• Fire Science and Engineering
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• v.28 no.4
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• pp.64-72
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• 2014

Flammable liquids residues in fire debris and pyrolysis products of flammable materials were analyzed by using Gas detecting tube, Gas Chromatograph/Mass Spectrometers (GC/MS), and Pyrolyzer. Comparison studies between chemical components detected in debris fired with and without Flammable liquids were performed. Though Flammable liquids were not present in debris, Gas detecting tube colors were also changed. Chemical components produced from conventional combustions were different from those produced from pyrolysis. Due to the difference of the reaction conditions between combustions and pyrolysis, different chemical products were produced. Petrochemical products of PVC wood-linoleum block could produce ignitable chemicals, such as toluene, ethylbenzene, undecane, and dodecane. So, for better fire investigation more consideration of those chemicals will be porformed.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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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.

• Journal of the Korean Ceramic Society
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• v.27 no.8
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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.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06e
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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.

• Korean Journal of Optics and Photonics
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• v.13 no.6
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• pp.559-563
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• 2002

We measure the 3-dimensional temporal behavior of the light emitted from the discharge cell of a plasma display panel (PDP) by using a scanned point detecting system. The light signal detected by a PM tube is sent to the oscilloscope, and the oscilloscope is connected to a PC with GPIB. From the resultant temporal behaviors, we could analyze the discharge characteristics of the panel with a Ne-Xe (4%) mixing gas at a 400 torr pressure. The top view of the panel shows that discharge moves from the inner edge of the cathode electrode to the outer cathode electrode, forming an arc shape. The side view of the panel shows that the light is detected up to 150 $\mu\textrm{m}$ up the barrier rib. After a trigger pulse is applied, peak intensity is detected at 730 ns and peak intensity position is located at the center of the ITO electrodes.

• Carbon letters
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• v.5 no.4
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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.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.33-39
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• 2014

Chemical accidents are the cause of the accident site during the initial responders to quickly and easily see materials and concentration method for the U.S. Environmental Protection Agency(EPA) is widely used in the initial response team direct reading detection equipment used. Ministry of the tubular gas detection equipment to detect direct reading detection equipment used in the event of an accident scene, and shell-and-tube gas detector for rapid detection and identification and precise analysis of causative pollutants before about strategically can identify the quantitative and qualitative useful equipment. However, those who initially respond to the scene of a direct reading detection equipment and a simple lack of understanding of how to use the numbers only because of the way you want to check the accuracy of detection results have been raising questions about the increase. The scene of the accident in order to obtain an accurate detection results used in this paper, the Ministry of Environment of gas detectors detect tubular Kitagawa and Draeger detector tube to check the reactivity of the material on-site detection of early response of those who were to raise the accuracy of the results.

• Journal of the Korean Ceramic Society
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• v.22 no.4
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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%)

• Journal of IKEEE
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• v.19 no.4
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• pp.535-540
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• 2015

A microstrip gas chamber (MSGC), applied to digital radiography system, was designed and constructed. The microstrip electrodes were fabricated with Chrome(Cr.). by photolithography process on Silicon(Si) wafer and glass substrate. The width of anode and cathode electrodes was $10{\mu}m$, and $290{\mu}m$, respectively. The distance of the electrodes was $100{\mu}m$, and the active area was $50{\times}50mm^2$. And the number of anode was 80. The microstrip electrodes were damaged when discharges occurred over the 600 V of anode voltage. As the result of experiments. It detected the typical output signals of the pulse width, 20 ns, under the condition that the detecting gas was Ar(90%) + $CH_4$(10%), X-ray tube voltage was 42 kV, and tube current was 1 mA.

• Proceedings of the KIEE Conference
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• 2002.07c
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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.