Ocean Engineering Commons^™

Hydrogen Absorption Induced Slow Crack Growth In Austenitic Stainless Steels For Petrochemical Pressure Vessel Industries, Ronnie Higuchi Rusli

Makara Journal of Technology

Type 304L and type 309 austenitic stainless steels were tested either by exposed to gaseous hydrogen or undergoing polarized cathodic charging. Slow crack growth by straining was observed in type 304L, and the formation of α‘ martensite was indicated to be precursor for such cracking. Gross plastic deformation was observed at the tip of the notch, and a single crack grew slowly from this region in a direction approximately perpendicular to the tensile axis. Martensite formation is not a necessary condition for hydrogen embrittlement in the austenitic phase.

Development Of Technology Parameter Towards Shipbuilding Productivity Predictor Using Cubic Spline Approach, Bagiyo Suwasono, Sjarief Widjaja, Achmad Zubaydi, Zaed Yuliadi, I Nyoman Budiantara

Makara Journal of Technology

Development of Technology Parameter Towards Shipbuilding Productivity Predictor Using Cubic Spline Approach. Ability of production processes associated with state-of-the-art technology, which allows the shipbuilding, is customized with modern equipment. It will give impact to level of productivity and competitiveness. This study proposes a nonparametric regression cubic spline approach with 1 knot, 2 knots, and 3 knots. The application programs Tibco Spotfire S+ showed that a cubic spline with 2 knots (4.25 and 4.50) gave the best result with the value of GCV = 56.21556, and R2 = 94.03%.Estimation result of cubic spline with 2 knots for the PT. Batamec shipyard …

Shaft Torsional Vibration Response Of Vertical Axis Ocean Current Turbine Model Due To Torque Excitation, Adi Wirawan Husodo, I Ketut Aria Pria Utama, I Made Ariana

Makara Journal of Technology

Shaft Torsional Vibration Response of Vertical Axis Ocean Current Turbine Model Due to Torque Excitation. The current research aimed to study the torsional vibration response of Vertical Axis Ocean Current Turbine due to randomly torque excitation pattern, owing to the variety of ocean current velocity. The turbine model is composed of 3 aluminum blades of NACA 0018 connected to steel shaft. Turbine dimensions are 10 cm of chord, 1.8 cm of chamber and 100 cm of span. The variation of ocean current velocity is 0.5 m/s, 1.0 m/s, 1.5 m/s, 2.0 m/s, 2.5 m/s and 3.0 m/s. The Model has …

Autonomous Underwater Vehicles As Tools For Deep-Submergence Archaeology, Christopher N. Roman, Ian Roderick Mather

Graduate School of Oceanography Faculty Publications

Marine archaeology beyond the capabilities of scuba divers is a technologically enabled field. The tool suite includes ship-based systems such as towed side-scan sonars and remotely operated vehicles, and more recently free-swimming autonomous underwater vehicles (AUVs). Each of these platforms has various imaging and mapping capabilities appropriate for specific scales and tasks. Broadly speaking, AUVs are becoming effective tools for locating, identifying, and surveying archaeological sites. This paper discusses the role of AUVs in this suite of tools, outlines some specific design criteria necessary to maximize their utility in the field, and presents directions for future developments. Results are presented …

Methodology To Quantify Vertical Accelerations Of Planing Craft In Irregular Waves, Jennifer Suzanne Grimsley

Mechanical & Aerospace Engineering Theses & Dissertations

Planing craft operating in waves at high speeds can experience high, repetitive vertical accelerations that are random and nonlinear in relation to the sea condition. A proper understanding of vertical accelerations is critical to meet statistically based criteria for structural design, habitability, and equipment selection. Historically, it was assumed that planing craft vertical accelerations fit the Exponential distribution, and design methods adopted this conclusion. However, several published papers have raised doubts regarding the accuracy and validity of this Exponential distribution assumption.

The statistical behavior of planing craft vertical accelerations are examined for the Parent and Peak data sets from twenty-eight …

Turbulence Measurement With Coherent Doppler Sonar, Jeremy Dillon

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

The ocean has been described as Earth's "fi nal frontier" in a vision statement on ocean exploration (National Oceanic and Atmospheric Administration, 2000). The search for new insight is motivated by the fact that our environmental and economic security depends critically on the ocean and the freshwater bodies that drain into it. As the vast majority of the ocean is unknown and unexplored, there is great potential for scientifi c discovery beneath the sea surface (McNutt, 2002). The development of remote and in situ sensors forms a cornerstone of this vision for exploring ocean dynamics at new scales.

