مجله علوم و فنون دریایی
سال هفدهم شماره 3 (پاییز 1397)

The actue toxicity test was performed instatic renewal system based on the standared method Proposed by OECD during 96 h, in which physicochemical parameters of test water including pH, dissolved oxygen and Temprature were daily monitored. to determine the lethal range of diazinon of fish a range finding test was carried out in aquariums coutaing 10 L of test solution. The acute toxicity test was then preformed in 5 treatment in triplicats. The obtained data were analyzed using probit analysis with %5 confidence limit. acording to the results, 24 h LC50, 48 h LC50, 72 h LC50 and 96 h LC50 of diazinon on common seabream was 10/974, 10/391, 9/134 and 7/316 respectively. The Maxium Acceptable Toxicant Concentration (MATC) of diazinon on common seabream was 0/073 mg/l and the Lowest observed effect concentration wich is equal to 96 h LC50 was 2.63 mg/l. The results indicated that compared to other fishes is more resistant against diazinon . in addition diazinon lethal toxicity takes place in a waide range of toxicant concentration.

Sillaginidae family fish from Perciforms, are appropriate candidates for shallow water and coastal aquaculture. At least three species of this family represents in the Persian Gulf. Genetic analysis of Sand whiting Sillago sihama , the most common species of family performed using COI gene. During the present study 10 samples were collected from Bushehr and Hormozgan provinces coastal waters. DNA extracted by modified CTAB method. Polymerase chain reactions were performed using universal primers - FISHF1 and FISHR1-. Sequencing results showed a 627 bp amplified fragment. Performing BLAST supported high identity to Sillago sihama species, hence morphometric identification confirms molecular barcoding. Genetic distance of 0.02 was calculated between samples of two areas based on Kimura 2- parameter using Mega software. Constructed phylogenetic tree using neighbor joining method whereas the Acanthopagrus latus sequences was used as an outgroup revealed no differentiation between two stations samples. In conclusion based on the results of the present study, the gene flow was high among studied samples and no significant differentiation was observed between Bushehr and Hormozgan samples. In conclusion no discrete populations differentiated based on the results of the present study.

To evaluate the infection of carp bream ,Abramis brama, with ligula intestinalis in Golestan province, 92 fish samples from two regions: Gorganroud (61 samples) and Alagol lake (31 samples) were investigated. According to the result in the present study, the prevalence of ligula intestinalis plerocercoid infestation in carp bream from Alagol Lake for male, female and overall (male and female) were 5.88%, 7.14% and 6.45%, respectively, also in the Gorganroud river for male, female and overall (male and female) were recorded as 22.22%, 26.47% and 24.59%, respectively. Based on the statistical analysis, the prevalence of this parasite in fish specimens from the Gorganroud was recorded significantly higher than Alagol lake`s specimens. In this study the mean intensity ± SD of parasite infestation for carp beam in Alagol Lakes and Gorganroud were recorded as 2.5 ± 2.1 and 2.00 ± 1.25, respectively. There was no significant difference in mean intensity of ligula intestinalis infectation between two mentioned regions (P

For this study different time series of MODIS level-3 thermal IR SST data from 2013-2014 has been processed and thermal fronts the of Persian Gulf and the Oman Sea (47.6°E to 67.7°E and 18°N to 31°N) region mapped using the method, the Canny algorithm and Gaussian filter. Monthly thermal front images of this region are mapped during the period of January 2013 to June 2014 are classified into Summer Monsoon (June, July, August, September), Winter Monsoon (October, November, December, January) and Pre Monsoon (February, March, April, May) periods and their characteristics are discussed here. The results show that high frequency of SST fronts were observed in the Oman Sea and Persian Gulf in October, November, December, January and May in 2013 year and January, November and December in 2014 year. The number of fronts increases since the beginning of winter to early spring and the beginning of fall, too. The remaining these fronts move with current toward the Arabian Sea and Indian Ocean at the beginning of the summer monsoon. Sustainable and cohesive front was seen near the Arvand River in the Persian Gulf that is presents in the cold months more. This front will disappear in the months of July, August and April 2013 and 2014. The other stable front is in the Oman Sea in southern Afghanistan. Most of the front are presenting in the warmer months of June, September, October in 2013 and in June, August and October in 2014.

High speed craft with the wide and various uses of entertainment, sporting, commercial and military, usually has a top speed of 30 knots. Due to the limitations of the design, use of propulsion system is a key issue, with regard to the desirable features surface-piercing propeller, their use in the propulsion system of the vessel, has been very useful. High efficiency, no restrictions to increase the diameter, resistance equipment supplied propeller removed, the proper functioning of cavitation, are examples of these features. To achieve the best efficiency and thrust requirements, requires accurate determination of the coefficient of hydrodynamic thrust and torque. Given the importance of determining the coefficients and their dependence on various physical parameters and geometric, it is necessary to understand the effect of these parameters on the hydrodynamic coefficients, so in this study, experimental tests and collect data using sensitivity analysis, the weight of each parameter and the interaction of parameters surface-piercing propeller to evaluate the hydrodynamic coefficients on the propeller thrust, propeller torque, and therefore performance, is desired. Based on the results obtained, the parameters of step angle, skew and compared to other parameters, have the greatest impact in changing the propeller efficiency, while changing the ratio Immersion, the change will have little impact on efficiency and propeller.

Nanoparticle biosynthesis is considered an important part of nanotechnology which is economically viable; it is an environmentally-friendly procedure with great advantages compared to physical and chemical ones. In the present study, a green approach is presented for the first time for producing alpha aluminum oxide nanoparticles using Sargassum ilicifolium algae in which its methanolic algae extract was employed as a reducing agent and stabilizer layer. Under optimal conditions of 25ºC and pH=4, 10% of algae extract concentration and 0.05M Al2(SO4)3 salt, aluminum cations were reduced completely to nanoscale phase within 24 hours. Nanoparticle formation was confirmed through UV-Vis technique at wavelength of 225nm. XRD technique confirms the formation of alpha aluminum oxide size 35 nanometers in a hexagon shape. The results of TEM confirms the spherical almost shape of the produced nanoparticle, the results of SEM shows the average size 33.40 of the nanoparticle, and the results of EDX indicated the purity of the produced nanoparticle which is formed of only oxygen and aluminum atoms.