• Journal of Bio-Environment Control
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• v.2 no.1
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• pp.65-68
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• 1993

탄산가스는 탄소나 그 화합물이 완전연소할 때, 생물이 호흡할 때, 발효 등에 의하여 생성되는 무색, 무취의 기체로 분자식은 $CO_2$(이산화탄소)이며, 분자량은 44, 비중은 공기 1에 대하여 1.529이다. 식물은 탄산가스와 물을 원료로 태양에너지를 이용하여 탄수화물을 합성하므로 탄산가스는 광합성에 절대적으로 필요하며, 탄산가스가 충분하게 공급되지 않으면 광합성이 원활하게 이루어질 수가 없다. 일반적으로 식물은 대기중의 농도(0.03%)보다 높은 농도에서 포화점을 갖고 있으므로 대기중에서의 탄산가스의 농도는 식물의 광합성작용에 충분하지 못하며, 생육촉진을 위해서는 인위적인 방법으로 탄산가스 농도를 증가시키는 방법이 실용화되고 있다.(중략)

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.137.1-137
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• 2003

본 연구는 저장 중 부패된 복숭아(‘황도’)에서 Botrytis cinerea를 분리한 후 $25^{\circ}C$에서 배양 중 고농도 탄산가스 (35, 60, 100% + 24, 48, 72시간) 환경에서의 생장억제 효과를 구명하고 이에 따른 과실의 품질 변화를 고찰하였다. 실시한 모든 처리 농도에서 곰팡이 생장이 억제되었으며, 가스 농도 및 처리 시간의 증가에 의해 효과가 극대화되었다. 특히, 100% 탄산가스를 24, 48, 72시간 처리할 경우 5일 배양 후 곰팡이의 생장 정도는 무처리구에 비해 각각 25, 39, 46% 감소되었다. 고농도 탄산가스 처리 기간 동안 곰팡이 성장은 억제되었고 가스 환경이 제거될 경우 정상적인 생장을 재개하는 양상을 보였다. 수확된 ‘황도’ 과실을 대상으로 가스처리 효과를 검증한 결과 100% + 24, 48시간, 60% + 48시간 처리가 부패억제에 효과적인 것으로 나타났다. 35% 농도의 경우 효과가 미미하였다. 가스 처리에 따른 과실의 당도 변화는 없었으며 100% + 48시간 처리의 경우 경도가 높게 유지되었다.

• Journal of the Korea Computer Industry Society
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• v.9 no.4
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• pp.143-148
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• 2008

The major influence factor on carbonation of concrete structures is carbon dioxide concentration. In this study, carbonation analyses with carbon dioxide concentration were carried out by the developed program. Also, the service life of concrete strucures was predicted. The carbonation depth was 50mm in case that carbon dioxide concentration wad 0.1%. It was shown that the service life of concrete structures with 40mm cover depth was 67 years even though they had been exposed at carbon dioxide concentration 0.1% during 100 years.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.461-467
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• 1989

The effect of $CO_2$ concentration on the post-harvest physiology and quality of Shiitake mushroom (Lentinus edodes) were investigated during CA storage. The respiratory rates of the mushroom stored in CA conditions were abruptly increased in proportion to $CO_2$ concentration after 40 days, and then declined, while that of the mushroom in air was continuously decreased throughout storage period. Large amounts of ethanol and acetaldehyde were produced from the 20 days CA stored mushrooms. The least changes in 5'-GMP content and electrophoresis pattern of protein in the mushroom were observed at $CO_2$ concentration of 2% during storage. Based on the changes in quality factors of the mushroom during storage, it could be concluded that $CO_2$ concentration of 2% with fixed $O_2$ concentration of 2% was more effective in extension of the freshness than any other $CO_2$ level in this experiment.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.6
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• pp.559-564
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• 2016

