• Title/Summary/Keyword: Detector materials

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Analysis of Heavy Metals, Sulfur Dioxide and Residual Pesticides in Oriental Medical Materials at a Certain Oriental Medical Hospital (모 한방병원 한약재내 중금속과 이산화황 함량 및 잔류농약 분석 연구)

  • Cho, Woong-Hee;Cha, Yun-Yeop;Baik, Tai-Hyun;Kim, Byoung-Woo;Lee, Seung-Gi;Yoo, Jun-Sang;Sohn, Young-Joo;Sun, Seung-Ho
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.3
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    • pp.489-495
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    • 2011
  • The purpose of this study was to analyze harmful heavy metals, sulfur dioxide and residual pesticides in 30 kinds of oriental medical materials. This study was carried out on 30 samples of oriental medical materials. The examination's methods fallow the guideline of Food and Drug Administration. Inductively Coupled Plasma Mass Spectrometer (ICP-OES) was used to analyze lead, arsenic, cadmium. Mercury was analyzed by amalgamation method. A modified Monier-Williams method was used to analyze sulfur dioxide. The Gas Chromatography / Electron Capture Detector (GC/ECD) was used to analyze residual pesticides. Most of the results were within normal limits at baseline. but Cadmium was detected 0.523 mg/kg more than 0.3 mg/kg in Cinnamomi ramulus and Endosulfan was detected 11.595 mg/kg more than 0.2 mg/kg in Alismatis rhizoma. We needs to keep the quality of herbal medicines assessing and controling for safety of herbal medicines.

Label-free Femtomolar Detection of Cancer Biomarker by Reduced Graphene Oxide Field-effect Transistor

  • Kim, Duck-Jin;Sohn, Il-Yung;Jung, Jin-Heak;Yoon, Ok-Ja;Lee, N.E.;Park, Joon-Shik
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.549-549
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    • 2012
  • Early detection of cancer biomarkers in the blood is of vital importance for reducing the mortality and morbidity in a number of cancers. From this point of view, immunosensors based on nanowire (NW) and carbon nanotube (CNT) field-effect transistors (FETs) that allow the ultra-sensitive, highly specific, and label-free electrical detection of biomarkers received much attention. Nevertheless 1D nano-FET biosensors showed high performance, several challenges remain to be resolved for the uncomplicated, reproducible, low-cost and high-throughput nanofabrication. Recently, two-dimensional (2D) graphene and reduced GO (RGO) nanosheets or films find widespread applications such as clean energy storage and conversion devices, optical detector, field-effect transistors, electromechanical resonators, and chemical & biological sensors. In particular, the graphene- and RGO-FETs devices are very promising for sensing applications because of advantages including large detection area, low noise level in solution, ease of fabrication, and the high sensitivity to ions and biomolecules comparable to 1D nano-FETs. Even though a limited number of biosensor applications including chemical vapor deposition (CVD) grown graphene film for DNA detection, single-layer graphene for protein detection and single-layer graphene or solution-processed RGO film for cell monitoring have been reported, development of facile fabrication methods and full understanding of sensing mechanism are still lacking. Furthermore, there have been no reports on demonstration of ultrasensitive electrical detection of a cancer biomarker using the graphene- or RGO-FET. Here we describe scalable and facile fabrication of reduced graphene oxide FET (RGO-FET) with the capability of label-free, ultrasensitive electrical detection of a cancer biomarker, prostate specific antigen/${\alpha}$ 1-antichymotrypsin (PSA-ACT) complex, in which the ultrathin RGO channel was formed by a uniform self-assembly of two-dimensional RGO nanosheets, and also we will discuss about the immunosensing mechanism.

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An Experimental Study of the Pulse Tube Cryocooler with the Linear Compressor (초전도 필터 냉각용 선형압축기형 맥동관 냉동기의 실험적 연구)

  • 박성제;홍용주;김효봉;고득용;염한길;김양훈;김종학
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2002.02a
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    • pp.197-201
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    • 2002
  • A free piston and free displacer (FPFD) Stirling cryocooler and inertance pulse tube cryocooler for the cooling infrared detector and cryosensor are currently under development at Korea Institute of Machinery & Materials. The pulse tube cryocooler, which has no moving parts at its cold section, is attractive for obtaining higher reliability, simpler construction and lower vibration than in any other small cryocoolers. In recent years, pulse tube cryocoolers have experienced a rapid development with the aim to eventually replace Stirling and Gifford-McMahon cryocoolers in various applications. In this study, operating characteristics of the conventional linear Stirling cryocooler was investigated by experiment. And, inertance pulse tube cryocooler with the commercial linear compressor(Leybold Polar) was designed, manufactured, and tested by the variations of the operating frequency, charging pressure and input power.

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A Study on Display Data of Radiation Point at 3 Dimensions (3차원 공간상 방사선원 위치 정보 표현에 관한 연구)

  • Lee, Seung-Min;Lee, Heung-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.6
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    • pp.1130-1132
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    • 2007
  • In this research, 3D position exploring system was developed to detect direction and position of radiation source by using two general CCD camera. This system consists of a radiation detection device, a controlling device, and a monitoring device. A radiation detection device is composed of a collimator, a scintillator, CCD sensor, and radiation shielding part. Incident radiation is firstly collimated with direction and converted into visual lights in a scintillator. The CCD sensor detect the converted visual light and send a signal as an image. This can explore a radiation source with direction and distance from geometrical structure of two sensors. From these information, the developed 3D position exploring system can provide 3D radiation source information. This research will be useful for managing and processing radioactive materials in remote.

