فهرست مطالب مهدی خزایی

Research Issue:

 With the victory of the Islamic Revolution and its goal in achieving comprehensive development, nuclear energy became the focus of the men's government. Enmity with the Islamic Revolution and opposition to the West with its development caused Iran's goal of peaceful use of nuclear energy to turn into an international. Accordingly, the purpose of this study is to investigate the legal consequences of Borjam.

The present study seeks to investigate the legal consequences of JCPOA by descriptive-analytical method, which is used by libraries with the method of deleting files from law book sources as well as the use of Internet resources.

In this study, the historical course of the nuclear negotiations from the 2000s to the Vienna Agreement, the legal opportunities and threats of the UN Security Council, the legal weakness of the UN Security Council were discussed. Some believe that after reaching a nuclear agreement or a UN Security Council, due to the form of the document and citing the intentions of the parties and explicitly the text, only the executive document contains some voluntary actions by both parties and therefore, it can not be A treaty, agreement, treaty or international agreement.

The great interest of the followers of different Islamic denominations in Ahl al-Bayt (the Prophet's household) has not prevented the emergence of differences regarding the determination of their examples and place among Muslim scholars. These differences, which have an ideological and political basis, have been effective in the field of Islamic historiography. Despite the fact that most Muslim historians deal with the issue of Ahl al-Bayt, the historical texts differ from each other in terms of definition and scope of examples, preemption in compilation, the number of works, as well as the method and goals of raising the issue. We believe that Shiite historians, in addition to being pioneers in writing about this topic, have also produced more works. While the followers of the Sunni denominations have paid more attention to the personal and moral virtues of Ahl al-Bayt, the Shia historians, especially the Imamis, in their historical texts, in addition to expressing the personal and moral virtues, have highlighted their social status and the issue of Imamate and leadership. The use of theological foundations by Shiite historians in the historiography of Ahl al-Bayt and the focus of Sunnis on historical reports are other distinctions in this regard, which show that the compilations on this issue were influenced by the ideological and political conditions of different geographical regions in the Islamic society.

SIP is considered as a signaling protocol for IP multimedia subsystem (IMS) and IMS is introduced as the next generation networking platform. Unlike positive features such as text-based, IP-based, data-independent, support mobility and end-to-end, SIP lacks a proper overload control mechanism. Hence, this challenge will cause the widespread users of next generation networks to loss quality of service. IMS is a complex network consisting of subsystems, interacting with each other. As a result, multi-agent systems can be a useful tool to solve the IMS overload. Therefore, each IMS server is considered as an intelligent agent with learning and negotiation ability with other agents while maintaining autonomy therefore, the overload is eliminated by communication and knowledge transferred between agents. In this paper, multi-agent system and their properties presents a hop-by-hop elimination-based method which simulation results show performance improvement compared to known methods.

The present study investigated the relationship between identity base and personality traits with moral education of second grade elementary students in Delfan city. To investigate this relationship, a descriptive research design has been used. The study population was preschool students and educators. The tests were performed on a sample of 120 people. The identity database was measured by the objective extended test of the identity-review second database and each of the subjects was placed in one of the access, suspension, obstruction and dispersion databases. Personality traits were measured by 16-factor Cattell personality test and subjects in each of Cattell factors were divided into two groups: high (scores 8-9-10) and low groups (scores 3-2-1). The results of data analysis showed that there is a significant correlation between some personality traits and identity bases with moral education and individuals in the upper and lower groups of Cattell personality factors showed a significant difference in the scores of identity bases. In this study, a significant relationship was also found between identity databases and variables of birth order, marital status and field of study of educators.

A firm’s tendency to supply and demand an optimal amount of trade credit stems from the fact that deviation from this level can negatively affect the firm value. Firms are constantly looking for an optimal level of trade credit; however, the associated costs slow down the adjustment process. Nevertheless, there are some factors that can speed up the achievement of an optimal trade credit. This study investigated the effect of operational risk and firm’s market power on the speed of achieving the optimal trade credit ratio in 128 listed companies in Tehran Stock Exchange (TSE) for the period of 2005-2020. Panel data and system GMM estimators were used for this purpose. The results showed that the sample firms reduced around 65% (39%) of the gap between the supply (demand) of the actual trade credit and the optimal level every year. In other words, they could correct half of the deviation of the supply (demand) of trade credit within about 8 months (17 months). In addition, the research findings indicated that an increase in the operational risk and firm’s market power enhanced the speed of achieving the optimal level of trade credit. The supplementary analyses confirmed the main research findings and were consistent with the trade-off theory.

