مهندسی دریا
Tooba Heidari; nima shahni karamzadeh; Javad Ahadiyan
Abstract
In this study, results of experiments about the trajectory and the advance velocity of inclined and convergent rectangular surface jet into stagnant ambient have been presented. In order to discharge process simulation was used a flume with 3.2 m length, 0.6 m width and 0.9 m height and a rectangular ...
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In this study, results of experiments about the trajectory and the advance velocity of inclined and convergent rectangular surface jet into stagnant ambient have been presented. In order to discharge process simulation was used a flume with 3.2 m length, 0.6 m width and 0.9 m height and a rectangular channel with 6 cm width. Discharge channel was designed in the four angle of convergence 12.5, 25, 45 and 90 degree. This channel injected the jet stream to form of tangent to the surface of ambient and in three different slopes 0, 4 and 8 percent. Receiving fluid had been prepared from urban water. As well as the jet fluid had been prepared from the salt liquidation in water and in three concentrations 5, 15 and 45 gr/l. After running the experiments and using of images routing process were analyzed the data. In this regard, hydraulic and geometric parameters on the trajectory and the advance velocity of jet was investigated. According to the results, increase the slope and decrease the angle of convergence causes increase in length of trajectory and decrease in the advance velocity of jet. Reduce the densimetric froude number causes decrease in length of trajectory. Also, in order to investigate of influence of convergence on the movement path of flow, by comparison of trajectory in convergent channel and simple channel, More relative advance was seen in convergent channel. Finally, using of the data analysis, relation between advance velocity of jet and dependent parameters was determined with RMSE=0.034.
علوم غیرزیستی دریا
Iman Khademi; Mohammad Akbarinasab; Abbas Ali Bidokhti; Mohammad reza Khalilabadi
Abstract
Turbulence is a form of movement characterized by an irregular or agitated motion. Turbulent motions are very common in nature. Most flows in the lower atmosphere and in the upper ocean are turbulent. The Turbulence has long had a special attraction for physicists and mathematicians; it has been called ...
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Turbulence is a form of movement characterized by an irregular or agitated motion. Turbulent motions are very common in nature. Most flows in the lower atmosphere and in the upper ocean are turbulent. The Turbulence has long had a special attraction for physicists and mathematicians; it has been called “the last great unsolved problem of classical physics”.In this study, hydrphysical measured data in the southern part of the Strait of Hormuz and with time step of half an hour during the period December 1996 to March 1998, by the University of Miami, and the meteorological station in island of Gheshm are used , then turbulence was simulated by General Ocean Turbulence Model (GOTM( . The results showed that, turbulent kinetic energy (TKE) in different seasons, with different penetration depths were appeared at during the year. In the cold season, the kinetic energy of the turbulent expands from surface to bottom and in the warm seasons because of existing the seasonal thermocline, depth penetration of TKE are limited, and only expands from surface to top of thermocline layer. In this study, investigation of the turbulent Prandtl number (Pr) shows that, effect turbulent viscosity Preference to the production buoyancy in the middle depth.
علوم غیرزیستی دریا
Parastoo Akbari; Masoud Sadrinasab; Vahid Chegini; Seyed Mostafa Siadat Mousavi
Abstract
Tide is one of the most regular changes of seas and ocean levels which are offering particular importance due to the influence on the flow pattern. According to engineering and environmental needs in industrial economic zone of Persian Gulf, Strait of Hormuz and Gulf of Oman, knowing the tidal characteristics ...
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Tide is one of the most regular changes of seas and ocean levels which are offering particular importance due to the influence on the flow pattern. According to engineering and environmental needs in industrial economic zone of Persian Gulf, Strait of Hormuz and Gulf of Oman, knowing the tidal characteristics of these areas is important. Therefore FVCOM (ocean model) was used to stimulate the tidal amplitude in an area comprising Persian Gulf, Strait of Hormuz, Gulf of Oman and Arabian Sea. Finite volume method is used in this model to discretize the hydrodynamic equations on triangular mesh. Uniform mesh is used with a resolution of 5 km in the model.The constant values of eight diurnal and semidiurnal tidal components are prescribed along the open boundary. In order to validate the model results, after applying harmonic analysis on the model outputs in desired stations, the achieved amplitude of this analysis compared with results which are obtained from the analysis on the available measurement data in these stations. According to the measurement and model results in these stations, meanwhile identifying the four main tidal components, the amplitude pattern of these components was determined in the whole domain. Also, by using amplitude of main components and estimating of F factor, the type of tide was predicted in the study area. Moreover, studying the maximum amounts of tidal velocity in the study area shows that the amount of this velocity in the Gulf of Oman and Arabian Sea is less than 0.1 m/s.
علوم زیستی دریا
Mousa Keshavarz; Ehsan Kamrani; Narges Amrollahi Biuki; Hossein Zamani
Abstract
Some of valuable species of Persian Gulf, such as sea urchins, are accounted less scientific studies due to the lack of any position in the local food baskets. Therefore, this survey is investigated the biometrical parameters of sea urchin Echinometra mathaei for a period of seven months (March– ...
