• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1093-1095
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• 2003

The mixed gas of Hydrogen and Oxygen has obtained from water electrolysis reaction. It has constant volume ratio 2 : 1 Hydrogen and Oxygen, and it is used as a source of thermal energy by combustion reaction. In this paper, Brown Gas Generator with Instantaneous source power control method is designed and relationship between brown gas quantities, efficiency and power condition is studied.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.22 no.4
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• pp.217-239
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• 2018

This paper examined the MHD and thermal behavior of unsteady mixed convection flow of a rotating fluid in a porous parallel plate channel in the presence of Hall current and heat source. The exact solutions of the concentration, energy and momentum equations are obtained. The influence of each governing parameter on non dimensional velocity, temperature, concentration, skin friction coefficient, rate of heat transfer and rate of mass transfer at the porous parallel plate channel surfaces is discussed. During the course of numerical computation, it is observed that as Hall current parameter and Soret number at the porous channel surfaces increases, the primary and secondary velocity profiles are increases while the primary and secondary skin friction coefficients are increases at the cold wall and decreases at the heated wall. In particular, it is noticed that a reverse trend in case of heat source parameter.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.1
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• pp.11-14
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• 2012

The AlGaN layer has direct wide bandgaps ranging from 3.4 to 6.2 eV. Nowadays, it is becoming more important to fabricate optical devices in an UV region for the many applications. The high quality AlGaN layer is necessary to establish the UV optical devices. However, the growth of AlGaN layer on GaN layer is difficult due to the lattice mismatch and difference thermal expansion coefficient between GaN layer and AlGaN layer. In this paper, we attempted to grow the LED structure on GaN template by mixed-source HVPE method with multi-sliding boat system. We tried to find the optical and lattice transition of active layer by control the Al content in mixed-source. For the growth of epi layer, the HCl and $NH_3$ gas were flowed over the mixed-source and the carrier gas was $N_2$. The temperature of source zone and growth zone was stabled at 900 and $1090^{\circ}C$, respectively. After the growth, we performed the x-ray diffraction (XRD) and electro luminescence (EL) measurement.

• Journal of Animal Science and Technology
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• v.62 no.5
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• pp.638-647
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• 2020

This study determined the substitution effects of rice for corn as the main grain source in a total mixed ration (TMR). In vitro rumen fermentation characteristics and microbes were assessed using two experimental diets. Diets included 33% dry matter (DM) of either corn (Corn TMR) or rice grains (Rice TMR). In a 48-h in vitro incubation, DM digestibility (IVDMD), neutral detergent fiber degradability (IVNDFD), crude protein digestibility (IVCPD), volatile fatty acids (VFAs), pH and ammonia nitrogen (NH₃-N) were estimated. Gas production has been calculated at 3, 6, 12, 24 and 48 h. Our results indicate that the gas production, VFAs, IVDMD, and IVNDFD of Rice TMR were higher than those of Corn TMR (p < 0.05). Ruminal pH and total fungi were significantly higher in Corn TMR (p < 0.05) than in Rice TMR; however, NH₃-N and IVCPD were not affected by treatment type. In conclusion, substituting rice for corn at 33% DM in TMR appears to have no negative effects on in vitro rumen fermentation characteristics. Therefore, rice grains are an appropriate alternative energy source in early fattening stage diets of beef cattle.

• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.437-444
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• 2011

The object of this experiment was to investigate the food habits of sika deer fed with various roughage sources. The experimental trials were conducted at Unbong Animal Genetic Resources Station in 2008. The experimental roughages include five sources and 25 species in all; grasses and legumes: 5 species (mixed grasses, orchardgrass, tall fescue, alfalfa, white clover), native grasses and weeds: 5 species (mixed native grasses, Miscanthus sinensis Anderss, Arundinella hirta (Thunb.) Tanaka, barnyard grass, short awn, forage crops (hay, silages and straw): 5 species (barley + hairy vetch, Wheat + hairy vetch, rye silage, barley silage, baled rice straw), browse and fallen leaves: 5 species (mixed browse, oriental white oak, Quercus serrta Thunb., oriental cherry fallen leaves, Japanese chestnut fallen leaves), and imported hays and straws: 5 species (timothy hay, tall fescue straw, annual ryegrass straw, klinegrass hay, alfalfa hay). Five sika deer were used as experimental animals and the averaged body weight was 95+5.4kg. The chemical composition and dry matter digestibility of each roughage source and species were significantly different at the sampling area, plant species, growth stages and cutting period(p<0.05). The sika deer ate more roughages which had low fibrous contents, but high dry matter digestibility. Among all the 25 species of roughages, the favorite intake roughage sources ranking by sika deer was observed like this: browse and fallen leaves (32.2%), grass and legumes (27.0%), native grasses and weeds (22.0%), imported hays (12.9%) and forages crops (5.5%) respectively. Although, the sika deer ate more browse leaves, but ate more roughage which had low fibrous contents (NDF and ADF), but high drymatter digestibility. On the other hand, compared to each roughage source, total intake amount by sika deer was showed as browse and fallen leaves (32.2%). Based on the result, the food habit of sika deer seems to be closer to the typical browser.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7256-7261
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• 2015

