مهندسی دریا
hossein bahrami; Mehdi Ghomshi; Seyed Mahmoud kashefi por; Seyed Ali Akbar Salehi Neyshabouri
Abstract
It is well known that the shortage of water is one of the most serious problems that faces the mankind. Therefore the study and search for the phenomenon that have impact on the water reservoirs and other natural resources of water, is essential. One of the most fundamental phenomenons relating to water ...
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It is well known that the shortage of water is one of the most serious problems that faces the mankind. Therefore the study and search for the phenomenon that have impact on the water reservoirs and other natural resources of water, is essential. One of the most fundamental phenomenons relating to water reservoirs is the density currents. The importance of the investigation and analysis of the hydraulic behavior of density currents will be apparent when we consider the consequences of the occurrence of these currents and its effects on the erosion of water reservoirs and also the sediments that they cause to be deposited in these reservoirs. For example the incoming of these currents in water reservoirs will effect the biological activities, it may cause sediments in these water reservoirs or it might press down these sediments to the bottom of water reservoirs.
علوم انسانی دریا
Abolfazl Darvishi; Morteza Dousti; Behzad Bagherian
Abstract
The aim of this study was to investigate the political obstacles to the development of sports tourism coastal in the mazandaran province. This research method was mixed. The statistical population consisted of officials of the province governor, gubernatorial, department of sport and youth as well as ...
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The aim of this study was to investigate the political obstacles to the development of sports tourism coastal in the mazandaran province. This research method was mixed. The statistical population consisted of officials of the province governor, gubernatorial, department of sport and youth as well as officials in the coastal lifeguards and the sampling method was purposive available sampling. In the qualitative section, obstacles were identified by using semi-structured interviews with a sample (n = 18) and interviews stopped after the theoretical saturation. In the quantitative section the findings from the interviews the form of a questionnaire survey were distributed and collected among 384 individuals. The validity and reliability of qualitative section examined by member’s review and re-coding ways. Face validity and content validity of the questionnaire was conducted by experts and factor analysis (KMO=0.8). The reliability of the questionnaire was assessed by Cronbach's alpha (=α0.83). To analyze the interviews was used of Grounded Theory and using the open coding, axial coding and selective coding. In the quantitative section data analysis was used descriptive and inferential statistics (Friedman test). The Findings revealed that lack of appropriate legislation to protect coastal sports tourism, lack of coordination between the various entities concerned, official duties unclear in different parts of the decision-maker and lack of strategic plans and acts of individual taste some of those involved in the development of sports tourism coastal was as the most important obstacles from the perspective of the respondents. .
علوم زیستی دریا
negar fadian behbahani; foad buazar
Abstract
Recently, there is a growing necessity to develop environmentally friendly nanoparticle synthesis methods .In this study, we have investigated synthesis of magnetic iron nanoparticles using Sargassum ilicifolium alcoholic extract. The synthesis and characterization of magnetic iron nanoparticles were ...
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Recently, there is a growing necessity to develop environmentally friendly nanoparticle synthesis methods .In this study, we have investigated synthesis of magnetic iron nanoparticles using Sargassum ilicifolium alcoholic extract. The synthesis and characterization of magnetic iron nanoparticles were obtained via UV-Vis spectrum , X-ray diffraction(XRD), transmission electron microscopy(TEM) and vibrating sample magnetometry(VSM) respectively. Formation of iron nanoparticle was attended whit change color from green to green brownish. The maximum peak absorption of synthesized iron nanoparticles was observed at 428 nm indicating the reduction of iron ions and formation of iron nanoparticles. According to the acquired analyses, shape of nanoparticles was spherical and face centered cubic(FCC) and the crystal size was 26.73 nm. Moreover, as prepared iron nanoparticles were demonstrated superparamagnetic and soft magnetic properties.
