• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.1017-1024
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• 2014

This study was carried out to develop mulberry wines fermented with traditional microorganisms (Saccharomyces cerevisiae B-8). S. cerevisiae B-8 is a traditional fermentation microorganism isolated from domestically grown Rubus occidentalis. Each S. cerevisiae B-8 and Fermivin was inoculated into mulberry up to $1{\times}10^9$ CFU/kg, followed by incubation at $25^{\circ}C$ for 10 days. Mulberry fermented with S. cerevisiae B-8 (MBB) had a high alcohol content (16.47%), and the fermentation rate of MBB was faster than that of mulberry fermented with Fermivin (MBF). The total polyphenol and flavonoid contents of MBB were higher than those of MBF. DPPH radical scavenging activity of MBB was as high as that of MBF. ABTS radical scavenging activity of MBF was higher than those of MBB and mulberry juice (MBJ). In addition, reducing power of MBB was much higher than other samples. Flavor constituents of the two fermented wines were analyzed by gas chromatography and mass spectrometry. Twenty-three compounds from the sample were separated and identified as fifteen esters, six alcohols, an aldehyde, and an acetate. Particularly, tetradecanoic acid, ethyl ester of orris and violet flavor were ten times more abundant in MBB than in MBF. Several ester components were two times more abundant in MBB than in MBF. In conclusion, current findings indicate that MBB might have better antioxidant activities with flavor, which contributes to improved wine production with high quality and function.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.253-262
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• 2013

This experiment was conducted to investigate the effects of floor type and heating system on performance, housing environment and health status of ducks reared in three types of duck house (OD : Open floor house-Direct heating system, OF : Open floor house-Floor heating system and LD : Loft type house-Direct heating system). In OF treatment, PVC pipes were installed for heating under concrete floor and covered with litter. In LD treatment, plastic mesh was installed 50 cm above the floor so that duck's droppings can pass through it. Each treatment had four replicates of 25 birds (Cherry Valley duck breed) per pen. There were no significant differences in weight gain and feed intake of ducks for 6 weeks among all treatments. However, feed conversion ratio in LD was significantly higher (p<0.05) than that in OF. No differences were found in carcass charac- teristics, with the exception of abdominal fat weight where OF were higher than the others. Concentrations of $CO_2$ and $NH_3$ gas in OD were higher than those of OF and LD at 3, 4 and 5 weeks. Moisture content in litter of OF was lower than that of OD. In contrast, the amount of dust in the air was higher in OF than in OD. The amount of fuel used for 6 weeks in LD was lower about 21% than that in OD. Some of unusual symptoms were observed in open floor house and loft type house, such as lying, spraddle legged, twisted ankle and legs, wounded sole, or etc. No components of leukocyte and erythrocyte of blood were significantly different among all treatments. The results of this experiment showed that OF and LD systems had no positive effects on performance of meat type commercial duck. However, there were some positive effects of certain house type for the improvement of environmental condition in duck house for hygienic production. In the future, more research on the effect of various facilities and systems for duck house is needed.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.390-399
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• 2016

Purpose: The objective of this study was to examine the effect of plant scale and cooking conditions on the quality characteristics of sausages during refrigerated storage. Methods: Sausages used in this study were classified into two groups: those submitted to $1^{st}$ cooked treatments and those submitted to $2^{nd}$ cooked treatments. The pH, volatile basic nitrogen (VBN), gas production ratio, and microorganisms were measured in triplicate. Results: The change of quality in the products was assessed every 7 days by measuring pH, VBN levels, total microbes, coliform bacteria, Escherichia coli, and pathogenic bacteria in the products. Pathogenic bacteria such as Staphylococcus aureus, Listeria monocytogenes, Clostridium perfringens, and E. coli were not detected in the sausages with $1^{st}$ cooked treatments. The results showed that the pH of the sausages decline as storage time increased. The pH value of the sausages with $2^{nd}$ cooked treatments changed gradually. VBN levels were generally lower in products with $2^{nd}$ cooked treatments than in those with $1^{st}$ cooked treatments, but they varied with the type of products. On the $35^{th}$ day, the number of total microbes ranged between 6.13-7.12 log CFU/g in products with $1^{st}$ cooked treatments and 3.44-6.92 log CFU/g in products with $2^{nd}$ cooked treatments, showing fewer bacteria in the latter products. Conclusions: $1^{st}$ cooked treatments were effective in microbial control, but $2^{nd}$ cooked treatments could prolong the shelf life of the sausages, indicating a need for differential management of each product.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.35-45
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• 1997

