• 제목/요약/키워드: UV detection

검색결과 548건 처리시간 0.039초

웨이블렛 에너지를 이용한 태양광 발전시스템의 단독운전 검출 기법 (Islanding Detection Technique using Wavelet Energy in Grid-Connected PV System)

  • 박해찬;김일송
    • 전력전자학회논문지
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    • 제20권5호
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    • pp.471-478
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    • 2015
  • The new islanding detection method using wavelet energy is proposed in this paper. The proposed method is based on the autocorrelation of the wavelet energies, which is obtained from the high-frequency components of the grid voltage. It has the enhanced detection capabilities in the UV/OV/UF/OF region, which the conventional passive methods cannot obtain. The mathematical theories on the wavelet are presented, and the performance effectiveness is proved by the experimental results.

유기 초박막 (CuTBP, ${Li}_{2}Pc$, ${C}_{22}$Py(TCNQ), PAAS LB막)의 ${NO}_{2}$ 가스 탐지 특성에 관한 연구 (A study on the ${NO}_{2}$ gas detection characteristics of the organic ultra-thin films (CuTBP, ${Li}_{2}Pc$, ${C}_{22}$Py(TCNQ), PAAS LB Films))

  • 김형석;유병호;조형근;한영재;김태완;김정수
    • 대한전기학회논문지
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    • 제44권4호
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    • pp.496-501
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    • 1995
  • The N $O_{2}$ gas-detection characteristics were investigated using the functional organic Langmuir-Blodgett (LB) films of Copper-tetra-tert-butylphthalocyanine (CuTBP), Dilithium phthalocyanine (Li$_{2}$Pc), N-docosylpyridinium TCNQ(C$_{22}$Py(TCNQ)), Polyamic acid alkylamine salts (PAAS). The optimum conditions for a film deposition were obtained through a study of .pi.-.ALPHA. isotherms and the deposited film status was confirmed by electrical and optical methods such as UV/visible absortion spectra, thickness measurements by ellipsometry, and electrical capacitances. A response of the LB films to the N $O_{2}$ gas was measured by a change of the electrical conductivities when the film is exposed to the gases. The CuTBP LB film shows the biggest change of the electrical conductivities when it is exposed to the N $O_{2}$ gases. And the order of gas-detection performance is the following;Li$_{2}$Pc, $C_{22}$Py(TCNQ), and PAAS LB films. Especially, the CuTBP and Li$_{2}$Pc LB films not only show the bigger change in the electircal conductivities when exposed to the gas, but return to the original state when the gas is desorbed.d.

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가시오가피(Acanthopanax senticosus)에서 polyacetylene계 화합물인 falcarinol의 동정 (Separating of Falcarinol from Acanthopanax senticosus)

  • 김성주;장규섭
    • 한국식품과학회지
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    • 제37권3호
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    • pp.360-363
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    • 2005
  • 가시오가피에서 Polyacetylene 성분 중 falcarinol을 탐색하기 위해 TLC, HPLC/PDA, GC, GC/MS를 이용하여 falcarinol 표준품과 소분획물 사이의 비교 분석을 통하여 가시오가피에서 falcarinol을 동정하였다. 가시오가피 추출물을 silica gel column상에서 용매의 극성차이에 의해 6개의 분획물을 얻었고, 6개의 분획물과 falcarinol 표준품과의 TLC 상에서 전개시킨 결과 fraction 6 분획물에서 falcarinol과 동일 band의 물질을 분리하였다. Fraction 6의 분획물과 falcarinol 표준품을 HPLC/PDA로 분석한 결과 falcarinol 표준품의 peak와 동일 retention time의 peak를 fraction 6에서 분리하여 200-340nm 상에서 UV spectrum을 관찰한 결과 동일한 UV spectrum pattern을 보이는 것을 확인하였다. 이는 전형적인 polyacetylene 화합물의 UV spectrum pattern이었으며, 기존에 보고된 falcarinol의 UV spectrum과도 동일하였다. GC로 TMS 유도체화 전,후의 retention time을 확인한 결과 표준품과 fraction 6에서 동일한 결과를 보였다. TMS 유도체화 후에는 7.5분에서 8.5분으로 약 1분 정도 retention time이 증가하였고, detection 감도 또한 증가하였다. Falcarinol 표준품과 fiaction 6 분획물을 TMS 유도체화 후에 GC/MS로 mass fragment ion을 분석한 결과 표준품과 동일한 경향을 보였고 이는 기존의 보고와도 일치하였다(16). 본 실험결과들로 미루어 가시오가피에도 polyacetylene 성분인 falcarinol 존재하는 것으로 확인되었다.

