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Showing 13 results for Safarzadeh


Volume 3, Issue 3 (Summer 2023)
Abstract

Effective Altruism has discussed helping others both in the domain of theoretical foundations and in the domain of practical foundations. In fact, helping others includes helping other humans, animals, the environment, and any other thing that improves the conditions of men and the world, and the discussion of this issue is of a background as ancient as human existence itself. The Most Good You Can Do by Peter Singer, one of the contemporary thinkers in practical ethics, contains four parts and fifteen chapters. The book has discussed the issue of helping others in a very proper and, of course, effective and applied manner, and it is unique in its specific domain; but the most significant point of weakness of this book is its negligence of the role of global organizations in prevention from war, etc., which in turn can play an effective and even fundamental role in the domain of altruism. 
 

Volume 8, Issue 3 (Summer 2023)
Abstract

Aim: Adolescence is a very sensitive and important period in everybody’s life, particularly in individuals with disabilities, because it can significantly impact their experiences. The present study aimed to investigate the mediating role of academic self-efficacy in the relationship between curiosity and academic well-being among adolescents with physical and motor disabilities.
Method and Materials: The statistical population in this descriptive correlational study included all the adolescents 12-18 years old with physical and motor disabilities in Khuzestan Province of Iran during the academic year 2022–2023. The study sample consisted of 282 adolescents who selected using purposive sampling. The research instruments included the Academic Wellbeing Questionnaire, the two-dimensional Curiosity and Discovery Inventory, and the Students’ Academic Self-Efficacy Questionnaire (SASEQ). The proposed model was evaluated using structural equation modeling (SEM).
Findings: The results revealed that there was a significant direct path from curiosity to academic self-efficacy (P<0.001). However, the direct relationship between curiosity and academic well-being was not significant. In addition, a significant relationship, mediated by academic self-efficacy was found between curiosity and academic well-being linked by an indirect path (P<0.001).
Conclusions: Overall, the modified final model exhibited a good fit. Accordingly, this model can be considered a useful step in identifying factors that influence academic well-being of adolescents with physical and motor disabilities.


Volume 9, Issue 4 (No. 4 (Tome 46), (Articles in Persian) 2018)
Abstract

The study aimed at developing a hypothesized model and questionnaire of language glocalization for the first time to accomplish systematic data generation and collection of the teachers’ perceptions regarding the glocalization of language education (LEG) in Iran. Hence, a model was initially hypothesized and the researchers went through scientific phases to generate a reliable and validated LEG questionnaire to test the model. Face validity, content validity and construct validity of the questionnaire were investigated. For exploratory factor analysis, the criterions for the data factorability being met, the researchers ran factor analysis employing Principle Components Analysis (PCA) method resulting in identification of five factors. Cronbach’s Alpha coefficient was used to measure the questionnaire internal consistency. The Cronbach’s Alpha results indicated that the internal consistency was 0.96 for the whole questionnaire, and 0.89, 0.92, 0.88, 0.89, and 0.87 respectively for the five components of LEG as the subscales in the questionnaire. After running exploratory factor analysis, to check whether the questionnaire data fits the hypothesized model of LEG introduced at the beginning of the study, a confirmatory factor analysis was done. Then, the final version of the questionnaire was administered to 270 language teachers to gather the data to feed it to the model to see the extent to which the model fit the data. The results of the study revealed that although the model has been the first one of its kind, it displayed a reasonable degree of reliability and validity as confirmed by the statistical procedures. The developed and validated model and the questionnaire of this study can have many practical applications for Iranian EFL teachers as well as future researches in other contexts.
 

Volume 12, Issue 1 (3-2012)
Abstract

The flow at a channel bifurcation is turbulent, highly three-dimensional (3D) and has many complex features. There is transverse motion accompanying the main flow and an extensive separation zone that develops in the branch channel. There are two complex flow regions along the intake channel: one is the separation zone and the other is the region in which helical motion of water particles forms. This separation occurs because the flow entering the branch channel has considerable momentum in the direction of the main channel flow. This zone causes hydraulic and sedimentation problems that must be known before designing the system. This necessitates a deeper insight into the flow patterns and shear stress distributions near the solid boundaries. In this research, 3D flow patterns at lateral diversion were investigated experimentally and numerically. The experimental investigation was carried out at a T-junction, formed by two channels with rectangular cross-sections. The width of lateral intake to the main channel was 0.4. 3D velocity measurements were obtained using Acoustic Doppler Velocimeter at junction region for 11%, 16% and 21% discharge ratios. Fluent mathematical model was then used to investigate the dividing open-channel flow characteristics. Turbulence was modeled by Two Equation (k-ε, k-ω) and Reynolds Stress (RSM) turbulence models. The predicted flow characteristics were validated using experimental data and the proper model was selected for hydrodynamic and parametric studies. Within the main channel, good agreement was obtained between all models prediction and the experimental measurements, but within the lateral channel, the RSM predictions were in better agreement with the measured data, and k-ω predictions was better than those of k-ε. The comparison of experimental and numerical streamlines at different elevations showed that the selected model is capable to simulate the most important features of flow at diversions. The study of the velocity contours at different elevations showed that the velocity magnitude decreases at main channel, just downstream corner of lateral intake at the near bed levels and this causes the sedimentation in movable beds. The results showed that the width of separation zone at lateral intake will decrease and the distance of dividing stream surface from left bank of the main channel will increase by increasing of the discharge ratio. Investigation of the flow pattern at the entrance of the lateral intake showed that the secondary flow will form at this section. The dimension of the secondary flow at near bed elevation will increase by increasing of the discharge ratio and this causes entering of more bed load into the lateral channel.

