• 제목/요약/키워드: distilled water

검색결과 2,421건 처리시간 0.031초

DPPC-ODA-asparagine 리포솜의 포도당 친화도 및 콜레스테롤 첨가에 따른 안정성 측정 (Glucose Binging Affinity of DPPC-ODA-asparagine and Stability of Liposomes Adding Cholesterol)

  • 문제영;이기영;김진철;박기남
    • KSBB Journal
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    • 제16권2호
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    • pp.170-173
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    • 2001
  • Liposome-amino acid conjugates were prepared using dipalmitolyphosphatidylcholine(DPPC) and hydrophobically modified asparagine. A microdialyzer was used to measure glucose diffusion. The glucose binding affinity of DPPC-ODA-asparagine liposomes higher than that of DPPC liposomes and distilled water. The size of DPPC-ODA-asparagine was approximately 75-150 nm. Cholesterol increased the stability of liposomes, and reduced the size of liposome particles.

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황련에 의한 Tencel직물의 염색 (Dyeing of Tencel with Coptis chinensis Franch)

  • 배상경
    • 한국염색가공학회지
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    • 제12권5호
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    • pp.288-294
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    • 2000
  • The dyeing of Tencel fabric with Coptis chinensis Franch was studied. The colorant was extracted with distilled water under various concentrations of dyestuff, times, mordants. UV-VIS spectra were obtained to find the maximum wavelength and absorbance of colorant. Tencel fabric was dyed with different mordants in pre and post-mordanting methods. Maximum wavelength of spectrum was 343 nm, and K/S value of pre-mordant was higher than post-mordant. Aluminium and stannic mordants changed color from yellow to blue-greenish and red-bluish. Colorfastnesses of light, and washing were low grade, but that of perspiration was increased.

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수종(數種)의 한약재(韓藥材) 추출물(抽出物)의 항산화능(抗酸化能)과 혈전용해능(血栓溶解能) (Antioxidative and Fibrinolytic Activities of Several Medicinal Plant Extracts)

  • 주은영;박찬성
    • 대한본초학회지
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    • 제25권3호
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    • pp.53-60
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    • 2010
  • Objectives : This study was conducted to evaluate the antioxidative and fibrinolytic activity of the water and ethanol extracts from medicinal plants. Methods : Five kinds of medicinal plants(Carthami Flos, Glycyrrhizae Radix, Schisandrae Fructus, Atractylodes Rhizoma, Shiitake mushiroom) were extracted with distilled water and 70% ethanol, and the extracts were tested for their antioxidative and fibrilytic activities. Results : The highest polyphenol contents of the water and ethanol extracts from medicinal plants were 812.52 mg and 685.44 mg per 100 g of Carthamus tinctorius and Schizandra chinensis, respectively. The electron donating abilities (EDA) of the water extracts from all medicinal plants except Lentinus edodes were about 90% at 1,000 ppm and ethanol extracts were higher than those of water extracts. The highest SOD-like activity and nitrite scavenging abilities (NSA) were both of water and ethanol extracts from Schizandra chinensis. Five kinds of medicinal plants had fibrinolytoc activity and the highest activities were water and ethanol extracts from Glycyrrhiza uralensis. Conclusion : These results suggest that the medicinal plants can be used as natural antioxidant to prevent oxidative damage in normal cells probably because of their antioxidative and fibrinolytic activities.

이온 마이그레이션 발생에 대한 수분온도의 영향 (Effect of Water Temperature on Generation of Ion Migration)

  • 이덕보;김정현;강수근;김상도;장석원;임재훈;유동수
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제5권2호
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    • pp.261-272
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    • 2005
  • In evaluation of electronic reliability on the PCB(Printed Circuit Board), electrochemical migration is one of main test objects. The phenomenon of electrochemical migration occurs In the environment of the high humidity and the high temperature under bias through a continuous aqueous electrolyte. In this paper, the generating mechanism of electrochemical migration is investigated by using water droll acceleration test under various waters. The waters used in the water drop test are city water, distilled water and ionic water. It found that the generated velocity of electrochemical migration depended on the temperature of water and the electrolyte quantity which included in the various waters.

