• Journal of Internet Computing and Services
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• v.23 no.3
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• pp.57-65
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• 2022

International attempts to smuggle narcotics and explosives using ship or aircraft cargoes are on the rise. With the recent increase in the number of detection cases of narcotics and explosives in Korea, it is important to detect dangerous material (narcotics and explosives) through container searches at ports and airports, which are the main routes. This paper proposes a technique to detect dangerous material in cargo containers using the sampled output signal of ion mobility spectroscopy (IMS). The proposed technique estimates parameters such as a threshold, a window length, and a noise level for ion detection of the target dangerous material by using known materials in the initialization stage. The estimated parameters are used to detect the ions of the dangerous target material inside the containers. The proposed technique can be applied when the peak value of the IMS signal and the ion mobility are varying due to container environments.

• Journal of the Korean Chemical Society
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• v.43 no.4
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• pp.430-437
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• 1999

The determination of total chlorine residuals in drinking water by flow injection analysis(FIA) with iodometric UV detection was investigated. The pH of the acid stream, the concentration of the iodide ion,the length of the mixing and reaction coils, the injection sample size, and flowrate were optimized as parameters for determining total chlorine residuals by FIA method. lodide was selectively oxidized to iodine by hypochlorite at pH 8.3 Ethylenediamine as masking agent for masking interference ions from the sample was given the best efficency. Calibration curve presented linear range of 0.03-3 mg/L for hypochlorite ion with a correlation coefficient of 0.999 or better. The detection limit was found to be 0.007 mg/L for hypochlorite ion. Under these analytical conditions, total chlorine residuals in several tap water sampled in the city of Jeonju were analyzed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.1
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• pp.47-54
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• 2019

An improved method of spectrum detection algorithm for mass spectrum analysis system is proposed. In the conventional spectrum detection algorithm that utilizes the results of the linear approximation and quadratic curve fitting on the ion signal block of each mass index, it is possible to reduce the detection error in the mass spectrum detection by further improving the condition of eliminating the invalid ion signals. Also, the proposed method can reduce the estimation error of the peak value of the mass spectrum by using the result of quadratic curve fitting for the effective ion signal block in which the peak position error is corrected. To evaluate the effectiveness of the proposed method, computer simulations were carried out step by step using the measured ion signal. Also, by comparing the rate of false detection for several inputs, the proposed method showed better detection performance than the conventional method.

• Journal of the KSME
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• v.57 no.10
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• pp.48-52
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• 2017

이 글에서는 공간적으로 형상 제어된 나노구조물의 자기조립화(self-assembly)를 이용하여 고용량의 이온흐름이 가능한 나노전기수력학 기술에 대한 소개와 더불어, 이를 활용한 이온 다이오드, 고효율 마이크로 믹서, 이온농도차 발전 응용 및 향후 생체 내 이온검출 센서, 인체 삽입형 디바이스, 뇌-기계 인터페이스 연구에 대한 전망을 소개하고자 한다.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.77-77
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• 1999

박막시료의 분석에는 RBS, XPS, SIMS, AES 등이 주로 이용되고 있으며, 특히 RBS는 비교체가 필요없고 정량성이 좋다는 장점 때문에 중요하다. 그러나 RBS는 원리적으로 경원소에 대한 감도가 낮아 기판원소보다 무거운 질량을 갖는 원소의 분석에만 이용되는 것이 보통이다. 이러한 단점을 보완하기 위해 본 연구에서는 수년전부터 RBS와 비슷한 원리를 갖고 같은 장비를 이용하여 수행이 가능한 경원소 분석법인 TOF-ERDA(Time of Flight Elastic Recoil detection)을 개발하여 실용화 하였다. 본 연구실에서 보유하고 있는 미국 NEC사의 5SDH 가속기는 최대 가속전압이 1.7MV로 Cl5+ 이온을 사용하는 경우 10 MeV가 최대 가속에너지가 된다. 이런 정도의 에너지 범위에서는 TOF spectrometer의 시간분해능이 아주 높을 필요가 없고 비교적 작은 가속기로도 분석이 가능하며, 수소의 검출효율이 우수하다는 점 등 많은 장점이 있다. 그러나 한편으로는 분석가능한 깊이가 수천 $\AA$ 정도로 제한되고 질량 분해능도 수십 MeV 내지 100MeV 이상의 고에너지 이온빔을 이용하는 경우에 비해 떨어진다는 단점이 있다. 또한 묵운 원소의 분석이 불가능하기 때문에 경원소의 분석에 국한하여 적용하고 무거운 원소에 대해서는 RBS를 병용하게 된다. 본 연구에서는 일본 이화학연구소의 선형가속기인 RILAC으로부터 얻은 40MeV Ar 이온 및 138 MeV Xe 이온을 이용하여 TOF-ERDA 시스템을 제작하였다. 그러기 위해서 고에너지 이온의 비행시간을 측정하는 목적으로 높은 시간 분해능을 갖는 시간 검출기를 설계, 제작하였다. 또한 표적함 밑에는 회전원판이 있어 시간검출기 및 에너지 검출기가 중앙의 시료홀더를 중심으로 회전이 가능하도록 되었다. 회전은 표적함 밖에서 원격조정 가능하다. 이렇게 함으로써 검출각을 임의로 바꾸면서 측정이 가능하도록 하였다. 제작된 분석시스템의 성능을 확인하기 위해 YBaCuO 초전도 박막을 측정하였으며 그 결과를 그림에 나타낸다. 저 에너지 ERDA에서는 나타나기 힘든 Ba, Y, Cu 등의 무거운 원소의 피크들이 분명히 나타남을 확인할 수 있다.

