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Showing 43 results for Samadi
Volume 2, Issue 3 (Summer 2022)
Abstract
Aristotle's discussions about Tuche (Τύχη) or fortune have obvious contradictions in two domains of ontology and axiology. In the domain of ontology, he has testified to the existence of fortune as a cause by accident- a cause by accident for an event which has occurred out of a choice based on thought and for a given intention. Aristotle believes that fortune-based affairs are subjects of intention and intellection which emerge from those agents who can take volitional actions. At the same time, he introduced fortune as an anti-rule and instable affair with indeterminate and purposeless causes. He accepted the existence of fortune even in the domain of the actions related to Techne and human happiness. However, he does not attach any value to it in axiology and declares it to be a cause by accident that comes after nature and intellect, even believing that there is no knowledge for it. Moreover, it is valueless in the domain of the action related to human happiness.
Volume 2, Issue 4 (Fall 2022)
Abstract
Orexis or desire in Aristotle’s point of view is divided into rational and irrational desires. Rational desire includes Boulêsis while irrational desire includes Epithumia (appetite) and Thumos (passion). The study of Aristotle’s ideas shows that rational desire is different from other types of desire from different aspects. Firstly, rational desire as compared to the appetite and passion belongs to the rational part of the soul and thus is exclusively for human being whereas appetite and passion exist in animals too. Secondly, rational desire is concerned with goals which are realized through rational deliberation and such goals are good from the point of view of the agent instead of being merely pleasant and pleasurable. Thirdly, rational desire is engaged with the identification of truth and also contrary to the appetite and passion is a future-oriented desire. Finally, the striking feature of rational desire is its being an origin for moral actions; because the issue of rational desire is a rational goal; something from which the animals are deprived.
Volume 3, Issue 2 (Number 2 - 2001)
Abstract
A field study was conducted to evaluate the agronomic response of eight isolines of cv. Clark on a clay loam soil (at Karaj-Iran, 35048´) to four plant population densities of 11.3, 18.5, 68.5, and 103.4 plants per square metre. Significant yield increase was obtained as a result of higher plant density. Differences among the cv. Clark isolines were significant (p<0.05). Yield components such as numbers of branches, pods, and seeds per plant decreased linearly as population density increased. Adjustments in pods and seeds per plant resulted from altered branches per plant. The isolines which exhibit profuse branching (e.g. E1E2E3, E1e2E3, E1E2 e3) were capable of optimising yield when planted at low densities. The second dynamic factor that aided yield compensation by plant population density was greater total dry matter partitioning, which resulted in a significantly greater harvest index at the lower compared with the higher plant density. The results indicated that total biomass and crop growth rate were the major elements explaining the reduced yield compensation factors at higher plant population density. Plotting the fitted seed yield values against the number of dominant alleles showed the effect of the maturity genes on the response of seed yield to plant density.
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 4, Issue 1 (3-2016)
Abstract
Wetlands as a situ for the growth of native plants, as a habitat for certain species of fish and aquatic birds, and because of their potential economic, cultural and recreational services, are valuable heritage so their protection and conservation is very essential. Mostly due to the absence of wetlands services’ valuation, lack of special regulations, and lack of guarantee for these properties, resources and services of wetlands are not utilized appropriately, and destructed and evacuated in a free and unrestricted fashion, leading to inefficiency in use. The purpose of this study is the economic valuation of Gavkhony wetland ecosystem attributes, estimation of implicit price for attributes, impact assessment of socio-economic variables such as age, marriage, indigenous, family size and education on willingness to pay (WTP), and analyzing welfare and compensation variation due to variation of hypothetical policy. The approach being used is choice experiment that is a subset of choice modeling procedure and stated preference method. Data were collected from six different choice experiments provided in the questionnaires, which were filled out by 500 randomly selected households in Isfahan and Varzaneh cities in the spring and summer of 2013. Each questionnaire contained 72 hypothetical policies, 36 choice sets, 2442 observations and 7327 rows of data. Nested Logitech models and Hausman-MacFadden test were used in order to estimate the visitors’ WTP for improving attribute levels for Gavkhony wetland. This procedure was used on the basis of multinomial discrete choice analysis of preferences, Lancaster’s theory of value and the theory of random utility function. The Hausman-MacFadden test results showed that cross-elasticity between the first and third options was the same. Thus, these two options were placed in the second nest. The results further showed that the visitors had WTP for preserving forest diversity and vegetation of wetlands and its surrounding; preserve of natural habitats and organisms life of wetland (bird, fish and animals); wetland hygiene (preventing industrial and domestic effluent, and water salinity); and increasing the water surface (increasing wetland water inlet). The values estimated for these four aspects correspondingly were 8636, 12584, 11553 and 4740 Rials. Some socio-economic variables such as gender, marriage, age, family expenditure, education and being native had a positive impact on the visitors’ WTP. The surplus welfareresults showed that in 72 hypothetical policies, option 1 had the most positive welfare, and option 5 had the most negative welfare for the users of Govkhony wetland. The surplus welfare results based on WTP estimation provide important tools for policy making.
