Ocean Engineering Commons^™

Influence Of Boundary Conditions And Internal Fluid Types On Dynamic Characteristics Of A Deepwater Riser, Lei Guo, Zong-Ming Zhu, Zhong-Jian Pan, Zhi-Ming Guo

Journal of Marine Science and Technology–Taiwan

Deepwater Steel Catenary Riser (DSCR) is the key structure of oil and gas production system in the ocean. To design an optimized DSCR system, the dynamic characteristics of the DSCR are analyzed by setting some different boundary condi-tions and internal fluid types. The main vibration mode of the DSCR is found orthogonal to both mass and stiffness according to the normalization condition of the main mode, and then the regular mode function and the jth order principal stiffness Kpj are obtained. Under different initial conditions, the transverse responses of DSCR represented by regular coordinates under arbitrary excitation are obtained. Then, …

Variance Of Td-Mosaic Dual-Vortex Interactions Between In-Fa And Cempaka (2021) In The North Pacific, Tsorng-Lin Chia, Guang-Yang Pan, Ji-Chyun Liu

Journal of Marine Science and Technology–Taiwan

A study of the different types of dual-vortex interactions or “Fujiwara effects” between two storms is crucial for considerably improving weather forecasts. This study combined remote sensing images, empirical formulas based on the possibility of storm interaction (Liou–Liu formula), and vector addition techniques to accurately analyze In-Fa and Cempaka typhoons and the surrounding weather patterns during the 2021 typhoon season in the North Pacific. Although the distance separating the typhoons In-Fa and Cempaka was 1,800–2,040 km, the influence of middle air flow and a tropical depression (TD) caused a "vector superposition TD-mosaic double-vortex" interaction between the two typhoons. Therefore, this …

Optimal Deployment Of Flood Emergency Response Materials Under Stochastic Demands, Shangyao Yan, Jenn-Rong Lin, Chia-Fu Ku

Journal of Marine Science and Technology–Taiwan

This study aims to develop a planning model for the deployment of flood emergency response materials under stochastic demands. For ease of modeling, a deterministic demand model is first proposed, from which the stochastic model is further extended. These models are used to determine the allocation of materials the transport truck routes and distribution of the stockpiled materials to emergency sites. The models are formulated as multiple integer network flow problems with special side constraints which are characterized as NP-hard in terms of optimization. To solve the complicated stochastic model efficiently, we also develop a solution algorithm based on a …

Ballasting System For An Autonomous Underwater Vehicle, Noura Rayes, Bahram Nassersharif, Zach Champney, Kyle Alessandro, Jason Mirandou

Senior Honors Projects

NOURA RAYES (Mechanical Engineering); Ballasting System for an Autonomous Underwater Vehicle Sponsor: Bahram Nassersharif (Mechanical Engineering)

Over the last year, our Mechanical Engineering Capstone team, Nautilus, has been working to design a ballasting system for various Autonomous Underwater Vehicles (AUVs) sponsored by Raytheon Technologies. Common AUV systems are used for a wide range of applications from environmental monitoring, oceanic exploration, to data collection. AUVs also have many technical advantages that make underwater tasks more efficient, cost-effective, and generally safer. Raytheon Technology, specifically, is looking to improve their existing ballasting mechanism for their AUVs to use for military defense. For this …

Investigating The Application Of Flettner Rotors On The Great Lakes, Garrett C. Bond

Senior Honors Theses

Climate change is quickly becoming one of the leading problems of the twenty-first century, and the maritime transportation sector is beginning to react. Wind propulsion technologies have been making a comeback led by the Flettner rotor. The deck-mounted, vertical, spinning cylinder generates a lift (or thrust) force perpendicular to the wind by utilizing the Magnus effect. Rotor performance has been studied extensively on many ocean shipping routes, but has not been on the Great Lakes, a region with a large maritime industry. This study aims to assess whether or not Flettner rotors are practical in the region by calculating propulsive …

Enhancement Of Biogas Production Through Solid-State Anaerobic Co-Digestion Of Food Waste And Corn Cobs, Lukhi Mulia Shitophyta, Anisa Salsabila, Firanita Angraini Putri, Siti Jamilatun

