In recent decades, brown trout populations have been declining due to river regulation and its impact on river morphology along Lar River downstream of Lar Dam located near Tehran. Currently, due to water scarcity in the country, intensity of water regulation impacts on aquatic population of streams and specific ecologic values in tributaries of Lar River, it is necessary to present a habitat assessment model to predict ecologic response of the river to natural and man-induced changes by which can be applied to strategic management of the river. Hence, in this research, an analytically applied approach is adopted to assess brown trout population by creating relation among hydrologic, hydraulic, morphologic and ecologic processes. After field work and required measurements, Shields function was applied to derive dimensionless shear stress for minimum environmental flow, bankfull discharge and critical discharge for initiation of sediment transport for Lar, Dalichai and Sefid-Ab rivers. Then, dimensionless shear stress for initiation of the bed sediments was used to investigate effects of discharge variation on frequency and distribution of aquatic life in response to morphologic changes. It was found that when water discharge is in the range of discharge corresponding to environmental flow threshold and critical discharge for sediment motion, it is identified functional discharge for bed occupation while water discharge greater than critical discharge for sediment motion is also considered functional discharge for bed preparation. Results obtained from this research, suggest that water discharge, cross-sectional geometry and bed material size could be effective on ecologic functions and life cycle of brown trout fish and inappropriate river regulation may lead to gradual elimination of that from river ecosystem.

This research is aimed to investigate the effect of crystallization parameters like cooling rate, seeding ratio, a cooling trend, and agitation intensity on the morphological properties of ammonium perchlorate crystals. A solution of AP was prepared by solving industrial grade ammonium perchlorate into the pure water and recrystallization was conducted using a 1. 3 L agitated batch crystallizer. The effects of the selected parameters were analyzed by applying Taguchi’ s method. Resulted crystals were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The results indicate that the cooling rate has the greatest contribution to the roundness of the crystals and by optimization of the parameters, roundness and its standard deviation have been improved by 9. 4% and 79% respectively. Compared to the industrial crystals, the crystallinity of the resulted crystals was also substantially enhanced.

BACKGROUND: The nematodes which belong to Haemonchus genes have high ability to show genetic and morphological changes. They can live with convenient adaptation in different hosts.OBJECTIVES: A Morphologic and Morphometric comparative study on Haemonchus nematodesfrom domestic ruminants in the southeast of Iran and comparison of studied parameters with the results of other researches around the world.METHODS: During an annual period the 100 adultHaemonchus nematodes (50 male and 50 female) were collected from each domestic ruminant (sheep, goat, cattle and camel) from Nehbandan (southern Khorasan), Zabol and Zahedan (Sistan and Balouchestan) in the southeast of Iran. In present study the measured parameters are: Total body length of male and female adult nematodes, gubernaculum length, right and left spicule length, the distance between spicule spine and the spicule posterior end, the distance between anterior cervical spine and the anterior end of nematode, the egg diameters. Also, the anterior sections were observed in order to study the longitudinal cuticular ridges (Synloph). The achieved data from nematodes of each host were compared with others using (One Way Anova and Tukey tests), also such comparison was done with the results of one of the standard sources (Soulsby 1982) using One Sample T Test.RESULTS: The results of present study showed that some of the parameters such as spicule length, distance between right spicule spine and the spicule posterior end, and Synloph pattern in nematodes from sheep and goat are mostly similar to Haemonchus placei. The significant statistical differences in present study results showed high polymorphism inHaemonchus nematodes in the area.CONCLUSIONS: It seems that such high polymorphism in present nematodes, especially from sheep and goat has been created due to mating of native nematodes and foreign species with the source of imported cattle.

This study aimed to determine the relationship between vegetation properties of Cerasus microcarpa C. A. Mey. and physiographic and soil conditions in forests of Kermanshah province. After identifying the main habitats of C. microcarpa habitats, min and max range of altitude were determined. Concerning geographic expositions and terrain condition, 17 circular sample plots of 500 m2 each were established, in which C. microcarpa individuals could be grouped, with at least three of the total 122 shrubs in a plot. Furthermore, 17 soil profiles were dug, in which the parameters including pH, EC, C%, CaCo3 and soil texture were determined. The PC-ORD software was used for Canonical Correspondence Analysis on the data. The results suggested that the geographical aspect plays an important role in selecting land form for C. microcarpa establishment, so that the shrubs are more distributed at the edges and valleys in northern slopes, while they are more presented in foothills and plains in southern slopes. The total height of shrubs in northern slopes and edges was higher than those in both southern slopes and plains. Both trunk and crown length reduce by increasing clay, CaCo3, EC and decreasing slope%. A direct relationship was observed between total height of shrubs and altitude and sand. Finally, the environmental conditions in southern slopes and plains which are accompanied by increasing the acidity and silt, which in turn contribute to increase the crown area and diameter at breast height of C. microcarpa shrubs.

Populus euphratica Oliv. is one of the important poplar species which regenerate mainly through asexual reproduction, for which there is not enough genetic variation within its plant populations. This work investigated several morphological and micro-morphological traits on four half-sib progenies of each eleven parental clones of the species which was grown in a collection at Alborz Research Station, located at Karaj, Iran, as new produced genotypes. Therefore, 44 new clones of progenies of 11 parental clones were studied, based on a nested statistical model for the traits. Results indicated a vast variation between the studied parents and their progenies that may be used to produce new commercial varieties of the species. Average performance of the studied progenies increased on the traits such as leaf length and width, of which leaf area would be increased; resultantly this would improve plant photosynthesis. The higher performances of the progenies for the traits imply a suitable potential for selecting the genotypes with higher performance within the new produced progenies. Petiole length and leaf width showed a significant positive correlation to stomata length as well as significant negative correlation to number of stomata. Regarding the role of stomata on plant photosynthesis, the correlation values may be used for indirect selection of suitable genotypes of the species.

Facilities built in areas affected by earthquake activity, such as tunnels, which have always been an integral part of human life, must withstand both dynamic and static loading. It has led to the need for practical studies on the effects of earthquakes on underground structures and the factors affecting their destruction. For this purpose, in this research, at first different patterns of tunnel’s excavation were investigated and by using Plaxis 2D software and based on Tabas earthquake in Iran, sensitivity analysis on geotechnical parameters of the soil surrounding tunnel such as cohesion, friction angle, unit weight and modulus of elasticity was carried out, and the parameters whose changes have the greatest and least effects on the bending moment changes on the tunnel lining are introduced. The results show that tunnel excavation patterns significantly affect the bending moment, axial forces, displacements, and surface settlement of the tunnel. Often, by dividing tunnel excavation area to small parts, the values of bending moment, axial forces, displacements, and surface settlement of the tunnel decreases in static analysis. Also, outputs of sensitivity analysis on geotechnical parameters of the soil surrounding tunnel showed that modulus of elasticity of the soil surrounding tunnel has the most effect and cohesion changes have the least effect on bending moment induced on tunnel lining..