S. A. R. Hashemi; S. A. Taghavimotlagh; R. Ghorbani; A. Hedayati
Volume 3, Issue 1 , March 2013, , Pages 1-6
Abstract
During this study from December 2009 to November 2011, 363Deep flounder fish were caught and their weight and length were measured. The caught fish included 18 males, 200 females and 155 immature fishes. The mean, maximum and minimum total lengths were 264 ± 57 (mean ± SD), 415 mm and 115 ...
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During this study from December 2009 to November 2011, 363Deep flounder fish were caught and their weight and length were measured. The caught fish included 18 males, 200 females and 155 immature fishes. The mean, maximum and minimum total lengths were 264 ± 57 (mean ± SD), 415 mm and 115 mm respectively. The mean, maximum, and minimum total weights for this species were 238 ± 150 g, 827 g and 14 g respectively. The calculated length-weight relationships were W=0.000007FL3.09 (n=200, R2= 0.96) for the female, W=0.00002FL2.90 (n=18, R2=0.94) for the male and W=0.000009FL3.04 (n=363, R2 =0.96) for total fish. With a verified calculated b as 3 Student t-test showed no significant difference between calculated b and 3 (P>0.05), demonstrating that the growth pattern is isometric. Population parameters calculated for total fish were L∞= 42 (cm); K= 1 (year-1); t0= -0.14 and Ф’= 3.24. Based on the results, this species is classified as mediate vulnerable group fish.
M. Kasaeyan; J. Wang; I. Jenkinson; M. R. Miri Lavasani
Volume 1, Issue 1 , December 2011, , Pages 3-12
Abstract
The traditional event tree analysis uses a single probability to represent each top event. However, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. The fuzzy set theory is universally applied to ...
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The traditional event tree analysis uses a single probability to represent each top event. However, it is unrealistic to evaluate the occurrence of each event by using a crisp value without considering the inherent uncertainty and imprecision a state has. The fuzzy set theory is universally applied to deal with this kind of phenomena. The main purpose of this study is to construct an easy method to evaluate human errors and integrate them into event tree analysis by using fuzzy concepts. A systematic fuzzy event tree analysis algorithm is developed to evaluate the risk of a largescale system. A practical example in of offshore oil pipeline is used to demonstrate this procedure.
A. Koochekali; B. Gatmiri; A. A. Koochekali
Volume 3, Issue 2 , June 2013, , Pages 43-50
Abstract
Offshore pipelines used for oil and gas transportation are often buried to avoid damage from fishing activities and to provide thermal insulation. Thermal expansion and contraction of the pipeline during operation can lead to lateral or upheaval buckling. A safe buried pipeline design must take into ...
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Offshore pipelines used for oil and gas transportation are often buried to avoid damage from fishing activities and to provide thermal insulation. Thermal expansion and contraction of the pipeline during operation can lead to lateral or upheaval buckling. A safe buried pipeline design must take into account a reliable evaluation of soil uplift resistance and pipe embedment depth. While the cost of burying a pipeline for tens or hundreds of kilometer is significant, it is important to optimize the required soil cover depth. In this paper a parametric study of pipeline upheaval buckling in clayey backfill has been conducted using finite element analysis. Three different embedment depths are considered. Uplift resistance is calculated and failure mechanism is obtained. To simulate the large penetration of the pipe into clayey backfill a novel Arbitrary Lagrangian Eulerian (ALE) finite element technique was employed in this paper. The results reveal that as embedment depth increases, uplift resistance increases and also uplift mechanism changes. However, uplift resistance differ less than 5% for deep embedment case. In addition, the amount of pore pressure is investigated beneath the pipe for deep embedment cases and it reveals that negative excess pore pressure occurs under the pipeline.
S.A. Amid; S. Allahyaribeik
Volume 5, Issue 2 , June 2015, , Pages 55-64
Abstract
Steel-structured jacket or template platforms have been extensively installed in Persian Gulf offshore oil & gas fields. For the jackets in the water depth range of 40 meters in this region, utilizing the self-upending concept has been investigated. It has been concluded that designing the light ...
