Calculation of dpa rate in graphite box of Tehran Research Reactor(TRR)

Radiation damage is an important factor that must be considered while designing nuclear facilities and nuclear materials. In this study, radiation damage is investigated in graphite, which is used as a neutron reflector in the Tehran Research Reactor (TRR) core. Radiation damage is shown by displacement per atom (dpa) unit. A cross section of the material was created by using the SPECOMP code. The concentration of impurities present in the non-irradiated graphite was measured by using the ICP-AES method. In the present study the MCNPX code had identified the most sensitive location for radiation damage inside the reactor core. Subsequently, the radiation damage (spectral-averaged dpa values) in the aforementioned location was calculated by using the SPECTER, SRIM Monte Carlo codes, and Norgett, Robinson and Torrens (NRT) model. The results of “Ion Distribution and Quick Calculation of Damage”(QD) method groups had a minor difference with the results of the SPECTER code and NRT model. The maximum radiation damage rate calculated for the graphite present in the TRR core was 1.567 9 10^-8 dpa/s. Finally, hydrogen retention was calculated as a function of the irradiation time.

Effective point kinetic parameters calculation in Tehran research reactor using deterministic and probabilistic methods

The exact calculation of point kinetic parameters is very important in nuclear reactor safety assessment, and most sophisticated safety codes such as RELAP5, PARCS,DYN3D, and PARET are using these parameters in their dynamic models. These parameters include effective delayed neutron fractions as well as mean generation time.These parameters are adjoint-weighted, and adjoint flux is employed as a weighting function in their evaluation.Adjoint flux calculation is an easy task for most of deterministic codes, but its evaluation is cumbersome for Monte Carlo codes. However, in recent years, some sophisticated techniques have been proposed for Monte Carlo-based point kinetic parameters calculation without any need of adjoint flux. The most straightforward scheme is known as the ‘‘prompt method'' and has been used widely in literature. The main objective of this article is dedicated to point kinetic parameters calculation in Tehran research reactor(TRR) using deterministic as well as probabilistic techniques. WIMS-D5B and CITATION codes have been used in deterministic calculation of forward and adjoint fluxes in the TRR core. On the other hand, the MCNP Monte Carlo code has been employed in the ‘‘prompt method''scheme for effective delayed neutron fraction evaluation.Deterministic results have been cross-checked with probabilistic ones and validated with SAR and experimental data. In comparison with experimental results, the relativedifferences of deterministic as well as probabilistic methods are 7.6 and 3.2%, respectively. These quantities are10.7 and 6.4%, respectively, in comparison with SAR report.

The impact of land afforestation on carbon stocks surrounding Tehran,Iran

The city of Tehran, like many polluted metropolises of the world, has higher emissions of greenhouse gases than other cities in Iran, due to heavy consumption of fossil fuel and landuse changes. To estimate carbon sequestration in two 40 year-old stands of plantedCupressus arizonica andFraxinus rotundifolia in degraded lands surrounding Tehran , sampling of above- and below- ground biomass, soil （at two depths of 0-15 and 15-30 cm）, and leaf litter was done by systematic random sampling. The total carbon stocks ofC. arizonica and F. rotundifolia stands were respectively 328.20 and 150.69 Mg·ha-1. The aboveground biomass with 233.16（71%） Mg·ha-1 inC. arizonica and 88.16 （58.50%） Mg·ha-1 inF. rotundifolia contributed the most shares to carbon sequestration. The diameter at breast height, total height, basal area, total volume, and biomass ofC. arizonica were significantly （p 〈0.01） higher than those ofF. rotundifolia. Also the depth of 0-30 cm of soil contributed between 18.29 % and 32.15 % of total ecosystem carbon, respectively. The economic value of carbon sequestration in the two stands in 2011 was calculated at 3.5 and 2.5 million dollars, respectively. Our results indicate that afforestation of the degraded land surrounding Tehran would sequester more carbon than would continuously degraded land, the current status quo. These stands can absorb atmospheric CO2at different rates, thus tree species selection and stand development should be considered in planning future afforestation projects.

