M. Heydari; S. Allahyaribeik
Volume 5, Issue 2 , June 2015, , Pages 93-98
Abstract
The process of erosion and desertification affects social communities, agricultural lands and natural resources in coastal areas. The rapid coastline changes would cause social and economic issues in the coastal areas. In this study, Miankaleh coasts and the eastern coastlines of Amirabad port have been ...
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The process of erosion and desertification affects social communities, agricultural lands and natural resources in coastal areas. The rapid coastline changes would cause social and economic issues in the coastal areas. In this study, Miankaleh coasts and the eastern coastlines of Amirabad port have been surveyed due to existing benchmarks since June 2013 until December 2015 in order to analyze the coastline changes in Amirabad port. Then the surveyed lines were compared with sea levels at the time of surveying. The sea level data has been used (to calculate the beach slope) in order to monitor the sedimentation and erosion processes in the coastlines movements. The results of this comparison show that coastline changes are irregular and they may not follow the seal level changes. Therefore the coastline changes in these areas are influenced by erosion and sedimentation units.
L. S. Madani; A. A. Bidokhti; M. Ezam
Volume 2, Issue 1 , March 2012, , Pages 107-114
Abstract
An analytical model for a coastal boundary current was used to investigate heat and salt budget of exchange flows in the Persian Gulf as a marginal sea. Coastal boundary currents exchange heat and freshwater with the mosphere and the offshore waters. As heat and salinity fluxes caused by air-sea interaction ...
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An analytical model for a coastal boundary current was used to investigate heat and salt budget of exchange flows in the Persian Gulf as a marginal sea. Coastal boundary currents exchange heat and freshwater with the mosphere and the offshore waters. As heat and salinity fluxes caused by air-sea interaction and eddy activities, different temperature and salinity associated with boundary currents are adjusted on different length scales. Results obtained from the model show that the temperature and salinity length scales of coastal boundary current are 455 km and 914 km, for summer respectively for summer. In summer the inflow current density initially decreases to a local minimum and then increases, and finally flowing out the basin area with higher density than that of for the inflow. In winter, the estimated temperature and salinity length scales of coastal boundary current are 60 km and 64 km, respectively. In this season, density increases at the beginning with a steep slope and reaches a constant value and, finally the current flows out of the basin area.
Volume 3, Issue 3 , July 2013, , Pages 141-148
Abstract
In this study marine sponges of inter tidal zone from Hengam Island Persian Gulf were collected by wading at low tides in Eskeleh station at locations 55˚ 53ʹ 40ʺ E & 26˚ 40ʹ 53ʺ N.For identifying identification of sponge samples, acid digestion method as a method of early detection and ...
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In this study marine sponges of inter tidal zone from Hengam Island Persian Gulf were collected by wading at low tides in Eskeleh station at locations 55˚ 53ʹ 40ʺ E & 26˚ 40ʹ 53ʺ N.For identifying identification of sponge samples, acid digestion method as a method of early detection and microtome section to identify the skeletal structure were used.All the identified sponges were from class Demospongia, two orders (Hadromerida, Haplosclerida) and four families (Clionidae,Callyspongidae, Chalinidae, Niphatidae) and seven speciesAmphimedonviridis,Haliclonarosea, Haliclonacinerea,Siphonochalina sp., Callyspongiafallax, Callyspongia sp.2,Clionadioryssa. This Research is the exact study to the identification sponges inbasis of microtome sectioning to observe skeletal structures in Iranian Island.
F. S. Sharifi; M. Ezam; A. Karami Khaniki
Volume 2, Issue 2 , June 2012, , Pages 163-170
Abstract
In this study, the capabilities of WAWEWATCH-III and MIKE21-SW for predicting the characteristics ofwind-generated waves in Hormuz Strait are evaluated. The numerical models have been set up using Input data including GFS wind with 5° spatial resolution and 6 hours time intervals, along with ...
