• Preventive Nutrition and Food Science
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• v.9 no.1
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• pp.58-64
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• 2004

This study investigated the effects of carnitine and/or ${\gamma}$ -aminobutyric acid (GABA) supplementation on lipid profiles and some immune related nutrient in mice. Balb/c male mice were orally treated with either an AIN-76 diet (Con), a control diet plus carnitine (CS, 0.5 g/kg bw), a control diet plus GABA (GS, 0.5 g/kg bw) or a control diet plus carnitine plus GABA (CGS, 0.25 g/kg bw, respectively) for 6 weeks. There were no significant differences in feed consumption, energy intake, body weight gain or feed efficiency ratio among the groups during the experimental period. However, abdominal fat deposits were smaller in CS, GS and CGS groups compared with the Con group. Serum and liver triglycerides also were lower in CS, GS and CGS and serum total cholesterol was significantly lower in the CGS group compared with the Con group. Serum LDL cholesterol was lower in the CGS group and liver HDL cholesterol was significantly higher in the CS group compared with Con group. In serum, stearic acid and selecholeic acid were lower, but arachidic acid was higher in the CS group. Liver stearic acid was higher but oleic acid lower in CGS group compared with Con group. In carnitine supplemented groups, serum and liver nonesterified carnitine (NEC), acidsoluble acylcarnitine (ASAC), total carnitine (TCNE) concentrations were higher in only the CS group, not CGS group. Serum vitamin A and E concentrations were not different among the groups. These results may suggest that carnitine and/or GABA supplementation improves lipid profiles in mice, but did not affect the immune-related nutrients that we measured under the experimental conditions of this study.

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.226-231
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• 2006

Several white-rot fungi are able to produce extracellular lignin-degrading enzymes such as manganese peroxidase (MnP), lignin peroxidase (LiP), and laccase. In order to enhance the production of laccase and MnP using Trametes versicolor KCTC 16781 in suspension culture, the effects of major medium ingredients, such as carbon and nitrogen sources, on the production of the enzymes were investigated. The decolorization mechanism in terms of biodegradation and biosorption was also investigated. Among the carbon sources used, glucose showed the highest potential for the production of laccase and MnP. Ammonium tartrate was a good nitrogen source for the enzyme production. No significant difference in the laccase production was observed, when glucose concentration was varied between 5 g/l and 30 g/l. As the concentration of nitrogen source increased, a lower MnP activity was observed. The optimal C/N ratio was 25 for the production of laccase and MnP. When the concentrations of glucose and ammonium tartrate were simultaneously increased, the laccase and MnP activities increased dramatically. The maximum laccase and MnP activities were 33.7 U/ml at 72 h and 475 U/ml at 96 h, respectively, in the optimal condition. In this condition, over 90% decolorization efficiency was observed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.2
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• pp.157-166
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• 1985

The Purpose of this study are to investigate the characteristics of the flame behavior of gasoline-methanol blended fuels in spark ignition engine. Ionization probe were installed at the cylinder head and piston in order to measure flame speed. Other parameter such as engine performance, fuel consumption rate and exhaust gas were measured. The results were as follows. 1. In the case of increase methanol contents in blend fuel, flame propagation speed were increased, and thermal efficiency of the engine were increased due to decrease of energy consumption rate. 2. In the case of fixed equivalance ratio, NO sub(X) in exhaust gas were increased in accordance with increase of spark advance, and mean effective pressure were decreased in accordance with increase of methanol contents. 3. CO and HC concentration were decreased in accordance with increase of methanol contents.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.2
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• pp.162-168
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• 2002

The purpose of this study is to research and develop LiMnO$_2$-organic and Li$_{0.3}$MnO$_{2}$-organic composite with high energy density for Lithium ion polymer battery. This paper describes cyclic voltammetry, impedance sepctroscopy, electrochemical properties of LiMnO$_2$-organic and Li$_{0.3}$MnO$_{2}$-organic composite with polymer electrolyte as a function of a mixed ratio. The first discharge capacity of LiMnO$_2$-PAn with 3 wt.% PAn was 83mHA/g, while that of Li$_{0.3}$MnO$_{2}$-PPy composite was 136 mAh/g. The Ah efficiency was above 98% after the 2nd cycle. The LiMnO$_2$-PAn with DMcT 2 wt.% and Li$_{0.3}$MnO$_{2}$-PPy composites cathode with 5wt. PPy in PVDF-PC-EC-LiClO$_4$ electrolyte showed good capaity with cycling. The discharge capacity of LiMnO$_2$-PAn with wt.% DMcT was 80 and 130 mAh/g at 1st and 12th cycle, respectively. The capacity of LiMnO$_2$-PAn composite with 2 wt.% DMcT was higher than that of LiMnO$_2$-PAn composite.mposite.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.239-245
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• 2007

The effect of ultraviolet-B (UV-B) radiation on photosynthesis was studied by the simultaneous measurements of $O_2$ evolution and chlorophyll (Chl) fluorescence in tobacco leaves. When the tobacco leaves were teated with UV-B (1 $W{\cdot}m^{-2}$), the maximal photosynthetic $O_2$, evolution (Pmax; 4.60 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) at 200 ${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) was decreased with increasing time of UV-B treatment showing 80% decline after 4 h treatment. Chl fluorescence parameters were also affected by ultraviolet-B. Fo was increased while both Fm and Fv were decreased, resulted in the decreased of photochemical efficiency of PSII (Fv/Fm). Non-radiative dissipation of absorbed light as heat as estimated as NPQ (Fm/Fm' - 1) was also decreased with increasing time of UV-B treatment while the extent of photochemical quenching (qP) was not changed. Thus, the ratio of (1-qP)/NPQ parameter was also increased with increasing time of UV-B treatment indicating PSII is under the threat of photoinhibition. The result indicate that UV-B primarily decreases the capacity to dissipate excitation energy by trans-thylakoid pH, which in turn inhibits PSII activity.

