Showing 6 results for Kamyabi
Volume 8, Issue 3 (Autumn 2018)
Abstract
During the energy crisis and the world’s attention to optimal energy consumption, especially in buildings, the walls of the buildings became one of the most important parts of the design process. In the first step, air locking and isolation of the walls were important in order to prevent the loss of energy. In the next steps, the need to get proper solar radiation in cold areas and the existence of a tool to prevent the entry of solar radiation in hot areas was raised. The aim of this paper is to investigate the effect of the shading tool location and the optimal combination of glass layers in double skin facade in the warm and humid climate of Iran. The methodology for achieving this goal is to use computer simulations (Fluent software). In this study, different configurations of double skin facade have been investigated. During these surveys, the structure has been considered optimally in the Kish Climate Zone. Three different areas were investigated for the establishment of shaders; the findings of this study are presented as temperature and air flow diagrams and contours. The results of this research show that the most suitable place for the establishment of the shadow tool is the interior and back of the double skin façade. It was also found that the proper type of double skin facade, in order to prevent the optimum from increasing the internal temperature, includes a glass layer in the outer shell and a window with a double-glazed glass in the inner shell. In this paper, the “simulation and modeling research” method has been used. In this paper, the “simulation and modeling research” method has been used. In the software simulation and numerical analysis sections, the type of quantitative research is “analytic” research method and results are obtained based on “induction”.
Volume 9, Issue 1 (Winter 2018)
Abstract
Aims: The aim of the present study was to isolate yeasts with the high ability of decolorization to use as biosorption in removing azo dyes.
Materials and Methods: In this experimental study, an enrichment method was used to isolate dye absorbent yeast in a salt medium. The dye absorption was performed with comparing wet and dried biomass. Decolorization level was evaluated in different concentrations of dye and salt. By molecular method, the best strain was identified and its ability to absorb various dyes as well as mono-, di-, and tri-azo dyes were investigated. Statistical tests including one way ANOVA and Tukey as well as SPSS 19 software were used.
Findings: Among 17 yeast isolates, ADH17 was selected as the most capable isolate. This isolate was 100% similar to Sarocladium sp. Dried biomass could adsorb the dye 4 times more than the wet biomass. The remained dye increased when initial dye concentration rose, but different concentrations of sodium chloride had no significant effect in biosorption. This strain could adsorb a broad range of azo dyes, including mono-, di-, and tri- azo and acidic, basic, and reactive dyes as well. The highest biosorption was 97.43% for reactive red and the lowest biosorption was 87.96% for reactive yellow.
Conclusion: The ADH17 is the most capable isolate and it is 100% similar to Sarocladium sp. This strain adsorbs a broad range of azo dyes, including mono-, di-, and tri- azo and acidic, basic, and reactive dyes as well. Sarocladium sp has a high ability to absorb various azo dyes.
Volume 10, Issue 2 (Summer 2020)
Abstract
Aims: After the attention of the global associations to optimal using of energy, exterior walls of the buildings became one of the most important parts of the designing process. The present study aims to investigate the effect of airflow type and also the optimum spacing between two walls in this façade in the warm and humid climate of Iran (Kish Island).
Methods: In order to achieve this goal, various configurations of double-skin facades have been investigated using computer simulations (Fluent software 19.2). Two types of air evacuation of airflow and external air layer were investigated. Each of these two flows was simulated with three different distances of 1000, 1500, and 2000mm. In the present study, “the
simulation and modeling research method” has been used. In the software simulation and numerical analysis sections, the type of research is “quantitative” and the research method is “analytical”, and the results are obtained based on “induction”.
Findings: The results show that during the peak periods of heat and humidity, when the outside air is not in a comfort state, the type of air evacuation causes high temperature and humidity inside the offices, and
makes trouble for the thermal comfort of the residents and users.
Conclusion: In warm days and months, it is necessary to use an external air layer. It was also found that in the case of using air evacuation, the optimum depth of air cavity is 2000mm and in the case of external air, curtain layer is 1000mm.
Volume 11, Issue 2 (Vol. 11, No. 2 (Tome 56), (Articles in Persian) 2020)
Abstract
integrative and instrumental motivation as well as Ideal self and Ought-to self on the motivation and success of language learners, the present study has investigated these issues among the learners in Persian language. For this purpose, 20 Korean and Chinese students (10 Chinese and 10 Korean students) were selected from the Persian language teaching center of Ferdowsi University of Mashhad. Thus, the statistical sample of the study consisted of 20 Persian-Chinese students and Korean men and women (8 men and 12 women) who were in the age group of 18 to 30 years and in the academic year 2016-2017.