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In this study, the capabilities of WAWEWATCH-III and MIKE21-SW for predicting the characteristics ofwind-generated waves in Hormuz Strait are evaluated. The numerical models have been set up using Input data including GFS wind with 5° spatial resolution and 6 hours time intervals, along with the ETOPO1 bathymetry data with 2 arc-minute spatial resolutions. The results of the two model simulations were compared with the available satellite altimetry measurements of significant wave heights at the modeling area. The comparisons show that in deep water WAVEWATCH-III results in more reliable prediction of wave characteristics in comparison to the MIKE-21 SW. While in shallow area the MIKE-21 gives more consistencies with altimetry measurements. These may be due to the benefits of the unstructured grid which are used in MIKE-21, lead to better representations of the coastal area. The investigation on the direction of wind generated waves in the modeling area show that in some regions despite of the increase in wind speed, significant wave height remains nearly unchanged. This is mainly because of rapid changes in wind direction over the Strait of Hormuz.
M. Shapoori; Z. Ghiasvand; Sh. Jamili
Volume 2, Issue 3 , August 2012, , Pages 203-206
Abstract
In this study, we have investigated the effects of mix of Tomato (Solanum lycopersicum) & Carrot) Daucus carota ( and red Bell pepper )Capsicum annuum( as a natural pigment source and astaxanthin as synthetic pigment sources on the skin colour of cichlid fish (Astronotus ocellatus sp., Agassiz, 1831), ...
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In this study, we have investigated the effects of mix of Tomato (Solanum lycopersicum) & Carrot) Daucus carota ( and red Bell pepper )Capsicum annuum( as a natural pigment source and astaxanthin as synthetic pigment sources on the skin colour of cichlid fish (Astronotus ocellatus sp., Agassiz, 1831), which are generally white with red patches in the dorsal skin. The fish were fed diets containing 100 mg kg–1 astaxanthin and natural pigment. The amount of both natural and synthetic pigment sources given as feed was 100 mg kg–1, and the experiment was continued for 60 days. Total carotenoid content of the fish was determined spectrophotometrically at the end of the experiment. As a result, while a visible change of colour in the skin of the fish fed on the feed containing astaxanthin was observed with 0.43 ± 0.2 mg g– of pigment accumulation, a relatively change of colour was observed in the skin of other fish that were fed on the feed containing powder of Tomato & Carrot and red Bell pepper with 0.35 ± 0.2 mg g– of pigment accumulations, respectively. Therefore, it was determined that these pigment sources have an effect on the colour of cichlid fish.
L. VahdatiRaad; H. Khara
Volume 2, Issue 4 , December 2012, , Pages 249-254
Abstract
Wetlands are often considered sinks for contaminants, and Aquatic plants have been shown to play important roles in wetland biogeochemistry through their active and passive circulation of elements. In this research, in order to evaluate the concentration level of heavy metals released by the urban, industrial ...
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Wetlands are often considered sinks for contaminants, and Aquatic plants have been shown to play important roles in wetland biogeochemistry through their active and passive circulation of elements. In this research, in order to evaluate the concentration level of heavy metals released by the urban, industrial and agricultural activities at the margin of the rivers flowing into Anzali lagoon, as well as finding lead and cadmium accumulated in two plant species quoted below, a sampling has been made on two kinds of aquatic plants in the lagoon at three randomized stations based on the density of the plant coverage. In this project two regional aquatic plant species asHyrocotyleranocloides, Ceratophyllumdemersumhave been investigated for absorption of lead and cadmium. Results show an average concentration of lead in Ceratophyllum being 53.11 ppm, for Hydrocotyle 77.8 ppm, and of cadmium in Ceratophyllum being 4.46 ppm and for Hydrocotyle 6.28 ppm. According to results, lead has been the most abundant between these two metals inside plant organs regardless the specie. The statistic test gives the results under the confidence level 95% proving the amount of the absorption being significant in the stem of Hydrocotyle plant rather than in the root or the leaf compared with other species.