Laminar Flow Past An Oscillating Circular Cylinder In Cross Flow, Pham Anh-Hung, Lee Chang-Yeol, Seo Jang-Hoon, Chun Ho-Hwan, Kim Hee-Jung, Hyun-Sik Yoon, Dong-Woo Park, Il-Ryong Park

Journal of Marine Science and Technology–Taiwan

The present study numerically investigates the twodimensional laminar flow past a circular cylinder forced to oscillate transverse to the free-stream. The numerical simulations are performed at a various range of cylinder oscillation frequency ranged between 0.8 and 1.2 of the natural vortex shedding frequency, and the oscillation amplitude extended up to 50% of the cylinder diameter at one Reynolds number of 185 showing the typical two-dimensional vortex shedding. The immersed boundary method is used to handle the oscillating cylinder in a rectangular grid system using the finite volume method. The primary vortex shedding frequency has the same value with the …

Application Of Structured Light Imaging For High Resolution Mapping Of Underwater Archaeological Sites, Chris Roman, Gabrielle Inglis, James Rutter

Graduate School of Oceanography Faculty Publications

This paper presents results from recent work using structured light laser profile imaging to create high resolution bathymetric maps of underwater archaeological sites. Documenting the texture and structure of submerged sites is a difficult task and many applicable acoustic and photographic mapping techniques have recently emerged. This effort was completed to evaluate laser profile imaging in comparison to stereo imaging and high frequency multibeam mapping. A ROV mounted camera and inclined 532 nm sheet laser were used to create profiles of the bottom that were then merged into maps using platform navigation data. These initial results show very promising resolution …

Wave Energy Converter Performance Modeling And Cost Of Electricity Assessment, Dmitri Jarocki

Master's Theses

California is experiencing a rapid increase in interest for the potential of converting ocean waves into clean electricity. Numerous applications have been submitted for the permitting of such renewable energy projects; however the profitability, practicability, and survivability have yet to be proven. Wave energy conversion technology has steadily matured since its naissance in the 1970’s, several wave energy power installations currently exist, and numerous plans for commercial power plant are in the works on the shores of multiple continents. This study aims to assess the economic viability of two proposed commercial wave energy power plant projects on the Central California …

Ontology-Based Automatic Classification For News Articles In Indonesian Language, Prajna Wira Basnur, Dana Indra Sensuse

Makara Journal of Technology

Ontology-Based Automatic Classification for News Articles in Indonesian Language. Searching specific information will be difficult if relying only on query. Choosing less specific queries will result in a lot of irrelevant information fetched by the system. One of the most successful ways to overcome this problem is to perform document classification based on the topic. There are many methods that can be used to conduct such a classification, such as using statistical and machine learning approaches. However, those document classification methods require training the data or learning the documents. In this study, the authors attempted to classify documents using a …

A Simple Technique For Surface Area Determination Through Supercritical Co2 Adsorption, Mahmud Sudibandriyo

Makara Journal of Technology

The measurement of specific surface area of porous materials has long been important in physical sciences and is currently growing in importance in applied and environmental science. Numerous systems have been developed for surface area measurement by gas adsorption. Commercial systems are available which can measure a wide range of absolute surface area with relative ease. However, their cost is often prohibitive. In this study, an inexpensive apparatus for surface area measurement has been set up to be used for measuring supercritical adsorption of CO2. The Ono-Kondo Lattice model was used to represent the adsorption isotherm and to determine the …

Fishing Catch And Catch Rate Assesment Of Mini Trawl, Trapnet And Setnet Fisheries, Muhammad Firdaus

Makara Journal of Technology

Fishing Catch and Catch Rate Assesment of Mini Trawl, Trapnet and Setnet Fisheries. This paper is aimed at assessing fishing catch and catch rate of the dragged gear on shrimp, trapnet, and setnet fisheries in Tarakan. The catch and effort data (number and species) and the fishing time of captured units were used in this qualitative analysis of fishing catch and catch rate to describe catch composition and catch rate from three catch fishery units in Tarakan. The result of the research shows that in the catching operation the dragged gear on shrimp has two main catch targets, which are …

Particle Filter With Binary Gaussian Weighting And Support Vector Machine For Human Pose Interpretation, Indah Agustien, Muhammad Rahmat Widyanto, Sukmawati Nur Endah, Tarzan Basaruddin

