• 제목/요약/키워드: Crystal shift

검색결과 245건 처리시간 0.023초

Gold-protein A Complex 항체 고정화법을 이용한 Salmonella spp.의 신속 검출 (Rapid Detection of Salmonella spp. by Antibody Immobilization with Gold-protein A Complex)

  • 박인선;김남수
    • 한국식품과학회지
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    • 제31권1호
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    • pp.1-6
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    • 1999
  • Salmonella spp.의 신속한 검출을 위하여 발진모듈, 수정결정 진동측정기, 박막형태의 수정결정으로 이루어진 압전류적(piezoelectric, PZ) 항체센서 시스템을 구성하였다. 수정결정의 금전극 표면에 Salmonella 구조 항원(common structural antigen)에 대한 항체를 protein A를 사용하여 고정화하고, 항체가 고정화된 수정결정과 미생물간의 결합반응에 의한 질량증가로 나타나는 진동수의 감소량을 측정하였다. PZ 항체센서는 $35^{\circ}C$, pH 7.2의 0.1M 인산 완충용액에서 Salmonella균에 대하여 가장 높은 감응도를 나타내었다. PZ 항체센서의 반응은 Salmonella균에 대하여 매우 선택적이었고 polystyrene bead 첨가시 센서의 감응도가 크게 증가하였다. Salmonella균의 농도가 $10^5{\sim}10^6\;CFU/mL$의 범위 내에 있을 때 쌍대수좌표에서 직선구간의 검량선을 얻을 수 있었고, Salmonella 검출에 소요되는 시간은 50분이내 이었다.

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Regiospecific Protein Perturbation on F NMR Shifts and Photoisomerization of Fluororhodopsins. An Interpretation Based on Recent Crystal Structures of Rhodopsin

  • Colmenares, Letica U.;Liu, Robert S.H.
    • Journal of Photoscience
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    • 제10권1호
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    • pp.81-87
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    • 2003
  • Based on structural information provided by recently reported crystal structures of rhodopsin, we present rationales for the regiospecific protein perturbation on the previously reported $\^$19/F chemical shifts of the vinyl and trifluoromethylrhodopsins and their photoproducts. The crystal structures also suggest that H-bonding is a likely cause for the earlier reported regiospecific photoisomerization of the 10-fluororhodopsins. Photoisomerization was revealed by chemical shift of the photoproducts. Additionally, possible use of 3-bond F,F coupling constants for following photoisomerization of retinal-binding proteins is discussed.

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Electro-Optical and Switching Behavior of In-plane Switching Twisted Nematic Liquid Crystal Display

  • Kimura, Munehiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.1092-1095
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    • 2003
  • A driving mechanism and excellent features for an in-plane switching twisted nematic liquid crystal mode (IT mode) that could possibly improve the viewing-angle and color shift characteristics and the cell gap error tolerance is proposed. .It is important that the surface azimuthal anchoring strength of the liquid crystal cell differs at the upper and lower substrates. Furthermore. as a rubbing-free LCD. amorphously aligned in-plane switching twisted nematic mode (a-IT mode) is also demonstrated.

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Eelectro-optic Behavior of Opal-LC Photonic Crystals

  • Kang, Dae-Seung
    • Journal of Information Display
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    • 제2권4호
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    • pp.19-22
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    • 2001
  • In this paper, we describe the electro-optic effects of photonic crystals made of a synthetic opal filled with a nematic liquid crystal(LC). By applying an external electric field, a shift in the Bragg reflection peak position(stop band) and a field-induced change in its peak reflectivity are observed. These significant surface alignment effects of the opal-LC composite are discussed in a similar manner for Freederick-type transitions of LC within a confined geometry in the presence of external fields.

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수정진동자에 의한 LB초박막의 평가 (Evaluation of Langmuir-Blodgett Ultra-thin Films by using a Quartz Crystal)

  • 최용성;박옥순;김철홍;장상목;권영수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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    • pp.39-41
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    • 1992
  • The characteristics of LB ultra-thin film multi-layers were evaluated by the AT-cut quartz crystal. Cholesterol and phosphatidyl choline LB multi-layers were deposited on the surface of quartz crystal by using vertical lifting method and horizontal lifting method. There was good relationship between deposition ratio and frequency shift, and the frequency was more stable at the case of horizontal lifting method to the vertical lifting method.

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6채널 압전소자를 이용한 냄새인식에 관한 연구 (A Study on the Identification Odorants using Six Channel Piezoelectric Crystals)

  • 권영수;장상목;박옥순;최용성
    • 대한전기학회논문지
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    • 제41권8호
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    • pp.947-950
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    • 1992
  • At-cut quartz crystal has been applied as chemical vapour sensors. The responses of quartz crystal at 9 MHz coated with phosphatidylglycerol(PG), phosphatidylinositol(PI), phosphatidylethanolamine(PE), phosphatidylserine(PS), and lipid A(LA) are determined for amyl acetate, acetoin, menthone and other organic gases which showed different affinities for each lipid. The identification of odorants depending on the species of lipid used for coating is discussed in terms of the normalized resonant frequency shift pattern.

