http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/88 2026-04-26T00:43:21Z 2026-04-26T00:43:21Z AHMED, KHALID http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/1062 2025-12-10T12:11:18Z 2024-12-01T00:00:00Z

CORROSION BEHAVIOR INVESTIGATION OF MARINE GRADE MILD STEELS IN THE BAY OF BENGAL WATER ENVIRONMENT AHMED, KHALID The corrosion behavior of marine-grade mild steels in seawater environments is a critical factor influencing the maintenance and longevity of marine structures such as vessels, offshore platforms, and coastal installations. Despite extensive research in various oceanic regions, the specific challenges posed by the Bay of Bengal (BoB) have not been fully explored, particularly for marine-grade steels. These steels, distinct in their alloying elements, may exhibit unique corrosion behaviors in the BoB's dynamic and chemically complex environment. This study aims to address this gap by investigating the corrosion behavior of two types of marine-grade mild steels, Grade A and Grade 907, under both static and dynamic conditions. The research employed laboratory-based experiments using gravimetric and electrochemical methods to measure corrosion rates of seamless and welded steel samples. These samples were immersed in seawater collected from multiple BoB locations, with exposure times ranging from initial immersion to extended submersion. Additionally, mechanical testing, including tensile strength and hardness assessments, was conducted to evaluate the degradation in material properties due to corrosion. Microstructural analysis using Optical and Scanning Electron Microscopy (SEM) revealed significant changes in the crystalline structure of the steel samples, indicating the extent of corrosion damage. Results indicate that dynamic conditions significantly accelerate corrosion rates, especially in deeper regions of the BoB, where the corrosion activity was higher than in coastal areas. Welded samples exhibited greater susceptibility to localized corrosion, suggesting a need for enhanced protective measures in these areas. The mechanical tests revealed a measurable reduction in hardness and more pronounced corrosion-induced damage in welded joints, highlighting the need for enhanced protection strategies in these marine areas. These findings highlight the necessity for region-specific corrosion protection strategies tailored to the unique environmental conditions of the BoB. By concentrating on the water composition of the Bay of Bengal, solutions to reduce corrosion in marine-grade mild steels particularly in this region can be developed. Also, a wider understanding of corrosion behavior in marine environments will come out. CORROSION BEHAVIOR INVESTIGATION OF MARINE GRADE MILD STEELS IN THE BAY OF BENGAL WATER ENVIRONMENT

2024-12-01T00:00:00Z HASSAN, MD.TAMIM ROHAN, AL SHAREAR HOSSAIN http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/861 2025-10-15T07:09:56Z 2024-03-01T00:00:00Z

DEVELOPMENT OF CONTROL SYSTEM FOR AN UNDERWATER ROV (REMOTELY OPERATED VEHICLE) FOR SURVEYING THE UNDERWATER PORTION OF THE SHIP HULL HASSAN, MD.TAMIM; ROHAN, AL SHAREAR HOSSAIN Underwater robotics is a rapidly growing field with applications in various industries such as oil and gas, marine biology, commercial activities like underwater inspection, and military etc. The hardware portion of underwater robotics is crucial for the successful operation of the robots in the harsh underwater environment. There are several types of control systems commonly used in underwater robotics such as Manual Control, Autonomous Control, Tele operation Control, Hybrid Control, Closed-Loop Control .In this project we are using manual control system includes following components: Control Station, Communication System, Sensors, Propulsion Systems, Power Management, PID control algorithm. The main aim of this thesis is to develop a cost-effective, efficient, and reliable control system for underwater robotics which would be able to maneuver the vehicle in six DOF with great ease. For this purpose we are not only focusing on controllability but also designing an efficient hull for serving our purpose and also optimized propeller using CFD technique. Motor were selected on the basis of the simulated thrust generated by propeller in ANSYS fluent software module. The methodology of underwater robotics involves a series of steps and process that are followed in a design, construction and operation. These steps typically include: requirements definition, design, prototype construction, testing and operation. DEVELOPMENT OF CONTROL SYSTEM FOR AN UNDERWATER ROV (REMOTELY OPERATED VEHICLE) FOR SURVEYING THE UNDERWATER PORTION OF THE SHIP HULL

2024-03-01T00:00:00Z LUBA, TABASSUMA TASNIM MIM, UMMA HONEY http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/860 2025-10-15T07:10:35Z 2024-02-01T00:00:00Z