Makara Journal of Technology

This paper proposes human pose interpretation using particle filter (PF) with Binary Gaussian Weighting and support vector machine (SVM). In the proposed system, particle filter is used to track a human object, then this human object is skeletonized using thinning algorithm and classified using SVM. The classification is to identify human pose, whether it is normal or abnormal behavior. Here particle filter is modified through weight calculation using Gaussian distribution to reduce the computational time. The modified particle filter consists of four main phases. First, particles are generated to predict target’s location. Second, the weight of certain particles is calculated …

Marine Current Energy Devices: Current Status And Possible Future Applications In Ireland, Fergal O'Rourke, Fergal Boyle, Anthony Reynolds

Articles

There is a growing demand for the use of renewable energy technologies to generate electricity due to concerns over climate change. The oceans provide a huge potential resource of energy. Energy extraction using marine current energy devices (MCEDs) offers a sustainable alternative to conventional sources and a predictable alternative to other renewable energy technologies. A MCED utilises the kinetic energy of the tides as opposed to the potential energy which is utilised by a tidal barrage. Over the past decade MCEDs have become an increasingly popular method of energy extraction. However, marine current energy technology is still not economically viable …

Maintenance Activity Planning By Reability Centered Maintenance Ii Method, Rachmad Hidayat, Nachnul Ansori, Ali Imron

Makara Journal of Technology

Maintenance Activity Planning by Reability Centered Maintenance II Method. This research discusses maintenance activity planning using the RCM II method to evaluate failure function risk on compresor screw. The calculation of maintenance time is performed by considering maintenance and repair costs. The risk evaluation result with RPN shows that the critical component that needs to get the main priority in applying maintenance on compresor screw is function disorder on timeworn piston and on the broken outgoing air sponge’s filter that receives RPN 45. The optimum maintenance time calculation is applied on components that undergo scheduled restoration and scheduled discard task …

Software Design Of Mobile Antenna For Auto Satellite Tracking Using Modem Correction And Elevation Azimuth Method, Djamhari Sirat, Muhamad Asvial, Arman Djohan Diponegoro, Himawan Sidharta

Makara Journal of Technology

Software Design of Mobile Antenna for Auto Satellite Tracking Using Modem Correction and Elevation Azimuth Method. Pointing accuracy is important in satellite communication. Because the satellite’s distance to the surface of the earth's satellite is so huge, 1 degree of pointing error will make the antenna unable to send data to satellites. To overcome this, the auto-tracking satellite controller is made. This system uses a microcontroller as the controller, with the GPS as the location indicator of the antenna, a digital compass as the beginning of antenna pointing direction, a rotary encoder as azimuth and elevation censor, and a modem …

Petroleum Degradation In Soil By Thermophilic Bacteria With Biopile Reactor, Astri Nugroho, Edison Effendi, Yulius Karonta

Makara Journal of Technology

Crude oil degradation has been carried out using biopile reactor in total petroleum hydrocarbon (TPH) concentration of 5%, 10% and 15%. The thermophilic microorganisms used from isolation result and identification are Aeromonas salmonicida, Bacillus pantothenticus, and Stenotrophomonas maltophilia. The biodegradation of biopile reactor is done by various concentrations of TPH, total plate count (TPC), and volatile suspended solid (VSS) per day for 30 days. The biodegradation of kinetic parameter calculated consists of μ, μm, Y, Yt, Yobs, Kd, Ks from TPH concentration decision, and TPC and VSS in every microorganism with t (observation time) of 0 hour to 168 hours. …

Ergonomic Analysis Of Ui’S Bicyclesusing Posture Evaluation Index (Pei) Method In Virtual Environment, Erlinda Muslim, Boy Nurtjahyo, Zulkarnain Zulkarnain, Liza Afrinotha

Makara Journal of Technology

Ergonomic Analysis of UI’s Bicycles Using Posture Evaluation Index (PEI) Method in Virtual Environment. This research was conducted to study the ergonomic aspect of University of Indonesia’s bicycles in virtual environment. Software Jack 6.0 was used to analyze it. PEI was used as an approach that integrated the results of three methods: lower back analysis (LBA), ovako working posture analysis (OWAS), and rapid upper limb assessment (RULA). The research objective is to evaluate the existing design of University of Indonesia’s bicycles and to determine the most ergonomic redesign which concerns handlebar height and saddle height modification. The result showed that …

