فهرست مطالب m. yahyaee

All of the food products are required to be packaged due to hygienic regard, storage, suitable transportation and preservation of quality and vacuum packaging is one of the prevention methods of spoilage. Hence in this study, some of the quality factores changes of Rutilus frissi kutum fillets storaged in vacuum and air packages were examined during 18 days in ice alike total volatile base-nitrogen (TVB-N), pH, water holding capacity (WHC), thiobarbituric acid reactive substances (TBARS), sensory characteristics and psychrophilic bacterial level. pH of the air packaged samples, rised with increasing psychrophilic bacterial load. Results of microbiological examination, indicated changes in bacterial of Rutilus frissi kutum fillets, has direct relation with sensory quality of packaged fillets in both vacuum and air packs, and shelf life and quality of vacuum packaged fillets was better as compared to air packaging, as cause fillets shelf life increase, 3 days more than air packaged fillets and effectively, controlled volatile bases-nitrogen level but alone was not able to controled lipid oxidation during ice storage. Therefore vacuum packaging cause shelf life time increase and better preservation of sensory, chemical and microbiological qualities of Rutilus frissi kutum fillets in ice.

Considering the purpose of Regulation 2800, which is to ensure the safety of life at risk level 1, as well as the progress made in the design method based on the performance and development of new design regulations, in this study, asymmetric steel structures in one In order to have a coaxial brace that is designed according to the 2800 standard of the third edition and the tenth issue of the national regulations, from the perspective of design, based on the performance and criteria of the Iran Improvement Instruction, Do or not. For this purpose, 12 steel buildings with coaxial brace system in groups of 5, 8, 11 and 14 floors are analyzed and studied by leaving the centers of difficulty compared to the center of mass 0, 10 and 20%, which is due to the displacement of braces in one direction. At the stage of performance appraisal, the results of static and dynamic nonlinear analysis of buildings, including relative displacement of floors, determination of structural performance point, paste deformations of compressive and tensile braces, and ratio of force to column capacity with acceptance, comparison and level criteria. The performance of buildings and their components has been determined. The results show that regular and irregular structures of 11 and 14 floors provide the level of life safety performance at risk level 1. This is almost true of 8-story structures, but in 5-story structures, especially in the symmetrical direction, weaknesses have been observed that need to be addressed to ensure the level of safety of the lifeguard.