• 동아시아식생활학회지
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• 제5권3호
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• pp.287-298
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• 1995

This study was undertaken to examine the effect of salting in 10% salt solution added 2% calcium chloride on the kimchi fermentation. The addition of calcium chloride extended edible periods of the Kimchi to 4~5 days and increased relatively the hardness of Chinese Cabbage. In the addition of calcium chloride, the activities of amylase and $\beta$ -galactosidase were not high during all periods fermentation. Polygalacturonase and protease activities were low 2~21%, 2~26% all periods fermentation, respectively. There were significant correlations between the delay of ripeness and decreasing enzyme activation. The amount of free amino acid by the treatment with calcium chloride was decreased of 10~16% at the late of fermentation than that of control. the treatment with calcium chloride of the Kimchi was increased hardness, but decreased cohesiveness and gumminess was during all periods fermentation. the adhesiveness was increased at the early of fermentation but decreased at the late of fermentation.

• 한국식품저장유통학회지
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• 제19권6호
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• pp.813-817
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• 2012

신선절단 '후지' 사과의 갈변도에 화학물질(ascorbic acid, cystein, sodium chloride, magnesium chloride, calcium chloride, histidine: 1% 용액), 한약재(갈근, 당귀, 산약, 오약, 천궁, 황기: 1% 추출액), 가열(절단과실과 원형과실, $40-60^{\circ}C$ 증류수) 및 코팅(albumin, dextrin, sucrose poly ester, whole soy flour: 0.5-4% 용액) 처리가 미치는 영향을 조사하였다. 각 처리방법별 신선절단 사과의 갈변도는 1% calcium chloride 용액 처리, 황기 추출물 처리, 3% dextrin과 1% whole soy flour 코팅 처리에 의해 가장 낮은 수준을 보였다. 가열처리의 갈변도는 절단과실 처리시에는 $50^{\circ}C$에서, 원형과실 처리시에는 $45^{\circ}C$에서 각각 처리한 시료에서 가장 낮은 수준을 보였다. 이로써 신선절단 사과의 갈변에 대한 한약재 추출물, 가열 및 코팅 처리의 억제 효과와 조건이 확인되었고, 이러한 방법은 화학물질을 부분적으로 대체할 수 있을 것으로 판단된다.

• 공업화학
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• 제5권4호
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• pp.646-656
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• 1994

Pyridine 촉매 존재하에서 고리형 올레핀류의 오존 산화 반응에 의해 ${\omega}$-formyl carboxylic acid를 합성하고 합성시 온도와 용매가 생성물의 수율에 미치는 영향을 고찰하였다. 사용한 시클로올레핀의 종류에 관계없이 반응온도가 증가할수록 ${\alpha}$, ${\omega}$-dicarboxylic acid의 수율은 증가하는데 비하여 ${\alpha}$, ${\omega}$-dialdehyde은 감소하였다. 그리고 용매의 극성이 클수록 ${\omega}$-formylcarboxylic acid의 수율은 증가하였으며 원하지 않는 polymeric ozonide의 수율은 감소하였다. 반응온도 $0^{\circ}C$와 methylene chloride용매를 사용할 경우 cyclohexene, cyclooctene그리고 cyclododecene의 오존 산화 반응으로부터 생성된 ${\omega}$-formyl carboxylic acid의 수율은 각각 59.30%, 55.20% 그리고 36.72%이었다.

• 한국식품과학회지
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• 제21권3호
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• pp.370-374
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• 1989

