Showing 253 results for Distribution
Volume 0, Issue 0 (2-2024)
Abstract
Distributional semantics is a neo-constructuralist method that focuses on the use of words in real texts to understand the approximate meaning of a word, compared to other words. Since one of the goals of applying semantics in Quran, is to know the meaning of words according to practical context, the use of this method in Quran becomes important. In this research, in order to introduce the application of distributional semantics in the Qur'an, with the descriptive-analytical method, the steps of implementing, the challenges and solutions to overcome it, have been explained by examining a case study.The steps are: determining some words to compare with the main word, determining distributional features (surah, equivalent to document, and phrase), linguistic pre-processing of the Qur'anic text and removal of stopwords, forming context vector and co-occurrence matrix and weighting its elements, finding semantic similarity of words and its analysis. The most important challenges of using this method in Qur'an are the small volume of the Qur'anic text, the lack of suitable software for calculations in Quran, and the great difference in the length of surahs in the word-document pattern. Paying more attention to the basis of the distributional method (distributional hypothesis), not using this method for very low-frequency words, and comparing the results obtained from the word-document and word-phrase patterns are solutions to overcome some challenges. For the root-word Farah, it is obtained that the meaning from the Qur'anic context (close to the meaning of pride) is different from the meaning mentioned in dictionaries (joy).
Volume 0, Issue 0 (8-2024)
Abstract
In order to facilitate the release of floods from the dams and to prevent their damage or collapse, a structure called a spillway is used. Due to the natural and variable flow of the input to the reservoirs of the dams, there are times when the river inflow exceeds the consumption amount in the downstream agricultural lands. In these cases, excess water is discharged over the crest of the weir and flows towards the spillway, which causes high velocities. This high velocity creates low pressure areas on the spillway concrete surface, which can cause major damage to the spillway or even endanger the integrity of the dam structure. Therefore, the dam spillway must safely dissipate the kinetic energy. One of the types of weirs is the stepped spillway to facilitate the passage of the flow over the dams. One of the most obvious practical features of stepped spillways compared to other spillways is the considerable energy dissipation along the spillway. Care should be taken in designing and selecting the type of spillway to prevent potential erosion and reduce kinetic energy as the water flow passes over the spillway. One possible solution is to use a stepped spillway instead of a smooth spillway. In this study, a numeral model of a stepped spillway with different steps and slopes is used. For this purpose, ANSYS software is used for modeling free surface with application of k-ε turbulence model. In the present study, numerical simulation using the Volume of Fluid (VOF) model was used to investigate the mixing phenomenon of two phases of air and water of the free surface flow. The flow field was continued until the residuals reached 10-7. Compared to simpler models such as Mixture, which operates solely on the basis of averaging the properties of two phases, the VOF model, is separating the phases and considering the effects of the interface. The VOF model, is capable of more accurate simulation of phenomena such as fluid mixing, turbulent flows, and heat transfer in multiphase flows. A number of hydraulic specifications which are considered in designing the stepped spillways are the pressure on the surface of the steps, velocity distribution and energy dissipation. The results from the numerical models were compared with experimental studies. They showed acceptable agreement with physical simulations. Results show that discharge and spillway slope increment reduces the amount of energy loss. In the spillway with 5 steps, for a discharge of 0.063 m3/s, the amount of energy dissipation at a slope of 26.6 degrees changes from 85 to 82% at a slope of 45 degrees, which shows a decrease of 3%. With the increase in discharge, the flow depth increases and reduces the effect of the roughness of the steps on the upper layers of the flow. Increasing the height of the steps increases the rate of energy dissipation and also increases the occurrence of negative pressures in stepped spillway. In this case, the contact surface between the main flow and the eddy currents increases. With the increase in the height of the steps, the dimensions of the rotating vortices also increase and cause a larger radius of rotation on the steps. The presence of these large rotating vortices separates the flow from the bottom of the steps and reduces the pressure on the surfaces. The number and dimensions of steps can alter the energy dissipation rate. Increase in the number of steps in a spillway with constant height, reduces the energy loss as the result of steps dimensions being shrunk
Volume 0, Issue 0 (12-2024)
Abstract
Aim and Introduction
This paper examines the distribution of income in Iran from 2006 to 2016 and evaluates the validity of one of the latest economic theories concerning income distribution, namely, the Econophysics Two-Class Theory of Income Distribution (EPTC).
