• Title/Summary/Keyword: citric acid

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SCANNING ELECTRON-MICROSCOPIC STUDY OF THE EFFECT OF CITRIC ACID AND TETRACYCLINE HCL CONDITIONING ON DISEASED ROOT SURFACE (구연산과 염산트라싸이클린이 치근면 탈회에 미치는 효과에 대한 주사전자현미경적 연구)

  • Kim, Young;Kwon, Young-Hyuk;Lee, Man-Sup
    • Journal of Periodontal and Implant Science
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    • v.25 no.1
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    • pp.24-34
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    • 1995
  • The purpose of this study was to compare effects of demineralization of citric acid and tetracycline HCI on periodontally involved root surface. Twelve periodontally involved single rooted teeth were used. After scaling and root planing, root conditioning with citric acid and tetracycline HCI were carried and the teeth were processed scanning electron microscopic observation.The results were as follows: The scaled root surface was covered by much debris and calculus. The effect of demineralization of citric acid and tetracycline HCI was more reduced on scaling group than root planing group, because of hypermineralization of cementum surface and demineralization effect on root surface of tetracycline HCI showed tendency to reduction. The root planed group displayed more smooth root surface than scaling group, the surface was covered by smear layer, thus no exposure of dentinal tubule opening and collagen fiber, especially after root planing, citric acid and tetracycline HCl treated group showed exposure of dentinal tubule and collagen fiber, thus it was thought that new connective tissue attachment could be acquired.

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Studies on the Citric Acid Fermentation (Part 2) The Citric Acid Fermentation by Asp. niger, as the Substrate of Local Commercial Glucose (구연산 발효에 관한 연구 (제 2 보) 국산 포도당을 기질로하고 Asp. niger에 의한 발효)

  • 이상선;박무영
    • Microbiology and Biotechnology Letters
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    • v.6 no.4
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    • pp.167-171
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    • 1978
  • When Asp. niger was shaked at 3$0^{\circ}C$ in 500 mι Erlenmeyer flask with 50 ml of the medium containing 14% of Korean local commercial glucose brand, 0.45% of peptone, and mineral, the citric acid was produced at the level of 37~43 gram per liter in 8 days, and the citric acid production at medium containing X glucose brand was better than that containing Y glucose brand. When the contaminated minerals were removed from the local glucose by Ambelite-IR 120 and peptone by potassium ferrocyanide followed by readjustment of ferric ion content in the medium to 10 mg per liter, the citric acid formation reached 53 gram per liter, a production level of three times higher than that with the original Sakaguchi's medium. The further physiological studies and the mutation of isolated Asp. niger will be needed.

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Optimization of Garlic Jam Making by Response Surface Methodology (반응표면분석에 의한 마늘잼 제조조건의 최적화)

  • Sim, Gi-Hyeon;Ju, Na-Mi;Han, Yeong-Sil
    • Journal of the Korean Dietetic Association
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    • v.12 no.1
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    • pp.32-43
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    • 2006
  • The purpose of this study is to find out the optimal mixing ratios of three different amounts of pectin, sugar and citric acid for preparation of garlic jam through response surface methodology(RSM) based on the sweetness, pH, color, sensory and texture test. As the sucrose content increased, the sweetness, cohesiveness, color, flavor, gloss and overall palatability of garlic jam tended to be high and the lightness tended to be low. As the pectin content increased, the adhesiveness of garlic jam tended to increase. As the citric acid content increased, the overall palatability of garlic jam tended to be high and the pH tended to be low. The Pectin levels were included 1.8-2.1g, sucrose levels were included 325-342g and citric acid levels were 5.8-6.1g. The optimal mixing ratios of a pectin, sugar and citric acid for manufacturing the best quality of garlic jam were 2.0g, 334g and 6.0g, respectively.

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Preparation and Magnetic Properties of Acicular Ba-Ferrite Powder

  • Lee, Hak-Dong;Nam, Joong-Hee;Oh, Jae-Hee
    • Journal of Magnetics
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    • v.5 no.2
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    • pp.40-43
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    • 2000
  • Acicular $\alpha-FeOOH\; and\; Ba(OH)_2\cdot8H_2O$ are starting materials in this study. This paper presents the characteristics of the contents of citric acid and heating condition for preparing acicular barium ferrite powder. They control particle shape, crystalline phase, magnetic properties of acicular barium ferrite powder So the effects of the contents of citric acid and heating condition are studied. The experimental condition for starting materials were 800~1000$\circ C$ in firing and 0~40 wt% citric acid, respectively, Ba-ferrite particles fired at the range of 800 $\circ C$to 900 $\circ C$ were maintained as acicular particle shape, but there were mixed particles of acicular and round shape after fired at 950 $\circ C$. Ba-ferrite powder of the single phase was obtained in firing at 900~1000$\circ C$ and with 20 wt.% citric acid. There were unreacted phase of $\alpha-Fe_2O_3 \;and \; BaFe_2O_4$ phases as a second phase in case of sintering at below 850 $\circ C$. Acicular barium ferrite powder of single phase was also produced in firing at 900 $\circ C$ with 20 wt.% citric acid. The saturation magnetization of single phase of acicular $BaFe_12O_19$powder was about 51 emu/g and coercivity was about 4200 Oe.

