• Title/Summary/Keyword: Chemistry class

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Study of Anisotropic Photoluminescence and Energy Transfer in Oriented Dye-incorporating Zeolite-L Monolayer

  • Lee, Jin-Seok
    • Bulletin of the Korean Chemical Society
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    • v.31 no.8
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    • pp.2190-2194
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    • 2010
  • Development of the methods to organize zeolite microcrystals into closely packed and uniformly aligned monolayers on various substrates have been pursued viewing microparticles as a novel class of building blocks. We now report that the vertically aligned zeolite monolayer can be applied as novel supramolecularly organized systems for anisotropic photoluminescence in high dichroic ratio, to study energy transfer dynamics between the internal and external fluorophores, and to develop zeolite-based advanced materials. Study of polarized fluorescence spectroscopy and angle-dependent intensity change with dye molecules in different surroundings further provides insight into molecular interactions that can be used for the future design of optoelectronic device in nanometer size. In addition, this report shows that isolating of organic dye through surface treatment is crucial for preventing the egress of the incorporated dye molecules from the channels of zeolite to the solution and to enhance the anisotropic luminescence.

Efficiency of Lamarckian Genetic Algorithm in Molecular Docking of Phenylaminopyrimidine (PAP) Derivatives: A Retrospect Study

  • Ratilla, Eva Marie A.;Juan, Amor A. San
    • Proceedings of the Korean Society for Bioinformatics Conference
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    • 2004.11a
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    • pp.203-209
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    • 2004
  • Molecular docking using Lamarckian genetic algorithm of AutoDock 3.0 (AD3) was employed to understand in retrospect the selectivity of phenylaminopyrimidine (PAP) derivatives against the kinase domain c-Abl, implicated in chronic myelogenous leukemia (CML). The energetics of protein-ligand complex was scored using AD3 to identify active drug conformations while Ligplot and ligand protein contact (LPC) programs were used to probe schematic molecular recognition of the bound inhibitor to the protein. Results signify correlation between model and crystal structures of STI-571 compound or Imatinib (IM), a PAP derivative and now clinically proven for its efficacy in CML. A prospect active form Abl inhibitor scaffold from matlystatin class of compounds will be published elsewhere.

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Method Development of Verapamil in Presence of NSAIDs using RP-HPLC Technique

  • Sultana, Najma;Arayne, M. Saeed;Waheed, Abdul
    • Bulletin of the Korean Chemical Society
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    • v.32 no.7
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    • pp.2274-2278
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    • 2011
  • Verapamil is a calcium channel blocker and is classified as a class IV anti-arrhythmic agent. It is used in the control of supra ventricular tachyarrhythmias, and in the management of classical and variant angina pectoris. It is also used in the treatment of hypertension and used as an important therapeutic agent for angina pectoris, ischemic heart disease, hypertension and hypertrophic cardiomyopathy. Verapamil commonly co-administered with NSAIDs (non-steroidal anti-inflammatory drugs) i.e. diclofenac sodium, flurbiprofen, Ibuprofen, mefanamic acid and meloxicam. A simple and rapid RP-HPLC method for simultaneous determination and quantification of verapamil and NSAIDs was developed and validated. The mobile phase constituted of acetonitrile: water (55:45) whose pH was adjusted at 2.7 and pumped at a flow rate of 2.0 mL $min^{-1}$ at 230 nm. The proposed method is simple, precise, accurate, low cost and least time consuming for the simultaneous determination of verapamil and NSAIDs which can be effectively applied for the analysis of human serum.

Molecular Mechanisms of Succinate Dehydrogenase Inhibitor Resistance in Phytopathogenic Fungi

  • Sang, Hyunkyu;Lee, Hyang Burm
    • Research in Plant Disease
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    • v.26 no.1
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    • pp.1-7
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    • 2020
  • The succinate dehydrogenase inhibitor (SDHI) is a class of fungicides, which is widely and rapidly used to manage fungal pathogens in the agriculture field. Currently, fungicide resistance to SDHIs has been developed in many different plant pathogenic fungi, causing diseases on crops, fruits, vegetables, and turf. Understanding the molecular mechanisms of fungicide resistance is important for effective prevention and resistance management strategies. Two different mechanisms have currently been known in SDHI resistance. The SDHI target genes, SdhB, SdhC, and SdhD, mutation(s) confer resistance to SDHIs. In addition, overexpression of ABC transporters is involved in reduced sensitivity to SDHI fungicides. In this review, the current status of SDHI resistance mechanisms in phytopathogenic fungi is discussed.

CHEMICAL EVOLUTION IN VeLLOs

  • Lee, Jeong-Eun
    • Journal of The Korean Astronomical Society
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    • v.40 no.4
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    • pp.83-89
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    • 2007
  • A new type of object called "Very Low Luminosity Objects (VeLLOs)" has been discovered by the Spitzer Space Telescope. VeLLOs might be substellar objects forming by accretion. However, some VeLLOs are associated with strong outflows, indicating the previous existence of massive accretion. The thermal history, which significantly affects the chemistry, between substellar objects with a continuous low accretion rate and objects in a quiescent phase after massive accretion (outburst) must be greatly different. In this study, the chemical evolution has been calculated in an episodic accretion model to show that CO and $N_2H^+$ have a relation different from starless cores or Class 0/I objects. Furthermore, the $CO_2$ ice feature at $15.2{\mu}m$ will be a good tracer of the thermal process in VeLLOs.

