فهرست مطالب خانم رحیمی

The reason for this study was the lack of a coherent work on the role of quantitative characteristics of hydrology and topography in determining the spatial distribution pattern of nomad camps in Iran. In this investigation, Kermanshah Province, in west of Iran, was studied. Quantitative hydrology and Topography indices of the province including Heterogeneity Index (TRI), Topographic Wetness Index (TWI), Altitude, slope, slope direction, stream distance, ridge distance, spring distance, formation type, Topographic Position Index (TPI), Surface Relief Ratio (SRR), and Compound Topographic Index (CTI) were calculated. To determine the results, Pearson correlation and linear regression (for parametric data) and LOWESS regression (for non-parametric data) were used between hydrology and topography data and the camps’ area. Then, the type of spatial distribution pattern and spatial pattern type radius of the camps were determined for each one of the above-mentioned factors using Moran’s Autocorrelation Index and Ripleys’ K Function, respectively. There was a significant relationship between the TPI index (the steep slope landform) and the camps’ area. In sum, the first priority in determining the regular pattern of nomads in the Kermanshah Province considers two heterogeneity and slope indices, and the second priority is among the rest of hydrology and topography indices. The nomads’ almost identical choices in selecting location of their camps are dependent on access to non-jagged lands, flat lands, the places with more than 600 m distance from the ridges and less than 500 m from the streams and 2 km distance from the springs, special ranges of TWI, CTI and SRR indices, the altitude range of 1,400 to 2,000 m above sea level, and establishment in the Landform 3 range of the TPI index and limestone formation.

AbstractA previous study on agricultural drains in Khuzestan province of Iran has indicated that carbonate calcium is the main component of the deposited salts in drainage envelops. To investigate the process of precipitation of carbonate calcium under different conditions including chemical, bio-chemical, aerobic and an-aerobic, a through laboratory investigation on geotextile drain envelop was conducted. The results of the studies showed that activity of the micro-organisms in aerobic conditions causes an increase in the bicarbonate content and consequently, increase in the pH of the medium. Any increase in pH would intensify the precipitation of carbonate calcium. The results also indicated that due to the activity of micro-organisms, more than 90% of existing calcium would be precipitated. While in a chemical environment, only 30% of existing calcium would precipitate. Thus, in a biochemical environment, micro-organisms would cause more calcium to be deposited. The results also indicated that the activity of the bacteria would cause formation of bio-films which in turn would provide a more suitable environment for precipitation of salts. By intensifying deposition of salts, there is higher potential for clogging of the drainage envelops including geotextile filters.

Uranium is a radioactive heavy metal. Development of nuclear industries and application of phosphate fertilizers contain uranium impurity resulted in soil contamination with uranium. A Pot experiment had been conducted under controlled condition. The experiment carried out in completely randomized design with two factors, including two plants (soybean and sunflower) and six levels of uranium (0, 50,100,250,500 and 1000 mg/kg). Plants harvested after 40 days of experiment and before the generative stages. Soil samples were extracted by DTPA and AAAcEDTA. Uranium concentration in plant tissue increased by increasing the uranium in soil. The ratio of uranium in root:shoot was between 20-100 in sunflower and soy bean. Extraction efficiency of DTPA and AAAcEDTA increased by increasing of uranium in soil. The results of the experiment showed that AAAcEDTA extracts more uranium in all applied uranium concentrations. Both extractants had a good correlation with uranium in plants; however, extraction efficiency of AAAcEDTA was well correlated by uranium concentration in plant tissues. The results of the experiment suggest that AAAcEDTA is suitable extractant for uranium as phytoavailability indicator.

The production of nanopowders is one the most noticeable applications of induction plasma. An aim of the work is to extend the thermal plasma technique to the synthesis of nanosize nitride based composite powders and to determine an influence of process parameters on characteristics of produced powders. The nanosize nitride –based composites are prepared by evaporation of coarse commercially available powders of chemical elements such as Mo, Cr, Ti, Zr and subsequent condensation of products into a inductively coupled nitrogen plasma(ICP(.