• Journal of Aquaculture
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• v.10 no.1
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• pp.77-85
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• 1997

A 6-week feeding trial was conducted to determine the nutritional value of various dietary animal protein sources in juvenile Koran rockfish. White fish meal (WFM), flounder muscle meal (FMM), blood meal (BM), casein & gelain (CG), egg white albumin (EWA) and squid liver powder (SLP) were used as the animal protein sources, Crude protein content and available energy of the experimental diets were 50% and 15.9 kJ/g, respectively. There were significant differences among all dietary groups in weight gain (WG), feed efficiency (FE), and protein effiency ratio (PER). WFM and FFM were the best animal protein sources among the dietary groups. FMM diet had significantly higher (P<0.05) WG, FE, and PER values than those of fish fed the WFM diet. WG, FE, PER, and specific growth rate (SGR) values of fish fed BM diet were significantly higher (P<0.05) than those of fish fed EWA diet. Significant differences were found in whole body composition, hemoglobin (Hb), hepatosomatic index (HSI), and hematocrit (Ht). These results showed that low-temperature processing of lyophilized flounder muscle meal resulted in superior performance of rockfish relative to the other evaluated animal protein sources.

• Preventive Nutrition and Food Science
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• v.8 no.2
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• pp.137-140
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• 2003

Anti-obesity effect of a new dietary supplement (3D-relax) in high-fat fed rats. The aim of this study was to assess the effects of 3D-relax; a proprietary formulation containing hydroxycitrate (233 mg/g), carnitine (150 mg/g) and red pepper (150 mg/g); on body weight, body fat, and serum lipids levels in rats fed a high-fat diet. Male SD 7-wk-old rats (n=8) were fed a high fat diet [52% total dietary energy (E%) from fat, 15.4 E% protein, 32.6E% carbohydrate] with or without 3D-relax administration (1 g/kg body weight/day) for 3 weeks. Administration of 3D-relax significantly reduced the increase in body weight compared to the group fed high fat without 3D-relax. Food efficiency ratio (FER) tended to be decreased with administration of 3D-relax, but was not significant. The perirenal and epididymal fat pad weights of vats administered 3D-relax were significantly lower than those of the high fat group that did not ingest 3D-relax during the 3 weeks. The oral administration of 3D-relax significantly increased HDL-cholesterol level and lowered total cholesterol level compared to those of high fat alone group. These results suggest that 3D-relax reduced body weight and fat gains, and those effects are presumably linked to its inhibitory effects on lipogenesis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.6
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• pp.798-802
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• 2013

In a conventional DC power supply used for CO2 laser, the circuit elements such as a rectifier bridge, a current-limiting resistor, a high voltage switch, energy storage capacitors ans a high-voltage isolation transformer using high turn ratio are necessary. Consequently, those supplies are expensive and require a large space. Thus, laser resonator and power supply should be optimally designed. In this paper, we propose a new power supply using high frequency resonance phenomena for CW(Continuous wave) CO2 laser (maximum output of 23W with discharge length of 450mm). It consists of a transformer including leakage inductance, magnetizing inductance and half-bridge converter, a three-stage Cockcroft-Walton and PFC(Power factor correction) circuit. The output ripple voltage can be controlled the minimum of 0.24% under the high frequency switching of 231kHz. Furthermore, the output efficiency was improved to 16.4% and the laser output stability of about 5.6% was obtained in this laser system.

• Resources Recycling
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• v.16 no.6
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• pp.28-33
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• 2007

Coal is the most abundant energy source and deposited in every area of world. Combustion process with lower efficiency has been mainly used. Therefore, implementation of more efficient technologies, involving gasification, combined cycles and fuel cells, would be a key issue in the plans for more efficient power generation. In these technologies, gasification has been studied for decades. However, coal gasification to high value combustible gas such as hydrogen and carbon monoxide is focused again due to high oil price. The gaseous product, called syngas, can be effectively utilized in a variety of ways ranging from electricity production to chemical industry (as feedstock). In this study, coal gasification with ultra high temperature steam has been performed. The effect of steam/carbon ratio on the produced gas concentrations, gasification rate and additional products like tar, ammonia and cyan compounds has been determined.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.9
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• pp.755-759
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• 2011

$Cu(In_{1-x},Ga_x)Se_2$ thin films have been considered as an effective absorber material for high efficient solar cells. In this paper, the CIGS thin films with varied Ga content were prepared using a co-evaporation process of three stage. We carry out structure and electrical optical property on the thin film in varied Ga content. CIGS thin films have been characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS), four-point probe measurement, and the Hall measurement. To optimize Ga contents, Ga/(In+Ga) ratio were changed from 0.13 to 0.72. At this time the carrier concentrations were varied from $1.22{\times}10^{11}\;cm^{-3}$ to $5.07{\times}10^{16}\;cm^{-3}$, and electrical resistivity were varied from $1.11{\times}10^0\;{\Omega}-cm$ to $1.08{\times}10^2\;{\Omega}-cm$. A strong <220/204> orientation and a lager grain size were obtained at a Ga/(In+Ga) of 0.3. We were able to achieve conversion efficiency as high as 15.95% with a Ga/(In+Ga) of 0.3.