Volume 4, Issue 3 (Number 3&4 - 2002)
Abstract
Two barley (Hordeun vulgare L.) genotypes, Radical and Cwb, with good to moderate levels of resistance to powdery mildew were crossed with a highly susceptible cultivar (Afzal) to determine the genetics of resistance. The parents, Fl, F2 and F3 generations of each of the two crosses, were evaluated for powdery mildew resistance in the glasshouse and field at the College of Agriculture in Karaj during 2000. The x2 analysis of the segre-gating ratios in the F3 generations indicated that the resistance was controlled by one gene at seedling stage and by two or three genes at adult plant stage in Cwb and Radical, respectively. Radical showed a higher level of resistance than the Cwb, therefore, it is a better source of resistance to powdery mildew.
Volume 4, Issue 3 (fall 2023)
Abstract
Problem: The concept of urban public art and its emergence in the public sphere is one of the most important factors in strengthening and accelerating the process of the creative city. Street music as an urban public art, is an influential event in urban communities that seeks to improve the quality of social life, strengthen collective memories, increase the level of vitality and dynamism of the city and achieve creative urban development. Target: The authors try to redefine the importance and significance of the urban public arts event in urban spaces, identify the feasibility of performing street music in social environments. The green corridor of Shahrchai and the Khayyam Jonubi sidewalk of Urmia city have been studied. Method: In this regard, in the present study, information has been collected with the aim of application and descriptive-analytical nature and by using documentary-library methods, questionnaire and interview tools. The statistical population and sample size consist of two groups of experts, thinkers and university professors and active members of street music, which includes 60 samples including stratified or group sampling method. For quantitative analysis, the methods of Kolmogorov-Smirnov, Spearman Correlation, Swara and Cocoso have been used. Result: According to the findings, the social, cultural and environmental dimensions and the indicators of "possibility of live music performance" and "quality of environmental design" have gained the highest and lowest levels of importance, respectively. Also, the green corridor of Shahrchai has more favorable conditions than the performance of urban Public arts (street music) compared to the Khayyam Jonubi sidewalk of Urmia.
Volume 5, Issue 2 (summer 2024)
Abstract
Problem: Justice in urban health means the absence of systematic differences in one or more aspects of the health status of citizens or population groups in terms of social, economic and physical environment. In the present study, the city of Urmia has been investigated and analyzed as a focus of studies on the level of realization of the right to health approach to the city and the distribution of health-therapeutic services and functions.
Aims: In terms of its purpose, the current research is in the category of semi-basic, semi-applied research, which is carried out with descriptive and analytical method.
Methods: The methods of collecting information are based on documentary-library methods, observation and field verification (Swara and Cocoso tests).
Findings: Based on the results, the city of Urmia has not acted in a fair manner in terms of the distribution of health-treatment functions and services in accordance with the approach of the right to the city, in spatial planning and allocation.
Conclusion: Regions 4 in the central context and the commercial pole of the city and 2 in the peripheral part of Urmia city have respectively the most favorable and unfavorable environmental conditions and conditions in the matter of enjoying the right to health policies of the city. In the end, based on the findings and the identification of the strengths and weaknesses of the study area in the field of urban development, some targeted and sustainable proposals and actions have been taken to improve the environmental conditions.
Volume 6, Issue 1 (Winter 2020)
Abstract
Aims: Brucellosis is one of the most common diseases between humans and animals (zoonosis); one of its transmission routs is through the consumption of infected cattle dairy products. Since Sarab city has a large cattle population, and traditional dairy production and processing practices are still prevalent in this region and are known as tourist attractions and souvenirs of the region, this study aimed to investigate the prevalence of infection in employees of traditional dairy products workshops in Sarab in 2018.
