• Title/Summary/Keyword: Lambert-Beer law

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Photochemical bleaching properties of photopolymer (포토폴리머의 광화학 표백 특성)

  • 성기영;경천수;이영락;곽종훈;최옥식;이윤우;이인원;서호형
    • Korean Journal of Optics and Photonics
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    • v.10 no.4
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    • pp.335-341
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    • 1999
  • We fabricate acrylamide photopolymer as a holographic recording material and investigrate photobleaching characteristics. To explain the photobleaching kinetics of photopolymer we adopt two models of the Beer-Lambert law and optical transmittance based on rate equations obtained from a simplified energy-band model. The Beer-Lambert law is in good agreement with the experimental results in a first short-time region but not in long-time region. But the optical transmittance model based on rate equations explains the experimental results very well in both short-and long-time regions.

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Calculation of Light Penetration Depth in Photobioreactors

  • Lee, Choul-Gyun
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.4 no.1
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    • pp.78-81
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    • 1999
  • Light penetration depth in high-density Chlorella cultures can be successfully estimated by Beer-Lambert's law. The efficiency of light energy absorption algal cultures was so high that algal cells near the illuminating surface shade the cells deep in the culture. To exploit the potential of high-density algal cultures, this mutual shading should be eliminated or minimized. However, providing more light energy will not ease the situation and it will simply drop the overall light utilization efficiency.

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A Study on Structural-Thermal-Optical Performance through Laser Heat Source Profile Modeling Using Beer-Lambert's Law and Thermal Deformation Analysis of the Mirror for Laser Weapon System (Beer-Lambert 법칙을 적용한 레이저 열원 프로파일 모델링 및 레이저무기용 반사경의 열변형 해석을 통한 구조-열-광학 성능 연구)

  • Hong Dae Gi
    • Journal of Aerospace System Engineering
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    • v.17 no.4
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    • pp.18-27
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    • 2023
  • In this paper, the structural-thermal-optical performance analysis of the mirror was performed by setting the laser heat source as the boundary condition of the thermal analysis. For the laser heat source model, the Beer-Lambert model considering semi-transparent optical material based on Gaussian beam was selected as the boundary condition, and the mechanical part was not considered, to analyze the performance of only the mirror. As a result of the thermal analysis, thermal stress and thermal deformation data due to temperature change on the surface of the mirror were obtained. The displacement data of the surface due to thermal deformation was fitted to a Zernike polynomial to calculate the optical performance, through which the performance of the mirror when a high-energy laser was incident on the mirror could be predicted.

Quantitative Dispersion Evaluation of Carbon Nanotubes Reinforced Polymer Nano-composites (탄소나노튜브 첨가 고분자 나노복합재료의 정량적 분산도 평가)

  • Lee, Sang-Bok;Jeong, Bo-Hwa;Yi, Jin-Woo;Lee, Won-Oh;Um, Moon-Kwang
    • Polymer(Korea)
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    • v.35 no.1
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    • pp.60-65
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    • 2011
  • In order to maximize the performance of polymer nano-composites, it is essential to understand an effect of a dispersion state on material properties as well as to achieve highly dispersed composites. In this work, a simple quantitative approach to evaluate the degree of dispersion was suggested for carbon nanotube (CNT) embedded polymer nano-composites. Through UV-visible spectroscopy analysis, the transmittance of nano-composites was measured at various dispersion states and it was found that the transmittance reduced as the dispersion state of CNT improved. Based on the results, an effective concentration factor for quantitative evaluation of dispersion state was introduced into the Beer-Lambert transmittance law. The proposed method and parameter to evaluate the degree of dispersion were verified by analyzing the transmittances at different dispersion states of CNT, concentrations of CNT and sample thicknesses.

