• Nutritional Sciences
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• v.8 no.3
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• pp.175-180
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• 2005

Green tea, which has high polyphenols amount, is thought to have hypocholesterolemic effects. The present study was performed to further examine the hypocholesterolemic action of green tea, especially (-) epigallocatechin gallate (EGCG) for its effect on diet-induced hypercholesterolemia in rats. Male Sprague-Dawley rats (n=15) were fed a green tea-free diet (control), $1.0\%$ green tea catechin (catechin) or $0.5\%$ green tea catechin EGCG for seven weeks. Hypercholesterolemia was induced by adding $1\%$ cholesterol and $0.5\%$ cholic acid to all diets. There was no difference in food intake and body weight gain among the groups. The green tea EGCG treatment led to a significant improvement in plasma levels of total cholesterol, low density lipoprotein (LDL)-cholesterol and high density lipoprotein (HDL)/LDL ratio (p<0.05). There was no significant effect on the plasma HDL-cholesterol level. The catechin treatment led to a 4.19-fold increase in the LDL-receptor mRNA level compared to the control, but the EGCG treatment did not affect the hepatic LDL-receptor mRNA level. Our results suggest that when blood cholesterol level is down-regulated by green tea EGCG, the LDL receptor gene-independent pathway may dominate the hypocholesterolemic action of EGCG.

• Microbiology and Biotechnology Letters
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• v.43 no.4
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• pp.350-356
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• 2015

There have been several studies on role of hormesis with light stimulation, however, the influence of light on fermentation is still poorly understood. In this study the relationship between LED (light emitting diode) hormesis and ethanol fermentation for Muscat bailey A wine was investigated. Two LEDs, one blue ($453{\pm}4nm$) and one green ($522{\pm}3nm$), were used. Both LED groups showed an inhibited production of lactic acid. The blue LED stimulated the growth of the yeast in early stage of the fermentation. Polyphenolic compounds and their antioxidant abilities were significantly increased by the green LED. These results demonstrate that LED irradiation must bring about hormesis and affect the growth rate of yeast in the early stage of the fermentation, and the contents of phytochemicals during fermentation. These findings indicate the possible application of LED hormesis for the wine fermentation. Further studies are needed to understand how LED irradiation induces hormesis effects during the fermentation process.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.442-448
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• 2012

This study investigated reduction of microbial population, water soluble pigment, capsanthin content, surface color (Hunter L, a, b, ${\Delta}E$), and sensory properties of pepper powder by LED (red, yellow, blue, green) treatments. LED (red, yellow, blue, green) treatment were conducted in 1,000 lux storage at $25^{\circ}C$ for 10 days. The total aerobic bacteria was no significant difference among the control and treated with LED during 10 days. In yellow LED treatment, yeast and molds were decreased about 1.76 log. Surface color such as lightness (L), redness (a), yellowness (b) were showed a decreasing tendency as the storage period. In the overall color difference (${\Delta}E$) of yellow LED treatment was lower less than 3.0. Water soluble pigment was no difference in control and LED treated samples during storage period. Capsanthin content was significantly decreased as storage period was increased, but no significant differences were observed among red and yellow LED treatments. Sensory properties of control was significantly reduced by storage period but yellow and green LED treatments were no significantly differences.

• Journal of Mushroom
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• v.12 no.4
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• pp.375-378
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• 2014

The attractions of Lycoriella ingenua to different LED light sources were investigated in the mushroom cultivations which were located in Yongin of Gyeonggi-do province and Buyeo of Chungcheongnam-do Province. The LED light sources which were used in the investigations were white, green, red, blue and orange. Numbers of Lycoriella ingenua to LED lights in Yongin and Buyeo were 132.9 and 3,272.5 to white LED source, 120.3 and 3,109.5 to green LED source, 105.5 and 1,910.1 to red LED source, 88.3 and 2,708.3 to blue LED source and 46.7 and 2,465.5 to orange LED source, respectively. The numbers of Lycoriella ingenua to LED light sources were 2.7~3.5 times higher than the ones of untreated.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.179-187
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• 2015

