• Bulletin of the Korean Chemical Society
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• 제11권1호
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• pp.70-71
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• 1990

• Bulletin of the Korean Chemical Society
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• 제10권4호
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• pp.404-406
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• 1989

• Bulletin of the Korean Chemical Society
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• 제11권3호
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• pp.187-188
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• 1990

• 한국군사과학기술학회지
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• 제7권4호
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• pp.100-106
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• 2004

The effects of adiabatic flame temperature and mass flux on deuterium fluoride(DF) chemical laser performance were investigated. The power flux and specific power, which are important parameters containing the information of scaling effects of laser device magnitude, and chemical efficiency were selected as a judging parameter of DF laser performance. For the specific power, it was decreased by the increase of power flux of DF laser. Higher the adiabatic flame temperature of atomic fluorine generator, higher the chemical efficiency of DF laser was changed. It seems that the mass flux effect on the chemical efficiency is not remarkable.

• Bulletin of the Korean Chemical Society
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• 제32권5호
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• pp.1630-1634
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• 2011

Electroless plating of metallic nickel on carbon fiber surfaces was carried out to control specific electric resistivity of the fibers, and the effects of the nickel content and coating thickness on the electric properties were studied. The structural and surface properties of the carbon fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The specific resistivity of the fibers was measured using a four-point probe testing method. From the XPS results, the oxygen and Ni atomic ratio of the fibers was greatly enhanced as the plating time increased. Additionally, it was observed that the specific electric resistivity decreased considerably in the presence of metallic nickel particles and with the formation of nickel layers on carbon fibers.

• 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.

• Journal of Electrical Engineering and Technology
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• 제7권6호
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• pp.971-976
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• 2012

A 150 kJ compact capacitive pulsed power system (CCPPS) capable of delivering electrical energy into an electrothermal chemical (ETC) gun on a vehicle has been studied. The CCPPS provides pulsed electrical energy into a capillary plasma injector which generates plasma of tens of thousands $^{\circ}K$ in temperature and has a nonlinear resistance depending on the current. The design requirements of the CCPPS are as follows: the maximum power of 250 MW, the pulse width of about 0.6 ms, the volume of no more than 0.5 cubic meter, the efficiency of energy transfer over 80 % and the repetition rate of 4~5 times per minute. The constructed CCPPS is composed of four 37.5 kJ capacitor bank modules in parallel to make a trapezoid pulse shape and to satisfy the design requirements. Each module is designed to achieve high reliability, safety, efficiency and energy density to endure severe operating conditions. The results of the performance test on the CCPPS using a 120 mm ETC gun are described.

• Archives of Metallurgy and Materials
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• 제63권3호
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• pp.1509-1512
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• 2018

In this research, we investigated the effects of reduction atmospheres on the creation of the Mo-Si-B intermetallic compounds (IMC) during the heat treatments. For outstanding anti-oxidation and elevated mechanical strength at the ultrahigh temperature, we fabricated the uniformly dispersed IMC powders such as Mo₅SiB₂ (T2) and Mo₃Si (A15) phases using the two steps of chemical reactions. Especially, in the second procedure, we studied the influence of the atmospheres (e.g. vacuum, argon, and hydrogen) on the synthesis of IMCs during the reduction. Furthermore, the newly produced IMCs were observed by SEM, XRD, and EDS to identify the phase of the compounds. We also calculated an amount of IMCs in the reduced powders depending on the atmosphere using the Reitveld refinement method. Consequently, it is found that hydrogen atmosphere was suitable for fabrication of IMC without other IMC phases.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1280-1282
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• 1994

The method of passivation for protecting the $Hg_{l-x}Cd_xTe$ surface is important device fabrication process, because the surface components are highly reactive leading to its chemical and electrical instability. Especially, the material of which composition is x=0.2 or 0.3, is narrow bandgap semiconductor and used as detector of infrared radiation. The device performance of narrow bandgap semiconductors are largely governed by the properties of the semiconductor surface. The electro-chemical processing of $Hg_{l-x}Cd_xTe$ allows rigorous control of the surface chemistry and provides an in-situ monitor of surface reaction. So electro-chemical reduction at specific potential can selectively eliminate the undesirable species on the surface and manipulated to reproducibly attain the desired stoichiometry. This method shows to assess the quality or chemically treated $Hg_{l-x}Cd_xTe$ good surface.

• Carbon letters
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• 제9권2호
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• pp.105-107
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• 2008

In this work, we employed an electroless nickel plating on glass fibers in order to enhance the electric conductivity of fibers. And the effects of metal content and plating time on the conductivity of fibers were investigated. From the results, island-like metal clusters were found on the fiber surfaces in initial plating state, and perfect metallic layers were observed after 10 min of plating time. The thickness of metallic layers on fiber surfaces was proportion to plating time, and the electric conductivity showed similar trends. The nickel cluster sizes on fibers decreased with increasing plating time, indicating that surface energetics of the fibers could become more homogeneous and make well-packed metallic layers, resulting in the high conductivity of Ni/glass fibers.