Holographic recordings in acrylamide photopolymer (Acrylamide Photopolymer의 제작 및 홀로그램 기록 특성)

  • 경천수;성기영;곽종훈;최옥식;이윤우;이인원;서호형;이일항
    • Korean Journal of Optics and Photonics
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    • v.9 no.1
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    • pp.31-37
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    • 1998
  • We fabricated acrylamie photopolymer holographic recording materials by photopolymerization of acrylamide, and described hologram formation process. Light absorption and phtobleaching process by MB(methylene blue) dye and radical polymerization process due to TEA(triethanolamind) are explained in detail. We adopted the Beer-lambert law in order to explain the photobleaching kinetics. Dependencies of diffraction efficiency of the hologram on monomer amout and the exposure are investigated. The scattering effect caused by grain of polymer crystal, and fixing method are also illustrated.

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Effect of Red-emitting Sr2.41F2.59B20.03O74.8:Eu0.12,Sm0.048 Phosphor on Color Rendering Index and Luminous Efficacy of White LEDs

  • Nguyen, Anh Q.D.;Nguyen, Vinh H.;Lee, Hsiao-Yi
    • Current Optics and Photonics
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    • v.1 no.2
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    • pp.118-124
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    • 2017
  • Color rendering index (CRI) and luminous efficacy (LE) are two key performance factors of white LEDs (WLED). While most recent works in optics focus on methodology to improve these factors, little attention has been dedicated to chemical composition of materials. This paper studies the effect of $Sr_{2.4}1F_{2.59}B_{20.03}O_{74.8}:Eu_{0.12},Sm_{0.048}$ phosphor (SrSm), in terms of concentration and particle size on CRI and LE of 8500 K - WLEDs. Importantly, the molar mass of the componential ions in SrSm are calculated to shed light on the connection between the chemical composition of the material of interest and the performance of WLEDs. Results show that CRI can be improved to a value of around 86 by boosting red-light components in WLEDs, for all 3 major configurations: conformal, in-cup, and remote phosphor. CRI value tends to decrease with larger size of particles, while LE value goes in the reverse direction. On the other hand, both CRI and LE appear to be reduced at higher concentration of SrSm. This light attenuation is analyzed by using the Lambert-Beer law and Mie-scattering theory.

Determination of Air-dry Density of Wood with Polychromatic X-ray and Digital Detector

  • Kim, Chul-Ki;Kim, Kwang-Mo;Lee, Sang-Joon;Lee, Jun-Jae
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.6
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    • pp.836-845
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    • 2017
  • Gravimetric method is usually used to evaluate air-dry density, which is governing physical or mechanical properties of wood. Although it had high evaluation accuracy, the method is time consuming process. Thus, this study was conducted to estimate air-dry density of wood with high accuracy by using polychromatic X-ray and digital detector as alternative of gravimetric method. To quantify polychromatic X-ray projection for evaluating air-dry density, Lambert-Beer's law with the integral value of probability function was used. The integral value was used as weighting factor in the law, and it was determined by conducting simple test at various penetration depths and tube voltage. Mass attenuation coefficient (MAC) of wood also calculated by investigating polychromatic X-ray projection according to species, penetration depth and tube voltage. The species had not an effect on change of MAC. Finally, an air-dry density of wood was estimated by applying the integral value, MAC and Lambert-Beer's law to polychromatic X-ray projection. As an example, the relation of the integral value (${\alpha}$) according to penetration depth (t, cm) at tube voltage of 35 kV was ${\alpha}=-0.00091t{\times}0.0184$ while the regression of the MAC (${\mu}$, $cm^2/g$) was ${\mu}=0.5414{\exp}(-0.0734t)$. When calculation of root mean squared error (RMSE) was performed to check the estimation accuracy, RMSE at 35, 45 and 55 kV was 0.010, 0.013 and $0.009g/cm^3$, respectively. However, partial RMSE in relation to air-dry density was varied according to tube voltage. The partial RMSE below air-dry density of $0.41g/cm^3$ was $0.008g/cm^3$ when tube voltage of 35 kV was used. Meanwhile, the partial RMSE above air-dry density of $0.41g/cm^3$ decreased as tube voltage increased. It was conclude that the accuracy of estimation with polychromatic X-ray and digital detector was quite high if the integral value and MAC of wood were determined precisely or a condition of examination was chosen properly. It was seemed that the estimation of air-dry density by using polychromatic X-ray system can supplant the gravimetric method.

