m. hassanzadeh

At present, Maximum Temperature Crystal Sensors (MTCS) are of great interest in the design and optimization of engines and turbines with high efficiency. These sensors are made in very small dimensions and can measure the maximum temperature in the desired location, for example inside the turbine. It is worth mentioning that a high fluence of fast neutrons is required to produce these sensors. The MTCS method is based on the high temperature phenomenon to restore changes made in the crystal lattice caused by neutron irradiation. Calculations of the maximum fast neutron flux for the diamond sample were performed using MCNP6 with the simulation of the core of the Tehran Research Reactor (TRR). Activity calculations were done using ORIGEN2, dose rate calculations through MCNP6, and temperature calculations with ANSYS software at different points of the sample. The highest fast neutron flux was calculated, and the activity of the sample decreased significantly after 40 days, with the dose rate at a distance of one meter reaching 1.4 µSv/h. Temperature calculations showed that the maximum temperature at the lowest speed of the channel was 402 K, which would not cause any thermal problems. Additionally, using the X-Ray diffraction (XRD) method, the lattice number and unit cell volume were calculated for the sample. The results obtained suggest that the diamond sample, from the perspective of neutronics, dosimetry, thermohydraulics, and changes in crystal lattice structure, can be recommended as a crystal sensor in the Tehran Research Reactor.

Shot-peening is a surface treatments utilized extensively in the industry to enhance the performance of metal parts against fatigue. This paper aimed to find the optimal parameters of the shot-peening process based on the finite elements model and the Taguchi method. The effects of three peening parameters (shot diameter, shot velocity, coverage percentage) are investigated on residual stress and roughness using Taguchi method. A new Taguchi technique is proposed by combining it with desirability function to optimize the shot-peening parameters that simultaneously provide two or more responses in an optimal mode. The results show that the coverage percentage has the most influence on the surface stress and maximum compressive stress whereas the velocity and diameter of the shot are the most effective parameters on the depth of compression stress. The shot velocity is the main factor of the surface roughness due to the shot peening. Through the proposed structure, optimal conditions can be obtained for surface stress and roughness simultaneously with high-coverage and low-velocity. Eventually, results reveal the effectiveness of the proposed strategy in stand point of saving time and cost.

The use of social media is expanding among students and different age groups. According to the published statistics, 67% of Iranian users of social networks are 12 to 17 years old. These people are of school age and most of them are students. Due to the few activities in the field of design and development of scientific social network for this age group, the need to pay attention to the design and implementation of social networks for students according to their needs and based on the values ​​of the Iranian society is felt more than ever. The purpose of this study is to identify the essential features of the student scientific social network at three levels: classroom, general and games and five management capabilities including identity information management, content management, communication management, search management and information management. Based on the aforementioned purpose, one question and four hypotheses were made.

As applied research, this study was carried out using exploratory mixed methods (qualitative-quantitative). In the qualitative stage, observation and structured interview were used as the basis of collecting data. The international scientific social networks were observed to develop the draft of interview questions and the relevant documents. To conduct the interview, a sample of 15 experts were selected purposefully and exposed to the structured interview. Finally, based on an analysis of the content of the social networks and the data collected from the interviews, management capabilities and their specific indicators were categorized. In the quantitative section, the research method was surveying and the data collection tool was a questionnaire. The opinions of two groups, including 15 experts of the previous stage of the study and 43 information technology officials of smart schools in Tehran regarding the importance of the indicators obtained for each of the management capabilities, were collected and prioritized. To validate the collected data in the qualitative section, the review method both by the interviewees and the peers was used. In the quantitative section, the content validity was formally approved by the experts and the reliability of the questionnaire was confirmed by Cronbach’s alpha coefficient.

The identified indicators for managerial capabilities in the main sections of the student scientific social network include 36 indicators in the classroom section, 37 indicators in the general section and 20 indicators in the game section. In each of the tripartite sections, the indicators related to the quintuple managerial capabilities were categorized.  11 indicators related to identifying information management are common to all three sections. The findings of the study show the importance of all indicators identified in the main sections of the student scientific social network. The highest average score obtained is related to the game section with an average of 8.66 versus an average of 8.30 for the general section and 8.45 for the classroom section. However, the degree of importance of those indicators is not the same for the respondents, and, accordingly, the indicators were prioritized. The total score of the indicators of the game section is more than the two general and classroom sections and the game capabilities can be used to advance educational goals. Moreover, it is possible to use the game factors and the capabilities that have been found in this study to further strengthen and support the students’ curriculum and general education.

