• Title/Summary/Keyword: Ultraviolet detection

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Introduction of Ultraviolet/Infrared Flame Detector and Method for False Detection Prevention (자외선/적외선 불꽃감지기 소개 및 오동작 방지를 위한 연구)

  • Lim, Byung-Hyun;Ko, Nak-Yong;Hwang, Jong-Sun;Kim, Yeong-Min;Kim, Jong-Man
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05b
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    • pp.8-11
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    • 2003
  • We propose that when combustible burn with contain carbon, introduce fire detector with sensor of private-use detectable light energy as infrared and ultraviolet in energy of electromagnetic-wave type radiate from flame, method for correct discrimination to resemble fire produce false alarm of detector such as sun light, hot object radiation, are welding. This research using infrared sensor is pyroelectric infrared sensor based black body radiation theory. Ultraviolet sensor is uv Tron using gas multiplication effect to current discharge and photoelectric effect of metal. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research introduced UV/IR compound type flame detector and proposed method of false alarm reduced to resemble fire. The result propres the prevention and extinction of fire technique degree, certificated operation of detector.

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Applications of Capillary Electrophoresis and Microchip Capillary Electrophoresis for Detection of Genetically Modified Organisms

  • Guo, Longhua;Qiu, Bin;Xiao, Xueyang;Chen, Guonan
    • Food Science and Biotechnology
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    • v.18 no.4
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    • pp.823-832
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    • 2009
  • In recent years, special concerns have been raised about the safety assessment of foods and food ingredients derived from genetically modified organisms (GMOs). A growing number of countries establish regulations and laws for GMOs in order to allow consumers an informed choice. In this case, a lot of methods have been developed for the detection of GMOs. However, the reproducibility among methods and laboratories is still a problem. Consequently, it is still in great demand for more effective methods. In comparison with the gel electrophoresis, the capillary electrophoresis (CE) technology has some unique advantages, such as high resolution efficiency and less time consumption. Therefore, some CE-based methods have been developed for the detection of GMOs in recent years. All kinds of CE detection methods, such as ultraviolet (UV), laser induced fluorescence (LIF), and chemiluminescence (CL) detection, have been used for GMOs detection. Microchip capillary electrophoresis (MCE) methods have also been used for GMOs detection and they have shown some unique advantages.

Ultraviolet Lamp Replacement Period and Hygiene Management Plan of Ultraviolet Sterilizer (자외선 살균고의 자외선 램프 교체 주기와 위생관리 방안)

  • Young-Ju Lee;Ju-Hyun Lee;Eun-Sol Go;Jung-Beom Kim
    • Journal of Food Hygiene and Safety
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    • v.38 no.1
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    • pp.26-30
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    • 2023
  • In this study, we analyzed the microbial contamination level of ultraviolet sterilizer (UVS) chambers and suggested plans to improve hygiene management. In this study, UVS chambers targeted 98 UVS in some childcare centers in Jeollanam-do, Korea. Total aerobic bacteria and coliform bacteria were tested according to the Korean Food Code. Of the 98 UVS chambers, total aerobic bacteria were detected in 67 (68.4%) and coliform bacteria in 5 (5.1%). Six kinds of food-poisoning bacteria, including Salmonella spp., were not detected, but Bacillus cereus was detected in 1 (2.8%) out of 98 UVS chambers. According to the UV lamp replacement period, the detection rate of total aerobic bacteria was 3 (50%) out of 6 UVS within 3 months, 3 (60%) out of 5 UVS in 3 to 6 months, and 61 (70.1%) out of 87 UVS over 6 months. The detection rate of coliform bacteria according to the UV lamp replacement period was not detected within 6 months, however, they were detected in 5 (5.7%) out of 87 chambers after more than 6 months. The level of microbial contamination in the UVS chambers was higher as the lamp replacement period was longer. Considering these results, it was determined that the UVS chambers should be kept dry and clean, and the UV lamp should be replaced periodically. In addition, it is necessary to provide the staff catering for childcare centers with continuous education regarding the cleaning of UVS chambers and the replacement of UV lamps.

