• 센서학회지
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• 제8권6호
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• pp.427-433
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• 1999

본 논문은 페라이트 코어, 여자코일과 픽업코일로 구성된 1축 fluxgate 마그네틱 센서를 제안하였다. 본 마그네토미터는 검출소자, 여자코일을 위한 드라이브 회로, 픽업코일 출력으로부터 DC 자장에 비례한 제 2고조파 성분검출을 위한 신호처리 회로로 구성하여 회로를 설계하고 제작하였다. 코어는 82회의 여자코일을 통해 구형파전압으로 여자하였다. 픽업 코일(150 회)의 제 2고조파 출력은 FFT 스펙트럼 분석기로 측정하였으며, 그 결과를 제 2 고조파 성분 검출을 위한 PSD(phase sensitive detector)단의 출력과 비교하였다. 감도는 구동주파수 2 (kHz)에서 약 50 [V/T]의 결과를 얻었으며, fluxgate 마그네틱 센서의 비선형계수는 약 2.0% 정도였다.

• Bulletin of the Korean Chemical Society
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• 제19권5호
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• pp.524-526
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• 1998

A sensitive and specific method is described for the determination of midazolam in human plasma. The drug was extracted from 1 mL of carbonate buffered plasma (pH 9.6) with 8 mL of diethyl ether. Famprofazone was used as internal standard. The organic phase was evaporated to dryness. The residue was dissolved in methanol for the direct analysis by gas chromatograph-nitrogen phosphorus detector system. In the concentration range of 1-5000 ng/mL, the calibration curve was linear. The coefficients of variation from the precision test were <6% at the range of the concentration of 0.10-2.00 μg/mL and the detection limit for midazolam in 1 mL of plasma was o.5 ng. This assay is more sensitive, selective, simple and rapid than earlier methods. Plasma midazolam concentrations were determined by this method after administration of midazolam.

• Biomolecules & Therapeutics
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• 제16권2호
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• pp.168-172
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• 2008

The present study is to determine of sensitive nicorandil analysis method using HPLC and measure the pharmacokinetics parameters (bioavailability, $C_{max}$, $T_{max}$, Ke, $T_{1/2}$) of nicorandil (5 mg, Tab; Choongwae Pharma Corporation). Plasma (500 ul) was mixed with furosemide (internal standard, 500 ug/ml). Detection wavelength was 256 nm. The mixture of 0.01 M ammonium acetate and acetonitrile 80:20 (v/v) was used mobile phase. The HPLC separation was accomplished on ODC reverse HPLC column. The nicorandil was analyzed by a HPLC system, which consists of CAPCELL PAK C18 column (5 ${\mu}$m, 4.6 × 150 mm) and a chromatography data analysis S/W, using a isocratic mobile phase (mixture of 0.01 M ammonium acetate and acetonitrile 80:20 ) at 1.0 ml/min. Its sensitivity, selectivity, accuracy and precision must be adequate for the bioavailabilty study of nicorandil, and the linearity ($r^2$ ≥ 0.9994) of nicorandil was also proved in the range of 0.05 ug/ml . 3 ug/ml. The pharmacokinetic parameters of nicorandil (5 mg) tablets were measured as the follow. AUC: 0.19 ug/ml·hr, $C_{max}$: 0.14 ug/ml, $t_{max}$: 0.58 hr, Ke: 0.11 hr., $t_{1/2\beta}$: 6.76 hrs. This method is simple and sensitive HPLC method using UV detector for determination of nicorandil in human plasma.

• 한국광학회지
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• 제3권2호
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• pp.105-110
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• 1992

광자기 기록 박막의 자기 광학효과에 의한 미소 편광 회전각을 축정하기 위하여 편광 변조 방법을 이용하였다. 편광 변조 방법은 Faraday 회전자로 레이저광의 편광을 변조하고 phase sensitive detection방법을 써서 변조된 신호만을 선택적으로 검출하는 것이다. 본 실험에서는 진공증착법으로 제작된 TbFeCo박막과 RF 스퍼터링으로 제작된 iron garnet 다결정 박막의 자기 Kerr 회전 및 Faraday 회전 이력곡선을 이 방법으로 조사하였다. 그 결과 $0.25^{\circ}$정도의 미소한 회전각을 측정하였으며 특히 longitudinal Kerr 회전의 경우 $2.5\times10^{-3^\circ}$정도의 매우 작은 회전각도 측정할 수 있었다.

• 약학회지
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• 제46권6호
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• pp.392-397
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• 2002

A simple and sensitive high performance liquid chromatographic method to quantitate ursodeoxycholic acid in crude drug pharmaceuticals was investigated. Ursodeoxycholic acid react with 2-bromoacetyl-6-methoxynaphthalene (Br-AMN) in the presence of triethylamine to form highly fluorescent derivative. The derivatization procedure was performed at 7$0^{\circ}C$ and completed within 30 min. The optimal wavelength of the fluorescence detector are λ$_{ex}$=300 nm and λ$_{em}$ = 460 nm. The LOD of the ursodeoxycholic acid was 25 ng/mι based on the S/N =3, and the LOQ was 80 ng/mι based on S/N = 10. Crude drug pharmaceuticals pretreated by solid phase extraction (Sep-pak $C_{18}$ cartridge) which were shown very good separation and recovery values for the compound.d.