Quantitative Evaluation of Radix Astragali through the Simultaneous Determination of Bioactive Isoflavonoids and Saponins by HPLC/UV and LC-ESI-MS/MS

  • Kim, Jin-Hee;Park, So-Young;Lim, Hyun-Kyun;Park, Ah-Yeon;Kim, Ju-Sun;Kang, Sam-Sik;Youm, Jeong-Rok;Han, Sang-Beom
    • Bulletin of the Korean Chemical Society
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    • 제28권7호
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    • pp.1187-1194
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    • 2007
  • The three major active isoflavonoids (calycosin-7-O-β -glucoside, isomucronulatol 7-O-β-glucoside, formononetin) and two main saponins (astragaloside I, astragaloside IV) in an extract of Radix Astragali were determined using rapid, sensitive, reliable HPLC/UV and LC-ESI-MS/MS methods. The separation conditions employed for HPLC/UV were optimized using a phenyl-hexyl column (4.6 × 150 mm, 5 μm) with the gradient elution of acetonitrile and water as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 230 nm. The specificity of the peaks was determined using a triple quadrupole tandem mass spectrometer equipped with an electrospray ionization (ESI) source that was operated in multiple reaction monitoring (MRM) in the positive mode. These methods were fully validated with respect to the linearity, accuracy, precision, recovery and robustness. The HPLC/UV method was applied successfully to the quantification of three major isoflavonoids in the extract of Radix Astragali. The results indicate that the established HPLC/UV and LC-ESI-MS/MS methods are suitable for the quantitative analysis and quality control of multi-components in Radix Astragali.

The first UV fundamental plane and evidence of star formation in early-type galaxies

  • Jeong, Hyun-Jin;Yi, Suk-Young;Bureau, Martin;Davies, Roger L.
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.36.2-36.2
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    • 2009
  • We present GALEX (Galaxy Evolution Explorer) far (FUV) and near (NUV) ultraviolet imaging of 34 nearby early-type galaxies from the SAURON representative sample of 48 E/S0 galaxies, all of which have ground-based optical imaging from the MDM Observatory. The surface brightness profiles of nine galaxies (~26 per cent) show regions with blue UV-optical colours suggesting recent star formation. Five of these (~15 per cent) show blue integrated UV-optical colours that set them aside in the NUV integrated colour-magnitude relation. These are objects with either exceptionally intense and localised NUV fluxes or blue UV-optical colours throughout. They also have other properties confirming they have had recent star formation, in particular Hbeta absorption higher than expected for a quiescent population and a higher CO detection rate. This suggests that residual star formation is more common in early-type galaxies than we are used to believe. NUV-blue galaxies are generally drawn from the lower stellar velocity dispersion (sigma_e <200 km/s) and thus lower dynamical mass part of the sample. We have also constructed the first UV Fundamental Planes and show that NUV blue galaxies bias the slopes and increase the scatters. If they are eliminated the fits get closer to expectations from the virial theorem. Although our analysis is based on a limited sample, it seems that a dominant fraction of the tilt and scatter of the UV Fundamental Planes is due to the presence of young stars in preferentially low-mass early-type galaxies.