According to this model, income distribution generally comprises two classes. The lower class of this distribution, typically representing 97 to 99% of th society, follows the exponential (thermal) Boltzmann-Gibbs distribution, primarily driven by labor income. This distribution remains stable over time and undergoes minimal fundamental changes. Conversely, the income distribution of the upper class, constituting approximately 1 to 3% of society, follows the Pareto distribution, recognized as a superthermal distribution in econophysics. Notably, this distribution exhibits high variability over time, closely mirroring fluctuations in the stock market.
For this study, a review of the theoretical literature on the statistical distribution of income is conducted, tracing its evolution from Pareto's initial attempts to the formulation of the two-class distribution of income. In the methodology section, emphasis is placed on delineating the characteristics of two Probability Density Functions (PDFs) and Complementary Cumulative Distribution Functions (CCDFs) associated with exponential and Pareto distributions. The methodology elaborates on the approach to detecting income distribution patterns within the framework of the aforementioned theory. Subsequently, in the data and findings section, an examination of the income data spanning the specified time period in Iran is undertaken. The section meticulously explores the compatibility of these data with the EPCT, offering detailed discussions on the observed patterns and their alignment with the theoretical framework. Finally, the implications of the EPCT are elucidated, and the paper's conclusions are presented in the concluding remarks section.
Methodology
In complex systems concluding big data or complex models, alternative approaches beyond conventional statistical tests may be employed to estimate distributions. Visual inspection and descriptive analysis, facilitated by histograms and distribution charts, serve as effective tools for approximating distributions without relying on statistical tests. The selection of distributions is informed by theoretical considerations that align with the underlying characteristics of the system. These alternative methods offer practicality and informativeness, particularly in scenarios where traditional statistical assumptions may not hold or when dealing with extensive and unconventional data. The present article adopts this methodological approach to analyze income distribution in Iran.
The initial step involves drawing the histogram and probability density function (PDF). The shape of the histogram guides the identification of distribution. Given the potential complexity arising from large datasets, and the ambiguity that may arise from visual inspection of merely the PDF, a Complementary Cumulative Distribution Function (CCDF) plot serves as a valuable aid. Subsequently, following the first step and the selection of candidate theoretical distributions, the CCDFs are plotted to ascertain the optimal fit with the experimental data distribution. Consequently, the combined use of PDF and CCDF serves as indispensable tools for delineating annual income distribution patterns.
The resemblance between the graphs of the PDF for both exponential and Pareto distributions on a linear-linear scale poses challenges in distinguishing between these distributions. Similarly, the CCDF curve lacks clarity on a linear-linear scale due to this similarity. However, employing a logarithmic-linear scale to plot the survival function related to the data of the lower part of society proves beneficial, as it reveals a smooth line representative of the exponential Boltzmann-Gibbs law. Similarly, plotting the survival function for the upper part of the society on a logarithmic-logarithmic scale serves to elucidate the Pareto power law. Consequently, plotting the survival function for the entire dataset on a logarithmic-logarithmic scale, as per the hypothesis of the EPTC, should unveil two distinct segments: exponential and Pareto.