The presence of appropriate indicators for the use of information literacy capabilities in the scientific social network, as well as the use of motivational and playful factors such as point wins can help to increase student participation in educational activities. The possibility of sharing learning problems, class participation in content production, providing information about the activities of friends and groups, the possibility of defining competitions and urban challenges, the possibility of sharing social issues and proposing challenges and competitions based on interests which, in this study, have been recommended as appropriate indicators in different sections of social network, can help in strengthening group participation, project-oriented learning, and group problem-solving. Also, sharing and communication capabilities can provide different students with equal opportunities to grow and learn. The framework proposed in this research can be used to evaluate the existing student scientific social networks. It can also provide a framework for designing and developing software for the student scientific social network based on the local characteristics and imitating the model of similar international student social networks.

In this study, a novel hybrid method was presented by considering the strengths and weaknesses of the two methods of the direct sensitivity method (DSM) and the complex variables method (CVM) and combining them to calculate shape sensitivity. The most of methods available are highly dependent on the values of step size variation related to the type of the problem. To validate the proposed method, some examples were analyzed by using the written finite element code. The comparison of results at solved problems indicated the independency of the proposed method from step size and only need to select an arbitrary small step size and the rounding error is negligible. It is a sign of its high computational performance which converges to reliable, stable, and high-precision results and saves calculation time compared to the other methods. The other advantages of the proposed method are the low volume of occupied memory and simplicity of implementation and its application in a wide range of engineering problems having simple and complicated equations.

This paper aimed to study the process of shot peening using the combination of the Finite Element Analysis (FEA) and the Response Surface Methodology (RSM). The shot velocity, shot diameter, coverage percentage and thickness are selected as process parameters. Residual compressive stresses and roughness are considered as response variables. Using FEA, shot peening is simulated and RSM is employed to determine the governing models between the response variables and the input parameters. The statistical analysis of the results reveals that: (1) the induced surface stress depends upon the coverage percentage and sample thickness, and it is independent of the shot velocity and shot diameter, (2) the maximum compression stress depends on the coverage percentage and shot diameter respectively, (3) the depth of maximum compressive stress depends on shot velocity and shot diameter respectively, (4) the depth of compressive stress is dependent on all four factors, (5) the roughness, Ra, is only dependent on the shot velocity. The results are in good agreement with the experimental data of the literature.

Exploring reading related elements in fictions published in Iran between 2011 and 2016.

Descriptive content analysis carried out for thirty-four of the highest print run titles, both original or translated into Persian. Reading related included reading elements included words such as reading, book, bookcase, library, librarian, bookshop, and bookseller. Data is gathered using a checklist.

791 codes were identified 234 of which belonged to the Persian and the rest (557 codes) the translated titles. The words "book" and "bookseller" found to have the highest and the lowest frequency in Persian fictions accordingly. The word "bookcase" had the lowest frequency among the translated fictions.

The presence of the reading elements in both groups of works is not acceptable. Overall, the translated titles contained more reading related elements.

Bordetellosis or turkey coryza, caused by Bordetella avium, has been an issue for turkey industry since its first description in 1967 when it was reported for the first time. Bordetella avium causes a highly contagious upper respiratory disease in turkeys. Therefore, this study aimed to isolate and characterize this species from commercial and backyard turkeys in Tehran, Isfahan, and Northern provinces of Iran. For the purpose of the study, 625 tracheal swabs were taken from 425 commercial poults and 200 backyard poults aged 2-6 weeks from September 2016 to September 2018. The swabs were immediately plated on MacConkey and blood agar plates and then pooled (5 swabs/pool) in tubes, containing 2 mL distilled water, to perform direct polymerase chain reaction (PCR) for the identification of B. avium. A total of 17 swab pools were found to be positive for B. avium. A subset of seven positive samples were sequenced for the flanking region of piuA gene. The analysis of the sequences indicated that the sequences were 98%, 96%, and 98% similar to B. avium 197N (AM167904.1), 4142 (AY925058.1), and 4156 (AY925068.1) sequences, respectively. To the best of our knowledge, the current study is the first attempt toward the molecular detection and characterization of B. avium in Iran. It is highly recommended to perform further studies to isolate, characterize, and differentiate the regional isolates in order to help the developing turkey industry of Iran meet the increasing demands for protein in the diet of the citizenry.

Although a dam’s structure has an important role in suppressing floods and providing water for activities such as agriculture, human consumption, industrial use, electricity generation and pisciculture, its break has an immense damage and loss of life when it occurs. In order to reduce the damaging effects of the dam break on the downstream places, it is necessary to provide the flood hazard map. For this purpose, in the first step, the output breach hydrograph of the Alavian dam was computed by the BREACH model under the overtopping scenario. In the next step, the breach hydrograph was routed through the downstream of the river by using HEC-RAS model. Finally, the ArcGISsoftware was utilized to prepare the flood mapping. The results of the present study illustrated that the Alavian dam is breached with the time of failure of 46 min and the peak discharge of about 66000 m3/s. Furthermore, according to the flood hazard map, most of the downstream inundation zones due to Alavian failure dam have been considered as the high hazard area.

