• Title/Summary/Keyword: FT-IR Spectrometer

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A Theoretical Study for the Design of Solar Air Heaters Using Porous Material (다공성 물질을 이용한 공기용 태양열 집열기의 설계를 위한 이론적 연구)

  • Hwang, Yong-Ha;Park, Seung-Ho;Kim, Jong-Eok
    • Solar Energy
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    • v.13 no.2_3
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    • pp.79-90
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    • 1993
  • A theoretical study is conducted for the design of solar air heaters using porous material. Radiative characteristics of glazing and porous absorbing media are found through spectral transmittances measured by the Visible spectrometer and the FT-IR. Using those characteristics the efficiencies of collectors are calculated one-dimensionally with the use of the Two-Flux radiation model. The efficiencies increase, as the air flow rates or albedos in the visible range increase, and as albedos in the IR range decrease. The optimum thickness of the porous medium of 15-mesh stainless steel wire screens is 0.001m, which represents the opacity of one.

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Direct Bonding Characteristics of 2 inch 3C-SiC Wafers for MEMS in Hash Environments (극한환경 MEMS용 2 inch 3C-SiC 기판의 직접접합 특성)

  • Chung, Yun-Sik;Ryu, Ji-Goo;Kim, Kyu-Hyun;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.11a
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    • pp.387-390
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    • 2002
  • SiC direct bonding technology is very attractive for both SiCOI(SiC-on-insulator) electric devices and SiC-MEMS(micro electro mechanical system) fields because of its application possibility in harsh environments. This paper presents pre-bonding techniques with variation of HF pre-treatment conditions for 2 inch SiC wafer direct bonding using PECVD(plasma enhanced chemical vapor deposition) oxide. The PECVD oxide was characterized by XPS(X-ray photoelectron spectrometer) and AFM(atomic force microscopy). The characteristics of the bonded sample were measured under different bonding conditions of HF concentration and an applied pressure. The bonding strength was evaluated by the tensile strength method. The bonded interface was analyzed by using IR camera and SEM(scanning electron microscope). Components existed in the interlayer were analyzed by using FT-IR(fourier transform infrared spectroscopy). The bonding strength was varied with HF pre-treatment conditions before the pre-bonding in the range of $5.3 kgf/cm^2$ to $15.5 kgf/cm^2$

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Isolation and Purification of Antimicrobial Active Substances from Aloe vera peel(II) (Aloe vera peel에서 항균활성 물질의 분리.정제(II))

  • 박정순;신용서;류일환;이갑상
    • The Korean Journal of Food And Nutrition
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    • v.13 no.2
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    • pp.146-151
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    • 2000
  • To evaluate anticaries and antiinflammation of Aloe vera peel, antimicrobial substances were extracted from Aloe vera peel and identified. The antimicrobial active substances of water extract were successfully purified with solvent fractionation, silica gel column chromatography, preparative thin layer chromatography and UV spectrophotometer. Two purified active substances were identified as aloe-emodin and barbaloin by Mass Spectrometer, 1H-NMR and FT-IR.

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Measurements of Transmittances and Calculations of Fundamental Radiative Properties (투과율의 측정 및 이를 이용한 복사물성치의 계산)

  • Hwang, Yong-Ha;Park, Seung-Ho;Lee, Young-Soo
    • Solar Energy
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    • v.14 no.2
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    • pp.29-37
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    • 1994
  • Radiative charaacteristics of glass windows and porous absorbing media which can be used for a solar air heater are determined through the measurements of spectral transmittances. Those in the visible range are measured by the UV-IR spectrometer. Refractive index of glass are obtained by the comparison of the measured transmittances and the correlations derived from the electromagnetic theory and are compared to the theoretical ones calculated from the classical dispersion theory. Absorption and back-scattering coefficients of 15-mesh stainless wire screens are calcuated by the comparison of the measured transmittances and the correlations derived from the two flux model.

