As investigation of quantity and quality factors and healty condition situation for sturgeon fry in Shahid Marjany and Sade Voshmgir Hatcheries

Survy on some quality and quantity factors on Strugeon fry has been conducted at two ratcheries in cluding Shaiid Marjany and Voshmgear Sad from may to late July for the years 2000 to 2001. Of 64 , 15 and 2 ponds have been randomly collected in 2000 for Voshmgear sad and Shaiid Marjany respectively.In 2001, 17 and 5 out of 65 ponds were collected for the former and latter ones respectively. The items for the quality investigation included : 1- inspection of fry disease 2- inspection of physical and chemical factors for ponds 3- inspection of phytoplankton. Quality investigation was related to count the fry during releasing, growth coefficient and condition factor. No disease was observed for fry in Shaiid Marjany hatcheries Based on 210 and 372 fish examined in 2000 and 2001respectively. In 2000, of 953 fry specimen examined in Voshmgear Sad ,36.1% was infected to Tricodina parasite and 16.4% out of the total 1196 specimen examined in 2001, followed by Jearodactylous parasite.In relation to physical and chemical factors, the average temperature of water was higher than the opitimal one for both hatcheries. Transparency was low wherease NO_3 , NO_2 and aurtophofat was in optimum condition..It was indicated that phytoplanktons belonging to Clorophyta phylum constituted the highest value in terms of biomass , followed by Clorophyta and cyanophyta Ones. The highest abundance was related to pediastrum , cholorella and scenedesmus genouses. It was the same for Shaiid Margany hatchenes. Quality investigations showed that Voshmgear and Shaiid Marjany hatcheries accounted for 836% and 16.4% of the total provience production in 2000. It indicated 59% and 40.36% for the hatcheries respectively in 2001. In 2000, high and low proudction of voshmgear Sad was as 84.4% and 3.8 which was related to Acipenser persicvs borodine , Acipenser guldenstadti brondt respecively. In 2001 , These amounts were as 98% and 0.5% for these species respectively.The highest value of releasing for fish below 3g belonged to to Acipenser persicvs borodine species which was as 76% and 63% in 2000 and 2001 respectively. In 2000 , the hishest and lowest level of proudction at Sahiid Marjany hatcheries was related to Acipenser guldenstadti brondt and Acipenser persicvs borodine species with values of 35.6% and 29.28% respectively. Acipenser persicvs borodine species accounted for 83.5% of the toal fish below 3g, indicating the lowest value in 380 and Acipenser persicus borodine , Huso huso constituted the highest (71%) and lowest (8%) production .The highest level of releasing for fiy (below 39 g) was related to Acipenser persicus borodine species (23.8%)

Nonlinear Dynamic Analysis of RC Shear Walls using Damage Mechanics Approach Considering Bond-Slip Effects

In this research, nonlinear dynamic analysis of concrete shear wall using a new nonlinear model based on damage mechanics approach and considering bond slip effects is presented. Nonlinear behavior of concrete is modeled by a rotational smeared crack model using damage mechanics approach. The proposed model considers major characteristics of the concrete subjected to two and three dimensional loading conditions. These characteristics are pre-softening behavior, softening initiation criteria and fracture energy conservation. The model was used in current research analysis after verification by some available numerical tests. Reinforcements are modeled by a bilinear relationship using two models: Discrete truss steel element and Smeared model. In Discrete model the effects of bond-slide between concrete and rebar is mentioned using the bond-link element model concept. Based on the presented algorithms and methodology, an FEM code is developed in FORTRAN. The validity of the proposed models and numerical algorithms has been checked using the available experimental results. Finally, numerical simulation of CAMUS I and CAMUS III reinforced concrete shear walls is carried out. Comparisons of deduced results confirm the validity of proposed models. The obtained results, both in the expected displacements and crack profiles for the walls, show a good accuracy with respect to the experimental results. Also, using discrete truss element model with respect to the smeared steel model leads to increasing the accuracy of maximum displacement response to 7% in analysis

Records of ants (Hymenoptera: Formicidae) from Northern Iran

<div><p>The results of ant collecting in two hitherto unsampled areas of Iran, the north eastern province of Khorasan Razavi and the north western Zanjan Province are reported. Both areas fall within lacunae of knowledge on previous distribution. Species previously not known from Iran are <i>Aphaenogaster holtzi</i>, <i>Camponotus (Myrmentoma) rebeccae</i>, <i>Cataglyphis albicans</i>, <i>Cataglyphis rockingeri</i>, <i>Lasius himalayanus</i> and <i>Proformica ferreri</i>.</p></div