درخت حوزه‌های تخصصی

A sensitivity analysis of the flood safety of Solaimantangeh dam using a regional climate change simulation is presented. Based on the output of the CCSM (Community Climate Change System Model) general circulation model, the NIRCM (North of Iran Regional Climate Model) computes regional scale output with 50 km spatial resolution and 21 vertical layers. Using the SRES (Special Report Emission Scenario) “B1” Climate Change Scenario when applied to the Tajan river basin, where Solaimantangeh dam is located, NIRCM reduces significantly the bias in Annual Maximum Event total Precipitation (AMEP) & Annual Maximum Daily Precipitation (AMDP) that CCSM shows. The stream flow change scenario is then simulated using SSARR (Stream flow Synthesis and Reservoir Regulation) model. A rainfall-runoff model was implemented using precipitation and temperature projected by CCSM and NIRCM. The model demonstrated that average Stream flow would increases 38.7% and the variability would increases 14.3%. This remarkable increase in projected annual maximum flow for the next 20 years (2004-2023) should be a significant negative signal to water resources managers. The results indicate that the number of floods remains almost the same, but that the magnitude of a single flood event and the recovery from it become worse.

The present study aims to present an analytical review of the relationship between development-driven education and environmental improvement. Previous research in this field has often examined the effect of environmental pollution on the human development index in general. However, this study uniquely focuses on a separate review of human development indicators on the environment and education. Thus, this study applied an econometric method using Eviews13 software during the years 1990-2023. The analytical review of the effect of development-driven education on environmental improvement, with an emphasis on the human development index, was conducted among selected countries of the Middle East (United Arab Emirates, Bahrain, Egypt, Iran, Iraq, Jordan, Yemen, Kuwait, Lebanon, Libya, Oman, Qatar, Turkey, Syria, Cyprus, and Saudi Arabia) and Iran. The dependent variable in this paper was CO2 emission, and the independent variables included education, health, standard of living (a measure to evaluate the human development index), fossil fuel consumption, and the growth rate of the urban population. The results of the study in the Middle Eastern countries indicate that the measurement dimensions of the human development index have a negative and significant effect on environmental pollution. Higher human development is beneficial for the environment and mitigates CO2 emissions and other pollutants. Additionally, this protects the environment by lowering pressure on natural resources. The variables of urbanization rate and fossil fuel consumption have a positive effect on the level of air pollution. In addition, the results of the study in Iran demonstrate that fossil fuel consumption and urbanization are factors that directly influence the country’s air pollution, and the measurement dimensions of the human development index. No significant relationship was found regarding education (average years of education for adults), but a negative and significant effect was shown on environmental pollution.

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 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.