M. Tajari; F. Azarsina; N. Ashrafi Khorasani
Volume 3, Issue 1 , March 2013, , Pages 33-42
Abstract
Explosion and fire on an offshore rig can lead to its minor or complete damage and sinking which means the loss of life or environmental pollution. Hence the use of techniques such as blast wall is crucial to reduce the detrimental effects. These blast walls are designed for explosion wave of length ...
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Explosion and fire on an offshore rig can lead to its minor or complete damage and sinking which means the loss of life or environmental pollution. Hence the use of techniques such as blast wall is crucial to reduce the detrimental effects. These blast walls are designed for explosion wave of length between 0.1 to 1 of load mainly to protect the personnel and critical sections. In this research, the behavior of an offshore platform jacket under blast wave 0.2 and 0.7of load is studied with the blast wall thickness of 1, 5 and 10 mm. The analysis is performed in both plastic and elastic aspects in which we need to consider the nonlinear geometrical and material properties.
madjid ghodsi hassanabad; ajang fardad
Volume 4, Issue 1 , February 2014, , Pages 37-46
Abstract
The complete 3D nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. For describing the dynamics of the system, the Newtonian derivation procedure is followed. The velocity field inside the pipe formulated using hydrostatic and Bernoulli equations. The hydrodynamic ...
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The complete 3D nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. For describing the dynamics of the system, the Newtonian derivation procedure is followed. The velocity field inside the pipe formulated using hydrostatic and Bernoulli equations. The hydrodynamic effects of external fluids are taken into consideration through the nonlinear drag forces in various time steps and the added inertia due to the hydrodynamic mass. Following the Newtonian derivation, the dynamics of the pipes element with effects of internal fluid are considered separately and the final governing set is derived by combining the equations of inertia equilibrium. The study focuses specifically on the effect of the inner flow to the global dynamics of the riser. This task is accomplished using time domain teachings and the Finite Element method is used as a powerful numerical method. Moreover the Euler-Bernoulli beam theory is used response to model the dynamic behavior of the flexible risers.
F. Orak; M. Bakhtiari; H. Bahrami
Volume 5, Issue 1 , January 2015, , Pages 41-47
Abstract
Seawalls are built for Protecting of beaches against waves and preventing the progression of water to the beach. For a proper understanding about these constructions, a suiTable information about applied loads on these constructions should be existed. One of the important load that applied on these constructions ...
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Seawalls are built for Protecting of beaches against waves and preventing the progression of water to the beach. For a proper understanding about these constructions, a suiTable information about applied loads on these constructions should be existed. One of the important load that applied on these constructions is sea wave. Others loads are included: weight force of the walls, weight force of the soil behind wall, weight force of the sea water on wall base and the forces applied on beach. Seawalls are built in different geometric shapes like vertical, Inclined and curvature walls (with variable slope). In this study, 4 geometric shape: vertical, Inclined, Convex and concave are simulated for analyzing the effect of geometry on stability of seawalls. So FLAC 3D software are used. The results show that the minimum earth subsidence and horizontal displacement are obtained for convex wall and the maximum amount of these parameters for vertical wall.
A. Mashinchian Moradi; M. Jalali Mosallam; M. R. Fatemi
Volume 1, Issue 1 , December 2011, , Pages 51-58
Abstract
In this study, the amount of nickel and vanadium elements in the soft tissues of rock oysters (Saccostrea
cuculata) and sea water from coastal areas of Qeshm Island, the biggest island of Persian Gulf located in the south of Iran, were measured to evaluate the contamination of the aquatic environment ...
