• Title/Summary/Keyword: guest

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A Smart Fluorescent Macrocycle with Recognition-Ability of the Neutral Molecules

  • Choi, Chang-Shik;Kim, Mi-Kyoung;Jeon, Ki-Seok;Lee, Ki-Hwan
    • Journal of Photoscience
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    • v.11 no.1
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    • pp.7-9
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    • 2004
  • The synthesized macrocycle L was found to be a smart fluorescent receptor which distinguishable efficiently from various neutral molecules with the functional groups such as the electron donating (X =$CH_3$, N($CH_3$)$_2$ and O$CH_3$) and electron withdrawing groups (X =F and Cl), respectively. In the case of guest molecules containing electron donating groups, the fluorescence of macrocycle L was enhanced in the presence of the guest molecules. On the contrary, in the case of guest molecules containing electron withdrawing groups, it was almost quenched in the presence of those.

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A Study on the Inclusion Complexation of Octyldimethyl p-aminobengoate with \brta -Cyclodextrin$ (Octyldiinethyl p-aminobenzoate와 \brta -Cyclodextrin$의 포접화합물에 관한 연구)

  • Lee, Chang-Hak;So, Bu-Yeong;Kim, Yeong-Su
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.15 no.1
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    • pp.51-62
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    • 1989
  • Inclusion complex formation of octyldimethl p-aminobenzoate with $\beta$-cyclodextrin in aqueous solution and in the solid state was studied by the solubility method, spectroscopic(UV, FT-lR) and X -ray diffractometry. The solid complex of octyldimethy p-aminobenzoate with $\beta$-cyclodextrin was obtained in molar ratio of 1 : 2(guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and p -cyclodextrin in water at $25^{\circ}C$. The results indicated that the solubility of the guest molecule was higher by the formation of $\beta$-cyclodextrin inclusion complex.

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Translated Block Optimization of Dynamic Binary Translator for Embedded System Virtualization (임베디드 시스템 가상화를 위한 동적 이진 변환기의 변환 블록 최적화)

  • Hwang, Wonjun;Park, Sihyeong;Kim, Hyungshin
    • IEMEK Journal of Embedded Systems and Applications
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    • v.12 no.6
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    • pp.385-393
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    • 2017
  • As the use of mobile devices such as smartphones increases, there is growing interest on the benefits of virtualization in embedded systems. Full virtualization has the advantage of running the guest virtual machine without modifying the guest operating system. However, full virtualization suffers slow execution speed due to the cost of context switching between the virtual machines and the virtual machine monitor. In this paper, we propose a translated block and context switching optimization to improve the guest execution speed in the embedded system. As a result, the improved dynamic binary translator is up to 5.95 times faster than the native execution. Performance degradation is less than that of the other virtualization system.

Amino-β-cyclodextrin Complex Assisted Ionization for Labile Sesamins and their Ion-mobility Separation in ESI Q-TOF MS

  • Sugahara, Kohtaro;Horikawa, Manabu;Yamagaki, Tohru
    • Mass Spectrometry Letters
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    • v.6 no.1
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    • pp.17-20
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    • 2015
  • Sesamin, one of the lignans in sesame seed, was a labile compound in MS and it was reported that the protonated molecule of sesamin decomposed easily in ES ionization process and it cannot be detected (G. Yan, et al., Rapid Commun Mass Spectrom. 2007, 21, 3613-3620). To protect labile compounds, an amino-cyclodextrin (NCyD) was added to the sample to promote the host-guest interaction complex in ESI-MS. As a result, sesamin was ionized as the NCyD-sesamin-NCyD (1:2) complex without undesired decomposition, suggesting that the amino-CyDs assist the ionization of the labile molecules capped with CyDs by host-guest interaction and these compounds were ionized without their decomposition, those are like amino-CyD complex-assisted ionization. The amino-CyD complexes of sesamin and sesamolin were also analyzed by their ion-mobility MS.

Study of Methane Storage through Structure Transition of Gas Hydrate (가스하이드레이트 구조 변형을 통한 메탄 저장에 관한 연구)

  • Lee, Ju-Dong;Lee, Man-Sig;Kim, Young-Seok
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.54-57
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    • 2006
  • Structure H formation experiments were conducted in a semi-batch stirred vessel using methane as the small guest substance and neohexane(NH), tert-butylmethylether(TBME) and methylcyclohexane(MCH) as the large molecule guest substance (LMGS). The results indicate that the rates of gas uptake and induction times are generally dependent on the magnitude of the driving force. When tert-butyl methyl ether is used as the LMGS rapid hydrate formation, much smaller induct ion time and rapid decomposition can be achieved. Liquid-liquid equilibrium (LLE) data for the above LMGS with water have been measured under atmospheric pressure at 275.5, 283.15K, and 298.15K. It was found that TBME is the most water soluble followed by NM and MCH. The solubility of water in the non-aqueous liquid was found to increase in the following order: MCH