Materials & Methods: This descriptive cross-sectional study was conducted on 196 employees of traditional dairy production and packaging workshops. Blood samples were obtained from all subjects in order to determine the serological status of the patients. After sera isolation, Rose Bengal, seroagglutination in tube (Wright), 2-mercaptoethanol (2ME), and ELISA tests were used to evaluate them.
Findings: In this study, the disease prevalence in the subjects with the mean age of 33±4.2 years was determined as 2, 1, 1, and 1% using Rose Bengal, Wright, 2-mercaptoethanol, and ELISA tests, respectively. The mean knowledge score of the employees in dairy products workshops was 31±5.7, and by increasing age and duration of work, knowledge about brucellosis was also increased
Conclusion: In this study, the mean knowledge score showed the average knowledge of the subjects about brucellosis. The disease prevalence in this occupational group was lower than that reported in other studies conducted on other at-risk occupational groups in other parts of Iran and the world. Therefore, health personnel should take the necessary measures against brucellosis.
Materials & Methods: This descriptive cross-sectional study was conducted on 196 employees of traditional dairy production and packaging workshops. Blood samples were obtained from all subjects in order to determine the serological status of the patients. After sera isolation, Rose Bengal, seroagglutination in tube (Wright), 2-mercaptoethanol (2ME), and ELISA tests were used to evaluate them.
Findings: In this study, the disease prevalence in the subjects with the mean age of 33±4.2 years was determined as 2, 1, 1, and 1% using Rose Bengal, Wright, 2-mercaptoethanol, and ELISA tests, respectively. The mean knowledge score of the employees in dairy products workshops was 31±5.7, and by increasing age and duration of work, knowledge about brucellosis was also increased
Conclusion: In this study, the mean knowledge score showed the average knowledge of the subjects about brucellosis. The disease prevalence in this occupational group was lower than that reported in other studies conducted on other at-risk occupational groups in other parts of Iran and the world. Therefore, health personnel should take the necessary measures against brucellosis.
Volume 6, Issue 2 (Spring 2018)
Abstract
Aims: Organizational Citizenship Behavior (OCB) and Organizational Justice (OJ) improve the effectiveness of work groups, in which they are exhibited. The aim of this study was to investigate the correlation between organizational citizenship behavior and organizational justice among Textile Industries’ Employees of Red Crescent Society of the Islamic Republic of Iran.
Instrument and Methods: The population of the present descriptive-survey study, which was conducted in 2015, comprised 180 employees of Textile’ Industries in Red Crescent Society of the Islamic Republic of Iran, Tehran, using simple random sampling method. The employees who participated in this study were asked to complete 3 questionnaires, containing demographic questions, OCB (Mark´oczy and Xin,), and OJ (Fernandes and Awamleh,). The data were analyzed by SPSS 19 and LISREL 8.54 software, using Pearson Correlation Test (PCT) and Goodness-of-Fit indices.
Findings: There was a positive and significant correlation between OJ and its dimensions and employee’s OCB (r=0.560; p<0.01) and its dimensions, indicating that the employees, who perceived their organization, managers, and supervisor’s gestures fairly, represented high levels of organizational citizenship behaviors. Given the root mean square error of approximation (RMSEA) normal χ2 and indices of GFI, CFI (comparative fit index), NFI (normed fit index), and IFI (incremental fit indices) showed high fitness of model and that the associations between variables were logical according to theoretical of the study.
Conclusion: Organizational justice has a direct and positive effect on employees’ organizational citizenship behavior.
Saeed Samadi, Khadijeh Nasrollahi, Mortaza Karamalian Cichani,
Volume 7, Issue 3 (10-2007)
Volume 7, Issue 3 (10-2007)
Abstract
Financial markets play a vital role in supplying and facilitating the flow of funds into production and industry sectors of economy and can result into the acceleration of economic growth. Indeed, many experts believe that the development of financial markets acts as the engine for growth. The main objective of this paper is analyzing the relationships between financial market development and economic growth through focusing on Iranian economy and thirteen other countries for the period 1988-2003. In this regard in addition to the Beck and Levin model (2003), we have used three versions of Granger–Casualty approach, Cointegartion test and panel data estimation procedure. Casualty test shows that in Iran, bank and stock market size have no strong effect on economic growth despite the fact that the effect of economic growth on stock market is positive and meaningful. The results of panel data estimation revealed that in real terms, investment and labor force, positively and strongly affect economic growth. In the money sector, the effects of banking system are statistically acceptable, although the positive effect of stock market is not statistically acceptable. The absence of Long–run co integration relation between financial markets and economic growth for the period 1976-2003 is the result of Auto-Regressive Distributed Lag Estimation. In sum, the long – run relation between money market and economic growth is negative and this true for the Iranian economy.