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In this study, the amount of nickel and vanadium elements in the soft tissues of rock oysters (Saccostrea
cuculata) and sea water from coastal areas of Qeshm Island, the biggest island of Persian Gulf located in the south of Iran, were measured to evaluate the contamination of the aquatic environment and organisms. Following the bioassay, weighing and chemical digestion of the samples, finally the amount of nickel and vanadium in the soft tissues of the oysters and sea water samples were measured via the ICP system. The results indicated that the average concentration of nickel and vanadium found in the sea water were respectively: 15.7 and 37.9 micro grams per liter and in the soft tissues of oyster: 2.44 and 1.91 mg per kg respectively. In comparison with the FDA and WHO standards, only the concentration of nickel in the soft tissues of oysters was in a permitted level, and the rest exceeded the permitted levels. The average concentration of metals in the north side of the island were more than that found in south of the island but
this difference was not statistically significant (p> 0.05).
H. Chitsaz Boroujerdi; A. A.Bidokhti; Sh. Sharafatmandjoor
Volume 3, Issue 2 , June 2013, , Pages 85-90
Abstract
In order to present a quantitative indicator for the onset of instability, in this paper, the critical points of a stratified gravitational flow on a slope are found and analyzed. These points are obtained by means of the solution of the two-dimensional Navier-Stokes equations via the standard Arakawa-C ...
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In order to present a quantitative indicator for the onset of instability, in this paper, the critical points of a stratified gravitational flow on a slope are found and analyzed. These points are obtained by means of the solution of the two-dimensional Navier-Stokes equations via the standard Arakawa-C finite-difference method. Results show that in the marginal Richardson numbers, the critical points begin to originate. Also, the cyclic evolution in the temporal differenced density field in the vicinity of the critical points is used as a quantitative criterion of the onset of mixing. Therefore, it is possible to predict the beginning of the mixing phenomenon via analysis of only a limited number of critical points.
S.M. Sajadi; F. Azarsina
Volume 5, Issue 2 , June 2015, , Pages 99-113
Abstract
Given the worldwide industry progress in the construction of massive concrete structures, it would be a good idea to use concrete gravity base structures (GBS).In this regard, better understanding of thesestructuresregardingtheiradvantages and disadvantages in offshore areas seems necessary.The present ...
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Given the worldwide industry progress in the construction of massive concrete structures, it would be a good idea to use concrete gravity base structures (GBS).In this regard, better understanding of thesestructuresregardingtheiradvantages and disadvantages in offshore areas seems necessary.The present study employed MacCammy-Fuchs method, which is based on the size of the structure to the wavelength and the range of Keulegan-Carpenter number; in this method, diffraction theory and Bessel functions are used to compute the velocity potential function and consequently compute the hydrodynamic pressure on the components of the structure.The results of this study with regard to the harmonic dynamic response of the rocking motion of the platform under wave loads revealed that (i) the computed torque value converges to a definite value by decreasing the size of elements,and (ii) Bessel functions can be represented by amplitude and phase functions which have identical performance.The time-history response of the gravitybase structure, and the amplitudechanges of rocking motion relative to frequency and the height of the waves are other results obtained in this study. Finally, the stability index of the GBS shows that the platform is within safe limits.
N. . Allahyaribeik; S. Allahyaribeik
Volume 4, Issue 2 , June 2014, , Pages 101-106
Abstract
In recent years, the application of Activity-Based Costing in Port industry has been deeply researched in theory and practice, but researchers only concentrate on the bulk and general cargo’s ABC in loading and unloading operations and there is little about the liquids and chemicals’. Based ...
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In recent years, the application of Activity-Based Costing in Port industry has been deeply researched in theory and practice, but researchers only concentrate on the bulk and general cargo’s ABC in loading and unloading operations and there is little about the liquids and chemicals’. Based on the liquids and chemicals’ handling process and the particularity of their cost accounting, the paper establishes quality and safety activity center, steam heating, electric trace heating activity center, temperature maintenance activity center and so on .At the same time, the paper focuses on their cost drivers and their measuring method in order to improve the accuracy of costing in loading and unloading operations.
