• Title/Summary/Keyword: rhodamine

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A Study on the Turbulent Characteristics of Rushton Turbine Mixer by Simultaneous Measurement of Velocity and Concentration Field with Stereo-PIV/PLIF Technique (Stereo-PIV/PLIF의 속도장과 농도장 동시측정 기법을 이용한 러쉬톤 교반기내 난류특성에 관한 연구)

  • Min, Young-Uk;Kim, Yun-Gi;Kim, Kyung-Chun
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.694-699
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    • 2003
  • Simultaneous measurement with PLIF(Planar Laser-Induced Fluorescence) and Stereo-PIV(Stereoscopic Particle Image Velocimetry) was performed to investigate the structural characteristics of flow field in Rushton Turbine Mixer. Instantaneous 3D velocity fields are measured by two 2K ${\times}$ 2K CCD cameras focused on an object plane with the angular displacement methods while the concentration fields are obtained through the measurement of the fluorescence intensity of Rhodamine B tracer excited by the second pulse of Nd:Yag laser light. Image distortion due to the camera view-angle is compensated by a mapping function. Finally, the spatial structures of turbulent mixing around Rushton turbine were identified by the calculation of cross-correlation fields between the velocity and concentration field.

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Numerical Analysis Study of the Mixing Mechanism of Non-element Mixer (논 엘레멘트 믹서의 혼합 메커니즘에 관한 수치해석적 검토)

  • You, Sun Ho
    • Journal of ILASS-Korea
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    • v.20 no.1
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    • pp.1-6
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    • 2015
  • Visualization of the mixing pattern in a non-element mixer was carried out using laser induced fluorescence(LIF) to evaluate characteristics of mixer consisting of the main flow pipe and branch flow pipes. The branch flows were injected periodically with the period $T_{in}$ normal to the main flow, and rhodamine B was mixed into the most upstream branch flow to visualize mixing pattern in the main flow pipe by LIF. The length of boundary line L of the LIF image was measured. In this study, a numerical analysis was performed to identify the mixing process of the non-element mixer, and the results were compared with experimental results. Each result was almost the same. When the number of branch flows is increased, the mixing pattern became complicated and was supposed to become chaotic. The length of boundary line L increased exponentially with an increase in the number of branch flows.

INTERFACIAL MORPHOLOGY BETWEEN DENTIN AND ADHESIVES (상아질과 접착제 간의 계면양상)

  • Kang, Ji-Young;Hur, Bock
    • Restorative Dentistry and Endodontics
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    • v.20 no.1
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    • pp.183-192
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    • 1995
  • The purpose of this study was to evaluate the effect of smear layer management on the interfacial morphology between dentin bonding system and dentin. Clearfil New Bond, Scotchbond Multipurpose, Prisma Universal Bond 3 and X-R Bond were used on the cervical dentinal surfaces of bovine incisor teeth. All of the dentin bonding systems were labeled with fluorescene in primer and rhodamine B in adhesive. Specimens of 2~3mm thichness were prepared by longitudinal and labiolingual sectioning. The interface between dentin bonding system and dentin was observed by flouresence imaging with a confocal laser scanning microscope. Following results were obtained. 1. In the specimen of Clearfil New Bond, dentinal tubules were widened by destruction of peritubular dentin in the course of treatment with phosphoric acid of high concentration. 2. Hybrid layer was observed in the specimen of Scotchbond Multipurpose and X-R Bond. 3. In the specimen of Prisma Universal Bond 3, the penetraton of adhesive was not observed clearly.

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Toxicity and Biomedical Imaging of Fluorescence-Conjugated Nanoparticles in Hematopoietic Progenitor Cells

  • Min, Gye-Sik;Kim, Dong-Ku
    • Reproductive and Developmental Biology
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    • v.35 no.4
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    • pp.503-510
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    • 2011
  • Cellular uptake of nanoparticles for stem cell labeling and tracking is a critical technique for biomedical therapeutic applications. However, current techniques suffer from low intracellular labeling efficiency and cytotoxic effects, which has led to great interest in the development of a new labeling strategy. Using silica-coated nanoparticles conjugated with rhodamine B isothiocyanate (RITC) (SR), we tested the cellular uptake efficiency, biocompatibility, proliferation or differentiation ability with murine bone marrow derived hematopoietic stem/progenitor cells. The bone marrow hematopoietic cells showed efficient uptake with SR with dose or time dependent manner and also provided a higher uptake on hematopoietic stem/progenitor cells. Biocompatibility tests revealed that the SR had no deleterious effects on cell cytotoxicity, proliferation, or multi-differentiation capacities in vitro and in vivo. SR nanoparticles are advantageous over traditional labeling techniques as they possess a high level of cellular internalization without limiting the biofunctionality of the cells. Therefore, SR provides a useful alternative for gene or drug delivery into hematopoietic stem/progenitor cells for basic research and clinical applications.

Control of surface metal nanostructure with physical vapor deposition (물리기상증착을 이용한 금속표면 나노구조제어)

  • Jeong, Ji-Hye;Han, Min-A;Kim, Hyeon-Jong;Lee, Ho-Nyeon
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.251-251
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    • 2015
  • 최근 질병 조기진단에 대한 사회적 요구가 높아짐에 따라 이에 대한 기술에 관심이 집중되고 있다. 그 중 표면증강라만산란(surface enhanced Raman scattering(SERS))을 이용하여 인체 내 소량의 바이오마커를 검출하는 연구가 활발히 진행중이다. 본 연구에서는 바이오마커의 검지감도를 최대치로 증가시키기 위해 SERS 기판의 나노구조를 최적화 하였다. SERS 기판 표면의 나노구조, 크기, 형상, 밀도 등에 따라 검지감도가 변화되기 때문에 이를 제어하기 위해 증착공정 변수에 변화를 주어 표면의 나노구조를 형성하였다. 이를 분석하기 위해 SEM, XRD를 사용하였으며 최적화된 SERS 기판을 활용하여 Rhodamine 6G의 신호가 $1{\times}10^5$ 이상의 enhancing factor를 확인하였다.

