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Mechanical Engineering

Journal

2022

Articles 121 - 131 of 131

Full-Text Articles in Physical Sciences and Mathematics

Local Reinforcement Design And Safety Factor Evaluation Of Elliptical Hatch Of Pressure Hull, Guang-Min Luo, Jun-Wei Chen Mar 2022

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

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 …

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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 Mar 2022

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

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 …

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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 Jan 2022

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

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 …

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Japanese Consumer Preference For Raw Fish: Best–Worst Scaling Method, Takahiro Sajiki, Yu-Heng Lu Jan 2022

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

Journal of Marine Science and Technology

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 …

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Diel Vertical Distribution Patterns Of Pelagic Fish Larvae In Yilan Bay, Taiwan, Yi-Chen Wang, Su-Chen Tsai, Wen-Yu Chen Jan 2022

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

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 …

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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 Jan 2022

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

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 …

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Economic Conditions For New Entrants In Coastal Fishing In Miyazaki Prefecture, Japan, Takahiro Sajiki, Yu-Heng Lu, Norie Nishiguchi, Sonomi Akamine, Masaharu Nishiguchi Jan 2022

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

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 …

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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 Jan 2022

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

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 …

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Asymptotic Numerical Solutions For Second-Order Quasilinear Singularly Perturbed Problems, Chein-Shan Liu, Chih-Wen Chang Jan 2022

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

Journal of Marine Science and Technology

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 …

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Simulation Of A Ship And Tension Leg Platform Wind Turbine Collision, Jiamin Guo, Yu Zhao, Weigang Chen, Guangeng Zhou Jan 2022

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

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 …

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The Influences Of Promising Feedstock Variability On Advanced Biofuel Production: A Review, Cherng-Yuan Lin Jan 2022

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

Journal of Marine Science and Technology

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 …

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