Findings
The data utilized in this study were derived from the raw tables pertaining to the household expenditure-income (budget) plan, annually published by the Statistical Center of Iran. Specifically focusing on data sourced from the urban population, which constituted approximately three-quarters of the total population during the study period. Data preparation commenced with the meticulous removal of zero and negative values, followed by deflation adjustments based on the consumer price index. Subsequently, data normalization was conducted utilizing the slope of the line of the CCDF for the lower part of the dataset, plotted on a logarithmic-linear scale for each year. This normalization process was initiated based on the initial estimate of the border income, set at the 99.7th percentile. Finally, an appropriate binning strategy was selected, with a uniform value of 0.4 (∆r≈0.4T) applied to all data subsequent to the initial 0.2 portion.
Plotting the PDF of the income pertaining to the lower class of the society across three scales—linear-linear, logarithmic-linear, and logarithmic-logarithmic—alongside the fitting line of the exponential distribution function for the year 2016 revealed a notable alignment, indicative of a robust fit with the theoretical exponential distribution.
Alternatively, the survival function chart was employed to analyze the income distribution among the upper class of society. Presenting this data graphically across three scales—linear-linear, logarithmic-linear, and logarithmic-logarithmic—for the entirety of 2016 underscored two key findings. Firstly, the tail-end distribution of income follows the Pareto distribution. Secondly, and of paramount significance, these graphical representations unequivocally affirmed the appropriateness of dividing the dataset into two distinct segments.
Plotting the PDF for the 11-year period revealed that the data pertaining to the lower part of the society, representing 99.7% of the total population, converged onto a singular curve following normalization across the entire duration under study. Subsequently, depicting the survival functions for the aforementioned 11-year time frame in a unified graph, utilizing both logarithmic-linear and logarithmic-logarithmic scales, served as a more definitive validation of the two-class theory of income distribution.
Discussion and Conclusion
The analysis of income data in Iran from 2006 to 2016 reveals a distinct two-class structure in the country's income distribution.
Firstly, the lower class, encompassing approximately 97 to 99.7% of the population, follows the exponential Boltzmann-Gibbs distribution, primarily driven by labor income. This statistical distribution reflects a cumulative process characterized by a constant rate of decrease, as indicated by the exponential distribution's parameter. The consistency observed in the exponential fit graphs of the survival function and data histogram across different years suggests the stability of income distribution within the lower class over time. This stability parallels thermal equilibrium in physics, suggesting that the majority of the population is in a stable equilibrium. Notably, the high-resolution histogram of the PDF reveals a sharp and narrow peak at low incomes, attributed to governmental policies such as the imposition of minimum wage regulations.
Conversely, the upper class, constituting approximately 0.3 to 3% of the population, follows a Pareto distribution, predominantly influenced by capital income. However, unlike the lower class, the distribution of income within this part does not align along a single line in the power law segment. This part undergoes discernible fluctuations from year to year, indicating instability within this economic sector. These fluctuations are attributed to the variability of capital income
Thangalazhi Balakrishnan Suryanarayanan, Levente Ábrahám, Chenthamarakshan Bijoy,
Volume 0, Issue 0 (9-2025)
Abstract
Indopalpares pardus (Rambur, 1842), Palpares contrarius (Walker, 1853), and Stenares harpyia (Gerstaecker, 1863) are the species of the tribe Palparini which are recorded for the first time from the Kerala part of Western Ghats. All three taxa are redescribed and the genitalia features of P. contrarius, and S. harpyia are illustrated for the first time based on the freshly collected specimens. Lectotype and paralectotype specimens of S. harpyia are designated. The key to the genera of the tribe Palparini from India and the distribution of three species in India are also mapped. Moreover, their flight period in India is plotted.
Juli Pujade-Villar, Majid Tavakoli, George Melika, Mar Ferrer-Suay,
Volume 1, Issue 1 (9-2015)
Abstract
A new species of oak gallwasp, Andricus synophri (Hymenoptera: Cynipidae: Cynipini) is described from Iran. Data on the diagnosis, distribution and biology of the new species are given. This species is known only from asexual females and induces galls on the twigs of Quercus brantii and Q. libani. Galls aremultilocular, develop on lateral buds of young branches. According to its morphology, Andricus synophri belongs to a large group of 12 Andricus species, the “Adleria non-kollari” group.
