• 한국화재소방학회논문지
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• 제28권4호
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• pp.64-72
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• 2014

본 연구에서는 연소잔류물에 남아있는 미세한 인화성액체의 성분을 검출하기 위해 가스검지관, Gas Chromatograph/Mass Spectrometer (GC/MS), 열분해분석장비를 활용하였다. 일반적으로 연소했을 경우와 인화성액체를 첨가하여 연소된 경우의 성분분석결과를 비교하였다. 결과적으로 인화성액체를 첨가하지 않고 연소 후 생성된 화재잔해물에서도 가스검지관이 반응하는 것을 확인할 수 있었다. 일반적인 연소와 열분해를 통해 생성된 화학성분의 차이가 있었으며, 이는 연소 환경의 차이로 인한 것으로 판단된다. 대표적인 석유화학제품인 우드데코타일(PVC) 시료는 인화성액체를 첨가하지 않고 일반적으로 연소시켰을 경우에도 감정인의 정확한 판단을 방해할 수 있는 방해물질인 Toluene, Ethylbenzene, Undecane, Dodecane 등이 검출되는 것을 확인하였다.

• Journal of Microbiology and Biotechnology
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• 제18권9호
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• pp.1550-1554
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• 2008

A hydrogen sulfide $(H_2S)$ detecting tube was developed for the quantitative determination of $H_2S$ produced by yeast during laboratory scale wine fermentations. The detecting tube consisted of a small transparent plastic tube packed with an $H_2S$-sensitive color-indicating medium. The packed medium changed color, with the color change progressing upward from the bottom of the tube, upon exposure to $H_2S$ produced by yeast during fermentation. A calibration study using a standard $H_2S$ gas showed that the length of the portion that darkened was directly related to the quantity of $H_2S$ (${\mu}g$) with a high correlation coefficient ($r^2$=0.9997). The reproducibility of the $H_2S$ detecting tubes was determined with five repetitive measurements using a standard $H_2S$ solution [5.6${\mu}g$/200 ml (28 ppb)], which resulted in a coefficient of variation of 3.6% at this level of $H_2S$. With the sulfide detecting tubes, the production of $H_2S$ was continuously monitored and quantified from laboratory scale wine fermentations with different yeast strains and with the addition of different levels of elemental sulfur to the grape juice. This sulfide detecting tube technology may allow winemakers to quantitatively measure $H_2S$ produced under different fermentation conditions, which will eventually lead winemakers to better understand the specific factors and conditions for the excessive production of $H_2S$ during wine fermentation in a large production scale.

• 한국세라믹학회지
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• 제27권8호
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• pp.1004-1010
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• 1990

SnO2-ThO2-PdCl2-In2O3 gas sensing ceramic systems were studied in order to lowr the operating temperatures and reduce the dependence of ambient temperatures and humidities. Sensing materials were coated by brush on the alumina tube followed by the impregnation of solidfier(ethylsilicate). Coated species were dried and sintered at 75$0^{\circ}C$ for 30min. carbon monoxide gas detecting sensitiviteis were measured in various ambinet temperatures and humidities. In the composition of 94SnO2-5ThO2-PdCl2 system carbon monoxide gas detecting sensors showed the highest detecting sensitivities and the lowest operating temperature(15$0^{\circ}C$). As the ambient temperatures and humidities were increased, sensitivities were decreased. Because the oscillation effects were observed at high humidities, it was suggested that the sensitivities of sensors depend greatly on the humidities.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1998년도 학술발표대회 논문집 제17권 2호
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• pp.247-250
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• 1998

The scattering of plane ultrasonic waves by the nuclear fuel pin of liquid metal reactor in sodium is studied. According to the internal composition in the cladding tube, the fuel pin has three cross sections, i.e. helium gas plenum, sodium-filled section, and fuel insertion section. The scattering spectra for each section of the fuel pin are different. The circumnavigating ultrasonic waves of each section are analyzed by the resonance scattering method. The whispering gallery wave modes are generated in the sodium-filled plenum section and the fuel rod insertion section with a sodium-gap. The circumferential wave modes are propagated in the cladding tube of the helium gas plenum section. The annular gap between the cladding tube and metal uranium pellet rod affects the scattering spectra. The different propagation characteristics can be utilized for the nondestructive method of detecting the unbonded area and measuring the level of the sodium-filled section of the fuel pin.

• 한국광학회지
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• 제13권6호
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• pp.559-563
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• 2002

본 논문에서는 직접 고안한 scanned point-detecting system(SPDS)을 이용하여 PDP 방전 셀 내에서 방출되는 광을 3차원 적으로 시간 분해하여 측정하였다. PM tube를 통해 검출된 광 신호를 오실로스코프 상에서 파형을 확인하고 PC제어를 통해 결과를 얻었다. Ne-Xe(4%) 혼합가스가 400 ton압력으로 채워진 패널에서 측정한 시간 분해 결과를 살펴보면 패널의 전면판(top view)에서는 방전이 cathode전극의 안쪽 edge에서 시작되면서 cathode전극 바깥쪽으로 호의 형태를 이루면서 진행되는 것을 알 수 있었으며 패널의 측면(side view)에서 측정한 시간 분해 결과를 살펴보면 약 150$\mu\textrm{m}$의 높이까지 방전에 의한 광이 검출되었다. 그리고 구동전압 펄스가 인가된 후 730 ns에서 가장 큰 intensity가 나타났다.