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Steel-structured jacket or template platforms have been extensively installed in Persian Gulf offshore oil & gas fields. For the jackets in the water depth range of 40 meters in this region, utilizing the self-upending concept has been investigated. It has been concluded that designing the light weight jackets, implementing the self-upending process for their installation operations, are economically and practically more convenient than the usual crane-assisted up-ending methods. Two methods of self-upending for light weight jackets have been presented in this paper .in first method self-upending is implemented without using ballast systems and in second model self-upending is implemented with ballast systems .Considering the required number of new installations for the “new” as well as “brown-bag” projects, and considering the existing problems and difficulties for the available marine spread, especially ready-to-work heavy floating cranes, utilizing this concept in the offshore industry for light weight jackets seems to be a considerable break-through
A. Biati; H. Nikoomaram; A. R. Karbassi
Volume 2, Issue 1 , March 2012, , Pages 75-80
Abstract
Since heavy metals are considered as one of the major pollutants threatening, the main goal of this study was to bring out the concentrations of Pb, Zn and Mn in the surface sediments off Bushehr in the Persian Gulf. For this purpose, after collection of samples, the concentrations of the three metals ...
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Since heavy metals are considered as one of the major pollutants threatening, the main goal of this study was to bring out the concentrations of Pb, Zn and Mn in the surface sediments off Bushehr in the Persian Gulf. For this purpose, after collection of samples, the concentrations of the three metals in surface sediments were measured through the atomic absorption. The results were compared with the mean of the elemental concentrations of Earth’s crust, world’s sediments and other areas of the Persian Gulf. Although the mean of concentrations in selected stations were higher than the Persian Gulf’s central section, in comparison with Earth’s crust and world’s sediments, it was revealed that the concentrations of Zn and Mn were much lower. Moreover, cluster analysis showed that the two elements, Zn and Mn, had the same behavior and the concentration of Pb was not changed by depth increase.
Volume 3, Issue 3 , July 2013, , Pages 105-112
Abstract
Analyzing the vortex-induced vibration of a slender marine structure withlength to diameter ratio up to 200 is the objective of this study. This slender is free to move in both in-line and cross flow directions and immersed completely in water. Three different types of shear currents pass on it and cause ...
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Analyzing the vortex-induced vibration of a slender marine structure withlength to diameter ratio up to 200 is the objective of this study. This slender is free to move in both in-line and cross flow directions and immersed completely in water. Three different types of shear currents pass on it and cause to vibrate slender in different forms. Nowadays, these vibrations are very important for designers. In this study, 3D Finite difference method has been used to solve cable governing equations in a long slender with two hanged ends. The hydrodynamic forces, in the direction of in-line and cross-flow created by vortex shedding are simultaneously considered based on Morison equation. In a specified range of Reynolds number, the flow is in-line direction, but the results show riser oscillation in both in-line and cross flow directions. The results showed a good agreement with other researches in VIV with constant flow on it. Then non-uniform flows with profiles in real ocean currents were selected as inputs of this study. The results showed that small variations in velocity profiles and quantities can create significant differences in riser behavior.
M. Ghodsi Hasanabad
Volume 2, Issue 2 , June 2012, , Pages 135-140
Abstract
In this study, boundary element method was used to model sea wave propagation on a hemisphere shape under water tank and oil-water common surface oscillation in the tank. Also, kinematic and dynamic oundary conditions of free surface and common surface of oil and water were discritized by Finite ...
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In this study, boundary element method was used to model sea wave propagation on a hemisphere shape under water tank and oil-water common surface oscillation in the tank. Also, kinematic and dynamic oundary conditions of free surface and common surface of oil and water were discritized by Finite difference method. There were some singularities in BEM method, which were removed by applying zoning method. The wave specifications and water depths, which were entered in numerical model, were extracted from Geographic and climatic profiles of Abuzar oil field region in Persian Gulf. The results show an acceptable accordance with ther researches. Also, the results illustrated that, using open ended storage tanks near our offshore platforms has not any problem and it can be a good proposal for oil storing by considering their advantages.
M. Ghodsi Hasanabad
Volume 2, Issue 3 , August 2012, , Pages 177-184
Abstract
Free surface modeling plays an important role in some ocean structures design, especially in Oscillating Water Column (OWC) devices. Boundary element method (BEM) is a suitable method for free surface modeling due to its simplicity, quick solving, and low data storage requirement. In this paper, BEM ...
