• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.383-389
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• 2010

The vapor concentration of hexane in a liquid spray jet in crossflow was qualitatively measured on the basis of the infrared (IR) extinction techniques. The objectives of the present study are to understand the whole evaporation process from droplet breakup to vapor and to confirm the usefulness of IR emission method in a lab-scale ramjet combustor. From the experimental results, we concluded that hexane vapor mole fraction increased with temperature rise and kept nearly constant during the variation of fuel to air momentum ratio.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.4
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• pp.25-31
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• 2010

The vapor concentration of hexane in a liquid spray jet in crossflow was qualitatively measured on the basis of the infrared (IR) extinction techniques. The objectives of the present study are to understand the whole evaporation process from droplet breakup to vapor and to confirm the usefulness of IR emission method in a lab-scale ramjet combustor. From the experimental results, we concluded that hexane vapor mole fraction increased with temperature rise and kept nearly constant during the variation of fuel to air momentum ratio.

• Journal of the Korean Society for Nondestructive Testing
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• v.30 no.5
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• pp.484-488
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• 2010

Infrared emissivity is one of the most important factors for the temperature measurement by infrared thermography. Although the infrared emissivity of an object can be measured from the ratio of blackbody and the object, at room temperature it is practically difficult to measure the value due to the background effects. Hence, quantitative reflectance of bare steel plate and the surface of coating was measured by FT-IR spectroscopy and emissivity was calculated from this. The emissivity of polished bare steel surface was from 0.06 to 0.10 and the value for the unpolished bare steel can not be achieved because optical characteristics changes of surface roughness induces erroneous results. Emissivity of transparent paint coated steel was from 0.50 to 0.84. Depends on the IR absorption regions, which is a characteristic value of the coating, emissivity changes. This study suggests surface condition of material, thickness, roughness et cetra are important factor for IR optical characteristics. Emissivity measurement by reflection method is useful technique to be applied for metal and it with coating applied on the surface. The range of experimental errors of temperature can be narrowed by the application of infrared thermography from the measured thermal emissivity.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.6
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• pp.102-107
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• 2007

A fast response $CO_2$ ($fCO_2$) analyzer for real-time measurement of carbon dioxide concentration during transient states of internal combustion engines has been developed. This analyzer uses non-dispersive infrared absorption (NDIR) technique for measuring $CO_2$ concentration and Kalman filter for removing noise components from output signals. The analyzer has good linearity, repeatability and drift with a response time of 11 ms; it is sufficiently fast to detect $CO_2$ concentration during transient states of internal combustion engines. The $fCO_2$ analyzer was used to measure transient $CO_2$ concentration of exhaust gas of the SI engine with a standard gas analyzer, and the signal of the $fCO_2$ analyzer was compared to that of the standard gas analyzer. The two concentrations were well matched during the steady state, and the $fCO_2$ analyzer could measure the variations of $CO_2$ concentration during the transient state.

• The Journal of Natural Sciences
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• v.9 no.1
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• pp.53-56
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• 1997

The structure of poly-$\beta$-hydroxybutyrate (PHB) in Chlorogloea fritschii was analyzed by FT-IR spectrometry under various conditions (phosphate starves or sufficient conditions). They exhibited characteristic absorption peaks for PHB, such as C=O stretching band at 1700-1800 $cm^-1$and C-H stretching bands at about 2900 $cm^-1$, however, the intensity of C-H stretching peaks, relative to the rest of the spectrum was increased under phosphate starved condition, which suggests that C. fritschii might produce another modified PHB polymer under phosphate starved condition.

• Analytical Science and Technology
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• v.5 no.3
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• pp.285-294
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• 1992

Structures of dimers of the acetonitrile and DMF diluted by carbon-tetrachloride and xenon matrices at 80K were studied with infrared absorption spectroscopy. Sample and matrix materials were codeposited onto a KBr cold trapping window. Infrared absorption spectra of pure samples and diluted samples were compared to explain the structures of dimers. The acetonitrile dimer showed the antiparallel shape and the DMF dimer showed the linear shape. After annealing, the infrared spectrum of the diluted sample showed the same shape with that of the pure sample.

