• Title/Summary/Keyword: PCH

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Synthesis and Structure of trans-Bis[bis(diphenylphosphino)ethane]cyanohydridoiron(II), trans[FeH(CN)$(dppe)_2$](dppe=$Ph_2PCH_2CH_2PPh_2)$ ([FeH(CN)$(dppe)_2$ 착물의 합성 및 구조)

  • 이재경;최남선;이순원
    • Korean Journal of Crystallography
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    • v.10 no.1
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    • pp.45-50
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    • 1999
  • Ar 기류하에서 trans-[FeH(NCCH2CH2CH2Cl)(dppe)2][BF4], 1과 KCN이 반응하여 trans-[FeH(CN)(dppe)2], 2가 생성되었다. 이 화합물의 구조가 NMR, IR, 원소분석, 그리고 X-ray 회절법으로 규명되었다. 착물 2의 결정학 자료: 단사정계 공간군 p21/c, a=13.580(1) b=20.178(2) , c=17.592(3) , β=92.22(1)o, Z=4,(wR2)=0.0659(0.1692).

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Neural Network Based Adaptive Control for a Flying-Wing Type UAV with Wing Damage (주익이 손상된 전익형 무인기를 위한 신경회로망 적응제어기법에 관한 연구)

  • Kim, DaeHyuk;Kim, Nakwan;Suk, Jinyoung;Kim, Byungsoo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.5
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    • pp.342-349
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    • 2013
  • A damage imposed on an unmanned aerial vehicle changes the flight dynamic characteristics, and makes difficult for a conventional controller based on undamaged dynamics to stabilize the vehicle with damage. This paper presents a neural network based adaptive control method that guarantees stable control performance for an unmanned aerial vehicle even with damage on the main wing. Additionally, Pseudo Control Hedging (PCH) is combined to prevent control performance degradation by actuator characteristics. Asymmetric dynamic equations for an aircraft are chosen to describe motions of a vehicle with damage. Aerodynamic data from wind tunnel test for an undamaged model and a damaged model are used for numerical validation of the proposed control method. The numerical simulation has shown that the proposed control method has robust control performance in the presence of wing damage.

Development of Highly Thermal Conductive Liquid Crystalline Epoxy Resins Bearing Phenylcyclohexyl Mesogenic Moieties (Phenylcyclohexyl mesogenic moieties를 함유한 고 열전도성 액정성 에폭시 수지의 개발)

  • Jeong, Iseul;Kim, Youngsu;Goh, Munju
    • Composites Research
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    • v.30 no.6
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    • pp.350-355
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    • 2017
  • The new liquid crystalline (LC) epoxy was designed by substituting the phenylcyclohexyl (PCH) mesogen moiety with an alkyl chain at the 2,5 position of the diglycidyl terephthalate. The mesomorphic properties were evaluated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). All LC epoxy derivatives exhibited an enantiotropic smectic phase upon heating and cooling process. The LC phase temperature range was widened by mixing the eutectic mixture of LC epoxies. Interestingly, the cured LC epoxy exhibited the highest thermal conductivity of $0.4W{\cdot}m^{-1}{\cdot}K^{-1}$. The novel LC epoxy with high thermal conductivity might be used as a composite material for electronic and display devices.

Synthesis and Crystal Structure of $Me_2Pt(PPh_2CH_2C(t-Bu)=N-N=CMe(2-py)-\kappa^2N,P)$ ($Me_2Pt(PPh_2CH_2C(t-Bu)=N-N=CMe(2-py)-\kappa^2N,P)$의 합성 및 결정 구조)

  • Cho Sung Il;Kang Sang Ook;Chang K.
    • Korean Journal of Crystallography
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    • v.15 no.2
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    • pp.83-87
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    • 2004
  • An organometallic complex. $Me_2Pt(PPh_2CH_2C(t-Bu)=N-N=CMe(2-py)-\kappa^2N,P)$ was synthesized from phosphinohydrazone $Ph_2PCH_2C(t-Bu)=NNH_2$, 2-acetylpyridine, and $[PtMe2({\mu}-SMe_2)]_2$. The molecular structure of this complex has been determined by X-ray diffraction. Crystallographic data: monoclinic, space group $P2_1/n,\;a=11.6926(7)\;{\AA},\;b=15.6607(19)\;{\AA},\; c=14.6125(6)\;{\AA},\;\beta=93.018(4)^{\circ},\;Z=4,\;V=2672.0(4)\;{\AA}^3$. The structure was solved by direct methods and refined by full-matrix least-squares methods to give a model with a reliability factor R = 0.0363 for 5238 reflections.

Determination of Tyrosinase mRNA in Melanoma by Reverse Transcription-PCR and Optical Mirror Resonance Biosensor

  • Taeboo Choe;Park, Inchul;Seokil Hong
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.7 no.4
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    • pp.212-215
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    • 2002
  • Tyrosinase transcript In the blood Is known as the marker of malignant melanoma and it has been often determined by using reverse transcription-polymerase chain reaction (RT-PCA) . However, after the PCR process, the quantification of amplified CDMA by the gel electrophoresis is not reliable and time-consuming. for this reason, we tried to quantify the PCR product using a cuvette-type biosensor, where the oligonucleotide probe was immobilized on the cuvette surface and the single strand CDMA, the denatured PCH product, was then hybridized onto the immobilized probe to give a response signal. The response was Immediate and takes 15 min to obtain a stable signal. The biosensor was much more sensitive comparing to the gel electrophoresis method. The quantification of PCR product using a cuvette-type biosensor was feasible and rapid.