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Use of FT-IR to Identify Enhanced Biomass Production and Biochemical Pool Shifts in the Marine Microalgae, Chlorella ovalis, Cultured in Media Composed of Different Ratios of Deep Seawater and Fermented Animal Wastewater

  • Kim, Mi-Kyung;Jeune, Kyung-Hee
    • Journal of Microbiology and Biotechnology
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    • v.19 no.10
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    • pp.1206-1212
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    • 2009
  • Growth rates, photosystem II photosynthesis, and the levels of chlorophyll $\alpha$ and secondary metabolites of Chlorella ovalis were estimated to determine if they were enhanced by the addition of swine urine (BM) or cow compost water (EP) that had been fermented by soil bacteria to deep seawater (DSW) in an attempt to develop media that enabled batch mass culture at lower costs. Growth of C. ovalis in f/2, f/2-EDTA+BM60%, DSW+BM30%, and DSW+EP60% was enhanced and maintained in the log phase of growth for 16 days. The cell densities of C. ovalis in DSW+EP60% ($4.1{\times}10^6$ Cells/ml) were higher than those of f/2 ($2.9{\times}10^6$ Cells/ml), f/2-E+BM60% ($3.7{\times}10^6$ Cells/ml), and DSW+BM30% ($2.7{\times}10^6$ Cells/ml). The growth rate was also more favorable for C. ovalis cultured in DSW+EP60% ($0.15\;day^{-1}$) than that of C. ovalis cultured in the control medium (f/2) ($0.12\;day^{-1}$). Furthermore, the chlorophyll a concentration of C. ovalis cultured in DSW+EP60% (4.56 mg/l) was more than 2-fold greater than that of C. ovalis cultured in f/2 (2.35 mg/l). Moreover, the maximal quantum yields of photo system II at 470 nm (Fv/Fm) were significantly higher in organisms cultured at f/2-E+BM60% (0.53) and DSW+EP60% (0.52) than in the other treatment groups. Finally, Fourier transformation infrared (FT-IR) spectroscopy revealed that C. ovalis grown in DSW+EP60% had more typical peaks and various biochemical pool shifts than those grown in other types of media. Taken together, the results of this study indicate that the use of DSW+EP60% to culture C. ovalis can reduce maintenance expenses and promote higher yields.

Organic Residues Analysis of Oil Bottle of Goryeo Dynasty Excavated from the Soejeoul Site, Geumneung-dong, Chungju (충주 금릉동 쇠저울유적 출토 고려시대 유병의 유기물 분석)

  • Yun, Eun Young;Kim, Suyeon
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.638-647
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    • 2021
  • Organic residues are substances derived from diverse natural sources. Recent scientific analysis of organic residues has yielded important information in restoring the lifestyles of ancient peoples. In this study, the organic material contained within the celadon oil bottle of the Goryeo dynasty, excavated from the Soejoul site in Geumneung-dong, Chungju, was analyzed using Fourier-transform infrared spectroscopy (FT-IR) and gas chromatograph-mass spectrometer (GC-MS). The results showed that the organic materials in the bottle were plant-derived oils. In particular, polyunsaturated fatty acids and phytosterols were detected using GC-MS analysis. Sesamin components were also identified. Sesamin, which is a characteristic component of sesame seeds, is a lignan and an antioxidant. As the organic residues in the oil bottle were derived from sesame seeds, it is presumed that sesame oil was stored in the bottle.

The Study for Synthesis and Characteristic of ${\alpha},{\beta}$-tetra(phenoxy, 2-naphthoxy, 4-tritylphenoxy) Oxovanadium Phthalocyanine Derivatives (${\alpha},{\beta}$-tetra(phenoxy, 2-naphthoxy, 4-tritylphenoxy) Oxovanadium 프탈로시아닌 유도체의 합성 및 특성에 관한 연구)

