• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.2
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• pp.45-49
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• 2006

Electrochemical hydrogenation/dehydrogenation properties were studied for a single particle of a Mm-based(Mm : minh metal) hydrogen storage alloy($MmNi_{3.55}Co_{0.75}Mn_{0.4}Al_{0.3}$) for fuel cell and Ni-MH batteries. A carbon fiber microelectrode was manipulated to make electrical contact with an alloy particle, and the potential-step experiment was carried out to determine the apparent chemical diffusion coefficient of hydrogen atom($D_{app}$) in the alloy. Since the alloy particle we used here was a dense, conductive sphere, the spherical diffusion model was employed for data analysis. $D_{app}$ was found to vary the order between $10^{-9}\;and\;10^{-10}[cm^2/s]$ over the course of hydrogenation and dehydrogenation process. Compared with the conventional composite film electrodes, the single particle measurements using the microelectrode gave more detailed, true information about the hydrogen storage alloy.

• The Korean Journal of Mycology
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• v.6 no.1
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• pp.29-41
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• 1978

This study aims to brew apple wine containing lower concentration of alcohol by fermentation and to retain $CO_2$ gas in apple wine, and investigation for the possibility of storage at room temperature was performed. A Saccharomyces sp. was proved to be acceptable for production of base wine as its higher fermentation rate at $20{\sim}25^{\circ}C$. However, B-2 was most reasonable for post-fermentation of apple wine as this strain strongly ferments sugars at low temperature $(4^{\circ}C)$. The yield of apple juice increased by maceration of apple pulps. The yield was about 5 % more than that of the unmacerated juice, whereas acid content was decreased by 10% compared with control. When stored apple wine containing 9% alcobol was introduced $1{\sim}3%$ sucrose at $7{\sim}8^{\circ}C$ for 100 days or more, the $CO_2$ pressure of apple wine in bottle shows $3kg/cm^2$ by bottle-pressure meter. It showed good storage of the wine at room temperature. $CO_2$ gas pressure in apple wine containing 6% alcohol, $5{\sim}10%$ hop extract, and 2% sugar was $2kg/cm^2$, he result also showed possibility of storage. Whereas 6% concentration of alcoholic apple wine without hop extract caused unusual fermentation during storage at the same condition. The desirable conditions for high quality apple wine should have $CO_2$ pressure of $2kg/cm^2$ or more and should be added $1{\sim}2% sugar to base wine. From these results, it can be concluded that the brewing of lower alcoholic apple wine is possible.

• Journal of Biosystems Engineering
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• v.33 no.3
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• pp.167-172
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• 2008

The objective of this study was to investigate the adequate storage method that was able to maintain the high quality of rough rice according to storage methods and period. The quality change of the rough rice during the storage period was evaluated by storage method such as cooling bin using winter cold air, ordinary temperature bin, freezing, refrigeration and indoor storage. Moisture content, brown rice whiteness, hardness, crack ratio and germination ratio were measured in this study. Moisture content of rough rice stored in cooling bin using winter cold air and ordinary temperature bin were decreased by 0.07% and 0.42%, respectively, which were lower than the other storage method. The hardness of brown rice increased in order of storage method such as winter cooling bin, normal bin, freezing storage, refrigeration storage and indoor storage. Crack ratio by indoor and ordinary temperature bin storage were increased by 2.68% and 3.63%, respectively, whereas cooling bin using winter cold air, refrigeration and freezing storage showed below 1.0%. The highest germination rate was found in cooling bin using winter cold air. As a result, cooling bin using winter cold air can be evaluated for the adequate storage method of rough rice.

