• Title/Summary/Keyword: Light extinction

Search Result 172, Processing Time 0.028 seconds

A Study on the Extraction of Soluble Colorants of the Gardenia jasminoides Ellis (수용성 치자 색소의 추출에 관한 연구)

  • Kim, Kwang Soo;Kim, Yeon Joong
    • Textile Coloration and Finishing
    • /
    • v.9 no.3
    • /
    • pp.10-17
    • /
    • 1997
  • The study was performed to obtain the optimum extraction conditions for crocin from gardenia fructus. Generally crocin is unstable on heat, light, acid and base solution. The extraction efficiency of crocin from gardenia depended upon the extraction time, extraction temperature, pH in the extraction bath and the optimum conditions of crocin extraction were determined as 60 minutes of extraction time, 4$0^{\circ}C$ of extraction temperature, pH 7 of extraction bath. The molar extinction coefficient of crocin was 12,515 and the color yield of purified crocin was about six times higher than that of non-purified crocin. The heat-stability at extraction temperature and lightstability in irradiation with xenon lamp for one hour of the purified crocin were higher than those of non-purified crocin. Intensity of &{\lambda}_{max}&of crocin was decreased by irradiation for one hour but UV-Vis. spectra of crocin was not changed. The colors of purified and non-purified crocin dissolved wit methanol was evaluated by means of CIE L* a* b* system.

  • PDF

Circuit Design of Ultraviolet Flame-Sensor for Fire-Fighting Appliances (자외선 센서를 이용한 화재감지기 응용 회로 설계)

  • Kim, Yeong-Min;Kim, Jong-Man
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2008.04c
    • /
    • pp.1-5
    • /
    • 2008
  • In this paper, we proposed that when combustible burn with ultraviolet radiation, introduce fire detector with sensor of private-use detectable light energy as ultraviolet in energy of electromagnetic-wave type radiate from flame. This research using ultraviolet flame sensor is pyro-electric ultraviolet sensor based black body radiation theory. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research introduced UV flame detector and proposed method of false alarm reduced to resemble fire. the result proposed the prevention and extinction of fire technique degree, certificated operation of detector.

  • PDF

Synthesis and Photovoltaic Properties of Organic Photosensitizers for Application of Dye Sensitized Solar Cells (페노시아진을 이용한 염료감응형 태양전지 고효율 염료합성)

  • Yang, Hyun Sik;Shin, So Yeon;Kim, Yeun Ji;Kim, Jae Hong
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.05a
    • /
    • pp.119.2-119.2
    • /
    • 2011
  • Dye-sensitized solar cells (DSSC) are currently attracting wide spread academic and commercial interest for the conversion of sunlight into electricity because of their easy manufacturing process and high efficiency. The solar energy conversion efficiencies of DSSC are strongly dependent on dye molecules adsorbed on the TiO2 surface which used for photosensitization of sun light, since an excited state of dye could inject an electron into the conduction band of semiconductor. We have developed novel organic dyes which have phenothiazine moieties as an electron donor in their charge-transfer chromophore for application of DSSCs. We had synthesized a series of phenothiazine derivatives which have different wave length absorbing chromophore in the molecule with high molar extinction coefficient. The photovoltaic performance of DSSC composed of organic chromophores with broad wavelength absorption property were measured and evaluated by comparison with that of pristine ruthenium dye.

  • PDF

Properties of the Variation of the Infrared Emission of OH/IR Stars I. The K Band Light Curves

  • Suh, Kyung-Won;Kwon, Young-Joo
    • Journal of Astronomy and Space Sciences
    • /
    • v.26 no.3
    • /
    • pp.279-286
    • /
    • 2009
  • To study properties of the variation of the infrared emission of OH/IR stars, we collect and analyze the infrared observational data in K band for nine OH/IR stars. We use the observational data obtained for about three decades including recent data from the two micron all sky survey (2MASS) and the deep near infrared survey of the southern sky (DENIS). We use Marquardt-Levenberg algorithm to determine the pulsation period and amplitude for each star and compare them with previous results of infrared and radio investigations.

Quantitative Measurements of Soot Particles in a Laminar Diffusion Flame Using a LII/LIS Technique (LII/LIS 기법을 이용한 층류확산화염 매연입자의 정량화)

  • Chung, J.W.;Lee, W.;Han, Y.T.;Kim, B.S.;Lee, C.B.;Kim, D.J.;Lee, K.H.
    • Journal of the Korean Society of Combustion
    • /
    • v.8 no.4
    • /
    • pp.1-8
    • /
    • 2003
  • In this study, the quantification of soot particles in laminar diffusion flame with LII/LIS methods was performed. In these quantification, soot diameter, number density and volume fraction are included. For the quatification of soot particles, calibration tests are needed and the development of algorithm has to be performed. So, in this study, extinction and scattering test at co-flow burner were performed to acquire calibration data. And algorithm for LII/LIS simultaneous measurement for the quantification of soot were developed. The algorithm, which was the quantification of simultaneous photographing using one ICCD camera, to measure LII/LIS signal simultaneously, the best fitted light intensity and acquisition time was needed.

