• Title/Summary/Keyword: Gaseous

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Photocatalytic Degradation of Acetaldehyde and MEK using Batch Type Photo-Reactor (회분식 광촉매반응기를 이용한 아세트알데하이드와 MEK 제거특성 연구)

  • Cha, Wang Seog
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.3
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    • pp.1527-1532
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    • 2013
  • The kinetics of photocatalytic degradation of gaseous acetaldehyde and methylethylketone(MEK) were studied by the batch scale of photo-reactor. Variable parameters were initial concentration of acetaldehyde and MEK, water vapor content, and temperature. The photocatalytic degradation rate was increased with increasing concentration of acetaldehyde and MEK, but maintained gentle increase beyond a certain concentration. The Langmuir-Hinselwood model was successfully applied to correlate experimental data. Water vapor inhibited the degradation reaction of acetaldehyde and MEK. The optimum reaction temperature was $45^{\circ}C$ for acetaldehyde and MEK.

Breakdown Properties for Electrical Insulation Design of Double Pancake Coil Type HTS Transformer (Double Pancake Coil형 고온초전도 변압기의 전기적 절연 설계를 위한 절연파괴 특성)

  • Baek, Seung-Myeong;Jung, Jong-Man;Kim, Sang-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.08a
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    • pp.52-57
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    • 2002
  • High temperature superconductors can only be applied against an engineering specification that has to be determined for each particular application form the design requirements for economic viability and for operation margins in service. However, in order to realize the HTS transformer, it is necessary to establish the high voltage insulation technique in cryogenic temperature. Therefore, the composite insulation of double pancake coil type transformer are described and ac breakdown voltage characteristics of liquid nitrogen($LN_{2}$) under HITS pancake coil electrode made by Bi-2223/Ag are studied. Breakdown in $LN_{2}$ is dominated electrode shape and distance. And we investigated AC breakdown properties of $LN_{2}$ and complex conition of cryogenic gaseous nitrogen($CGN_{2}$) obove a $LN_{2}$ surface. Also, the surface voltage of GFRP was measured as a function of thickness and electrode distance in $LN_{2}$ and complex condition of $CGN_{2}$ above a $LN_{2}$ surface. This research presented information of electrical insulation design for double pancake coil type HTS transformer.

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Study of Counter Diffusion in Isostatic Permeameters

  • Bianchi, F.;Pegoraro, M.;Zanderighi, L.
    • Korean Membrane Journal
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    • v.3 no.1
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    • pp.39-50
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    • 2001
  • The counter-diffusion of two gaseous substances permeating a polymeric membrane has been investigated both experimentally and theoretically. The aim of the study was to find mutual effects, if any, that could influence the permeability and diffusivity data. The experimental data were obtained with an isostatic permeameter operating at ambient pressure and 303 K: helium, nitrogen, carbon dioxide methane were used as permeating gas at different partial pressure; helium or nitrogen as equilibrating or carrier gas. No evident mutual effect of the counter-diffusing gas was observed. The theoretical analysis gave some insight into the phenomena and it was concluded that at near-atmospheric pressures, and in the absence of swelling phenomena no mutual interaction exists. On a theoretical basis any mutual interaction between diffusing and counter-diffusing gases could only occur: i) at high pressures , when the free movement of permeating gas molecules within the polymer is hindered by the counter-diffusing gas; ii) when a large part of the free volume fraction is occupied by the counter--diffusing gas; iii) swelling phenomena modify the structure and free volume fraction of the polymer.

