فصلنامه علوم و فناوری دریا
سال بیست و دوم شماره 86 (تابستان 1397)

During the past few decades, wave energy has received significant attention for harnessing ocean energy. Industry has proposed many topologies such as an oscillating water column, a point absorber, an overtopping system, and a bottom-hinged system. In particular, many researchers have focused on modeling the floating-point absorber, which is thought to be the most cost-efficient technology to extract wave energy. To model such devices, several modeling methods have been used such as the analytical method, the boundary-integral equation method, the Navier-Stokes equations method, and the empirical method. To assist the development of wave energy conversion (WEC) technologies, this report extensively reviews the methods for modeling the floating-point absorber

Today, many companies use thermal imaging (infrared) to prevent distorted locations and increase the reliability of power networks around the world. In fact, the technical inspection of the electrical equipment by the thermal cameras is the best way to troubleshoot. On the other hand, in all preventive methods as well as in the use of infrared imaging, the analysis and interpretation of thermal images are traditionally done. Hence, due to the wide variety, diversity and dispersion of power transmission networks, it is strongly felt to provide a method that intelligently detects the type of defect. In this paper, a method is proposed which, due to its lower cost and accuracy, can be intelligently detected by the use of thermal cameras in faults in power distribution networks, in order to reduce both the identification time and the error factor Minimized

In the present study, in an efficient and selective method, Thorin as a reagent was used by forming colour in the alkaline water–acetone media for direct spectrophotometric determination of lithium ion in the coastal seawater of Chabahar bay. Affective factors on the lithium-thorin complex formation reaction such as reaction time, concentration of thorin and the percent of potassium hydroxide and acetone were studied and optimized. Under optimum conditions, the limit of detection, linearity range relative and standard deviation of method were obtained as 0.039 mg/L, 0.10-1.3 mg/L, 9.11% (n =7), respectively and the average concentration of lithium in seawater of Chabahar Bay was estimated as 0.173 mg/L. Furthermore the effect of different depth on the dispersal of lithium in Chabahar Bay was investigated. The results showed that there were no significant differences among Li concentrations in different depths

Sea environmental conditions including wave and wind, influence the ship performance parameters like speed, safety, dynamics loads acting on ship srtucture and etc. ship motion prediction for proper vessel operational planning and utilization is considered by ship designers. In this article, motions of a trimaran ship in design speed are predicted by maxsurf software, 3D panel method. Besides, motions of trimaran ship are simulated by computational fluid dynamic (CFD) using Flow-3D software. In order to modeling the irregular waves in sea state 5, Bert schnider spectrum is used. 3D panel method calculations are implemented in frequency domain and CFD software calculations are implemented in time domain; then results are transformed from time domain to frequency domain by Fourier transform. for validation of calculations we used results of a reference tested model. according to achieved results the panel method is quiet well for investigation of trimaran motions and we can use it for complex hull forms and multihulls and in various maritime cases like wave encounter angle, ship speed and wave conditions

Nanoparticles as new emerging contaminant in body water cause stress response in aquatics and specially fishes that could affect physiological condition of fish and reduce their immune function. Hence the use of safety stimulators such as probiotics seems necessary. A total of 250 fry carp were divided for 42 days in three categories of without probiotics, probiotics level A (106) and fish probiotics Level B (107). Then each group exposed at 50% lethal concentration of nano-iron for 10 days. The serum biochemical parameters were then measured using an ELISA plate reader, SYSMEX device and the commercial kits. Probiotics alone hadn’t significant effect on glucose, direct and total bilirubin (0.05≤P), but had a significant effect on the protein and leads to reduce this index. Nano iron increased protein and decreased direct and total bilirubin (P≤0.05), but had no significant effect on glucose. The combined use of probiotics and nano iron caused a sharp decline of direct and total bilirubin and increase the protein (P≤0.05), but had no significant effect on glucose index (0.05≤ P). In general, probiotics and iron compound lead to reduce and mitigate the protein and reduce the escalating effects of nano irons on this index. But there was no significant effect of probiotics on three indices of glucose, total and direct bilirubin

The beaches anywhere in the world are important sources of development and capability. The beaches of the Oman Sea are one of the most diverse coastal areas in Iran. Access to the Free Sea and the features of the coastal geographic environment are the easiest potentials that are prepared for planning and development. His research has been conducted with a view to assessing the potential of the natural environment of the coastal coast of Oman for coastal tourism planning. The method of fieldwork and analysis is based on meteorological and geomorphological data. For this purpose, using the 10 biologic indexes, we first evaluated the desirable times and appropriate chapters of tourism. Then, every season, it was planned to plan various types of tourism, such as geo-tourism and sports tourism. The results showed that for at least four months from the year, the ideal climatic conditions for the use of potentials on the banks of the Oman, including swimming, diving, kite riding, sailing at sea, and 5 months of using the beach, such as geo-tourism visits such as miniaturized mountains, are suitable. Coastal tourism can be the most important tourist activity in the region

Everyday, 13 accidents occour in our country’s petrochemical industry that unfortunately with human death. The aim of this research is identify and rank risks and factors can damage to Khark Island petrochemical Jetty. The tesearch has application nature and with using study of national and international articles, risks identified. Then use filled questionnaiers by 35 person of HSE experts, Jetty authority, assistance of manager in Khark Island petrochemical and captain of a damaged ship in this jetty to rank of risks at FMEA model in 4 aspects of occurrence possibility, severity, detention and RPN. Findings of resarch show Electrified one and three phase switchgear are have most rank in terms of RPN