We investigated the effect of calcium carbonate on the quality of wine obtained from Gaeryangmerou (Vitis. spp.), grapes, which are commonly used in wine making in Korea. Alcoholic fermentation was carried out at $25^{\circ}C$, for 7 days in the presence of 0.1%, 0.2%, and 0.3% calcium carbonate. As calcium carbonate concentration increased, the pH of wine increased, while its total acid content and redness decreased. Calcium carbonate treatment during precipitation and aging is more effective than during fermentation. Concentrations of alcohol, total anthocyanin, polyphenol, and tannin showed no significant differences between controls and deacidified groups. Tartaric and malic acids were found to be the major acids in Gaeryangmerou wine. Calcium carbonate reduced total acidity by precipitating tartaric acid. In the sensory evaluation of the acidity, and overall acceptability, wine treated with 0.1% calcium carbonate was the best. Higher calcium carbonate concentration, was associated with greater reduction in total wine acidity. However, it is necessary to maintain the calcium carbonate concentration within 0.1% since excessive amounts of calcium carbonate can have a negative effect on wine quality.

• Food Science and Preservation
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• v.20 no.1
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• pp.76-80
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• 2013

This study investigated the textural changes after the calcium-pectin bonding of ginseng roots and their vinegar and calcium solution immersion. The strength and breakdown of the ginseng roots increased according to the increase in the calcium carbonate concentration, with the highest in the 0.7~1.0% calcium carbonate. The hardest and softest ginseng roots were obtained in the 1.0% calcium carbonate concentration. The strength, brittleness and hardness of the ginseng roots that were soaked in 1% calcium carbonate and 5~6% acidity vinegar continued to increase with the long-term storage of the ginseng root drink. The softness of the ginseng root that was dipped in 5% acidity vinegar with 1.0% calcium carbonate decreased with the long-term storage of the ginseng root drink. Thus, calcium and vinegar immersion of ginseng roots could prevent softening and clouding during the long-term storage of the ginseng root drink.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2017.05a
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• pp.150.1-150.1
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• 2017

구조용 합금 중 가장 우수한 비강도를 나타내는 마그네슘 및 마그네슘 합금은 최근 자동차, 항공, 기계 및 전자산업 등 다양한 산업분야에서 이용되고 있다. 하지만 마그네슘 합금은 반응성이 매우 커서 쉽게 부식되는 단점이 있다. 따라서 최근 내식성 향상을 위한 표면처리 기술에 대한 연구의 필요성이 증대되고 있으며, 그 중 플라즈마 전해산화법(Plasma electrolytic oxidation)은 양극산화반응을 이용하여 고내식성, 고경도의 산화피막을 금속 표면에 형성시키는 방법으로 많은 연구가 진행되고 있다. 본 연구에서는 탄산이온이 포함된 수용액에서 수산화나트륨의 농도가 AZ31 마그네슘 합금의 플라즈마전해산화 피막형성에 미치는 영향에 대해 알아보았다. 다양한 농도의 수산화나트륨 용액에서 DC 전류를 인가하여 플라즈마전해산화 피막을 형성하였다. 탄산 이온이 포함된 수용액에서 수산화나트륨의 농도가 높아질수록 플라즈마 전해산화 피막의 형성전압은 낮아지며, 초기 피막 형성전압 상승 속도 또한 빠르게 증가하며 피막 형성전압 등락의 폭은 감소하는 것으로 나타났다.

• Current Research on Agriculture and Life Sciences
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• v.8
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• pp.83-88
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• 1990

This experiment was conducted to investigate the effect of $CO_2$ treatment on quality of strawberry during storage. Gas composition in polyethylene(P.E.) film bag during storage was changed markedly at early stage of storage and then kept at the level of 8-9% $CO_2$and 1-2% $O_2$. Weight loss and decay were restricted by $CO_2$ pretreatment and P.E. film packaging. Titratable acidity, PH and soluble solids were not changed greatly during storage. Firmness of flesh was increased by $CO_2$ treatment till 14 days of storage and decrease of a value reduced by $CO_2$ treatment and P.E.film packaging, too. Ascorbic acid contents were more high in not packed samples than packed untill 14 days of storage but after that those were more high in P.E.film packed and $CO_2$ treated samples.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.149-156
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• 2014