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Crystal growth from melt in combined heater-magnet modules

  • Rudolph, P.;Czupalla, M.;Dropka, N.;Frank-Rotsch, Ch.;KieBling, F.M.;Klein, O.;Lux, B.;Miller, W.;Rehse, U.;Root, O.
    • 한국결정성장학회지
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    • 제19권5호
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    • pp.215-222
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    • 2009
  • Many concepts of external magnetic field applications in crystal growth processes have been developed to control melt convection, impurity content and growing interface shape. Especially, travelling magnetic fields (TMF) are of certain advantages. However, strong shielding effects appear when the TMF coils are placed outside the growth vessel. To achieve a solution of industrial relevance within the framework of the $KRISTMAG^{(R)}$ project inner heater-magnet modules(HMM) for simultaneous generation of temperature and magnetic field have been developed. At the same time, as the temperature is controlled as usual, e.g. by DC, the characteristics of the magnetic field can be adjusted via frequency, phase shift of the alternating current (AC) and by changing the amplitude via the AC/DC ratio. Global modelling and dummy measurements were used to optimize and validate the HMM configuration and process parameters. GaAs and Ge single crystals with improved parameters were grown in HMM-equipped industrial liquid encapsulated Czochralski (LEC) puller and commercial vertical gradient freeze (VGF) furnace, respectively. The vapour pressure controlled Czochralski (VCz) variant without boric oxide encapsulation was used to study the movement of floating particles by the TMF-driven vortices.

Stretched-Exponential 형태의 문턱전압 이동 모델의 SPICE구현 (Implementation of Stretched-Exponential Time Dependence of Threshold Voltage Shift in SPICE)

  • 정태호
    • 반도체디스플레이기술학회지
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    • 제19권1호
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    • pp.61-66
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    • 2020
  • Threshold voltage shift occurring during operation is implemented in a SPICE simulation tool. Among the shift models the stretched-exponential function model, which is frequently observed from both single-crystal silicon and thin-film transistors regardless of the nature of causes, is selected, adapted to transient simulation, and added to BSIM4 developed by BSIM Research Group at the University of California, Berkeley. The adaptation method used in this research is to select degradation and recovery models based on the comparison between the gate and threshold voltages. The threshold voltage shift is extracted from SPICE transient simulation and shows the stretched-exponential time dependence for both degradation and recovery situations. The implementation method developed in this research is not limited to the stretched-exponential function model and BSIM model. The proposed method enables to perform transient simulation with threshold voltage shift in situ and will help to verify the reliability of a circuit.

Calculation of NMR Shift in Paramagnetic System When the Threefold Axis is Chosen as the Quantization Axis (Ⅰ). The NMR Shift for a 3d$^1$ System in a Strong Crystal Field of Octahedral Symmetry

  • Ahn, Sang-woon;Park, Euisuh;Lee, Kee-Hag
    • Bulletin of the Korean Chemical Society
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    • 제4권3호
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    • pp.103-114
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    • 1983
  • The NMR shift arising from the electron angular momentum and the electron spin dipolar-nuclear spin angular momentum interaction has been examined for a $3d_1$ system in a strong octahedral crystal field when the threefold axis is chosen as the quantization axis. To investigate the NMR shift in this situation, first, we have extended the evaluation of the hyperfine integrals to any pairs of 3d orbitals adopting a general method which is applicable to a general vector R, pointing in arbitrary direction in space. Secondly, a general expression using a nonmultipole technique is derived for the NMR shift resulting from the electron angular momentum and the electron spin dipolar-nuclear spin angular momentum interactions. From this expression all the multipolar terms are determined. ${\Delta}B/B$ for the $3d_1$ system in this case is compared with that for the 3d1 system when the z axis is chosen as the quantization axis. When we choose the threefold axis as the quantization axis, it is found that along the , and axes, ${\Delta}B/B$ values are significantly different from each other and along the , <-1-1-1>, <-11-1>, , <-1-11>, , and <-111> axes, ${\Delta}B/B$ values are however the same. We also find that the 1/R7 term contributes dominantly to the NMR shift for all values of R. When 1/$R^5$ term is included, there is good agreement between the exact solution and the multipolar terms when $R\; {\leqslant}\;0.35\;nm.$.

Calculation of the NMR Cheimical Shift for a 4d$^1$ System in a Strong Crystal Field Environment of Trigonal Symmetry with a Threefold Axis of Quantization

  • Ahn, Sang-Woon;Oh, Se-Woung;Ro, Seung-Woo
    • Bulletin of the Korean Chemical Society
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    • 제7권3호
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    • pp.170-178
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    • 1986
  • The NMR chemical shift arising from 4d electron angular momentum and 4d electron angular momentum and 4d electron spin dipolar-nuclear spin angular momentum interactions for a $4d^1$ system in a strong crystal field environment of trigonal symmetry, when the threefold axis is chosen to be the axis of quantization axis, has been examined. A general expression using the nonmultipole expansion method (exact method) is derived for the NMR chemical shift. From this expression all the multipolar terms are determined. We observe that along the (100), (010), (110), and (111) axes the NMR chemical shifts are positive while along the (001) axis, it is negative. We observe that the dipolar term (1/R3) is the dominant contribution to the NMR chemical shift except for along the (111) axis. A comparison of the multipolar terms with the exact values shows also that the multipolar results are exactly in agreement with the exact values around $R{\geqslant}0.2$ nm. The temperature dependence analysis on the NMR chemical shifts may imply that along the (111) axis the contribution to the NMR chemical shift is dominantly pseudo contact interaction. Separation of the contributions of the Fermi and the pseudo contact interactions would correctly imply that the dipolar interaction is the dominant contribution to the NMR chemical shifts along the (100), (010), (001), and (110) axes, but along the (111) axis the Fermi contact interaction is incorrectly the dominant contribution to the NMR chemical shift.