• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.25 no.2
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• pp.31-35
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• 2019

Kimchi is a refreshing sour food which gives sour and carbonic acid taste of carbon dioxide produced during the fermentation process. So, carbon dioxide injection was tried to raise carbonic acid taste of kimchi stored in the airtight container. First, carbon dioxide injection times of a given gas supply system were determined experimentally to attain initial concentration of 80% for different solid/liquid ratios. Since carbon dioxide is dissolved in kimchi to decrease its concentration during storage, periodical carbon dioxide injection conditions were needed and determined to keep the $CO_2$ concentration above 70%. For the initial flushing to 80% $CO_2$ concentration in model system filled with water, the injection time ranged from 40 to 89 seconds for free volumes of 2-8 L. $CO_2$ injection conditions for the under-ripened storage at $10^{\circ}C$ consisted of longer time at more frequent cycles for watery kimchi than for Chinese cabbage kimchi. At $0^{\circ}C$ of subsequent ripened stage storage of watery kimchi, the periodical injection at 3 hour interval was required because of continuous dissolution of carbon dioxide. However, Chinese cabbage kimchi did not require subsequent $CO_2$ injection during the ripened state storage and needed only flushing to 80% $CO_2$ at time of the container opening and closing. These results can be used as basic information for the programmed control of $CO_2$ injection in the kimchi container system.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.5
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• pp.596-605
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• 2003

Statement of problem : IPS Empress2 system was developed and used in prosthodontic treatment, but the cost of ingot is expensive for wide application. Purpose : This study was to investigate the possibility on recycling of IPS Empress 2 ceramic for wide application of IPS Empress 2 ceramic in prosthodontic treatment. Material and Method : 1st, 2nd and 3rd pressed disc-shaped($10{\times}1.5mm$) IPS Empress 2 specimens were made with IPS Empress ingot(200, Ivoclar, Liechtenstein) and pressing furnace(IPS Empress EP 500, Ivoclar, Liechtenstein). Vicker's surface hardness and fracture toughness, acid resistance, and pressing accuracy of IPS Empress 2 ceramic were measured and analyzed. Surface hardness was measured by microhardness tester(MTX 70. Matsuzawa, Japan), before and after surface treatment with 0.5% hydrofluoric acid and carbonic acid(Coca cola) for evaluation of acid resistance. Results : The surface hardness of 1st pressed specimen was the higher(5.11 GPa) than those of 2nd pressed(4.89 GPa) and 3rd pressed specimen(4.86 GPa), and the fracture toughness of 1st pressed ($1.58MPam^{1/2}$) and 2nd pressed specimen($1.51MPam^{1/2}$) were higher than that of 3rd pressed specimen($1.39MPam^{1/2}$). The changes of surface hardness of 1st, 2nd, and 3rd pressed specimens after treatment with fluoric acid were 0.17, 0.06, 0.05 (GPa) respectively, and those of 1st, 2nd, and 3rd pressed specimens after treatment with carbonic acid were 0.07, 0.00, 0.05(MPa) respectively. The pressing accuracy of 1st,2nd and 3rd specimen were 77.22%, 85.681%, and 75.05%. The pressing accuracy of 2nd pressed specimen was higher than that of the 3rd specimen. Conclusion : The changes of physical properties according to recycling of IPS Empress 2 from this study were insignificant. Therefore the possibility of recycling of IPS Empress 2 can be suggested from the results.

• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.169-187
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• 2002

The effects of important parameters such as reaction time and pH on the Fenton's process were evaluated using a batch reactor. It was proven that organic materials and heavy metals in leachate could be successfully removed by Fenton's reagent. Favorable operation conditions were investigated. It was observed that the reaction between ferrous iron and hydrogen peroxide with the production of hydroxyl radical was almost complete in 10 minutes. That is, the oxidation of organic materials by Fenton's reagent was so fast that it was complete in 30 minutes with batch experiments. With the formation of carbonic acid, pH of the batch reactor decreased to favorable acidic conditions without acid addition. The oxidation of organic materials in the leachate showed a pH dependence and was most efficient in the pH range of 2-3.

• Journal of Microbiology and Biotechnology
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• v.20 no.10
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• pp.1424-1429
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• 2010

A poly(${\gamma}$-glutamic acid) (${\gamma}$PGA)-cholesterol conjugate was synthesized and its properties were then evaluated. The conjugate exhibited an amphiphilic nature derived from the hydrophilic ${\gamma}$PGA backbone and the hydrophobic cholesterol side chain. The conjugate spontaneously formed nanoparticles, becoming an aqueous solution when at low concentrations, and at high concentrations the result was the formation of a physical gel. By utilizing the self-aggregating properties of the conjugate in water, an artificial chaperone was developed. A complex of protein, with the nanoparticles of the conjugate, was formed and the protein was released upon the dissociation of the nanoparticles through the addition of ${\beta}$-cyclodextrin. For denatured carbonic anhydrase, the activity was recovered in the artificial chaperone of the nanoparticle conjugate.