Having carcinogenic and toxic effects, aromatic hydrocarbons cause serious damage to the environment and living organisms. These compounds are mainly discharged into the soil. For the remediation of contaminated soils, biological methods utilizing the efficient microorganisms isolated from the oil-contaminated soils as well as resistant plants are preferred. The aim of this study was to assess the effect of Conocarpus erectus and Pseudomonas aeruginosa on the removal efficiency of polycyclic aromatic hydrocarbons (PAHs) from contaminated and saline soils of the salt separation pond of a desalination unit during 275 days under non-laboratory condition. The study was conducted in a factorial experiment with two factors based on completely randomized design with three replications. The factors used in this experiment included four treatment types (plant, bacteria, plant-bacteria cultivated in the soil, and soil with no plant and bacteria (control)) and the concentration of contaminant (Bangestan crude oil) with 5 levels (0, 0.5, 1, 2.5, and 5 wt%). As hydrocarbon concentrations increased at all five levels, the percentage of PAHs removal, the dry weight of roots and shoots, and chlorophyll contents decreased. At 0 and 1 % concentrations, the highest percentages of removal were obtained as 99.43, 59.89, and 57.01 for bacteria-plant treatment and separate bacterial and plant treatments, respectively (p≤0.05). The plant and the bacteria showed almost equal efficiency in the removal of oil hydrocarbons (p≤0.05). Bacterial treatments led to increased chlorophyll content as well as higher dry weight of roots and shoots compared with the treatments without bacteria (p≤0.05). Results indicated that individual treatments of plant and bacteria had a positive effect on the decomposition rate of PAHs. However, the rate was more positively influenced by the synergistic activity of the bacteria and plants (p≤0.05).

Water vapor is the dominant greenhouse gas in the Earth’s atmosphere and, at the same time, highly variable in the atmosphere. Observations of its spatial and temporal variations is a major objective of climate. It is important in several major areas in the atmospheric sciences, on scales from turbulence to synoptic-scale systems, and including cloud formation and maintenance, radiation and climate. The intent of this paper is to demonstrate the ability of MODIS PWV products for use in monthly and daily variability of climatological scales over Iran. Therefore, the results are presented in two sections. The first section compares the long term (2003-2015) Monthly mean MODIS Level 3 and ERA-Interim PWV data sets. The second section validates the level 2 MODIS PWV products by Radiosonde daily data. For a better comparison of MODIS level 2 PWV products with Radiosonde data, we used data from 10 Radiosonde stations over Iran. We consider the sky conditions (cloudiness and visibility) in our comparison. There are no microwave radiometers (MWR) and Global Positioning System (GPS) sites in Iran hence, in the absence of these data, we used the measurements of Radiosonde and ERA-Interim as reference data for the comparison of the MODIS PWV estimates. These data were obtained at monthly and daily scales. In the first section, long-term (2003- 2015) spatial and temporal characteristics of monthly mean PWV are investigated over Iran. For this, Level-3 MODIS terra (MOD08_M3) products and ERA-Interim data were obtained with the 1-degree resolution for Iran. In the second section, January (as a month with low values of PWV and unstable atmosphere) of 2004 and July (as a month with high values of PWV and Stable atmosphere) of 2008 were selected for comparison of MODIS daily (MOD05-L2) PWV product with Radiosonde data for 10 Radiosonde stations in Iran. The average annual MODIS and ERA-Interim PWV data are 12.248 and 12.243 mm, respectively.These values are very close to each other. These values are also close to those derived by Asakereh et al. (2015) from NCEP data reanalysis (about 14.3 mm). Also, Ferencz and Pongra (2008) concluded that the ERA-Interim and the MODIS PWV fields are very similar.The maximum and minimum values of PWV for both data sets is observed during July and January, respectively. Tuller (1968) indicated that February and July are the months of highest and lowest precipitable water at most stations. At some, August replaces July, and at a smaller number, January replaces February. Also, our result is the same with the study of Maghrabi & Dajani, (2014) over Saudi Arabia. They reported that the lowest PWV values were in December and January, whereas the highest values were in June and July. They pointed that during warm periods, increases in the temperature and height of constant pressure levels result in an increased capacity for water vapor of the air mass, keeping it away from the saturation point and consequently preserving high PWV values. In contrast, in cold periods, the decrease in the height of constant- pressure levels, reduce the capacity for water vapor of the air mass and facilitates the condensation process, resulting in a decrease in the amount of PWV. The topography is a key factor in the spatial distribution of PWV. PWV from both data sets has a significant negative relationship with the distribution of topography in all months. This means that the concentration of PWV is high in the highland regions and vice versa. During January 2004, the ranges of errors are in the best case 5.53 mm (Tabriz) and in the worst case (Ahwaz) 16.02 mm. In all stations, the coefficient of determinations are negligible. While in the suitable weather condition, RMSE is decreased in all stations. During July of 2008 at many stations such as Zahedan, Kerman and Esfahan cloud cover and visibility condition have been appropriate, while in Bandar Abbas in all days the visibility was poor (less than 5 KM). It seems that the cloud cover and visibility conditions result in the high coefficient of determinations in Esfahan, Kerman and Zahedan (77, 80 and 66%, respectively) and with high error in Bandar Abbas station. Annual average MODIS PWV and ERA-Interim are close to each other (12.24), in addition, MODIS has a higher negative correlation coefficient with topography compared to ERA-Interim PWV data. This suggests that MODIS level-3 monthly PWV data are valuable for the monthly long-term climatology of PWV over Iran. In daily scale, a comparison of MODIS and radiosonde PWV data in different atmospheric conditions are significantly different. During clear days with appropriate visibility (despite the time lag between two data sets) values of R2 is higher compared to cloudy days with poor visibility. Hence, accuracy of the MODIS PWV data over Iran is strongly dependent on weather conditions.

