• Korean Chemical Engineering Research
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• 제49권3호
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• pp.348-351
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• 2011

본 연구에서는 폴리다이아세틸렌(polydiacetylene, PDA) 베시클을 이용하여 여러 가지 킬레이트제(chelating agent)를 쉽게 검출할 수 있는 센서 시스템을 개발하였다. 다른 센서들과 비교하여 PDA기반 센서는 많은 장점이 있다. 첫째로, 형광물질의 부착이 필요 없는 무표지 검출(label-free detection)이 가능하여 실험 절차가 간단하고 빠르다. 둘째로, PDA는 청색에서 외부 자극에 의해 적색으로 변화하는 색전이를 일으키므로 육안으로 쉽게 검출을 확인할 수 있었다. 끝으로, 특정 파장에서의 colorimetric response를 측정하여 각각의 킬레이트제의 농도에 따른 정량검출도 가능하다. 본 연구에서는 5가지 종류의 킬레이트제, 즉 EDTA, EGTA, NTA, DCTA, DTPA를 PDA 베시클과 반응시켰으며, 이중에서 EDTA, DCTA는 특히 강한 반응으로 PDA의 색전이를 유도함을 알 수 있었다. 본 연구를 통하여 PDA 베시클을 사용하여 어떠한 기계나 동력을 사용하지 않고 색전이를 이용하여 킬레이트를 성공적으로 검출할 수 있음을 보여주었다.

• 한국유체기계학회 논문집
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• 제17권6호
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• pp.69-73
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• 2014

To predict flow fields and chemical agent dispersion in urban area, wind tunnel experiments was performed. The agent was adopted MS (methyl salicylate) because the real chemical agent is unsafe. The exact concentration of methyl salicylate was generated by the commercial gas generator (STI-2500) and three different obstacle shapes were applied (i.e., rectangular, cylinder and pyramid). The concentration was measured with the qualified ion mobility sensor and gas chromatography. The data necessary for virtual test method of the real chemical agent were obtained.

• 한국군사과학기술학회지
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• 제17권1호
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• pp.8-14
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• 2014

Brightness temperature spectra acquired from FTIR(Fourier Transform Infrared)-SCADS (Standoff Chemical Agent Detection System) could be available for detection and identification of the chemical agents and pollutants from different background. IR spectrum range of 770 to 1350 $cm^{-1}$ is corresponding to "atmospheric window". A 2-dimensional(2D) brightness temperature spectrum was drawn from combining each data point through automatic continuous scanning of FTIR along with altitude and azimuth. At higher altitude, temperature of background was decreased but scattering effect of atmospheric gases was increased. Increase in temperature difference between background and blackbody in SCADS at higher temperature causes to increases in peak intensity of $SF_6$. This approach shows us a possibility that 2D visual information is acquired from scanning data with a single FTIR-SCADS.

• 센서학회지
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• 제28권3호
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• pp.139-145
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• 2019

Precautionary detection of chemical warfare agents (CWAs) has been an important global issue mainly owing to their toxicity. To achieve proper detection, many studies have been conducted to develop sensitive gas sensors for CWAs. In particular, metal-oxide semi-conductors (MOS) have been investigated as promising sensing materials owing to their abundance in nature and excellent sensitivity. In this review, we mainly focus on various MOS-based gas sensors that have been fabricated for the detection of two specific CWA simulants, 2-chloroethyl ethyl sulfide (2-CEES) and dimethyl methyl phosphonate (DMMP), which are simulants of sulfur mustard and sarin, respectively. In the case of 2-CEES, we mainly discuss $CdSnO_3-$ and ZnO-based sensors and their reaction mechanisms. In addition, a method to improve the selectivity of ZnO-based sensors is mentioned. Various sensors and their sensing mechanisms have been introduced for the detection of DMMP. As the reaction with DMMP may directly affect the sensing properties of MOS, this paper includes previous studies on its poisoning effect. Finally, promising sensing materials for both gases are proposed.

• Current Optics and Photonics
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• 제3권3호
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• pp.243-247
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• 2019

We have developed a compact, wavelength-selectable, Q-switched Nd:YAG laser at mid ultraviolet for chemical warfare agent detection. The fundamental wave at 1064 nm is delivered by a pulsed solid state laser incorporating with a square-type Nd:YAG rod in a resonator closed by two crossed Porro prisms for environmental reliability. The output energy at 213 nm ($5{\omega}$) and 266 nm ($4{\omega}$) by ${\chi}^{(2)}$ process in the sequentially disposed BBO crystals are measured to be 6.8 mJ and 15.1 mJ, respectively. The output wavelength is selected for $5{\omega}$ and $4{\omega}$ by a motorized wavelength switch. The energy ratio of the $5{\omega}$ to the $4{\omega}$ is varied from 0.05 to 0.85 by controlling the phase matching temperature of the nonlinear crystal for sum-frequency generation without change of the output pulse parameters.

