• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05c
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• pp.31-35
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• 2004

We propose driving method of Ultraviolet sensor for fire alarms using pulse width modulation that used to fire detector with sensor of private-use detectable light energy as ultraviolet in energy of electromagnetic-wave type radiate from flame, when combustible burn with contain carbon,. 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 designed driving circuit with UV sensors and proposed method of false alarm reduced to resemble fire. the result propers the prevention and extinction of fire technique degree, certificated operation of detector.

• Journal of the Korean Chemical Society
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• v.37 no.4
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• pp.453-461
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• 1993

Detection method was developed using a simply designed photochemical reactor made of teflon coil and low pressure mercury lamp. This method of UV photolysis of analytes followed by UV, fluorescence and electrochemical detection was found to be useful for four thiocarbamates. Analytes eluting from the column are irradiated with a high flux of 254 nm UV light, so that they change to either fluorescent active forms or highly electrochemically sensitive products. Appling this technique to the UV detection, thiocarbamates were converted into long wavelength absorbing products upon UV irradiation. In fluorescence detector four thiocarbamates are not detected at nonirradiated condition but fluorescence signals of MPTC, CPTC photolysates are appeared after irradiation with UV light. The electrochemical detection for the determination of thiocarbamates was enhanced up to 5∼20 fold signal after UV irradiation, compared to that of the nonirradiated. The detection limit of thiocarbamates on electrochemical detector was 13.3∼0.02 ng under pH 7.0, ionic strength $0.5{\times}10^{-2}$ M, phosphate buffer solution. Adducts produced by reaction of photolysates and OPA-MERC in the reaction coil were monitored at 425 nm with fluorescence detector, and one of the photolysates was primary amine.

• Journal of the Institute of Electronics Engineers of Korea TE
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• v.42 no.3
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• pp.45-50
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• 2005

A UV camera is being used in various application regions such as industry, medical science, military, and environment monitoring. A ROIC(ReadOut IC) is developed and can read the responses from UV photodiode sensors which are made with III-V nitride semiconductors of GaN series haying high resolution and high efficiency. To design FPA(Focal Plane Array) UV $8{\times}8$ ROIC, the photodiode type sensor devices are modeled as the capacitor type ones. The ROIC reads out signals from the detector at)d outputs sequentially pixel signals after amplifying and noise filtering of them. The ROIC is fabricated using the $0.5{\mu}m$ 2Poly 3Metal N-well CMOS process. And then, it and photodiode array are hybrid bonded by gold stud bumping process using ACP(Anisotropic Conductive Paste). After the packaging, UV images appearing on PC verified the operations of the ROIC.

• Food Science and Preservation
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• v.22 no.4
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• pp.553-558
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• 2015

The aims of this study was to optimize the extraction conditions of sinigrin from Dolsan leaf mustard. Dolsan leaf mustard (Dolsan-eup, Yeosu-si) harvested during at May 2014 was used for sinigrin extraction. After the extraction of sinigrin using 50% $CH_3CN$, 10% $NH_4Cl$, 60% $CH_2OH$, and 70% $CH_3OH$, the sinigrin content was measured by HPLC analysis. The results showed that sinigrin content was highest with 50% $CH_3CN$ solvent extraction and UV detector sensitivity was greater at 228 nm rather than at 242 nm. The sinigrin concentrations of leaf, stem and root with 50% $CH_3CN$ extraction were 345 ppm, 728 ppm, and 539 ppm, respectively. After extraction of the different parts of Dolsan leaf mustard, The standard retention time by HPLC analysis of sinigrin content was 2.054, 2.032, 2.059, and 2.035 min from the root, stalk, and leaf, respectively. On the other hand, HPLC analysis showed that the leaf extracts contained glucoraphanin, one of glucosinolates. The optimum time and extraction solvent for the sinigrin extraction from Dolsan leaf mustard was found to be 24 hr with 50% $CH_3CN$ solvent. In addition, opotimum UV detector k at 228 nm. These results showed that the optimum extraction conditions for Dolsan leaf mustard were 24 hr extraction with 50% $CH_3CN$ solvent. In addition, the optimum wavelength of UV detector was determined to be 228 nm for sinigrin analysis. Therefore, this study could provide a useful information for sinigrin extraction and its systematic analysis during the storage.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.303-310
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• 2005