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Method for expanding tobacco leaves with steam at high temperature and velocity (고온 증기를 이용한 잎담배의 팽화연구)

  • 김병구;김기환;정한주;유광근;이태호
    • Journal of the Korean Society of Tobacco Science
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    • v.17 no.1
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    • pp.68-78
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    • 1995
  • A study of expanding tobacco includes the steps of adjusting the moisture content of cut tobacco, without the use of exogenous impregnants by contacting the filler with a high velocity gaseous medium at elevated temperature such that heat is rapidly and substantially uniformly transferred from the medium to the filler for a total contact time sufficient to expand the tobacco leaves. Study is disclosed for drying and expanding cut tobacco by introducing the tobacco into an elongated tubular shaped conduit through which steam high temperature 150-35$0^{\circ}C$ and high velocity above the 18m1sec, super steam is recycled. moisture content of shreded tobacco leaves, immediately before treatment within the range of from 10% to 24% and, most preferably, within the range of from 18% to 21%. Expanding rate showed 70% in NC -82(B.3) and 42% in Burley -21(B.1) which is produced in 1993 under this condition. When expanding tobacco expanded tobacco did not change significally, but they were decreased at 27$0^{\circ}C$ very largely. The curtailment of cost price and physical and chemical properties of various items were improved in cigarettes. Key words : Expanding tobacco, Super steam tobacco expansion, Fast drying tobacco, High temperature treat tobacco, Puffing tobacco.

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A Case of Gastric Adenoma in a Maltese Dog (말티즈 견에서 발생한 위 선종 증례)

  • Eom, Na-Young;Lee, Hee-Chun;Lee, Seung-Yong;Jang, Hyo-Mi;Sur, Jung-Hyang;Jung, Dong-In
    • Journal of Veterinary Clinics
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    • v.32 no.4
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    • pp.370-373
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    • 2015
  • A 10-year-old, intact female, Maltese dog was presented with a two weeks history of vomiting, anorexia and weight loss. Hematologic analysis revealed mild leukocytosis and increased liver enzyme. Gaseous dilation of small intestine and hyperechoic nodules of hepatic lobes were revealed on the imaging studies. Liver biopsy was performed through laparotomy and histopathologic results revealed liver cirrhosis with precancerous lesions. Two days later, endoscopy was performed and histopathologic results of the specimens taken by endoscopic biopsy showed gastric adenoma. The gastric surgery was not performed by the owner's request. The patient died after 60 days of diagnosis of gastric adenoma. This case describes clinical features, imaging studies, endoscopic features and histopathologic characteristics of gastric adenoma in a Maltese dog.

Physico-chemical properties between organic and conventional kiwifruit orchards in Korea

  • Cho, Y.;Kim, B.;Cho, H.;Jeong, B.
    • Korean Journal of Organic Agriculture
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    • v.19 no.spc
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    • pp.242-246
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    • 2011
  • Organic kiwifruit orchard soils were compared with conventional ones in Korea. Soil structure of organic soil had higher gaseous and liquous phase as well as soil porosity in the surface soil. Although the nutritional level of each orchards were quite different among soils, the analysis of both system revealed that organic kiwifruit orchard soil had similar or even higher nutrient level (N and organic matter content in surface soil) compared to conventional ones. The organic matter content of deep soil also had the high tendency in deep soil of organic soil. Higher level of nitrogen in organic surface soil is presumably due to the excessive application of organic compost and liquid fertilizer rather than the contribution by grasses such as green manure. Available phosphorous level of organic system was quite high but similar in surface soil of both system, compared to the recommended level. Potassium, calcium and magnesium levels were also enough in organic kiwifruit orchard soils.

THE DEVELOPMENT OF THE EM-$200^{TM}$ GAS-FILLED AFFF FIRE EXTINGUISHER FOR AUTOMATIC FIRE SUPPRESS10N SYSTEMS IN THE ENGINE COMPARTMENT OF AUTOMOBILES

  • Jung, Ki-Chang;Kim, Hong;Kang, Young-Goo
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 1997.11a
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    • pp.598-605
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    • 1997
  • In recent years, the number of vehicle fires, as well as the number of motor vehicles, has been increasing rapidly. Therefore, several types of automatic fire suppression systems for the engine compartment of automobiles have been developed to extinguish automobile fires, and most of these systems use halon 1301 as a fire extinguishing agent. Due to environmental concerns, the phase-out of halons has been announced, so now there is a need to replace halon 1301. For this, a 1,1,1,2,3,3,3-heptaflouropropane (HFC-227ea, FM-$200^{TM}$) gas-filled Aqueous Film- Forming foam (known as AFFF) extinguisher was devised even though air foam extinguishers could be used. This is because the air in the foam bubbles is a source of oxygen required for the combustion reaction. It can be surmised that it is possible to increase the fire extinguishing efficiency of AFFF by filling in foam bubbles with a gaseous extinguishing agent. The best choice is the FM-$200^{TM}$ gas-filled AFFF, Which has the maximum expansion ratio of 62:1. This makes it possible for the expanded foam to rapidly fill the engine compartment.

