• Title/Summary/Keyword: Ultra Violet

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Simulation of Target Detection using UV and IR Band Signals (UV와 IR 대역 신호를 이용한 표적 신호 검출 시뮬레이션)

  • Du, Gyeong-Su;O, Jeong-Su;Jang, Seong-Gap;Hong, Hyeon-Gi;Seo, Dong-Seon;Choe, Jong-Su
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.1
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    • pp.79-88
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    • 2001
  • The target such as aircraft operates flares to protect itself from the missile. In general, Infra-red(IR) flares that are hot bodies radiating energy considerably greater than it does, so cause the missile to guide the flare instead of the target. For a precise target tracking in spite of a presence of flares, therefore, the seeker should discriminate the target signal from various clutters including the flare and the background. In this paper, we simulated 2-color rosette scan seeker using IR and UV(UltraViolet) bands. In each wave band, we analyzed the radiant distributions of the target, the flare, and background. These results showed that a simultaneous process in two bands can detect precisely the target.

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Fabrication and characterization of optoelectronic device using CdSe nanocrystal quantum dots/single-walled carbon nanotubes (카드뮴 셀레나이드 양자점과 단일벽 탄소나노튜브로 구성된 이종 나노 소재를 기반으로 한 광전소자의 제작 및 특성평가)

  • Shim, Hyung-Cheoul;Jeong, So-Hee;Han, Chang-Soo;Kim, Soo-Hyun
    • Journal of Sensor Science and Technology
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    • v.19 no.2
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    • pp.160-167
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    • 2010
  • In this paper, we fabricated the optoelectronic device based on Cadmium selenide(CdSe) nanocrystal quantum dots (NQDs)/single-walled carbon nanotubes(SWNTs) heterostructure using dieletrophoretic force. The efficient charge transfer phenomena from CdSe to SWNT make CdSe-Pyridine(py)-SWNT unique heterostructures for novel optoelectronic device. The conductivity of CdSe-py-SWNT was increased when it was exposed at ultra violet(UV) lamp, and varied as a function of wavelength of incident light.

A Study of Far-Infrared History and Application to Physical Therapy (Far-Infrared의 발전사와 물리치료 적용에 대한 연구)

  • Kim, Jae-Yoon;Park, Rae-Joon;Park, Young-Han
    • The Journal of Korean Physical Therapy
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    • v.13 no.1
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    • pp.189-195
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    • 2001
  • The Sun's ray is composed of Infared(49%), Visible light(40%) and Ultra violet(11%), however the ray getting to the earth is FIR(60%). IR(20%), and UV(20%). Human beings has utilized FIR already from time immemorial. Hershel found out Infrared for the first time, in the Industrial Revolution the Infrared and FI R had been begun to use making products. In asia. also, asian already has made use of FIR to treat the body, product things and make warm the house in the winter, as it had been called Wull therapy, fermentation. and On-Dol system. In these days, with contemporary science FIR would be begun to clear up the implication in the human body and organic compounds. IR classified by wavelength three parts NIR, MIR, FIR. There is FIR which is radiated from healthy human body the wave length is 8-14 m. It is difficult to standardized the wavelength of IR, since each related associations have a different opinion, so we suggested ideal IR wavelength and biological, phsiotherapical, medical FIR wavelength.

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A Study on Rapid Fabrication of Micro Lens Array using 355nm UV Laser Irradiation (355nm UV 레이저를 이용한 마이크로 렌즈 어레이 쾌속 제작에 관한 연구)

  • Je, S.K.;Park, S.H.;Choi, C.K.;Shin, B.S.
    • Transactions of Materials Processing
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    • v.18 no.4
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    • pp.310-316
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    • 2009
  • Micro lens array(MLA) is widely used in information technology(IT) industry fields for various applications such as a projection display, an optical power regulator, a micro mass spectrometer and for medical appliances. Recently, MLA have been fabricated and developed by using a reflow method having the processes of micro etching, electroplating, micro machining and laser local heating. Laser thermal relaxation method is introduced in marking of microdots on the surface of densified glass. In this paper, we have proposed a new direct fabrication process using UV laser local thermal-expansion(UV-LLTE) and investigated the optimal processing conditions of MLA on the surface of negative photo-resist material. We have also studied the 3D shape of the micro lens obtained by UV laser irradiation and the optimal process conditions. And then, we made chrome mold by electroplating. After that, we made MLA using chrome mold by hot embossing processing. Finally, we have measured the opto-physical properties of micro lens and then have also tested the possibility of MLA applications.