• Journal of Radiation Protection and Research
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• v.9 no.2
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• pp.55-60
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• 1984

The optimum etching condition of allyl diglycol carbonate (CR-39) for detecting the 60 MeV N-ions was determined as $70^{\circ}C$, 20% NaOH for 130min, by considering the variations of track density and diameter. Under these conditions, the maximum detectable track density was $1.7{\times}10^7tr/cm^2$. Track densities were linearly increased with increase of the total charge of the incident 60 MeV N-ions. By considering the scattring of N-ions as the Rutherford elastic scattering of point source, the measured relative probability was well consistent with the calculated value. The detection efficiency of CR-39 was in the range of 54-41% for 60 MeV N-ions of 12 nC-100 nC.

• Journal of the Korean Chemical Society
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• v.44 no.6
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• pp.556-562
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• 2000

The determination of chlorite ion by flow injection analysis(FIA) with iodometric UV detection were investigated. Under rather acidic condition, chlorite ion react with iodide ion to form iodine and itself is reduced to chloride ion. The chlorite ion was determined indirectly by measuring absorbance of yellow colored iodine at 370 nm. The lengths of the mixing coil and the reaction coil, the pH of the acid stream, the concentration of the iodide ion, the injection loop volume, temperature, and flowrate were optimized as parameters for selectively determining a sort of inorganic disinfection by-product, chlorite ion by using FIA-UV detection setup. Masking agents for removing oxidants or interferences from the prepared water were tested. Independent calibration curve presented linear range of 0.002-0.2 mg/L for chlorite ion with a correlation coefficient of 0.999 or better. The limit of detection(LOD) was 0.18 ${\mu}g/L$ for chlorite ion.

• Journal of the Korean Vacuum Society
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• v.17 no.4
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• pp.262-269
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• 2008

The residual gas analyzer (RGA) is employed for the process control of a vacuum system by measuring residual gases in it. This review paper introduces operating principles of the RGA and problems that can be encountered during use, together with their possible solutions.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1148-1153
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• 2006

Signal measuring system to analyze ion concentrations in biofilm was constructed with ion selective microeleclrode and electrometer. In order to evaluate the performance and applicability of signal measuring system, the following characteristics, such as slope of calibration curve, detection limit, variation of response according to the time, and potentiometric selectivity coefficient, were investigated. The slope of calibration curve showed high degree of association for primary ion concentration. The response of the system was log-linear in standard solution down to $10{\mu}M$ and signal measuring system was not sensitive for interfering ions. In comparison with commercial electrometer, the fabricated electrometer system had similar tendencies for the slope of calibration curve, detection limit, and response time. Therefore the signal measuring system could be used to investigate ion profiles in biofilm as a cost effective and reliable measuring system.

• Korean Educational Research Journal
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• v.37 no.1
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• pp.33-45
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• 2016

We propose a research for detection of the fluoride ion using borane compounds. Based on the Lewis acid-base reaction, we discussed the fundamental of sensing for fluoride ion. One of the important aspects in the chemistry of organoboranes is their behaviors as Lewis acids, which is a result of the vacant $2p_{\pi}$ orbital on the tricoordinate boron center. The electronic interaction between boron atoms and ${\pi}$-orbitals of donor molecules, constructed from the carbon 2p orbitals, is generally strong. Boron atoms can reach the desired octet configuration either through ${\pi}$-overlap with a suitable X or through formation of Lewis acid-Lewis base complexes.