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An implementation of reliable data sharing multi-stack system in virtualized environment (신뢰성 있는 멀티스택 기반의 가상화된 데이터 동시공유 시스템의 구현)

  • Han, Kyujong;Jeon, Dongwoon;Kim, Doohyun
    • IEMEK Journal of Embedded Systems and Applications
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    • v.11 no.5
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    • pp.259-265
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    • 2016
  • In this paper, we present an architecture for the fault isolation by applying virtualization-based multi-stack technologies. We propose the simultaneous sharing and switching mechanism using virtualied serial communications. Each guest OS has its own virtual serial device. The distribution module provides communications between the guest OS's through the virtual serial devices and simultaneously detect the liveness of the guest OS. The suggested mechanism has been implemented in VirtualBox and shows satisfactory performance in transmission speed and data sharing capability with virtual RS232.

A Study on the Inclusion Complexation of Octyldimethyl p-aminobenzoate with ${\beta}-Cyclodextrin$ (Octyldimethl p-aminobenzoate 와 ${\beta}-Cyclodextrin$의 포접화합물(包接化合物)에 관(關)한 연구(硏究))

  • Lee, Chang-Hak;So, Boo-Young;Kim, Young-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.6 no.1
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    • pp.59-66
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    • 1989
  • Inclusion complex formation of octyldimethyl p-aminobenzoate with ${\beta}-cyclodextrin$in aqueous solution and in the solid state was studied by the solubility method, spectroscopic (UV, FT-IR) and X-ray diffractornetry. The solid complex of octyldimethyl p-aminobenzoate with ${\beta}-cyclodextrin$ was obtained in molar ratio of 1:2 (guest/host). A spatial relationship between host and guest molecule was clearly reflected in the magnitude of the apparent stability constant (K') and in the stoichiometry of the inclusion complex. Furthermore, a typical type Bs phase-solubility diagram was obtained for octyldimethyl p-aminobenzoate and ${\beta}-cyclodextrin$ in water at $25^{\circ}C$. The results indicated that the solubility of the guest molecule was higher by the formation of ${\beta}-cyclodextrin$ inclusion complex.

Computational Chemistry Study on Gas Hydrate Formation Using HFC & HCFC Refrigerants (R-134a, R-227ea, R-236fa, R-141b) (수소불화탄소 및 수소염화불화탄소 냉매(R-134a, R-227ea, R-236fa, R-141b)를 이용한 가스 하이드레이트 형성에 관한 계산화학적 해석)

  • Kim, Kyung Min;An, Hye Young;Lim, Jun-Heok;Lee, Jea-Keun;Won, Yong Sun
    • Korean Chemical Engineering Research
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    • v.55 no.5
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    • pp.704-710
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    • 2017
  • Although the desalination technique using gas hydrate formation is at a development stage compared to the commercially well-established reverse osmosis (RO), it still draws attention because of its simplicity and moderate operational conditions especially when using refrigerants for guest gases. In this study, DFT (density functional theory)-based molecular modeling was employed to explain the energetics of the gas hydrate formation using HFC (hydrofluorocarbon) and HCFC (hydrochlorofluorocarbon) refrigerants. For guest gases, R-134a, R-227ea, R-236fa, and R-141b were selected and three cavity structures ($5^{12}$, $5^{12}6^2$, and $5^{12}6^4$) composed of water molecules were constructed. The geometries of guest gas, cavity, and cavity encapsulating guest gas were optimized by molecular modeling respectively and their located energies were then used for the calculation of binding energy between the guest gas and cavity. Finally, the comparison of binding energies was used to propose which refrigerant is more favorable for the gas hydrate formation energetically. In conclusion, R-236fa was the best choice in terms of thermodynamic spontaneity, less toxicity, and low solubility in water.

Detection of ClO4- via A Hypersensitive Receptor : Unusual Electrostatic Equilibria between Host and Guest in Aqueous Media (고감도 수용체에 의한 ClO4- 검출 : 수용액에서 주-객 이온간의 평형)

  • Lee, Young-A;Hong, Jongki;Jung, Ok-Sang
    • Analytical Science and Technology
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    • v.15 no.1
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    • pp.31-35
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    • 2002
  • A useful receptor for the sensing of ${CIO_4}^-$ species with remarkable selectivity has been developed. The hypersensitive interaction between a host and a guest has been investigated for the complex $[Pd(Me_4en)(Py_2S){\cdot}2ClO_4]_4$ ($Me_4en$ = N,N,N',N'-tetramethylethylenediamine; $Py_2S$ = 4,4'-dipyridyl sulfide). The pyridyl moiety of $Py_2S$ exhibits two sets of $^1H$ resonances that are delicately dependent upon temperature, concentration, and media. The nonrigidity has been explained in terms of an electrostatic equilibrium between the tetrameric host and the ${CIO_4}^-$ guest. The equilibrium is a useful method for the detection of ${CIO_4}^-$ anion with remarkable selectivity via "a restricted guest within a big host" in aqueous solution.