Makara Journal of Technology

Although biogas has been primarily produced through liquid anaerobic digestion, this method leads to the floating and stratification of fibers and non-homogeneous mixing, which can reduce the biogas yield. Alternatively, biogas can be produced by the solid-state anaerobic digestion (SS-AD) of organic material with a high solid content, such as corn cobs. We investigated the co-digestion of food waste and corn cobs as a biomass feedstock for SS-AD in biogas production. We measured the effects of the total solid (TS) content, percentage of food waste, and reduction in volatile solids (VS), from which we determined its appropriate kinetic model. We …

Control Strategy For Solar Energy-Saving Lamps For Optimized Energy Utilization And Sustainability Of Operation Durability: Indonesia Case, Burhanuddin Halimi, Agus Purwadi, Nana Heryana

Makara Journal of Technology

To solve the electrification ratio issue, the Indonesian government has promoted the use of solar energy-saving lamps. This study proposes a control strategy that adopts current reference time-based profiling for solar energy-saving lamps. For optimal energy consumption, the current reference profile is determined according to users’ daily energy requirements. From the aspect of user comfort, a gradual step reference profile is also introduced to provide a subtle change in lighting intensity level. The proposed control strategy can minimize energy consumption and optimize the operation durability of the system. The concept is verified by simulating four scenarios, the results of which …

A Non-Iteration Solution For Solving The Backward-In-Time Two-Dimensional Burgers’ Equation With A Large Reynolds Number, Yen-Shen Chang, Yung-Wei Chen, Chein-Shan Liu, Jiang-Ren Chang

Journal of Marine Science and Technology–Taiwan

This article proposes a noniteration solution based on the Lie-group shooting method (LGSM) to solve the backward-in-time two-dimensional Burgers’ equation with a large Reynolds number. The backward problem is famous for seriously ill-posed cases because the solution is generally unstable and highly dependent on the input data. Small perturbations in the input data, such as random errors inherent to the measurements in the analysis, can cause large oscillations in the solution. To handle a large Reynolds number under long time spans, it is very difficult to integrate towards the time direction. To avoid time integration and numerical iteration, the noniteration …

Polyketides And Terpenes In Marine Microalgae: Ecological Roles And Mechanisms Of Biosynthesis, Yunxuan Xie, Mohammad Elsheikh

Journal of Marine Science and Technology–Taiwan

Marine microalgae comprise a large number of polyketides and terpenes identified to date with highly diverse molecular scaffolds and the biological activities (Kalaitzis et al., 2010). These compounds play significant roles in marine food web and nutraceutical supplementation in marine animals. Compounds of this class are often synthesized by gene clusters with dedicated domains responsible for carbon chain extension and modification. The unique molecular structure of these compounds encourages people to investigate their biosynthetic mechanisms in-depth. In this review, we summarize relevant articles to unravel the shared mechanisms of these compounds to further understand the variety of domain organizations and …

Unbaited Light-Emitting Diode Traps Performance For Catching Orange Mud Crabs, Muhamad Naimullah, Kuo-Wei Lan, Mhd Ikhwanuddin, Adnan Amin-Safwan, Wei-Yu Lee

Journal of Marine Science and Technology–Taiwan

Mud crabs (Scylla spp.) are a vital fishery resource and targeted for a valuable source of income for coastal communities throughout the Indo-Pacific region. Baited traps are a considerable expense in crustacean fishing. Hence, the present study was performed to investigate the catchability of Scylla olivacea in response to light-emitting diodes (LEDs) in captivity and field conditions. We used a new experimental setup in the captivity condition that revealed most S. olivacea were attracted to green, blue, and white LED lights and no attractive effect by red LED lights similar to the controls. Field studies have shown that the catch …

Catch And Effort Standardization For Taiwanese Swordtip Squid Uroteuthis Edulis Fisheries In The Southern East China Sea, Ke-Yang Chang, Yu-Jie Hsu, Tzu-Yun Ching, Cheng-Hsin Liao, Chih-Shin Chen

Journal of Marine Science and Technology–Taiwan

The swordtip squid Uroteuthis edulis is a neritic squid species that is widely distributed within the coastal waters of subtropical and tropical Indo-western Pacific regions. This squid is a commercially important species throughout its distribution range and plays a critical role in marine ecosystems. Stock assessments of the squid in the East China Sea (ECS) are scarce, although it is crucial information for the sustainability of the squid and relevant fisheries. The squid was harvested by various fisheries in the southern ECS, which could restrict methods for catch-effort standardization. In this study, catch-effort data of Taiwanese swordtip squid fisheries in …

