• Journal of Power System Engineering
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• v.19 no.2
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• pp.90-95
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• 2015

Recently worldwide concern and research is being actively conducted on green energy which can reduce environmental pollution. A plant such as the natural rapeseed oil, soybean oil, palm, etc. is used as a bio source in home and industry. Biofuels is a sustainable fuel having economically benefits and decreasing environmental pollution problems caused due to fossil fuel, and it can be applied to the conventional diesel engine without changing the existing institutional structure. Waste vegetable oil contains a high cetane number and viscosity component, the low carbon and oxygen content. A lot of research is progressing about the conversion of waste vegetable oil as renewable clean energy. In this study, waste oil was prepared to waste cooking oil generated from the living environment, and applied to diesel engine to confirm the possibility and cost-effectiveness of biodiesel blend waste oil. As a result, brake specific fuel consumption and NOx was increased, carbon monoxide and soot was decreased.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.3
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• pp.203-210
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• 2016

In this study, nine heavy metals were analyzed in seaweeds collected from market and laver culture farm of Korea and a food safety assessment were also carried out for these heavy metals. The level of heavy metal concentrations in seaweeds was in the following order: Fe>As>Zn>Cu>Cd>Pb>Cr>Ni>Hg. Except for zinc and cadmium, seven heavy metals were significantly higher in cultured laver than in processed laver. Significant correlation was observed Cr-Fe in cultured laver and Cu-Zn, Cd-Cu, Cd-Zn and Pb-Ni in processed laver and Cu-Cr, Cu-Zn, Cd-Cr and Ni-Fe in sea tangle and Zn-Fe, Cr-Fe, Cr-Zn, Cd-Ni, Cu-Cd and Cu-Pb in processed sea mustard. Considering differences in heavy metal concentration between processed laver and cultured laver and in correlation among heavy metals, removal efficiency of heavy metals may be attributed to seaweed treatment process. The average weekly intakes of Cu, Cd, Zn, Fe and Hg via seaweeds consumption were about 0.1~7.6% of PTWI (Provisional Tolerable Weekly Intakes). Therefore, it was found that heavy metals in the seaweeds were very safe for consumption.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.314-319
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• 2010

This study determined the proper inclusion levels of squid liver powder (SLP) - soy protein concentrate (SPC) premix as a fish meal (FM) substitute in the diet for juvenile olive flounder (Paralichthys olivaceus). All the experimental diets were formulated to be isonitrogenous (50% crude protein) and isocaloric (17.1 kJ energy $g^{-1}$ diet). Five diets were formulated with SLP-(SPC) replacing 0, 25, 50, 75, and 100% of the FM (SLP $(SPC)_0$, SLP $(SPC)_25$, SLP $(SPC)_50$, SLP $(SPC)_75$, and SLP $(SPC)_100$, respectively). Triplicate groups of 12 fish averaging $5.56{\pm}0.10\;g$ ($mean{\pm}SD$) were fed one of the five experimental diets for 7 weeks. The weight gain (WG), specific growth rate (SGR), feed efficiency (FE), and protein efficiency ratio (PER) of fish fed SLP $(SPC)_0$ were significantly (P<0.05) higher than those of fish fed SLP $(SPC)_50$, SLP $(SPC)_75$ and SLP $(SPC)_100$, while those of fish fed SLP $(SPC)_0$ and SLP $(SPC)_25$ were similar. The whole-body crude protein content of fish fed SLP $(SPC)_0$ was significantly (P<0.05) lower than that of fish fed SLP $(SPC)_50$, SLP $(SPC)_75$, and SLP$(SPC)_100$, while those of fish fed SLP $(SPC)_0$ and SLP $(SPC)_25$ were similar. The whole-body crude lipid of fish fed SLP $(SPC)_0$ was significantly (P<0.05) lower than that of fish fed SLP $(SPC)_50$ and SLP $(SPC)_75$, while those of fish fed SLP $(SPC)_0$, SLP $(SPC)_25$ and SLP $(SPC)_100$ were similar. Based on the fish growth performance results obtained from this study, the SLP (SPC) premix can substitute up to 25% of the FM in the diets of juvenile olive flounder.

• Preventive Nutrition and Food Science
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• v.20 no.2
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• pp.133-136
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• 2015

Freshwater softshell turtle (Trionyx sinensis) extract has been used traditionally as a tonic soup, and to recover from physical fatigue. To support these claims, the forelimb grip strength of mice was measured after feeding a soft-shell turtle extract for 7 days. The T. sinensis extract significantly increased the grip strength to $1.25{\pm}0.07N$ (P<0.01), which is 16.8% higher than the force on day 0. After exercising, the blood glucose levels in extract-fed mice were 202% higher and urea levels were 73% lower, which were both significantly different than the levels observed after control treatment. Lactate dehydrogenase was significantly higher by 314%, and glutathione peroxidase increased by 165%. In addition, the obesity markers, serum triglyceride and cholesterol, decreased to 62% and 49%, respectively, after mice were fed the extract. These data show that the T. sinensis extract provided more energy for forelimb exercise, prevented protein catabolism and muscle fatigue, and decreased the oxidative stress caused by an exhaustive workout.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.37-46
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• 2016