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Some of valuable species of Persian Gulf, such as sea urchins, are accounted less scientific studies due to the lack of any position in the local food baskets. Therefore, this survey is investigated the biometrical parameters of sea urchin Echinometra mathaei for a period of seven months (March– September, 2014) in the intertidal zone of Lengeh Port (26˚32ʹ28 ̋N, 54˚52ʹ29 ̋̋ E). Random samples were collected monthly during spring tides and transferred alive to the laboratory and then the dissection and the separation of different parts of the body were started. Each part of the body length and weight was measured. By a mathematical method the volume of samples was calculated as an elliptical object. This study illustrated the largest and smallest sample were 0.07 and 103.77 grams, respectively. Results showed that the relationships between Total wet weight and Test Diameter (Total Wet Weight = 0.0053 Test Diameter2.3933), Total Wet Weight and Height (Total Wet Weight = 0.0122 Height2.5872) and Total Wet Weight and Volume (Total Wet Weight= 0.0071 Volume0.8706). The correlation coefficient between volume and total wet weight of samples was r=0.94 which shows the accuracy of Disk method. On the other hand, the HDR index was more in compared with the HWR index and it illustrates larger values of Test Diameter in compare with Height. Statical analyses prove that higher values of DWR in compared with HWR are reasonable and accurate in both sexes.
علوم زیستی دریا
mehrshad bahador; Abbas Moradi; Abolfazl Naji
Abstract
Toxicity of trace metals in the environment, bioaccumulation in aquatic environments and in food chains are of great importance.This study concentrates on the distribution patterns of some heavy metals (Pb, Ni, Zn and Fe) in surface sediments of Shoor River estuary. In order to determine the degree of ...
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Toxicity of trace metals in the environment, bioaccumulation in aquatic environments and in food chains are of great importance.This study concentrates on the distribution patterns of some heavy metals (Pb, Ni, Zn and Fe) in surface sediments of Shoor River estuary. In order to determine the degree of Contamination and environmental quality of region sediments, surface sediment (0-5 cm) samples were collected from 4 stations. At each station, three surface sediment samples were collected and the concentration of heavy metals were measured using a flame Atomic Absorption Spectrophotometer; Then indexes such as the Pollution Load Index (PLI) and Potential ecological risk index (RI) for each of the sampling stations and study area applied. The results of PLI represented the low accumulation of studied metals in the surface sediments of the area. Potential ecological risk was also low. The results indicated that Zn and Ni were mainly from anthropogenic discharge, while a significant portion of Pb and Fe were likely from natural inputs.Overall, frequent adverse effects were expected for Ni and occasional adverse biological effects are expected for Zn, whereas for Pb and Fe rare adverse biological effects are expected. Pearson’s correlation indicated that there was positive correlation betweenNi, Pb, Fe, TOM and fine grain size(p
علوم زیستی دریا
shafa hoveizavi; Babak Doustshenas; Gholamreza Eskandari; Ahmad Savari; Hossein Mohammadasgari
Abstract
The main purpose of this study was to describe and estimate the seasonal pattern of discard fish in the waters of the Persian Gulf coasts in Khuzestan. sampling was carried out Monthly by using fishing boats in the waters of Khuzestan province for one year in fishing areas of Lifeh, Boseif, Khure-mussa ...
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The main purpose of this study was to describe and estimate the seasonal pattern of discard fish in the waters of the Persian Gulf coasts in Khuzestan. sampling was carried out Monthly by using fishing boats in the waters of Khuzestan province for one year in fishing areas of Lifeh, Boseif, Khure-mussa and Bahrakan.Discard fish samples were included 61 species from 37 families, nearly 39 percent commercial and 61 percent of non- commercial species. Rayfish and catfish have been observed in most fishing nets. Average size of most species particularly bony fish were under 15 cm. The amount of discard fish per unit of fishing effort is not significantly different between seasons. The highest portion of the catch belongs to Rayfishes. Total discard fishes of gillnets were estimated 3162 tones. Total weight of commercial fishes with small size in trash fish was estimated 225 tones. The rate and proportion of discard fish in total catch of gillnet was estimated 0.23 and 0.31 respectively. Chondrichthyes with 12 species and 60% of gillnet catch has the highest percentage of discard fish of gillnet. A large number of commercial species with small size such as Otolithes ruber (Schneider, 1801), ( Scomberomorus commerson (Lacepede, 1801) and Scomberoides commersonnianus(Lacepede, 1801) could be due to the role of nursery grounds in Khuzestan coastal waters.
علوم زیستی دریا
Hassan Morovvati; M Mesbah; MM Shamsi; A Rezae; Kh Rashidi
Abstract
For this purpose, 144 specimens were studied in five healthy groups. The first group was the control group put in dechlorinated tap water and four respectively in the next group were kept with salinity 4ppt, 8ppt, 12ppt, 16ppt in the same condition . In days (1, 3, 7, 14, 21, 28) samples were collected ...