Uniform Torsion Analysis Of Composite Shafts Using Point Collocation Method Based On Pascal Polynomials, Chih-Wen Chang, Jyh-Hong Wu, Ying-Ru Lin, Yu-Feng Lin, Nan-Nong Huang

Journal of Marine Science and Technology–Taiwan

Torsion bars are important elements in the marine structure applications. The usage of the composite torsion bars has increased recently because it takes advantage of the different material property of each constituent. The current research focuses mainly on the uniform warping analysis of composite torsion shafts by using the point collocation method (PCM). The PCM is based on Pascal's triangle polynomial expansion and coupled with subdomain technique that is indispensable for the analysis of composite bars. In addition to satisfying the field equation (Laplace equation for warping function) and traction-free boundary condition for each component, the continuity conditions in both …

Local Reinforcement Design And Safety Factor Evaluation Of Elliptical Hatch Of Pressure Hull, Guang-Min Luo, Jun-Wei Chen

Journal of Marine Science and Technology–Taiwan

A pressure hull is the primary pressure-resistant structure of a submarine. To safeguard the compressive strength of such a hull, local structural reinforcement is required for various hatches on the hull. Hatches are commonly reinforced through increasing the thickness of the hull regions around them; alternatively, hatch nozzle walls are connected with stiffened frames to maintain the continuity of reinforced structures. This study focused on a pressure hull with an elliptical hatch. A PD-5500 cylindrical pressure hull was used to design a cylindrical pressure hull structure, and a model of hatch nozzle reinforcement was designed using the Boiler and Pressure …

Effects Of Dietary Lipid, L-Carnitine And L-Lysine Supplementation On The Growth Performance And Body Composition Of Epinephelus Lanceolatus Larvae, Jen-Hong Chu, Yu-Cong Hong, Angela Chien, Shyn-Shin Sheen

Journal of Marine Science and Technology–Taiwan

The effects of different combinations of dietary lipid, L-carnitine and L-lysine on the growth performance and fatty acid profiles of larval grouper Epinephalus lanceolatus were evaluated. Eight treatment diets were formulated based on a 2x2x2 factorial design, namely 5 and 14% dietary oil mixture (3:1 fish oil/soybean oil), 0 and 0.5% L-carnitine and 0 and 2.83% L-lysine. Each diet was randomly assigned to triplicate groups of ten 0.08g E. lanceolatus larvae for 42 days. The grouper larvae fed with diets containing 14% lipid had significantly higher weight gain percentages than those fed with diets containing 5% lipid. The weight gain …

Evaluation Of Hydrodynamic Effects Of Waterway Restoration On An Estuarine Ecosystem, Megan Kramer

USF Tampa Graduate Theses and Dissertations

Estuaries are hydrodynamically complex for they are influenced by tidal forces, freshwater flows, salinity variations, and often intricate coastal land morphology. Furthermore, many estuaries are subject to constant anthropogenic stresses due to dense coastal populations, which are expected to be exacerbated by changing climate trends. The 1,800 home residential Manchester Waterway (MW) community located in Charlotte Harbor (along the Gulf of Mexico in Southwest Florida), is interested in improving boat access by restoring a previous connection between the local waterway and the harbor, separated by a barrier peninsula. The proposed connections aim to reduce boat traffic and travel time through …

Detecting The Feeding Habitat Zone Of Albacore Tuna (Thunnus Alalunga) In The Southern Indian Ocean Using Multisatellite Remote Sensing Data, Sandipan Mondal, Yang-Chi Lan, Ming-An Lee, Yi-Chen Wang, Bambang Semedi, Wan-Ya Su

Journal of Marine Science and Technology–Taiwan

Remote sensing is an effective method for identifying potential feeding habitat zones. Spatial and temporal distribution patterns of albacore (ALB) tuna were studied using Taiwan longline fisheries data from 2009 to 2014. A generalized additive model (GAM) was used to compile a fishery database and statistically explore the relationship between distribution and environmental factors. Sea surface temperature (SST), sea surface chlorophyll-a concentration (SSC), sea surface salinity (SSS), sea surface height (SSH), mixed layer depth (MLD), and eddy kinetic energy (EKE) were examined. The results indicated SST as the largest contributor on ALB distribution, followed by SSS and SSC. Catches per …

Japanese Consumer Preference For Raw Fish: Best–Worst Scaling Method, Takahiro Sajiki, Yu-Heng Lu

