• Title/Summary/Keyword: Cyclic compound

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Effect of vacuum regeneration of activated carbon on volatile organic compound adsorption

  • Pak, Seo-Hyun;Jeon, Yong-Woo
    • Environmental Engineering Research
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    • v.22 no.2
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    • pp.169-174
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    • 2017
  • Vacuum swing adsorption (VSA) is a promising treatment method for volatile organic compounds (VOCs). This study focuses on a VSA process for regenerating activated carbon spent with VOCs, and then investigates its adsorption capacities. Toluene was selected as the test VOC molecule, and the VSA regeneration experiments results were compared to the thermal swing adsorption process. Cyclic adsorption-desorption experiments were performed using a lab-scale apparatus with commercial activated carbon (Samchully Co.). The VSA regeneration was performed in air (0.5 L/min) at 363.15 K and 13,332 Pa. The comparative results depicted that in terms of VSA regeneration, it was found that after the fifth regeneration, about a 90% regeneration ratio was maintained. These experiments thus confirm that the VSA regeneration process has good recovery while operating at low temperatures (363.15 K) and 13,332 Pa.

Synthesis of New 6-(4-Fluorophenyl)-5-(2-substituted pyrimidin-4-yl)imidazo[2,1-b] thiazole Derivatives and their Antiproliferative Activity against Melanoma Cell Line

  • Park, Jin-Hun;Oh, Chang-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2854-2860
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    • 2010
  • Synthesis of a new series of pyrimidinyl-imidazo[2,1-b]thiazole derivatives is described. Their antiproliferative activity against A375 human melanoma cell line was tested and the effect of substituents on the pyrimidinyl ring side chain was investigated. The biological results indicated that most of the newly synthesized compounds showed moderate activity against A375, compared with Sorafenib. Among all of these derivatives, the cyclic sulfamide derivatives IIIa, IIIb, and IIIe showed the most potent antiproliferative activity against A375 human melanoma cell line. The IC50 values of compounds IIIa,b were in nanomolar scale. In addition, compound IIIe ($IC_{50}=1.9\;{\mu}M$) also demonstrated more potent antiproliferative activity compared with Sorafenib ($IC_{50}=5.6\;{\mu}M$).

Electrochemical Characteristics of 5,10,15,20-Tetrakis-Octadecyloxymethylphenyl-Porphyrin-Zn(II) Langmuir-Blodgett (LB) Films

  • Koo, Ja-Ryong;Choi, Don-Soo;Kim, Young-Kwan;Kim, Jung-Soo
    • KIEE International Transactions on Electrophysics and Applications
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    • v.11C no.3
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    • pp.58-62
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    • 2001
  • Since Metallo-Porphyrin (MP) is very interesting compound due to its unique electronic and redox properties and it is also chemically and thermally stable, MP has been studied for potential memory and switching devices. In this study, thin films of 5,10,15,20-Tetrakis-Octadecyloxymethylphenyl-Porphyrin-Zn(II) were prepared by the Langmuir-Blodgett (LB) method and characterized by using UV/vis absorption spectroscopy and cyclic voltammetry. It was found that the proper transfer surface pressure for film deposition was 25 mN/m and the limiting area per molecule was 135 ${\AA}^2$/molecule. The current-voltage (I-V) characteristics of these films were investigated. Further details on the electrical properties of Porphyrin-Zn(II) derivative films will be discussed.

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Examination on Electrochemical Behaviors of Niobium Chloride in Molten LiCl-KCl by Cyclic Voltammetry

  • Jeong, Gwan Yoon;Park, Jaeyeong
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2018.11a
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    • pp.299-300
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    • 2018
  • Electrochemical behaviors of Nb ion in the $LiCl-KCl-NbCl_5$ molten salt were examined. Cyclic voltammograms with different scan rates and scan range at $450^{\circ}C$ showed possible electrochemical redox reactions which were identified by comparison to the literature data. Peak potentials for each redox reaction were consistent with the literature, but some redox reactions were not clearly defined due to the formation of subchloride compound in chloride salt. The electrochemical behaviors of Nb ion related to the subchloride formation as well as Nb metal deposition will be investigated for the future work.

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Preparation and Curing Studies of Maleimide Bisphenol-A Based Epoxy Resins

  • Nanjunda Gowda, Shivananda Kammasandra;Mahendra, Kadidal Nagappa
    • Bulletin of the Korean Chemical Society
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    • v.27 no.10
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    • pp.1542-1548
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    • 2006
  • Maleimide modified epoxy compounds were prepared by reacting N-(4-hydroxyphenyl) maleimide (HPM) with diglycidylether of bisphenol-A. Triphenylphosphine was used as catalyst and methylethylketone as solvent. The resulting compound possessed both the oxirane ring and maleimide group. The curing reaction of the maleimide epoxy compound with amine curing agents such as 1-(2-aminoethyl) piperazine (AEP) and 5-amino-1,3,3-trimethylcyclohexane methylamine isophorone diamine, IPDA) were studied. Incorporation of maleimide groups in the epoxy resin provides cyclic imide structure and high cross-linking density to the cured resins. The cured samples were found to have good thermal stability, chemical resistance (acid/alkali/solvent) and water absorption resistance.