Volume 7, Issue 4 (Fall 2022)
Abstract
Musculoskeletal Disorders (MSDs) and pains are one of the most common and costly types of injuries that disrupt the function of the involved tissue/tissues, and the function of the affected person. Failure to pay proper attention to pain assessment can have an adverse effect on the patient, disease process, and treatment steps. In order to properly assess pain, one should have a selective and comprehensive perspective, including history taking, disease history, attention to clinical and paraclinical findings, the use of multidimensional quantitative and qualitative structured tools (to assess pain intensity, physical, emotional and social functions), and the use of health-related Quality of Life e (QoL) measurement tools. The purpose of this article is to present a new and brief approach to evaluate of musculoskeletal pain and related cases.
Volume 8, Issue 1 (Number 1 - 2006)
Abstract
To evaluate the relationships between soil inorganic phosphorus P (Pi) fractions, the soil P test and plant parameters such as plant P uptake, dry matter yield, tissue P concentra-tion and relative yield, glasshouse experiments and chemical analyses were conducted on 13 calcareous soils from six agricultural and seven adjacent bushland (virgin soil) sites. Four rates of P (0, 15, 30, 60 mg/kg soil) were applied as reagent-grade KH2PO4 to the soils in a randomised complete block design with three replications. Perennial ryegrass (Lolium perenne cv. Roper) was grown and forage was harvested five times over a period of 210 days. Successive harvesting resulted in the depletion of plant available P as meas-ured by NaHCO3-extractable P, which coincided with the decrease in the plant dry matter yield and P uptake. After five harvests, the order of reduction in Pi fractions induced by cropping without added P was Ca10-P>Al-P>Ca2-P>Ca8-P>occluded-P>Fe-P for the vir-gin soils and Ca2-P>Al-P>Ca10-P>Ca8-P>Fe-P>occluded-P for the agricultural soils. The order of abundance of Pi fractions for P treated-soils was non-occluded Al and Fe phos-phate (Al-P+Fe-P)>secondary Ca-bound P (Ca2-P+Ca8-P)>acid-extractable P (Ca10-P)>occluded-P for both virgin and agricultural soils. Although a marked proportion of added P was transformed into less soluble Al and Fe phosphates, successive harvesting had depleted considerable percentages of these fractions. Highly significant (p<0.001) re-lationships were found for P uptake vs. Olsen-P, P uptake vs. Pi fractions (Ca2-P, Ca10-P, Al-P, Ca8-P, Fe-P) and Olsen-P vs. Pi fractions. NaHCO3-extractable P seems to be ade-quate for evaluating plant available P in calcareous soils. However, the closer relationship for the Fe-P fraction vs plant P uptake than for Olsen-P versus plant P uptake indicates that NaHCO3 may not provide the best estimate of plant available P for calcareous soils. Using stepwise regression analysis, it was found that the Ca2-P fraction was most predic-tive of P uptake (60%), total dry matter (68%), relative yield (74%) and Olsen-P (69%), followed by the Fe-P fraction.
Volume 8, Issue 3 (Number 3 - 2006)
Abstract
Phosphorus (P) sorption in soils is a key process governing its availability to crops. There has been scanty information available on the P sorption characteristics of calcare-ous soils of Western Azarbaijan Province, Iran. In this study, P sorption characteristics and their relationship to soil properties were determined in 36 soil samples belonging to 15 agricultural soil series located in the south of Urmia, Western Azarbaijan Province. Total CaCO3 contents ranged from 10 to 48.5%. Active CaCO3 contents ranged from 1.7 to 20% and were significantly related (r = 0.61, P<0.001) to the total CaCO3 of the soils. NaHCO3-extractable P contents ranged from 4 to 38 mg P/kg soil. The amount of P sorbed by the soils differed among various soil series. The results showed that equilibrium solution P concentration (EPC) was lower (<0.2 mg/L) than the requirement for most crops. The amount of P adsorbed by the soils at 0.2 mg/L EPC ranged from 5 to 114 mg/kg soil. The phosphate adsorption was well described by the Freundlich (r2 = 0.96) and Langmuir (r2 = 0.88) isotherms. The Langmuir maximum adsorption (Xm) and Freundlich coefficient (aF) estimated from Langmuir and Freundlich equations ranged from 127 to 238 mg P /kg soil and from 43 to 211 mg P/kg, respectively. Soil clay content was significantly related to the soil P sorption indices, P0.4 (P sorbed at 0.4 mg P/L, r = 0.40, P<0.01), PBC (P buffering capacity, r = 0.54, P<0.001), aF (r = 0.48, P<0.01), and Xm (r = 0.40, P<0.01). Total CaCO3 and active CaCO3 were found to be less important factors affecting P adsorption.