• Food Science of Animal Resources
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• v.32 no.3
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• pp.346-353
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• 2012

This study was carried out in order to investigate the relationship of antioxidant enzyme activity, lipid oxidation, and aroma pattern of Hanwoo (Korean cattle) beef for 8 d at $15^{\circ}C/RH$ 100% under 0% $O_2$/20% $CO_2/80%\;N_2$, 25% $O_2$/20% $CO_2/55%\;N_2$, 50% $O_2$/20% $CO_2/30%\;N_2$, and 75% $O_2$/20% $CO_2/5%\;N_2$-conditions. The reduction of $O_2$ and the induction of $CO_2$ were shown in the 25-75% $O_2$-groups during storage and total change rates of $O_2$ and $CO_2$ were followed in order: 25%>50%>75%. Catalase activity was not significantly different among all groups. During storage, glutathione peroxidase activity decreased by increasing the $O_2$ concentration and was followed at 8 d in order: 0%>25%>50%>75% (p<0.05). From 2 d of storage, TBARS content had significant (p<0.05) differences in order: 0%>25%>50%>75%. The CIE $L^*$ value was higher (p<0.05) in the 25-75% $O_2$-groups, compared with the 0% $O_2$-group. During the first time, the CIE $a^*$ value was higher (p<0.05) in order: 0%<25%<50%<75% but was lower (p<0.05) in the 25-75% $O_2$-groups from 2 d of storage than in the 0% $O_2$-group. The CIE $b^*$ value was higher (p<0.05) in the 25-75% $O_2$-groups than in the 0% $O_2$-group and had significant (p<0.05) differences at 0 and 8 d in order: 0%<25%<50%<75%. Aroma patterns with the electronic nose were clearly discriminated between the 0% $O_2$-groups and the 25-75% $O_2$-groups at 8 d of storage. Therefore, high oxygen reduced stabilities of antioxidant enzymes, lipid oxidation, and color in Hanwoo beef. Furthermore, antioxidant enzyme activities and lipid oxidation could affect aroma patterns.

• Food Science and Preservation
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• v.4 no.3
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• pp.265-270
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• 1997

Effect of modified atmosphere packaging conditions on quality changes of dry jujube was investigated. Dry jujubes with moisture content of 26.7% were packaged in PET/Al/PE film pouches with modified atmospheres. The tested packages include those with normal air, vacuum, CO2 flushing, N2 flushing and O2 scavenger. Packages were stored at 25$^{\circ}C$ for 6 months, during which ascorbic acid concentration, browning level, titratable acidity and surface color were measured. Generally modified atmosphere packages could improve quality retention of dry jujubes except that vacuum package resulted in large surface color change. CO2-flushed package showed the best quality retention of high ascorbic acid content and low browning during 112 days, but caused high amounts of ascorbic acid destruction and browning in longer storage. In all the modified atmosphere packages titratable acidity reached a maximum followed by decline and subsequent rise, while it increased linearly with time in normal air package. Considering ascorbic acid retention browning level and surface color changes during 112 days, the packages of CO2 flushing and N2 flushing were better than others.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.123-128
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• 2013

Carbon dioxide Capture and Storage (CCS) is one of the key players in greenhouse gas (GHG) reduction portfolio for mitigating climate change. CCS makes it possible not only to reduce a huge amount of carbon dioxide directly from coal power plant but also to maintain the carbon concentrated-energy infrastructure. The objective of the present paper is to review and introduce R&D progress and large scale demonstration plan focused on marine geological storage in Republic of Korea.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.547-551
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• 2008

The study aimed to develop a cryopreservation method for long-term storage using mature somatic embryo of Japanese larch. In this study, desiccation treatments significantly affected re-induction rates of embryogenic tissue (ET) from dried somatic embryos. In the effect of different dehydration temperature and duration on the re-initiation ET. the highest frequency was shown when somatic embryos were dehydrated at $25^{\circ}C$ for 2 (45.5%) or 1 day (43.3%), respectively. In addition, low temperatures [$4^{\circ}C$, 2 days (44.2%) or 3 days (43.5%)] were marked higher ET initiation. After that, the initiation value was declined with dehydration duration. For comparison of different relative humidity on re-induction frequency of ET, the best re-induction (43.5%) was obtained from somatic embryos pre-dried at $(NH_4)_2SO_4$ (RH 79%). Both $Na_2HPO_4$ (RH 97%) and $Na_2CO_3$ (RH 88%) treatments were showed the similar rate, 34.6, 34.2%, respectively. However the lowest rate (19.6%) was observed in distilled water (RH 100%). In comparison of the various storage temperatures and duration of the dried somatic embryos, the highest frequency (66.9%) of re-initiation was obtained when somatic embryos were cryopreserved for one day. However, the frequency was gradually decreased as the time length of storage increased regardless of types of storage. None of ET re-initiated when stored at $4^{\circ}C$ for 1, 2 and 84 days.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.127-131
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• 2007