• 한국군사과학기술학회지
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• 제25권2호
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• pp.210-217
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• 2022

Chemical warfare agents(CWA) such as nerve agents and vesicating agents show lethality by skin contamination. Skin protection, therefore, is one of the top priorities to deal with the growing threat from CWA. In an attempt to develop the most effective topical skin protectant(TSP), candidate substances including PFPE(perfluorinated polyether), PTFE(polytetrafluoroethylene), glycerin, and polysaccharides were evaluated in forms of various formulations against nerve agent simulant DMMP(dimethylmethyl phosphonate) penetration. The protective efficacy of the formulation against DMMP penetration was estimated as the onset time of color change of the KM9 chemical agent detection paper. Based on this study, it was found that several PFPE- and glycerin-based formulations exhibit remarkably superior efficacy as a protective cream. This protective cream is expected to be used as TSP for military application after further research.

• 한국군사과학기술학회지
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• 제17권1호
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• pp.122-128
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• 2014

Remote fourier transform infrared(FTIR) chemical imaging detection system allows detection and identification of gases in the atmosphere from long distances. In this paper, the appropriate field of view(FOV) of the FTIR imaging system was examined and the main performance of the system for the interferometer was described. For the determination of the FOV, simulations of gas dispersion range were performed with the NBC reporting and modeling software(NBC-RAMS) developed by ADD. As a result, minimum 192 mrad of FOV was required for the remote FTIR imaging system to visualize chemical warfare agents dispersed in several hundred meters. At the same time, 0.75 mrad of instantaneous field of view(IFOV) for a linear interferometer proper to take a FOV for the chemical agent imaging.

• 대한화학회지
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• 제67권6호
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• pp.415-419
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• 2023

In this study, we report the one-pot synthesis of reduced graphene oxide (rGO) containing platinum nanoparticles with catalytic activity to break down hydrogen peroxide as a peroxidase-mimicking catalyst. A single reducing agent was used to reduce graphene oxide and a platinum precursor at a moderately low temperature of 70℃. The rGO was homogeneously decorated with platinum nanoparticles. The catalytic activity of Pt-rGO was investigated for the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB), a peroxidase substrate, in the presence of hydrogen peroxide. The Pt-rGO coupled with glucose oxidase was also able to detect glucose at millimolar concentrations (up to 1 mM). Our results show that the Pt-rGO composite is a promising catalyst for the detection of hydrogen peroxide. This method was also applied for the detection of glucose.

• Current Applied Physics
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• 제18권11호
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• pp.1255-1260
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• 2018

In this work, a green and simple one-pot route was developed for the synthesis of highly fluorescent aminofunctionalized graphene quantum dots (a-GQDs) via hydrothermal process without any further modification or surface passivation. We synthesized the a-GQDs using glucose as the carbon source and ammonium as a functionalizing agent without the use of a strong acid, oxidant, or other toxic chemical reagent. The as-obtained aGQDs have a uniform size of 3-4 nm, high contents of amino groups, and show a bright green emission with high quantum yield of 32.8%. Furthermore, the a-GQDs show effective fluorescence quenching for $Cu^{2+}$ ions which can serve as effective fluorescent probe for the detection of $Cu^{2+}$. The fluorescent probe using the obtained aGQDs exhibits high sensitivity and selectivity toward $Cu^{2+}$ with the limit of detection as low as 5.6 nM. The mechanism of the $Cu^{2+}$ induced fluorescence quenching of a-GQDs can be attributed to the electron transfer by the formation of metal complex between $Cu^{2+}$ and the amino groups on the surface of a-GQDs. These results suggest great potential for the simple and green synthesis of functionalized GQDs and a practical sensing platform for $Cu^{2+}$ detection in environmental and biological applications.

• 한국군사과학기술학회지
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• 제18권5호
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• pp.612-620
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• 2015

Short-range detection of chemical agents deposited on ground surface using a standoff Raman system employing a pulsed laser at 248 nm is described. Mounted in a vehicle such as an NBC reconnaissance vehicle, the system is protected against toxic chemicals. As most chemicals including chemical warfare agents have unique Raman spectra, the spectra can be used for detecting toxic chemicals contaminated on the ground. This article describes the design of the Raman spectroscopic system and its performance on several chemicals contaminated on asphalt, concrete, sand, etc.