Safety is one of the most critical issues in any test. The flexural test is a significant one to obtain material specifications. In this paper, a standard sample dose rate was calculated for the graphite flexural test in Tehran research reactor. Using different standards, the dose was computed at different distances and two periods of radiation, 15-40 days. Our calculations were performed with the ORIGEN and MCNPX codes. The impurity amounts of the material were measured by two methods of X-ray Fluorescence (XRF) and Inductively Coupled Plasma, Atomic Emission Spectroscopy (ICP-AES). The obtained results show that the Claiborne & Trubey standard is more stringent than other standards, and it has less than 2 μSv/h dose with the observance of 100cm distance and 20 days after irradiation. Moreover, calculations of the transfer chamber indicate that there is no limitation for the transport of the samples. Finally, it can be concluded that the considered method of this research can be used also for other materials at the reactor core.

Trifluralin is one of the important soil applied selective, pre-sowing or pre-emergence herbicide used to control many annual grasses and broadleaf weeds in a large variety of arable and horticultural crops. It is a generally regarded as a moderately persistence herbicide with a half-life of 1.5 to 6.5 months. Several factors determine the length of time herbicides persist and their carryover. These factors fall into three categories: soil factors, climatic conditions, and herbicide properties. Soil related factors including soil temperature, soil texture, and soil moisture and soil organic matter are the most important factors in herbicide persistence. However physicochemical of herbicide such as absorption properties are also important factor. So different herbicides may have different persistence in soil and have different effects on agroecosytems and also on subsequent rotational crops. Normally residual herbicides extend the period of weed control, and increase the efficiency of weed management efforts. However, they may persist longer than desired and injure or kill subsequent rotational crops. Most herbicide labels include crop rotation guidelines, but rotational restrictions are often not listed for many crops. Several experiments have demonstrated that trifluralin herbicide can per sist in the soil and carryover to affect succeeding crops. Some crops tolerate a particular herbicide residue and can be replanted soon after that herbicide is applied, while other crops remain sensitive to the herbicide for a longer time after application. This experiment was conducted to investigation of some plants sensitivity to soil residue of trifluralin in greenhouse conditions. To evaluate the sensitivity of some plants to simulated trifluralin soil residues, an experiment was conducted based on completely randomized design as factorial layout and four replications in Research Greenhouse of Faculty of Agriculture, Ferdowsi University of Mashhad. Treatments included seven plants (sorghum, millet, barley, wheat, oat, alfalfa and cucumber) and eight levels of concentrations of simulated trifluralin residue in soil (0, 0.002, 0.004, 0.021, 0.043, 0.046, 0.086 and 0.129 mg a.i. kg-1 soil). Trifluralin aquatic solution incorporated to soil and transported to the plastic pots with a 15-cm diameter. Plants emergence percentage was recorded and their shoot and root biomass were measured 35 days after emergence. The data were statistically analyzed using analysis of variance, and differences among mean values of treatments were compared by Duncan's test using SAS software. For determination the required dose of herbicides to reduce 50% of plants response (ED50), the dose response curves were fitted simultaneously using the following three-parameter logistic dose-response model with the lower limit equal to zero.
Where f is the response (above ground dry weight and root dry weight), d is the upper limit, b is the curve slope, e denotes the dose required to give a response halfway between the upper and lower limits (ED50); and x is the herbicide concentration in soil. The validity of the above model and the comparisons between the parameters were made using F-test for lack-of-fit with a 5% level of significance. Results showed that trifluralin residue decreased plants mergence and shoot and root biomass. By increasing the trifluralin soil residue, reduced all above mentioned parameters significantly (p≤0.01) in all plants. Plants showed different response (p≤0.01) to trifluralin soil residue. The highest and the lowest percent shoot and root dry weight to control treatment were observed in alfafa and sorghum, respectively. Based on ED50 parameter, alfafa (0.164 mg a.i. trifluralin kg-1 soil) and sorghum (0.048 mg a.i. trifluralin kg -1 soil) appeared the most tolerant and the most sensitive plants to trifluraline soil residue, respectively. The other crops sensitivity to trifluralin in soil residue followed the following order: sorghum> millet >barley> wild oat > wheat > cucumber >alfafa. According to the results, trifluralin residue in soil can affect the growth of rotational crops specially sorghum and millet. Therefore, regarding to the distance planting of sensitive crops after trifluralin application is necessary. Based on the results, plant response to trifluralin residues in soil were different significantly. However some sensitive plants such as sorghum and millet may be used for soil residue of trifluraline in bioassay experiments.