Simultaneous Determination of Glutamate, Glycine, and Alanine in Human Plasma Using Precolumn Derivatization with 6-Aminoquinolyl-N-hydroxysuccinimidyl Carbamate and High- Performance Liquid Chromatography

  • Li, Qing Zhong;Huang, Qing Xian;Li, Shu Cui;Yang, Mei Zi;Rao, Bin
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.5
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    • pp.355-360
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    • 2012
  • A simple, sensitive and reproducible high-performance liquid chromatography (HPLC) method has been validated for determining concentrations of glutamate, glycine, and alanine in human plasma. Proteins in plasma were precipitated with perchloric acid, followed by derivatization with 6-aminoquinolyl-N-hydroxysuccinimidyl carbamate (AQC). Simultaneous analysis of glutamate, glycine, and alanine is achieved using reversed-phase HPLC conditions and ultraviolet detection. Excellent linearity was observed for these three amino acids over their concentration ranges with correlation coefficients (r)>0.999. The intra- and inter-day precision were below 10%. This method utilizes quality control samples and demonstrates excellent plasma recovery and accuracy. The developed method has been successfully applied to measure plasma glutamate, glycine, and alanine in twenty volunteers.

Validation of a Simple HPLC Method for Determination of Ciprofloxacin Hydrochloride in Human Plasma (인체 혈장에서 염산시프로플록사신(시프로플록사신으로서 250 mg) 정량을 위한 HPLC 분석법의 유효성검토)

  • Ha, Yong-Hwa;Cho, Sung-Hee;Chun, Sung-Kuk;Seo, Seong-Hoon;Rew, Jae-Hwan;Choi, Young-Wook;Lee, Kyung-Tae
    • Journal of Pharmaceutical Investigation
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    • v.34 no.4
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    • pp.327-331
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    • 2004
  • A simple HPLC method with ultraviolet detection of ciprofloxacin in human plasma was developed and validated. After protein precipitation with trichloroacetic acid, chromatographic separation of ciprofloxacin in plasma was achieved at $50^{\circ}C$ with a $C_{18}$ column and methanol-phosphate mixture (pH 2.5), as mobile phase. Quantitative determination was performed by ultraviolet detection at 278 nm. The method was specific and validated with a limit of quantification of 100 ng/ml. The intra- and inter-day coefficients of variation were between 1.67% and 10.55% and accuracy between 92.01 % and 106.09%. The method has been successfully applied in a bioavailability study of 250 mg ciprofloxacin hydrochloride tablet.

Simultaneous determination of betaine and choline using derivatization by HPLC with UV detection (HPLC-UV검출방법으로 유도체화를 통한 비테인과 콜린의 동시분석)

  • Rhee, Insook;Paeng, Ki-Jung
    • Analytical Science and Technology
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    • v.28 no.2
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    • pp.112-116
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    • 2015
  • Extraction of quaternary ammonium compounds (choline and betaine) from plant samples (spinach) using ion exchange resin (AG1, OH form) is a very simple and inexpensive approach. However, it is very hard to determine amounts of choline and betaine simultaneously using high-performance liquid chromatography-ultraviolet (HPLC-UV) detection. Unlike choline, betaine has low molar absorptivity in UV-visible (UV-Vis) region, which makes it difficult to carry out UV-Vis detection of betaine. The mixture of quaternary ammonium compounds (choline and betaine) was derivatized using 2-bromo acetophenone as a derivatizing agent. As a result, choline did not react with the derivatizing agent, whereas betaine formed a betaine derivative. This betaine derivative exhibited detectable UV absorption with baseline separation between choline and the betaine derivative. Thus, with this method, choline and betaine can be determined simultaneously by using the HPLCUV method through one-step derivatization, which is an easy, sensitive, and reliable method.