This study was performed to examine analytical method of a quinolone compound, oxolinic acid in paddy soil by HPLC coupled with UV detector. Two types of soil texture in different regions were used for this experiment. Oxolinic acid was extracted by a 4 M-KOH : MeOH(1 : 3, v/v) mixtures and acidified followed by liquid-liquid partitioning in dichloromethane. Dichlormethane layer was dehydrated, evaporated and analyzed by HPLC (262 nm). Retention time was 10.2 min. The standard calibration curve of oxolinic acid showed linearity ($r^2>0.999^{**}$, y=378.99x+135.08) in the range of $1{\sim}40$ ng. The mean recoveries, evaluated from fortified soil samples at two concentration levels of 0.2 mg/kg and 1.0 mg/kg, were $90.9{\pm}4.52%$(C.V. 4.97%) and $95.0{\pm}0.23%$(C.V. 0.24%) for soil 1 and $92.2{\pm}1.15%$(C.V. 1.25%) and $93.1{\pm}0.31%$ (C.V. 0.33%) for soil 2, respectively The detection limits of two types of soils were same as 0.05 ppm. Overall, the present analytical method of oxolinic acid by HPLC coupled with UV detector seems to be used reasonably.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.3
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• pp.503-510
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• 2006

Readout circuit is to convert signal occurred in a defector into suitable signal for image signal processing. In general, it has to possess functions of impedance matching with perception element, amplification, noise reduction and cell selection. It also should satisfies conditions of low-power, low-noise, linearity, uniformity, dynamic range, excellent frequency-response characteristic, and so on. The technical issues in developing image processing equipment for focal plane way (FPA) can be categorized as follow: First, ultraviolet (UV) my detector material and fine processing technology. Second, ReadOut IC (ROIC) design technology to process electric signal from detector. Last, package technology for hybrid bonding between detector and ROIC. ROIC enables intelligence and multi-function of image equipment. It is a core component for high value added commercialization ultimately. Especially, in development of high-resolution image equipment ROIC, it is necessary that high-integrated and low-power circuit design technology satisfied with design specifications such as detector characteristic, signal dynamic range, readout rate, noise characteristic, ceil pitch, power consumption and so on. In this paper, we implemented a $8\times8$ FPA prototype ROIC for reduction of period and cost. We tested unit block and overall functions of designed $8\times8$ FPA ROIC. Also, we manufactured ROIC control and image boards, and then were able to verify operation of ROIC by confirming detected image from PC's monitor through UART(Universal Asynchronous Receiver Transmitter) communication.

• Journal of Soil and Groundwater Environment
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• v.14 no.6
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• pp.35-44
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• 2009