A Study on Interdisciplinary Education Model of Using Climate Change Film-Focusing on Documentary An Inconvenient Truth (기후변화 영화를 활용한 융합교육 모형연구: 다큐멘터리 <불편한 진실>을 중심으로)

  • Hwang, Young-mee;Oh, Jung-jin
    • Journal of Engineering Education Research
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    • v.19 no.5
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    • pp.57-64
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    • 2016
  • This study is about interdisciplinary education model of using Davis Guggenheim's documentary film on global warming which is a big concern in climate change issues, An Inconvenient Truth. It based on Al Gore's slide speech. Through a course student analyzed the cause and phenomenon of global warming resulted from increase of $CO_2$ by using fossil fuel and its environmental science effects-heat wave, desertification, tornado, hurricane, sea level rise caused by melting glaciers, destroying ecosystem like habitat degradation of wild animals, for example polar bear, extreme cold wave caused by change of ocean currents- of global warming. After, student discussed of efforts to prevent global warming. This educational model is appropriate for lower grade student of environmental engineering and also available for converged majors or general education class.

A Study of Class Design for Science Education by Computational Thinking (과학교육을 위한 컴퓨팅 사고력 도입 수업 설계)

  • Choe, Eun-Jeong;Paik, Seoung-hey
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2014.07a
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    • pp.169-170
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    • 2014
  • 본 논문에서는 초등학생에게 스크래치 프로그램을 처치하여 과학교육을 위한 컴퓨팅 사고력 도입에 관한 수업을 설계 제안하고자 한다. 과학교육의 반성에 시작된 컴퓨팅 사고력 도입을 위해 4학년 과학교육과정을 분석하였으며, 스크래치 프로그램을 처음 접하는 학생들이 쉽게 애니메이션 결과물을 도출할 수 있도록 식물의 한살이 단원을 재구성하여 적용하였다. 추후에 컴퓨팅 사고력을 바탕으로 한 스크래치 프로그램 적용이 초등학생의 창의성 함양과 과학 학습정서에 어떤 영향을 주는지에 대한 후속연구를 진행하고자 한다.

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Novel 3D nanofabrication technique and its applications

  • Jeon, Seok-U
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.05a
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    • pp.15.1-15.1
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    • 2009
  • Nano transfer printing and micro contact printing is well known printing method based on soft lithography which uses conformal soft elastomer with designed surface relief structures. Here I introduce another class of novel 3D nanofabrication technique by using the same elastomer but in a different manner. The approach, which we refer to as proximity field nanopatterning, uses the surface-reliefed elastomers as phase masks to pattern thick layers of transparent, photosensitive materials. Aspects of the optics, the materials, and the physical chemistry associated with this method are outlined. A range of 3D structures illustrate its capabilities, and several application examples demonstrate possible areas of use in technologies ranging from microfluidics to photonic materials to density gradient structures for chemical release and high-energy density science.

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Adsorption of Uranium (VI) Ion on 1-Aza-12-Crown-4 Synthetic Resin with Styrene Hazardous Material

  • Kim, Joon-Tae
    • Journal of Integrative Natural Science
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    • v.6 no.2
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    • pp.104-110
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    • 2013
  • 1-Aza-12-crown-4 macrocyclic ligand was combined with styrene (2th petroleum in 4th class hazardous materials) divinylbenzene copolymer having 1%, 2%, 3%, and 6% crosslinks by a substitution reaction, in order to synthesize resin. These synthetic resins were confirmed by chlorine content, elementary analysis and IR-spectrum. As the results of the effects of pH, equilibrium arrival time, crosslink of synthetic resin, and dielectric constant of a solvent on uranium ion adsorption for resin adsorbent, the uranium ion showed high adsorption at pH 3 or over and adsorption equilibrium of uranium ion was about 2 hours. In addition, adsorption selectivity for the resin in methanol solvent was the order of uranium ($UO_2{^{2+}}$) > iron ($Fe^{3+}$) > lutetium ($Lu^{3+}$) ions, adsorbability of the uranium ion was in the crosslinks order of 1%, 2%, 3%, and 6% was increased with the lower dielectric constant.

Complex Chalcogenides as Thermoelectric Materials: A Solid State Chemistry Approach

  • 정덕영;Lykourgos Iordanidis;최경신;Mercouri G. Kanatzidis
    • Bulletin of the Korean Chemical Society
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    • v.19 no.12
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    • pp.1283-1293
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    • 1998
  • A solid state chemical approach to discover new mateials with enhanced thermoelectric properties is described. The aim is to construct three-dimensional bismuth chalcogenide framework structures which contain tonically interacting alkali or alkaline earth atoms. The alkali atoms tend to have soft "rattling" type phonon modes which result in very low thermal conductivity in these materials. Another desirable feature in this class of compounds is the low crystal symmetry and narrow band-gaps. Several promising materials such as BaBiTe3, KBi6.33S10, K2Bi8S13, β-K2Bi8Se13, K2.5Bi8.5Se14, Ba4Bi6Se13, Eu2Pb2Bi6Se13, Al1+xPb4-2xSb7+xSe15 (A=K, Rb), and CsBi4Te6 are described.