• 제목/요약/키워드: fluorine

검색결과 786건 처리시간 0.028초

Ethanol 및 그 Ester의 Fluorine Derivatives중(中) ${\beta}$-체(體)의 확인(確認) 및 정량(定量)에 관(關)한 연구(硏究) (Identification and Spectrophotometric Method for Determination of the ${\beta}-Fluorine$ Compounds in Fluorides of Ethanol and its Ester)

  • 심영기;이한표;구기서;김재백
    • Journal of Pharmaceutical Investigation
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    • 제4권1_2호
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    • pp.1-6
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    • 1974
  • S-Benzylthiuronium chloride reacts with ethylene glycol, derived from hydrolysis of the fluorides, to produce a crystalline substances. Using this, the fluorides can be indentified by measuring melting point. And when the zirconium-alizarin solution reacts with ethylenefluoro hydrin or ${\beta}-fluoroethyl$ acetate, the red-violet color disappears to produce a yellow dye, which exhibits absorption maximum at about $530\;m{\mu}$ using the 250-microgram standard. Using these properties, the fluorine compounds can be determined conveniently by this method.

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Hydroxyapatite Bioceramics의 합성 및 물성에 관한 연구 (A Study on the Preparation and Properties of Hydroxyapatite Bioceramics)

  • 이석곤;고형열;이구종;최상흘
    • 한국세라믹학회지
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    • 제26권2호
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    • pp.171-178
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    • 1989
  • In order to develope hydroxyapatite ceramics which has mechanical strength as bio-implant materials and get the basic data for the study and application of biocompatibility, hydroxyapatite was synthesized at Ca/P=1.67~1.75, pH 7~11 by precipitation method. Using prepared powders, the sintered body, fluorine substituted body and the porous body was formed and their properties were investigated. The sample obtained in condition of Ca/P=1.67, pH 7 and sintering at 1,15$0^{\circ}C$ was decomposed to $\beta$-tricalcium phosphate, and co-existed with hydroxyapatite. Hydroxyapatite synthesized at pH 11 was not easily decomposed to $\beta$-tricalcium phosphate at sintering process. The substitution of a small amount of fluorine for hydroxyapatite prevented hydroxyapatite from being decompsed to $\beta$-tricalcium phosphate. Hydroxyapatite ceramics which substited of 10% fluorine was prepared at 1,15$0^{\circ}C$, and the valueof bending strength for this body were found to be 112MPa.

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AlCu 배선의 부식방지를 위한 fluorine 가스 처리연구 (A study of the fluorine treatment for the anti-corrosion after plasma etching of AlCu films)

  • 김창일;서용진;권광호;김태형;장의구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.383-386
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    • 1998
  • After etching Al-Cu alloy films using SiC1$_4$/Cl$_2$/He/CHF$_3$ plasma, a corrosion phenomenon on the metal surface has been studied with XPS (X-ray photoelectron spectroscopy) and SEM (Scanning electron microscopy). In Al-Cu alloy system, the corrosion occurs rapidly on the etched surface by residual chlorine atoms. To prevent the corrosion, CHF$_3$ plasma treatment subsequent to the etched has been carried out. A passivation layer is formed by fluorine-related compounds on the etched Al-Cu surface after CHF$_3$ and SF$_{6}$ treatment, and the layer supresses effectively the corrosion on the surface as the CHF$_3$ and SF$_{6}$ treatment pressure increases. The corrosion could be suppressed successfully with CHF$_3$ and SF6 treatment in the pressure of 300mTorr.orr.

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칫솔두부크기와 짜는 방법에 따른 일회 세치제 사용량 조사 (A Survey on the Amount used of Toothpaste According to the Size of Head of Toothbrush and Squeezing Method)

  • 배수명;류다영;김희경
    • 치위생과학회지
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    • 제10권6호
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    • pp.439-443
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    • 2010
  • 본 연구는 과량의 불소세치제 사용을 예방하기 위하여 만3~6세 아동의 불소세치제 사용량을 비교 평가하고자 충남 홍성군에 위치한 어린이집 5곳의 84명을 대상으로 칫솔두부크기와 세치제 짜는 방법에 따른 세치제량을 비교하였고, 실제적으로 어린이를 대상으로 구강보건교육을 시행하고 있는 구강보건교육자인 치위생과 학생 141명을 대상으로 콩알크기(pea-size)로 짜는 방법과, 소량의 세치제를 묻히는(smear) 방법으로 짠 세치제 양을 비교하여 다음과 같은 결과를 얻었다. 1. 어린이용 칫솔에 짠 불소세치제의 양은 0.29 g이었고, 성인용 칫솔에 짠 불소세치제의 양 은 0.34 g으로 유의한 차이가 나타나 작은 크기의 칫솔로 짰을 때 더 적은양의 세치제를 사용하는 것으로 조사되었다(p<0.05). 2. 3-6세 아동이 평소 통상적으로 짜는 방법대로 짠 양이 0.31 g이었고, 콩알크기(pea-size)로 짠 양이 0.21 g이었으며, 소량의 세치제를 묻히는(smear) 방법을 이용하여 짠 양은 0.26 g으로 조사되어, 평소 통상적으로 짜는 방법보다 콩알크기(pea-size)로 짜는 방법이나 소량의 세치제를 묻히는(smear) 방법을 이용하면 더 적은양의 불소세치제를 사용할 수 있는 것으로 조사되었다(p<0.05). 3. 치위생과 학생들을 조사한 결과 콩알크기(pea-size)로 짰을 때의 양은 0.23 g이었고, smear 방법을 이용했을 때는 0.15 g으로 조사되어, 소량의 세치제를 묻히는(smear) 방법을 이용했을 때 더 적은 양의 불소세치제를 사용하는 것으로 조사되었다(p<0.05). 4. 아동과 치위생과 학생들의 세치제 짜는 방법에 따라 차이가 있는지 조사한 결과 콩알크기(pea-size)로 짰을 때는 두 집단 간의 차이가 없었으나(p>0.05), 소량의 세치제를 묻히는(smear)방법으로 짰을 때는 치위생과 학생들이 더 적은양의 불소세치제를 사용하는 것으로 조사되었다(p<0.05) 5. 두부가 작은 칫솔을 사용하면 불소세치제 사용량을 감소시킬 수 있으며, 콩알크기(pea-size)로 짜는 방법과 소량의 세치제를 묻히는(smear) 방법은 불소세치제 사용량의 감소로 부주의한 불소 섭취를 최소화할 수 있어 어린이에게 추천할 수 있다.