소금농도와 저장기간이 깍두기의 특성에 미치는 영향을 조사하기 위하여 깍두기의 관능적 특성, pH 및 적정산도를 측정하였으며 capillary gas chromatography로 비휘발성 유기산을 정성 및 정량 분석하여 비교하였다. 소금농도와 저장기간은 깍두기의 질긴 정도를 제외한 모든 관능적 특성에 영향을 주어 소금농도 2%군은 1%와 3%군에 비해 단단한 정도와 아삭아삭한 정도가 낮고 신맛이 강하였으며, 저장 8일군은 4일군보다 신맛과 이취는 강하나 단단한 정도와 아삭아삭한 정도는 낮았다. 저장기간이 증가할수록 pH는 감소하고 산도는 증가하였으며, 이 현상은 특히 2%군에서 두드러지게 나타났다. 깍두기에서 추출한 비휘발성 유기산으로는 lactic acid, succinic acid 및 citric acid가 대부분이었으며 소금농도 2%군은 다른 실험군들에 비해 유기산 생성량이 많았다. 이상의 결과에서 볼 때 소금농도 2%는 1%와 3%에 비해 깍두기의 연부를 억제하고 산의 생성을 감소시키는 숙성 억제효과가 낮았으며 깍두기의 신맛은 pH보다는 산도와 비휘발성 유기산 함량에 더 관련이 많았다.

• 한국산업보건학회지
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• 제31권3호
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• pp.255-265
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• 2021

Objectives: The purpose of this study is to analyze the exposure characteristics of inorganic acids. Methods: We analyzed exposure data (n = 363,146) for six inorganic acids (hydrogen fluoride, hydrogen bromide, hydrogen chloride, phosphoric acid, nitric acid, and sulfuric acid) collected between 2017 and 2019 in South Korea. Measurement characteristics and exposure levels (ELs) were analyzed by inorganic acid, industry category, enterprise size, and measurement year. Results: Measurement percentage dominated in time-weighted average (TWA, 91%) compared to short term exposure limit (STEL) and Ceiling. Most of the measurements (79.7%) were collected from the manufacturing category of industry. Medians of ELs were mostly low (≤3% of the threshold limit), with the exception of sulfuric acid (4.6% of TWA and 10.5% of STEL). The percentages of exceeding 1% of the occupational exposure limits (OELs) in TWA were relatively high for sulfuric acid (35.8%) and hydrogen chloride (16.5%) compared to the other acids (4.2%-6.6%). In addition, the percentages of exceeding 1% of OELs in STEL or Ceiling were higher for sulfuric acid (22.9%), hydrogen chloride (12.3%), and nitric acid (8.2%) compared to the other acids (1.2%-1.9%). The small-sized enterprises showed higher ELs in TWA; contrarily, the large-sized enterprises had higher ELs in STEL or Ceiling. Conclusions: The measurement characteristics and ELs identified in this study could be useful for establishing safety and health policies for inorganic acids.

• 약학회지
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• 제30권6호
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• pp.294-300
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• 1986

New antibiotics having moieties of penicillanic acid, cephalosporanic acid and ampicillin on both ends of the central polyalkylene were synthesized by reacting 6-aminopenicillanic acid (6-APAl), 7-amino cephalosporanic acid (7-ACA) and ampicillin with hexamethylene diisocyanate and sebacoyl chloride, respecetively. Antibiacterial activities of the compounds were also investigated.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2918-2922
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• 2010

We demonstrate a facile route to synthesize silver chloride nanocubes and derivative nanomaterials. For the synthesis of silver chloride nanocubes, silver nitrate and hydrochloric acid were used as precursors in ethylene glycol, and poly (vinyl pyrrolidone) as a surfactant. Molar ratio of the two precursors greatly influenced the morphology and composition of the final products. As-synthesized silver chloride nanocubes showed size-dependent optical properties in the visible region of light, which is likely due to a small amount of silver clusters formed on the surface of silver chloride nanocubes. Moreover, we show for the first time that simple reduction of silver chloride nanocubes with different reducing reagents leads to the formation of delicate nanostructures such as cube-shaped silver-nanoparticle aggregates, and silver chloride nanocubes with truncated corners and with silver-nanograin decorated corners. Additionally, we quantitatively investigated for the first time the evolution of silver chloride nanocubes to silver chloride nanocubes decorated with silver nanoparticles upon exposure to e-beam. Our novel and facile synthesis of silver chloride related nanoparticles with delicately controlled morphologies could be an important basis for fabricating efficient photocatalysts and antibacterial materials.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권3호
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• pp.30-36
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• 2003