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A Study on Organic Multithin Layer EL Devices (다층 유기 초박막 EL소자에 관한 연구)

  • Cho, S.R.;Kim, J.J.;Park, J.E.;Son, W.K.;Lim, K.J.;Park, S.G.;Lee, J.S.
    • Proceedings of the KIEE Conference
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    • 1997.07d
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    • pp.1516-1518
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    • 1997
  • Recently lots of study on EL have been performed by other researcher. Organic multilayer system of TPD/$Alq3$ and Rhodamine 101 perchrolate/Alq3/ was constructed on ITO and finally Al as cathodic electrode. The thickness of emitting layer was $150{\AA}$ and device was fabricated by changing amount of dopant. AFM image for each surface morphology and EL spectra using fluoromax-2 was investigated. Electrical and emission properties of EL device was dependent on deposition method and condition.

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Colocalization of ${\alpha}$of Gq Protein with Actin Filaments in L8E63 Cells

  • Chae, Sungsuk;Park, Dongeun
    • Animal cells and systems
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    • v.1 no.1
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    • pp.93-98
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    • 1997
  • The present study investigated the cellular localization of a-subunit of Gq (Gaq) protein in developing L8E63, rat skeletal muscle cell line. The colocalization of Gaq with actin cytoskeleton was demonstrated by double-labeling experiments. In mononucleated myoblasts, the immuno-fluorescence staining pattern of Gaq was almost identical with that of F-actin visualized with rhodamine-conjugated phalloidin. However, this colocalization of Gaq with cytoskeleton was not maintained in multinucleated myotubes. The staining pattern of Gaq in myotubes did not match with any specific subcellular structure, but appeared as a uniformly distributed diffuse staining throughout the whole cell surface. Interestingly, change in the expression level of Gaq was not detected during myoblast differentiation, suggesting that actin-associated Gaq protein might dissociate from the cytoskeleton as cells differentiate. Immunocytochemical experiments using specific antibodies directed against several G proteins indicated that the subcellular localizations of Gai1, Gai2, Gai3, and Gao were different from those obtained with Gaq.

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Identification of Inhibitors Against BAK Pore Formation using an Improved in vitro Assay System

  • Song, Seong-Soo;Lee, Won-Kyu;Aluvila, Sreevidya;Oh, Kyoung Joon;Yu, Yeon Gyu
    • Bulletin of the Korean Chemical Society
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    • v.35 no.2
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    • pp.419-424
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    • 2014
  • The pro-apoptotic BCL-2 family protein BID activates BAK and/or BAX, which form oligomeric pores in the mitochondrial outer membrane. This results in the release of cytochrome c into the cytoplasm, initiating the apoptotic cascade. Here, we utilized liposomes encapsulating sulfo-rhodamine at a controlled temperature to improve upon a previously reported assay system with enhanced sensitivity and specificity for measuring membrane permeabilization by BID-dependent BAK activation. BAK activation was inhibited by BCL-$X_L$ protein but not by a mutant protein with impaired anti-apoptotic activity. With the assay system, we screened a chemical library and identified several compounds including trifluoperazine, a mitochondrial apoptosis-induced channel blocker. It inhibited BAK activation by direct binding to BAK and blocking the oligomerization of BAK.

Preparation of Nanosized Palladium-Graphene Composites and Photocatalytic Degradation of Various Organic Dyes

  • Kim, Jae Jin;Ko, Weon Bae
    • Elastomers and Composites
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    • v.51 no.1
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    • pp.10-16
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    • 2016
  • Nanosized palladium particles were synthesized using palladium(II) chloride, trisodium citrate dihydrate, and sodium borohydride under stirring condition. Nanosized palladium-graphene composites were prepared from palladium nanoparticles, and graphene was enclosed with polyallylamine under stirring condition for 1 h followed by ultrasonication for 3 h. Nanosized palladium-graphene composites were heated in an electric furnace at $700^{\circ}C$ for 2 h and characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. UV-vis spectrophotometry was used to evaluate the nanosized palladium-graphene composites as a catalyst in the photocatalytic degradation of various organic dyes such as methylene blue, methyl orange, rhodamine B, and brilliant green under ultraviolet light at 254 nm.

Determination of Stream Reaeration Coefficient Using Modified Gas Tracer Method (Modified Gas Tracer Method 를 이용한 하천 재폭기계수의 산정)

  • 조영준
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.41 no.4
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    • pp.57-65
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    • 1999
  • A modified gas tracer method was used to obtain reaeration coefficient from an artificial channel and a reach of Bokha stream, Ichon city. Propane was used as the tracer gas and Rhodamine-B dye as a dispersion and dulution tracer. Concentrations of propane in water sample were measured using a gas chromatograph and concentrationsof dye using UV-Spectrophotometer. To compare measured values with predicted values,commonly used 14 equations were selected . Results of this study suggested that the modified gas tracer method is a potentially useful procedure for th edetermination of reaeration cofficients. However, estimated reaeration coefficients from predictive equations were significantly different from that of this study. Therefore, when using predictive equations, careful selection of equation with consideration for hydraulic characteristics such as flow depth and average velocity, or use of newly derived predictive equation which is adequate for questioned stream would be needed.

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