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Isolation and Anti-thrombotic Activity of Citric acid 1,5-dimethyl ester from Gastrodia elata

  • Pyo, Mi-Kyung;Park, Kyung-Mi;YunChoi, Hye-Sook
    • Natural Product Sciences
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    • v.6 no.2
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    • pp.53-55
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    • 2000
  • In the course of continous work for the discovery of anti-thrombotic constituents from tubers of Gastrodia elata, citric acid 1,5-dimethyl ester was isolated from ethylacetate soluble fraction prepared from the methanol extract. The structure of the compound was determined by the spectroscopic data. The anti-thrombotic effect of this compound was observed with prolonging the bleeding time in thrombin-induced thrombosis model of mice.

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다종 중금속으로 오염된 사질토에 대한 EK Flushing 기술 적용

  • 김병일;한상재;이군택;김수삼
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • pp.310-313
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    • 2003
  • The precipitation of heavy metals within the region of pH jump is inevitable in the conventional electrokinetic remediation technology. This study prevents the interest species from precipitating through the injection of flushing solutions in which HCl, acetic acid, citric acid, EDTA and SDS dissolved. The cumulative flow resulted from electroosmosis appear in order of Citric acid

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Studies on the Citric Acid Fermentation (Part 1) Strain Screening and Medium Improvement (구연산 발효에 관한 연구 (제 1 보) 균주선정 및 배지 개량)

  • 이상선;박무영
    • Microbiology and Biotechnology Letters
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    • v.6 no.4
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    • pp.161-165
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    • 1978
  • Out of 11 organic acid producing strains isolated from fruits, soil, and air, one strain was selected for the study of the citric acid fermentation using Sakaguchi's medium. The organism was identified as Aspergillus niger. When Asp.niger was shaked at 3$0^{\circ}C$ in a cotton plugged 500 mι Erlenmeyer flask with 100 ml of Sakagnchi's medium containing 10% of glucose (Difco), 0.6% of peptone, and mineral, citric acid were produced at the level of 17 gram per liter in 14 days. The citric acid was also produced at the level of 35 gram per liter after the improvements of Sakaguchi's medium-the adaptation, peptone addition, aeration, methanol addition, and glucose addition.

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One-step Microwave Synthesis of Hierarchical Structured LiFePO4 using Citric Acid

  • Wu, Mihye;Choi, Sungho;Kang, Yongku;Jung, Ha-Kyun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.10
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    • pp.2901-2905
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    • 2014
  • The hierarchical-structured $LiFePO_4$ cathode materials were synthesized by one-step microwave synthesis, and their electrochemical properties were investigated. Addition of citric acid during the reaction lead to the formation of hierarchical structured $LiFePO_4$, which has both nano- and micron-characteristics advantageous for energy density and electrode fabrication. Adjusting the molar ratio of Fe to citric acid enhanced the electrochemical properties of $LiFePO_4$.

Effect of Aspergillus niger Pellets on Citric Acid Production in a Bubble Column Bioreactor

  • Kim, Seung-Hwan;Yoo, Young-Je;Kim, Eui-Yong;Kim, Min-Hong
    • Journal of Microbiology and Biotechnology
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    • v.5 no.3
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    • pp.172-176
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    • 1995
  • Citrate is mainly produced from fungi and oxygen transfer has been known as one of the important factors in citric acid production. A bubble column bioreactor was used for citrate production after pellet was initially made using a stirred bioreactor for the inoculation. The relationship between the pellet size of Aspergillus niger and the oxygen transfer was elucidated by considering morphological characteristics of the pellet. The pellet size was determined by adjusting the impeller speed in the stirred bioreactor and the optimum diameter of the pellet was observed to be 2.2 mm under the experimental conditions. Pellet was maintained quite stable in the bubble column bioreactor and production of citric acid was significantly improved by maintaining optimal pellet conditions in the bubble column bioreactor.

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Effect of Crossliking on Dimensional Stability and Dyeability of Korean Traditional Paper(Hanji) (전통한지의 형태안정성 및 염색성에 미치는 가교의 영향)

  • Park Pyong-Ki;Han Tae-Hui;Chung Yong-Sik
    • Textile Science and Engineering
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    • v.43 no.2
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    • pp.95-100
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    • 2006
  • The Hanji treated with citric acid as crosslinking agent was prepared to improve wet dimensional stability and wet-strength. To improve dyeability for direct and reactive dyes, various concentrations of chitosan were added in crosslinking process. The wet dimensional stability and wet-strength of crosslinked Hanji were improved by citric acid addition, whereas the folding endurance significantly decreased. As the concentration of citric acid increased, K/S values of the crosslinked Hanji for berberin increased, but those direct and reactive dyes decreased. However, the dye adsorption for direct dye and reactive dye were improved by chitosan addition.