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For this purpose, 144 specimens were studied in five healthy groups. The first group was the control group put in dechlorinated tap water and four respectively in the next group were kept with salinity 4ppt, 8ppt, 12ppt, 16ppt in the same condition . In days (1, 3, 7, 14, 21, 28) samples were collected from skin of head, ventral and lateral lines. Sections with 0.5- 0.6µm thickness were made and stained with PAS and H&E methods. In histometrical survey, epiderm thickness, numbering of club cells and goblet cells in 200 µm of epiderm length in any area, was investigated comparatively. The results showed that in different salinity concentrations, skin of head, ventral and lateral lines were influenced and changes in epiderm thickness, reduce the number of club cells and increase the number of goblet cells were demonstrated . These changes in different concentrations for each parameter , for significantly increased (p
علوم زیستی دریا
Haleh Ali Abedi; Seied Mohammad Bagher Nabavi; Babak Dustshenas; Ahmad Savari; Mohammad Sharif Ranjbar
Abstract
To investigate some bioecological parameters of dolphins between Qeshm and Hengam Islands waters, the present field study was started on November 2014 and finished on may 2015. During this study morphological features of individuals, within dolphin groups, distribution and reproduction of the Indo-Pacific ...
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To investigate some bioecological parameters of dolphins between Qeshm and Hengam Islands waters, the present field study was started on November 2014 and finished on may 2015. During this study morphological features of individuals, within dolphin groups, distribution and reproduction of the Indo-Pacific Bottlenose dolphin (Tursiops aduncus) and their activities at the sea surface were registered using camera systems. At the same time a field questioner form was design to collect the local fisherman informations regarding to dolphins behaviors in the region. During this study one dolphin species namely Tursiops aduncus (Indo-Pacific Bottlenose Dolphin) was identified. The breeding period of Indo-Pacific Bottlenose dolphin was in spring season and a newborns were observed in April 2015. According to field observations, the mean number of Indo-pacific Bottlenose dolphin groups was 23/13±5/49 with 2 newborns in April 2015.Key words: Indo-pacific bottlenose dolphins, Bioecological parameters, Persian Gulf, Qeshm Island, Hengam Island.
علوم غیرزیستی دریا
Abbas Einali; Vahid Chegini
Abstract
Pozm bay Located in southern coast of Iran near Oman Sea, due to its relative calmness, low depth and being affected by the land substances is interesting to some aquatics species for reproduction and spending part of their growth period. In this research the seasonal variations of physical parameters ...
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Pozm bay Located in southern coast of Iran near Oman Sea, due to its relative calmness, low depth and being affected by the land substances is interesting to some aquatics species for reproduction and spending part of their growth period. In this research the seasonal variations of physical parameters trend of the Pozm pay was investigated during 9 periods since Oct 2011 till Aug 2012. The physical parameters of the sea water were measured by the CTD device in 17 stations from surface to seabed. These parameters are as follows: Temperature, Salinity, Density, Electrical conductivity, Sound velocity, Turbidity, and the Dissolved oxygen. According to the results of this research, the variations of the water temperature are following the air temperature and increase as the air temperature arises in hot seasons. Although due to the low depth of Pozm bay the formation of thermocline layer and water stratification are so low, weak stratification is formed in water column during hot months of the year. The entering flow of Oman Sea water into the Persian gulf, which is less salty comparing to that of Persian gulf, is maximized during late spring and minimized in winter and affects the salinity of Pozm bay water such that its rate is more during mild months than hot months. The variation of the density is influenced by water temperature and the salinity has no effect on them. The summer monsoon has a significant effect on the physical parameters of Pozm bay's water.
مهندسی دریا
Mahboobeh Golaghapoor Kami; Mostafa Jafarzadeh Khatibani; Etemadaldin Rabei Gholami
Abstract
For all new ships sea trials should be carried out as a part of the delivery from the yard to the ship owner. An important part of the delivery sea trial is to determine the speed capability of the ship in the contractual condition, which is traditionally deep, calm water and no wind, at some specified ...
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For all new ships sea trials should be carried out as a part of the delivery from the yard to the ship owner. An important part of the delivery sea trial is to determine the speed capability of the ship in the contractual condition, which is traditionally deep, calm water and no wind, at some specified loading condition. However, it is seldom possible to perform this particular test under such conditions, and when the test is done in other conditions, the result is corrected back to the contractual condition. The correction can be of a significant magnitude. The correction procedure can be influenced by different parameters such as wind resistance, shallow water effect, sea currents and added resistance due to diffraction. There are different experimental methods for correction of measured speed. Since the latter parameter is the most important between others, In this article added resistance due to diffraction has been calculated for three ships using existing methods and comparisoned with the speed correction result of shipbuilder company (Hyundai Heavy Industries). The results show considerable deviation between HHI sea trial speed correction method and other methods. So HHI added resistance calculation method needs to be revised.