Naphthalene and TNT (2,4,6-trinitrotoluene) are defined by U.S. EPA as possible carcinogenic compounds known to have detrimental effects on the aquatic ecosystem and human body. There are, however, few researches on methods of analyzing micro-levels of naphthalene and TNT dissolved in groundwater. This study introduces and evaluates the newly developed analytical methods of measuring naphthalene and TNT in groundwater by using HPLC-FLD (Fluorescence detector) and MSD (Mass detector). The MDL, LOQ and salt effect of these methods, respectively, are compared with those of conventional methods which use HPLC-UV. For the analysis of naphthalene, HPLC-FLD was set in the maxima wavelength (Ex: 270 nM, Em: 330 nM) obtained from 3D-Fluorescence to be compared with HPLC-UV in 266 nM wavelength. The MDL ($0.3\;{\mu}g/L$) and LOQ ($2.0\;{\mu}g/L$) of naphthalene by using HPLC-FLD were approximately 80 times lower than those analyzed by HPLC-UV (MDL: $23.3\;{\mu}g/L$, LOQ: $163.1\;{\mu}g/L$). HPLC-MSD were used in comparison with HPLC-UV in 230 and 254 nM wavelength for the analysis of TNT. The MDL ($0.13\;{\mu}g/L$) and LOQ ($0.88\;{\mu}g/L$) of TNT analyzed by using HPLC-MSD were approximately 130 times lower than those obtained by using HPLC-UV in 230 nM (MDL: $16.8\;{\mu}g/L$, LOQ: $117.5\;{\mu}g/L$). The chromatogram of TNT analyzed by using HPLC-UV in 230 nM displayed elevated baseline as the concentration of ${NO_3}^-$ increases beyond 21 mg/L, while the analysis using HPLC-MSD did not demonstrate any change in baseline in presence of ${NO_3}^-$ of 63.7 mg/L which is 3.5 times higher than average concentration in groundwater. In conclusion, HPLC-FLD and HPLC-MSD may be used as suitable methods for the analysis of naphthalene and TNT in groundwater and drinking water. These methods can be applied to the monitoring of naphthalene and TNT concentration in groundwater or drinking water.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.28-32
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• 1998

Two organophosphorous insecticides, Dichlorovos and Chloropyrifos were degraded in the presence of UV irradiation, UV irradiation with $TiO_2$ powder and UV irradiation with sea sand using low pressure mercury lamp. The identification of these compounds was carried out by gas chromatograph with a nitrogen-phosphorous detector, Total Organic Carbon and Ion Chromatograph, respectively. Both dichlorvos and chloropyrifos, UV irradiation with sea sand were more degradable than UV irradiation and UV irradiation with $TiO_2$ powder. The final products were $Cl^-$ in Dichlorvos, $Cl^-$ $SO_4{^{2-}}$ in Chloropyrifos, respectively.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1028-1032
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• 2003

To assess accurate methods for measuring sulfur dioxide residue in pickles, the acid distillation HPLC-UV method and Monnier Willams modified method were examined. By the acid distillation HPLC-UV method, sulfites released from pickles by acid distillation were absorbed in 1% triethanolamine solution and detected as sulfite ion by HPLC with UV monitoring at 240nm. An anion exchange column was employed with 1.8mM $Ma_2CO_3-1.7mM\;NaHCO_3$ solution as a mobile phase, $84.0{\sim}91.7%$ of sulfite added to pickled radish were recovered. Total sulfite levels from 48 kinds of pickles analyzed by acid distillation HPLC-UV was compared with those analyzed by the Monnier Williams modified method. The Monnier Williams modified method showed higher levels of sulfur dioxide than the acid distillation HPLC-UV method due to the presence of volatile acids in pickles. The concentration of sulfur dioxide was in the range of $N.D{\sim}173.05ppm$ in pickled radish and over 30ppm of sulfur dioxide from 3 samples by the acid distillation-HPLC-UV method.

• Journal of environmental and Sanitary engineering
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• v.7 no.1
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• pp.79-86
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• 1992

Rapid determination of chlorpyrifos and fluvalinate in mixed insecticide was established by using high performance liquid chromatography. Result were as follows : 1. On Lichrosorb${\circledR}$ RP-8(10 ${\mu}m$) Column with on fluent of acetanitrile : water=75 . 25, sufficient separation of Chlorpyrifos and Fluorinate of base was obtained. 2.410td portion the diluted solution was injected in to the cdumn, and the effluent was monitored by on UV-Detector at 270 nm. 3. Relative Standard Deviation were 0.97% (chlorpyrifos) and 0.5% (fluorinate) under analysis conditions. 4. The UV-Detector response at 270 nm were linear (Y=421.8X-2090, $R^2=0.9997$ : Chlorpyrifos, Y= 1062.7X-4017.7, $R^2=0.9998$ : Fluorinate) over a range of 30~500 ${\mu}g/ml$.