Experiments designed to measure the effect of LED (light-emitting diode) light wavelength on the growth of fingerling rockfishes (Sebastes inermis) were conducted. Fingerling rockfishes (average body weight of individual: 1.13g) were divided into two groups by wavelength of the LED light [light power: 1,620 mW; wavelength: 518 nm (green color), 622 nm (red color)]. Triplicate groups of 180 individuals were reared over 7 weeks. Lighting duration was 14 hours from 06:00 to 20:00. A water tank exposed on the natural light in a room through the windows was used as a control. At results of the first experiment [initial average body weight (BW) of individual: 1.13 g; standard deviation (SD): 0.13 g], the final individual BW exposed on the green color was increased 0.39 g than the red color, and decreased 0.12 g than the natural light in the room. At results of the second (initial individual BW: 5.07 g; SD: 0.70 g) and the third experiment (initial individual BW: 10.67 g; SD: 0.67 g), the final individual BW exposed on the green color was increased 1.07 g and 2.55 g than the red color, respectively, and increased 0.57 g and 0.84 g than the natural light, respectively. The relative growth rate of the green color was higher about 8% significantly (p<0.05) than the natural light. In the case of the red color the relative growth rate was lower significantly (p<0.05) than the natural light.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.26-32
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• 2011

In this study, a standard illuminant A type LED that has similar emission spectrum as the standard illuminant A was developed using LED chip(emission peak: 405[nm]) and four types of phosphors(blue, green orangered and red). Using the design of experiment for spectrum control, the trend of the change of spectrum shape influenced by the change of interaction among phosphors and their density could be examined. Computer simulation through the optimization of the design of experiment revealed that, among four phosphors, the most influential one on the shape of the spectrum was green phosphor. Using the obtained optimal combination ratio of the four phosphors, an alternative LED illuminant to the actual standard illuminant A was developed and the spectrums of these two were confirmed identical. Using this standard illuminant A type LED, a portable transmittance meter with the range of measurement error of ${\pm}1.0$[%] was developed.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.2
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• pp.174-184
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• 2013

For the successful R&D and deployment of LED-based green energy lighting systems, the real-time power quality measurement of both various non-linear power signals including pulse waveform, spike waveform, etc and the undesired-signals including harmonics, sag, swell, etc is required. In this paper, we propose a low-cost power quality measurement (PQM) method for low- (60Hz-several KHz) to high-frequency (several tens KHz) power signals, which are generated by green-energy lighting systems, and implement a PQM testbed using TI TMS320F28335 MCU. The proposed algorithm is programmed using C in the CCS (Code Composer Studio) 3.3 environment and is verified using test signals generated by an arbitrary signal generator, NF-WF1974. In the implemented testbed, we can measure various non-linear current signals that LED SMPS generates, analyze harmonics by fast Fourier transform, and test sag, swell, and interruption using wavelet transform.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1219-1225
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• 2003

According to the increase of lifetime and efficiency, the interest in the pLED has dramatically increased recently because pLED can be applied to large-size and flexible displays. The core process in the manufacture of pLED is the printing process of red, green and blue light emitting polymers (LEP), and inkjet printing method is one of the promising technology to print red, green and blue LEP on glass substrates. In this work, we developed a multi-head inkjet patterning system with 3 heads for each color. The developed inkjet patterning system is composed of the precise positioning system, head controller circuit, real-time ink drop evaluation system, maintenance system, and stable ink supply system. Finally, we investigated the stability and reliability of the system by printing red, green and blue LEP on the dummy substrate.

• Journal of the Korean Chemical Society
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• v.50 no.2
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• pp.137-140
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• 2006

In this report, Europium doped strontium barium gallium silicate ((Sr,Ba)2Ga2SiO7:Eu2+) phosphor has been synthesized by conventional solid-state method and investigated luminescent characteristic. Appropriate proportions of the raw materials were mixed in an agate mortar with acetone to obtain starting mixtures. Also, this phosphor was prepared by simple process under the reduction atmosphere (25% H2/75% N2). This phosphor can be applicated to the green phosphor for white LED because it has green emission band (513 nm), which emits efficiently under the 405nm excitation energy.

• Transactions on Electrical and Electronic Materials
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• v.15 no.2
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• pp.66-68
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• 2014

Most commercial white LED lamps use blue chip coated with yellow emitting phosphor. The use of blue excitable red and green phosphors is expected to improve the CRI. Several phosphors, such as $SrGa_2S_4:Eu^{2+}$ and $(Sr,Ba)SiO_4:Eu^{2+}$, have been suggested in the past as green components. However, there are issues of the sensitivity and stability of such phosphors. Here, we describe gallium substituted $YAG:Ce^{3+}$ phosphor, as a green emitter. YAG structures are already accepted by the industry, for their stability and efficiency. LEDs with improved CRI could be fabricated by choosing $Y_3Al_4GaO_{12}:Ce^{3+}$ (green and yellow), and $SrS:Eu^{2+}$ (red) phosphors, along with blue chip. Also, the effect of a slight change in chip wavelength is studied, for two phosphor-coated w-LEDs. The reduction in particle size of the coated phosphors also gives improved w-LED characteristics.