• Title/Summary/Keyword: 화학I

Search Result 3,765, Processing Time 0.033 seconds

새로운 조미료 고(I) - 풍미조미료 수요확대

  • 김만조
    • Food Industry
    • /
    • s.16
    • /
    • pp.60-64
    • /
    • 1973
  • 식품의 조미에는 예적부터 식염을 비롯한 장유류를 사용하여 간과 맛을 조성하여 왔다. $\ulcorner$맛있는 식품을 만들기 위한$\lrcorner$ 불가결의 $\ulcorner$조미료$\lrcorner$에 관해서는 이미 잘 알려져 있는 화학조미료와 천연조미료의 2종류로 대별될 수 있다. 최근에 이르러 세계적인 조미료계의 동향을 보면 화학조미료인 핵산계조미료의 보급은 일단락한 느낌이 있으며 각종의 풍미 천연복합조미료가 여러 나라에서 출현되어 전망을 과시하고 있는 상 싶어 보인다.

  • PDF

Synthesis and Photoluminescence Properties of Heteroleptic 9-Arylated Carbazole Iridium(III) Complexes (9-Arylated Carbazole을 주리간드로 사용하는 Heteroleptic Iridium(III) 착물의 합성과 분광학적 특성)

  • Oh, Se Hwan;Yum, Eul Kgun;Kim, Younghoon;Im, Yung-Jae;Heo, Jungseok;Kim, Yeong-Joon
    • Applied Chemistry for Engineering
    • /
    • v.32 no.2
    • /
    • pp.180-189
    • /
    • 2021
  • N-Heteroaryl carbazoles were synthesized with thermal heating in the presence of Cu(I) catalyst and used as main ligands for the preparation of heteroleptic Ir(III) complexes. In these Ir(III) complexes, 6-membered ring structures of Ir-ligand chelation were found by single crystal X-ray diffraction. The blue shift of photoluminescence for Ir(III) complexes was observed in the case of the strong bond formation between Ir and ancillary ligands. It also has been clearly shown that the higher electron density of heteroaryl aromatic ring influenced shorter maximum photoluminescence wavelength (λmax) of Ir(III) complexes. Since the new Ir(III) complexes showed good phosphorescent emission, they could be potentially used as OLED materials in the emission Layer.

Analysis of Medical Student's Need for Pre-Medical Course on the Contents of Science Curriculum in High School (의예과 교육과정에 필요한 고등학교 과학관련 교과목 내용에 대한 요구분석)

  • Park, Hye Jin;Park, Won Kyun;Kim, Yura
    • Journal of Science Education
    • /
    • v.45 no.1
    • /
    • pp.129-141
    • /
    • 2021
  • With the change of the undergraduate medical education system, many medical schools have recently run or developed a medical education curriculum. The premedical curriculum should be designed according to the sequencing and level of the medical curriculum, but there were no discussions on the standards or evidence for the basic science-related subjects. Therefore, this study examines Physics I, Physics II, Life sciences I, Life sciences II, Chemistry I, and Chemistry II, which are the subjects of need assessment exploration. The need assessment used mean, mean difference, and Borich demand, The locus for focus of memory degree and importance, and the result was converted into 76 keywords. The results of this study are expected to be used as basic data for the development of subjects related to basic science in premedical curriculum.

Electrochemical Oxidation of Silver (I) Salt (Ag(I) 염의 전해산화)

  • Duk Mook Kim
    • Journal of the Korean Chemical Society
    • /
    • v.29 no.2
    • /
    • pp.158-163
    • /
    • 1985
  • The anodic oxidations of the Silver(I) / Silver(II) / Silver(III) system have been studied in aq. 2M $AgNO_3$ solution with Platinum and Carbon electrodes. It has been found that $Ag_7O_8NO_3$ can be produced at relatively higher current density. Deposited black Oxy-salt were analyzed with several methods such as oxidizing power, X-ray powder diffraction patterns, thermal analysis, and reduction curves. It decomposed to AgO upon being suspended in boiling water. AgO compound obtained from $Ag_7O_8NO_3$ were purer and denser than Alfa-product AgO.

