (n = 15) were 2.87, 5.47, and 13.33 μg/l, respectively. The result of this study also showed a positive correlation of mercury
milk levels with the number of teeth fillings of the mother (p < 0.05, r = 0.755). The estimated weekly intake of mercury of a breastfed infant in this study was, in some cases, higher than provisional
tolerance weekly intake recommended by FAO/WHO, which pose a threat to their health. 相似文献
94.
Borhan Mansouri Afshin Maleki Seyed Ali Johari Behzad Shahmoradi Ebrahim Mohammadi 《Chemistry and Ecology》2017,33(4):295-308
In current research, the combined effects of copper oxide nanoparticles (CuO NPs) and titanium dioxide nanoparticles (TiO2 NPs) on the histopathological anomalies of gill and intestine tissues in common carp (Cyprinus carpio) were studied. Common carp were exposed to TiO2 NPs (10.0?mg L?1), CuO NPs (2.5 and 5.0?mg L?1), and mixture of TiO2 NPs (10.0?mg L?1)?+?CuO NPs (2.5 and 5.0 mg?L?1) for two periods of exposure (10 and 20 days) and recovery (30 and 40 days). The most common histopathological anomalies in the gill of common carp such as hyperplasia, oedema, curvature, fusion, aneurism, and necrosis were observed. The synergistic effect of co-existing TiO2 NPs and CuO NPs reduced the length of secondary lamella and increased the diameters of the gill filaments and secondary lamellae. Moreover, the presence of TiO2 NPs increased the CuO NPs effects on the histopathological anomalies of intestine tissue and the synergistic effect of TiO2 NPs and CuO mixture leads to an increase in the severity of histopathological lesions such as degeneration, swelling of goblet cells, and necrosis - erosion in the intestine tissue. In conclusion, the presence of TiO2 NPs increased the toxicity of CuO NPs. 相似文献
95.
The use of buyback for the development of oil and gas fields is an established mechanism in Iran. Current legislation authorizes the National Iranian Oil Company (NIOC) to use buyback for both exploration and development. The buyback scheme can be defined as a risk service contract, under which the contractor is paid back by being allocated a portion of oil/gas produced as a result of providing services. Buyback is based upon a defined scope of work, a capital cost ceiling, a fixed remuneration fee and a defined cost recovery period. When buyback is used for both exploration and development, the specifications of the field to be developed are unknown at the time of contracting and therefore agreement on the scope of work, duration of development operations, ceiling for capital costs, fixed remuneration fee, and duration of cost recovery need to be deferred to the time when a commercial field is discovered. This article first outlines the introduction of buyback for development of Iran's oil and gas fields. It then examines the main features of the mechanism. Third, the use of buyback for both exploration and development is explored and related challenges discussed. Finally, the article reviews the new buyback model proposed by NIOC to address these challenges. 相似文献
96.
Ali Mohammad Latifi Seyed Mohammad Nabavi Morteza Mirzaei Mahmood Tavalaei Hossein Ghafurian Claire Hellio 《毒物与环境化学》2013,95(9):1670-1677
Cesium and mercury are two mono-valent elements which can be found in toxic industrial, medical, and nuclear wastes. Their presence in the environment has deleterious effects on the ecosystem, living organisms including humans. Due to the chemical nature of these metals, bioremediation by conventional methods is more difficult to achieve compared to other metals. In this study, we used three biosorbents (oak powder, gall nut, and bacterial exopolymer) for the bioremediation of Hg and Cs. Bio-polymer was produced in the GMS mineral broth. Synthetic wastes of Hg(NO3)2 and isotope Cs-133 as the single-metal solutions were used. The biorefining process was carried out in glass columns, made of Pyrex, with dimensions 20?×?7/2?cm2 with a V-shaped bottom. The samples were analyzed using atomic absorption. The experimental results showed that eliminated metal percent by oak powder, gall nut, and bacterial exopolymer were, respectively, of 94.8%, 96%, and 13.8% for Hg and 7.8%, 4.4%, and 69.4% for Cs. The tests revealed that Ca++, when used as flocculant, played a key role in both biosorption and bio-precipitation rates. Consequently, it was concluded that the investigated biosorbents could be use as an integrated biosorption system for the refinement of mixed wastes. 相似文献
97.
