فهرست مطالب sajad akbari

One of the most important applications of data envelopment analysis tech-nique is measuring the efficiency of bank branches. Performance measure-ment in the banking industry is important for several groups, including bank managers, customers, investors, and shareholders. The purpose of this study is to examine and design a mixed structure to measure the efficiency of branches of Iranian banks according to their policies. In order to obtain the efficiency of the structure divisions proposed in this study, a slack-based NDEA model was selected to solve its mathematical model. The study sam-ple consists of 31 branches of a large commercial bank in Iran. The ad-vantage of this research to previous studies is that the result will be more realistic considering the inputs and outputs consistent with Iran's banking conditions.

Different factors influence on the properties of wood composite panels. Evaluating all of these factors not only increases waste of time and energy but also decreases accuracy in estimation of influence value of selected factors in manufacturing panels in order to obtain optimum point of different properties of wood composite panels. Hence, application of a new statistical method is necessary for determination of model estimating production´s optimum point. This study was aimed to evaluate the artificial neural networks performance to model the physical properties of the particleboard made of canola stalks particles. The physical properties of the particleboard were modeled and estimated using different weight ratios of melamine formaldehyde to urea formaldehyde, canola stalks to poplar particles and mat moisture content through MLP, RBFN and ANFIS artificial neural networks. The results showed that MLP neural network has better performance than RBFN and ANFIS neural networks to estimate the physical properties of the particleboard. The results also showed that the artificial intelligence models have a proper precision and ability to predict the particleboard's physical properties. The results of the sensitivity analysis also showed that for estimating and , the most important parameter was mat moisture content with a positive effect on the modeling, and melamine formaldehyde to urea formaldehyde ratio was also the most effective parameter for estimating and .

Q fever is a zoonotic disease caused by an obligate gram-negative intracellular pathogen called Coxiella burnetii. The aim of this study was to determine the seroprevalence of anti-C. burnetii antibodies in bulk tank milk (BTM) samples of dairy cattle in west and northwest of Iran.

Overall, 71 BTM samples (covering nearly 700 dairy cattle) were collected in autumn 2013. A commercial Q fever antibody ELISA Test Kit (Liebefeld-Bern, Switzerland) was used to identify the presence of antibodies against inactivated phase 1 and phase 2 C. burnetii antigens.

The results of ELISA test showed that 17 BTM samples (23.9%) were positive for the presence of anti-C. burnetii antibodies.

This study is the first to evaluate presence of anti-C. burnetii antibodies in BTM samples from dairy cattle herds in west and northwest of Iran. The high prevalence of this pathogen highlights the need for pasteurization of raw milk and raising awareness in consumers of dairy products in these regions.

In this study, the effect of particle size used in surface layers and shelling ratio on the mechanical properties of there-layered particleboard manufactured from treated canola (Brassica napus) particle was investigated. The shelling ratio at three levels (2.82:16mm, 5.33:16mm and 8.6:16mm), particle size used on surface layers at two levels (>1.25 and 1.25 mm in surface layers of panels caused an increase in MOR, MOE, IB. Besides, it was determined that increment in particle size on surface layers and using water – leached treatment improved the mechanical properties of panels. According to the results, with the usage of canola stalks particles treated with hot-water used in core layer, applying particles with the dimension of >1.25mm on surface layers of three-layered panels with shelling ratio of 2.82:16mm and 5.33:16mm, it can be obtained the desirable MOR and MOE.

This study was carried out in order to evaluate the effect of nano SiO2 solation on physical, mechanical and morphological properties of popular (Populus deltoids). Test samples for physical and mechanical properties by using Immersion method in nano SiO2 solation in laboratory temperature were saturated. Then, physical tests including basic density, volumetric shrinkage and swelling and water absorption according to ASTM standard and mechanical properties including impact strength, compression strength parallel to the grain, bending strength, modulus of elasticity and hardness were done on the treated and untreated samples respectively according to ISO, ASTM, B.S and DIN. The result showed that Treatment of the Populus deltoids with nano SiO2 increased the basic density, water absorption, hardness, bending strength, modulus of elasticity and compression strength parallel to the grain. So that volumetric shrinkage and swelling and impact strength of treated samples was less than untreated samples. The results of statistical analyzes showed that between treated samples and without treatment for bending resistance, modulus of elasticity, hardness, impact strength, density and shrinkage and swelling tests there are significant differences at 95% confidence level but for compression strength parallel to the grain and water absorption tests there is not a significant difference.

In this study the possibility of using canola stalks mixed with poplar wood in the manufacture of particleboard was investigated. Weight ratio of canola particle to poplar particles at five levels (98, 93/75, 87/50, 81/25, 77%), the weight ratio of the urea-formaldehyde/melamine formaldehyde resin as a adhesive at five levels (23, 18/75, 12/50, 6/25, 2%) and moisture content of matt at five levels (10, 12, 15, 18, 20%) were selected as production variables. Mechanical properties of boards consist of MOR, MOE and IB was tested. According to the results, with increasing the canola stalks/poplar particle ratio MOR and MOE of the boards decreased, but all of the values obtained from treatments were higher than standard. Interaction effect analysis of variables showed that the increasing the ratio of melamine formaldehyde/urea formaldehyde resin decreased the bending strength, while the increasing the moisture of mat increased MOR and MOE. IB values of all treatments are lower than the standard. According to the results of response surface methodology (RSM) and interaction effect between studied variables on the mechanical properties of the panels, the best situation for producing the panels was selected as: weight ratio of 84/32 for canola/poplar particle, ratio of 6/25 for UF/MF resin and moisture content of 12% for mattress.