Second harmonic generation (SHG) properties of potassium lithium niobate crystals grown by $\mu$-PD method ($\mu$-PD법에 의해 육성한 KLN단결정의 제2고조파 발생(SHG) 특성)

  • ;Tsuguo Fukuda
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.5 no.2
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    • pp.94-99
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    • 1995
  • Potassium lithium niobate (KLN) crystals, grown by the micro pulling down $({\mu}-PD)$ method, have been considered on the interchange between incongruent melt composition and second harmonic generation (SHG) properties because of the sensitive interaction. Correlation between the composition of crystals and the wavelength of SHG applications from ultra - violet to green region was found. Also, the ${\mu}-PD KLN$ KLN crystals showed a homogeneity of noncritical phase matching and an excellent SHG property which is converted to blue laser light with half wavelength by the red irradiation.

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Recent Advances in Advanced Oxidation Processes

  • Huang, Chin-Pao
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 1998.10a
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    • pp.1-1
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    • 1998
  • Advanced (Chemical) oxidation processes (AOP) differ from most conventional ones in that hydroxyl radical(OH.) is considered to be the primary oxidant. Hydroxyl radicalcan react non-selectively with a great number of organic and inorganic chemicals. The typical rate constants of true hydroxyl radical reactions are in the range of between 109 to 1012 sec-1. Many processes are possible to generate hydroxyl radical. These include physical and chemical methods and their combinations. Physical means involves the use of high energy radiation such as gamma ray, electron beam, and acoustic wave. Under an applied high energy radiation, water molecules can be decomposed to yield hydroxyl radicals or aqueous electrons. Chemical means include the use of conventional oxidants such as hydrogen peroxide and ozone, two of the most efficient oxidants in the presence of promoter or catalyst. Hydrogen peroxide in the presence of a catalyst such as divalent iron ions can readily produce hydroxyl radicals. Ozone in the presence of specific chemical species such as OH- or hydrogen peroxide, can also generate hydroxyl radicals. Finally the combination of chemical and physical means can also yield hydroxyl radicals. Hydrogen peroxide in the presence of acoustic wave or ultra violet beam can generate hydroxyl radicals. The principles for hydroxyl radical generation will be discussed. Recent case studied of AOP for water treatment and other environmental of applications will be presented. These include the treatment of contaminated soils using electro-Fenton, lechate treatment with conventional Ponton, treatment of coal for sulfur removal using sonochemical and the treatment of groundwater with enhanced sonochemical processes.

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A Estimation of Dipole Ploarization in Polypropylene Irradiated with Ultra-Violet Rays (자외선 조사된 폴리프로필렌의 쌍극자분극의 평가)

  • Kim, Sang-Keol;Jeong, Dong-Hoe;Lee, Ho-Sik;Kim, Myong-Ho;Lee, Won-Jae;Lee, Joon-Ung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.10a
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    • pp.50-55
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    • 2000
  • In this paper, Thermally Stimulated Current(TSC) spectrum has been measured in oriented polypropylene of thickness of $40{\mu}m$ which was irradiated by Ultraviolet Ray. As a result of the investigation, four peaks have been observed-two peaks ($A_1$, $A_2$) were appeared in low temperature region($-20{\sim}20^{\circ}C$) and other two peaks ($B_1$, $B_2$) in high temperature region($80{\sim}120^{\circ}C$). Among four peaks $A_1$ and $A_2$ have bee observed in detail. These peaks are shown to be created due to the polarization of diploes from the experimental results which were measured as a function forming voltage, forming time, collecting voltage and heating rate. As the increase of irradiated-time by Ultraviolet ray, the number of dipoles was increased.