Study in Background Reduction for the Neutron Induced Prompt Gamma-ray Spectroscopy

  • Song, Byoung-Chul;Jee, Kwang-Yong;Park, Yong-Joon
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2004.06a
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    • pp.433-433
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    • 2004
  • Neutron induced prompt gamma-ray spectroscopy (NIPS) system measures the prompt gamma-ray, emitting by the interaction of a neutron with various materials. This system will be of great benefit to scientists worldwide, since it provides the non-destructive measurement of many elements in either solid or liquid wastes. A NIPS facility has been developed in Nuclear Chemistry Research Division, at Korea Atomic Energy Research Institute (KAERI) with the aim of analyzing the major component elements in both aqueous and solid samples.(omitted)

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5% $Cr_2O_3/{\gamma}-Al_2O_3$ Catalysts Synthesized as Research for Oxidation Activation of Trichloroethylene

  • Myung, So-Young;Suh, Myung-Gyo;Lee, Yong-Hee
    • Proceedings of the Korean Environmental Health Society Conference
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    • 2005.12a
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    • pp.78-82
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    • 2005
  • The research addressed the ability of 5% $Cr_2O_3/{\gamma}-Al_2O_3$ to catalytically oxidize trichloroethylene(TCE). In order to determine which procedure gives the most active catalyst among the attempted several procedures, catalytic oxidation reaction of TCE was conducted to every catalysts synthesized according to different process in tubular reactor system, which had functional relationships with temperature and space velocity. The ratio of TCE conversion was analyzed by gas chromatography with electron capture detector.

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Study for the Preparation of Deodorizing Fiber( III ) - Preparations of Deodorizing Fibers using $TiO_2$ and Effects of $TiO_2$ sol Concentration on the Deodorant Activity- (소취 섬유의 제조에 관한 연구(III) - 산화티탄(IV)을 이용한 소취 섬유의 제조 및 $TiO_2$ sol 용액의 농도가 소취율에 미치는 영향 -)

  • 박수민;오선화;강영수
    • Textile Coloration and Finishing
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    • v.14 no.3
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    • pp.11-18
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    • 2002
  • The preparations of deodorizing fibers using $\textrm{TiO}_2$ have been investigated. $\textrm{TiO}_2$ is known to be an excellent photocatalyst for the degradation of organic and inorganic contaminants in water. $\textrm{TiO}_2$ catalyst have been supported on the glass fiber by a dip-coating procedure. The resulting materials have been characterized by XRD and SEM. The immobilized catalysts were tested in the photocatalytic degradation of $\textrm{NH}_3$, $\textrm{CH}_3\textrm{SH}$ and $\textrm{CH}_3\textrm{CHO}$. The deodorant activity(D.A.) of these deodorizing fibers was measured by chromogenic gas detector tubes. The efficient deodorant activity results have been achieved through the increase of $\textrm{TiO}_2$ sol concentration.

The Research & Development of Infra-Red Flame Detector (적외선 불꽃감지기 개발연구)

  • 이복영;권오승;정창기;박상태;조성수
    • Fire Science and Engineering
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    • v.14 no.2
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    • pp.1-6
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    • 2000
  • The radiant energy from a flaming fire of fuels containing carbonaceous material can be applied to fast growing fire. Raiant energy sensinsing technique applied detectors are ultimately effective when early detecting fire alarm system is required or the smoke and heat detectors can not be applied. This study investigated the characteristics of sun light, artificial light and flame radiation light and the foundation technique of flame detecting is established. Pyroelectric element proper for the characteristics of flame radiant energy developed and circuit stabilizing technique, electro-magnetic immunity technique, durable and reliable operating technique to circuits developed.

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Penetration depth and Wave Propagation in Random Media (무질서한 매질에서 침투깊이와 파동 전파)

  • Kim, Ki-Jun;Sung, Ki-Chun
    • Journal of the Korean Applied Science and Technology
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    • v.23 no.1
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    • pp.70-76
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    • 2006
  • The influence of fluorophor, scatterer, absorber in turbid materials by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it is studied the molecular property by laser induced fluorescence spectroscopy. It can be found that the effects of optical property are penentrated in scattering media by the optical $parameters({\mu}s$, ${\mu}a$, ${\mu}t$, ${\gamma}$, ${\rho})$. The value of scattering coefficient ${\mu}s$ is large appeared by means of the increasing particles of scattering, it can be found that the slope appears exponentially as a function of distance from laser source to detector. It may also utilize in designing the best model for oil chemistry, laser medicine and application of medical engineering.

Noise properties of the PSS-PT-PZ pyroelectric infrared detector (PSS-PT-PZ초전형 적외선 검출기의 잡음특성)

  • 우승일;류기원;이성갑;이성희
    • Electrical & Electronic Materials
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    • v.6 no.6
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    • pp.573-581
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    • 1993
  • 0.10Pb(Sb$_{1}$2/Sn$_{1}$2/)O$_{3}$-0.25PbTiO$_{3}$-0.65PbZrO$_{3}$ 세라믹을 소결온도 및 시간을 각각 1200-1250[.deg.C]에서 2, 4, 6시간으로 변화시켜 제작하였으며 시편의 소결조건 및 MnO$_{2}$(0~0.30mol%)첨가량에 따른 잡음특성을 관찰하였다. 초전계수 및 전압감도는 1250[.deg.C]에서 2시간 소결시킨 시편에서 각각 3.49x$10^{-8}$[C/$cm^{2}$K], 147[V/W]의 최대값을 나타내었다. 초전형 적외선 검출기의 잡음특성에 있어 증폭기의 전류잡음 .DELTA.V$_{i}$가 총 잡음전압에 대해 지배적인 경향을 나타내었으며 MnO$_{2}$가 0.24[mol%] 첨가된 1250[.deg.C]에서 2시간 소결시킨 시편에서 가장 양호한 pop-corn잡음특성을 나타내었다.다.

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