Tidal Energy Update 2009, Fergal O'Rourke, Fergal Boyle, Anthony Reynolds

Articles

Tidal energy has the potential to play a valuable part in a sustainable energy future. It is an extremely predictable energy source, depending only on the gravitational pull of the moon and the sun and the centrifugal forces created by the rotation of the earth-moon system. Tidal energy has been exploited on a significant scale since the construction of the La Rance tidal barrage in France in 1967. A tidal barrage utilises the potential energy of the tide and has proven to be very successful, despite opposition from environmental groups. Kinetic energy can also be harnessed from tidal currents to …

Robust Observers And Controllers For Marine Surface Vessels Undergoing Maneuvering And Course-Keeping Tasks, Nassim Khaled

Wayne State University Dissertations

The dynamic behavior of marine surface vessels is highly nonlinear. Moreover, it is significantly influenced by environmental disturbances induced by winds, random sea waves and currents. To yield a desired response of the ship, the guidance and control system of the ship should be robust to both modeling imprecision and significant environmental disturbances.

The focus of the current work is threefold. First, a six degree-of-freedom nonlinear model for a marine surface vessel is developed. It accounts for the coriolis and centripetal acceleration terms, added mass and wave damping terms, wave excitation forces, so-called "memory" effect terms, nonlinear restoring forces, wind …

Investigation And Modeling Of Ice Fracture In Cold Ocean Engineering Applications, Rocky S. Taylor

Link Foundation Ocean Engineering and Instrumentation Fellowship Reports

Ice conditions present a significant challenge in the design of ships and structures for the development of offshore energy resources in cold ocean environments. Many regions throughout the world including Alaska, Canada, Russia, Norway, Kazakhstan and China are developing offshore energy resources in ice-prone environments. The growth and stability of the global economy is closely linked to that of our energy supply, and offshore industrial activity in Northern regions has increased significantly in recent years. One of the most significant engineering challenges when designing structures for ice environments is the estimation of design ice loads. The design load scenario for …

Laboratory Generation And Physics Of Propagation Of Solitary Waves And Water Surface Depressions, Siamak Malek Mohammadi

All Dissertations

Solitary waves and water surface depressions are generated using a piston-type wavemaker. Different aspects of their propagation including profile evolution, establishment rate, stability, and celerity are examined experimentally.
Traditionally, solitary waves are generated in laboratory set-ups using a methodology developed by Goring (1979) that considers a wave of permanent form during the generation process. A New methodology for generation of solitary waves using piston-type wavemakers is proposed by considering the evolving nature of the wave during generation phase. The capability of the New methodology in generation of solitary waves is assessed by conducting a series of laboratory experiments in water …

Effects Of Ph On Calcium Carbonate Precipitation Under Magnetic Field, Nelson Saksono, Yuliusman Yuliusman, Setijo Bismo, Roekmijati W. Soemantojo, Azwar Manaf

Makara Journal of Technology

Magnetic field effect on CaCO3 precipitation is the key parameter in evaluating the effectiveness of Anti-scale Magnetic Treatment (AMT). The purpose of this study was to investigate magnetic fields influence on CaCO3 precipitation in high and low super-saturated CaCO3 solution by varied pH CaCO3 solution using circulation flow fluid system. The observation results in the high super saturated solution (pH 8.5) showed the increase of precipited CaCO3 in magnetized solutions compared to those in non-magnetic solution during circulation process. In the low super-saturated CaCO3 solution (pH 6.4) it was found that magnetic treatment increased CaCO3 precipitation after circulation process. In …

Intermetallic Cu3sn Phase Layer On Electrode’S Tip Of Galvanized Resistance Spot Welding, Muhammad Anis, Aulia Irsyadi, Deni Ferdian

Makara Journal of Technology

Intermetallic Cu3Sn Phase Layer on Electrode’s Tip of Galvanized Resistance Spot Welding. A resistance spot welding method is commonly used in automotive industries application. In a resistance spot welding method, the copper electrode has a significant role as an electric current carrier for joining thin metal sheet. This research was focused on studying the effect of tin layer at the electrode tip for joining galvanized steel sheet. The main variable of this research is in the thickness of the intermetallic Cu3Sn layer. The result showed that the introduction of tin layer less than 1 μm in thickness on the electrode …

Semi-Automatic Image Segmentation For Volumetric Visualization Of Pelvis Ct Scan-Images, Suprijanto Suprijanto, Farida I. Muchtadi, Irwan Setiawan

