• Title/Summary/Keyword: Absorption property

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Modeling the optical properties of phytoplankton and their influence on chlorophyll estimation from remote sensing algorithms

  • Zhou, Wen;Cao, Wen-Xi
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.479-482
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    • 2006
  • The absorption coefficient and backscattering properties of phytoplankton were calculated from the Mie theory. Given a simple case that phytoplankton and mineral particles are the only constitutions in seawater, the reflectance $b_b({\lambda})/[a({\lambda})+b_b({\lambda})]$was analyzed. Then the chlorophyll concentrations were estimated from remote sensing OC2 algorithm. The results show that reflectance in short wavelength region is more sensitive to the Chl variation; High mineral concentrations in seawater have significant influence on the reflectance spectrum; the existence of high mineral concentration may result in the mistake in chlorophyll estimation from OC2 algorithm.

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Development of RAM in Millimeter Wave Range for RF Stealth (RF 스텔스 효과를 위한 밀리미터 RAM 개발)

  • Choi, Chang-Mook;Lim, Bong-Taeck;Ko, Kwang-Soob
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.6
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    • pp.1241-1246
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    • 2009
  • In this paper, stealth technology, which minimizes detection from the enemy, was analyzed and it was confirmed that Most RCS reduction comes from shaping and in specific parts, by applying RAM. Therefore, we designed and manufactured RAM that absorbs 98% of electromagnetic wave at 94 GHz with 17dB of radar absorption property to minimize RCS at milimeter wave range. As a result, we had 62% reduction in the detection range from the enemy by using developed RAM.

Synthesis and Optical Characterization of 1,1-bis(trisilyl)tetraphenylsilole (1,1-Bis(trisilyl)tetraphenylsilole의 합성 및 광학적 특성)

  • Lee, Sung Gi;Kim, Bumseok
    • Journal of Integrative Natural Science
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    • v.2 no.2
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    • pp.73-77
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    • 2009
  • Silyl-containing tetraphenylsilole, 1,1-bis(trisilyl)tetraphenylsilole, has been synthesized from the reaction of dichlorotetraphenylsilole and dichlorotrisilane and characterized by using NMR spectroscopy. Bis(trisilyl)tetraphenylsilole exhibits an unusual optical property and its optical property was characterized by UV-vis and fluorescence spectroscopy. Absorption wavelength maxima of bis(trisilyl)tetraphenylsilole was 380 nm. Bis(trisilyl)tetraphenylsilole displayed an emission band at 530 nm with an excitation wavelength of 380 nm.

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Density and Thermal Conductivity Property of the Lightweight Composite Panel Core According to Pearlite Replacement ratio (펄라이트 치환율에 따른 경량복합패널 심재의 밀도 및 열전도율 특성)

  • Kim, Heon-Tae;Jung, Byeong-Yeol;Lee, Sang-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2014.11a
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    • pp.175-176
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    • 2014
  • Recently, in the apartment house of our country, office building, apartment, and etc, the lightweight composite panel is much used as the partition wall body. This is due to be very convenient when the execution and dismantling is convenient and it forms the space which the consumer in the space desires. Therefore, in this research, the thermal conductivity property of the lightweight composite panel core according to the replacement ratio variation of the pearlite tries to be analyze. As the density test result and replacement ratio of the pearlite increased, the density showed the tendency to rise. the replacement ratio of the pearlite increased, the absorption rate showed the tendency to fall. And this is determined that absorption rate is degraded due to the increase in the density. the thermal conductivity test result and pearlite replacement ratio increased, the tendency that the thermal conductivity increases was represented.

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Compressive Strength Property of Cement Matrix According to the Type of Lightweight Aggregate (경량골재의 종류에 따른 시멘트 경화체의 강도 특성 평가)

  • Pyeon, Myeong-Jang;Jeong, Su-Mi;Kim, Ju-Sung;Kim, Ho-Jin;Park, Sun-Gyu
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.04a
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    • pp.111-112
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    • 2022
  • Lightweight aggregate is a porous material that has a lower density than natural aggregate and is a lightweight construction material. Lightweight Aggregate has a suitable purpose because it is effective in reducing the heavy unit mass in high-rise buildings. However, since lightweight aggregate has weak strength and high water absorption compared to natural aggregate, it is difficult to control the quality of concrete. Although lightweight aggregate has disadvantages such as high water absorption, it is expected that the demand for lightweight aggregate concrete will continue to use in the future because the advantage of being able to reduce the weight of concrete is greater. In this study, we conducted an experimantal study on the compressive strength property of cement matrix according to the type of lightweight aggregate.

