Showing 127 results for zarei
Volume 0, Issue 0 (in press 2024)
Abstract
Soil stabilization techniques have traditionally relied on cement or lime, yet there remains a significant knowledge gap regarding the mechanical behavior of soil treated with innovative materials. Addressing this gap, this study delves into the mechanical properties of soil stabilized with polyurethane (PU) foam, nano-silica, and basalt fiber. Through rigorous experimentation, unconfined compressive strength (UCS) and direct shear tests were conducted on reconstituted silica and calcareous samples, each treated with various combinations of these additives. A comprehensive examination of parameters such as additive content and curing time was undertaken to elucidate their effects. The results unveiled a noteworthy enhancement in UCS and shear strength parameters (cohesion and friction angle) with the incorporation of PU foam, nano-silica, or their amalgamation with fiber. Particularly striking was the superior performance observed with the combination of PU and basalt fiber, showcasing remarkable improvements in the mechanical behavior of both silica and calcareous sand, especially when considering shorter curing times. The synergistic effects of PU and basalt fiber proved instrumental in fortifying the soil's structural integrity against environmental challenges. Furthermore, it was consistently observed that calcareous samples exhibited elevated UCS, and shear strength values compared to their silica counterparts. This discrepancy underscores the inherent differences in mechanical behavior between these two types of sand, highlighting the need for tailored stabilization approaches. Moreover, the investigation delved into the failure patterns and microstructural changes within the stabilized samples, employing Scanning Electron Microscopy (SEM) for detailed analysis. This microscopic examination offered valuable insights into the efficacy of the stabilizing agents and their impact on the soil's mechanical properties. For instance, SEM imaging revealed significant bonding in fiber-reinforced samples, indicating enhanced load transfer mechanisms. Similarly, the presence of clusters of nano-silica particles adhering to sand particles showcased an improved cohesion within the stabilized soil. PU-stabilized samples, on the other hand, exhibited a cohesive layer enveloping sand particle, thereby enhancing interparticle connectivity and overall stability. The superior performance of PU over nano-silica was underscored by its ability to create a more cohesive matrix and foster stronger interparticle bonds, as evidenced by the SEM analysis. In conclusion, this study sheds light on the potential of innovative stabilization materials such as PU foam, nano-silica, and basalt fiber in bolstering the mechanical properties of soil. The findings not only offer valuable insights into the efficacy of these additives but also pave the way for the development of tailored soil stabilization techniques geared towards enhancing infrastructure resilience and sustainability.
Volume 0, Issue 0 (in press 2024)
Abstract
Bars with standard hooks in tension are often used to anchor reinforcing bars where concrete dimensions element are not sufficient to provide the required development length for straight reinforcement. In previous researches, concrete breakout failure was the predominant failure mode of hooked bars. Closely-spaced hooks provide a lower strength per hooked bar than more widely-spaced hooked bars because the area of the breakout surface is reduced for the more closely-spaced bars. The effects of fy of bars, spacing, and confinement by ties or stirrups have been updated to reflect test results, in 25.4.3.1 of ACI 318-19. In this formula, The confining reinforcement factor ψr is based on test results reported by Ajaam et al. (2018). Base on ACI 318-19 definition, Ath is total cross-sectional area of ties or stirrups confining hooked bars. Therefore crossties are not included in the relationship. The purpose of this study is to expand the understanding of the behavior of confinement effect of crossties on development length bars with 90 degree bent hooks in tension. In this study, 3 simulated beam-column joints were tested as a continuation of previous work by Ajaam et al. (2018). The results of this experimental study show that the ACI318-19 provisions underestimate the contribution of confinement by crossties on the development length bars with 90 degree bent hooks in tension.
Volume 1, Issue 2 (winter 2018)
Abstract
In general, temporary well plugging is essential for repairing of oil and gas wells due to their long life time. One of the newest methods used for this purpose is gel polymer plugging. The strength of the gel in the well conditions is one of the most important challenges in the application of gel polymer in the temporary well plugging in work over operation. In this study, silica nanoparticles were used to improve the strength of polymer hydrogels. The bottle and rheological tests were used to determine the gel strength in desired well conditions (high temperature and high salinity). Also, the gel strength properties and swelling behavior were studied in various conditions such as distilled water, formation water, tap water and oil. It was observed that the strength of the gel increased from 520Pa to about 36kPa (5000% increase) by adding nanoparticles. Also, the gel swelling in the aqueous solution has been significantly reduced. Based on the results obtained in this study, a polymer gel containing 9 wt.% of silica nanoparticles with structural strength and thermal stability at 90 °C was introduced for field studies.