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Free surface modeling plays an important role in some ocean structures design, especially in Oscillating Water Column (OWC) devices. Boundary element method (BEM) is a suitable method for free surface modeling due to its simplicity, quick solving, and low data storage requirement. In this paper, BEM was used for free surface modeling in OWC chamber and out of it. Linear kinematic and dynamic boundary conditions were used for free surface out of OWC chamber and nonlinear forms were used for free surface in the hamber. These boundary conditions were descritized by finite differences method (FDM). Also, some thermodynamics relations were applied for trapped air behavior modeling in OWC chamber. Wave specifications in Chabahar region due to its high power waves entered in programming code as input data. The results show a good agreement with results of other researches. Also, it is concluded that Iranian sea waves have no good potential for use ordinary OWC devices, because, a little power (about 10 KW) can be extracted from an OWC, in the best point.
S. Eskandari; H. Mozdarani; A. Mashinchian Moradi; M. H. Shahhosseiny
Volume 2, Issue 4 , December 2012, , Pages 215-224
Abstract
Crude oil is enriched in polycyclic aromatic hydrocarbons (PAHs). Many PAH analogs have proved to potentially damage DNA. DNA damage can be assessed using various biomarkers to find out the degree of genotoxicity of pollutants following in vitro exposure. In this research the comet assay and micronucleus ...
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Crude oil is enriched in polycyclic aromatic hydrocarbons (PAHs). Many PAH analogs have proved to potentially damage DNA. DNA damage can be assessed using various biomarkers to find out the degree of genotoxicity of pollutants following in vitro exposure. In this research the comet assay and micronucleus (MN) test were used to detect DNA damages and cytogenetic changes following crude oil exposure. For this purpose, freshwater bivalve mollusks (Anodonta cygnea) were exposed for ten days to 0.25, 0.5 and 1.0 ppm of crude oil. For the comet assay and for the MN test, hemolymph and gill cells of mussels were sampled respectively. Statistically, significant increase of DNA damage and micronuclei were found with 0.25, 0.5 and 1.0 ppm of crude oil. This study was performed to ascertain that A. cygnea is a good bioindicator of pollutants in aquatic environments; also identified hemolymph and gill of A.cygnea are most effective and practical tissues for genotoxicity studies.
sara allahyaribeik; madjid abbaspour; amir hossein javid
Volume 4, Issue 1 , February 2014, , Pages 1-6
Abstract
The use of acoustic waves in researches related to sea water is of most importance among scientists recently. Since these waves are the only waves, transmitted in water with lowest attenuation and high speed, they can be used in many scientific fields. The main goal of this research is to better understand ...
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The use of acoustic waves in researches related to sea water is of most importance among scientists recently. Since these waves are the only waves, transmitted in water with lowest attenuation and high speed, they can be used in many scientific fields. The main goal of this research is to better understand the physics and mechanisms of sound-seabed interaction, including acoustic penetration, propagation, attenuation and scattering in marine sediments using a laboratory study approach. Sound backscattering from water sediments at central frequencies 1,2.25,5,10 and 15 MHz was studied in controlled laboratory conditions. Six kinds of sediments, from very coarse sands to fine sands, were degassed, and their surface was flattened. In these conditions, the sediment granular structure can be considered as the only controlling mechanism of backscattering. Comparison of frequency dependencies of backscatter for the six sediments with different mean grain sizes shows that in which frequencies we have the maximum backscattering sensitivity to the sediment mean grain diameter, and frequency-dependent attenuation will be shown.
V. Zarepoor; E. Ezam; S Allahyaribeik
Volume 5, Issue 1 , January 2015, , Pages 1-13
Abstract
Thermocline layer have remarkable effects on acoustic propagation in Persian Gulf environment. So far, no comprehensive research has been conducted to explore thermocline layer, especially its characteristics including top, thickness, and thermal gradient of thermocline in Persian Gulf. Besides, effects ...