S. M. R. Fatemi; Gh. Vossughi; P. Ghavam Mostafavi; F. Bahri
Volume 2, Issue 1 , March 2012, , Pages 115-120
Abstract
Rocky shores are one of the most important habitats of marine environment in coastal areas. This study was done in 2010-2011 to investigate the diversity of true crabs in intertidal rocky shores of Qeshm island. Samples were collected from intertidal zones during the low-tide at 5 stations. The specimens ...
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Rocky shores are one of the most important habitats of marine environment in coastal areas. This study was done in 2010-2011 to investigate the diversity of true crabs in intertidal rocky shores of Qeshm island. Samples were collected from intertidal zones during the low-tide at 5 stations. The specimens were fixed in 70% Etanol and transferred to laboratory for identification. Altogether, 15 crab species belonging to 8 families and 14 genus were identified. 4 species were from Portunidae, 3 species from Eriphiidae, 2 species from Majidae,2 species from Grapsidae were identified. The others families including Euryplacidae, Leucociidae, Pilumnidae and Xanthidae families have the lowest species richness with only 1 species per family. Portunidae family with 4 species in intertidal zone had the highest species richness amongst studied stations. 3 species of Eriphia smithi from Eriphiidae family, Leptodius exaratus from Xanthidae family and Thalamita crenata from Portunidae family were present at all three intertidal zones (High tide, Mid tide and Low tide).
Volume 3, Issue 3 , July 2013, , Pages 149-152
Abstract
The effects of five different foods including: blood worm, artemia cyst, Artemia mass powder, gammarus mass powder and ordinary commercial food were studied on Siamese fighting fish (Bettasplendens) propagation efficiency during thirty days in a Randomize Totally Design with 4 repeats .Experimental plots ...
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The effects of five different foods including: blood worm, artemia cyst, Artemia mass powder, gammarus mass powder and ordinary commercial food were studied on Siamese fighting fish (Bettasplendens) propagation efficiency during thirty days in a Randomize Totally Design with 4 repeats .Experimental plots had been consisted of twenty 30*30*40 (cm) aquarium which a pair of male and female brood stocks was introduced to each one. Male and female were separated in each plot by a glass plate for 15 days in order to prepare for spawning. The results of the experiment showed no significant differences on spawned ova, ova diameter, and hatched ova among various ration treatments (p>0.05), but the averages comparison of referring factors showed that spawned ova, hatched ova, and ova diameter, were better in those brood stocks that had been fed by blood worm food treatment. However, ordinary commercial food treatment resulted weakest averages through all ration treatments.
A. Mashinchian Moradi; A. H. Dashti; M. R. Fatemi; P. Aberoumand Azar
Volume 2, Issue 2 , June 2012, , Pages 171-176
Abstract
Tracking and determining the amount and types of urban sewage that is being releasing to the environment is important in planning for wastewater treatment systems and water quality control. In this research, in four stations of Anzali Lagoon, (by means of a gas chromatograph device with mass ...
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Tracking and determining the amount and types of urban sewage that is being releasing to the environment is important in planning for wastewater treatment systems and water quality control. In this research, in four stations of Anzali Lagoon, (by means of a gas chromatograph device with mass detector spectrometer) wastewater pollution has been measured and evaluated with molecular indicator Linear Alkyl Benzene(LABs) in bivalve “Anodonta cygnea”. Average concentrations of LABs were calculated 520 μg/kg dry weight in samples of station 1, 1245 in station 2, 2144 in station 3, and 1746 in station 4. Results from this study indicate severe LABs pollution in studied stations in Anzali Lagoon’s sugesing that urban wastewater has reached these stations.
H. Zare Banadkooki; S. Mazaheri; M. R. Akbarpour jannat; A. Aziminejad
Volume 2, Issue 3 , August 2012, , Pages 207-214
Abstract
It is proposed to use a single base platform in the Persian Gulf considering its low depth and more appropriate environmental conditions in comparison to North Sea and Mexico Gulf where this kind of platform is very popular. The pile of platform is responsible for transmission of environmental loads ...