• 약학회지
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• 제31권5호
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• pp.315-321
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• 1987

A high performance liquid chromatographic method was developed for the determination of glycyrrhetinic acid contained in licorice powder. Glycyrrhetinic acid which is hydrolysate of glycyrrhizin extracted from licorice powder, was determined with good result by HPLC using 2-bromoacetyltriphenylene labeling reagent. The glycyrrhetinic acids were labeled with 2-bromoacetyltriphenylene in acetonitrile using 18-crown-6-ether and KOH as a catalyst. Derivatized glycyrrhetinic acids were separated from the extracted licorice powder on a reversed-phase column (chemopak $C_{18}$) using 100% acetonitrile as a mobile phase and monitored by an UV-detector at 268nm. Linearity of calibration curve was obtained between 5 ng and 20 ng, and the lower limit of detection was 2 ng. The recovery of glycyrrhetinic acid to licorice powder was about 99.3%. This method was sensitive, reliable and useful for, determination of glycyrrhetinic acid.

• 전기학회논문지
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• 제58권10호
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• pp.1954-1961
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• 2009

This paper describes the development of a three-phase line-interactive dynamic voltage restorer with hybrid detection method, which is composed of three H-bridge inverter modules and super-capacitors. The operational feasibility was verified through computer simulations with PSCAD/EMTDC software, and experimental works with a 3kVA prototype. The developed system can compensate the input voltage sag and interruption within 2ms. The maximum allowable duration of voltage interruption is about 4 seconds. The developed system can be effectively used to compensate the voltage interruption in the sensitive load, such as computer, communication devices, and automation devices, and medical equipment. The developed system has a simple structure to be easily implemented with commercially available components, and to be highly reliable in operation.

• 전기의세계
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• 제14권1호
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• pp.5-12
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• 1965

In the designs of the sensitive electronic devices such as phase sensitive detector, X-ray diffractometer, and neutron diffractometers, we must take into account the geometrical factors in a coil systems and extraneous stray fields. Input wave forms in such a sensitive electronic devices are often altered by the influence of these factors. Since the magnitude of the stray fields is generally very small, this affection may be removed by applying a good shielding but it is not ease to remove the affection from a geometrical factor. This affection must be however calculated by the theoretical methods and analytical solution in the equation of these factors. The fundamental purpose of this paper lie in the theoretical calculations and practical measurements of the geometrical factor in the coil systems, finite solenoid, and four point prove. In the heoretical calculations, the geometrical factors in the coil systems were calculated by applying the elliptic functions and in the contact points were calculated by applying the elliptic functions and in the contact points were calculated by applying the eigen functions and the infinite series. The measurements were carried out by using the sensitive electronic device made from author's design, as shown in the Fig. 9. The result of this work has verified the essential correctness of theoretical investigations and measuring techniques of geometrical factors on the design of sensitive electronic devices. It also has several advantages such that: (1) all the data obtained may give effective data to designer to work on the field of sensitive electronic devices or microelectronic devices, (2) it has evidently explained the characteristics of electrical investigations and physical definition, and has removed the conventional error of geometrical factors in the coil systems and contact points.

• 한국동물위생학회지
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• 제26권2호
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• pp.145-149
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• 2003

To explore the most sensitive and useful method for simultaneous determination of 8 carbamate pesticides in livestock productions, the mixture of 8 carbonates was determined by HPLC with scanning fluorescence detector. For mobile phase water, acetonitrile and methanol program gradient showed more applicable sensitivity than water and acetonitrile program gradient used ExW 339 nm and EmW 445 nm for fluorescence detector. On using carbamate columns, the retention time was within 4 to 20 minutes. And this made it possible to separate and detect simultaneously. therefore we could analyze it exactly and efficiently and reduce time. The preparation process of MSPD method showed that the high recovery rate was more than 88.5% in most of the carbamate pesticides. Therefore we could say that it was an efficient and fast method analyzing out of lots of samples.

• Nuclear Engineering and Technology
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• 제55권7호
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• pp.2419-2431
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• 2023

Experiments related to Boron Neutron Capture Therapy (BNCT) accomplished at the Institute of Nuclear Techniques (INT), Budapest University of Technology and Economics (TUB) are presented. Relevant investigations are required before designing BNCT for vivo applications. Samples of relevant boron compounds (H₃BO₃, BDTPA) usually employed in BNCT were investigated with neutron beam. Channel #5 in the research reactor (100 kW) of INT-TUB provides the neutron beam. Boron samples are mounted on a carrier for neutron irradiation. The particle attenuation of several carrier materials was investigated, and the one with the lowest attenuation was selected. The effects of boron compound type, mass, and compound phase state were also investigated. To detect the emitted charged particles, a traditional ZnS(Ag) detector was employed. The neutron beam's interaction with the detector-detecting layer is investigated. Graphite (as a moderator) was employed to change the neutron beam's characteristics. The fast neutron beam was also thermalized by placing a portable fast neutron source in a paraffin container and irradiating the H₃BO₃. The obtained results suggest that the direct measurement approach appears to be insufficiently sensitive for determining the radiation dose committed by the Alpha particles from the ¹⁰B (n,α) reaction. As a result, a new approach must be used.