Synoptic-Thermodynamic Analysis of Pervasive Hailstorm Case Study: Tehran, March 30, 2015

The objective here is to assess the atmospheric evaluations with respect to the perilous hailstorm phenomenon in Tehran. To accomplish this study, the available data regarding 9 (WW) present weather codes that reveal the hailstorm phenomenon with different intensities in 3 hrs observations for 6 meteorological stations of Tehran and vicinity for the period between 1985-2015 are applied. It is revealed that hail occurrence in Tehran is at its maximum in transition seasons of spring and fall between the hrs. 6 - 18 (UTC). It is found that the instability indexes intensify in the afternoon with a higher atmospheric flotation indicative of the possibility in occurrence of thunder hailstorm. Synoptic assessments point to the fact that the synoptic pattern created this thunder storm due to expansion of two: low-pressure cores over Arabia and North-Europe and the cold high-pressure over South Russia with a NS orientation have developed an intense pressure gradient over Tehran province. The study area being located at the left exit of sub-tropical jet stream has made a Baroclinic atmosphere condition on Tehran province. Access to great humidity resources of Mediterranean and Black seas and a drastic decrease of temperature at the upper level of the cloud verifies the hail occurrence on March 30th of 2015 in Tehran.

Fault Movement Potentials in the Tehran-Semnan Region (North Iran)

The major Quaternary faults in the Tehran-Semnan region can be classified based on their strikes into three sets: northeast-southwest, northwest-southeast and east-west. In this paper, we use a model to evaluate fault movement potential (FMP). Their theoretical model is based on the relationship between fault geometrical characteristics and regional tectonic stress field. The results show that The Mosha, Emam Zadeh Davood and Pourlcan-Vardij fault zones have high FMP (0.9 or 90%) and the Parchin fault zone has very low FMP (0.0 - 0.1) in the area.

Seismic hazard assessment of Tehran,Iran with emphasis on near-fault rupture directivity effects

Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is estimated that in the scenario of activation of the North Tehran fault, many structures in Tehran will collapse. Therefore, it is necessary to incorporate the near field rupture directivity effects of this fault into the seismic hazard assessment of important sites in Tehran. In this study, using calculations coded in MATLAB, Probabilistic Seismic Hazard Analysis （PSHA） is conducted for an important site in Tehran. Following that, deaggregation technique is performed on PSHA and the contribution of seis- mic scenarios to hazard is obtained in the range of distance and magnitude. After identifying the North Tehran fault as the most hazardous source affecting the site in 10000-year return period, rupture directivity effects of this fault is incorporated into the seismic hazard assessment using Somerville et al. （1997） model with broadband approach and Shahi and Baker （2011） model with narrowband approach. The results show that the narrowband approach caused a 27% increase in the peak of response spectrum in 10000-year return period compared with the conventional PSHA. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.

Self Evaluation in Department of Communicable Diseases, Faculty of Medicine, Tehran University of Medical Sciences

Introduction: Self evaluation is a process that defines and collects required data to judge about decision making issues at educational system on whether the educational department is fit to educate students? The objective of this study was determining the quality of the structural elements of the department of Communicable Diseases & determining the strengths, weaknesses, opportunities and threats to improve the quality of activities in the department under research. Materials and Methods: The employed method was Mixed methods (qualitative & quantitative research), on the basis of 10 procedural steps and within 8 sections dealing with evaluated factors;such as 1) organizational and management structure 2) scientific board members 3) students 4) Manpower 5) Space of educational research and health care 6) Equipment 7) curriculum 8) satisfaction of graduates, which were studied using 61 criteria and 172 indicators. Five-point Likert Scale was used for the responses in the questionnaire (1 - 1.75 = undesirable, to 4.2 - 5 completely desirable). Finally the data were analyzed using descriptive statistics indices and the assessment software of the Educational Development Center of TUMS. The instruments used in this method included assessment software, interview, observation and self-prepared questionnaire which consisted of 7 questionnaires and 2 check lists. Finding: The results of the research showed that general average of 8 investigating sections was 56.9% as a rather desirable research work. Conclusions: Therefore, it was concluded that function of the educational management in that group was directly in line with evaluation process, but continuing the process of evaluation seems necessary.

Evaluating the average access to care and continuity of care patients in Tehran teaching hospitals