The objective of this research was to investigate the influence of bicarbonate ($HCO_3{^-}$) concentrations in nutrient solution on the growth and physiological disorders in mother plants and occurrence of daughter plants in propagation of 'Seolhyang' strawberry (Fragaria ${\times}$ ananassa Duch.). To achieve this, the mother plants were transplanted to coir dust + perlite (7:3, v/v) medium and Hoagland solution was modified to contain 60, 90 (control), 120, 180, and $240mg{\cdot}L^{-1}$ of $HCO_3{^-}$. The symptoms of Fe, Zn and B deficiencies appeared on the mother plants in the $HCO_3{^-}$ of $240mg{\cdot}L^{-1}$ from the 60th day after treatment. The symptoms spread to all plants in the $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ including daughter plants at 90 days after treatment. The$HCO_3{^-}$ concentrations higher than $120mg{\cdot}L^{-1}$ suppressed the growth of mother plants such as leaf number, chlorophyll content, fresh weight and other growth parameters. While the mother plants in $60mg{\cdot}L^{-1}$ $HCO_3{^-}$ produced 23 daughter plants, while mother plants in $240mg{\cdot}L^{-1}$ $HCO_3{^-}$ produced 13 daughter plants. The final pH 126 days after treatment in the $HCO_3{^-}$ of 60, 90, 120, 180 and $240mg{\cdot}L^{-1}$ were 5.4, 5.8, 7.3, 7.9, and 8.3, respectively. The elevation of $HCO_3{^-}$ concentrations in nutrient solution resulted in the decrease of Fe, Mn, Zn and Cu contents of above ground tissue 126 days after treatment. These results indicate that the $HCO_3{^-}$ concentrations higher than $120mg{\cdot}L^{-1}$ inhibited the growth of mother plants and occurrence of daughter plants in vegetative propagation of 'Seolhyang' strawberry.

• Journal of Bio-Environment Control
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• v.22 no.1
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• pp.65-72
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• 2013

This study was conducted to investigate the influences of bicarbonate ($HCO_3^-$) concentrations in irrigation solution on growth of lettuce and change in chemical properties of root media. The blue leaf and red leaf lettuces with two true leaf stages were transplanted into 10 cm diameter plastic pots filled with perlite. The five treatments were made by dissolving $NaHCO_3$ into irrigation solution to reach 30, 70, 110, 150 and $180mg{\cdot}L^{-1}$ $HCO_3^-$. The crops were fed with fertilizer solution contained $HCO_3^-$ with various concentrations and controlled to $100mg{\cdot}L^{-1}$ in nitrogen concentration. The pH in soil solution of root media 10 weeks after transplant of blue lettuces were 7.04 and 7.10 in the treatments of 30 and $70mg{\cdot}L^{-1}$ of $HCO_3^-$, respectively. But those rose gradually after week 3 and finally reached 7.39, 7.48 and 7.56 at week 10 in the treatments of 110, 150 and $180mg{\cdot}L^{-1}\;HCO_3^-$, respectively. The pH in the treatments of 30 and $70mg{\cdot}L^{-1}\;HCO_3^-$ in cultivation of red leaf lettuce were around 6.65 during week 4 to week 8, but this rose abruptly and reached 6.92 and 7.01 at week 10, respectively. Those in the treatments of 110, 150, and $180mg{\cdot}L^{-1}\;HCO_3^-$ rose gradually and finally reached to 7.49, 7.53, and 7.58, respectively. The EC rose gradually after week 2 in all treatments of blue and red leaf lettuces. The change of macro ion concentrations in both blue and red leaf lettuces showed similar trends. The concentrations of $PO_4-P$, $Ca^{2+}$ and $Mg^{2+}$ increased gradually in all treatments of $HCO_3^-$ during cultivation of blue and red leaf lettuces. As the concentrations of $HCO_3^-$ in irrigation solution were elevated, the concentrations of $PO_4-P$, $Ca^{2+}$ and $Mg^{2+}$ became higher and that of ${SO_4}^{-2}$ became lower in soil solution of root media. The main reason of concentration changes were that $HCO_3^-$ influenced pH and the pH changes also affect the activities of the ions in soil solution of root media.