Volume 8, Issue 4 (Number 4 - 2006)
Abstract
Application of phosphorus (P) fertilizers as solid or liquid fertilizers to soils leads to re-actions of orthophosphate ions with various soil components which remove P from the so-lution phase and convert it to less soluble phosphates. This study was aimed at determin-ing soil properties that affect the rate of phosphate retention in 28 contrasting calcareous soils from different geographical regions (14 soils from Western Azarbaijan in Iran (WAI) and 14 soils from Western Australia in Australia (WAA). The results showed that the mean apparent recoveries of applied available P (Olsen P-based recovery) after 160 d of incubation at field capacity was found to be 7% for the soils of WAI and 25% for the soils of WAA. A study of correlation coefficients showed that, for the soils of WAA, there was a negative relationship between the recovery of applied P and the clay content (r = -0.59, P≤ 0.05), whereas there was a positive relationship between the recovery of P and the active CaCO3 (ACCE) content (r = 0.64, P ≤ 0.01). For the soils of WAI, there was a negative correlation between the Olsen P-based recovery and the clay content (r = -0.61, P ≤ 0.01). The decline in extractable P with time was best fitted to a second order kinetic equation. The kinetic rate constant (k) ranged from 0.092 to 0.55 mg kg-1d-1 for the soils of WAI and from 0.31 to 0.92 mg kg-1d-1 for the soils of WAA. The kinetic rate constant (k) increased with increasing the ratio of the clay content to ACCE for all soils of WAI. A re-gression analysis study showed that the ratio of clay/ACCE was the major factor govern-ing P retention.
Volume 9, Issue 2 (Number 2 - 2007)
Abstract
Pod length is one of the effective components on canola yield selection on the basis of which can increase not only the seed yield but also the oil yield. Molecular markers asso-ciated with long pod loci were identified in a doubled haploid population derived from a cross between the canola lines ‘Quantum’ (long pod) ‘China A’ (short pod) using RAPD and bulked segregant analysis. A molecular marker linkage map of 37 loci for this popu-lation was used to identify quantitative trait loci (QTL) controlling pod length of which two markers in two unlinked loci were selected by using an interval mapping model which explained 22% of phenotypic variation for pod length in this population. Selection for markers at two loci for increasing pod length resulted in a group of doubled haploid lines with an average 112 mm pod length that increased 15% of whole population mean. This shows that using these markers in the breeding program will enhance the breeding of long pod canola varieties.
Volume 9, Issue 2 (Spring 2021)
Abstract
Aims: This study was performed to investigate the relationship between ecological species groups and environmental factors in Fandoghlou rangelands of Ardabil province in the northwest of Iran, assuming that plant species distribution has been correlated with various of complex environmental gradients.
Materials & Methods: Data were collected from 180 sampling plots (1m2) in an area of 3.27km2 using the systematic-random method. In each plot, environmental factors (topography, climate, and soil variables) and the percent of vegetation cover for each species were recorded. TWINSPAN method and Canonical Correspondence Analysis (CCA) were used to define ecological species groups and determine the relationship between ecological species groups and environmental factors, respectively.
Findings: Results of using TWINSPAN for 180 plots classified rangeland communities into three groups. The first group contained 110 plots, the second group 40 plots, and the third group 30 plots. Using ISA, vegetation species groups in the first group contained 8 species, the second group 11 species, and the third group 8 species. In each group, the name of the species with the highest index value was selected as the group's name. Thus using CCA, the group of Trifolium pratense had a relation with aspect, slope, organic matter, magnesium, temperature, and volumetric soil moisture. The Leucanthemum vulgare was related to phosphorus, elevation, lime, sand, clay, and potassium. The group of Trifolium repense had a relation with pH, electrical conductivity, calcium, diffusible clay, temperature, silt, and sodium. The factors of diffusible clay and electrical conductivity with the first CCA axis and potassium and phosphorus factors with the second CCA axis had the strongest correlations.