  • PDF

A study of optical characteristics correlated with low dielectric constant of SiOCH thin films through Ellipsometry (Ellipsometry를 이용한 저 유전 상수를 갖는 SiOCH박막의 광학특성 연구)

  • Park, Yonh-Heon;Hwang, Chang-Su;Kim, Hong-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2010.06a
    • /
    • pp.198-198
    • /
    • 2010
  • The low-k SiOCH thin films were prepared by CCP-PECVD method using BTMSM(Bis-trimethylsilylmethane) precursors deposited on p-Si wafer. The structural complexity originate the complex refractive constants of the films, and resulted the elliptical polarization of the incident linearly polarized light source of Xe-ramp in the range from 190nm to 2100nm. Phase difference and amplitude ratio between s wave and p wave propagating through SiOCH thin film was studied. After annealing, the amplitude of p wave was reduced more than s wave, and phase difference between p and s wave was also reduced.

  • PDF

Flexure hinge mechanism having amplified rectilinear motion for confocal scanning microscopy using optical section

  • Kwon, Oh-Kyu;Park, Poo-Gyeon
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2001.10a
    • /
    • pp.162.6-162
    • /
    • 2001
  • Confocal scanning microscopy (CSM) is an important instrument in a wide variety of imaging applications because of its ability to provide three-dimensional images of thick, volume specimens. The mechanism for two-dimensional beam scanning and optical sectioning has an important roe in CSM as the three-dimensional profiler. This optical sectioning property arises from the use of a point detector, which serves to attenuate the signals from out-of-focus. The intensity profile for the open loop scanning should be matched with its response for the standard. The non-linearity can be minimized with the optical sectioning or the optical probe of the closed loop control. This paper shows the mathematical expression of the light such as the extinction curve in the optical fields of system using AO deflector, the axial/lateral response experimentally when the error sources change, and the methods of optical sectioning. Thorough design of optical sectioner is crucial to the success of CSM in the field ...

  • PDF

Integrated-Optic Polarization Controlling Devices Using Electro-Optic Polymers

  • Oh, Min-Cheol;Hwang, Wol-Yon;Kim, Jang-Joo
    • ETRI Journal
    • /
    • v.18 no.4
    • /
    • pp.287-299
    • /
    • 1997
  • Integrated-optic polarization controlling devices such as polarizers, polarization splitters, and polarization converters, are proposed and demonstrated in nonlinear optic polymers. Poling-induced birefringence in electro-optic polymers is exploited to fabricate the devices. The polymeric waveguide polarizers show low excess losses, and extinction ratios of 20.7 dB and 17.1 dB for TM-pass and TE-pass polarizers, respectively. The polymeric waveguide polarization splitters exhibit TE-TM mode splittings with crosstalk of 14.2 dB and 10.1 dB for TM and TE mode splittings, respectively. The polymeric waveguide polarization converters show successful TE/TM polarization mode conversion with conversion efficiencies of higher than 30 dB. The device employs poling-induced waveguides which have slowly rotating azimuth angle of optic axis along the light propagation direction. The novel polarization converter is insensitive to wavelength and easier to fabricate than the other polarization converters containing periodic structures.

  • PDF

Wide-Viewing Liquid Crystal Displays with Periodic Surface Gratings

  • Lee, Sin-Doo;Park, Jae-Hong;Yoon, Tae-Young;Yu, Chang-Jae
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2002.08a
    • /
    • pp.947-952
    • /
    • 2002
  • A new concept of forming self-aligned multidomains is used for fabricating wide-viewing liquid crystal displays (LCDs) with periodic surface gratings.An array of the periodic surface gratings is produced on substrates using a photosensitive polymer by the illumination o. the UV light through a patterned photomask. A multidomain structure is naturally formed on the grating surface by the initial director distortions together with continuous variations of an external electric field. The LCD cells with periodic surface gratings are found to show excellent extinction in the off-state and wide-viewing property m the on-state.

  • PDF

Monitoring of Cleanliness Level in Hydraulic Systems: Obtaining Reliable On-Line data

  • Hong, Jeong-Hee;Day, Mike
    • Journal of Drive and Control
    • /
    • v.9 no.2
    • /
    • pp.28-38
    • /
    • 2012
  • Monitoring of system cleanliness levels and counting of particulate contaminant are fundamental to achieving hydraulic system reliability as any departure from the specified cleanliness level is often a precursor to future failures. On-line monitoring of cleanliness levels has the advantage of giving data both very quickly and accurately as environmental influences are eliminated. In this way, corrective actions can be promptly implemented. Most on-line instruments are sensitive to system conditions to a greater or lesser extent, but Automatic Particle Counters (APCs) working on light extinction principles are especially sensitive to the presence of optical interfaces caused by such conditions as fluid mixtures, emulsions, free water and air bubbles. These conditions give erroneous data and can result in drawing incorrect conclusions, wasting maintenance time and ultimately, reduced user confidence in cleanliness monitoring. This paper describes such conditions and shows how the correct selection of the analysis technique can result in reliable cleanliness level data.