• Fire Science and Engineering
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• v.26 no.6
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• pp.7-14
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• 2012

This paper is to develop analytical techniques of flammable liquids which have been used for accelerating fire in accidental fires and arsons. We tested the temperature distribution of ceiling, fire patterns on the floor, and existence of flammable liquids and a check with GC/MS about flammable liquids comparing with papers, newspapers, and clothing. Research findings are as follows. The temperature of ceiling is influenced by flame. So gasoline and thinner was observed that combustible materials would be burned by flame. The fire patten on the floor was observed that flammable liquids had specialized pattern comparing combustible materials. When combustible materials on the PVC (Polyvinyl chloride) floor was burned, they didn't react to the gas detector. But flammable liquids had opposite results. After 7 days, we identified components of fire residues with the GC/MS (Gas Chromatography/Mass Spectrometry) about existence of flammable liquids and got components of flammable liquids. Fire investigation is a complicated processes. But we understand characteristics of materials, need detail investigations, and use the GC/MS to analyse flammable materials.

• Journal of the Korean Society for Nondestructive Testing
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• v.17 no.3
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• pp.151-155
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• 1997

In this research, nondestructive test using a radioisotope, $^{241}Am$ gamma-ray, was accomplished in order to evaluate the fiber volume fraction of the accumulated composite layers such as glass fiber/epoxy and carbon fiber/epoxy. Attenuation coefficients of the fiber and resin were measured respectively by NaI(T1) detector The fibers volume fraction was measured for various thickness of composite layers between 2 and 20mm. Fiber volume fraction of the composite layers were also measured for various amount of fibers. The experimental errors from nondestructive test using gamma-ray were in the range of ${\pm}1{\sim}2.5%$ in comparison with those from observation by optical microscopy. By selecting the optimum energy and activity of radioisotope, this method can provide a new means for the evaluation of the fiber volume fraction.

• Transactions on Electrical and Electronic Materials
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• v.18 no.5
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• pp.261-264
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• 2017

$Ni_{0.79}Co_{0.15-x}Cu_xMn_{2.06}O_4$ ($0{\leq}x{\leq}0.09$) thick films were fabricated using the conventional solid-state reaction method and screen-printing method. Structural and electrical properties of specimens based on the amount of Cu were observed in order to investigate their applicability in the infrared detector. All specimens showed a single spinel phase with a homogeneous cubic structure. As the amount of Cu increased, the average grain size increased and was found to be approximately $5.01{\mu}m$ for the $Ni_{0.79}Co_{0.06}Cu_{0.09}Mn_{2.06}O_4$ specimen. The thickness of all specimens was approximately $55{\sim}56{\mu}m$. As Cu content increased, the resistivity and TCR properties at room temperature decreased, and these values for the $Ni_{0.79}Co_{0.06}Cu_{0.09}Mn_{2.06}O_4$ specimen were $502{\Omega}-cm$ and $-3.32%/^{\circ}C$, respectively. The responsivity and noise properties decreased with an increase in Cu content, with the specimen with a Cu content of x=0.09 showing 0.0183 V/W and $5.21{\times}10^{-5}V$, respectively.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.05a
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• pp.22.1-22.1
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• 2007

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.257-257
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• 2005

• Proceedings of the Korean Magnestics Society Conference
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• 2007.12a
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• pp.94-95
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• 2007

• Proceedings of the Materials Research Society of Korea Conference
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• 2004.05a
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• pp.87-87
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• 2004

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.84-84
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• 2005

• Electrical & Electronic Materials
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• v.21 no.2
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• pp.39-47
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• 2008

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.131-131
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• 2003

Surface micromachined uncooled IR detector with the optimized VOx bolometric layer was fabricated based on sandwich structure of the V$_2$O$_{5}$V/V$_2$O$_{5}$. In order to improve the detectivity of the IR detector, we optimized a few factors in the viewpoint of bolometric material. Vanadium oxide thin film is a promising material for uncooled microbolometers due to its high temperature coefficient of resistance at room temperature. It is, however, very difficult to deposit vanadium oxide thin films having high temperature coefficient of resistance and low resistance because of process limits in microbolometer fabrication. In order to increase the responsivity and decrease noise, we increase TCR of bolometric material and decrease room temperature resistance based on the sandwich structure of the V$_2$O$_{5}$V/V$_2$O$_{5}$ by conventional sputter. By oxygen diffusion through low temperature annealing of V$_2$O$_{5}$V/V$_2$O$_{5}$ in oxygen ambient, various mixed phase vanadium oxide was formed and we obtained TCR in range of-1.2 ~-2.6%/$^{\circ}C$ at room temperature resistance of 5~100k$\Omega$.mega$.