FUV Images and Physical Properties of the OES region

  • Jo, Young-Soo;Min, Kyung-Wook;Seon, Kwang-Il
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.69.2-69.2
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    • 2010
  • The far-ultraviolet (FUV) H2 and C IV emission images and spectra of Orion Eridanus Superbubble (OES) is hereby presented. The OES seems to consists of multiple phase through the detection of highly-ionized gas and pervasive neutral hydrogen. The former is traced by hot gas while the latter is traced by cold medium. A spectral image made with H2 fluorescent emission shows that the spatial distribution of hydrogen molecule is well correlated with the dust map. The model spectra was taken from a photodissociation region (PDR) radiation code which find a best suitable parameter such as hydrogen density, gas temperature and incident uv intensity of the radiation field. C IV emission is caused by intermediate temperature ISM about 10^4.5 K~10^6 K. Therefore we could get more clear evidence to reveal the structure of OES. Feature of spectra for the each sub region is also presented and discussed. The data were obtained with the Far-Ultraviolet Imaging Spectrograph (FIMS) and the whole data handling were followed by previous FIMS analysis.

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FUV Images and Physical Properties of the Orion-Eridanus Superbubble region

  • Ko, Young-Soo;Min, Kyoung-Wook;Seon, Kwang-Il
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.71.1-71.1
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    • 2010
  • The far-ultraviolet (FUV) C IV and H2 emission spectra of Orion-Eridanus Superbubble (OES) is hereby presented. The OES seems to consist of multiple phase through the detection of highly-ionized gas and pervasive neutral hydrogen. The former is traced by hot gas while the latter is traced by cold medium. A spectral image made with H2 fluorescent emission shows that the spatial distribution of hydrogen molecule is well correlated with the dust map. The model spectra was taken from a photodissociation region (PDR) radiation code which finds a best suitable parameter such as hydrogen density and intensity of the radiation field. C IV emission is caused by intermediate temperature ISM about 10^5 K. Therefore we could get more clear evidence to reveal the morphology of OES. In this process, the hydrogen density and gas temperature were also estimated. The data were obtained with the Far-Ultraviolet Imaging Spectrograph (FIMS) and the whole data handling were followed by previous FIMS analysis.

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Ultraviolet and visible light detection characteristics of amorphous indium gallium zinc oxide thin film transistor for photodetector applications

  • Chang, Seong-Pil;Ju, Byeong-Kwon
    • International journal of advanced smart convergence
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    • v.1 no.1
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    • pp.61-64
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    • 2012
  • The ultraviolet and visible light responsive properties of the amorphous indium gallium zinc oxide thin film transistor have been investigated. Amorphous indium gallium zinc oxide (a-IGZO) thin film transistor operate in the enhancement mode with saturation mobility of $6.99cm^2/Vs$, threshold voltage of 13.5 V, subthreshold slope of 1.58 V/dec and an on/off current ratio of $2.45{\times}10^8$. The transistor was subsequently characterized in respect of visible light and UV illuminations in order to investigate its potential for possible use as a detector. The performance of the transistor is indicates a high-photosensitivity in the off-state with a ratio of photocurrent to dark current of $5.74{\times}10^2$. The obtained results reveal that the amorphous indium gallium zinc oxide thin film transistor can be used to fabricate UV photodetector operating in the 366 nm.

Analysis of Contact Loss Arc Spectrum between Contact Wire and Pantograph Material using a Spectrometer (광계측기를 이용한 전차선-팬터그래프 재질별 이선아크 스펙트럼 분석)

  • Chang, Chin-Young;Jung, No-Geon;Park, Jong-Gook;Koo, Kyung-Wan;Kim, Jae-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.12
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    • pp.1803-1808
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    • 2013
  • To maintain contact between catenary and pantograph copper is important in order to transmit power smoothly on Current collection system. But, Arc discharge with strong light is generated because of contact loss. Therefore, Arc discharge detection is important measurement factor judging performance of current collection system. In this paper, It is described to results of arc discharge applying UV detection technology using arc generator. And Arc discharge was detected using the most commonly used processing catenary and rigid catenary and pantograph copper of electric rolling stock for securing arc detection instrument reliability. Results of contact loss detection instrument in this paper will be used for maintenance of current collection quality and system.