  • Son, Dae-Hee;Heo, Jin;Kim, Song-Hyuk;Lee, Seung-Ho;Lee, Gun-Dae;Hong, Seong-Soo;Park, Seong-Soo
    • Applied Chemistry for Engineering
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    • v.21 no.6
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    • pp.638-642
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    • 2010
  • After phthalonitrile derivatives were synthesized by the introduction of phenoxy, 2-naphthoxy or 4-trityl phenoxy group on ${\alpha}$- and ${\beta}$-position, oxovanadyl phthalocyanine (VOPc) derivatives containing electron-rich substituent group at different position were synthesized successfully in this investigation. The chemical structure of samples was determined by the means of $^1H$-NMR, MALDI-TOF mass spectroscopy, and FT-IR spectrometer. Also, optical and chemical properties were determined by the means of UV-Vis spectrometer, X-ray diffractometry, and thermo gravimetry. It was found that the maximum absorbing wavelength of VOPc derivatives ranged from 684 to 726 nm. Also, their solubility and Q-band were enhanced and shifted by the introduction of substitute group, respectively.

Surface Modification of Flake-Shaped Inorganic Mica and Their Cool Paint Performances (판상형 무기소재인 Mica의 표면개질 및 차열페인트의 특성 평가)

  • Park, Jeong Min;Kim, Hee Jung;Yoo, Jung Whan
    • Applied Chemistry for Engineering
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    • v.27 no.1
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    • pp.35-38
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    • 2016
  • In this study, the mica used as a thermal-insulation material was modified with a silane coupling agent, octyltriethoxysilane (OTES), to improve its hydrophobicity. The modified mica was characterized using FT-IR spectrometer, water wettability test, and water contact angle measurement. The analysis exhibits that OTES for the modified mica sample was well bonded chemically and drastically enhanced the hydrophobicity. The reflectance observed as 73.9% (mica) and 86.4% (OTES/mica), respectively, for OTES/mica was improved about 12.5% before any modifications. Also the modified mica sample showed $7.2^{\circ}C$ decrease in the thermal-insulation performance of cool paints compared to that of using unmodified mica, indicating that the modification of mica with silane coupling agents could be effective in enhancing the thermal-insulation performance of the cool paint.

Failure Analysis of LV URD Cable based on FMEA (FMEA에 근거한 LV URD 케이블의 고장분석)

  • Shong, Kil-Mok;Han, Woon-Ki;Kim, Young-Seok;Kim, Sun-Gu;Kwak, Hee-Ro
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.5
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    • pp.90-98
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    • 2007
  • The objective of this investigation was to reveal the cause of the faulted cable(LV URD(low voltage underground) cable). For the analysis, various types or equipments such as external pattern, thermal pattern, surface structure, thermal analysis, and property distribution were deployed. The international standards and the specification provided by the manufacturer of faulted cable were examined whether it fit the standards. The summary is as follows. (1) Discovered as a factor lowering insulation performance of the faulted cable: minimum thickness of the insulation layer specified by IEC 60502-1 and IEC 60811-1-1 was not fit. (2) Infrared absorption peaks measured by FT-IR spectrometer revealed that the measurements made for the same material did not conform and it is an important basis for proving heterogeneous composition of the insulation material. (3) It was found that PVC bedding was thermally fragile and therefore long term exposure at the site could cause similar fault pattern.

Preparation of Water Repellent Polyurethane Coating Films Using Perfluoroalkyl Alcohol (과불화 알코올을 이용한 발수성 폴리우레탄 코팅 필름의 제조)

  • Kim, Nam Woo;Ahn, Chi Young;Song, Ki Chang
    • Korean Chemical Engineering Research
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    • v.54 no.3
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    • pp.387-393
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    • 2016
  • Fluorinated polyurethane coating solutions were synthesized from perfluoroalkyl alcohol, toluene diisocyanate, and polycarbonate diol as starting materials. Next, coating films were prepared by spin-coating the fluorinated polyurethane coating solutions on the PC substrates, followed by thermal curing at $120^{\circ}C$. The obtained fluorinated polyurethane coating films were characterized by FT-IR spectroscopy, UV-Vis spectrometer, contact angle tester and pencil hardness tester. Contact angle measurements of water on the coating films showed that the addition of perfluoroalkyl alcohol improved the water repellency and increased the contact angle from $81^{\circ}C$ to $111^{\circ}C$. However, the pencil hardness of coating films exhibited a constant grade of H, irrespective of the addition of perfluoroalkyl alcohol.