Volume 3, Issue 3 (9-2015)
Abstract
The main diatomic structure-forming species of the Zayandehrud Reservoir was investigated by collecting samples from the surface, five, seven and 10 m depths from January 2011 to October 2012 along four linear transects. Asterionella formosa Hassall, Cyclotella ocellata Pantocsek and Fragilaria crotonensis Kitton were revealed as the three structure-forming species among diatomic algae in the reservoir. The number of these diatomic cells increased from the reservoir banks to its central areas, but their abundance was non-uniformly distributed at the 10-meter water column at different sites, except for C. ocellata that showed a practically uniform distribution at the peak of its maximum growth. Overall, the frequency and cover of these structure-forming diatoms changed under the influence of different abiotic variables such as electrical conductivity (EC) and nitrate (NO3-N).
Volume 3, Issue 3 (Summer 2018)
Abstract
Aims: Nowadays, with the advancement of life and more use of computers, musculoskeletal pains and disorders in computer users have also increased. Therefore, the aim of this study was to evaluate the status of musculoskeletal pains and disorders of computer users in health care providers working in comprehensive health centers of Sirjan.
Instruments & Methods: In this descriptive-analytical study, 110 health care providers working in comprehensive health centers of Sirjan were selected through simple random sampling. In order to evaluate musculoskeletal discomfort and pains, a Nordic questionnaire was used and a body map was used to determine the location of pain. Data analysis was performed, using SPSS software.
Findings: According to the findings, the highest pain and discomfort in neck was observed in 46.4% and, then, the pain in the shoulder region was 12.7%. In the lower limb, the most pain was reported in the waist with 18.2% and the least pain was reported in left wrist, both elbows and ankle.
Conclusion: Musculoskeletal discomforts are clearly seen in computer users; more discomforts and pains are observed in the upper body, especially in the neck and shoulders, and in most cases, this pain does not come from a particular illness or discomfort. Further studies are suggested to determine the status and non-ergonomic points of work in these individuals.
Volume 3, Issue 4 (12-2015)
Abstract
Volume 3, Issue 5 (8-2018)
Abstract
This article whit a descriptive-analytic method studied and compared two poet’s descriptions about the nature’s perspective. Conclusion: After comparing two poets various description subjects the research conclusions show that they enjoyed a nice and subtle humor as well as sweet speech and rich hobby, that provided for them a great power to describe the nature. Some of their descriptions of the nature have the color of the aristocracy. It seems that Mutran in describing some elements of the nature was under the influence of Arabic literature and Qaani influenced of Persian literature.
Volume 4, Issue 2 (4-2012)
Abstract
The relationship between the clergy as amajor social force and the Safavid state canlead our simple understandingto the exact understanding that may answer many of our questions in the social history of Iran. This paper considers the relations between the government and the clergy bystudying the fall and the rise of theclerics and the government relations, forms of their participation in policy, its development in the Safavid era and factors affecting on this evolution. This relationship can be investigated using the Tily’s theory and it can be saidthat this relationship takes many forms. Three overall types include membership in theoverall system of monarchy, influencing policy and resignation. Thismethodology is based on descriptive historical narrative approach.
Volume 4, Issue 2 (Spring 2019)
Abstract
Aims: Health care providers working in comprehensive health centers are considered as one of the main computer users and are subject to musculoskeletal disorders caused by computer work. This study was conducted to determining the effect of educational intervention based on the ergonomic principles of working with computers on knowledge, attitude and practice of health care providers working in comprehensive health centers of Sirjan , Iran.
Instrument & Methods: This study was performed with 110 health care providers working in comprehensive health centers of Sirjan. Census method was used for sampling. A man-made questionnaire was used to assess the effect of education on the improvement of behaviors preventing the MSD caused by working with computers. The training program in the intervention group consisted of three one-hour sessions. Data were collected at the beginning and 3 months after the intervention; and they were analyzed using spss16 software and Chi-square, independent T-test, and Wilcoxon and Mann-Whitney tests.
Findings: According to the results, despite the homogeneity of the two groups in terms of all the variables studied, the interventional group, after education, had a significant difference in knowledge, attitude and practice regarding observing the ergonomic principles of work with computers in comparison with the control group (p < 0.0001). Furthermore, in the intervention group three months after the training, there was a significant difference in the mean score of two variables of attitude and practice.