Volume 13, Issue 2 (5-2013)
Abstract

Abstract: In this paper the experimental study of the flow pattern around a round wall jet has been carried out to investigate the effect of the bed roughness on the turbulence characteristics, including Reynolds stress and turbulence intensities. Measurements were conducted using the three-dimensional velocimeter, ADV and time series of the velocity components are used to investigate the variation of the turbulent flow parameters along the measuring domain. The results showed that by increasing the bed roughness, the streamwise and vertical turbulence intensities increase by downstream distance and for a specific bed roughness the streamwise turbulence intensity is higher than the vertical one. Furthermore, by going downstream from the jet entrance the bed shear stress reduces and by increasing the bed roughness, the bed shear stress has an increasing trend along the jet centerline. Location of the maximum bed shear stress does not change by changing the bed roughness.

Volume 16, Issue 1 (3-2016)
Abstract

In this paper, the flow field between two straight groynes in shallow wide open channel has been measured using Particle Image Velocimetry method. Groynes with 25cm length, 5cm width and 7cm height with two aspect ratios of 1 and 2 have been located in the fully developed zone of a 18m length flume and velocity measurements carried out in order to study the circulating flow, structure of the mixing layer and downstream separation zone. Image processing is conducted using GPIV software and Westerweel and Brevis methods are used for filtering of the measured velocity fields. Results are presented in form of time averaged values, turbulence intensities and Reynolds stresses at various zones of the groyne field. Results showed that due to the flow shallowness, most of the turbulent structures are two dimensional. Development of a back flow from downstream zone to the groyne field enhances the complexity of the mixing layer and mas exchange phenomenon compared to the groyne series configuration. In this paper, the flow field between two straight groynes in shallow wide open channel has been measured using Particle Image Velocimetry method. Groynes with 25cm length, 5cm width and 7cm height with two aspect ratios of 1 and 2 have been located in the fully developed zone of a 18m length flume and velocity measurements carried out in order to study the circulating flow, structure of the mixing layer and downstream separation zone. Image processing is conducted using GPIV software and Westerweel and Brevis methods are used for filtering of the measured velocity fields. Results are presented in form of time averaged values, turbulence intensities and Reynolds stresses at various zones of the groyne field. Results showed that due to the flow shallowness, most of the turbulent structures are two dimensional. Development of a back flow from downstream zone to the groyne field enhances the complexity of the mixing layer and mas exchange phenomenon compared to the groyne series configuration. In this paper, the flow field between two straight groynes in shallow wide open channel has been measured using Particle Image Velocimetry method. Groynes with 25cm length, 5cm width and 7cm height with two aspect ratios of 1 and 2 have been located in the fully developed zone of a 18m length flume and velocity measurements carried out in order to study the circulating flow, structure of the mixing layer and downstream separation zone. Image processing is conducted using GPIV software and Westerweel and Brevis methods are used for filtering of the measured velocity fields. Results are presented in form of time averaged values, turbulence intensities and Reynolds stresses at various zones of the groyne field. Results showed that due to the flow shallowness, most of the turbulent structures are two dimensional. Development of a back flow from downstream zone to the groyne field enhances the complexity of the mixing layer and mas exchange phenomenon compared to the groyne series configuration. enhances the complexity of the mixing layer and mas exchange phenomenon compared to the groyne series configuration.