This paper devised a plant growing system As LED light source, three monochromatic lights (red, blue, white) and three mixed lights (red1+blue1, red2+blue1, red1+blue2) were made. According to the optical properties of those LED light sources and change in the amount of light, this author analyzed the characteristics of luminance and PPFD and also plant growth. According to the light efficiency of those LED light sources, it was high in white light as 125 lm/W and was low in red1+blue2 light as 9.9 lm/W. This result shows that monochromatic light has higher light efficiency than mixed light. The PPFD ($25{\mu}mol$, $50{\mu}mol$, $100{\mu}mol$) luminance in different wavelengths of LEDs was high in white LEDs and was low in blue LEDs. therefore, it is possible to devise an efficient LED lighting system appropriate for growing plants by variety monochromatic lights and mixed light wave length combination of LED light source.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.106-106
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• 2019

Human needs energy to maintain metabolisms, and these energy sources were uptake foods or nutritions. The most effective source was known for glucose among the nutrients, furthermore the glucose is an important source of energy for blood cells and control brain maintenences cells. But as food is plentiful and eating habits become more westernized, fast food and irregular meal times by works. Nowadays, diabetes were rapidly increased by malnutriton and obesity. Diabetes was the sixth highest on the list of causes of death in Korea, released by the Statistics Korea in 2015, which is considered a serious social problem for adult diseases. Therefore, this study aims to establish the optimal hot water extraction conditions of mixed herbs extract mixture compounds that are effective in diabetes. The independent factors were extraction temperature (X1: $40-120^{\circ}C$), extraction time (X2: 2-10 hrs.), and the ratio of water to sample (X3: 40-200 mg/mL). Their effects were assessed on dependent variables of the extract properties, which included soluble solid contents, Brix of sample extract, total polyphenols content, total flavonoids content and DPPH Radical scavenging activity. As a result, the content of total polyphenol content was the highest in No.12(6 hrs, $120^{\circ}C$, 67 mg/mL) and the highest total flavonoid contents was found in No.16(6 hrs, $80^{\circ}C$, 40 mg/mL). DPPH Radical scavenging activity showed the highest activity in No.7(8 hrs, $100^{\circ}C$, 100 mg/mL).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.3
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• pp.47-62
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• 2022

The Ministry of Environment has been working to reduce the impact on biodiversity, ecosystems, and social costs caused by soil runoff from highland Agricultural fields by setting up non-point pollution source management districts. To reduce soil loss, runoff path reduction technology has been applied, but it has been less cost effective. In addition, non-point pollution sources cause environmental conflicts in downstream areas, and recently highland Agricultural fields are becoming vulnerable to climate change. The Ministry of Environment is promoting the optimal management plan in earnest to convert arable land into forests and grasslands, but since non-point pollution is not a simple environmental problem, it is necessary to approach it from the aspect of NbS(Nature-Based Solution). In this study, a scenario for applying the nature-based solution was established for three subwatersheds west of Haean-myeon, Yanggu-gun, Gangwon-do. The soil loss distribution was spatialized through GeoWEPP and the amount of soil loss was compared for the non-point pollution reduction effect of mixed forests and grasslands. When cultivated land with a slope of 20% or more and ginseng fields were restored to perennial grasslands and mixed forests, non-point pollution reduction effects of about 32% and 29.000 tons compared to the current land use were shown. Also, it was confirmed that mixed forest rather than perennial grassland is an effective nature-based solution to reduce non-point pollution.

• The Korean Journal of Mycology
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• v.26 no.2 s.85
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• pp.239-245
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• 1998

The feasibility of enzymatic hydrolysis of cellulosic materials is dependent on the cost of cellulase, which is strongly influenced by the selection of proper carbon source in the cellulase production medium. When solka floc was used as a carbon source for the production of cellulase by Trichoderma reesei Rut C-30, a maximum of 53.2 U/ml of CMCase activity (4.8 U/ml of FPase activity) was obtained with a concentration of 1 % of solka floc. The cellulase activity decreased to 50% in the presence of 0.5% of glucose in the medium. The production of cellulase was considerably enhanced when solka floc and wheat bran were used together as a carbon source. A medium which contained 1 % of solka floc and 3 % of wheat bran yielded highest cellulase activity: CMCase activity of 76 U/ml and FPase activity of 12.5 U/ml.

• Solar Energy
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• v.12 no.3
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• pp.70-83
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• 1992

The interaction between the surface radiation and the mixed convection transport from an isolated thermal source, with a uniform surface heat flux input and located in a rectangular enclosure, is stuied numerically. The enclosure simulates a practical system such an air cooled electric device, where an air-stream flows through the openings on the two vertical walls. The heat source represents an electric component located in such an enclosure. The size of this cavity is $0.1[m]{\times}0.1[m]$. The inlet velocity is assumed as 0.07[m/s] and the inlet temperature is maintained as $27^{\circ}C$. The inflow is kept at a fixed position. Laminar, two dimensional flow is assumed, and the problem lies in the mixed convection regime, governed by buoyancy force and surface readiation. The significant variables include the location of the out-flow opening, of the heat source and the wall emissivity. The basic nature of the resulting interaction betwwn the externally induced air stream and the buoyancy-driven flow generated by the source is investigated. As a result, the best location of the heat source to make the active heat transfer is 0.075[m] from the left wall on the floor. The trends observed are also discussed in terms of heat removal from practical systems such as electric circuitry.