Volume 1, Issue 2 (9-2011)
Abstract
Introduction of modern technologies such as internet has had some downsides as well. The aim of the present study is to investigate some disadvantages of the integration of modern technology in organizations. The main body of the investigation will concentrate on the effect of different influential factors on cyber-loafing among the members of an organization. Regarding the literature on the subject matter, one of the leading factors that causes cyber-loafing is organizational justice. First, the influence of organizational justice, as the independent variable, on the distributional justice, procedural justice, and interactional justice is be discussed in details. Later on, the moderating role of perception of the organizational control in relation to organizational justice and cyber-loafing will be talked over. For testing the first hypothesis of the study, which focuses on the negative influence of organizational justice on cyber-loafing, the Lisrel software was used in through path analysis and structural equation modeling. The results obtained from 152 questionnaires distributed, among the employees of an automobile company, confirmed the credibility of the first hypothesis. Also the findings did not confirm the idea that the perception of organizational control plays a moderating role with regard to organizational justice and cyber-loafing.
Reihaneh Gholami Gavam Abad, Seyed Ebrahim Sadeghi, Hamid Yarmand, Vahid Reza Moniri, Ali Mohammadpour, Ali Zarnegar, Ali Reza Haghshenas, Mohammad Reza Zargaran, Fatemeh Piruzi, Abbas Salahi Ardakani, Stephen P. Cook,
Volume 1, Issue 2 (12-2015)
Abstract
From 2009 to 2012, 16 species of Curculionidae (Coleoptera) from the subfamily Lixinae were collected on 17 species of food plants in Iranian rangelands. Identified species belong to seven genera in the tribes Lixini and Cleonini. The host plants from which they were collected were in the families Asteraceae, Fabaceae, Apiaceae, Campanulaceae, Brassicaceae and Zygophyllaceae. Of the 16 species that we captured, two (Lixus subfarinosus Desbrochers, 1893 and Larinus remissus Faust, 1889) represent the first records from Iran. These new data also extend the known ranges of several species (Larinus fucatus Faust, 1894, Larinus grisescens Gyllenhal, 1835, Microlarinus rhinocylloides Hochhuth, 1847 and Bangasternus planifrons (Brulle, 1832) in Iran. The distribution of beetles and their associated host plants are presented and ecological notes on each species are provided.
Mohammad Mehdi Rabieh, Mahnaz Allahverdi, Issa Jabaleh, Mehdi Esfandiari,
Volume 1, Issue 2 (12-2015)
Abstract
The genus Euxoa Hübner, [1821] is regarded as the most highly evolved among the genera of the subfamily Noctuinae and contains by far the largest number of species of the subfamily in Europe and in the Palaearctic region. Fifty-four species of this genus has been already reported from Iran. In this paper a list of 17 already recorded species and subspecies of Euxoa from the north-east of Iran is given and discussed. Furthermore, E. acuminifera (Eversmann, 1854) is newly reported for the fauna of Iran. Figures of its adult male and female and their genitalia are provided together with bionomics and distribution of the species.
Volume 1, Issue 3 (11-2011)
Abstract
In recent years the importance of social capital as an intangible organizational asset has been of interest to those concerned with organizational and management issues. Positive levels of social capital are referred to, as a product of positive internal organizational social relations. The goal of this paper is the study of the relationship between the Iran Insurance employees’ understanding of organizational justice and social capital in the branches of the state of Gillan. Research method used is descriptive and of the Pyrson Correlative type. The statistical populationincludes all employees of Iran Insurance in the state of Gillan (altogether 492 people). Considering Cohen, Morgan and Krisay’s table, the sample size chosen was 220 people. The data collection tool used was a questioner which was field conducted. In order to asses levels of social capital the questioner designed by Gyshal and Nahpyt (1998), with 16 buoy was used; and to asses social justice levels a standard questioner with 19 buoys using the Leickert scale was employed. Validity of the research tool was based on the expert opinion of a group of experts. The social capital questioner’s stability, and the verification of the reported levels of organizational justice were approved by the use of Cron Bach’s 0/896 and 0/916 levels respectively. For data analysis the Pearson correlation test was used. Test results and the single-sample T-test showed that between the dependent research variable (social capital), and the independent research variable (organizational justice), and its’ different dimensions(Distributional, procedural, relational, and informational justice), a 99% positive correlation exists.