In order to investigate the presence of pathogenic bacteria in fresh pig loin and the growth changes of microorganism in raw ham during storage at 10 and $25^{\circ}C$. These hams were manufactured according to a short-ripening procedure being completed in 4 weeks with dry-curing followed by wet-curing and ripening. The result regarding the contamination level of microorganism in the fresh raw pig loin showed that the count of total aerobes was $3.11\;log\;CFU/cm^2$, and the population of lactic acid bacteria, Pseudomonas spp., Clostridium spp., and yeast and mould had not risen over $2\;log\;CFU/cm^2$ on the storage time. However, the average count ofEnterobacteriaceae in pork loin was $3.11\;log\;CFU/cm^2$, which represented the predominant species. The pathogenic bacteria including Salmonella spp, Staphylococcus aureus, Vibrio parahaemolyticus, Clostridium perfringene, Listeria monocytogenes, and Escherichia coli O157:H7 were not detected either in fresh pork loin or in raw ham products stored at 10 and $25^{\circ}C$. The initial count of total aerobes in raw ham samples was 3.06 log CFU/g, and increased slightly after 90 days at 10 and $25^{\circ}C$ to 4.6 and 4.69 log CFU/g, respectively. The predominant species in raw ham products during storage time were lactic acid bacteria and Staphylococcus spp.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.861-865
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• 2005

2,4-Dinitrophenylhydrazine (DHP), indophenol, and HPLC methods, which are generally used to analyze vitamin C, were evaluated by comparing changes in vitamin C contents in various samples kept at 10 and $20^{\circ}C$. Amount of total ascorbic acid (TAA) in yoghurt A kept at $10^{\circ}C$, as measured by DNP method, decreased from 26.7mg/100mL for early period to 22.8mg/100mL for final period of storage, whereas, on 3rd and 10th storage days, increased contrary to general results. Using indophenol, TAA measured at 28.6 and 9.5mg/100mL, and 30.5 and 14.6mg/100mL using HPLC far early and final periods, respectively. With indophenol and HPLC, TAA amount showed steady tendency to decrease. In conclusion, HPLC is the most suitable method to analyze vitamin C content, and indophenol method can be also used during early storage stage.

• Food Science and Preservation
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• v.13 no.1
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• pp.1-7
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• 2006

The effects of packaging material and method on quality of fresh-cut mushrooms (Agaricus bisporus Sing.) were investigated in terms of weight loss, surface color, phenolics, vitamin C and sensory characteristics during storage at $5^{\circ}C$. The fresh-cut mushrooms were subjected to passive, gas exchange and vacuum packaging conditions at st. Polyethylene film (PE), polypropylene film (PP), anti-fogging film (AP) and pen orated film (PF) were used for the passive packaging. The mixed gas of $5\% CO_2/\;2\%O_2$ (MA1) and $10\%CO_2/\;2\%O_2$(MA2) were applied for the gas exchange packaging. The respiration rate of sliced mushroom was 1.27 times higher than intact mushroom at $5^{\circ}C$. Gas concentrations in the passive packaging were $1-2\%\;O^2\;and\;5-16\%m$ during storage of sliced mushrooms for 14 days at $5^{\circ}C$, and levels of the gases were different by the films used The mushroom in perforated film (PF) showed the highest weight loss of $4.56\%$. Anti-fogging film (AF) was somewhat effective for prevention of the weight loss compared with other films after 14 days storage. The mushrooms in MA1 and MA2 packages showed lower delta L value than in other films. PE packaging mitigated decrease of free and bound phenolics during storage. The mushrooms in MA2 kept better quality in sensory aspect, and then in MA1, PE and PP in order during storage at $5^{\circ}C$.