درخت حوزه‌های تخصصی

Urban heat island is a phenomenon caused by increased urban activities and transformations in the natural environment. Increased urban population and increase in the height of buildings, particularly in metropolitan areas, have led to vast changes in the urban geometry, amount of released heat, pollution rate, and meteorological parameters. All these factors contribute to the occurrence of heat island phenomenon in urban areas. Sky View Factor (SVF) is one of the main factors related to pollution, temperature variations, heat island, and other environmental parameters. Housing density policies stipulated in Tehran's detailed plan would possibly have several impacts on the sky view factor. The SVF axis of the Envi-met software uses various parameters such as topography, wind velocity, and urban morphology to simulate and measure sky view factor. This study aims to evaluate impacts of the future high-rise developments, in the Narmak neighborhood of Tehran through modeling future changes in the sky view factor. For this purpose, data related to Haft Hoz square located in the Narmak neighborhood was collected, simulated and analyzed using SVF. Results indicate that in the business as usual scenario, the factor’s value would be in a range between 0.19 and 0.77; whereas, by implementing the scenario proposed in the detailed plan the factor will decrease to fall in a range between 0.08 and 0.69. This reduction in the intensity will possibly increase heat island impacts in the study area. This study emphasizes the necessity of taking compensatory policy measures and incorporating environmental considerations in urban development plans.

Purpose : The aim of present research was identifying the effective components on managing the challenges of thesis writing based on the lived experiences of PhD students in Islamic Azad University. Methodology : This study in terms of purpose was applied and in terms of implementation method was phenomenological from type of qualitative. The research population was students and graduates of the PhD period of humanities fields at the Islamic Azad University in 2020-21 academic years. The research sample according to the principle of theoretical saturation was determined 12 people which were selected by purposive sampling method. Data were collected by semi-structured interviews whose validity by 15 professors was obtained by the relative content validity coefficient method 0.866 and its reliability by the Holsti coefficient method was obtained 0.865. Finally, the data were analyzed by open, axial and selective coding method in MAXQDA-18 software. Findings : The results showed that for managing the challenges of thesis writing based on the lived experiences of PhD students were identified 67 indicators in 13 sub-components and 3 main components. The main components were included administrative-organizational solutions (with three sub-components of maximum use of virtual systems, modification of the thesis doing process and financial assistance), solutions (with three sub-components of increase study, proper planning and strengthening skills) and educational strategies Conclusion : The results of this study have practical implications for graduate officials and planners, and they can use the identified components to properly manage the challenges of thesis writing and improve them in the higher education system.