ETIR and Raman Spectroscopic Studies of Crystallization and Polymorphism of Syndiotactic Polystyrene (FTIR과 라만 분광 실험을 이용한 신디오탁틱 폴리스티렌의 구조 및 결정화 연구)

  • ;;;;;Kohji Tashiro
    • Polymer(Korea)
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    • v.27 no.6
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    • pp.603-608
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    • 2003
  • Syndiotactic polystyrene (s-PS) presents a very complex polymorphic behavior depending on the sample preparation history and exhibits a solid-solid phase transition. Each different polymorphic structures of the s-PS sample were prepared by annealing the samples from room temperature to 220 $^{\circ}C$. The structural changes induced by annealing were investigated using FTIR and FT-Raman spectroscopy. Although the crystallization kinetics of s-PS are difficult to investigate with DSC due to its fast crystallization rate, it was possible to determine crystallinity changes in the s-PS sample using infrared characteristic peaks with Beer-Lambert's law.

Study of Optical Tomography for Measurement of Spray Characteristics at High Ambient Pressure (고압 환경에서의 분무 특성 계측을 위한 광학 토모그래피 기법 연구)

  • Cho, Seong-Ho;Im, Ji-Hyuk;Choi, Ho-Yeon;Yoon, Young-Bin
    • Journal of the Korean Society of Propulsion Engineers
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    • v.13 no.4
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    • pp.36-44
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    • 2009
  • Spray cross-section was measured by the Optical Line Patternator (OLP) and Optical Tomography at high ambient pressure. The laser line beam passed through the spray region, then Mie scattered signal and transmitted light were captured. The measured signal was processed to obtain a distribution of attenuation coefficient in spray cross-section. Beer-Lambert's law and mathematical reconstruction methods were used to reconstruct the distribution of attenuation coefficient. Spray became dense at high pressure and attenuation of scattered signal occurred seriously. OLP method, which uses Mie scattered signal, showed limit in compensating attenuation problem in dense spray region. Optical tomography reconstructed spray cross-section well, from transmission rate of light penetrating spray region.

Chlorophyll a/b Ratio as a Criterion for the Reliability of Absorbance Values Measured for the Determination of Chlorophyll Concentration (엽록소 농도 결정을 위하여 측정한 흡광도 값의 신뢰도 검정 지표로서 엽록소 a/b 비례치)

  • Wu, Guangxi;Lee, Choon-Hwan
    • Journal of Life Science
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    • v.29 no.5
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    • pp.509-513
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    • 2019
  • The Beer-Lambert law states that absorbance is proportional to the concentration of a solute in a solution at a given wavelength. This linearity works for an ideal or a 'sufficiently diluted' solution, so this linearity is often used as a criterion for the fidelity of the absorbance value measured. In this study, we used a chlorophyll (Chl) solution, isolated from rice leaves with 80% acetone to test the use of the Chl a/b ratio as an additional criterion for checking the fidelity of measured values using four different absorption spectrophotometers: Cary4E, UV-1650PC, Versamax (a microplate reader), and NanoDrop 1,000(which can handle a $4{\mu}l$ aliquot). We used Chl solutions of varying concentrations from $0.2{\mu}g/ml$ to $200{\mu}g/ml$ to measure absorbance values at 645 nm and 663 nm and checked the linearity first. The results indicated that the range of Chl concentrations that we can rely on based on the linearity was similar to the range in which the calculated Chl concentrations based on the measured absorbance values agreed with the known concentrations. However, some border cases or cases with very low Chl concentrations inside the fidelity range of Chl concentrations did not agree with the criterion that the Chl a/b ratio should not change after dilution of the Chl in the solution. These results suggest that the Chl a/b ratio is a better criterion for the reliability of the absorbance values measured for the determination of chlorophyll concentration than the criterion based on the linearity suggested by the Beer-Lambert law.