Conclusion: Using the results of this study, we can evaluate the habitat conditions and vegetation quality of Fandoghlou rangelands. Moreover, used high-quality rangeland species such as Trifolium to counteract the spread of invasive species such as Leucanthemum vulgare.
Materials & Methods: Data were collected from 180 sampling plots (1m2) in an area of 3.27km2 using the systematic-random method. In each plot, environmental factors (topography, climate, and soil variables) and the percent of vegetation cover for each species were recorded. TWINSPAN method and Canonical Correspondence Analysis (CCA) were used to define ecological species groups and determine the relationship between ecological species groups and environmental factors, respectively.
Findings: Results of using TWINSPAN for 180 plots classified rangeland communities into three groups. The first group contained 110 plots, the second group 40 plots, and the third group 30 plots. Using ISA, vegetation species groups in the first group contained 8 species, the second group 11 species, and the third group 8 species. In each group, the name of the species with the highest index value was selected as the group's name. Thus using CCA, the group of Trifolium pratense had a relation with aspect, slope, organic matter, magnesium, temperature, and volumetric soil moisture. The Leucanthemum vulgare was related to phosphorus, elevation, lime, sand, clay, and potassium. The group of Trifolium repense had a relation with pH, electrical conductivity, calcium, diffusible clay, temperature, silt, and sodium. The factors of diffusible clay and electrical conductivity with the first CCA axis and potassium and phosphorus factors with the second CCA axis had the strongest correlations.
Conclusion: Using the results of this study, we can evaluate the habitat conditions and vegetation quality of Fandoghlou rangelands. Moreover, used high-quality rangeland species such as Trifolium to counteract the spread of invasive species such as Leucanthemum vulgare.
Volume 9, Issue 2 (Spring 2021)
Abstract
Aims: Most rangelands of Urmia in Iran have been destroyed and need significant restoration to achieve favorable conditions. This study aimed to investigate the impacts of a 19-years research exclosure on vegetation and soil features in Mahabad Sabzepoush rangelands of Iran.
Methods: To conduct research using the random-systematic method, three reference sites inside the exclosure and three reference sites outside the exclosure were selected with similar conditions. In each site, three linear transects, and along each transect, ten plots of one square meter were established. The percentage of canopy cover and the number of plants in each plot were measured using estimation and counting methods. From the beginning, middle, and end of each transect, soil samples were collected from a depth of 30 cm. An independent t-test was used to compare data on quantitative vegetation factors, land surface cover, richness characteristics, species diversity, evenness, and soil characteristics both inside and outside the enclosure.
Findings: Based on the results, 75 species belonging to 60 genera and 19 families were identified in the selected sites. Results showed that vegetation factors such as density and canopy cover of forbs and grasses and total canopy cover had a significant difference between the outside and inside of exclosure (p<0.05). The total density, density, and canopy cover of shrubs were not significantly different between exclosure and control sites (p>0.05). In the grazing area, the value of plant density of forbs, grasses, and shrubs was 43.84, 40.62, and 1.10number/m2, respectively. After 19 years of the exclosure, the forbs' density (57.45number/m2) and shrubs (2.17number/m2) were increased. Besides, forbs canopy cover increased from 18.14 to 24.88 (percentage) and shrubs canopy cover increased from 0.91 to 0.97% in 19 years exclosure. Richness, diversity, and evenness did not differ significantly between the exclosure and open grazing sites (p>0.05). The richness and diversity index was increased by 0.03 and 0.05 in the exclosure sites, but the evenness index increased by 0.01 in the open grazing sites. Nitrogen, electrical conductivity (EC), available phosphorus, organic matter, silt, and potassium in the exclosure and open grazing areas, had a significant difference (p<0.05). In the grazing area, EC and potassium's value was 1.35ds/m and 464.24ppm, respectively. After 19 years of the exclosure, the value of EC (1.10ds/m) and potassium (464.24ppm) were increased. Nevertheless, the values of other factors were decreased.
Conclusion: Although exclosure has increased the percentage of canopy cover, density, and diversity of species, but in some cases, non-observance of exclusion will prevent the achievement of the expected goals and desired results. These results indicate that grazing exclosure plays a crucial role in vegetation recovery and soil protection of destroyed rangelands.