Soil cement is a mixture of Portland cement, soil and water, the constituents of which, due to the hydration of cement and compaction, bond together and make a dense and durable composition with low permeability and abrasion resistance. According to the de nition of ACI 116R, soil cement is a mixture of soil and a certain amount of cement and water which has been compacted to a high density. A more comprehensive de nition has been provided in ACI 230 IR, which de nes soil cement as a hard material with speci c engineering properties that is produced by the mixing, compaction and curing of soil, aggregate, Portland cement, additives and wa- ter. They are similar to roller compacted concrete; the main di erence between them being, however, the type and size of aggregate particles. Soil cement is principally made of round natural nes, while roller compacted con- crete is made of particles with a size of up to 19 mm. The soil cement mixture is usually used as protection for earth embankment slopes, while roller compacted con- crete is mostly used in massive elements such as gravity dams. All types of soil can be used in soil cement con- struction, except organic and plastic soil and reactive sand. The most ecient soils are those containing 5 to 35% of nes, passing sieve 200. However, soil containing more than 2% organic material is strictly unacceptable. Soil cement application in dam and pavement construc- tion has grown. Previous studies have investigated the e ects of cement content, water to cement ratio, and compaction level, on the strength of soil cement mix- tures. Some other factors a ecting the strength of soil cement are pozzolans and chemical additives which are not usually economical for use in large civil projects. In this research, the e ects of plasticity index and sand equivalent of soils on uncon ned compressive and ex- ural strength have been investigated. The results show that the compressive and exural strength of soil cement mixtures is dependent on the plasticity index and sand equivalent. Also, a numerical model developed for the co er dam of the Bakhtiari dam, and results, show that its structure is stable with soil cement material.

Investigation of Persian Gulf seawater corrosion effect on the carbon steels and welded pieces used in construction of metallic storage tanks is important from this point of view that this investigation may result in using this seawater to do hydro test of these tanks. If the results of this evaluation be positive, it will have lots of economic and environmental advantages. In order to achieve this target in this study, at first a 15 mm thickness plate of ASTM A283 Grade C low carbon steel was welded by E7018 electrode then quality controlled by radiography test and its microstructure evaluated by macro and micro etch tests and also hardness test was done for it. Furthermore chemical composition, pH, conductivity and SRB amount within the water has been measured too. Then corrosion rates for each one of these mentioned steel and electrode in Persian Gulf seawater were measured by electrochemical method of linear polarization resistance and also immersion test. Then corrosion product and corroded surface were analyzed by EDS and SEM methods. Results of polarization and immersion tests proved that E7018 electrode is anode compared to ASTM A283 Grade C steel and this result was confirmed by SEM images.

In recent years, many attempts have been conducted to use accrual accounting in the reporting system of the public sector of some countries such as Iran. Since the main purpose of accounting and financial reporting system in the Universities of Medical Sciences is to provide the information which will assist managers effectively in implementing accountability, the present study examines the effect of implementing accrual accounting on the accountability of managers of the Universities of Medical Sciences in the North-west of Iran.

The present research is a field survey. The population of this research consist of all managers of the North-west Universities of Medical Sciences of Iran in 2014 among 341 subjects. By using the table of determining sample size by Morgan and Krejcie, 181 subjects were achieved as the sample size, and the units of samples were selected through cluster sampling method. Data collection tools include a researcher-made questionnaire. In order to analyze the data, the descriptive statistics, one-sample t-test, t-test for independent groups, and ANOVA have been used by SPSS Software Version 20.

The implementation of accrual accounting in the Universities of Medical Sciences has a significant and positive effect on seven dimensions of the accountability of managers including public, financial, professional, legal, social, and operational dimensions.

From the viewpoints of managers in the Universities of Medical Sciences, the implementation of accrual accounting has a significant and positive effect on accountability; therefore, the implementation of accrual accounting leads to increase the level of accountability.

In a cross over study eight normal human volunteers were employed. The bioavailability of different commercial brands of cephalexin capsules were examined. The relative bioavailability offour brand (J.I,J.II,L.I,L.II) manufactured by two different domestic cornpai.ies were compaired with one brand (Keflex) which was manufacrurea by Lilly pharmaceutical company, England. The plasma and urine cephalexin concentration were determined by microbiological assay (disk diffusion) using Sarcina LuteaATCC 9341 as test organism. Plasma and urine data were used to evaluate various pharmacokinetic parameters cephalexin including K,tl/':b C1/F, Vd/F, T max, CmaxAUC and F (relative).
Results obtained from urinary data were supported the plasma data. The analysis of variance, to compare relative bioavailability and other pharmacokinetic parameters between tested samples were performed. These information indicates that there are no significant differences between the five different tested brands and they are bioequivalent. Therefore it can be suggested that brands (J.I,J.II,L.I,L.II) which formulated by domestic manufactures are bioequivalent and comparable to each other and to the one formulated by Lilly pharmaceutical company.