A Macrocyclization of (2R)-2-(N,N-Ditosylimido) -3-butenyl methyl malonate by Using Palladium Catalyst (팔라듐 촉매를 이용한 (2R)-2-(N,N-Ditosylimido)-3-butenyl methyl malonate의 거대고리화 반응)

  • Kim, Gyu-Soon;Rhee, Hak-June
    • Journal of the Korean Chemical Society
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    • v.44 no.1
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    • pp.30-36
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    • 2000
  • Upon Pd(0)-catalyzed coupling reaction of (2R)-2-(N,N-ditosylimido)-3-butenyl methyl malonate (4) which was selected for the total synthesis of A-factor, (3R)-2-(6-methylheptanoyl)-3-hydroxy methyl-4-buttinolide (1), an unexpected 14-membered cyclic compound, bis(2-methoxycabonyl-(4E)-hexenolide) (15) was obtained. The structure of this compound was conformed by X-ray crystallography. This result implies that this method can be applied the synthesis of various size of symmetrical macrocyclic compounds.

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Formation Characteristics of PM and SOF by Spray Combustion of Marine Heavy Fuel Oil

  • Kim, Houng-Soo;Murakami, T.;Nishida, Osami;Fujita, H.;Harano, W.
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.2
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    • pp.292-299
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    • 2004
  • This study is intended to check a temperature of the flame to raise by burning A heavy oil in a boiler. to measure the concentration of DS and SOF after collecting the PM(Particulate Matters). and to analyze the components ingredients of SOF by G.C Mass for presupposing the generation of particulate matters(soot). It is thought that the methyl(CH3) of the cyclic compound is changed to the materials of 2 cycles and 3 cycles after becoming CH by dehydrogenation and also mixing with the CH of a chain compound. form H-$\cdot$C=C$\cdot$-H that is mentioned before. in order to become Polycyclic Aromatic Hydrocarbon.

Efficiency appraisal of 22.9kV tree retardant power cable (22.9kV 트리억제형 전력케이블의 성능평가)

  • Kim, We-Young;Yun, Dae-Hyuk;Park, Tae-Gone
    • Proceedings of the KIEE Conference
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    • 2002.11a
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    • pp.179-182
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    • 2002
  • XLPE compound have used for insulation of 22.9(kV) power cable. But tree retardant power cable has developed and is going to br used commonly. TR XLPE compound retard production and growth of water tree. In this paper, tensile strength, elongation at break, degree of crosslinking, lightning impulse test, AC breakdown test, cyclic aging for 14days and accelerated water treeing test of TR XLPE insulated power cable were examined according to the KEPCO buying spec. & AEIC CS 5-94 standards. before and after As the result, tensile strength, elongation at break and degree of crosslinking test results of TR XLPE insulation were higher than requirement values. After accelerated water treeing test for 120 days, 240 days and 360 days, AC breakdown voltages were not decreased for accelerated water treeing aging duration

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The inhibitory effects of glabridin on human platelet aggregation and thrombus formation

  • Sang-Nam Park;Hyuk-Woo Kwon
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.455-461
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    • 2023
  • Glycyrrhiza glabra is a well-known medicinal herb that grows in various parts of the world and glabridin is a major chemical compound that is found in the root extract of Glycyrrhiza glabra. Glabridin is a natural compound known to have antioxidant, anti-inflammatory, anti-atherogenic, anti-osteoporotic and skin-whitening. In this study, we investigated if glabridin inhibited platelet aggregation and thrombus formation. We observed that glabridin inhibited collagen-induced platelet aggregation and suppressed signal transduction molecules such as phosphatidylinositol-3 kinase (PI3K), Akt, glycogen synthase kinase-3α/β (GSK-3α/β), SYK, cytosolic phospholipase A2, and p38 expression. In addition, glabridin suppressed thromboxane A2 generation and thrombin-induced clot retraction. Taken together, glabridin showed strong antiplatelet effects and may be used to block thrombosis- and platelet-mediated cardiovascular diseases.

Electrochemical Behavior of Ce ion and Bi ion in LiCl-KCl Molten Salt

  • Kim, Beom-Kyu;Han, Hwa-Jeong;Park, Ji-Hye;Kim, Won-Ki;Park, Byung Gi
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2017.05a
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    • pp.227-228
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    • 2017
  • In this paper, electrolytic behavior of Cerium and Ce-Bi ion system was studied. The electrochemical behavior of Ce was studied in $LiCl-KCl-CeCl_3$ molten salts using electrochemical techniques Cyclic Voltammetry on tungsten electrodes at 773K. During the process of CV electrolysis, intermetallic compound were observed of Ce, Cex-Biy. Further study, in order to determine clarity of diffusion coefficient in this experiment, we will compare result of electrochemistry method and we also need to quantitative research.

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