• Carbon letters
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• 제5권4호
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• pp.186-190
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• 2004

In this work, a nickel metal (Ni) electroplating on the activated carbon fiber (Ni/ACFs) surfaces was carried out to remove the toxic hydrogen chloride (HCl) gas. The surface properties of the treated ACFs were determined by using nitrogen adsorption isotherms at 77 K, SEM, and X-ray diffraction (XRD) measurements. HCl removal efficiency was confirmed by a gas-detecting tube technique. As a result, the nickel metal contents on the ACF surfaces were increased with increasing the plating time. And, it was found that the specific surface area or the micropore volume of the ACFs studied was slightly decreased as increasing the plating time. Whereas, it was revealed that the HCl removal efficiency containing nickel metal showed higher efficiency values than that of untreated ACFs. These results indicated that the presence of nickel metal on the ACF surfaces played an important role in improving the HCl removal over the Ni/ACFs, due to the catalytic reactions between nickel and chlorine.

• 한국재난정보학회 논문집
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• 제10권1호
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• pp.33-39
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• 2014

화학사고 발생 시 현장 초기대응자들은 사고 원인물질과 농도를 신속하고 손쉽게 확인하기 위한 방식으로, 미국 환경청(EPA) 초기대응팀에서도 널리 사용하고 있는 직독식 탐지장비를 이용하고 있다. 환경부에서는 검지관식 가스 탐지장비를 직독식 탐지장비로 이용하여 사고 발생 시 현장에서 이용하고 있고, 검지관식 가스탐지기는 신속한 원인 물질 확인과 정밀한 분석 전에 전략적으로 대략적인 오염물질의 정량과 정성을 확인할 수 있는 유용한 장비이다. 그러나 현장 초기대응자들의 직독식 탐지장비의 사용방법에 대한 이해 부족과 단순 수치로만 확인하려는 방식으로 인해 탐지결과의 정확성에 대한 의문점을 늘 제기해 왔다. 본 논문에서는 사고 현장에서 정확한 탐지 결과를 얻기 위해 환경부에서 사용하고 있는 검지관식 가스탐지기인 Kitagawa와 Draeger 탐지기의 물질 반응성을 확인하여 초기 대응자들의 현장 탐지결과의 정확성을 높이고자 하였다.

• 한국세라믹학회지
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• 제22권4호
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• pp.54-60
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• 1985

Gas sensing materials for detecting flammable gases such as $CH_4$, $C_3H_8$ and n-$C_4H_{10}$ were developed by util-izing $In_2O_3$ as the principal sensing material. The sensing materials were formulated by mixing $In_2O_3$ powder with one or two other chemicals such as $SnO_2$, $Y_2O_3$ and $Al_2O_3$ with a small addition of $PdCl_2$ as a catalyst. Sample of sensor were fabricated by coating each of the mixtures on a ceramic tube impregnating ethylsili-cate and firing at 75$0^{\circ}C$ Each material mixture was evaluated by measuring and comparing gas sensitivity(resistance in air/resistance with gas) to flammable gases such as $CH_4$, $C_3H-8$ and n-$C_4H_{10}$. It was found that among fifteen compositions tested three compositions as follows show the highest gas sensitivity and thus are very feasible for commercialization as the gas sensors ; o49.5 $In_2O_3$+50 Al2O3_0.5 PdCl2(wt%) o $20In_2O_3+29$ $SnO_2+50$ $Al_2O_3+1$ $PdCl_2$(wt%) o40 $In_2O_3$+9 $Y_2O_3+50$ $Al_2O_3+1$ $PdCl_2$(wt%)

• 전기전자학회논문지
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• 제19권4호
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• pp.535-540
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• 2015

디지털 X-선 촬영 장치에 응용되는 MSGC형 검출기를 설계 및 제작하였다. 기판의 재질은 실리콘기판과 유리기판을 사용하였으며, 기판위에 증착된 전극물질은 포토리소그래피 공정을 이용하였으며, 크롬을 전극의 재료를 이용하였다. 양전극의 폭은 $10{\mu}m$, 음전극의 폭은 $290{\mu}m$로 각각 제작하였다. 양전극과 음전극 사이의 거리는 $100{\mu}m$ 이고, 검출기의 유효영역은 $50{\times}50mm^2$로 설계하였다. 그리고 양전극의 수는 80개로 하였고, 양전극의 전압이 600 Volt 이상 인가한 경우 양전극과 음전극 부분이 방전되어 끊어진 현상을 확인하였다. 결과적으로 검출기체인 Ar(90%) + $CH_4$(10%) 기체 하에서 X-선관의 전압은 42 kV, 최대전류 1 mA까지 인가하여 연구를 수행하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1628-1630
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• 2002

In this paper, we measured 3-dimensional temporal behavior of the light emitted from discharge cell of plasma display panel(PDP) as a function of the pressure using the scanned point detecting system. The detected light signal through the PM tube is sent on the oscilloscope and oscilloscope which is connected to PC with GPIB. The whole system is controlled by a PC. From the temporal behavior results, we could analyze the discharge behavior of panel with Ne-Xe(4%) mixing gas and 300torr, 400torr, 500torr pressure. The top view of panel shows that the discharge moves from inner edge of cathode electrode to outer cathode electrode forming arc type. At the 300torr, initial emission time is very fast. The side view of panel shows that the light is detected up to $150{\mu}m$ height of barrier rib. In the panel of 300torr, emission distribution is wider than the others.