$^{18}F$-플루오린 표지를 위한 신개념 반응용매에서 친핵성 불소화 반응 (Nucleophilic Fluorination Reactions in Novel Reaction Media for $^{18}F$-Fluorine Labeling Method)

  • 김동욱;정환정;임석태;손명희
    • Nuclear Medicine and Molecular Imaging
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    • 제43권2호
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    • pp.91-99
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    • 2009
  • Noninvasive imaging of molecular and biological processes in living subjects with positron emission tomography(PET) provides exciting opportunities to monitor metabolism and detect diseases in humans. Measuring these processes with PET requires the preparation of specific molecular imaging probes labeled with $^{18}F$-fluorine. In this review we describe recent methods and novel trends for the introduction of $^{18}F$-fluorine into molecules which in turn are intended to serve as imaging agents for PET study. Nucleophilic $^{18}F$-fluorination of some halo- and mesyloxyalkanes to the corresponding $^{18}F$-fluoroalkanes with $^{18}F$-fluoride obtained from an $^{18}O(p,n)^{18}F$ reaction, using novel reaction media system such as an ionic liquidor tert-alcohol, has been studied as a new method for $^{18}F$-fluorine labeling. Ionic liquid method is rapid and particularly convenient because $^{18}F$-fluoride in $H_2O$ can be added directly to the reaction media, obviating the careful drying that is typically required for currently used radiofluorination methods. The nonpolar protic tert-alcohol enhances the nucleophilicity of the fluoride ion dramatically in the absence of any kind of catalyst, greatly increasing the rate of the nucleophilic fluorination and reducing formation of byproducts compared with conventional methods using dipolar aprotic solvents. The great efficacy of this method is a particular advantage in labeling radiopharmaceuticals with $^{18}F$-fluorine for PETimaging, and it is illustrated by the synthesis of $^{18}F$-fluoride radiolabeled molecular imaging probes, such as $^{18}F$-FDG, $^{18}F$-FLT, $^{18}F$-FP-CIT, and $^{18}F$-FMISO, in high yield and purity and in shorter times compared to conventional syntheses.

전기 방사에 의한 3-Fluorine Poly(ether ether ketones)의 부직포 제조 (Preparation of 3-Fluorine Poly(ether ether ketones) Web by Electro Spinning)

  • 류영준;김학용;이덕래
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 2002년도 봄 학술발표회 논문집
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    • pp.265-267
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    • 2002
  • 섬유를 제조함에 있어 기존의 방법으론 수 마이크론의 섬유를 만들지만 전기방사를 이용한 방법으로는 마이크론이하의 직경을 가진 섬유를 만들수 있어 전기방사에 관한 관심이 증가하고 있다. 전기방사란 고분자 용액 및 용융된 고분자에 고전압을 걸어주어 섬유를 받아주는 콜렉터와 방사되는 팁 사이에 전기장을 형성시켜 부직포를 제조하는 방법이다. 일반적으로 불소를 포함한 방향족 고분자는 그들의 구조 때문에 외부열에 대한 저항력, 내화학성, 기계적, 전기적 특성이 우수하다고 잘 알려져 있다. (중략)

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In-situ Fluorine Passivation by Excimer Laser Annealing

  • Jung, Sang-Hoon;Kim, Cheon-Hong;Jeon, Jae-Hong;Yoo, Juhn-Suk;Han, Min-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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    • pp.155-156
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    • 2000
  • We propose a new in-situ fluorine passivation of poly-Si TFTs by excimer laser annealing to reduce the trap density and improve the reliability significantly. This improvement is due to the formation of stronger Si-F bonds than Si-H bonds which passivate the trap states.

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S-trifluoroacetoxy-trihalomethyl mercaptan의 형성에 관한 연구 (Studies on the synthesis of S-trifluoroacetoxy-trihalomethyl mercaptans)

  • 오동영;김종호
    • 약학회지
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    • 제16권2호
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    • pp.108-112
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    • 1972
  • S-Trifluoroacetoxy-trihalomethyl mercaptans were prepared by reacting metal salt of trihaloacetic acid with perhalomethyl mercaptans in the closed vessel. And besides, certain decomposed states of these products by heat and U.V. were studied by Infra red, N.M.R., molecular weight determination and chemical analysis methods. The results showed that the more fluorine substituted compounds were more stable than the less fluorine substituted ones.

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