مجله علوم و فنون دریایی
سال نوزدهم شماره 3 (پاییز 1399)

In this study, the effects of different dietary protein and salinity levels on cellular parameters of hemolymph in white leg shrimp (as a part of immune system) of the white leg shrimp (Litopenaeus vannamei) juvenile were studied. The number of 350 shrimps with the average weight of 5.55±0.18 g and length of 8.81±0.15 cm were distributed randomly in 27 ten tones (length: 600 cm, width: 170 cm and height: 100 cm) concrete tanks. A 3×3 factorial experimental including three levels of salinity (0-3, 12-15 and 32-35 ppt) and three dietary protein levels (25, 35 and 45%). Experimental shrimps were fed to satiation 4 times a day throughout the experimental 56 days. According to the results cellular parameters like: total hemocytes count (THC) and differential hemocyte count (DHC) were analysed and recorded. The dietary protein levels 35% and salinity of 32-35 ppt had direct positive impact on THC and granular cells (GC). Although the semi granular poisonous cells have been decreased with the increase in both of the experimental variables (P≤ 0/05) and no effected on the agranular cells. So based on the results of this study, the protein diet with the 35% is suggested for L. vannamei. Taking in to consideration the results of the study we can say the best water salinity for culture of this species is 32-35 ppt.

Apelin and Resistin are two novel adipokine that are closely related with insulin resistance and type 2 diabetes .The purpose of this endeavor was to investigate the effect of an 8-week selected aquatic aerobic training period on plasma concentrations Apelin and Resistin in middle-aged men with type 2 diabetes.20 types 2 diabetic men selected as subjects and were randomly divided into experimental (n=10) and control groups (n=10). Both groups were similar regarding their age and body mass indexes. The training program for the experimental group included three weekly sessions of aquatic aerobic exercise for a period of eight weeks with an intensity of 55-70% of maximal heart rate. The control group had no participation in any regular training program. The blood samples were analyzed for apelin and resistin. Independent and dependent t-tests were implemented to compare parameter averages at α=0.05.The results showed that in the experimental group, apelin (P=0.001) and resistin(P=0.034) levels decreased significantly. The comparison of the differences between the two groups showed that the changes in apelin (P=0.343) and resistin (P=0.412) levels was not significant. The results of this study showed that aquatic aerobic training can be effective by reducing the levels of applein and resistin in controlling blood glucose and treating men with type 2 diabetes.

Monitoring of benthic communities is important factor in ecosystem health studies. The Caspian Sea is considered as an independent zoogeographical region due to its diversity, specificity and endemism of its fauna. For studying frequency and distribution patterns of macrobenthic community, 5 transects along the Southern Coasts of Caspian Sea from Astara to Chaboksar were sampled. In each transect 3 stations with the depth of 1,5 and 10 meters were selected in perpendicular line to the beach .Physical parameters such as Temperature, Salinity, Dissolved Oxygen and pH were measured in addition to sediment grain size. Sampling has done twice a year (winter 2014 and summer 2015).Totally 38 macro benthos species were identified. Gastropods of Hydrobiidae family and polychaet Streblospio gynobranchiata were the dominant group with the contribution of 80% of total macrobenthos population. Average number of total benthos was 2250 individual/m2 in winter and 2630 individual/m2 in summer. Non-parametric statistical tests showed significant difference between number and frequency of species in different depths (p<0.05). Similarity coefficients and hierarchical analysis determined depth and salinity as the most effective factors. Canonical correspondence analysis confirmed this result and mentioned the grain size of substrate as an important one. Difference in slope of shoreline was another determining factor. Final results showed that sandy bottoms with lower number of macro fauna like amphipods and more dissolved oxygen are frequent in shallow waters and deeper muddy bottoms have characteristics of lower oxygen and more salinity with polychaeta and Gastropods in high numbers.

The ultimate goal of the electrical industry is to supply reliable energy. Therefore, accurate and on time detection of faults have always been the main concern of electricical utility users. In recent years, the use of cables has grown steadily and has made it difficult to detect faults and locations. If the cable network is intended for a particular application, such as a generator connection cable to industrial power grid, its importance will be increased, and the Lack of timely performance of the protection system will cause irreparable damage. In this paper, a novel method is proposed for detecting and determining the location of faults in cable using a combined wavelet transform algorithm and an optimized MLP network with a bee algorithm. In the proposed algorithm, two initialization modules and prediction analyzes are proposed to increase the selection capability. The algorithm is done by the DigSILENT and MATLAB software and implemented on the ship industrial cable network. The simulation results indicate an accuracy of 93% for the considered algorithm in determining the correct location of the fault.

In this study ahead to solve the equations of the boundary layer on a plate Mthrkprdakhth is steady. It takes into account the energy equation, heat transfer components also be considered. The solution method used to solve nonlinear equations, the method is Lie group. The initial conditions using an iterative algorithm for solving differential equations with relatively good accuracy estimates. Then, the fourth-order Runge-Kutta method to solve environmental values ​​across functions to be obtained. Using the results of the numerical solution of the boundary layer heating speed and simulate the effects of radiation coefficient, the speed and suction factor to be considered in the boundary layer. Finally, to assess the results of the numerical solution methods Lie group, the results of earlier shooting method is used. A comparison of numerical solution methods and techniques shooting show Lie group Lie group method convergence addition to high speed, good accuracy as well.

Unwanted fishes in Caspian Sea cray fish pond culture considered as food competitor in which decreased pond yield considerably. Hence an experiment was conducted in order to evaluate the optimum doses native tea-seed cake as natural pesticide for unwanted fishes. In this experiment, five treatments with concenteration of 2,4,6,8 and 10 ppm and with one control in triplicate group for each was considered. Three-hundred and seventy-eight young cray fish with an average weight of 4gr were randomly distributed between 18 fiberglass tanks of 400L capacity. Furthermore, one- hundred and eighty Carass fish (as competitors) with average weight of 4.6 gr were randomly distributed between all tanks. The dried tea-seed cake, first to be measured corresponding with volume of each tank and then were distributed to the required doses between all tanks. After fishes being adjacent to tea-seed cake, fish behavior and mortality were recorded at the end of different periods. Generally, considering price of tea-seed cake and its lethal dose, treatment four(8ppm) was shown reliable performance for eradicating unwanted fishes in Caspian Sea cray fish culture tank.