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Development of UV Corona Camera for the Detecting of Discharge on Power Facility using UV Transmittance Improvement Filter (UV 투과율 향상 필터 기술을 이용한 전력설비 방전 검출용 자외선 코로나 카메라 개발)

  • Kim, Young-Seok;Choi, Myeong-Il;Kim, Chong-Min;Bang, Sun-Bae;Shong, Kil-Mok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.11
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    • pp.1656-1661
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    • 2012
  • UV inspection technology is being used for predictive maintenance of power facility together with IR-thermography and ultrasonic devices. In this paper, the UV corona camera design, fabrication, and perform a simple test to be take advantage of the diagnostic equipment. The UV corona camera developed a $6.4^{\circ}{\times}4.8^{\circ}$ of the field of view as a conventional camera to diagnose a wide range of slightly enlarged, and power equipment to measure the distance between the camera and the distance meter has been attached. The transmission between 250 to 280nm was 11% ($12.5%{\times}88%{\times}98%$) by combing the transmission on absorption film, window and other filter(UG 5, nickel sulphate and so on). In a distance of 5m with the UV corona camera it is possible to detect partial discharge with a PD level of 2.5pC and a RIV level of $3.6dB{\mu}V$.

Inter-lamina Shear Strength of MWNT-reinforced Thin-Ply CFRP under LEO Space Environment

  • Moon, Jin Bum;Kim, Chun-Gon
    • Composites Research
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    • v.30 no.1
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    • pp.7-14
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    • 2017
  • In this paper, the inter-lamina shear strength (ILSS) of multi-wall carbon nanotube (MWNT) reinforced carbon fiber reinforced plastics (CFRP) and thin-ply composites were verified under low earth orbit (LEO) space environment. CFRP, MWNT reinforced CFRP, thin-ply CFRP and MWNT reinforced thin-ply CFRP were tested after aging by using accelerated ground simulation equipment. The used ground simulation equipment can simulate high vacuum ($2.5{\times}10^{-6}torr$), atomic oxygen (AO, $9.15{\times}10^{14}atoms/cm^2{\cdot}s$), ultraviolet light (UV, 200 nm wave length) and thermal cycling ($-70{\sim}100^{\circ}C$) simultaneously. The duration of aging experiment was twenty hours, which is an equivalent duration to that of STS-4 space shuttle condition. After the aging experiment, ILSS were measured at room temperature ($27^{\circ}C$), high temperature ($100^{\circ}C$) and low temperature ($-100^{\circ}C$) to verify the effect of operation temperature. The MWNT and thin-ply shows good improvement of ILSS at ground condition especially with the thin-ply. And after LEO exposure large degradation of ILSS was observed at MWNT added composite due to the thermal cycle. And the degradation rate was much higher under the high temperature condition. But, at the low temperature condition, the ILSS was largely recovered due to the matrix toughening effect.

Deformation of a mold for large area UV-nanoimprint lithography in alignment and curing processes (UV 나노임프린트리소그래피의 정렬 공정 중 몰드의 변형해석)

  • Park, In-Soo;Won, Chong-Jin;Yim, Hong-Jae;Jeong, Jay-I.
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1939-1943
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    • 2008
  • Deformation of a mold is measured and analyzed in alignment and curing processes of UV-Imprint Lithography. We are focused on mold deformation caused by a UV resin, which is laminated between a mold and a target glass-panel. The UV resin is viscous in case of liquid state, and the resin will be solidified when being exposed by the ultra-violet light. The viscosity of the resin causes shear force on the mold during the alignment process. Moreover, the shrinkage during phase change from liquid to solid may cause residual stress on the mold. The experiments for measuring temperature and strain are made during alignment and curing process. Strain-gages and thermocouples are used for measuring the strain and variation of temperature on several points of the mold, respectively. The deformation of mold is also simulated and analyzed. The simulation results are compared with the experiments. Finally, sources of alignment errors in large area UV-nanoimprint lithography are discussed.

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