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Thermocline layer have remarkable effects on acoustic propagation in Persian Gulf environment. So far, no comprehensive research has been conducted to explore thermocline layer, especially its characteristics including top, thickness, and thermal gradient of thermocline in Persian Gulf. Besides, effects of thermocline on underwater acoustic propagation including transmission loss and sound channel formation in Persian Gulf have not been investigated as most studies to date have focused on the effect of thermocline on transmission loss in low frequencies, while high frequencies have been studied less. Accordingly, this study attempts to shed light on these ambiguities. ROPMI Cruise measurement data collected during summer (August) of 2001 in Persian Gulf were used in this study. To simulate the acoustic propagation, ray-tracing theory was also applied to make possible an analysis of high frequencies. Results showed that presence of thermocline layer have remarkable effects on transmission loss. Increasing the gradient in thermocline layer will raise transmission loss.
A. MashinchianMoradi; M. Pirouznezhad
Volume 3, Issue 1 , March 2013, , Pages 7-12
Abstract
The present study was carried out in 2011 to measure concentration of heavy metals chromium and tin in liver and muscle tissue of Liza aurata (golden grey mullet) in estuaries of the rivers Babolroud, Tajan and Gorganroud. Accordingly, after sampling the target are asandisolating muscle (18samples) and ...
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The present study was carried out in 2011 to measure concentration of heavy metals chromium and tin in liver and muscle tissue of Liza aurata (golden grey mullet) in estuaries of the rivers Babolroud, Tajan and Gorganroud. Accordingly, after sampling the target are asandisolating muscle (18samples) and liver (18samples) tissues, they were digested and analyzed using Graphite Furnace Atomic Absorption Spectrometer (GFAAS). Then, the obtained data were analyzed statistically using Spss19. The results indicated that the concentration of the metals in liver was higher than the muscle tissue. The highest concentration was related to the tin metal in liver tissue of the golden grey mullet measured from Gorganroud Area while the lowest concentration was related to chromium reported from the estuary of Tajan River. Asignificant difference (P<0.05) was observed between the concentrations of chromium metal in liver and muscle tissue. No significant difference was recorded between the concentrations of tin metal in liver and muscletissue of golden grey mullet (P>0.05). At the end, relationship between weight, length and average concentration of tin and chromium in liver and muscle tissue of golden grey mullet were analyzed by Pearson'stest. A significant reverse linear correlation wasfound between concentration of tin and the weight (p<0.05).
A. A. Bidokhti; A. Shekarbaghani
Volume 1, Issue 1 , December 2011, , Pages 13-22
Abstract
Ocean waters often show layered structures especially where exchange flow between two basins occurs. These structures are often attributed to processes such as double.diffusive convection, internal waves, turbulent modulated mixing. In this paper by examining the vertical structures of temperature, salinity ...
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Ocean waters often show layered structures especially where exchange flow between two basins occurs. These structures are often attributed to processes such as double.diffusive convection, internal waves, turbulent modulated mixing. In this paper by examining the vertical structures of temperature, salinity and density, of the middle parts of Caspian Sea it is shown that such layered structure may be due to the normal modes of the internal waves as double diffusive convection (the density ratio is often negative) does not often occur in these waters. Contours of isotherm, isohaline and isopycnal show the existence of rather regular wavy structures, which may indicate that internal waves, which are produced of exchange, flow between two basins; as a result of horizontal density gradients (usually from middle basin to southern basin) may generate these layers. The flow velocity associated with this gravity driven flow is about 0.1 to 0.15 m/s which gives a Froude number of about one. The wave lengths of these wavy structures are about 200 km and hence, the frequencies of them are of order of inertial frequency at these latitudes. The normal modes of these waves appear to have a near steady structure and can fold the inflow front from the Northern
part of the Caspian Sea to the Southern deep basin. The thickness of formed layers is found be about 10-20 m which is
in agreement with the values predicted by the model of
Wong et al. (2001)
and is less likely to be produced by double
diffusive convection as the density ratio is often not appropriate for this process.
A. R. Bakhtiari; M. Fathi Moghadam
Volume 3, Issue 2 , June 2013, , Pages 51-56
Abstract
This paper presents an experimental study the influence of wave parameter on the damage of reshaping seawall, model tests have been performed in several water level conditions. The experiments of physical modeling of this research have been done in the flume of the Soil Conservation and Watershed Management ...