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Experimental investigation of the effect of the addition of Aerosil 200 nanoparticles on the water absorption of polymer concrete

  • A.M. Fattahi;Babak Safaei;Elham Moaddab;Zahra Pezeshki
    • Advances in nano research
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    • v.14 no.1
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    • pp.81-92
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    • 2023
  • In this work, the effect of the addition of Aerosil 200, an insulating resin applied in many industries, on the water absorption of cement plast mixture has been experimentally evaluated. First, the preparation stages of cement plast mixture was evaluated based on corresponding standards and then, the effect of the addition of Aerosil 200 nanoparticles (NPs) to cement plast mixtures with sand weight percentage range of 0-0.1% on the variation of water absorption properties was evaluated based on National Standard Institution of Iran 20185 for Concrete Flooring Blocks - Requirements and Test Procedures. Based on the obtained results, it could be found that excessive addition of NPs did not affect the physical properties of the final product. Water absorption percentage was increased in the weight percentage of cement. By the increase of the amount of Aerosil 200 NPs in the prepared cement plast mixture, the percentage of water absorption in weight percentage of sand was decreased. Cement plast with NPs presented significantly lower water absorption than that without NPs.

Formulation and Evaluation of Loxoprofen Plasters (록소프로펜 플라스터의 제제설계 및 평가)

  • 김태성;전인구
    • Biomolecules & Therapeutics
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    • v.9 no.4
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    • pp.298-306
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    • 2001
  • To develop a novel transdermal delivery system of loxoprofen (LP), a potent antiinflammatory and analgesic agent, the effects of vehicle composition and drug loading dose on the skin permeation property were investigated. And in vivo skin absorption property studied by analysing the $C_{max}$ and AUC was investigated after applying the developed plaster systems on rabbit back skin. Addition of isopropyl myristate (IPM) and IPM-diethylene glycol monoethyl ether (DGME) cosolvent in the plaster showed higher permeation rates than those from propylene glycol laurate-DGME cosolvent systems. As the concentration of LP in the plaster increased from 0.56 mg/$\textrm{cm}^2$ to 1.19 mg/$\textrm{cm}^2$, the drug release and skin permeation rates increased linearly. At loading dose of 1.19 mg/$\textrm{cm}^2$, the flux reached 35.6 $\mu$g/$\textrm{cm}^2$/hr. New LP plasters showed a good adhesive property onto skin, and showed no crystal formation. The AU $C_{0-24hr}$ and $C_{max}$ after dermal application of LP plaster (60 mg/70 $\textrm{cm}^2$) were found to be 6951$\pm$230 ng.hr/ml and 400$\pm$44 ng/ml, respectively. And the plasma concentration maintained above 300 ng/ml up to 24 hr period. In the carrageenan-induced rat paw edema test, LP plaster showed similar inhibition rate with marketed ketoprofen (Ketoto $p^{R}$) plaster.aster.r.

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Enhancing photoluminescence of Au - TiO2 nanoparticles using Drude model

  • Dang, Diem Thi-Xuan;Vu, Thi Hanh Thu
    • Journal of IKEEE
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    • v.21 no.3
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    • pp.288-296
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    • 2017
  • The enhancement of photoluminescence of Au-$TiO_2$ nanoparticles by surface plasmon resonance has been studied extensively by experiment in recent years. For the purpose of optimizing the photoluminescence property of Au-$TiO_2$ nanoparticles, the manufacturing parameters related to the Au nanoparticles and $TiO_2$ nanoparticles need to be considered. In this paper, Drude model and Maier's effective volume method are used to analyze the variation of the metal nanoparticle radius, separation between metal nanoparticle and dielectric molecule, and total absorption cross-section with original radiative efficiency on the photoluminescence property of Au-$TiO_2$ nanoparticles. The results show that to obtain the optimized enhancement factor for photoluminescence process, the size of Au nanoparticle is about 13 - 20 nm, the separation between Au nanoparticle and $TiO_2$ molecule is about 5 -15 nm, the total absorption cross-section of $TiO_2$ molecules is about $1-100nm^2$ and the original radiative efficiency of $TiO_2$ molecule is weak about 0.001- 0.1. With these fabrication parameters, the photoluminescence property of Au-$TiO_2$ nanoparticles can be enhanced several thousand times compared to traditional $TiO_2$ nanoparticles.

Development of EM Wave Absorber for Hi-pass System Using Amorphous Metal Powder

  • Kim, Dong-Il;Yoo, Gun-Suk;Choi, Dong-Soo
    • Journal of Navigation and Port Research
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    • v.35 no.9
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    • pp.717-720
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    • 2011
  • In this paper, we designed and fabricated the Electromagnetic(EM) wave absorber for an Electronic Toll Collection(ETC or Hi-pass) system by using Amorphous metal powder and CPE. The material properties and the absorption properties of the samples containing 50 wt.%, 60 wt.%, 70 wt.%, and 80 wt.% of Amorphous. Moreover, the EM wave absorption abilities were simulated for the different thicknesses of the EM absorbers by adopting the measured permittivity and permeability, and then the EM wave absorber was fabricated based on the simulated design values. As a result, the EM wave absorber with the composition of Amorphous metal powder : CPE = 50 : 50 wt.% with the thickness of 2.6 mm has excellent absorption ability more than 40 dB at 5.8 GHz.