Tahereh Tavakoli Roodi, Majid Fallahzadeh, Hossein Lotfalizadeh,
Volume 2, Issue 1 (3-2016)
Abstract
This paper provides data on distribution of 13 chalcid wasp species (Hymenoptera: Chalcidoidea: Chalcididae) belonging to 9 genera and three subfamilies Chalcidinae, Dirhininae and Haltichellinae from Hormozgan province, southern Iran. All collected species are new records for the province. Two species Dirhinus excavatus Dalman, 1818 and Hockeria bifasciata Walker, 1834 are recorded from Iran for the first time. In the present study, D. excavatus is a new species record for the Palaearctic region. An updated list of all known species of Chalcididae from Iran is also included.
Volume 2, Issue 2 (6-2013)
Abstract
Edaphic Mesostigmata are important, because these feed on arthropods and other invertebrates which may affect on natural equilibrium position of oter living micro-organisms. In order to study the fauna of mesostigmatid mites, samples of soil, litter were collected from different parts of Esfahan region. Mites were extracted by means of Berlese funnel, cleared in Lactic acid and mounted with Hoyer's medium. In this research, the world and Iranian distribution of species with some information about their habitats were provided. Two genera and 3 species were recorded as new records for Iran mite fauna that are marked by an asterisk. The list of identified genera and species is as follows: Ascidae: Arctoseius cetratus (Sellnick, 1940), A. pristinus* Karg, 1962, A. venustulus (Berlese, 1917), Gamasellodes bicolor (Berlese, 1918); Blattisociidae: Lasioseius sugawarai Ehara, 1964, L. youcefi Athias-Henriot, 1959; Melicharidae: Proctolaelaps pygmaeus (Muller, 1860); Parholaspididae: Proparholaspulus* angustatus* Ishikawa, 1987 Trachytidae: Uroseius* traegardhi* (Hirschmann & Zirngiebl-Nicol, 1969).
Volume 2, Issue 2 (9-2013)
Abstract
Aquaculture production is often accompanied by some stressors which undesirable effects on growth and physiological function. Music is one of the cases that could eliminate or reduce the effects of stressors. The purpose of this study was to determine the effect of Iranian traditional music on growth, reproduction and behaviour of zebra cichlid (Pseudotropheus zebra). Fish with an average weight 5.5 0.18 g were put under both music and silence treatment with the number of 2 fish/aquarium with 3 replicates for 4 weeks. Fish under music treatment were put twice a day and every 30 minutes under the Iranian traditional music. At the end of this period, suitable conditions for fish were created to spawning. The results showed no significant differences in growth parameters, but 50 percent of fish during the 2-week were spawned in music treatment. However, only 16.6 percent of fish under silent treatment were spawned. Of eggs and spawn time, significant differences were observed between two groups. When is music being played, the fish were found mainly along approach the speakers, while the distribution of fish treated silence was uniform. The results of present study showed that use of music can affect physiological function of fish, which have more tranquility and less stress on fish.
Volume 2, Issue 2 (4-2000)
Abstract
Environmental factors mainly temperature are believed to determine the
distribution and population dynamics of Fusarium species in a natural ecosystem.