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Corrosive Wear of Alloy 690 Tubes in Alkaline Water

  • Hong, Seung Mo;Jang, Changheui;Kim, In Sup
    • Corrosion Science and Technology
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    • 제8권3호
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    • pp.126-131
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    • 2009
  • The interaction between wear and corrosion can significantly increase total material losses in water chemistry environment. The corrosive wear tests of a PWR steam generator tube material (Alloy 690) against the anti vibration bar material (409 SS) were performed at room temperature. The tests were performed in alkaline water chemistry conditions. NaOH solution was selected for test condition to investigate the corrosive wear effect of steam generator tube material in alkaline pH condition without other factors. The flow induced vibration can caused tube damage and the corrosion can be occurred by water chemistry. The test results showed that, in the alkaline solution at pH 13.9, the corrosion current density was increased about ten times than that in the distilled water. And wear rate at pH 13.9 was increased about ten times from that at neutral condition. However, the wear rate was decreased with time. The decrease would be attributed to the change in roughness of specimen or sub-layer of the worn surface with time. From microstructure observation, severe abrasive shape and several wear debris were found. From those results, it could infer that the oxide film on Alloy 690 changed to easily breakable one in the alkaline water, and then abrasion with corrosion became the main wear mechanism.

The Development of Slag Based Materials for the Reformation of Soft Ground

  • Byeon, Tae-Bong;Kim, Hyung-Suek;Han, Ki-Hyun
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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    • pp.537-541
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    • 2001
  • For the development of reformation material of soft ground using the LD slag, the relation to the particle condition of LD slag and the pH behavior of slag dissolution water, extraction properties of slag, and origination of white water were investigated. When the LD slag is mixed with sea water, the pH of solution ranged between 9.47 and 10.0. On the other hand, when mixed with distilled water, the pH was about 10.4 to 12.1. For the as-received slag and the aged slag in sea water, a pH of 11.5 to 12.0 was observed when the particle size was less than 0.5mm. For the reoxidized slag in seawater, the pH of the solution was lower than 9.5 when the particle size was bigger than 0.075mm. For the aged slag and reoxidized slag, the pH of the solution remained constant when the addition ratio of sea water to the slag was higher than 500 times. The main elements dissolved from the slag were Ca and Mg ions. When the pH went over 9.0, the white water started to font which was caused by the CaCO$_3$and Mg(OH)$_2$.

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이온 마이그레이션 발생에 대한 수분온도의 영향 (Effect of Water Temperature on Generation of Ion Migration)

  • 이덕보;김정현;강수근;김상도;장석원;임재훈;유동수
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2005년도 학술발표대회 논문집
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    • pp.339-348
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    • 2005
  • In evaluation of electronic reliability on the PCB(Printed Circuit Board),electrochemical migration is one of main test objects. The phenomenon of electrochemical migration occurs In the environment of the high humidity and the high temperature under bias through a continuous aqueous electrolyte. In this paper, the generating mechanism of electrochemical migration is investigated by using water drop acceleration test under various waters. The waters used in the water drop test are city water, distilled water and ionic water. It found that the generated velocity o of electrochemical migration depended on the temperature of water and the electrolyte quantity which included in the various waters.

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초음파를 조사(照射)한 유기화합물 수용액 속에서의 과산화수소 생성량의 측정 (Measurement of the Quantity of Hydrogen Peroxide Produced in the Ultrasound-irradiated Aqueous Solution of Organic Compounds)

  • 모세영;장홍기;이경재;장건익;손종렬
    • 대한환경공학회지
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    • 제22권1호
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    • pp.61-71
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    • 2000
  • 수용액 속에 강력초음파를 조사(照射)하면 공동화기포 (cavitation bubble) 속의 매우 높은 온도의 열에 의해 수증기가 해리되어 OH (hydroxyl radical) 과 H (hydrogen radical) 이 생성되고 그것들이 수용액 속에 함유되어 있는 물질들을 산화 또는 환원시켜 분해시키며, 한편으로는 과산화수소를 생성한다. 따라서 생성된 과산화수소의 양과 유기물질의 초음파 분해반응메카니즘과는 상관관계가 있을 것임을 예측할 수 있으며, 이러한 예측을 확인하기 위해 공기로 포화시킨 증류수와 그 증류수에 각각 TCE, Benzene, 그리고 2,4-DCP 등 세 가지 유기물질들을 용해시킨 수용액으로부터 생성된 과산화수소의 양을 측정하고 그 결과를 분석하였다. 그 결과, 생성된 과산화수소의 양은 증류수>TCE수용액>2,4-DCP수용액 >benzene수용액의 순으로 많고 유기물질의 농도가 낮을수록 적어 TCE는 높은 온도의 수용액에서는 고온과 고압인 공동화기포내와 그 공동화기포가 파열될 때 그 주위에서 직접 열분해되고 저농도의 수용액에서는 라디칼반응에 의해 분해되며, 벤젠과 2,4-DCP는 열분해 및 라디칼반응에 의해 분해된다고 제안된 초음파 분해반응메카니즘과 일치함을 나타내었다. 사용한 실험변수인 초음파의 주파수와 음향출력, 그리고 시료물질의 농도 등의 영향은 주파수가 높고 음향출력이 낮을수록 과산화수소의 생성량이 적어 수중에 강력초음파를 조사(照射)하였을 때의 에너지원인 공동화와 이들 변수와의 관계에 대한 초음파이론과 일치하였다.

