• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.52.1-52.1
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• 2009

Cupric oxide (CuO) is a p-type semiconductor with band gap of ~1.7 eV and reported to be suitable for catalysis, lithium-copper oxide electrochemical cells, and gas sensors applications. The nanoparticles, plates and nanowires of CuO were found sensing to NO2, H2S and CO. In this work, we report about the comparison about hydrogen sensing of nano thin film and nanowires structured CuO deposited on single-walled carbon nanotubes (SWNTs). The thin film and nanowires are synthesized by deposition of Cu on different substrate followed by oxidation process. Nano thin films of CuO are deposited on thermally oxidized silicon substrate, whereas nanowires are synthesized by using a porous thin film of SWNTs as substrate. The hydrogen sensing properties of synthesized materials are investigated. The results showed that nanowires cupric oxide deposited on SWNTs showed higher sensitivity to hydrogen than those of nano thin film CuO did.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권2호
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• pp.140-145
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• 2008

In this paper, we constructed the advanced cargo monitoring system for liquid cargo tankers which embedded the Decision Support System (DSS) based on the International Ship Management Code (ISM Code). To make this system, we first organized a base of expert's knowledge concerning liquid tanker operations that largely affect ocean accidents. We can find out the knowledge via inference method which simply imitates the fuzzy inference method. Based on this expert's knowledge, we constructed the DSS that provides a code of conduct for operating cargo tanks safely. The proposed monitoring system could eliminate human error when confronting dangerous situations, so the system will help sailors to operate cargo tanks safely.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1445-1456
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• 2003

The ASTER TIR (thermal infrared radiometer) sensor has 5 spectral bands over 8 to 12 ${\mu}$m region. Rock type classification using the ASTER TIR nighttime data was performed in the Erta Ale range of the Ethiopian Rift Valley. Erta Ale range is the most important axial volcanic chain of the Afar region. The petrographic diversity of lava erupted in this area is very important, ranging from magnesian transitional basalt to rhyolites. We tried to classify the rock types based on the spectral behavior of each volcanic rock types in thermal infrared range and estimated SiO$_{2}$ content with emission data by the ASTER TIR.

• 한국항해항만학회지
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• 제43권5호
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• pp.281-288
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• 2019

In this paper, we implemented a mobile application of location-based augmented reality that combines self-sensing technology and various safety information using technological advancements of the smartphone. Vessel navigation is a suitable area for augmented reality because it requires accurate knowledge of the distance and location of destinations, danger zones, AtoN, and adjacent vessels. Current smartphone applications only provide 2D images and location information. Such applications do not include information about the surrounding environment, and as a result, they can only function using their own sensing information and surrounding information into a location-based augmented reality. If you provide a variety of sensor information embedded in the smartphone to 'BadaGO', the implemented application through this study, 'BadaGO' can provide safe navigation information to the user device in real time with a variety of its own formed information. The user has a high practicality and applicability of a small ship that is supplied with safe navigation information in a changing marine environment only by providing information through the application on the smartphone.

• Journal of Industrial and Engineering Chemistry
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• 제67권
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• pp.417-428
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• 2018

In this study, we fabricated hierarchically self-assembled thin films composed of graphene oxide (GO) sheets and gold nanoparticles (Au NPs) using the Langmuir-Blodgett (LB) and Langmuir-Schaefer (LS) techniques and investigated their gas-sensing performance. First, a thermally oxidized silicon wafer ($Si/SiO_2$) was hydrophobized by depositing the LB films of cadmium arachidate. Thin films of ligand-capped Au NPs and GO sheets of the appropriate size were then sequentially transferred onto the hydrophobic silicon wafer using the LB and the LS techniques, respectively. Several different films were prepared by varying the ligand type, film composition, and surface pressure of the spread monolayer at the air/water interface. Their structures were observed by scanning electron microscopy (SEM) and atomic force microscopy (AFM), and their gas-sensing performance for $NH_3$ and $CO_2$ was assessed. The thin films of dodecanethiol-capped Au NPs and medium-sized GO sheets had a better hierarchical structure with higher uniformity and exhibited better gas-sensing performance.

• Journal of Ginseng Research
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• 제46권3호
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• pp.331-336
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• 2022

Coronavirus disease 2019 (COVID-19) exhibits various symptoms, ranging from asymptomatic to severe pneumonia or death. The major features of patients in severe COVID-19 are the dysregulation of cytokine secretion, pneumonia, and acute lung injury. Consequently, it leads to acute respiratory distress syndrome, disseminated intravascular coagulation, multiple organ failure, and death. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of COVID-19, influences nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 (NLRP3), the sensor of inflammasomes, directly or indirectly, culminating in the assembly of NLRP3 inflammasome and activation of inflammatory caspases, which induce the inflammatory disruption in severe COVID-19. Accordingly, the target therapeutics for inflammasome has attracted attention as a treatment for COVID-19. Korean Red Ginseng (KRG) inhibits several inflammatory responses, including the NLRP3 inflammasome signaling. This review discusses the role of KRG in the treatment and prevention of COVID-19 based on its anti-NLRP3 inflammasome efficacy.