Background: Standards of Joint Commission International emphasize on the organizational performance level in basic functional domains including patient right, patient care, medical safety and infection control. These standards are focused on two principles: expectations of the actual organizational performance and assessment of organizational capabilities to provide high quality and safe health care services. The aim of this study is to evaluate the possibility of improvement in Access to Care and Continuity of Care for patients (ACC) in teaching hospitals of Tehran University of Medical Sciences. Methods: This cross-sectional study was conducted in hospitals affiliated to Tehran University of Medical Sciences during 2012. Data collection was performed using author-designed questionnaire of “Access to Care and Continuity of Care patients” based on JCI standards (2013). A total of 171 questionnaires were sent to 26 hospitals and 154 (90%) questionnaires were successfully completed and used for data analysis. The questionnaire was reviewed by experts and the Cronbach’s alpha was calculated to be 0.967. The effects of the two variables of hospital type (general, specialty) and the number of beds on mean scores of ACC standards and each of its domains were analyzed using T-test or Mann-Whitney test depending on the distribution due to Kolmogorov-Smirnov test result. Results: In general, the mean of ACC standards was found comprehendible and applicable by 82.3 (SD = 11) of the respondents. The highest and lowest mean scores of ACC questions belonged to hospitals H21 (90 ± 6) and H14 (67 ± 12), respectively. There were not any significant effects of hospital type and the number of beds on the ACC scores. Conclusion: There was not any important effect of hospital type and bed numbers on ACC, although there was a 9%-15% possibility of improvement in accreditation scores of ACC standards in hospitals of Tehran University of Medical Sciences. A complete accreditation score in this domain didn’t seem achievable in these hospitals. However, it is proposed that future managerial planning of the studied hospitals lead to a complete accreditation score.

Assessing Demographic Factors Related to Maternal Mortality in Tehran Province, Iran from 2008 to 2011

The rate of maternal mortality due to complications of pregnancy and delivery is one of the most significant indicators showing the development state of countries. The purpose of the present study is to assess important indicators of maternal health and predisposing factors of maternal mortality in Tehran province from 2008 to 2011. The present study is a case-control one. All mothers who had lost their life (n = 113) were selected through census and survived mothers (n = 327) through randomized stratified sampling. Statistical analysis was performed using SPSS V.22, X2 test, Fishers exact test and Logistic regression. The rate of maternal mortality was the highest (29.2%) in 2009 and the lowest (20.4%) in 2011. Variables type of maternity hospital (P-value = 0.036), maternal education (P-value < 0.001), husband’s education (P-value < 0.001) had a significant relation to maternal mortality. Logistic regression analysis showed that there is a relationship between the education level of the husband and maternal mortality. Considering the factors affecting maternal mortality, promoting hospital services, improving skills and knowledge of doctors, midwives and nurses and strengthening educational programs for the illiterate are the most effective measures to reduce maternal mortality.

Clinical and molecular features of human cystic echinococcosis in Tehran,Iran,2011-2019

Objective:To evaluate the clinical and molecular features of human cystic echinococcosis in Tehran,Iran.Methods:In this cross-sectional study,all human cystic echinococcosis patients admitted to Tehran’s hospitals from 2011 to 2019 were enrolled,and demographic characteristics,clinical findings,and laboratory data were collected.Formalinfixed,paraffin-embedded and fresh tissue samples of 175 cystic echinococcosis patients were evaluated for molecular characterization.The samples’isolated DNA was used to amplify cytochrome c oxidaseⅠand NADH dehydrogenase subunitⅠgenes.Also,the morphological features of fresh samples were examined.Results:In total,175 patients with a mean age of 45(9-98)years were admitted to Tehran’s hospitals diagnosed with cystic echinococcosis.Moreover,the highest(26.9%)and the lowest(2.9%)prevalence of cystic echinococcosis cases were in the 16-30 and 1-15 years range,respectively.Male/female ratio was 0.96(49.1%vs.50.9%).The liver was affected in 92 patients(52.6%),and two or more organs were infected in 7 patients(4.0%).The cysts’diameter varied from 1 to 25 cm,and 96.0%of the patients had a single hydatid cyst.All patients underwent radical surgery and the PAIR technique was applied for all cases.No significant difference was observed between the protoscolex hooks of pulmonary and hepatic cysts.G1-G3 had the highest percentage(99.4%)over other identified G6 genotypes(0.6%).Conclusions:The sheep-dog cycle plays an important role in transmitting the human cystic echinococcosis infection in Tehran.

The Transverse Topographic Symmetry Factor of Darakeh Stream in the North Tehran, Iran

The study area?is located in the north Tehran, Iran. Calculation of transverse topographic symmetry factor (T) is suitable for rapid assessment of active tectonics. Therefore, transverse topographic symmetry factors have?beencalculated for the Darakeh stream. The study area is located in the Tehran Piedmont and transverse topographic symmetry factor?is calculated for it. Based on values of this index, there is high relative tectonic activity level. This condition can be related to existence of a blind north-south striking fault which it may be buried by alluvium of the Darakeh stream. Dendritic drainage pattern of Darakeh stream and the fact that the western tributaries are longer than the eastern tributaries provide indirect evidence of ground tilting toward the east. Also, based on our results, most part of the study area have got high tectonic activity that it is compatible with its tectonic setting on the Tehran in north Iran.

