The current research was conducted by examining the positive and negative effects of virtual spaces and new technologies on the mental health.and lifestyle of students in the second year of elementary school. The statistical population included the students of the second year of elementary school, about 500 people who were studying in the academic year of 1402-1401 in Tehran province, Roudhen region. The statistical sample was estimated to be 350 people according to the table of Karjesi and Morgan, who were selected by random cluster sampling. To collect the data, the questionnaire of virtual space injuries and new technologies have been used. In this research, after confirming the validity, the reliability of each questionnaire was calculated as 0.80 and 0.82 respectively. Descriptive and inferential statistics were used to analyze the data. At the descriptive level, indicators such as mean, variance, standard deviation, frequency and percentage were used. To test the hypotheses of the research, one-sample t-test, Friedman's analysis was used; and with the help of SPSS 22 software was used. The results indicate that the virtual space causes harm such as generation gap, addiction to virtual space, social isolation, conflict of values, etcachers.

The purpose of the present study is to investigate the lived experiences of student teachers about the use of technology in virtual education. The research method is qualitative and phenomenological. The participants in this study were female students of Farhangian University of Makazi Province, who were selected by the purposive sampling method and with the criteria of setting two semesters of virtual education (N=16). In order to collect data, a semi-structured interview method was used. Data analysis was carried out using the seven-step Claysey method. The obtained results indicated the existence of two general themes of challenges and opportunities of using technology in the virtual education of student teachers. These challenges include the lack of acquiring the necessary competencies in learning courses, organizational problems, curriculum problems, problems caused by the lack of face-to-face communication and the lack of infrastructure. At the same time, the use of technology in virtual education has some opportunities such as removing time and place restrictions, increasing access to content, and developing technology materials for students. According to the results, it is necessary to provide the necessary support to adjust the challenges of virtual education.

A common method for controlling a group of parallel converters in decentralized control strategy structure in an island microgrid, the use is the droop-down characteristics of frequency ω-P and voltage E-Q. However, the problem with using this method is that the reactive power is not properly distributed (in proportion to the capacity of the micronutrients) between the micronutrients, which may lead to overload in the converters. Microgrids may also suffer from dynamic stability problems such as power fluctuations, which can be increased by switching between active and reactive power control. To avoid this problem, the X / R ratio of transmission lines is an important parameter that should be carefully considered in the design of micronutrient controllers. By linearizing and simplifying conditions, the control system conversion function model becomes a single input-single output system, which is efficient enough to show the relationship between control parameters such as slope of droop characteristics and derivative sentences, virtual impedance, and voltage controllers. Using this model, stability conditions for different parameters are analyzed. Also, to improve power distribution stability, common droop strategies are modified by adjusting the slope as well as adding nonlinear sentence sections. This approach reduces the coupling between active and reactive power control and reduces the dependence of power distribution on grid parameters such as the X / R ratio. To evaluate the reliability of the proposed model, the simulation results in a sample island microgrid in MATLAB software are presented.

Background & Aim: With increase of living in towns, level of stress will also increase. The aim of this research was to investigate the relationship between green space and mental health.Methods: This cross-relational study was carried out in Tehran in 2011. The sample consisted of two groups of 30 men. One group was resident in green space but the second group was resident in apartments for a period of at least ten years. Also, they were matched for age, educational status, and other criteria considered in this research. We studied mental health.by using SCL-90-R questionnaire. For data analysis, one-way ANOVA was used.Results: The results indicated that there is a significant difference at P≤0.05 between green space and apartment residents in paranoia and neuroticism. But there was no significant difference between two groups in other mental health.components.Conclusion: Living in green environments for a long period promotes mental health. So, results of this study highlighted the importance of living in green environment for improving of mental health.components.