فصلنامه علوم و فناوری دریا
سال نوزدهم شماره 76 (زمستان 1394)

The optimization of propeller has always been one of the most important aspects of propeller design. Reducing fuel consumption is also an important aspect of ship and propulsion system design to reduce the costs. The proposed design methodology represents a new approach to evaluate the propeller design of a military by considering the various missions. So three different modes propulsion system, e.g. Trial, Half and Full modes in which, respectively, one, two and four propulsion motors are used will be considered. Also the propeller using genetic algorithm is optimized by considering the fuel consumption along with system performance characteristics and constraints such as trust, torque, stress, cavitation, efficiency and skew angle to the best forward speed with minimum fuel consumption is resulted.

Range finders are one of the most important devices that are used for controling the height of robots from bottom of the underwater environment to avoid collision with it. In this paper firstly took a simulation processing on received echo signal by using Matlab software. Then made a description about implementation process of the cross-correlation algoritm in FPGA, verified received echo signal and recognition between noise signal and main echo signal is perform by adaptive noise threshold method. The advantages of using this method is to simplify complex processing that previous robots have been used to find the distance between them and sea bottom. This method is also compatible with the change of environment noise and that is one of the considerable point which this paper present.

Erosion around the piers is one of the main causes of the destruction of bridges, docks and other similar structures. Using of methods such as cross-section of pier, applying the slot on pier or combination of them, is the preparations which recommended to control and reduce the scour depth around the bridge piers. The purpose of this study is to investigate the effect of applying double slot in decreasing the local scour in comparison to the no slot pier and on slot piers. In this regard, the three dimensional simulation of flow field around cylindrical bridge piers has been conducted by Fluent and the effect of each of models based on behavior of flow field and the bed shear stress is studied. Done modeling showed the positive impact of combination of the bed slot and water surface slot on decreasing the bed shear stress and also the extension of critical shear stress. The reducing of bed shear stress around pier with double slot is 65% compared to the no slot and one slot pier. Also applying the slot in piers can be decrease the power of wake vortices. By comparison the velocity profile before the pier, variation of water surface and the extension of critical bed shear stress, the high precision of RSM turbulence model was concluded.

More than 90% of world trade is done by maritime transportation, so its safety is one of the most important points that should be considered.
Aids to navigation are using to increase safety of waterways of ports. For supervision to AtoN, there are two systems.
1. Traditional system
2. Remote control system
This thesis investigate and compare traditional system and remote control system¸ studies the role of remote control system of aids to navigation in improvement safety of ports and then choose the best system for the monitoring of Aids to Navigation. Method of this thesis is descriptive survey and in view of goal is applied. For data collection for this thesis, use from the following methods. Eye witness-directly see and interview with experts- resource library- studies and research that done in this field-world wide web. With respect to result the benefit of remote control system is: rapid return on investment-increase the quality of services about aids to navigation marks-increase reliability and justifiability of data-decrease of operational cost-increase the safety of water ways.

This paper presents a review on commercial vessel generated waste. In this context various ship waste categories are identified (oily wastes, Black water, Grey water, Ballast water, Garbage, Air emission), their variation between different vessel types is pinpointed and the legal framework and guidelines for their management and handling are drafted adequately. Ship waste shall be refer to any harmful substance (for both the marine environment and the public health), which is generated during the usual day-to-day ship operation. Past experience has proven that these wastes accumulate significant quantities and therefore potential for marine pollution. Thus, only after recent significant environment damage (e.g. in Alaska, the Caribbean Sea etc) has occurred, did the international maritime community turn its attention on the matter. Only Through an international marine forum marine pollution from ships can be satisfactorily tackles. That forum is the International Maritime Organization (IMO) whose twin objectives are maritime safety and the prevention of marine pollution caused by ships. Finally, more attention should be calculated to ship waste streams, monitoring of the illegal outputs and ship waste reception facilities on the beach with a common framework, to be proposed.

Ports need to keep on your current customers and attract new customers due to their activities nature (national and international), massive investment for port establishing and globalization(increase competition between ports in national and international level). our country has large Land and sea border, Strategic Position, accessibility to open seas and take advantage of multimodal transport system, it can play role as important transit course in local and global level and use it in best manner.Chabahar port has special position in Iran trade with other countries because it has strategic position and access to international open seas. also, this port close to Afghanistan, Pakistan, Middle Asia, and in future with join to Iran railroad system can gain special role in transit cargo to them. this port for maintaining its current market and increase its share in national and local level, use marketing techniques as effective solution to contact customers. Among marketing activities, Advertisement that account as one part of it, mostly emphasis on port preference. Six factors affecting on port advertisement: Human resources, Budget, tools, Technology, port features and regulations. Result of this paper showed port features and budget are 2 main factor effect in implement and quality of chabahar port's marketing advertisement.