Species may be restricted in their distribution by adaptation to specific sets of soil
environmental conditions. Population dynamics of five Fusarium species representative
of different climatic conditions were studied at three levels of temperature (13-18 /
19-24 / 25-30°C) and constant water potential (field capacity). Temperature had a
significant influence on the population level of all test Fusarium species. Fusarium
sambucinum showed noticeable reduction of population at warm temperatures. The
population of F. solani and F. compaction were higher at high temperatures. The
population of cosmopolitan species, F. equiseli showed little change at all experimental
conditions, Fusarium acuminalum did not compete well with other species in this
experiment, its population being low at all treatments.
Alireza Pourhaji, Hossein Lotfalizadeh, Reza Farshbaf-Pourabad, Babak Gharali, Abbas Mohammadi-Khoramabadi,
Volume 2, Issue 2 (6-2016)
Abstract
This study was conducted to collect and identify ichneumonid parasitoids of tephritid fruit flies (Diptera: Tephritidae) feeding on the plants of the family Asteraceae in the northwest of Iran during 2013-2015. Five species of ichneumon wasps on five species of fruit flies were reared. They were as follows: Cremastus lineatus on Urophora terebrans; Diadegma maculatum on Hypenidium robrowskii; Scambus brevicornis on Sphenella marginata, Scambus rufator on Terellia gynacochroma and Urophora sp. and Tranosema sp. on Tephritis sp. dioscurea group. Of them, Cremastus lineatus, S. rufator and Tranosema sp. are new records for ichneumonid fauna of Iran. All host-parasitoid-plant associations were newly established to the science. General distribution of these parasitoids and their biological associations were discussed.
Farzad Pakarpour Rayeni, Ali Asghar Seraj, Jamasb Nozari,
Volume 2, Issue 2 (6-2016)
Abstract
A faunal study of leafhoppers (Hemiptera: Auchenorrhyncha: Cicadellidae) was conducted in some parts of Khuzestan Province (southwest of Iran) in 2014 and 2015. Totally, 90 species belonging to 49 genera and seven subfamilies were collected and identified. Most of samples were collected by using sweeping net and Malaise trap and a few by aspirator and sticky yellow trap. As a result of this study 47 species are recorded from Khuzestan Province for the first time and eight species are new records for the fauna of Iran including Euscelidius schenckii (Kirschbaum, 1868); Hardya (Hardya) melanopsis (Hardy, 1850); Paradorydium (Paradorydium) lanceolatum (Burmeister, 1839); Hecalus prasinus (Matsumura, 1905); Psammotettix emarginatus Singh, 1969; Grammacephalus pallidus (Linnavuori, 1978); Helionidia punctulata (Ramakrishnan and Menon, 1974) and Eupteryx (Eupteryx) kaghanensis Ahmed, 1969. For each species geographical distribution in Iran are completely mentioned. In addition morphological data and illustration of adults and their male genitalia are given for the eight newly recorded species.
Volume 2, Issue 2 (12-2020)
Abstract
The present study investigates relation between coastal zons with urban human structures in sea states. Urban human structures are urban populations, coastal cities, world cities and coastal capitals. This research is basic in terms of its objective and is descriptive-analytic in terms of nature and method. This paper uses qualitative and quantitative analysis to explain the relationship between the two variables of coastal zons and urban human structures. The ratio of low elevation coastal zone (less than 10 meters from the coast) to the total surface area of the country is an explanatory indicator of coastal topography, and the ratio of the population living in the coastal zone to the total population of the country is an explanatory indicator of the coastal population. The findings of the research indicate that the coastal area is one of the factors in the development of urban human resources. Regression analysis shows that the correlation coefficient of coastal zone topography with the distribution of population equals with 0.812 (P Value 0.000<0.05). The results show that there is a significant relationship between topography of the coastal zone and the distribution of population, to the extent that for every one-unit increase in topography of the coastal region, the distribution of human populations index size increases by 0.833 (constant 0.070). Besides, the opportunities and threats of population settlement in coastal zone are analyzed in the following section of the article.