Volume 17, Issue 3 (9-2017)
Abstract

In this paper, the dam break phenomena has been simulated in curved rivers using 3D numerical model, Flow-3D. It utilizes the finite volume scheme for structured meshes was used for solving the unsteady Reynolds-averaged Navier-Stokes equations in conjunction with the RNG k-ε closure model. In the utilized software, the Fractional Area/Volume Obstacle Representation (FAVOR) method is used to inspect the geometry in the finite volume mesh. FAVOR appoints the obstacles in a calculation cell with a factional value between 0 to 1 as obstacle fills in the cell. Fluid surface shape is illustrated by volume-of-fluid (VOF) function F(x,y,z,t). With the VOF method, grid cells are classified as empty, full, or partially filled with fluid. Cells are allocated in the fluid fraction varying from zero to one, depending on fluid quantity. The pressure and velocity are coupled implicitly by using the time-advanced pressures and time-advanced velocities in the momentum and continuity equations, respectively. FLOW3D solves these semi-implicit equations iteratively using relaxation techniques. In this paper the GMRES technique has been used as pressure implicit solver. A flux surface is a diagnostic feature in FLOW-3D for computing fluid flow rates. It can be used to obtain time-dependent information about the flow in different parts of the domain. A typical flux surface is a 100% porous baffle with no flow losses, so it does not affect the flow in any way. This feature gives the opportunity to determine the flood hydrograph at various stations downstream of the dam. Effects of curve angle and radious of curvature on the flood wave propagation and unsteady flow features along the curved reach, downstream of the dam has been investigated. Results showed that at the initial instants of the dam break in the straight channel, due to the effects of the dynamic wave, flood hydrographs at the dam location and at a distance downstream of the dam have local peak values, while in the curved chnnel cases, the flood wave becomes unstable immediately after the dam break and the local peak occures just at the dam section. The curved reach decelerate the flood wave propagation compared to the straight channel. Effect of channel curvature on the movement of the flood wave along the inner bank is higher than the outer bank and also the centerline of the curved channel. By decreasing the central radious of the bend, slope of the rising limb of the hydrograph and also the peak discharge, attenuates. Furthermore, the peak discharge time reduces. Unlike to effects of the curvature of the bend, increasing the bend angle does not affect the peak discharge. Changing the bend curvature and curve angle has no effect on the falling limb of the flood hydrograph at various stations downstream of the dam.

Volume 17, Issue 4 (1-2014)
Abstract

After the industrial economy span that caused many changes in the human life and the human systems, now we are facing a new era in the electronic revolution. One of the symbols of this electronic revolution is Mobile Commerce. Nowadays, this new style of trading has been used in many parts of the globe especially, in the developing countries. Now the fundamental question is how to design and explain the business development model. To solve this issue, the present exploratory study has been conducted, with the scoring and weighting the extracted factors and making items for them, by the Delphi panel of experts (during four rounds), the researcher found three dimensions (technological, social and personality) and twelve new variables. These variables formed the conceptual model of Mobile Commerce. The conceptual model has been examined in the Iranian Virtual Society with designed questionnaire and using AMOS software. The collected data were analyzed using Structural Equation Modeling. For this purpose, initially the structural relationships have been tested by using Confirmatory Factor Analysis, then with a Path Analysis approach the hypotheses have been examined. At the end this research, with the future studies approach and adding the time dimension to the three dimensions, makes the model more dynamic.
Dr Hossein Raghfar, Dr Esmaeel Safarzadeh, Fahime Aliakbari Salami,
Volume 18, Issue 1 (Spring 2018 2018)
Abstract

Inequality is a major problem in the developing countries.  It is also an acute and critical subject in Iran compared with other developing economies.  Besides the existence of inequality, its social effects have made its explanation crucial. The aim of this research is to measure the multidimensional inequality in urban areas of Iran during three presidential periods: 1989 -1997, 1997-2005 and 2005-2013. Income, health and education are the dimensions under study. This research uses household expenditure-income survey data for the selected periods. Gini coefficient is measured for one-dimensional inequalities in terms of each dimension, generalized entropy is computed for the beginning and ending years of each period, and the multidimensional inequality is measured by using the Bourguignon index. Results indicate that the Gini coefficient decreased in terms of income dimension in all three periods while it increased in terms of health dimension during all periods. In education dimension, Gini index increased in the second period and decreased in other periods. The measured entropy indices are of some fluctuations in all periods for all dimensions. The measured multidimensional inequality index provides a wide range of results for different substitution and inequality aversion parameters. In general, this index indicates worse conditions in the second period compared with other periods.