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It is proposed to use a single base platform in the Persian Gulf considering its low depth and more appropriate environmental conditions in comparison to North Sea and Mexico Gulf where this kind of platform is very popular. The pile of platform is responsible for transmission of environmental loads resulted from waves, currents, wind and dead loads to foundation of platform. Using SACS 5.3 software, we woke modeling of waves, currents and wind forces, stood the load combination resulted from these forces on the concrete pile and read for anchors analyzed by the software. Considering wave load is more important than wind and current loads, it is a prevailing load in load combination design. After changing the wave load design, we saw changes in anchor and force of pile. We used a concrete square basis of 1 depth in order to design foundation. After modeling the above mentioned basis by PLAXIS.3D FUNDATION software, forces and anchors resulted from load combination of currents, waves and wind. Layering and seabed soil type in the Persian Gulf is one of the most important parts in foundation design. Soil laboratory determined the kind of sea bed soil. These tests were done both as field tests and as laboratory tests carried on samples collected from the site. After modeling foundation and analyzing it, we read the stress under the foundation and pore water pressure and then compared it with environmental loads.
A. Mashian Moradi; R. Golshani
Volume 2, Issue 4 , December 2012, , Pages 255-258
Abstract
Pesticides are used extensively in agricultural lands in Northern provinces of Iran which makes river ecosystems more vulnerable to pesticides pollution. This study was conducted in three river estuaries (Babolrud, Tajanrud and Gorganrud), focusing mainly on the concentration levels of organophosphate ...
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Pesticides are used extensively in agricultural lands in Northern provinces of Iran which makes river ecosystems more vulnerable to pesticides pollution. This study was conducted in three river estuaries (Babolrud, Tajanrud and Gorganrud), focusing mainly on the concentration levels of organophosphate pesticides (diazinon, malathion, azinphos-methyl) in the muscle tissue of golden mullet fish, an economically important and highly consumed fish in the region. The research was conducted in 2011-12. During the study, 27 samples of mullet fish were collected. After extraction and purification process, the average level of concentrations of diazinon, malathion in mullet fish muscle tissue were measured using Gas Chromatography. Based on the results, the highest average concentrations of azinphos-methyl belonged to samples taken from Babolrud river estuary (1.28 mg/kg), while these concentrations for Tajan and Gorganrud samples were respectively 0.76 and 0.04 mg/kg. The highest concentration of malathion in mullet fish muscle was found in the samples taken from Tajan River (0.19 mg/kg). The concentration of malathion in samples taken from Babolrud and Gorganrud rivers were also 0.17 and 0.07 mg/kg, respectively. The highest concentration of diazinon in mullet fish muscle was found in samples taken from Babolroud River (0.27 mg/kg), and then in samples from Tajan and Gorganroud rivers (respectively 0.09 and 0.08 mg/kg). It was concluded that the most contaminated river estuary was Babolrud river estuary.
Volume 3, Issue 1 , March 2013, , Pages 17-24
Abstract
This paper presents simplified hydrodynamics model for a biomimetic robot fish based on quantitative morphological and kinematic parameters of crangiform fish. The motion of four Pangasius sanitwongsei with different length and swimming speed were recorded by the digital particle image velocimetry (DPIV) ...
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This paper presents simplified hydrodynamics model for a biomimetic robot fish based on quantitative morphological and kinematic parameters of crangiform fish. The motion of four Pangasius sanitwongsei with different length and swimming speed were recorded by the digital particle image velocimetry (DPIV) and image processing methods and optimal coefficients of the motion equations and appropriate location of joints are empirically derived. The swimming speed of fish can be adjusted by changing oscillating frequency, amplitude and the length of oscillatory part, respectively. Experimental results show that the oscillating amplitude increases dramatically from 1/3 of body and is very small near the head. So the second order function which describes wave amplitude of Pangasius sanitwongsei undulatory movement equation was found and the oscillatory motion of the biomimetic robot fish will be simulated according to this equation.
a bazzi
Volume 4, Issue 1 , February 2014, , Pages 47-56
Abstract
Levels of the heavy metals Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni), Iron (Fe) and Manganese (Mn) were determined by graphite furnace atomic absorption spectrophotometer (Model 67OG) in coastal water, sediments and soft tissues of the Saccostrea cucullata, from the ...