Makara Journal of Technology

Semi-Automatic Image Segmentation for Volumetric Visualization of Pelvis CT Scan-Images. The current development of computerized tomography (CT) has enable us to obtain cross sectional image using multi slicing techniques in an order of few seconds. The obtained images represent several tissue structures on cross section slice being imaged. One challenge to help diagnosis using CT images is extracting an anatomic structure of interest using a method of image segmentation and volumetric visualization with the assistance of computers. In case of volumetric visualization of pelvis bones extracted from multi-slice CT images, whole images which are containing part of pelvis bone structures …

Implementation Of Six Sigma Method To Maintain The Quality Of Construction Projects, Yusuf Latief, Retyaning Puji Utami

Makara Journal of Technology

Implementation of Six Sigma Method to Maintain The Quality of Construction Projects. Six sigma (6-sigma) is a method that widely developed in the world, especially in manufacturing industry to decrease failures in achieving good quality in construction projects. The objective of this research is to explore the existing condition of quality management and the aplication of 6-sigma method in maintaining quality of construction projects. Structured interviews to experienced experts and people who were recommended by their companies were conducted. Non-parametric analysis using frequencies distribution procedures were used for analysis. The result shows that existing condition in quality management of construction …

Simple Ml Detector For Multiple Antennas Communication System, Ahmad Taqwa, Soegijardjo Soegijoko, Sugihartono Sugihartono, Suhartono Tjondronegoro

Makara Journal of Technology

Simple ML Detector for Multiple Antennas Communication System. In order to support providing broadband wireless communication services against limited and expensive frequency bandwidth, we have to develop a bandwidth efficient system. Therefore, in this paper we propose a closed-loop MIMO (Multiple-Input-Multiple-Output) system using ML (Maximum Likelihood) detector to optimize capacity and to increase system performance. What is especially exciting about the benefits offered by MIMO is that a high capacity and performance can be attained without additional frequency-spectral resource. The grand scenario of this concept is the attained advantages of transformation matrices having capability to allocate transmitted signals power suit …

Mechanical Properties Of Ramie Fiber Reinforced Epoxy Lamina Composite For Socket Prosthesis, Tresna P. Soemardi, Widjajalaksmi Kusumaningsih, Agustinus Purna Irawan

Makara Journal of Technology

Mechanical properties of ramie fiber reinforced epoxy lamina composite for socket prosthesis. This paper presents an investigation into the application of natural fiber composite especially ramie fiber reinforced epoxy lamina composite for socket prosthesis. The research focuses on the tensile and shear strength from ramie fiber reinforced epoxy lamina composite which will be applied as alternative material for socket prosthesis. The research based on American Society for Testing Material (ASTM) standard D 3039/D 3039M for tensile strength and ASTM D 4255/D 4255M-83 for shear strength. The ramie fiber applied is a fiber continue 100 % Ne14'S with Epoxy Resin Bakelite …

Potency Of Thermoelectric Generator For Hybrid Vehicle, Nandy Putra, Raldi Artono Koestoer, Mohammad Adhitya, Ardian Roekettino, Bayu Trianto

Makara Journal of Technology

Potency of Thermoelectric Generator for Hybrid Vehicle. Thermoelectric Generator (TEG) has been known as electricity generation for many years. If the temperature difference occurred between two difference semi conductor materials, the current will flow in the material and produced difference voltage. This principle is known as Seebeck effect that is the opposite of Peltier effect Thermoelectric Cooling (TEC). This research was conducted to test the potential of electric source from twelve peltier modules. Then, these thermoelectric generators were applied in hybrid car by using waste heat from the combustion engine. The experiment has been conducted with variations of peltier module …

Performance Of Hollow Fiber Membrane Gas-Liquid Contactors To Absorb Co2 Using Diethanolamine (Dea) As A Solvent, Sutrasno Kartohardjono, Pan Ade Nata, Eko Prasetio, Yuliusman Yuliusman

Makara Journal of Technology

This study uses DEA solution to absorb CO2 from the gas flow through the hollow fiber membrane contactors. This study aims to evaluate the performance of hollow fiber membrane contactors to absorb CO2 gas using DEA solution as solvent through mass transfer and hydrodynamics studies. The use of DEA solution is to reduce the mass transfer resistance in the liquid phase, and on the other side, the large contact area of the membrane surface can cover the disadvantage of membrane contactors; additional mass transfer resistance in the membrane phase. During experiments, CO2 feed flows through the fiber lumens, while the …