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This paper presents an experimental study the influence of wave parameter on the damage of reshaping seawall, model tests have been performed in several water level conditions. The experiments of physical modeling of this research have been done in the flume of the Soil Conservation and Watershed Management Research Institute (SCWMRI). The waves applied to the structure model are irregular and the energy spectrum of the applied waves is JONSWAP. The material of arm our layer have been regarded with the scale of 1:25 model and grading class of D85/D15=1.82. A number of 3000 waves were applied on the structure over the research in general and some 60 experiments have been totally accomplished. The results of tests after drawing graphs, has been analyzed. That it can be harvested with %82 increasing in wave steepness, damage parameter %85 decreased and also with %57 increasing in wave height, the damage parameter %87 increases and with %57 increasing in wave length, the damage will %83 increase.
P. . Atabak; S. Allahyaribeik; F. Azarsina
Volume 4, Issue 2 , June 2014, , Pages 57-64
Abstract
This study aims to examine the performance of the rock materials in the protective layer of rubble-mound breakwaters in southern Iran, from Rostami Port in Bushehr Province to Beris Port in Sistan and Baluchestan Province. Field inspections were carried out on a great number of rubble-mound breakwaters ...
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This study aims to examine the performance of the rock materials in the protective layer of rubble-mound breakwaters in southern Iran, from Rostami Port in Bushehr Province to Beris Port in Sistan and Baluchestan Province. Field inspections were carried out on a great number of rubble-mound breakwaters built in the Persian Gulf and Oman Sea coastal regions to study the protective layer of these breakwaters under ambient conditions as well as to detect the damage caused by factors affecting the failure of the used materials. Subsequently, samples were taken from these rock materials, the specimens were tested in accordance with various quality assessment criteria, and the results were compared with those obtained from international standard tests. The obtained results showed that in most cases, the physical and chemical properties of the local rock materials did not meet standard requirements. As such, these materials are not recommended for use in the construction of breakwaters. In practice, however, these rocks exhibit an acceptable performance in certain cases depending on the position of each rock group in the structure of the breakwater. For this reason, design, construction, and structural considerations can somehow influence the performance of these rock materials in the respective marine structures.
M. Soltaninejad; F. Azarsina; A.H. Javid
Volume 5, Issue 2 , June 2015, , Pages 65-75
Abstract
Many existing phenomena in nature are considered new design ideas in various fields of industry. Bionics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology. By performing bionic review, the researchers found the penguins ...
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Many existing phenomena in nature are considered new design ideas in various fields of industry. Bionics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology. By performing bionic review, the researchers found the penguins by delivering air locked under their wings and creating air bubbles, the drag significantly reduces. This motivates to study this factor in the marine industry by researchers and scientists. The overall drag of a marine vessel is directly proportional to the frictional drag. The reduction of frictional drag can be achieved by creating an air layer between vessel`s hull and flow around it. Creation of a cavity and cross channel of air can be easily just in order to reduce hull drag, while the air from a hole is injecting, the drag reduction up to 20 percent might be achieved. Experiments indicate that the pattern of wave drag reduces due to the air using and changes in pressure fields. In this research, by the use of theoretical relationships and the results of experiments, frictional drag reduction with different methods of air injection was investigated and then by the use of numerical software simulation (ANSYS-fluid flow), air injection on the floating model. The achieved results for drag reduction with decrease of wetted surface area at speeds of 4, 6 and 8 m/s are presented. By comparing the results of experiments(Harley high speed craft model) with software analysis and software simulation was validated. Due to high cost of manufacturing a model with air injection accessories and towing tank tests, with the acceptable precision results of this research, numerical software simulation (ANSYS-Fluid Flow) is more quick and efficient.
F. Shariati; A. Esmaili Sari; A. Mashinchian Moradi; M. Pourkazemi
Volume 2, Issue 1 , March 2012, , Pages 81-90
Abstract
Tissue metal accumulations (gills, liver, kidney and muscle) in Persian sturgeon (Acipenser persicus) were compared folowing exposure to sublethal levels of waterborne Cd (50, 400 and 1000 μg•L-1) after periods of 1, 2, 4 and 14 days. The obtained results indicate that at the end of 4 and 14 ...