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Levels of the heavy metals Copper (Cu), Zinc (Zn), Lead (Pb), Cadmium (Cd), Chromium (Cr), Nickel (Ni), Iron (Fe) and Manganese (Mn) were determined by graphite furnace atomic absorption spectrophotometer (Model 67OG) in coastal water, sediments and soft tissues of the Saccostrea cucullata, from the intertidal zone at five stations in the Gulf of Chabahar on the Iranian coasts along the Oman Sea.The concentrations of heavy metals in water ranged between 3.37–5.74, 18.01–22.62, 4.24–4.52, 0.15–0.19, 20.16–21.46, 16.42–17.14, 15.43–24.76 μg L-1and 7.06–8.67 μg L-1 for Cu, Zn, Pb, Cd, Cr, Ni, Mn and Fe, respectively. The corresponding concentration values in the sediments were 46.79–54.76, 40.14–43.12, 25.63–28.23, 0.53–0.63, 47.16–51.43, 26.45–28.68, 52.13–53.46 and 84.42–89.14 μg g-1for Cu, Zn, Pb, Cd, Cr, Ni, Fe and Mn, respectively. The highest accumulated metals were Zn, Cu and Mn in S. cucullata while the lowest one was Cd. The highest concentrations of all metals in water, sediments and Oyster were recorded at Tiss harbour eastern parts of the Gulf, while the lowest concentrations were recorded at Damagheh. Based on this research, land based activities; shipping activity and the sewage disposal from vesseles and residential area close to these harbors are the main source of metal pollution in the Gulf of Chabahar.
M. Atashrazm Jirande; F. Azarsina; M.S. Seif
Volume 5, Issue 1 , January 2015, , Pages 49-54
Abstract
During design spiral of a merchant ship or a naval vessel, it is important to perform towing tank tests in order to measure its performance either in calm water maneuvers or in waves for seakeeping performance. Also, to optimize a hydrodynamic design, towing tank tests are advantageous.This article presents ...
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During design spiral of a merchant ship or a naval vessel, it is important to perform towing tank tests in order to measure its performance either in calm water maneuvers or in waves for seakeeping performance. Also, to optimize a hydrodynamic design, towing tank tests are advantageous.This article presents the results of an applied research project. The objective of this project is to design and manufacture a six-componentbalance dynamometer to measure drag force, lateral force, yaw moment, roll moment, andheave and pitch motions. Various stages of this work are presented in the text. The main steps of this activity are to design, prototype,and install strain gauges, and eventuallycalibratethem. Using this procedure, implementing the relevant criteria, the appropriate measures of the strain were selectedmore on the basis of recommendations of professional bodies.Material selection of suitable metal machining and construction work is done. Next, the strain meters were installed onthe balance. After equipment calibration, dynamometer is ready for the ultimate test in towing tank
F. Azarsina
Volume 1, Issue 1 , December 2011, , Pages 59-68
Abstract
In this paper, a feasibility study of building a Human Powered Hydrofoil (HPH) vessel is reported. Hydrofoil vessels are a well-known class of high-speed crafts. In addition to high-speed operation, the hydrofoils have a reliable maneuvering capability, good stability and proper operation in waves. Also, ...
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In this paper, a feasibility study of building a Human Powered Hydrofoil (HPH) vessel is reported. Hydrofoil vessels are a well-known class of high-speed crafts. In addition to high-speed operation, the hydrofoils have a reliable maneuvering capability, good stability and proper operation in waves. Also, a human powered vehicle, nowadays is an advancing idea. Different aspects of the design and construction of a HPH is explained. Some ideas are principles and others are ideas, set forth and should be further analyzed and validated theoretically and experimentally.