• 한국신재생에너지학회:학술대회논문집
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• 2006.11a
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• pp.230-233
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• 2006

Small hydropower, one of renewable energies, is the clean energy which emits no carbonic acid gas. It has noting to do with global warming. It is a useful resource to contribute to the dispersion of power. Because of ballooning oil prices, the need for small hydropower is increasing. Recently small hydropower development using dams, small rivers, reservoirs, water pipes, sewage treatment plants and cool ing water of thermal power plants is conducting. By suggesting the strategy of the enlargement revitalization of small hydropower development, we hope to waken the people's interest in the small hydropower

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.18 no.2
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• pp.113-117
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• 2007

Although the prevalence of laryngopharyngeal reflux (LPR) is presumed to be very high, basic researches on LPR have not been active so far. This is a review of present status and prospect of researches on LPR to help readers' understanding of current trend on LPR research. In vitro and in vivo researches on acid/pepsin, intercellular junctions, bile juice, carbonic anhydrase, cytokines, and Helicobacter pylori were discussed. Considering that quality of life is getting more important in accordance with longer life span and that a fair proportion of LPR patients do not respond to conventional therapy, researches on pathogenesis and pathophysiology of treatment measures are necessary and it is anticipated for more and more researchers to concern themselves in basic research on LPR in the future.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.2
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• pp.141-148
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• 2003

Concrete surface is a part that resists chiefly to carbonation by carbonic acid gas, affluence of rainwater and air, deterioration by freezing thawing, salt damage by seawater, and other chemical erosion etc. Therefore, this research analyzed physical characteristic and durable characteristic of concrete eliminated glut water and bubble of concrete surface using CON-SILK that is permeated with dehydration. As a research result, concrete using CON-SILK was improved, in comparison with concrete using general formwork, in physical performance and durability of concrete, as surface hardness, carbonation resistivity, and salt content permeation resistivity etc. Therefore, we could know that it is effective to use CON-SILK in performance elevation of concrete surface.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.35-40
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• 1992

Results of an experimental study on the manufacture, the workability and mechanical properties of steel fiber reinforced polyester resin composites utilizing industrial waste products are presented in this paper. The fly ash polyester resin composites using steel fiber, fly ash and calcium carbonic acid (CaCo3), unsaturated polyester resin, styrene monomer, cobalt octate and methyl ethyl ketone peroxide, fine and coarse aggregates are prepared with various filler~binder rations, binder rates and mixing conditions. As a test results, the workability of steel fiber reinforced polyester resin composites are considerably dropped with increasing fly ash-binder ratio and steel fiber volume. And compressive, flexural strength and bending toughness of the composites are remarkably improved with augmenting fiber contents.

• Korean Journal of Pharmacognosy
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• v.6 no.2
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• pp.101-110
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• 1975

In this study attempts were made to explore effects of the water and alcohol extracts of Junci Herba on the renal function of dogs. The water extract (in a dose 15 mg/kg, i.v.) and alcohol extract (in a dose 1.5 mg/kg, i.v.) elicited a diuretic response and produced a marked diuresis during bicarbonate infusion whereas no diuresis ensues during infusion of hydrochloric acid. The ratios of potassium and sodium excreted in urine $(K^+/Na^+)$, pH of urine, Cosm (osmolar clearance) and $C_{H_2O}$ (free water clearance) increased but hemodynamic states changed little with both extracts. All the observed facts can be best explained on the assumption that Junci Herba inhibits the carbonic anhydrase in the tubule. Thus it produces the effect by increasing urinary potassium and sodium.

• Corrosion Science and Technology
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• v.7 no.6
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• pp.350-361
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• 2008

Canada's oil sands contain one of the largest reserves of oil in the world. According to recent estimates, there are nearly 180 billion barrels of oil in the Canadian oil sands trapped in a complex mixture of sand, water and clay. More than 40 companies have been currently operating or developing oil sands facilities since the first production in 1967. The process of oil sands upgrading is similar with down stream refinery, but the corrosion environment in upgrading refinery is often more severe than in the refinery because of high chlorides, mineral contents, carbonic acid, heavy viscosity and fouling, higher naphthenic acid [$NA-R(CH_{2})nCOOH$], and greater sulfur contents. Naphthenic acid corrosion (NAC) which is one of the most critical corrosion issues in up & downstream refinery plants was observed for the first time in 1920's in refinery distillation processes of Rumania, Azerbaizan (Baku), Venezuela, and California. As a first API report, the 11th annual meeting stated sources and mechanism of NAC in early 1930's. API has been developing the risk base standards, such as API RP580, 571, and Publication 581 which are based on the worst NAC damage in the world since 2000. Nevertheless not only the NAC phenomena and control in Canadian sands oil process are not much widely known but also there are still no engineering guidances for the Canadian sands oil in API standards. This paper will give NAC phenomina and materials selection guidance against NA environment in Canadian oil sands upgrading processes.