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Tissue metal accumulations (gills, liver, kidney and muscle) in Persian sturgeon (Acipenser persicus) were compared folowing exposure to sublethal levels of waterborne Cd (50, 400 and 1000 μg•L-1) after periods of 1, 2, 4 and 14 days. The obtained results indicate that at the end of 4 and 14 days of exposure, total tissue cadmium concentration followed the pattern: liver > gill > kidney > muscle. Calculation of bioconcentration factor (BCF) after 14 days exposure showed that at low and high concentrations, highest BCFs were found in kidney and liver, respectively. According to the results, the accumulation capacity of muscle was the lowest at all exposure concentrations. Cd concentration in the cytosol of experimental tissues were measured and the results indicated that Cd levels in the cytosol of liver, kidney and gills increased 240.71, 32.05, and 40.16-fold, respectively 14 days after exposure to 1000 μgL-1 Cd. The accumulation of Cd in cytosol of tissues is in the order of liver> gills> kidney.
Volume 3, Issue 3 , July 2013, , Pages 113-124
Abstract
Seasonal variations of the seawater properties (e.g. temperature, salinity, density and chlorophyll-a) in western part of the southern coastal waters of the Caspian Sea near the Iranian coast were studied. A portable CTD probe was applied for profiling from sea surface to bottom at 23 stations. Maximum ...
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Seasonal variations of the seawater properties (e.g. temperature, salinity, density and chlorophyll-a) in western part of the southern coastal waters of the Caspian Sea near the Iranian coast were studied. A portable CTD probe was applied for profiling from sea surface to bottom at 23 stations. Maximum depth of the profiling stations was more than 470 m in the study area. Vertical structure of temperature in the southern Caspian Sea waters is characterized by a significant seasonal thermocline between 20-50 m depths in summer with a vertical gradient of 16 oC. Seasonal average of the salinity was in a range of 12.27-12.37 PSU in period of measurements. The data showed that the most chlorophyll-a was found below the sea surface. In general, variations of the chlorophyll-a concentration in the study area can be attributed to the effect of changes of seawater characteristics in various seasons, stratification and heating the sea surface layer in the warm seasons and discharge of lagoon and rivers in the study area. The range of the concentrations at the sea surface in August and November were higher than the measured values in April in the study area. Concentrations of chlorophyll-a were recorded in midsummer in a range of 0.2-3.4 mg m-3.
A. H. Javid; M. Abbaspour; S. A. Mirbagheri; H. JanfeshanAraghi
Volume 2, Issue 2 , June 2012, , Pages 141-148
Abstract
The study of wave and its propagation on the water surface is among significant phenomena in designing quay, marine and water structures. Therefore, in order to design structures which are exposed to direct wave forces, it is necessary to study and simulate water surface height and the wave ...
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The study of wave and its propagation on the water surface is among significant phenomena in designing quay, marine and water structures. Therefore, in order to design structures which are exposed to direct wave forces, it is necessary to study and simulate water surface height and the wave forces on the structures body in different boundary conditions. In this study, the propagation of static sinusoidal wave in deep water environment with complex boundary conditions are simulated by using Smoothed Particle Hydrodynamics (SPH) technique. The governing equations are programmed using VISUAL FORTRAN6.5 and the solution results are visualized using TECPLOT. After determining the suitable number of particles for simulation, the duration of sinusoidal wave oscillation are measured by simulation and are compared with analytical solution. After ensuring the accuracy and veracity of proposed SPH method in simulation of static sinusoidal wave motion on the deep water surface, the simulation are carried out in more complex boundary conditions which there are no analytical solutions.
A. Mashinchian Moradi; H. Mozdarani; P. Alidoust Salimi; M. Alidoust Salimi
Volume 2, Issue 3 , August 2012, , Pages 185-188
Abstract
Malathion (S-(1, 2-dicarboethoxyethyl) O, O-dimethyl phosphorodithioate) is one of the organophosphate pesticides comprehensively used in agriculture fields throughout the world. In spite of widely used, little information are available about DNA damage in aquatic organisms. Therefore, the present study ...