M. R. Tabeshpour; B. Ataie Ashtiani; M. S. Seif; A. A. Golafshani
Volume 3, Issue 2 , June 2013, , Pages 91-98
Abstract
Because of fluctuation in leg tension, pitch motion is very effective fatigue and life safety of leg elements in tension leg structures (TLSs). In this paper an exact solution for pitch vibration of a TLS interacting with ocean wave is presented. The legs of TLP are considered as elastic springs. The ...
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Because of fluctuation in leg tension, pitch motion is very effective fatigue and life safety of leg elements in tension leg structures (TLSs). In this paper an exact solution for pitch vibration of a TLS interacting with ocean wave is presented. The legs of TLP are considered as elastic springs. The flow is assumed to be irrotational and single-valued velocity potentials are defined. The effects of radiation and scattering are considered in the boundary value problem. Because of linear behavior of legs during wave excitation, ignoring coupling effects with other degrees of freedom, the analytical solution of pitch response has good agreement with the real behavior of the structure.
M. Alipour; M. Fallahi; T. Valinassab
Volume 4, Issue 2 , June 2014, , Pages 107-111
Abstract
In this study, effects of pH and salinity on growth and bloom of Dunaliella sp. algae were investigated. The algae were reared in different pH (6.0, 6.8, 7.0, 7.3, 7.6, 8.0, 8.6, 9.0, 9.7 and 11.0) and salinities (20.0, 31.6, 50.1, 79.4, 117.1, 125.9 and 200.0 ppt) at Inland Aquaculture Research Institute ...
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In this study, effects of pH and salinity on growth and bloom of Dunaliella sp. algae were investigated. The algae were reared in different pH (6.0, 6.8, 7.0, 7.3, 7.6, 8.0, 8.6, 9.0, 9.7 and 11.0) and salinities (20.0, 31.6, 50.1, 79.4, 117.1, 125.9 and 200.0 ppt) at Inland Aquaculture Research Institute Phycolab during 2011. After 96 h, the algae reared in 50ppt salinity and below that had negative growth, however, beyond the 50 ppt, it started to grow and reached the growth peak in 117.1 ppt. In 125 and 200 ppt, the algae growth decreased compared to 117.1 ppt. Exceptsalinityof31.62and50.11descendant of the other groups was significant (P < 0.05). At the different pH, after 96 h the lowest growth was observed in pH 11, whereas, the highest growth was in pH 7.6 while increasing pH above 9.0 led to negative growth. These differences were significant (P <0.05).
A. Mohseni Arasteh; K. Lari; S. S. Shariati
Volume 2, Issue 1 , March 2012, , Pages 121-128
Abstract
The weather forecast by satellite data is a good guideline for assessment of voyage planning route in order to have safe and economic voyage for shipping. ISO15016, "Guidelines for the assessment of speed and performance by analysis of speed trial data", has been developed by the working group ISO/TC ...
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The weather forecast by satellite data is a good guideline for assessment of voyage planning route in order to have safe and economic voyage for shipping. ISO15016, "Guidelines for the assessment of speed and performance by analysis of speed trial data", has been developed by the working group ISO/TC 8/SC 9/WG 2. This paper presents the effects of wave speed & direction, wind speed and direction, current speed and direction, and depth of water in vessel voyage planning which is based on meteorology and satellite data and computer program based in the ISO/DIS 15016. The interpolation between satellite data, historical chart data and observed data can optimize voyage route and cause reduction in sea passage time and fuel oil consumption. Various analysis methods for resistance increase due to ship motion, wave diffraction, wind, steering, drifting, water temperature, salt content, deviation of displacement, hull and propeller surface roughness and shallow water effects are considered in this paper and could be contained in computer program.