Comparability is among the key qualitative characteristics of accounting information, which can be affected by various factors like management motivation and earnings management. On the other hand, ownership structure is a corporate governance mechanism that can affect different aspects of an enterprise. The purpose of this study is to investigate the moderating effect of ownership structure on the relation between accounting comparability and earnings management. The population of this research includes all listed companies on Tehran Stock Exchange. The sample consists of 120 listed manufacturing firms from the period 2005 to 2016. This research uses panel data and multivariate regression methods (with controlled effects of years and industries) for data analysis and hypothesis testing. The empirical results from testing the first hypothesis imply a significant negative relation between comparability and earnings management. The findings from testing the second hypothesis show that any increase of institutional ownership may cushion the negative impact of earnings management on financial statement comparability. The results from testing the third hypothesis cannot find any significant impact of ownership concentration on the relation between financial statement comparability and earnings management.

Evapotranspiration is one of the critical parameters in the planning and management of water resources, especially in the agricultural sector. In this study have been discussed to review the reference evapotranspiration from the perspective of main factors its aggravating, with an emphasis on pressure systems in the warm season over the period 2014 1985 in the South West of the country. For this purpose at first, reference evapotranspiration calculated and then correlation values with the parameters of temperature, radiation, humidity and wind were calculated and finally to review of pressure systems, the average data of sea level pressure, zonal and meridional wind from the June to August in the period of 1985 - 2014 provided and maps were drawn. The results show that the correlation maximum of the reference evapotranspiration with wind parameter obtained So that in more than half of the studied stations, correlation coefficient has been more than 0.90 and almost at all stations (except station in Bushehr and coastal Bushehr) was more than 0.80. Among the parameters, moisture in many stations has had negative correlation with evapotranspiration. The radiation parameter than temperature parameter the more positive correlation has experienced in most stations. Review of pressure systems summer at sea level pressure indicates that the interaction of the western tongues monsoon low pressure system and eastern tongues Azores subtropical high pressure on the East Mediterranean sea is as the main factor of pressure gradient on the Middle East, including the South West of the country. That resulted northwest prevailing wind flow from the eastern Mediterranean conduct to the study area. As well as the prevailing wind flow in the study area from June to August, has been the Northwest. Cause of Strengthen and increase the wind speed and the result has been an increase in evapotranspiration, which would be a serious risk, especially in enhancing crop water requirement is due to the limited available water.