Methods: To conduct research using the random-systematic method, three reference sites inside the exclosure and three reference sites outside the exclosure were selected with similar conditions. In each site, three linear transects, and along each transect, ten plots of one square meter were established. The percentage of canopy cover and the number of plants in each plot were measured using estimation and counting methods. From the beginning, middle, and end of each transect, soil samples were collected from a depth of 30 cm. An independent t-test was used to compare data on quantitative vegetation factors, land surface cover, richness characteristics, species diversity, evenness, and soil characteristics both inside and outside the enclosure.
Findings: Based on the results, 75 species belonging to 60 genera and 19 families were identified in the selected sites. Results showed that vegetation factors such as density and canopy cover of forbs and grasses and total canopy cover had a significant difference between the outside and inside of exclosure (p<0.05). The total density, density, and canopy cover of shrubs were not significantly different between exclosure and control sites (p>0.05). In the grazing area, the value of plant density of forbs, grasses, and shrubs was 43.84, 40.62, and 1.10number/m2, respectively. After 19 years of the exclosure, the forbs' density (57.45number/m2) and shrubs (2.17number/m2) were increased. Besides, forbs canopy cover increased from 18.14 to 24.88 (percentage) and shrubs canopy cover increased from 0.91 to 0.97% in 19 years exclosure. Richness, diversity, and evenness did not differ significantly between the exclosure and open grazing sites (p>0.05). The richness and diversity index was increased by 0.03 and 0.05 in the exclosure sites, but the evenness index increased by 0.01 in the open grazing sites. Nitrogen, electrical conductivity (EC), available phosphorus, organic matter, silt, and potassium in the exclosure and open grazing areas, had a significant difference (p<0.05). In the grazing area, EC and potassium's value was 1.35ds/m and 464.24ppm, respectively. After 19 years of the exclosure, the value of EC (1.10ds/m) and potassium (464.24ppm) were increased. Nevertheless, the values of other factors were decreased.
Conclusion: Although exclosure has increased the percentage of canopy cover, density, and diversity of species, but in some cases, non-observance of exclusion will prevent the achievement of the expected goals and desired results. These results indicate that grazing exclosure plays a crucial role in vegetation recovery and soil protection of destroyed rangelands.
Volume 10, Issue 1 (5-2010)
Abstract
The effect of aluminium content on the precipitation of in rapidly quenched Ni-Al binary alloys was investigated. Microstructural analyses of annealed and quenched samples indicate a transition from uniform to bimodal phase distribution in the composition range between 15.3 and 17.5 at.%Al. This transition is accompanied by changes in the morphology of precipitates. The microstructural observations are discussed in view of both kinetic and crystallographic considerations.
Volume 10, Issue 2 (Fall & Winter 2006)
Abstract
Operation manner in most of the conventional classification algorithms in remote sensing is based on pixels spectral information.Classification of these data ignore information obtained from adjacent pixels. In additional to with increasing of spatial resolution in satellites , increase harmful information( noise) and spectral similarity between classes , consequently increase internal variance of classes and finally decrease classification accuracy. To remove or decrease this problems , the proper incorporation and use of spectral and contextual information can efficiently help distinguish land-uses which are similar spectrally. In this study, effectiveness of incorporating structural information with classification procedures have been investigated. The technique is based on the use of edge-density information generated from the classified data. “ Maximum Likelihood ”(ML) , “ Minimum Distance to Means ”(MD) and “ Mahalanobis ” classification procedures have been used to classify data together with the edge-density information as an additional band. The performance of using edge-density data has been evaluated using the data of SPOT-XS and aerial photographs of the Anzali Wetlands ( Anzali Talab ) located in Gilan province north of Iran. This region is very heterogeneous. Results show that use of the structural information leads to increases in accuracy of some classes particularly those with low spectral separabilities. Mahalanobis classifier using spatial and spectral information in rural-urban ( 74.60) and river and channel ( 66.87) classes show 14.06 and 6.57 percent increases respectively in accuracies as compared to the spectral classification of satellite data. Application of this approach also in aerial photographs for patches of trees , river , agricultural and residential classes show 11.78 , 36.61 , 28.09 and 53.29 percent increases in accuracies respectively. Result show that considering the complex environmental conditions of the study site, the proper incorporation and use of spectral and spatial information can result in more efficient discrimination of some spectrally similar classes. The information of edge-density seems to be more promising in high resolution imagery and heterogeneous classes such as urban features.