Protective effects of quercetin against sodium fluoride-induced oxidative stress in rat erythrocytes
Seyed Fazel Nabavi Shahram Eslami Akbar Hajizadeh Moghaddam Naser Jafari Mohammad Ali Ebrahimzadeh 《毒物与环境化学》2013,95(8):1666-1675
Protective effects of quercetin against oxidative stress induced by sodium fluoride intoxication in rat erythrocytes were evaluated. Rats were divided into five groups consisting of 10 in each for this experiment. The animals of group I received water and standard diet to serve as control group, the animals of groups II and III were treated with quercetin (10 and 20?mg?kg?1 body weight), administrated intraperitoneally for 7 days followed by sodium fluoride (600?ppm) in drinking water for the next 7 days. The animals of group IV were treated with vitamin C (10?mg?kg?1) intraperitoneally for 7 days followed by sodium fluoride treatment for next 7 days serving as positive control group. The animals of group V were treated only with sodium fluoride (600?ppm) for the same time and were used as control group. Blood sample were collected via retro-orbital puncture. The antioxidant enzymes, superoxide dismutase, and catalase, as well as the levels of reduced glutathione and lipid peroxidation end products were measured in erythrocytes. There was a significant increase in lipid peroxidation along with a decrease in superoxide dismutase activity in the erythrocytes of sodium fluoride-treated animals. Quercetin treatment prior to fluoride administration normalized the levels of all parameters measured in the rat erythrocytes. 相似文献
98.
Abdolinejhad Fatemeh Khayati Gholam Reza Raiszadeh Ramin Yaghoobi Nahid Sadat Khorasani Seyed Mohammad Javad 《Journal of Material Cycles and Waste Management》2021,23(5):1855-1872
Journal of Material Cycles and Waste Management - In this study, a hybrid of support vector regression and a modified tunicate swarm algorithm (SVR-MTSA) strategy is developed to optimize the... 相似文献
99.
Yousef Sakieh Abdolrassoul Salmanmahiny Seyed Hamed Mirkarimi 《Environmental monitoring and assessment》2017,189(2):91
This study attempts to develop a non-path-dependent model for environmental risk management and polycentric urban land-use planning in Gorgan Township area, Iran. Applying three suitability layers of environmental risk (soil erosion, flood risk, fire risk, and land susceptibility), urbanization potential, and integrated surface (environmental risk plus urbanization potential layers), a non-path-dependent Cellular Automata-Markov Chain (CA-MC) model was configured to execute three scenarios of polycentric urban growth allocation. Specifically, the modeling approach improved the traditional functionality of the CA-MC model from a prediction algorithm into an innovative land allocation tool. Besides, due to its flexibility, the non-path-dependent model was able to explicitly include different characteristics of the landscape structure ranging from physical land attributes to landscape functions and processes (natural hazards). Accordingly, three polycentric urban growth allocation efforts were undertaken and compared in terms of connectivity and compactness of the resultant patterns and consumption of other land resources. Based on results, the polycentric allocation procedure based on integrated suitability layer produced a more manageable pattern of urban landscape, while the growth option based on environmental risk layer was more successful for protecting farmlands against excessive urbanization. This study suggests that polycentric urban land-use planning under the strategy of rural land development programs is an available option for designing an urban landscape with lower exposure to natural hazards and more economic benefits to rural residents. Finally, the non-path-dependent modeling is a recommended approach, when highly flexible and interactive decision-support systems as well as trend-breaking scenarios are desired. 相似文献
100.
Nemati Tayebeh Sarkheil Mehrdad Johari Seyed Ali 《Environmental science and pollution research international》2019,26(10):9610-9618
Environmental Science and Pollution Research - We investigated the trophic transfer potential of CuO-NPs from Artemia salina to Amatitlania nigrofasciata. The Cu uptake was investigated by exposure... 相似文献