Volume 19, Issue 5 (12-2019)
Abstract

In this paper hydraulics and flow structure over the rectangular piano key weirs with different heights have been studied experimentally and numerically and effects of different fillet shapes on hydraulic performance are investigated. Experiments are conducted in a one meter width flume. Models of the tested weirs are made from PVC Plates in 3 different heights and with the same L/W ratios equal to 5. Discharge coefficient curve for wide range of heads over height ratio for 3 different weir heights are determined and effect of triangular, half round and oval fillets on increasing of discharge coefficient are investigated. In this research, the chosen range for ratio of head over height is in good agreement with ratio which has been used to design of prototype weirs. Large triangular and oval shaped fillets have significant effects on improvement of performance of the piano key weirs. Main effect of fillets is more uniformly distribution of the flow streamlines over the downstream part of the side crest. In second part of this paper, one and half-key piano key weirs with oval noses and without any nose (net) have been numerically modeled using Flow-3D model. Discharge coefficients of one of the numerically simulated rectangular models is compared with derived discharge coefficient curve from physical model. Convergence of inflow and outflow of numerical model has been controlled. Satisfactory correspondence presents between the experimental and numerical studies. Discharge distribution over the crest of the normal PKW and the weir equipped with oval fillet are compared. Result showed that due to uniformly distribution of the streamlines, the fillet notably increases flow rate at the downstream part of the side crest. Results of numerical simulations are exported to Tecplot software, in order to visualize the flow streamlines at different parts of the studied weirs. The weir with oval fillet affects the flow streamlines in three positions: the near bead streamlines of the weir with oval fillet, have less lateral diversion when they reach beneath the overhang of the outlet keys. In other word, streamlines pass this region more smoothly rather than normal PKW. As a result, the fillet decreases the local head loss, when the flow enters the inlet keys. Streamlines of the mid depth level show less contraction at the entrance and middle of the inlet keys. Consequently, lower velocity of the flow along the inlet keys, helps to more evacuation of the flow from side crests. Finally, streamlines release more uniformly from downstream part of the side crest. These phenomena results low submergence level at the middle of the outlet keys. The outlet keys are the brake of nonlinear weirs. By decreasing the submergence level of the outlet keys, flow from the side crests discharge more freely from inlet to the outlet keys.   
Mrs. Mandana Atefi, Dr Hossein Raghfar, Dr Mir Hossein Mousavi, Dr Esmaeil Safarzadeh,
Volume 20, Issue 2 (summer 2020 2020)
Abstract

This study aims to investigate the percentage of households facing catastrophic health expenditure and the impoverishment index before and after the implementation of the Health System Reform Plan (HSRP) in rural and urban areas of Iran. This research is based on statistical inference, life-cycle theory and pseudo-panel approach, which uses household income-expenditure survey data during 2014-2017. Using the STATA-SE13 and Excel softwares, households were categorized in 10 age groups of households’ heads born between 1944 and 1993 within five-year intervals. The indexes were calculated in weighted and non-weighted cases for total households, and households having health expenditure. After the implementation of HSRP, the percentage of households with catastrophic health expenditure remained relatively unchanged and impoverishment index decreased slightly. In 2015, both rural and urban households having health expenditure in non-weighted case were faced to the least catastrophic expenditure and the least impoverishment index. Totally, rural and urban areas with elderly household-heads experienced the highest catastrophic health expenditure and impoverishment rate.
Mr. Abdolreza Iesvand Heidari, Dr Mir Hossein Mousavi, Dr Saleh Ghavidel, Esmaeel Safarzadeh,
Volume 22, Issue 3 (Autumn 2022 2022)
Abstract

The purpose of this article is to investigate the effects of macroeconomic variables such as exchange rate, interest rate, economic growth and real money residual growth on the financial stability in the Iranian insurance industry. For this purpose, Markov switching method is used. The ability to account for changes in the relationship between macroeconomic variables and the financial stability of the insurance industry over time is one of the most important features of the Markov switching method. The period under study is from the first quarter of 2005 to the fourth quarter of 2015. The results show that the effects of macroeconomic variables during the first regime (including the first quarter of 2005 to the third quarter of 2008) and the second regime (including the fourth quarter of 2008 to the fourth quarter of 2015) on financial stability of the insurance industry are different. So that the effects of exchange rate, interest rate and economic growth on the financial stability of the insurance industry in the first regime are the opposite of those of the second regime. This is while the growth of the real balance of money has a direct link to the financial stability of the insurance industry in each round of the regime, but in the second regime, which is a recessionary regime, its effect on financial stability is insignificant. Also, the findings show that the stability of the first regime is more than the second regime, so that if the insurance industry is in regime one in the previous period, with a probability of 94% it will be again in regime one.


Volume 23, Issue 0 (Special issue 2021)
Abstract

Coronavirus disease 2019 (COVID-19) is a virally-induced pneumonia caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). This is the third disease-causing coronavirus after severe acute respiratory syndrome coronavirus (SARS-CoV) and the middle east respiratory syndrome coronavirus (MERS-CoV) which has been known in the human population in the 21st century. To this date (20th of Mehr, 1399), more than thirty-four million people have been infected by this virus and more than a million have lost their lives because of it which further signifies the importance of COVID-19 prevention and treatment. In this review article, we first take a look at the history of the famous coronaviruses and then introduce the genetic and pathophysiology of SARS-CoV-2 in a detailed manner. After discussing the related clinical manifestations, we shed a light on the treatments that have been assessed to this date. In the end, we will briefly discuss the vaccines that are currency being developed and highlight their success rate, so far. It is delightful to assert that out own research team is currently developing an oral and/or respiratory vaccine against SARS-CoV-2 which is composed of spike-surface decorated chitosan nanoparticles.

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