This study investigates the subtropical anticyclones and summer monsoons of the north hemisphere in the 500 hPa level, effective on Iran in a 38-year period (1975-2012). For this purpose, the data of geopotential heights of 500 hPa at 12 UTC with a spatial resolution of 2 by 2 degrees of the (NCEP/NCAR) were used. Results show that three independent patterns (Azores anticyclone, Saudi anticyclone and North West Africa anticyclone) and four combinatory patterns derived from the independent patterns have controlled the atmosphere of 500 hPa level of Iran. In most cases, the maximum in geopotential heights in above-mentioned anticyclone centers reach to more than 5920 geopotential meters, but often the tongue of these anticyclones control the atmosphere of 500 hPa levels of Iran with the geopotential height of 5880 to 5900 meters. In contrast, at this pressure level, the large-scale monsoon system is very weak and the maximum geopotential height of this system is about 5840 meters. The extent and intensity of the monsoon system has been reduced so that its tongues do not affect the 500 hPa level of Iran at any time. Given that the main factor in the development of large-scale monsoon system is the surface heating (bottom-up formation) and the main factor in the development of subtropical anticyclone is descending of atmospheric dynamics, the main reason for the development of summertime subtropical dynamic anticyclone should be a very strong and unit agent, something other than the summer monsoons.

The purpose of this study is to identify and investigate the synoptic systems that led to the extensive and destructive flood events in the west and southwest of the country on March 31 and April 1, 2019.

In order to study the synoptic conditions in coincided with the event of heavy rainfall leading to the floods, in addition to using NOAA18 satellite images, sea level pressure data, sea level specific humidity, geopotential height and omega at pressure level 850, 700 and 500 hPa, Relative humidity pressure  at 700 hPa, U and V component from pressure 1000 to 200 hPa with a resolution of 2.5 ° to 2.5° latitude from the National Center for Environmental Prediction and the National Center for Atmospheric Research (NCEP / NCAR) Received and the maps were plotted.

Existence of a deep cyclone at sea level pressure to 500 hPa pressure from eastern Mediterranean to western of Iran and also the establishment of a subtropical jet stream with meridian direction (southwest - northeast) in the southwest and west of the country and finally the intense vertical shear of horizontal wind from sea level pressure to 200 hPa in the study area, It is known as the main factors of cause of instability in the west and southwest of the country. existence Specific humidity of 14 to 18 g / kg at sea level pressure and relative humidity of 95 to 100% at a pressure of 700 hPa have also been identified as suitable moisture conditions in the study area.

The results of this study show that on March 31 and April 1, 2019, the atmosphere of the western and southwestern regions of the country in all depths of the troposphere layer experienced severe instability due to the establishment eastern part of a deep cyclone. Above the cyclone mentioned above, located meridional flows of subtropical jet stream which has intensificated the instability to the depth of the tropospheric layer. Also moisture advection from the western Arabian Sea, the Red Sea and the Persian Gulf has caused form cells from thick convective clouds throughout the west and southwest of the country. The heavy rains resulting from these convective clouds have caused severe and extensive floods in this area of the country.

Weapons of mass destruction and their destructive effects have always been the focus of lawyers' efforts to create legal barriers to non-proliferation, as the consequences of these weapons are far from universal in the international community. This article, while addressing the nature of the international agreement of the Joint Comprehensive Plan of Action, which is called the "JCPOA", (as is called "Barjam" in Persian) seeks to examine the role of non-proliferation of WMDs in international law. In this paper, after expanding the conceptual space of the "JCPOA ", its importance and role in the non-proliferation of WMDs are discussed. The research method used in this article is descriptive-analytical and data collection has been done in the form of libraries. The findings of this study suggest that JCPOA, through its commitment to and implementation of the International Atomic Energy Agency's Additional Protocol and Safeguards, and the memoranda and transparency measures set out in the text of the Vienna Agreement, reduce international arms competition and non-proliferation. The ruling affects the non-proliferation of weapons of mass destruction.