Journal of Marine Science and Technology–Taiwan

Given the declining consumption of fish and shellfish in Japan, it is essential to better understand consumer needs to design policies that increase consumption. Therefore, we clarify the relative degree of importance Japanese consumers place on various attributes of raw fish during purchase based on a questionnaire survey employing best–worst scaling. We find that consumers prioritize freshness, price, taste, appearance, safety, seasonality, ease of cooking and eating, nutrition, origin, wild fish, and effect on natural environment and ecosystem, in that order. Wild fish has unexpectedly low importance, although Japanese consumers conventionally purchase captured fishery products rather than cultured ones. The …

Diel Vertical Distribution Patterns Of Pelagic Fish Larvae In Yilan Bay, Taiwan, Yi-Chen Wang, Su-Chen Tsai, Wen-Yu Chen

Journal of Marine Science and Technology–Taiwan

To study the diel migration distribution of larval fish in an area adjacent to the Kuroshio Current, samples were collected from six depths by using a Motoda horizontal net at a fixed station in Yilan Bay on July 30 and 31, 2007. A total of 591 larval fish were collected and assigned to at least 34 families and 57 species. The first five dominant species were Benthosama pterotum (40.95%), Diaphus B type (12.18%), Callionymidae spp. (8.46%), Gobiidae spp. (6.60%), and Apogonidae spp. (4.0%). The density of larval fish varied across time. The maximum larval density was 1220.34 individuals/1000 m3 at …

Long-Term Variation Of Sea Surface Temperature In Relation To Sea Level Pressure And Surface Wind Speed In Southern Indian Ocean, Sandipan Mondal, Ming-An Lee, Yi-Chen Wang, Bambang Semedi

Journal of Marine Science and Technology–Taiwan

Sea surface temperature (SST) is an essential parameter associated with fish habitat and changes in oceanic conditions. Long-term SST variation in relation to sea level pressure (SLP) and surface wind speed (SWS) was observed based on the National Oceanic and Atmospheric Administration (NOAA) data of southern Indian Ocean. Mean monthly time series showed that February and November were the warmest and coolest months, respectively. Spatial distribution showed that 0°S–30°S was warm with SST of 20°–30°C, which was higher than that at all other places throughout the year. SLP (> 1010 millibar) and SWS (> 12 m/s) were high at 20°S–40°S …

Economic Conditions For New Entrants In Coastal Fishing In Miyazaki Prefecture, Japan, Takahiro Sajiki, Yu-Heng Lu, Norie Nishiguchi, Sonomi Akamine, Masaharu Nishiguchi

Journal of Marine Science and Technology–Taiwan

A significant decrease in the number of fishery workers is be-coming a problem in Japan. For new entrants to become estab-lished in the region, they must be profitable as fishing busi-nesses. Using the case of Miyazaki prefecture in Japan, this paper identifies the economic conditions required to make longline fishing and bottom gillnet fishing profitable by ap-plying the net present value (NPV) method. When operating on 200 days, which is the guideline for new entrants in longline fishing, if the value of investment is less than 44.1% of the minimum required, the investment will not provide positive returns. However, the …

Raw Garlic (Allium Sativum) Improves Nonspecific Immune Responses And Resistance Against Vibrio Alginolyticus Infection In Grouper (Epinephelus Coioides), Huai-Ting Huang, Po-Tsang Lee, Zhen-Hao Liao, Cheng-Ting Huang, Hsiang-Yin Chen, Zhi-Gu Huang, Fan-Hua Nan, Yu-Sheng Wu

Journal of Marine Science and Technology–Taiwan

Garlic contains various nutrients and healthful ingredients. The content of garlic products is closely related to their processing methods, and each compound has specific biological effects. Allicin, a heat labile compound, is considered the most important factor in garlic. Garlic powder is commonly prepared by subjecting raw garlic to thermal processing before being grounded into powder,and it is of interest to compare the biological activity of garlic powder with raw garlic in fish. This study investigated immune effects of raw garlic and garlic powder on groupers (Epinephelus coioides). Although raw garlic and garlic powder did not promote growth performance of …

Asymptotic Numerical Solutions For Second-Order Quasilinear Singularly Perturbed Problems, Chein-Shan Liu, Chih-Wen Chang

Journal of Marine Science and Technology–Taiwan

For a second-order quasilinear singularly perturbed problem under the Dirichlet boundary conditions, we propose a new asymptotic numerical method, which involves two problems: a reduced problem with a one-side boundary condition and a novel boundary layer correction problem with a two-sided boundary condition. Through the introduction of two new variables, both problems are transformed to a set of three first-order initial value problems with zero initial conditions. The Runge–Kutta method is then applied to integrate the differential equations and to determine two unknown terminal values of the new variables until they converge. The modified asymptotic numerical solution satisfies the Dirichlet …

