درخت حوزه‌های تخصصی

Hail phenomenon is one of the hazardous weather phenomena that can make the highest amount of damage to farms, gardens, cars, rooftops, etc. in a very short time (a few minutes), depending on the diameter of the particles. One of the best ways to study this devastating climatic phenomenon is the use of atmospheric instability indices. The indices which are calculated with the help of radiosonde data give a fairly comprehensive vision regarding the occurrence of such phenomenon. In this study, the incidence of moderate to severe hail is investigated in the period of 1990-2010. First, the atmospheric codes related to hail phenomena were applied to extract the data, then radiosonde data in intended time were received and applying the RAOB software, the physical status of atmosphere was studied. In the studied period, two hail examples were reported on November 27, 2008 and December 5, 2008. In the first instance of hail that occurred on November 27, 2008, the status of some indicators was calculated and it was found that LCL was at an altitude of 284 meters, CCL at an altitude of 1582 meters, LFC at an altitude of 6230 meters, the ice surface at an altitude of 3278 meters, the LI index was -0.2, the K index was 25.7 ° C, and PWC was 28 mm. In the above mentioned conditions, there was a hail with a diameter of 25.4 mm. In the second instance of hail that occurred on December 5, 2008, the status of some indicators was calculated and the results showed that LCL was at an altitude of 280 meters, CCL at an altitude of 1762 meters, LFC at an altitude of 2271 meters, the ice surface at an altitude of 2771 meters, the LI index was -1.4, the K index was 27.1 ° C, and PWC was 23.6 mm. In the above mentioned conditions, there was a hail with a diameter of 3.6 mm. Given that in many ways, the status of most atmospheric indicators in the two above examples of hail were close to each other, it turns out that in similar circumstances, the greater the distance the ice level gets to the summit of cloud, the greater is the probability of hails larger in diameter. The value of this distance for November 27, 2008 was at approximately 6384 meters and for December 5, 2008, it was at about 5012 meters.

The rights of citizens to provide Social justice, due to emphasis on the basic needs of human beings, known as one of the most fundamental principles in international documents of human rights and civil rights. It's indicators include the right to a fair life, right to health, right to education, right to social security, and right to work and employment, which in human rights documents, particularly in the International Covenant on Economic, Social and Cultural Rights, regarded as the second generation of human rights. Social justice, who has been noted specifically in the first, third and fourth chapters of Constitution of the Islamic Republic of Iran, are the same components that have been identified in international documents of human rights. These indicators will realize when all citizens have equal opportunity to take advantage of it. The government's obligation to support these rights is positive, and an obligation to urgent results and in some indicators the obligation of result, is increasing.

In last decades, the skillful planning of land resources has become a major issue for rural development. The development of cultivated areas becomes gradually impossible due to ever increasing population growth and urban development. Fuzzy logic is preferred to Boolean logic for land evaluation, because fuzzy techniques lead to estimate for land use suitability on a continuous scale and can therefore, be more informative than the Boolean technique. The objective of this study is to apply fuzzy set methodology in the context of a decision making process known as the Analytic Hierarchy Process (AHP) to land evaluation for irrigated wheat. The results revealed that the results obtained with fuzzy AHP method are in better agreement (R2=0.911) with the observed yield as compared to those obtained with parametric method (R2=0.804). Although, the fuzzy AHP provided more efficient and accurate results than parametric method, the choice of membership functions, width of the transition zones and weight values are determinant to achieve its realistic results in land suitability assessment.

The aim of this study is to investigate the relationship between social capital among employees with their job performance in Tehran's Forensic Medicine Organization. The study population consisted of all the employees of Tehran's Forensic Medicine Organization in 2015 that based on available statistics are 120 employees that because of limited statistical population, sampling has not been done. To collect data, two instruments were used to measure including social capital questionnaire of Nahapiet and Ghoshal (1998), with average reliability coefficient of 93% and job performance questionnaire of Hersey and Goldsmith Achiu model with average reliability coefficient of 88%. Descriptive statistics were used to describe the data and to analyze and evaluate the research hypotheses; test of inferential statistics including univariate regression analysis was used. While confirming the research hypotheses, results showed: Structural, cognitive and communicative dimensions of social capital of employees have an increasing and positive impact on their job performance and this effect is statistically significant.