본 연구에서는 미셀 한외여과(Micellar-enhanced ultrafiltration, MEUF)공정으로 질산성 질소와 인산을 동시에 제거할 때 휴믹산이 공정에 미치는 영향을 살펴보았다. 계면활성제/오염물의 몰 비가 1인 경우, 질산성 질소는 미셀 표면에 휴믹산과 경쟁적으로 결합을 하기 때문에 그 제거율이 50%로 감소하지만, 몰 비 3 이상의 계면활성제를 첨가하였을 때에는 80% 이상의 제거율을 유지하였다. 반면 인산의 경우에는, 몰 비 1 이상의 CPC 농도에서 질산성 질소와는 달리 휴믹산이 존재하지 않는 경우와 비슷한 수준인 80％ 이상의 제거율을 보였으며, 이때 CPC와 휴믹산의 제거율은 거의 99％ 이상 이었다. 또한 100 ppm농도의 휴믹산은 MEUF공정에서 플럭스 감소에 영향을 미치지 않고 오히려 조금 증가시켰으며, 이는 막에 흡착한 휴믹산이 막의 친수성을 증가시켜 투과율을 높이기 때문인 것으로 판단된다. 이를 통해 휴믹산은 질산성 질소 및 인산을 동시 제거하는 MEUF 공정에서 제거효율을 저하시키지 않음을 확인하였다.

• 한국수산과학회지
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• 제51권6호
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• pp.682-687
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• 2018

We investigated the effects of a highly saline solution (HS) containing hypochlorous acid, calcium chloride ($CaCl_2$), and phosphoric acid ($H_3PO_4$) on cell death and growth rate of laver Porphyra yezoensis and green laver Ulva intestinalis. Cell death rates of laver treated with HS and HS plus hypochlorous acid (HS + HOCl) in the harvesting stage were less than 0.5%, and there were no significant differences between the HS and HS + HOCl treatments. However, cell death of green laver treated with HS + HOCl in the harvesting stage was greater than 81.2%. These results indicate that the addition of HOCl is highly effective to eradicate noxious green laver without causing damage to laver. The addition of HOCl and $H_3PO_4$ to HS did not increase the area or weight of laver blades. A combination treatment of $CaCl_2$ and HS, however, significantly increased the area and weight of laver lades compared to controls (P<0.05).

• The Korean Journal of Physiology
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• 제24권1호
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• pp.123-129
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• 1990

A comparative study of acid-base balance has been made between acidemia-induced hyperkalemia and hyperkalemia-induced acidemia. A group of rabbits was infused 0.1 N hydrochloric acid solution and metabolic acidosis was induced. Another group was administered 20 mM potassium chloride solution and hyperkalemia was induced. The third group was infused 0.1 N hydrochloric acid and 20 mM potassium chloride solution, simultaneously. Acid-base data and plasma potassium ion concentration were monitored every thirty minutes in these three groups of rabbits. Following results were obtained: 1 ) Along with the infusion of hydrochloric acid, acute metabolic acidosis was induced in the rabbits. Plasma bicarbonate ion concentration decreased primarily in this group. As a respiratory compensation, there was a tendency of reduction of arterial $Pco_{2}$. The alteration of data became larger along with the amount of administration and the time elapsed. However, hyperkalemia was not so severe compared with the second group. 2) In potassium chloride infused group, plasma potassium ion concentration increased along with the time elapsed and the amount of infusion. And the alteration of acid-base data was parrallel to the level of potassium ion concentration, above all depression of pH was prominent. 3) Above data suggest that when acute metabolic acidosis was induced, exchange of intracellular potassium ion with extracellular hydrogen ion seems significant for the regulation of extracellular acid-base balance. And when hyperkalemia was induced with the infusion of potassium chloride solution, the exchange of intracellular hydrogen ion with extracellular potassium ion also seems significant for the regulation of extracellular potassium balance. 4) In the group of rabbits infused hydrochloric acid and potassium simultaneously, disturbances of acid-base balance and potassium balance were much more severe than two other groups. In these mixed disturbances, the process of compensatory mechanism might be inhibited and one disturbance might aggregate each other. 5) Through above data it has been postulated that in acid-base disturbance potassium balance can be sacrificed as a compensatory mechanism, and vice versa in disturbance of potassium balance. And our data also suggest that hydrogen ion and potassium ion are compensatory pair, one another.