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수용성 키토산분해물질을 침지액으로 이용한 두부의 저장성 증대 (The Extension of Tofu Shelf-Life with Water-Soluble Degraded Chitosan as Immersion Solution)

  • 전기환;김병용;손태일;함영태
    • 한국식품과학회지
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    • 제29권3호
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    • pp.476-481
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    • 1997
  • 두부의 저장성에 미치는 수용성 키토산 분해물질의 영향을 알아 보기 위해 두부침지액으로 일반 시중 두부공장에서 사용하는 수돗물, 멸균증류수, 0.5% 키토산 분해물질, 0.5% fumaric acid, 0.5% lactic acid를 사용하여 $4^{\circ}C$에서 냉장저장하면서 pH와 탁도, 그리고 미생물상의 변화를 관찰하였다. 수용성 키토산 분해물질을 첨가한 침지액의 경우 총균수가 21일 저장시 $10^{7}\;CFU/mL$에 달해 다른 침지액에 비해 7일에서 14일의 저장기간 연장을 관찰할 수 있었다. 특히 초기 오염 미생물의 lag phase가 다른 군에 비해 상당히 길어진 것을 관찰할 수 있었다. Yeast와 mold, 그리고 E. coli의 경우도 시간이 경과됨에 따라 증가하였으며, 0.5% 키토산 분해물질 첨가 침지액의 경우가 다른 침지액의 경우보다 증가율이 적음을 알 수 있었다. 이는 수용성 키토산 분해물질의 항균효과를 잘 보여주고 있다. 초기 pH는 0.5% fumaric acid와 lactic acid의 경우 pH 4.68과 pH 5.12로 상당히 낮았으며, 수돗물과 멸균증류수, 0.5% 키토산 분해물질 첨가 침지액에서는 pH 7.2로 비슷하였고, 저장 초기에 약간 감소하다가 서서히 증가하는 경향을 보였다. 탁도의 변화는 미생물상의 변화와 연관시켜 두부가 부패된 것으로 간주되는 총균수 $10^{7}\;CFU/mL$이상에서 0.2를 초과해 탁도가 두부부패정도를 파악하는 한 척도가 될 수 있다고 판단된다. 상기 결과로부터 항균성을 가지는 수용성 키토산 분해물질을 첨가한 두부 침지액의 개발은 두부의 저장성 향상에 크게 기여할 것으로 사료된다.

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수분과 계면활성제가 밀전분의 호화와 노화에 미치는 영향 (Influence of Water and Surfactants on Wheat Starch Gelatinization and Retrogradation)

  • 신말식
    • 한국식품과학회지
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    • 제23권1호
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    • pp.116-121
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    • 1991
  • 밀전분의 호화와 노화에 수분함량과 sodium stearoyl-2-lactylate(SSL), sucrose ester(SE), monoglyceride(Dimodan) 같은 surfactant의 효과를 differential scanning calorimetry를 이용하여 조사하였다. 전분의 호화양상은 수분함량에 따라 다르고 수분함량이 30% 이하이면 호화가 일어나지 못하였다. 호화개시 온도는 $59{\sim}60^{\circ}C$이었으며, 노화개시 온도는 $50{\sim}55^{\circ}C$이었다. 노화된 전분의 엔탈피는 수분함량이 $40{\sim}50%$일 때 가장 컸다. Surfactant를 첨가하면 호화온도는 약간 높아졌고, amylose-lipid complex의 엔탈피는 증가하였다. Surfactant를 첨가한 전분은 저장에 따라 노화가 늦게 진행되었으나 amylose-lipid complex의 변화는 거의 없었다.

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