Despite the main role of cranes in advancing construction operations, however, accidents and occupational injuries resulting from their activities have become a critical issue. Recent evidence suggests that the cause of these problems may be associated with the absence of design of the interior space of the crane cabin, and the tasks of the operators, based on ergonomic principles. This study was conducted to assess the ergonomic risk of the tower crane operator’s activities and redesigning the dimensions and interior space of these cranes, based on the anthropometric dimensions of Iranian operators.

In this descriptive cross-sectional study, 30 male tower crane operators working on three major construction projects in Tehran were investigated. Initially, a multi-step approach was applied to define the problem, including: observing the working statuses, interviewing operators, Nordic Musculoskeletal Disorder Questionnaire, and rapid upper limb assessment (RULA) method. Then, using anthropometric data, the dimensions and interior space of the crane chamber were redesigned.

The results of the rapid upper limb assessment method showed that the activities of tower crane operators were at high and very high-risk levels. Also, 85% and 38.5% of these people reported pain and discomfort in one of the nine areas of their body in the last 12 months and 7 days, respectively. In this study, the dimensions of the interior space of the redesigned tower crane cabin were obtained 160.8×144.1×199.7.

Based on the results of the study, it can be concluded that the current interior design of the tower crane cabin does not fulfill the needs of the operators. Hence, redesigning it appears essential to enhance human-machine compatibility, improve safety and productivity, and prevent musculoskeletal disorders (MSD).

</strong></span> Although suction is an important nursing intervention in neonates under ventilation, it can lead to complications such as pain, respiratory distress, hypoxemia, bronchospasm and hospital infection. The purpose of this study was to determine the relationship between pain score and its effective indices in neonatal endotracheal open suction under ventilator in the neonatal intensive care unit of Hamadan hospitals.

</strong></span> This descriptive correlational study was performed on 120 preterm infants under ventilation in Neonatal intensive care unit of Hamadan hospitals. First, 5 minutes before the patient suction, the respiratory rate and oxygen saturation of the neonatal arterial blood were recorded by the researcher in three shifts based on the findings of the direct monitoring of the infant. During and 5 minutes after suction, the respiratory rate and oxygen saturation index was re-recorded. Data were analyzed using descriptive and regression tests.

</strong></span> According on the results of the applied linear regression model, there was a statistically significant relationship between the pressure of the suction device, the duration of suction and the number of suctions with the pain score(P =0.000) but there was no statistically significant relationship between the size of the suction catheter and the pain score (P =0.235).

</strong></span> Endotracheal open suction in premature infants can greatly affect the number of respiration and oxygen saturation in the arterial blood and increase the pain score in these infants.</div>

Undesirable experience as “moral distress” is one of the major issues faced by nurses when making moral decisions. The spiritual dimension is one of the dimensions that influences their moral distress; therefore, this study was conducted with the aim of determining the relationship between spiritual health and the moral distress of nurses working in the emergency departments. In this descriptive-analytic study, 140 nurses working in the emergency departments of the educational and medical centers of Hamedan participated by census sampling. Data were collected through a three-part questionnaire, including demographic information, Paloutzian and Ellison spiritual health questionnaires and Corly moral distress questionnaire. The data was analyzed by Chi-square test and Pearson correlation coefficients using SPSS software, version 16.</strong> The mean age of participants was 31.9 ± 7.31 years. The spiritual health score and moral distress of most nurses were moderate. A negative and significant correlation was observed between spiritual health and the severity of nurseschr('39') moral distress, (r = -0.200, p = 0.05), meaning that the higher the nursechr('39')s spiritual health score, the lower their moral distress. The results indicate that spiritual health is an effective parameter in reducing moral distress in nurses, so it is suggested to pay attention to spiritual’s dimension in promotion of nurseschr('39') health.