DESIGN OF A GREEN SHIP FOR CONSERVATION OF ENVIRONMENT AT NIKLI HAOR IN BANGLADESH LUBA, TABASSUMA TASNIM; MIM, UMMA HONEY The Nikli Haor, encompassing the areas of Nikli, Mithamain, Austagram, and Itna upazilas in Kishoreganj district, is an extensive wetland. It appears as if numerous small islands and breathtaking natural formations are scattered across the vast water body, resembling isolated islets in a colossal watery expanse. During the rainy season, almost all these areas in the four upazilas of Kishoreganj—Nikli, Mithamain, Austagram, and Itna—are submerged in water, gradually receding as the rainy season concludes. During this time, the raised roads constructed for communication across the haor become visible. Previously, boat communication was prevalent during the rainy season, and people traversed from one place to another on foot during dry periods. However, times have changed, and with the development of infrastructure in these upazilas, all-weather roads and semi-metal roads have been built to facilitate communication. In the dry season, these areas witness rice cultivation and extensive livestock farming. Nevertheless, at present, the excessive use of engine-driven boats for transportation and the disposal of waste materials into the water by boat passengers are causing water pollution. This pollution, along with the impact of agricultural runoff and changes in the reproductive cycle of aquatic organisms, is adversely affecting the aquatic ecosystem. This research focuses on proposing a sustainable and environmentally friendly mode of transportation for travelers in the form of an indigenous amphibious vessel. The vessel aims to address issues related to the disposal of single-use plastics into the water by promoting the use of reusable and biodegradable plastic products. Additionally, the research suggests the implementation of decentralized wastewater treatment systems, hybrid engine systems, and the utilization of solar panels to reduce carbon dioxide emissions. Efforts are made to purify solid and liquid waste through the use of bio-gas production and bio-slurry treatment tanks. The decentralized wastewater treatment system ensures the use of bacteria-free water for various purposes or can be discharged without causing harm to the environment. The use of organic waste from the vessel in the form of bio-slurry can contribute to the production of bio-gas and serve as a nutrient-rich organic fertilizer, which can be sold for agricultural purposes. The adoption of hybrid engine systems and solar panels helps in reducing carbon dioxide emissions, making the model both environmentally sustainable and economically viable. Marine hybrid electric propulsion systems combine combustion engines with battery power to reduce emissions and optimize engine operation. They are suitable for vessels with varying power demands and flexible operating profiles. The successful implementation of this model not only benefits travelers but also makes the entire transportation system environmentally friendly. With the area's soil remaining unpolluted, dry-season activities such as rice cultivation and livestock rearing can thrive, resulting in economic prosperity. This model serves as an economically viable and environmentally sustainable solution. Design of A Green Ship for Conservation of Environment at Nikli Haor in Bangladesh

2024-02-01T00:00:00Z EMON, MD. EMAM HOSSAIN SHARIF AHAD, SHAH MD. NEWAZ http://dspace.mist.ac.bd:8080/xmlui/handle/123456789/859 2025-10-15T07:10:56Z 2024-03-01T00:00:00Z

DESIGN AND CONSTRUCTION OF AN ECONOMICAL UNDERWATER REMOTELY OPERATED VEHICLE (UROV) FOR SURVEYING UNDERWATER PORTION OF SHIP HULL & SHALLOW WATERWAYS EMON, MD. EMAM HOSSAIN; SHARIF AHAD, SHAH MD. NEWAZ Surveying underwater portion of ship hull is time consuming and costly as it is difficult to access and also poses a significant risk to human divers. To mitigate the problem, we have designed and constructed an economical underwater ROV. The ROV is made of lightweight materials to minimize weight and increase buoyancy. It is powered by a lithium-ion battery pack and is controlled by a tethered connection to a surface control unit. A raspberry pi-based control system is used to process, transmit and receive all information in the ROV. Overall eight thrusters are used to control the propulsion system. The ROV is capable to accomplish various rotational and flat movements in the water and it is equipped with a high-definition camera, a lighting system, and various sensors. The robot has the ability to navigate around the hull of the ship and capture high-quality images and data in real-time. The main application of the ROV is not only to inspect the underwater portion of ship hull but also shallow waterways. The ROV was tested in a controlled environment and performed well, providing clear and accurate images of the underwater environment. The ROV is expected to be a valuable tool for surveying ship hulls and shallow waterways, providing a cost-effective and efficient solution for underwater inspections. DESIGN AND CONSTRUCTION OF AN ECONOMICAL UNDERWATER REMOTELY OPERATED VEHICLE (UROV) FOR SURVEYING UNDERWATER PORTION OF SHIP HULL & SHALLOW WATERWAYS

2024-03-01T00:00:00Z