This study describes the spatio-temporal distributions in phytoplankton community such as species composition, standing crops and dominant species from April to November 2008 in the Uljin Marine Ranching Area (UMRA). A total of 123 species of phytoplankton belonging to 67 genera was identified. In particular, diatoms and dinoflagellates were occupied more than 60.5% and 34.6% of total species, respectively. The annual dominant species were Thalassiosira sp., Pseudo-nitzschia pungens in spring, Leptocylindrus danicus, Guinardia striata in early summer, Cheatoceros cirvisetus, Ch. decipiens in early autumn and Skeletonema costatum -ls (like species), Pn. pungens in autumn. Phytoplankton cell density fluctuated with an annual mean of $48cells{\cdot}mL^{-1}$ between the lowest value of $1.8cells{\cdot}mL^{-1}$ in early autumn and the highest value of $240cells{\cdot}mL^{-1}$ in spring. According to the cluster analysis, the phytoplankton community of the UMRA was characterized by the nutrient supply from land side and water movement as current.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.1
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• pp.38-46
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• 2012

This study carried out current status, characteristics, and problems of coastal environment management on semi-enclosed Masan Bay in Korea and suggests cost-effective and eco-friendly water quality management policy. The pollutants from terrestrial sources into the Bay have apparently environmental pollution problems, such as eutrophication, red tide, and hypoxia. The carrying capacity of the Bay is estimated by hydrodynamic model and ecosystem model, material circulation including bivalve in ecosystem is analyzed by the growth model of bivalve. The resulting reduction in the input load was found to be 50~90%, which is unrealistic. When the efficiency of water quality improvement through bivalve farming was assessed based on the autochthonous COD, 30.7% of the total COD was allochthonous COD and 69.3% was autochthonous COD. The overall autochthonous COD reduction rate by bivalve aquaculture farm was found to be about 6.7%. This study indicate that bivalve farming is about 31% less expensive than advanced treatment facilities that remove both nitrogen and phosphorous.

• BMB Reports
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• v.46 no.12
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• pp.575-581
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• 2013

Lipid droplet (LD) is a cellular organelle that stores neutral lipids as a source of energy and carbon. However, recent research has emerged that the organelle is involved in lipid synthesis, transportation, and metabolism, as well as mediating cellular protein storage and degradation. With the exception of multi-cellular organisms, some unicellular microorganisms have been observed to contain LDs. The organelle has been isolated and characterized from numerous organisms. Triacylglycerol (TAG) accumulation in LDs can be in excess of 50% of the dry weight in some microorganisms, and a maximum of 87% in some instances. These microorganisms include eukaryotes such as yeast and green algae as well as prokaryotes such as bacteria. Some organisms obtain carbon from $CO_2$ via photosynthesis, while the majority utilizes carbon from various types of biomass. Therefore, high TAG content generated by utilizing waste or cheap biomass, coupled with an efficient conversion rate, present these organisms as bio-tech 'factories' to produce biodiesel. This review summarizes LD research in these organisms and provides useful information for further LD biological research and microorganism biodiesel development.

• Journal of Advanced Research in Ocean Engineering
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• v.2 no.4
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• pp.169-178
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• 2016

Recently, artificial reefs (ARs) have been frequently used primarily owing to the development in AR materials and projects for relatively complicated, large ARs. Among several engineering issues of ARs, wake region of an AR has been characterized because these regions have a high probability of recruiting seaweed spores, providing an energy saving zone, and facilitating deposition of sediments, nutrients, and bio-deposits. To characterize an efficiency index of an AR wake region and its dependency on the prevailing water flow directions, this study proposes a so-called efficiency index diagram. This characterization is done by normalizing the wake volumes with respect to the real AR volume and illustrating how efficiency indices vary with respect to the inlet flow directions. As a result, according to the diagram characteristics such as an averaged efficiency index, fundamental symmetric angle, secure angles, and principal directions, we can easily figure out how a target AR should be aligned along the main water flows to maximize the wake region around the AR. In addition, six ARs are considered and their efficiency index diagrams are illustrated to pinpoint the physical characteristics.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.400-407
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• 2016

A unicellular green alga, Chlorella vulgaris KNUA027, was isolated from the roots of Panax ginseng seedlings and its biotechnological potential was investigated. The results of GC/MS analysis showed that C. vulgaris KNUA027 was rich in nutritionally important polyunsaturated fatty acids (PUFAs) such as alpha-linolenic acid (C_18:3 ω3, 45.8%, 50.8 mg/g) and hexadecatrienoic acid (C_16:3 ω3, 11.8%, 13.1 mg/g). Therefore, this Korean indigenous microalga may have potential as a source of omega-3 PUFAs. It was also found that the saturated palmitic acid (C_16:0, 37.1%, 41.2 mg/g), which is suitable for biodiesel production, was one of the major fatty acids produced by strain KNUA027. The proximate analysis showed that the volatile matter content was 88.5%, and the ultimate analysis indicated that the higher heating value was 19.8 MJ/kg. Therefore, the results from this research with C. vulgaris KNUA027 may provide the basis for the production of microalgae-based biofuels and biomass feedstock.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.82-87
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• 2013

Effects of material surface property, hydrophobic or hydrophilic, on the bio-fouling occurred on the bodies submerged in the sea water are investigated experimentally. 4 test models are used in the experiment, which includes aluminum foil in common use, AAO applied hydrophobic surface, HDFS coated hydrophobic surface and hydrophilic surface. Hydrophobic surfaces with numerous micro & nano-scale pillars on it seems to play very important role of preventing them from fouling in initial stage while the effects disappear in long term sense of fouling process. It is concluded that the surface hydrophobicity retards the initial fouling until the fouling thickness is smaller than the heights of the pillars on it but the effects diminish with the fouling proceeds so that the thickness grows bigger than the pillar heights.