This study has been carried out to estimate carbon fixation, and carbon NPP based on equation form of $Wt=aD^bH^c$ in natural stand of Quercus mongolica and Quercus variabilis in Chungju. The effect of improvement of environment was also evaluated by estimating sink of $CO_2$ gas in forest ecosystem of Korea in a year. The following effects have been obtained in analysing estimate of allometric equation. Equation form of $Wt=aD^bH^c$ was the most adequate, those of $Wt=a(D^2H)^b$, $Wt=aD^b$ estimate of the biomass and the carbon fixation in Quercus natural stand of Chungju. Total above ground of Quercus mongolica was 130.58 t/ha and that of Quercus variabilis was 137.38 t/ha. Annual production of two stands was 9.96 t/ha/yr, 8.64 t/ha/yr, respectively. Carbon fixation of total above ground was 60.52t C/ha in Quercus mongolica stand, and was 62.22t C/ha in Quercus variabilis stand. Annual fixation of carbon was 4.78t C/ha/yr and 4.28t C/ha/yr, seperately. Annual emission of carbon estimated 2.44t C/ha/yr in contrast of forest area in Korea. It was showed that the annual fixation of carbon was higher 1.84t C/ha/yr~2.34t C/ha/yr than annual emission of carbon. But foliage was 2.39t C/ha/yr and 1.89t C/ha/yr, which occupied 40% and 50% of annual carbon fixation of total above ground. Annual carbon fixation may fluctuate about 1.89t C/ha/yr~2.39t C/ha/yr by seasons.

• Journal of Life Science
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• v.22 no.10
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• pp.1324-1329
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• 2012

The objective of this study was to evaluate the in vitro effects of organic acids on methane emission and ruminal fermentation characteristics. We expected our methodology to result in a decrease of methanogens attached to the surface of rumen ciliate protozoa by addition of organic acids and in particular a decrease in methane emission. A fistulated Holstein cow of 650 kg body weight was used as a donor of rumen fluid. Organic acids (aspartic acid, fumaric acid, lactic acid, malic acid, and succinic acid) known to be propionate enhancers were added to an in vitro fermentation system and incubated with rumen fluid. The microbial population, including bacteria, protozoa, and fungi, were enumerated, and gas production, including methane and fermentation characteristics, were observed in vitro. Organic acids appeared to affect the rumen protozoan community. The rumen protozoal popuation decreased with the addition of aspartic acid, fumaric acid, lactic acid, and malic acid. In particular, the methane emission was reduced by addition of lactic acid. The concentration of propionate with all organic acids that were added appeared to be higher than that of the control at 12 h incubation. Addition of organic acids significantly affected rumen bacteria and microbial growth. The bacteria in added fumaric acid and malic acid was significantly higher (p<0.05) and protozoa was significantly lower (p<0.05) than that of the control. Microbial growth with the addition of organic acids was greater than the control after 48 h incubation.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.29-39
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• 2009

The influence of windbreak to minimize the ventilation velocity near the plant canopy of a greenhouse strawberry was thoroughly investigated using computational fluid dynamics (CFD) technology. Windbreaks were constructed surrounding the plant canopy to control ventilation and maintain the concentration of the supplied $CO_2$ from the soil surface close to the strawberry plants. The influence of no windbreak, 0.15 m and 0.30 m height windbreaks with varied air velocity of 0.5, 1.0 and 1.5 m/s were simulated in the study. The concentrations of supplied $CO_2$ within the plant canopy of were measured. To simplify the model, plants were not included in the final model. Considering 1.0m/s wind velocity which is the normal wind velocity of greenhouses, the concentrations of $CO_2$ were approximately 420, 580 and 653 ppm ($1{\times}10^{-9}kg/m^3$) for no windbreak, 0.15 and 0.30 m windbreak height, respectively. Considering that the maximum concentration of $CO_2$ for the strawberry plants was around 600-800 ppm, the 0.30 m windbreak height is highly recommended. This study revealed that the windbreak was very effective in preserving $CO_2$ gas within the plant canopy. More so, the study also proved that the CFD technique can be used to determine the concentration of $CO_2$ within the plant canopy for the plants consumption at any designed condition. For an in-depth application of this study, the plants as well as the different conditions for $CO_2$ utilization, etc. should be considered.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1213-1221
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• 2006

In this study, granular sludge used in an anaerobic process treating brewery waste was inoculated in a laboratory scale of reactor to induce anaerobic ammonium oxidation(ANAMMOX). The reactor was operated with synthetic wastewater, which prepared at 1:1 ratio of $NH_4^+-N$ over $NO_2^--N$. Changes in nitrogen concentration, COD, alkalinity and gas production were analyzed. There are 3 phases of spanning in experimental period according to influent nitrogen concentration. In the Phase 1, each of the concentration of $NH_4^+-N$ and $NO_2^--N$ were increased from 1.91 $gN/m^3{\cdot}d$ to 14.29 $gN/m^3{\cdot}d$. Ammonium nitrogen loading(same as nitrite nitrogen) was 23.81 $gN/m^3{\cdot}d$ in the Phase 2 and 19.05 $gN/m^3{\cdot}d$ in the Phase 3, respectively $NO_2^--N$ has been removed up to 99% during whole period while the removal efficiency of $NH_4^+-N$ was significantly varied. In Phase 2, $NH_4^+-N$ was removed up to 75%. Microorganisms varied temporally through three phases were characterized by 16s rDNA analysis methods. ANAMMOX bacteria were dominantly found in phase 2 when the removal rate of $NO_2^--N$and $NH_4^+-N$ was the highest up to 99% and 75%, respectively. Due to erroneous exposed to air, the removal efficiency of $NH_4^+-N$ was unexpectedly lowered, but ANAMMOX bacteria still existed.