Conclusion: The results of this study showed that educational programs based on ergonomic principles of working with computers can promote behaviors preventing the MSD in computer users. Therefore, educational interventions are recommended in order to improve the behaviors preventing musculoskeletal disorders.
Volume 5, Issue 2 (7-2017)
Abstract
Abstract
Turkish writer Orhan Pamuk in his novel "My Name Is Red" by presenting a historical fiction story of a moment in the history of their country's artistic and cultural developments The contrast between traditional art and Western art in the form of a long narrative in the face of the Ottoman court painters Venetian painters (West) has written to the Heand fabls by referring to the distant past and telling stories that are rooted in history and dream and myiths, wider problems of modern society in a way one of the complexities of the world today is rebuilt, This open confrontation with the audience intelligently processing, This raises the question; indeed the author of the text intended to articulate what it is and what it is, how does Reproducing? Part of that comes from this study that The story ultimately is the paradox interpretation unwanted desires historical and cultural tradition and modernism. In a society where at least five centuries ago is still involved in this story. In this paper, we investigate and analyze the aspects of the interpretation of its dimensions. This paper includes descriptive analytical process would have benefited from the resource documentation library.
Volume 5, Issue 2 (Summer 2021)
Abstract
Research subject: Iran is a country with high potentials for access to renewable energy sources such as solar, hydropower, wind, and biomass. Biodiesel is one of the renewable fuels that has always been proposed as a suitable and stable alternative (non-toxic, safe, and degradable) to fossil fuels.
Research approach: The experiences of different countries in the use of edible sources for biodiesel production shows that the use of edible sources has caused problems such as lack of food resources for human communities, lack of feed for livestock, and upsetting the balance in the food industry, and it can lead to a significant increase in the price of these resources. Therefore, many researchers have proposed the use of non-edible sources to address these problems. So far, very large non-edible sources for biodiesel production have been identified. In this paper, non-edible sources of biodiesel that are produced or have the potential to be produced in Iran are introduced and studied and a potential assessment study is presented for them.
Main results: In this work, the non-edible sources for biodiesel production are classified into four categories: agricultural waste, waste cooking oils, microalgae, and non-edible seeds. These sources are compared based on various parameters such as oil percentage, oil content per hectare, biodiesel production efficiency, viscosity, saponification number, and cultivation period, which according to the results, non-edible seeds, especially Nowruzak seeds, Castor, and safflower have been identified as the most rational and sustainable sources of biodiesel production in Iran. The present work also deals with the policies and incentives that the responsible institutions can apply for the prosperity of the biodiesel industry.
Volume 5, Issue 4 (No.4 (Tome 20), (Articles in Persian) 2014)
Abstract
This paper aims to investigate the ways in which socio-linguistic parameters such as gender contribute into the turn organization of defense sessions. Interruption plays an important role in the organization of turn taking in the interactions of defense sessions. The current paper is then primarily focused on the description and analysis of interruptions in the interactions of dissertation defense sessions of Persian speakers using the “community of practice” approach. A number of discourse and pragmatic functions (e.g. defense, directiveness, cooperation, competition, etc.) have been identified for interruptions in relation to the power relations of interlocutors in the interactions. Apart from qualitative analysis, some quantitative findings have been provided for further clarification. The analysis of data shows that it is mainly the social status of a speaker that influences the types and frequency of interruption rather than his/her gender. In other words, the social variable does not play an important role in the interruption for turn organization in the defense sessions of Persian speakers.
Volume 6, Issue 3 (9-2017)
Abstract
To investigate the effect of different fertilizers on yield and health related traits of pomegranate fruit, a field experiment was carried out during 2014 and 2015 seasons on six years old pomegranate trees cv. ‘Bajestani’ growing in sandy loam soil under drip irrigation system in Khalilabad city, Khorasan, Iran. Organic fertilizers including: cow manure (25 kg/tree), vermicompost (5 kg/tree), and granulate humic (2 kg/tree) were applied without or with biofertilizers (azetobarvar, phosphobarvar and potabarvar at 1 liter/tree) by placement method. Results showed that plants treated with combination of organic and biofertilizers had higher yield and lower fruit drop than plants treated with organic fertilizers individually. The lowest fruit cracking (7.5%, 2.25%) as well as fruit infestation with Ectomyelois ceratoniae (Zeller) (27.5%, 25.34%) were observed in the plants treated with both biofertilizers and humic in 2014 and 2015, respectively. The most infestation to E. ceratoniae was observed in control treatment (38.07%, 31.44%) in both years, respectively. Fruit sunburn was not affected by nutrition of any type in both years. Results of leaf analysis revealed that plants treated by a combination of biofertilizer and humic had higher levels of macro and micronutrients compared with untreated plants. Altogether, our results suggest that biofertilizer in combination with organic fertilizers, especially granular humic, could be used in pomegranate orchards management to improve pomegranate yield, as well as to prevent crop losses resulting from cracking, nutrient deficiency and E. ceratoniae infestation.