The proximity of the two lakes of Urumia and Van and the intensification of changes in the level of water level in Lake Urmia over lake Van has caused that in many studies, assuming the similarity of the natural features of two lakes, the human factor as the most important factor in the reduction event The water level of Lake Urmia is considered. In this study, the natural disparities between the two above mentioned lakes as the most important factor in the survival and decline of the two lakes of Urumia and Van in the era of climate change have been attempted. For this purpose, we first examined the status of the azure zone of the two above mentioned lakes and then, to study the temperature and relative humidity of the two lakes, use of the ECMWF database by the seasons of the year during a 39-year statistical period (1979-2017) Has been. Studies show that in different seasons, the temperature of the air at the lake level is 2 to 4 degrees less than Lake Urmia and its relative humidity, except for winter, is 2 to 6 percent higher. There are also many differences in terms of depth, water volume, bed slope, rainfall, evaporation, runoff and topography around two lakes, so that the average depth of the lake is about 29 times the average depth of Lake Urmia and the average volume of lake water The tub is more than 100 times the volume of Lake Urmia water.

With regard to high prevalence of musculoskeletal disorders in the construction industry workers, the aim of this study was to investigate the prevalence of musculoskeletal disorders and their relevant risk factors in workers of a construction factory.

This descriptive-analytical cross-sectional study was conducted in 2019. In this regard, 150 workers were selected from a construction factory located in Tehran City, Iran. The census sampling method was applied in the area under study. The data gathering tool were Cornell questionnaire and WERA ergonomic risk assessment method. The questionnaires were completed while the workers' postures were assessed in their work stations. Data were analyzed applying suitable descriptive and analytical tests in SPSS software version 22.

The analysis of questionnaires showed that the workers' lower back had the highest average score of pain. The wrist, knee, and shoulder had the highest pain average scores, respectively. The result of ergonomic assessment by WERA method indicated that the lower back had the highest risk score. Similarly, WERA assessment score was significantly related to the type of job (p-value < 0.001). Among the understudy occupations, masonry, concrete testing, and welding had the highest risk scores, respectively.

The most ergonomic risk factors in activities of the extensive occupational groups are associated with multiple occupational tasks that endanger workers for serious risk factors in the lumbar and knee areas. Therefore, implementation of ergonomic interventions is necessary for improving the working conditions of construction occupations.

One of the most devastating phenomena of meteorology which varies extensively in spatial and temporal extent and manifests itself at various scales, is thunderstorms. The purpose of this study was to identify and analyze such destructive storms over a period of 25 years (1986-2010) at the synoptic station of Kermanshah. The data used in this research includes daily rainfall data and codes related to meteorological phenomena, dry temperature, dew point, relative humidity, wind direction and wind speed for calculation of instability indices, geopotential height parameters, specific humidity, vertical velocity, and zonal and meridional components. The results showed that during the statistical period of the study, three extreme thunderstorms occurred in the study area during the statistical period of 25 years. The study of instability indices indicates that these indices are in the strong and suitable category for the occurrence of thunderstorm phenomenon; in addition, the dynamics of the atmosphere at the time of the occurrence of this phenomenon indicates the presence of a very deep trough and negative abnormalities in the west of the studied region and positioning of the left half of the Jetstream of levels of 500 and 850 millimeters on the studied area. Following this phenomenon, the thunderstorm intensely affected the region by its destructive effects with the formation of clouds of cumulus and lightning, and finally, heavy rainfall. However, it should be mentioned that for two cases, that is, the phenomenon of February 4, 2007 and December 12, 1991, they experience a more unstable climate due to the average circulation patterns compared to the other identified case, i.e. the phenomenon of April 17, 1991.

Heavy precipitations and severe floods are one of the most important hazards affecting many parts of the country, including the northwest of the country, and it causes extensive damage to farms, gardens, houses, urban facilities, etc. In this research, the atmospheric conditions accompanying the occurrence of flood events in the northwest of the country on April 14, 2017 are studied. For this purpose, the data of sea level pressure, geopotential height, vertical velocity, zonal and meridional components at pressure levels of 850, 700, 500 and 300 hpa, as well as specific humidity in pressure levels of 1000 and 850 hpa(12 hours before the flood event) were obtained from European Centre for Medium-Range Weather Forecasts with a .075 -degree spatial resolution and the desired maps were drawn and the following results were obtained. The presence of severe gradient of pressure in the sea level in the northwestern region of the country and the high humidity in the lower atmosphere as well as the presence of western troughs at all levels of the troposphere exacerbate the meridian flows, and cause the subsequent formation of jets at a pressure of 700 to 300 hpa on the northwest region of Iran. On the other hand, extreme ascent, due to the severe vertical shear of the horizontal wind and the presence of a great deal of moisture, especially in the lower layers of the atmosphere, have created cumulonimbus clouds from a pressure level of 850 to 370 hpa, with lightning strikes at a pressure of 850 to 600 hpa. All of the above conditions have caused the instability and flooding and extreme precipitations in this region of the country.