• Korean Journal of Environmental Biology
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• v.32 no.1
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• pp.58-67
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• 2014

The outdoor mass cultivation is not possible for microalgae in Korea all year round, due to cold winter season. It is not easy to maintain proper level of productivity of microalgae even in winter. To prevent a drastic decrease of temperature in a greenhouse, two layers were covered additionally, inside the original plastic layer of the greenhouse. The middle layer was made up of plastic and the inner layer, of non-woven fabric. Acrylic transparent bioreactors were constructed to get more sunlight, not only from the upper side but also from the lateral and bottom directions. In winter at freezing temperatures, six different culture conditions were compared in the triply covered, insulated greenhouse. Wastewater after anaerobic digestion was used for the cultivation of microalgae to minimize the production cost. Water temperature in the bioreactors remained above $10^{\circ}C$ on average, even without any external heating system, proving that the triple-layered greenhouse is effective in keeping heat. Algal biomass reached to 0.37g $L^{-1}$ with the highest temperature, in the experimental group of light-reflection board at the bottom, with nitrogen and phosphorus removal rate of 92% and 99%, respectively. When fatty acid composition was analyzed using gas-chromatography, linoleate (C18 : 3n3) occupied the highest proportion up to 61%, in the all experiment groups. Chemical oxygen demand (COD), however, did not decrease during the cultivation, but rather increased. Although the algal biomass productivity was not comparable to warm seasons, it was possible to maintain water temperature for algae cultivation even in the coldest season, at the minimum cost.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.20-24
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• 2013

Food irradiation has recently become one of the most successful techniques to preserve food with increased shelf life. This study aims to analyze hydrocarbons in almonds (Prunus amygosalus L.) and peanuts (Arachis hypogaea) induced by electron beam irradiation. The samples were irradiated at 0, 1, 3, 5 and 10 kGy by e-beam and using florisil column chromatography fat, and content was extracted. The induced hydrocarbons were identified using gas chromatography-mass spectrometry (GC/MS). The major hydrocarbons in both irradiated samples were 1,7-hexadecadiene ($C_{16:2}$) and 8-heptadecene ($C_{17:1}$) from oleic acid, 1,7,10-hexadecatriene ($C_{16:3}$) and 6,9-heptadecadiene ($C_{17:2}$) from linoleic acid and 1-tetradecene ($C_{14:1}$) and pentadecane ($C_{15:0}$) from palmitic acid. Concentrations of the hydrocarbons produced by e-beam were found to be depended upon the composition of fatty acid in both almonds and peanuts. The $C_{n-2}$ compound was found to be higher than $C_{n-1}$ compound in oleic acid and palmitic acid, while in case of linoleic acid, $C_{n-1}$compound was higher than $C_{n-2}$ compound. The radiation induced hydrocarbons were detected only in irradiated samples, with 1 kGy or above, and not in the non-irradiated ones. The production of 1,7-hexadecadiene ($C_{16:2}$), 8-heptadecene ($C_{17:1}$), 1,7,10-hexadecatriene ($C_{16:3}$) and 6,9-heptadecadiene ($C_{17:2}$), in high concentration gave enough information to suggest that these may be the possible marker compounds of electron beam irradiation in almonds and peanuts.

• Fire Science and Engineering
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• v.31 no.5
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• pp.53-62
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• 2017

Electric power which is the energy source of economy and industries requires long distance transportation due to regional difference between its production and consumption, and it is supplied through the multi-loop transmission and distribution system. Prior to its actual use, electric power flows through several transformations by voltage transformers in substations depending on the characteristics of each usage, and a transformer has the structure consisting of the main body, winding wire, insulating oil and bushings. A transformer fire that breaks out in substations entails the primary damage that interrupts the power supply to houses and commercial facilities and causes various safety accidents as well as the secondary economic losses. It is considered that causes of such fire include the leak of insulating oil resulting from the destruction of bottom part of bushings, and the chain reaction of fire due to insulating oil that reaches its ignition point within 1 second. The smoke detector and automatic fire extinguishing system are established in order to minimize fire damage, but a difficulty in securing golden time for extinguishing fire due to delay in the operation of detector and release of gas from the extinguishing system has become a problem. Accordingly, this study was carried out according to needs of active mechanism to prevent the spread of fire and block the leak of insulating oil, in accordance with the importance of securing golden time in extinguishing a fire in its early stage. A bushings fireproof structure was developed by applying the high temperature shape retention materials, which are expanded by flame, and mechanical flame cutoff devices. The bushings fireproof structure was installed on the transformer model produced by applying the actual standards of bushings and flange, and the full scale fire test was carried out. It was confirmed that the bushings fireproof structure operated at accurate position and height within 3 seconds from the flame initiation. It is considered that it could block the spread of flame effectively in the event of actual transformer fire.