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Malathion (S-(1, 2-dicarboethoxyethyl) O, O-dimethyl phosphorodithioate) is one of the organophosphate pesticides comprehensively used in agriculture fields throughout the world. In spite of widely used, little information are available about DNA damage in aquatic organisms. Therefore, the present study carried out to investigation of DNA damage induced by malathion in Cyprinus carpio (Pisces: Cyprinidae) using single cell gel electrophoresis. The condition of experiment was determined in static system. The specimens were exposed to different non-lethal concentrations (0.5, 1.5 and 3 mgL-1) of the malathion for 96 hour (short-time exposed). Our results showed, the specimens exposed to different concentrations of malathion exhibited significantly higher DNA damage in their blood cells than the control sample (P<0.05). This study confirmed that the comet assay is useful method in determining genotoxicity of pesticides. Fish can be used for biomonitoring of the genotoxic pollutants in aquatic environment. Furthermore, DNA strand breakage can be used as biomarker in ecotoxicological studies.
S. Hamzehei; A.A. Bidokhti; M. S. Mortazavi; A. H. Gheiby
Volume 2, Issue 4 , December 2012, , Pages 225-232
Abstract
pollutions. Recently, both Persian Gulf and Gulf of Oman are experiencing several types of pollution including oil spills and heavy metal pollutions as well as Harmful Algal Bloom (HAB) caused by biological and environmental changes. Theiroccurrence of the red tide or harmful algal bloom during fall ...
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pollutions. Recently, both Persian Gulf and Gulf of Oman are experiencing several types of pollution including oil spills and heavy metal pollutions as well as Harmful Algal Bloom (HAB) caused by biological and environmental changes. Theiroccurrence of the red tide or harmful algal bloom during fall and winter 2008-2009 caused numerous unknown factors in the Strait of Hormuz, Persian Gulf and Gulf of Oman which left many destructive effects on fishery, aquaculture, tourism industry and environmental conditions of the region as some of them have not vanished absolutely yet. This paper deals with the analysis of application of the marine satellite imaging sensors to study and monitor the adverse environmental factors, particularly those associated with algal bloom occurred in 2008-2009. Data obtained by the MODIS sensors used to monitor the relevant environmental factors of the red tide. Our results showed that the occurred algal bloom was the result of seawater temperature drop, water circulation and the adverse environmental pollutions caused by industrial and urban sewages entering the coastal waters in this region of the Persian Gulf., This red tide phenomenon started in the Strait of Hormuz and eventually covered about 140,000 km2 of the Persian Gulf and total area of Strait of Hormuz. It survived for 9 months which is a record amongst the occurred algal blooms across the world.
vahid niksima; kamran lari; masoud torabiazad
Volume 4, Issue 1 , February 2014, , Pages 7-14
Abstract
Nowadays, in consideration of environmental issues and limitation of fossil fuels, there is a particular consideration of renewable energy including Ocean Energy, that can extracted going through various methods such as Wave Energy, Tidal Energy, Salinity Gradient, OTEC: Ocean Thermal Energy Conversion.Herein ...
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Nowadays, in consideration of environmental issues and limitation of fossil fuels, there is a particular consideration of renewable energy including Ocean Energy, that can extracted going through various methods such as Wave Energy, Tidal Energy, Salinity Gradient, OTEC: Ocean Thermal Energy Conversion.Herein this research, operation of OTEC Method in Southern Caspian Sea has been discussed. For this purpose Sea Surface Temperature (SST) Data and Thermocline diagram with respect to 25 stations from east to west coastal area, measured in 1995 in various seasons, have been used. Considering the researches conducted, in order to use OTEC, there must be a difference in temperature between the surface and depth for at least 20 Degrees Centigrade. If such difference in temperature occurs in less depth, closer to the coast, such energy extraction will be more cost-effective.According to investigations conducted, there is a difference in temperature for about 20 Degrees Centigrade in the depth of about 200 m in the Caspian Sea during hot seasons of the year. In summer and early autumn when Thermocline achieves its complete growth, energy extraction from OTEC has a desirable yield. During winter and spring when there is decay in Thermocline, the yield is so low that using this method is not justifiable. Thus, this method can only be used in hot seasons of the year. Finally, hydrographic and temperature investigations have revealed that southeastern coasts especially those of Bandar Neka and Babolsar achieve the desirable difference in temperature, closer to the coast due to high SST and coastal slope, compared to other areas and eventually, using OTECT is cost-effective.