Volume 6, Issue 3 (Summer 2018)
Abstract
Aims: Today, Mobile Health interventions as a group of Electronic Health interventions used to provide health information and improve health outcomes. The aim of this study was to determine the effectiveness of the Health Belief Model-based (HBM) education on self-care in diabetic patient via Telegram, among participants.
Materials and Methods: This quasi-experimental study was done from Jun 2016 to September 2017 in the health centers of Tabriz. Out of 20 health complexes in Tabriz, randomized (stepwise sampling) 5 complex selected. Then from each complex, 2 health center was selected randomly. With randomly sampling method, 68 patients with diabetes were selected (34 participants in the intervention group and 34 participants in the control group). In intervention group, educational text messages based on HBM was sent via Telegram during one month regularly. Three months later, both Intervention and control group completed researcher-made questionnaires by self-report. The data were analyzed by Chi-square test, paired t-test, Pearson’s test and SPSS 19 software.
Findings: There was no significant difference in several demographic characteristics between two groups. Comparison of the mean difference of knowledge and in HBM constructs before of intervention in the groups showed no significant difference (p>0.05). There was a significant mean difference in the HBM constructs between two groups after intervention (p<0.05). There were significant correlations between the HBM constructs (p<0.05).
Conclusion: Educational messages improve the perception constructs of HBM constructs for adopting self-care behaviors.
Volume 6, Issue 4 (No.4 (Tome 25), (Articles in Persian) 2015)
Abstract
This article analyzes the sources which have been cited in articles of Language Related Research. The research method is citation analysis, and data analysis was performed by Excel software. The results showed that in this period of time, 213 articles were published. 162 papers were presented as team work and the rest were individual studies .The books with 3112 citations and journal articles with over 1258 citations were more than from other sources. Among the cited sources of the Persian, 79.45 percent of the books were written and 20.54 percent were translation. Also, 97.49 percent (506) of the Persian journals articles were written and 2.50 percent (13 cases) have been translation.The highest cited author and translators were respectively, “Hamid Reza Shaeir” with 44 and “Farzaneh Taheri” with 10 citations. The highest cited book in Persian was “Semiotics of discours analysis” with 13 citations. The highest cited journals in Persian and English were the “Journal of Language Related Research” and “Language”, respectively with 76 and 29 citations.
Volume 6, Issue 4 (Fall 2018)
Abstract
Aims: Evaluating the factors affecting the mass movement and recognizing the regions sensitive to landslide are vital for planning, performing the construction projects, and providing proper management solutions in sensitive regions. The aim of the present study was to investigate the stability of the hillslope using the Stability Index Mapping (SINMAP) model to recognize the most important factor in causing the landslide by one-time sensitivity analysis method.
Materials & Methods: In the experimental research, the studied area included several watersheds in Javanrud, Kermanshah Province, Iran. Sensitivity analysis was performed for slope angle, internal friction angle, depth of soil, hydraulic conductivity, saturated storage ratio and rainfall. Accordingly, each of the mentioned parameters was changed by 10% to 75% compared to their initial value, assuming that other parameters remain constant. Then, the safety factor (FS) for each variation and the ratio of safety factor variations to initial FS were calculated.
Findings: The slope angle was the most important effective factor in causing the landslide in this region. The Second and the third factors were internal friction angle and saturated storage ratio, respectively.
Conclusion: The slope angle is the most important factor in causing the instability in all hillslopes, as where this factor is reduced by 20%, FS initial value increased by twice. After slope angle, soil internal friction angle has the highest importance, which shows a direct relationship with factor of safety. It means that, as this angle increase, stability of the hillslopes will also increase.
