فهرست مطالب seyed mehdi abtahi

The Persistent development of quick and accessible readout tools promises to remove one of the barriers to the adoption of gel dosimetry as an applicable method in treatment clinics. Research and development in the imaging of polymer gel dosimeters continues with a focus on imaging in three dimensions. Each technique comes with its own set of advantages and challenges. In gel dosimeter research, efforts have been made to identify and develop alternative imaging methods for polymer gel dosimeters. Gel dosimeters can obtain reliable and accurate three-dimensional dose distributions from the correlation of different polymerization stages caused by radiation. The irradiated samples are examined using magnetic resonance imaging, optical computed tomography, and X-ray computed tomography. This research describes the basic features of imaging devices and the readout of irradiated dose data. Costs, availability, portability, contrast and resolution, high-resolution image reconstruction algorithm, and image reconstruction time of radiation absorption dosimeters for imaging devices are investigated in this research. This review has been done to present the mentioned imaging features and review the research done in this field for the optimal use of different imaging methods.

Soil erosion is one of the main phenomena related to soil degradation that threatens environmental sustainability and soil productivity. It has always been a major environmental challenge worldwide. Soil erosion and its harmful consequences are a serious obstacle to the development and progress of countries and have adverse effects on agricultural production, water quality, and ecosystem health. Soil erosion control intends to promote innovative land management approaches. Soil conservation methods reduce soil erosion, improve soil structure and water uptake, and maintain soil moisture. Therefore, it is necessary to study soil erosion factors and provide management strategies to mitigate it. This study identifies and prioritizes soil erosion factors and strategies to prevent soil erosion in Fars, Iran.

This research is applied in terms of purpose, with a descriptive-survey nature. This study presents a combined approach based on Grey SWARA and Grey ARAS methods to identify soil erosion factors and prioritize methods to prevent soil erosion. After literature review and interviewing an expert panel, the soil erosion factors in Fars were identified and classified into technical, chemical, social, environmental, and climatic. The weight of the criteria was calculated by the Grey SWARA method. Then, the suggested methods and strategies were identified and provided to the panel to evaluate based on the criteria by completing a questionnaire. Then, they were finally prioritized using the Grey ARAS approach. In order to consider the uncertainty and indeterminacy of opinions, grey numbers were used in the calculations.

The results indicated the following as the most important factors affecting soil erosion, respectively: "soil erodibility," "low aggregate stability," "deforestation and ecosystem degradation," "cultivation on slopes and plowing of sloping lands," "loss of vegetation," and "reduced organic matter." The most important preventative measures were prioritized as follows: "ratifying and implementing regulations to preserve soil and natural resources and the developing training and promoting workshops, promoting conservation tillage and smart agriculture, adding organic matter to the soil, mulching the soil with organic or artificial material, and adopting bioengineering methods, such as soil stabilizing bacteria" and "rangeland enclosure and fencing and promotion of industrial livestock.

As unfortunately, in Iran, soil erosion is several times the global average, and a large volume of good soil becomes out of reach per year, it requires serious management measures. More specifically, an extensive management plan should address soil erosion in Fars. It can be expected that findings in this research will help water, soil, and agriculture decision-makers make the most appropriate decisions and solutions to solve soil erosion problems.

The purpose of this study is to design a resource allocation model in educational organizations. In this research, the statistical society was defined in two formats. The research method is a survey and statistically of a type of development. The sampling method was used in the research in the experts section of the census type and in the educational-oriented organizations of the simple cluster type. In this research, to increase the validity of the questionnaire, a questionnaire was prepared, then articles, books and journals were designed and then questioned with a number of professors, and questions were considered. Then, a number of questionnaires were distributed among each section of the statistical society and all ambiguities were identified and resolved and the final questionnaire was distributed. Since the questionnaires are made up of a series of indicators or criteria, their reliability is unnecessary. Delphi analysis method and AHP hierarchical analysis method were used to analyze the data. In Delphi analysis, 23 factors were identified in the form of three dimensions of financial, physical, technological and human resources. Also, the results of the AHP hierarchical analysis showed that financial costs have the highest priority among dimensions. After that, physical and technological resources have been prioritized.

A group of uses of central area of Isfahan, due to incompatibility with its neighbor uses and the area function, has important role on traffic and trip generation of this area. The present essay aimed at the determination of uses affected the rate of trip generation of the downtown(area) of Isfahan and calculation of coefficient of trip attraction for these uses has studied the effective factors on trip generation rate of this area and with calculation of the coefficients of trip attraction of these uses and also their shifts, it has replied to this question that which one of these uses has more effectiveness on generalization and attraction of trip of this area and also what is the effect of their shifting on the traffic of the area. For this purpose, twelve traffic zones forming central core of Isfahan city has been determined as the region under study and the data related to trips attracted for each of them were collected in six-class frame. The coefficients of trip attraction of uses were calculated by dividing the number of daily trips on each uses into area of that use; this coefficient proved that for each square meter of one use, how many daily trips are done .Then, using the standard of transportation engineers of America (ITE) which offers some factors as a suitable suggestion for all uses, the coefficients of trip attraction of uses in available state and recommended state were compared. The results showed that in all uses but medical use, trip attraction is very close to the recommended state and even it is more desirable in some cases .Also the results developed from effect of shifting medical uses to the outside of the area on traffic state were presented.

This paper describes the properties of asphalt samples modified with ground scrap tire rubber and reclaim rubber. In this way، a pull out test was designed to investigate the interfacial shear stress between asphalt (neat and/or modified) and aggregate. The pull out test was carried out through modification of the tensile tester machine. According to the experimental design، the effects of rubber particle content، blending temperature، mixing time and types of aggregate (limestone and/or steel slag) were investigated on the pull-out force. Therefore، the optimized conditions of preparation of rubber-modified asphalt-concrete were obtained. After that to investigate the performance of asphalt rubber concrete، the dynamic shear rheometer (DSR) test was conducted. Therefore، the high temperature performance of asphalt was obtained. Studies and experiments indicate that use of ground rubber to modify binder is desirable from stand point of technical In addition، it is desirable from an environmental point of view.

Many factors and parameters are involved in urban accidents. Some of them are Geographical and environmental factors and some others are accidents descriptive data. In review of environmental factors, ambient lighting condition and deficiency symptoms: and of descriptive data, driver's education, the way of cars clash and type of sketch are the remarkable factors of urban accidents. This study has researched these factors regression using statistical data from the form 114. The results of this study using the chi-square test shows that these factors will have a significant impact on each other