فهرست مطالب mohamadmehdi rashidi

In the present study, the effect of recycled glass fibers on the behavior and mechanical properties of concrete was investigated. The research was conducted by laboratory study method. Various cubic and cylindrical samples were made in the laboratory. In all mixing designs, the water to cement ratio was 0.35 and the sand to cement ratio was 1. First, a reference sample without fibers and additives was prepared and subjected to various tests. Examination of the samples after the experiment showed that failure occurred in the samples without recycled fibers and brittle glass waste; But failure in samples reinforced with recycled fibers and glass waste is gradual. Under these conditions, in samples made by spray method, the modulus of rupture and displacement of samples to the moment of failure, had much higher values ​​than samples made in the pre-mixed method. As the age of the samples increased from 7 days to 90 days, the modulus of specific rupture of the cement decreased; However, there is no definite trend in changes in the specific rupture modulus of the pozzolanic effect over time. According to the results, it can be seen that over time from 7 to 28 days, the specific compressive strength of cement and also the specific compressive strength of the pozzolanic effect has increased. Over time from 7 to 28 days, the specific compressive strength of cement as well as the specific compressive strength of the pozzolanic effect has increased.

Close relationship of culture with the climate, living environment and lifestyle of residents can be considered a strong, attractive and diverse background for tourism planning. This means the maximum use of cultural capital, which leads to cultural fundamental recreation by considering cultural activities and events as a facilitator and a driving force for urban regeneration. This approach explores the use of existing cultural capabilities to redefine the forgotten city mechanisms, economic prosperity, guiding the integrated urban development, and generally turning threats into development opportunities. The purpose of this study was to explore the potential of the culture-based recreational approach to the success of urban tourism in the Fahadan neighborhood of Yazd. The type of research is applied and its method is descriptive-analytical. To collect information, documentary and field survey methods using questionnaire tool have been used. The statistical population of the study is domestic and foreign tourists in Yazd and Fahadan, whose sample is 268 people. The results of the study, using multivariate regression analysis, showed that among the four components of the basic culture of recreation, namely environmental, formal, functional and semantic, the semantic component has the highest capacity in the neighborhood in order to recreate the base culture and development of tourism and in In contrast, the functional component needs to be strengthened and more planned in line with the objectives of tourism rehabilitation and development. The order of priorities indicates that the neighborhood of Fahdan has a "semantic dimension" and a high mental image for neighborhood visitors according to their ancient history, So that the meaning of the transfer is taken well in the neighborhood. Elements that have been able to replace the user's mental image are Shaykh Fahdan, Qadiyama Mosque, Fahdan Mosque, Ziyari's School (Alexander's Prison). The existing spatial organization of the neighborhood largely matches the image of the tourists. Also, the existence of social partnerships in a public space has prompted volunteered users to enter these spaces voluntarily.

In this paper, a new combined power and refrigeration cycle is proposed, which combines the Rankin power cycle and the Ejector refrigeration cycle. This combined cycle produces both power output and refrigeration output simultaneously. This cycle is driven by the flue gas of gas turbines, industrial waste heats, solar energy and geothermal energy. An exergy analysis is performed to guide the thermodynamic improvement for this cycle and a parametric analysis is conducted to evaluate the effects of the thermodynamic parameters that are significant on the performance of the combined cycle. The results indicate that the biggest exergy loss is due to the irreversibilities. The ejector causes the most effect on exergy loss. It is also shown that the turbine inlet pressure, the turbine back pressure, the condenser temperature and the evaporator temperature have significant effects on the turbine power output and exergy efficiency of the combined cycle.