• 한국재료학회지
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• 제18권11호
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• pp.628-633
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• 2008

ZnO nanopowders were synthesized by the sol-gel method using hydrazine reduction, and their gas responses to 6 gases (200 ppm of $C_2H_5OH$, $CH_3COCH_3$, $H_2$, $C_3H_8$, 100 ppm of CO, and 5 ppm of $NO_2$) were measured at $300\;{\sim}\;400^{\circ}C$. The prepared ZnO nanopowders showed high gas responses to $C_2H_5OH$ and $CH_3COCH_3$ at $400^{\circ}C$. The sensing materials prepared at the compositions of [$ZnCl_2$]:[$N_2H_4$]:[NaOH] = 1:1:1 and 1:2:2 showed particularly high gas responses ($S\;=\;R_a/R_g,\;R_a$ : resistance in air, $R_g$ : resistance in gas) to 200 ppm of $C_2H_5OH$($S\;=\;102.8{\sim}160.7$) and 200 ppm of $CH_3COCH_3$($S\;= 72.6{\sim}166.2$), while they showed low gas responses to $H_2$, $C_3H_8$, CO, and $NO_2$. The reason for high sensitivity to these 2 gases was discussed in relation to the reaction mechanism, oxidation state, surface area, and particle morphology of the sensing materials.

• 한국수소및신에너지학회논문집
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• 제22권2호
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• pp.161-167
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• 2011

Proton conductors have attracted considerable attention for solid oxide fuel cell (SOFC), hydrogen pump, gas sensor, and membrane separators. Doped $SrCeO_3$ exhibits appreciable proton conductivity in hydrogen-containing atmosphere at high temperature. However commercial realization has been hampered due to the reactivity of $SrCeO_3$ with $CO_2$. The chemical stability and proton conductivity are dependent on dopant type. The purpose of this work is to investigate chemical stability of $SrCe_{0.95}Gd_{0.05}O_{3-\alpha}-Ce_{0.9}Gd_{0.1}O_{2-\beta}$ composites in $CO_2$ and $H_2$ gases. Thermogravimetric analysis (TGA) was performed in gaseous $CO_2$ and electrical conductivity of the composites were also measured between 500 and $900^{\circ}C$ in air and $H_2$ atmosphere. $SrCe_{0.95}Gd_{0.05}O_{3-\alpha}-Ce_{0.9}Gd_{0.1}O_{2-\beta}$ composite membranes showed good chemical stability of in $CO_2$ atmosphere and high conductivity at hydrogen condition. The hydrogen permeation of $SrCe_{0.95}Gd_{0.05}O_{3-\alpha}-Ce_{0.9}Gd_{0.1}O_{2-\beta}$ composite membranes was investigated as a function of volumetric content of $SrCe_{0.95}Gd_{0.05}O_{3-\alpha}$. The $SrCe_{0.95}Gd_{0.05}O_{3-\alpha}-Ce_{0.9}Gd_{0.1}O_{2-\beta}$(6:4) membrane with a thickness of 1.0 mm showed the highest hydrogen permeability with the flux reaching of 0.12 $ml/min{\cdot}cm^2$ at $800^{\circ}C$ in 100%$H_2/N_2$ as feed gas.

• 한국화재소방학회논문지
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• 제29권6호
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• pp.57-64
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• 2015

육상 및 해상에서 일어나는 화재를 진압하기 위한 가스계 소화설비 중 이산화탄소 소화설비는 우수한 성능 및 높은 경제성으로 인하여 널리 사용되고 있지만, 고농도 이산화탄소로 인한 질식사고가 빈번히 발생하여 안전문제가 항상 지적되어 왔다. 본 연구에서는 수치해석을 통하여 선박 내 압축기실의 이산화탄소 소화설비 화재 진압 특성을 예측하고, 이산화탄소 소화설비로 인한 질식사고를 방지하기 위한 2중 안전 제어기법을 제시하여, 이산화탄소 소화설비의 안전을 도모하였다. 수치해석 결과로는 4가지 시나리오를 선정하여, 화재발생 후 이산화탄소 소화설비 작동으로 인한 열발생률 변화, 온도변화, 이산화탄소 농도변화, 산소 농도변화 및 화재진압 특성을 고찰하였으며, 방호구역 내 환기팬 용량이 충분하지 않은 경우의 위험성 및 적절한 환기시스템의 필요성을 제시하였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.462-462
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• 2009

$CeO_2$는 고체 산화물 연료전지 (SOFC, soild oxide fuel cell)의 전해질 재료와 CMP(Chemical Mechanical Polishing) 슬러리 재료, 자동차의 3원 촉매, gas sensor, UV absorbent등 여러 분야에서 사용되고 있다. 본 연구에서는 위의 활용범위 외에 $CeO_2$의 구조적 안정성과 빠른 $Ce^{3+}/Ce^{4+}$의 전환 특성을 이용하여 lithium ion battery의 anode 재료로서 전기화학적 특성을 알아보고자 실험을 실시하였다. $CeO_2$ 합성에 사용되는 전구체인 cerium carbonate의 형상 및 크기, 비표면적과 같은 물리화학적 특성이 $CeO_2$ 분말의 특성에 직접적인 영향을 주기 때문에 전구체의 합성 단계에서 입자의 특성을 조절하였다. 전구체 합성의 출발원료로 cerium nitrate hexahydrate 와 ammonium carbonate를 사용하였고 반응온도 및 농도 등을 변화시켜 입자의 형상 및 결정상을 fiber형태의 orthorombic $Ce_2O(CO_3)_2{\cdot}H_2O$와 구형의 hexagonal $CeCO_3OH$의 세리아 전구체를 합성하였다. 이를 $300^{\circ}C$에서 30분 동안 하소하여 전구체의 입자형상을 유지하는 cubic $CeO_2$를 합성하고 X-ray diffraction, FE-SEM, micropore physisorption analyzer 분석을 통하여 입자의 결정상과 형상, 비표면적 등을 비교 분석하고 $Li/CeO_2$ couple의 충,방전 용량과 수명특성을 비교 분석하여 $CeO_2$의 전기화학적 특성을 알아보았다.