This study examines the impacts of management ability on financial statement comparability in 120 firms listed in the Tehran Stock Exchange, during 2005-2017. In this study, the measure developed by Demerjian et al. (2012) was used to assess management ability, and the measure introduced by DeFranco et al. (2011) was used to specify accounting comparability. Panel data and multivariate regression models were taken to test the study hypothesis and analyze the results. Also, two alternative proxies for financial statement comparability were specified to re-test the hypothesis. Findings from the above tests verified the findings of the study showing that the management ability has positively significant impact on financial statement comparability. This study suggests that firms can improve their financial statement comparability by employing higher quality managers.

Oryza sativa is one of the crops which can be cultivated in warm and humid climates with relatively high rainfall or large areas of terrestrial water and underground water. One of the most suitable region for rice growing is the northern provinces of Iran. In this study, the rate of evapotranspiration of Oryza sativa in different stages of growth (May to August) has been obtained in three provinces of Iran (Gilan, Mazandaran and Golestan). First, the evapotranspiration of the reference plant in selected stations was calculated using the FAO Penman-Monteith method, and then by the product of the rice plant's coefficient in the reference values of evapotranspiration, the amount of evapotranspiration of Oryza sativa was obtained at different stages of growth. The results indicate that the maximum evapotranspiration of the Oryza sativa in the middle stage and the minimum of this index occurred in the final stage of grows (except Manjil station). Also, the evapotranspiration in the middle stage of grows (June and July) is around 65 – 70 % of the total evapotranspiration in the most stations. The rate of evapotranspiration of rice in all stages of growth decreases from the east (Marave tappeh station) to the west (Astara station) of the region (except Manjil station). In contrast, the rate of precipitation during the period of growth of this product from east to west is increasing. For instance, the precipitation at Marave Tappeh and Gorgan are supplied respectively 9 and 20% of the water demand of this product while in the stations of Mazandaran and Gilan provinces, about 30-50% of the water demand of this product is provided by rainfall.

Theory of constraints is a managerial view which aims at increasing the system efficiency by identifying constraint processes. Present study aimed to apply the theory of constraint in scheduling system of a healthcare facility in order to increase efficiency and decrease patient wait times.
The present research was a descriptive-analytical study through using cross-sectional method on 130 patients of a cancer treatment center. To simulate the patient flow, a discreet event simulation model was employed. The required data for simulating the patient flow were acquired using a questionnaire from patients and direct observation. After simulating the model in Simul8 software, different scenarios were developed and their effects were tested on patient wait times and system output.
The results from the simulation of different scenarios showed that using the third scenario, which was based on the theory of constraints principles, could balance the trade-off between average wait times and average system output. In comparison to output maximization scenario, only by a 4.36 percent decrease in average daily patient output, drum buffer rope (DBR) scenario improved average waiting times by 41.39 percent. On the other hand, relative to minimizing the wait time scenario, DBR scenario increased the average daily patient output by 29.97 percent, while increased the average wait times by 11.66 percent.
Findings showed that employing the concepts of theory of constraints in healthcare can be significantly effective in managing the bottlenecks, reducing patient wait times, and improving system efficiency.

Historical sources have spoken about the spread of religious conflicts during the rule of Buyid Dynasty in Baghdad. This is while many years before Buyid Dynasty dominated in that city, Sunni and Shiites resided in that city. The main problem in this study is that with the power of Buyid Dynasty in the form of a Shiite government, what changes have been created in the policies of this sovereignty and the management of affairs in Baghdad which have led to religious conflicts. A review of the sources indicates some factors among which the most important are: 1) Religious Fanaticism of Shiite and Sunni Muslims 2) The behaviors of community rulers, their weakness in management and their political power in this period 3) Economic motives 4) Role playing of the scholars and jurisprudents of Baghdad.