Zoning of CO Emissions in Tehran in the Medium Term by Using Third Quartile as the Exposure Candidate

CO is one of the main air pollutant which leads to many problems for human. Mega cities such as Tehran have critical issues by increasing the vehicles, fuel usage and urban area expansion. Hence, to have a clear view points on the pattern of CO concentration in Tehran, the data of 14 air quality concentration centers in a midterm period (2009 and 2012) are used. The main novelty of this research is using the third quartile (Q3) as the pollution indicator which leads to more accurate results based on the exposure pattern in a day. Additionally, by Spline interpolation model and using ArcGIS software the zoning maps to show the CO concentration in urban area are illustrated and discussed. Using Q3 instead of the mean values showed more accurate results due to the exposure patterns. Due to the results, the CO concentration shows a downward trend and the most changes are in the Western side of the city.

The Chronological Process of Changes in Iranian Urban Spaces – A Case Study: Tehran and Its Squares

One of the key current challenges in urban design and planning worldwide is the notion of “scale”, which is important in various levels of decision making for urban spaces such as squares. How “scale” is defined in the field of design and planning will lead to divergent approaches towards urban spaces, such as adaptation, obeying, alteration, and neglect. In order to create successful urban spaces with suitable scales that respond to users’ expectations, it is necessary to minimize the gap between the subjectivity and objectivity, and to this end, this paper studies the chronological process of such changes in Tehran and their impact on the design of one type of space: the urban square. Furthermore, this paper aims to identify if and how the subjectivity and objectivity of squares in Tehran have been changed as a result of chronological phases of transformation, particularly since the foundation of the city in 1524. The findings reveal how aspects of the city’s squares are disappearing, but need to be revived to achieve socio-cultural sustainability. The main methods applied include a review of the related literature, an appropriate analysis, and direct observation.

Rethinking Iranian Urban Housing -- A Review on the Housing Attributes under the Current Development of Tehran

Housing in the private sector in the metropolitan of Tehran in the past decades has been very much tied to the economical considerations, The current urban and building standards and regulations are believed to have very much contributed to the undermining the many social, environmental and visual potentials of the neighborhoods and to what we face today as congested apartment atmosphere where and the monotonous character of most of the neighborhoods as a result of the very same plans and regulations applied to their development namely the setbacks, land coverage ratios and floor to land area ratios with no regard to the very different characters many of these neighborhoods once had, either traditional and long-established or scenic and natural. The purpose of this paper is to briefly review the current state and trend of urban housing in Tehran and search for practical measures to improve the environment and character of urban housing in the city.

Inclusiveness in City Centre-A Case Study: 30-E-Tir Street in Tehran

City centres in today’s big cities,particularly in metropolises and megalopolises,play a crucial role in revival of human scale in an urban context.Nowadays,a city centre that corresponds to needs of various groups of users,contributes to creating a safe,healthy,vibrant,inclusive and sustainable city.Accordingly,identification of the major and minor groups of users of city centres as well as their likes,dislikes and preferences is a primary step.To this end,this paper investigates the city centre of Tehran and a recently pedestrianised street called 30-E-Tir.With a focus on the three indicators of age,gender and speed,this paper aims to elucidate the existing divergent groups of users of 30-E-Tir and their physical,mental,and spiritual expectations of this street.This 1.3-km street-as a linear path incorporating food&junk food kiosks and the associated small-scale canopies,and flagstone floorscaping-passes through many famous museums of Tehran.These specific features have converted 30-E-Tir Street into a convivial destination point for Tehranians.The existing problems,however,necessitate a detailed investigation of the current situation.The applied methodology for this qualitative-quantitative analysis of the present condition includes the literature review and the related analysis,direct appraisal,photography,and dot-based analysis.

First Report of Polymelia in a DSH Kitten in Tehran,Iran

Congenital malformations are intrinsic structural abnormalities and variations of organs,tissue and/or body systems that can occur during the embryonic development of all animal species,and may be partial or total.Polymelia in humans is a rare condition with little information about its occurrence.There is no categorization of data on its occurrence along with other congenital malformations.There are few reports of this occurring in cows,sheep,amphibians,reptiles,birds,dogs and cats.In Jan 2018,a DSH(Short Hair Domestic)kitten found on a street was referred to a veterinary hospital in Tehran with symptoms of rigid mass and deformity in the pelvic region.With lateral and ventrodorsal positioning,the case was sent to the radiology department and examined under the plain radiograph.Findings included two underdeveloped hindlimbs associated with normal left hindlimb showing the congenital deformity and malformations,deformity and underdevelopment of right hemipelvis,the fusion of first and second lumbar vertebrae and kyphosis due to lumbar vertebrae deformity.Through the radiological examinations,the results show that the rigid mass was actually the third hindlimb and the condition is called polymelia.This is the first reported case of polymelia in a domestic shorthair cat in Tehran,Iran.