علوم زیستی دریا
Sahebali Ghorbani; Davod Talebi Haghighi; Hassan Maghsoodieh Kohan; Sayed Muhammad Salavatian; Daryoush Parvaneh Moghadam
Abstract
Experiment were conducted to evaluate the effects of different dietary levels of fat (%8,%12,%16,%20) on growth of Roach Caspian sea (Rutilus rutilus caspicus) fingerling in four treatments with triplicates. Fish averaged 5.30 gr stoking density of 15 fish/tank in a during of 67 days which reared into ...
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Experiment were conducted to evaluate the effects of different dietary levels of fat (%8,%12,%16,%20) on growth of Roach Caspian sea (Rutilus rutilus caspicus) fingerling in four treatments with triplicates. Fish averaged 5.30 gr stoking density of 15 fish/tank in a during of 67 days which reared into 100L-fiber glass tanks. At the end of experiment, was calculated growth parameters, such as weight gain(%), specific growth rate, food conversion ratio, condition factor and survival (%) but the statistical analysis not shoed significantly different among all treatments (p>0/05). In this experiment, whole-body protein, lipid and ash contents of fish fed the different dietary lipid levels indicated that significant difference among of treatments. The study revealed that fingerlings of Roach Caspian sea showed highest growth performance when fed diet containing 16%
مهندسی دریا
Meysam Salarijazi
Abstract
Estimation of the water level in river’s tidal limit is a suitable tool for the tidal flood management for rivers that are located in coastal areas. In this limit, propagation of tidal waves along the river to the upstream and combination of these waves and upstream flood discharge leads to an ...
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Estimation of the water level in river’s tidal limit is a suitable tool for the tidal flood management for rivers that are located in coastal areas. In this limit, propagation of tidal waves along the river to the upstream and combination of these waves and upstream flood discharge leads to an increase in flood plain limit and risk of damage. In this study, the reach between Ahvaz and Khorramshahr in Karun River is selected as case study and different linear and non-linear models are investigated for prediction of water level as a function of flood discharge of upstream. The analysis is performed for two cases considering the nature of tidal flood. In first case, total recorded data is investigated while in second case tidal flood data is extracted based on peak over threshold series analysis. Analysis of residuals of models in two cases show that the linear models are not acceptable, therefore the transformed nonlinear models that are a form of linear models are considered for modeling too. The power equations with improved coefficient of determination, relatively constant variance and normal distribution of residuals of models are concluded from detailed analysis in calibration parts for two cases. These selected models are used for validation part for two cases. The results confirm the acceptability of these models considering their simplicity and better efficiency for first case than second case.
مهندسی دریا
Morteza Bakhtiari; Shahriyar Shemshaki; Masoud Sadri nasab
Abstract
With the advent of technology and the expansion of human needs, the use of water platforms such as seas, oceans, and the recognition of methods and solutions for the design and implementation of marine structures is becoming increasingly clear.The semi-submerged platform is one of a variety of submarine ...
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With the advent of technology and the expansion of human needs, the use of water platforms such as seas, oceans, and the recognition of methods and solutions for the design and implementation of marine structures is becoming increasingly clear.The semi-submerged platform is one of a variety of submarine platform platforms, which, according to the features of the platform, is mainly used for extracting deep-sea oil and gas resources. In this research a semi- submersible platform under performance condition using ANSYS finite element software is numerical modeling and It is under regular waves. The platform's geometry is based on a platform built in 2012, and the data used in this study is about the average 20 years of Caspian waves.The degree of displacement, rotation, and force of diffusion has been obtained in degrees of freedom and are compared with each other. to apply regular waves Airy theory has been used. The result of this study show that In the loading of regular waves, the two parameters of the wave period and the wave propagation angle were the determining factor in the displacement and the platform time, as well as the dispersion force resulting from the collision of the wave with the platform. Also, the results show that at a 90 degree angle of the wave with the platform, the motion state at 2 degrees Z, Ry was close to zero and was the largest amount of time around the X axis.