  • PDF

Molecular Cloning of H-Y Antigen Gene I. Purification of H-Y Antigen by Immunoaffinity Chromatography and Chemiluminescence Immunoassay for the Assay of H-Y Antigen (H-Y 항원 유전자의 cloning에 관한 연구 I. 친화성 크로마토그래피에 의한 H-Y 항원의 분리 정제 및 H-Y 항원 정량을 위한 화학발광 면역 분석법)

  • 김종배;김재홍;백정미;김창규;정길생
    • Korean Journal of Animal Reproduction
    • /
    • v.15 no.2
    • /
    • pp.149-155
    • /
    • 1991
  • 본 실험은 H-Y 항원 유전자 크로닝을 위한 기초연구로서 H-Y 항원의 특성을 규명하기 위하여 친화성 크로마토그래피에 의하여 H-Y 항원을 분리·정제하였다. 정소 추출액을 항체가 결합된 column에 결합시킨 뒤 10% acetic acid로 용출시켰다. 용출된 분획을 모아 농축한 후 HPLC와 SDS-PAGE를 실시하여 H-Y 항원의 분자량은 약 6,7000달톤 임을 알 수 있었으며 isoelectric focusing에 의하여 등전점(pI)은 5.0인 것으로 측정되었다. H-Y 항원에 대한 단일클론항체와 표지항원으로는 H-Y 항원-ABEI(aminobutylethyl isoluminol)를 사용하여 H-Y 항원 정량을 위한 화학발광면역분석법을 개발하였다. 항원항체 반응후 빛의 측정은 NaOH 존재하에서 microperoxidase/H2O2를 이용한 산화반응으로 실시하여 10초간 측정한 빛의 양을 적분하였다. H-Y 항원의 농도와 빛의 양과는 역비례하였으며 감도는 11.8ng/tube 정도이었다.

  • PDF

Effect of the Corrosive Solution Conditions and Scan Rate to the Electrochemical Corrosion on the AISI 304 Stainless Steel (부식액의 조건 및 주사 속도가 AISI 304 스테인리스강의 전기화학적 부식에 미치는 영향)

  • 나은영;백신영
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.21 no.5
    • /
    • pp.535-541
    • /
    • 1997
  • The effect of concentration of each solution( HCI, $H_2SO_4$ and $HNO_3$), scan rate and polished surface condition on the corrosion of AISI 304 Stainless Steel were investigated, utilizing the Method ASTM G5 - 87. It can be concluded that: 1) For the same concentration(i.e. 1N) of each solution the corrosion rate is the highest in HCI and lowest in $HNO_3$. Also, the difference of values of $i_{cirt}$ generated for each solution is significant. 2) As the concentration of the solution $H_2SO_4$ is increased (O.5N, 1N, 2N) the values of $E_{cor}$ $i_{crit}$ and $i_{p}$ are increased. 3) In case of existence of SCN ion of O.OlN, the values of iCTIt and ip generated are approximately 100 times and 1.4 times higher respectively, than in the case of non - existence of $SCN^{-}$. However the existence of $SCN^{-}$ doesn't affect the value of $E_{cor}$ and $E_{p}$. 4) The values of $i_{crit}$ and $i_{p}$ are increased due to the increase of scan rate. But the values of $E_{cor}$ and $E_{p}$ do not depend on the scan rate. 5) The $i_{p}$ value depends greatly on oxygen in the solution, but the changes in values of $E_{cor}$ $i_{crit}$ and $E_{b}$ due to the oxygen are insignificant. 6) If a component is polished using #400, #600 and #800 wet polish paper, the effect of surface condition on variations of values of $i_{crit}$ and $i_{p}$ is slightly significant.

  • PDF

The Complex Formation of Gallium Bromide with i-Propyl Bromide in Nitrobenzene (니트로벤젠용액내에서의 브롬화갈륨과 i-브롬화프로필과의 착물형성에 관한 연구)

  • Oh Cheun Kwun;Dong Sup Lee;Young Hoon Lee
    • Journal of the Korean Chemical Society
    • /
    • v.29 no.1
    • /
    • pp.9-14
    • /
    • 1985
  • The solubilities of i-propyl bromide in nitrobenzene have been measured at 10$^{\circ}$, 19$^{\circ}$ and 25$^{\circ}C$ in the presence and absence of gallium bromide. In the presence of gallium bromide, 1 : 1 complex, i-C$_3$H$_7Br{\cdot}GaBr_3$ is formed in the solution. The instability constant K of the complex formation was evaluated from the following equilibrium equation: i-C$_3$H$_7Br{\cdot}GaBr_3$ ${\rightleftharpoons}$ i-C$_3$H$_7$Br + $\frac{1}{2}$$Ga_2Br_6$. The change of enthalpy, free energy and entropy for the dissociation of the complex were also calculated. From these result, it seems that the stabilities of the complex formation, gallium bromide with alkyl bromide, are directly related with those of the carbonium ions of alkyl bromide.

  • PDF