Effects of cooling channel blockage on fuel plate temperature in Tehran Research Reactor

In this study, the variation of the temperature distribution of the fuel plate in Tehran Research Reactor core was studied in case of coolant channels blockage. While the experimental method is not possible, both the analytical and simulation methods were used to obtain the more reliable data. The results show that one channel blockage will increase the fuel temperature to about 100%, but it does not lead to clad melt down still. With further calculation and simulation it is understood that if the coolant velocity drops to 90% of its nominal value, it may causes the clad melting down. At least two channels with complete blockage even at the positions far from the core center can also melt down the clad.

Long term exposure to ambient air particulate matter and mortality effects in Megacity of Tehran,Iran:2012-2017

Ambient particulate matter(PM)is the major environmental concern in Tehran,Iran.Exposure to such particles is a serious global health concern and substantial evidence indicates that exposure to particulate matter contributes to cardiovascular and respiratory disease.Here,we provide a detailed health impact of ambient air pollution in Tehran by linking PM pollution with mortality caused by cardiovascular and respiratory disease.Air quality data of PM obtained from Tehran Air Quality Monitoring Stations(TAQMSs)during 2012–2017.Data mining methods conducted by Spatio-temporal outlier detection and“Air Pollution and Health:a European Approach(APHEA)project”was applied to impute missing values.Time-series data were analyzed to estimate the associations between PM pollution and cause-specific mortality at different lags in Tehran.Based on descriptive analysis,PM_(2.5) is expected to be a major influencing factor in the increased cardiovascular-related death(CVD)and respiratory dysfunction related death(RD)deaths.The cross-correlation analysis showed the same source for PM_(2.5) and PM_(10) in the ambient air of Tehran.Also,the results indicated delays of about 7-15 days from the increased concentrations of PMs and the observed rising in CVD and RD death.Trend analysis showed a more decreasing trend for PM_(2.5) pollutions than PM_(10) pollution and a slightly increasing trend for cause-specific deaths during 2012-2017.Long term exposure to high PM levels increases the CVD and RD deaths and control strategies along with control regulations should be considered to control PM.

Assessing renewable-energy potential and feasibility in Tehran’s buildings

This article examines the results of using renewable energy to reduce the energy consumption of buildings significantly.In particular,it looks at the results in a country such as Iran,which has a high potential for using solar energy.A comparison of the energy consumption of selected case samples based on the type of ownership of private,government and municipal buildings in 22 districts of Tehran has been analysed.Using data for energy consumption and Strengths,Weaknesses,Opportunities,Threats analysis includes open and usable spaces for installing renewable-energy systems in 10%of public buildings,4%of private facilities and 10%of municipal buildings.The results of this study show that the average energy consumption of buildings in Tehran is almost four times the global average.Iran has~300 days of sunlight for installing solar panels in any place where solar energy is in direct contact with the Sun.Thus,it allows the building to use the energy absorbed by the discussions in all seasons.In 2050,this country could play a decisive role in producing renewable energy.In addition,solar energy may reduce fossil-fuel consumption and production costs.

Prediction of subsidence risk by FMEA using artificial neural network and fuzzy inference system

Construction of metro tunnels in dense and crowded urban areas is faced with many risks, such as sub- sidence. The purpose of this paper was the prediction of subsidence risk by failure mode and effect anal- ysis （FMEA） and fuzzy inference system （FIS）. Fuzzy theory will be able to model uncertainties. Fuzzy FMEA provides a tool that can work in a better way with vague concepts and without sufficient informa- tion than conventional FMEA. In this paper, S and D are obtained from fuzzy rules and 0 is obtained from artificial neural network （ANN）. FMEA is performed by developing a fuzzy risk priority number （FRPN）. The FRPN for two stations in Tehran No.4 subway line is 3.1 and 5.5, respectively. To investigate the suit- ability of this approach, the predictions by FMEA have been compared with actual data. The results show that this method can be useful in the prediction of subsidence risk in urban tunnels.