It is also worth mentioning that these Persian students have reached an advanced stage in this center, from the introductory course of Persian language. The Farsi students responded to a 36-item questionnaire based on the Dornyei Motivational Questionnaire (2010). Finally, the data were analyzed using SPSS software. six hypotheses were proposed and we used statistical tests to examine the hypotheses. First, the normality of the research variables was examined and the results showed that these variables have a normal distribution. Therefore, as mentioned, in the next step, we examined the research hypotheses. The results of the study showed that there is a significant difference between Ought-to selves of Korean learners and Chinese or Japanese tutors. However, there is no meaningful difference between Ought-to selves of Japanese and Chinese learners. There was a significant difference between Korean, Chinese and Japanese Ideal selves. In addition, there was no significant difference between the Chinese, Korean, and Japanese learners’ promotional instrumental motivations. While there was a significant difference between preventive instrumental motivation of Japanese learners and Chinese or Korean ones. And there was no significant difference between Chinese and Korean. The results of the research suggest that there is a significant difference between integrative motivation of the Chinese, Korean and Japanese learners. There was no meaningful relationship between integrative motivation of Chinese, Korean and Japanese students and their Ideal selves. There was a significant negative correlation between ought-to self and preventive instrumental motivating of Korean students, while there was no significant relationship between these two variables in Japanese and Chinese students.
In addition, a comparison of the meanings of all four motivational factors in these two groups of Persian-learners showed that, in general, in these two groups of Persian-learners, the Preventing Instrumental motivation was with the highest average, and the Ought-to self motivation has the lowest average. Also, the comparison between the motivational factors of Ideal self and Ought-to self indicates that in these two groups of Persian-learners, the Ideal self factor is stronger than Ought-to self. Comparison between the motivational factors of integration and instrumentation also showed that the Preventing motivational factor is stronger than the integrative factor and the integrative factor is stronger than the promotional instrumental factor.
Finally, it should be noted that the present study focuses only on Chinese and Korean Persian learners; for this reason, it is suggested that in future studies, Persian learners of other languages be examined. In addition, it is suggested that other motivational factors related to second language learning regarding non-Iranian learners of Persian, be examined separately and compared with each other. In this case, how to teach and use educational resources can be planned according to the type of related motivation.
Volume 14, Issue 1 (March & April 2023 (Articles in English & French) 2023)
Abstract
Many students, both at tertiary and secondary level, consider writing for academic purposes as a challenging task. It is of prime importance that students have sufficient content knowledge and basic understanding of different writing strategies to write coherent and cohesive texts. This study unveils the impact of writing strategy instruction on writing strategy use and performance of 40 undergraduates enrolled in an Academic and Professional Writing course. The design of the current study was experimental and data were collected using a questionnaire and students’ essays. The results of the t-test present that writing strategies training could be imparted to the students to improve their overall writing. The treatment group showed a significant improvement in their writing performance and writing strategy use after receiving strategy instructions. The study recommends explicit writing strategy instruction be incorporated into English writing courses and learners be encouraged to use them in their writing tasks.
Mojtaba Dialame, Ata Kamyabi, Ali Moradi,
Volume 15, Issue 10 (1-2016)
Abstract
In this research the effect of the screw angle and the depth of the channel were examined on the flow rate of an incompressible Newtonian isothermal and a non-Newtonian fluid flow in a single screw extruder. In the presented study the pressure drop has not been considered and only drag force was considered. For this purpose, the channel of extruder was assumed a cubic and spiral channel. Accordingly the Newtonian flow was simulated by Fluent foftware package and the results were compared with analytical solution in several angles. Then one step from the shallow spiral channel was examined and the results were compared with analytical solution in different angles and also at low Reynolds numbers. Hence, the obtained results reveal the range of validity for the analytical solution at different Reynolds numbers. As the results show, at low Reynolds numbers, up to 10, and the ratio of channel depth to diameter, less than 0.2, numerical and analytical results are the same for Newtonian fluids. Identically in this range the analytical solution can be used for screw design, calculation of the maximum flow rate, the evaluation of the optimum angle, etc. The results of the study of non-Newtonian fluid showed that the flow rate at low screw angles for non-Newtonian fluids were higher than the Newtonian cases and at high angles, were smaller.