N. Moayyeri; K. Saeb; E. Biazar
Volume 3, Issue 1 , March 2013, , Pages 13-16
Abstract
Heavy metals are highly poisonous in the environment, even in small quantities, and endanger certain species and all live beings. Current methods of removing heavy metals from aqueous media include chemical sequestration, ion exchange, surface absorption, membrane processes, oxidation and revival procedures ...
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Heavy metals are highly poisonous in the environment, even in small quantities, and endanger certain species and all live beings. Current methods of removing heavy metals from aqueous media include chemical sequestration, ion exchange, surface absorption, membrane processes, oxidation and revival procedures which have high investment and exploitation costs. Hence, it is significantly necessary to develop new and economical methods for effective removal of these metals from water and sewage. The present paper aims to evaluate efficiency of microparticles in removing heavy metals from water. Results of application of hydroxy-apatite microparticles as absorbers of heavy metals show that the absorption percentage average of lead (84.72%) by hydroxy-apatite microparticles is greater than that of cadmium (49.89%), zinc (72.90%), iron (74.50%) and nickel (79.25%).
M. Abdoli; F. Azarsina; M.H. Givian Rad
Volume 5, Issue 1 , January 2015, , Pages 15-21
Abstract
Today due to increasing development and importance of petroleum activities andmarine transport as well as due to the mining of seabed, building activities such as construction of docks, platforms and structures as those in coastal areas and oceans has increased significantly. Concrete strength as one ...
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Today due to increasing development and importance of petroleum activities andmarine transport as well as due to the mining of seabed, building activities such as construction of docks, platforms and structures as those in coastal areas and oceans has increased significantly. Concrete strength as one of the most important necessary parameters for designing, depends on many factors such as mixture plan ofconcrete, concrete forming materials, and curing conditions. Since many of these factors are uncertain and cannot have a specific and accurate formulation for concrete strength, therefore, applying a pre-set mathematical formula roughly predicts the strength of concrete. Inthis research,Genetic algorithm optimization for concrete mix plan is presented. Genetic algorithms are searching algorithms that have been established based on mechanism of natural selection and evolution. These algorithms select the most appropriate strings from organized random data.In every generation, a new group of strings by using the best parts of previous and new accidental sequencewill happen to get a proper answer.First a suitable encoding (or representation) must be found for the problem. The most common representation method of chromosomes in genetic algorithms is in the form of binary strings which is the method used in this study. By iteratingthe computation of marine concrete generation, optimized mix concrete design is achieved.Accordingly, with more detailed information of marine-grade concrete and application of genetic algorithm based on generational leap it can be expected that a new generation of marine concrete will be recoverable
P. Aberoomand Azar; Sh. Moradi; Sh. Piramoon; A. Mashinchian Moradi
Volume 1, Issue 1 , December 2011, , Pages 23-28
Abstract
TiO2 photo catalyst was prepared in presence of nano SiO2 and Hydroxy Propyl Cellulose (HPC) by sol gel method with Titanium Tetra IsoproPoxide (TTIP) as titanium precursor. Additional effect of HPC in preparation of nano catalyst, and photo catalyst properties measured and characterized by FT-IR, FT-Raman ...
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TiO2 photo catalyst was prepared in presence of nano SiO2 and Hydroxy Propyl Cellulose (HPC) by sol gel method with Titanium Tetra IsoproPoxide (TTIP) as titanium precursor. Additional effect of HPC in preparation of nano catalyst, and photo catalyst properties measured and characterized by FT-IR, FT-Raman and SEM. The catalyst size and structural properties of the film were determined by .-Ray Diffraction (.RD). The nano particles of TiO2/SiO2 with HPC contained anatase phase in advance. The surface area measured by the Brunauer, Emmett and Teller (BET) method. Presences of Ti and Si in the nano structure were confirmed by Scanning Electron Microscopy (SEM) equipped with Energy Dispersive .-ray (ED.) spectroscopy. Photo catalyst properties of TiO2/SiO2 examined at first for decomposition of Methyl Red as azo dye, and then for degradation of 5ppm diazinon solution as an organo phosphorous insecticide pollutant in marine source, (Caspian Sea water). Concentration of diazinon during of degradation by TiO2/SiO2 photo catalyst was monitored by UV-Vis spectrophotometery. The insecticide degradation occurred within 105 min of photocatalytic treatment.