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이산화염소 시스템을 적용한 자율주행 방역 로봇 (Self-driving quarantine robot with chlorine dioxide system)

  • 방걸원
    • 디지털융복합연구
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    • 제19권12호
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    • pp.145-150
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    • 2021
  • 공공장소에서 지속적으로 방역을 수행하기 위해서는 인력확보가 쉽지 않은데 자율주행 기반 로봇을 활용하면 인력으로 인한 문제를 해결할 수 있다. 자율주행 기반 방역로봇은 별도의 인력 투입 없이 공공기관과 병원 등의 유해 바이러스 확산 및 질병을 지속적으로 예방 가능하다. 자율주행 기능은 피나클 필터 알고리즘을 적용하여 위치를 추정하고, 방역은 UV살균시스템 및 이산화염소 분사시스템을 적용하였다. 주행시간은 3시간 이상, 위치 오차는 0.5m.이내, 정지 회피하는 기능은 95%, 장애물 감지 거리는 1.5m에서 동작하였다, 자동충전 복구는 배터리 잔량 10%에서 충전거치대로 이동하여 충전이 되었다. 무인방역시스템으로 방역한 결과 인력배치 없이 UV살균은 99%, 이산화염소는 95% 이상 살균되어 막대한 사회적 비용을 절감하는데 자율주행 방역로봇이 기여할 수 있다.

Determination of blood concentration of higenamine by high pressure liquid chromatography

  • Park, Sun-Oak;Hong, Chang-Yee;Paik, Seung-Whan;YunChoi, Hye-Sook
    • Archives of Pharmacal Research
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    • 제10권1호
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    • pp.60-66
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    • 1987
  • A procedure utilizing high pressure liquid chroatography coupled with UV detection is described for the determination of blood concentration of higenamine. Deproteinized serum was pretreated with$C_{18}$(Sep-pak $C_{18}$ cartridge) and the 70% EtOH eluent was applied onto a reversed-phase column ($\mu$ Bondapak $C_{18}]$) with a 15% acetonitrile in 0.05 N $NaH_2$$PO_4$-trichloroacetic acid mixed buffer (pH 2.8) as a mobile phase. With the UV detection at 232 nm, the retention times of higenamine and 1, 2, 3, 4-tetrahydropapaveroline, an internal standard, were 5.2 min and 3.9 min respectively. The blood concentration of higenamine was meausred at regular intervals after i. v. injection of higenamine to rabbit. A drastic decrease in higenamine concentration to 30% of the maximum value obtained immediately after the injection, was observed during the first 1-2 min period and thereafter the rate of decrease was slowed down. The analytical result seemed to coincide with the pharmacological effect of higenamine exerting the maximum chronotropic and hypotensive effect at the completion of the injections which were progressively recovered.

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이온 크로마토그래피와 자외선 검출을 이용한 황산수용액 중의 요오드 음이온 정량 (Determination of Iodide in Sulfuric Acid Aqueous Solution by the Ion Chromatography with UV Detection)

  • 박양순
    • 분석과학
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    • 제14권4호
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    • pp.306-310
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    • 2001
  • 황상용액 매질에서 요오드 음이온을 흡착제에 흡착시킨 후 황산용액에 남아있는 요오드 음이온을 정량하기 위해 이온 크로마토그래피를 적용하였다. 산화제 작용을 하는 황산의 농도를 0.25 M, 0.5 M, 1 M로 변화시키고 요오드 음이온을 각각 첨가한 후 시간변화에 따라 요오드 음이온이 산화되는 정도를 측정하였다. 황산농도가 진할수록 요오드 음이온은 산화되어 휘발하므로 적게 검출되었다. 수산화나트륨 용액을 사용하여 환산매질을 중화하였다. 중화된 0.5 M $Na_2SO_4$ 매질 중 요오드 음이온의 농도범위가 0-20 mg/L인 구간에서 검정곡선의 직선성이 좋게 나타났다(r=0.99999).

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