C-H…H-Fe Dihydrogen Bonding: Synthesis and Structure of $trans-[FeH(NCS(i-Pr)-S)(dppe)_2]I$ $(dppe=Ph_2PCH_2Ch_2PPh_2)$ (C-H…H-Fe Dihydrogen 결합: $trans-[FeH(NCS(i-Pr)-S)(dppe)_2]I$ 착물의 합성 및 구조)

  • 이지화;이순원
    • Korean Journal of Crystallography
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    • v.11 no.1
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    • pp.10-15
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    • 2000
  • Compound trans-[FeH(NCS(i-Pr)-S)(dppe)₂](1) reacted with isopropyl iodide (i-PrI) to give an Fe(II)-organic isothiocyanide complex, trans-[FeH(NCS(i-Pr)-S)(dppe)₂]I (2). Compound 2 was structurally characterized, in which the hydride ligand appears to be involved in the "dihydrogen" bonding, M-H…H-C. Crystallographic data for 2: monoclinic space group P2₁/n, a=13.490(2)Å, b=17.269(3)Å, c=21.384(3)Å, β=90.682(7)°, Z=4, R(wR₂)=0.0348(0.0894).

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Effect of Conjugation of Mesogenic Core of Nematic Liquid Crystals for Polar Anchoring Strength on Rubbed Polyimide Film (러빙처리된 폴리이미드막에 있어서의 극각 방향의 결합강도에 관한 네마틱 액정의 분자구조 변화의 효과)

  • Seo, Dae-Shik;Kwak, Hee-Ro;Kobayashi, Shunsuke
    • Proceedings of the KIEE Conference
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    • 1995.11a
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    • pp.414-416
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    • 1995
  • We have studied the effect of the mesogenic core of nematic liquid crystals (NLCs) for polar (out-of-plane tilt) anchoring strength on rubbed polyimide (PI) films. The order of polar anchoring strength for NLCs on rubbed PI films is 5CB > PCH5 > CCH5. This order is the same for all rubbing strengths investigated. From these results, we suggest that the polar anchoring strength strongly depends on the polarizability of the NLCs.

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Relationship of the pretill angle and nematic liquid crystals on LCD (LCD에 있어서의 네마틱 액정과 프리틸트각의 발생과의 관계)

  • 서대식;유문상;황정연
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.263-266
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    • 1998
  • In this study, the effect of the crystallinity of polyimide (Pl) and the birefringence of the nematic liquid crystal (NLC) for pretilt angle generation on rubbed PI surface containing thiophenylene moieties has been demonstrated. The induced optical retardation produced in rubbed Pl surfaces decreases on increasing the imidization temperature. We suggest that the pretilt angle of 4-cyano-4'-n-pentybiphenyl (5CB) depends on the crystallinity of the rubbed Pl. The order of pretilt angle in NLCs is 5CB>PCH5$\geq$CCH5 at rubbing strength(RS)=150mm (medium rubbing) on rubbed PI surfaces. We suggest that on rubbed Pl surfaces the pretilt angle increases with increasing number of phenylrings in the NLC core.

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Syntheses and Theoretical Study of Palladium(II) Complexes with Aminophosphines as 7-Membered Chelate Rings

  • 김봉곤;양기열;정맹준;이배욱;도명기
    • Bulletin of the Korean Chemical Society
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    • v.18 no.11
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    • pp.1162-1166
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    • 1997
  • Nature of palladium(Ⅱ) complexes with 7-membered chelates was studied by experimental and theoretical methods on a Pd(L)Cl2 system, where L is Ph2PNHCH2CH2NHPPh2(L1), Ph2PNHC6H4NHPPh2(L2). The palladium(Ⅱ) complexes were prepared and characterized by elemental analysis, IR, UV, 1H, and 31P NMR spectroscopy. Ab initio calculations with geometry optimizations were also performed for related model systems, Pd(L)Cl2; L=R2PNH(CH2)2NHPR2(L3), R2PNHC6H4NHPR2(L4), R2P(CH2)4PR2(L5), R2PCH2(C6H4)CH2PR2(L6); R=H, CH3.

Biosynthesis of Two Hydroxybenzoic Acid-Amine Conjugates in Engineered Escherichia coli

  • Kim, Song-Yi;Kim, Han;Kim, Bong-Gyu;Ahn, Joong-Hoonc
    • Journal of Microbiology and Biotechnology
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    • v.29 no.10
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    • pp.1636-1643
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    • 2019
  • Two hydroxybenzoyl amines, 4-hydroxybenzoyl tyramine (4-HBT) and N-2-hydroxybenzoyl tryptamine (2-HBT), were synthesized using Escherichia coli. While 4-HBT was reported to demonstrate anti-atherosclerotic activity, 2-HBT showed anticonvulsant and antinociceptive activities. We introduced genes chorismate pyruvate-lyase (ubiC), tyrosine decarboxylase (TyDC), isochorismate synthase (entC), isochorismate pyruvate lyase (pchB), and tryptophan decarboxylase (TDC) for each substrate, 4-hydroxybenzoic acid (4-HBA), tyramine, 2-hydroxybenzoic acid (2-HBA), and tryptamine, respectively, in E. coli. Genes for CoA ligase (hbad) and amide formation (CaSHT and OsHCT) were also introduced to form hydroxybenzoic acid and amine conjugates. In addition, we engineered E. coli to provide increased substrates. These approaches led to the yield of 259.3 mg/l 4-HBT and 227.2 mg/l 2-HBT and could be applied to synthesize diverse bioactive hydroxybenzoyl amine conjugates.