Volume 7, Issue 3 (Summer 2018)
Abstract
Aims: Heparin and EDTA salts are commonly used as anticoagulants for haematological studies in fish. This study aimed at investigating the effect of heparin and Ethylenediaminetetraacetic dihydrate (Na2EDTA) on some haematological parameters of Sterlet sturgeon (Acipenser ruthenus). Materials and Methods: In the current experimental study, the effect of heparin (10ml) and Na2EDTA (1mg/ml) was investigated on haematological parameters in Acipenser ruthenus. The blood samples were collected from 10 healthy fish with the average weight of 600.0±63.0g. The data were analyzed by SPSS 22 software, using one-way analysis of variance, independent t test, and Duncan's new multiple range test.
Findings: The number of red blood cells in samples containing Na2EDTA (845000±123532cell/mm3) was significantly lower than those of heparinized ones (1205000±86270; p<0.05). Mean haematocrit value for Na2EDTA samples (27.05%±0.46) was significantly higher than bloods preserved in heparin (23.62%±0.89%; p<0.05). In sample containing Na2EDTA, mean corpuscular volume (MCV) and lymphocyte (149.11±30.00ft and 93.25±1.55%, respectively) was significantly higher than the heparin sample (108.59±18.41ft and 87.25±1.72%, respectively; p<0.05). In sample containing Na2EDTA, the increase in size and haemolysis of red blood cells were observed, but the changes in the sample containing heparin did not differ significantly from that of the control group.
Conclusion: Na2EDTA has a negative effect on haematological parameters of Acipenser ruthenus, especially in morphological terms; so, it is not a suitable anticoagulant combination for blood analysis of this species. Heparin due to the smallest changes in shape and size of cell, as well as less effect on hematocrit, is an anticoagulant in sterilized fish haematological studies.
Volume 7, Issue 4 (Fall 2019)
Abstract
Aims: A pregnant woman’s nutrition is the main source for fetal development that affects both her and the fetus. The aim of this study was to investigate the effect of educational intervention on appropriate pregnancy weight gain in first-time pregnant women.
Materials & Methods: This quasi-experimental study was conducted on 86 first-time pregnant women who attended eight urban health centers in Khorram Darreh, Zanjan, Iran in 2018-2019. The subjects were selected by stratified sampling method and randomly divided into intervention (N=43) and control (N=43) groups. Before intervention, maternal body mass index was measured and the NUTRIKAP questionnaire was used on both groups. The education was provided by a trained nutritionist in three hour-long sessions in the first, second, and third trimesters of pregnancy. The posttest was done immediately after training. At the end of the third trimester, the weight of the pregnant women was measured in both groups. Data were analyzed by SPSS 16 software using independent T, Chi-Square, and Univariate ANCOVA tests.
Findings: By controlling the pre-test effect, after the intervention, the mean scores of knowledge (p=0.019) and practice (p<0.001) were significantly different between intervention and control groups, but there was no significant difference between the two groups in terms of attitude variable (p=0.311). The two groups had a statistically significant difference in weight gain during pregnancy (p<0.015).
Conclusion: The educational intervention is effective on appropriate pregnancy weight gain in first-time pregnant women.
Volume 8, Issue 1 (Winter 2020)
Abstract
This Article has no Abstract.
Volume 8, Issue 1 (Winter 2020)
Abstract
Aims: Motivation is increasing the feeling of attachment and involvement in a workplace. In the field of medicine, in which the lives of individuals are at stake, motivation of faculties, who are at the same time, educators and also physicians, becomes more critical. The aim of this research was to explore the medical faculties' perceive motivation in their academic lifework.
Participants & Methods: In this research was adopted a qualitative method by semi-structured interviewing 33 medicine faculties at Tehran University of Medical Sciences. The Braun and Clark's thematic analysis approach was used for data analysis to identify themes related to visible and invisible motivators in an academic lifework.
Findings: It was identified two major themes after analyzing the interviews: “Enterprise-level and visible motivators", and “Community- level and invisible motivators ". It was also identified five sub-themes: “Perceived need for authority and justice in scientific activities ", "Financial motives",” Incentive system (tangible and intangible support) of academic activities ",” Perceived need for a complementary atmosphere", and “Perceived need for a collaborative atmosphere".
Conclusion: Faculties' perception of job motivation goes beyond visible, self-interest, and enterprise level motivators. They also perceive community-level factors of working at complementary and collaborative atmosphere as major motivators.