• 전기의세계
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• v.41 no.10
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• pp.16-23
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• 1992

원적외선의 이용은 에너지절약을 목적으로한 효율이 높은 열전파형태로서 주로 응용되고 있다. 따라서 방사체의 적외선 방사특성과 피가열체의 적외선 흡수특성과의 관계가 먼저 명확하게 규명되어야 한다. 그러면, 그 흡수특성과 정합된 원적외선 방사세라믹스의 제작도 가능하게 되어갈 것이므로 원적외선의 작용효과가 각종 분야에서 이용되어 갈 것이다. 예를들면 의료분야에서 과거에는 인체의 일부를 가온할 필요가 있을 때에는 고주파전류, 마이크로파 또는 환부를 유동 파라핀속에 넣어 환부를 따뜻하게 하는 방법 등이 있지만 만약 어떤파장의 원적외선이 인체의 피부 깊숙이 투과가 가능하다면 마이크로파 방생장치 대신에 원적외선의 발생장치가 값이 저렴하고 기온부를 국소로 제한 할 수 있으므로 널리 사용되어질 것이다. 또 식품분야에서는 에너지절약의 관점에서 뿐만아니라 조리의 관점에서도 원적외선의 이용이 진전되어 갈 것으로 생각된다. 한편 원적외선센서의 진전은 놀랄만하여 앞으로 초전도세라믹스를 이용한 원적외선 검출의 죠셉슨센서는 더욱 진전되어 질것으로 생각된다. 어떻든 각종 원적외선방사 세라믹스의 개발과 원적외선 영역에서의 파장 특성에 대한 측정법이 확립되어짐에 따라서 원적외선 이용은 앞으로 각종방면에 진전되어질 것이다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.5
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• pp.9-15
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• 2000

The 3 ${\mu}{\textrm}{m}$-thick PVDF (polyvinylidene fluoride) thin film have been prepared using physical vapor deposition with electric field, and its FT-IR spectrum, dielectric property and electric conduction phenomenon have been investigated. Since the characteristic peaks are detected at 509.45 ［$cm^{-1}$ /］ and 1273.6 ［$cm^{-1}$ /］in the FT-IR spectrum, we are confirmed that the $\beta$ -phase is dominant in the PVDF thin film. In the results of dielectric properties, the PVDF thin film shows anomalous dispersion, i.e. gradual decrease of dielectric constant with increase of frequency, and also that the dielectric absorption point changes from 200 Hz to 7000 Hz with increasing temperature of thin film, which is consistent with the Debye's theory. The activation energy ( $\Delta$H) obtained from temperature dependence of dielectric loss is 21.64 ㎉/mole. We confirm that the electric conduction mechanism of PVDF thin film is dominated by ionic conduction by investigating the dependence of the leakage current of the thin film on the temperature and the electric field.

• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.151-155
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• 1994

Polyamic acid alkylamine (N, N-dimethylhexadecylamine)(PAAS)염을 합성하여 그 합성여부를 확인하였으며 PAAS염의 Langmuir막의 ${\pi}-A$ 등온선 및 표면 전위 특성 등을 조사 하였다. Langmuir-Blodgett법에 의하여 PAAS염의 LB막을 여러종류의 기관에 누적하였으며 누적여부를 자외선 흡수 스펙트럼 및 적외선 투과 스펙트럼을 이용하여 조사하였다. 그리고 PAAS LB막을 열처리에 의하여 이미드(imide)화시켜 폴리이미드 LB막을 제조하였으며 그 이미드화 여부를 자외선 및 적외선 스펙트럼을 이용하여 조사하였다.

• Korean Journal of Crystallography
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• v.7 no.2
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• pp.133-146
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• 1996

Morphology and infrared absorbing characteristics of Pt-black prepared by electroplating have been investigated with XRD, SEM, and IR spectrophotometer. The Pt later was coated on Au-coated alumina/glass substrates for 1-5 min at pH 1.0-1.5, where a solution of platinum chloride and lead acetate was used as the electrolyte. At the electrical current density of 20-50 mA/㎠, the Pt-black showed a dendritic growth which was characterized by a "tree" shape. Absorptivity of above 90% at IR radiation of 10 m was observed for the Pt absorbing layer with an area density of ≥1.3mg/㎠.