Simulation Of A Ship And Tension Leg Platform Wind Turbine Collision, Jiamin Guo, Yu Zhao, Weigang Chen, Guangeng Zhou

Journal of Marine Science and Technology–Taiwan

Collisions between ships and tension leg platform wind turbines (TLPWTs) result in the TLPWT damage, including tower damage and tension leg breakage. This paper details a collision between a ship and TLPWT simulated using the LS-DYNA software package. During simulation, the behaviors of the water around the ship and of the TLPWT were processed using the constant added mass and the fluid–structure interaction methods, respectively. The results indicate that the energy conversion during collision is generally consistent with the law of conversion of energy, suggesting that the simulation’s calculations are acceptable. The TLPWT simulation results imply that two distinct collisions …

The Influences Of Promising Feedstock Variability On Advanced Biofuel Production: A Review, Cherng-Yuan Lin

Journal of Marine Science and Technology–Taiwan

The contribution of biofuels is expected to continuously increase in the global fuel market, as they are environmentally-friendly and provide renewable energy. Four generations of biofuels are categorized and are primarily based on their feedstock sources and the production technologies that are used. The influence of promising feedstock types and the availability on the production technologies and the fuel properties of advanced-generation biofuels are not systematically examined in the literature. Hence, this research extensively reviews the potential impact of feedstock sources and their variability on the production and characteristics of biofuels. The approaches of theoretical analysis and inference referred to …

Passivity-Based Numerical Modeling And Grid Integration Strategies For Wave Energy Converter Arrays, Salman Husain

Dissertations, Master's Theses and Master's Reports

The body of work presented here develops numerical time-domain models of Wave Energy Converter (WEC) arrays or wave farms. It will be shown here that a cluster of WECs can be more effective in extracting oceanic energy, can facilitate deployment logistics, and help with grid integration. The objectives of this work are: (i) developing a theoretical metric to evaluate the energy extraction potential of a WEC array, (ii) developing an algorithm that ensures the stability of the time-domain models of WEC arrays, and (iii) identifying strategies that facilitate grid integration and power management of a WEC array. In the process …

Optimal Control Of Nonlinear Wave Energy Converters In Heave For Maximum Power Extraction, Kevin Nelson

Dissertations, Master's Theses and Master's Reports

The marine renewable energy community is interested in maximizing the power generated by nonlinear wave energy converters. Optimal control methods provide a tool to achieve this aim and can also help to inform the buoy design. An energy-optimal control law for a class of non-linear buoy models is derived and is shown to be singular. The solution approach is illustrated using an hourglass-shaped buoy having a cubic, hydrostatic nonlinearity. The optimal control law is only valid on singular arcs, and a method to search for these arcs is presented. Two singular arcs are found for the hourglass buoy model and …

Development And Validation Of A Force Measuring Device For A Laboratory Wave Tank, Jacob K. Colling

Dissertations, Master's Theses and Master's Reports

The ability to predict the hydrodynamic force exerted on floating bodies plays a critical role in creating more effective control strategies for wave energy converters (WECs). Developing a test apparatus capable of directly measuring the forces exerted on a floating body subjected to a wavefield provides the means to validate theoretical prediction methods with experimental results and to develop data-based prediction methods for hydrodynamic forces. This report will discuss the development and validation of a device that measures the total vertical force exerted on a test artifact. The device requirements and design are discussed to examine the factors taken into …

Coastal Wave Powered Reverse Osmosis System, Alexander Raymond Charest, Joeseph Daniel Camobreco, Tori Sweet, Sam Williams, Andrew Lepage, Devan Sack, Meagan Wiggin, Chelsea Kimball, Brendan Reagan

Honors Theses and Capstones

Part of the Marine Energy Collegiate Competition (MECC) is the optional Build and Test Challenge where teams are encouraged to build a portion of their proposed solution. After the conducted testing the laboratory results are compared to the simulated and calculated models. For the MECC the University of New Hampshire (UNH) team decided to use a wave energy converter to produce pressurized water. The pressurized water would be filtered through a reverse osmosis membrane to make it potable. Our system uses the power of the ocean waves to move a float up and down in heave motion. This motion drives …