Md. Samsur Rahman, Ibrahim Khalil Al Haidar, Amit Kumer Neogi, Md. Ashraf Ul Hasan, Md. Mizanur Rahman, Sheikh Muhammad Shaburul Imam,
Volume 2, Issue 3 (9-2016)
Abstract
During the study of butterflies of Bangladesh (Insecta: Lepidoptera) which carried out since June 2014 to March 2016, several expeditions were made by the authors in the different areas of Bangladesh and many butterfly species were collected and identified. Among them, five species namely, Zezius chrysomallus Hübner, 1823, Rapala tara de Niceville, 1988, Cethosia biblis Fruhstorfer, 1912 and Atrophaneura coon Fabricius, 1793, Cephren estrichopepla Lowe, 1908; and one subspecies, Pelopidas subochracea subochracea Moore, 1878 are newly reported for the fauna of Bangladesh and their distribution data are presented. This study was achieved with an aim to update the checklist of butterflies of Bangladesh. The previous sampling gaps in some areas of Bangladesh indicated by these newly reported species which may put forward further investigations on the butterflies of this country.
Zahra Goodarzifar, Seyed Massoud Madjdzadeh, Mohsen Mehrparvar,
Volume 2, Issue 3 (9-2016)
Abstract
So far, three aphid species including Aphis fabae Scopoli, 1763, Brachycaudus cardui (Linnaeus, 1758) and Paczoskia meridionalis Holman, 1981 are reported on Echinops in Iran. In this study, two more aphid species were collected on Echinops in Iran: Myzus persicae(Sulzer, 1776) and Turanoleucon jashenkoiKadyrbekov, 2002.The little-known aphid genus Turanoleucon and the species T. jashenkoiare reported here for the first time from Iran. The biometric data of apterous and alate viviparous females of Iranian population of T. jashenkoiare given from specimens collected from Fars province, Iran. The morphological differences between Iranian population and the original description of the species, i.e. Kazakhstan population, are discussed. An identification key to the apterous viviparous female aphids living on Echinops in Iran is provided.
Volume 2, Issue 4 (4-2011)
Abstract
By the establishment of local semi-independent governments in the southern shores of the Caspian Sea, Iranian north provinces were cover of conflicts between the local governors with Omayyad and Abbasids Caliphates. Supplying political security in Tabaristan and creating suitable conditions for economic development led to formation of multiple garrisons in the vast geography of the region.
These buildings, by the historical and geographical sources, have been nominated as Maslah-i-, Sakhlou and Zeynistan. The Garrisons in Abbasids period. Were built by Abol-Abbas-i- Tousi.
The geographical coverage of these garisons included in Plain, jungles and Mountainous areas. Starting from Tammish-i- city in the east of Tabaristan to the Chalous city in the west.
The quantity of garrisons has differed between 31, 45 to 50 numbers.
In this research, we recognized 31 garrisons. Also we tried determine the distribution of garrisons according to historical and geographical sources.
Volume 2, Issue 4 (3-2014)
Abstract
Identification of intertidal echinoderms and the effect of environmental factors on their density and distribution in five stations around the Khark Island were seasonally investigated. Three transects were designated to cover the supralittoral, eulittoral and sublittoral zones within each station. The environmental factors such as temperature, salinity and total organic maters (TOM) were also recorded. Maximum and minimum water temperature were recorded in summer (35.94 ± 0.28) and in winter (18.34 ± 0.39) and the maximum and minimum salinity were recorded in winter (44.6± 0.14) and spring (37 ± 0.18), respectively. Maximum and minimum percentages of total organic maters (TOM) were observed in summer (9.63 ± 0.71) and winter (3.39±0.15), respectively.Totally four species belonging to for families were identified, viz. Asterina burtoni, Echinometra mathaei, Holothuria atra, Ophiothrix sarignyi, the highest frequency of which was encountered by E. mathaei. The maximum density and distribution were found in spring and minimum in summer and winter.