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A Study on Adhesive Properties of Cellulose Triacetate Film by Argon Low Temperature Plasma Treatment (아르곤 저온 플라즈마 처리에 의한 CTA 필름의 접착성 연구)

  • Koo Kang;Park Young Mi
    • Textile Coloration and Finishing
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    • v.16 no.5
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    • pp.28-34
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    • 2004
  • The polarizing film application exploits the unique physicochemical properties between PVA(Poly vinyl alcohol) film and CTA(Cellulose triacetate) film. However, hardly any research was aimed at improving the adhesion characteristics of the CTA film by radio frequency(RF) plasma treatment at argon(Ar) gaseous state. In this report, we deal with surface treatment technology for protective CTA film developed specifically for high adhesion applications. After Ar plasma, surface of the films is analyzed by atomic force microscopy(AFM), roughness parameter and peel strength. Furthermore, the wetting properties of the CTA film were studied by contact angle analysis. Results obtained for CTA films treated with a glow discharge showed that this technique is sensitive to newly created physical functions. The roughness and peel strength value increased with an increase in treatment time for initial treatment, but showed decreasing trend for continuous treatment time. The result of contact angle measurement refer that the hydrophilicity of surface was increased. AFM studies indicated that no considerable change of surface morphology occurred up to 3 minutes of treatment time, but a considerable uneven of surface structure resulted from treating time after 5 minutes.

Study on Preparation of Metal Phthalocyanine Derivative Langmuir-Blodgett Film (금속 프탈로시아닌 유도체의 Langumuir-Blodgett 박막 제작에 관한 연구)

  • Shin, Hyun-Man;Ha, Yun-Kyung;Kim, Young-Kwan;Sohn, Byoung-Chung
    • Journal of the Korean Applied Science and Technology
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    • v.14 no.3
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    • pp.89-95
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    • 1997
  • It is well known that the metallo-phthalocyanine(MPcs) are sensitive to toxic gaseous molecules such as $NO_2$ and also chemically and thermally stable. Therefore, lots of MPcs have been studied for the potential chemical sensor for $NO_2$ gas using quartz crystal microbalance or electrical conductivity. In this study, 2,3,9,10,16,17,23,24-[octa-(dodecyloxy)] copper phthalocyanine and 2,3,9,10,16,17,23,24-[octa-(octyloxy)] copper phthalocyanine were synthesized and their possibility of LB film preparation were tested. It was confirmed by using FT-IR, DSC, NMR, UV-Vis absorption spectroscopy and Elemental Analysis that CuPc derivatives were successfully synthesized. From the ${\pi}$-A characteristics and limiting areas of two CuPc derivatives it was found that the preparation of LB films with these CuPc derivatives is possible.

The Stopping Power and Cross-section Measurement of $\alpha$-particle in Ar, He and $N_2$ gases (Ar, He 및 $N_2$ 가스의 $\alpha$-입자 저지능과 저지 단면적 측정)

  • Lee, Jung-Hoon;Hwang, Jae-Kwang;Hwang, Han-Yull;Chung, Won-Mo;Joo, Koan-Sik
    • Journal of Radiation Protection and Research
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    • v.13 no.2
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    • pp.1-8
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    • 1988
  • The energy losses of ${\alpha}$-particle with 3 to 5.4 MeV energy were measured as a function of gas absorber thickness and ${\alpha}$-particle energy in three light gaseous media; He, Ar, and $N_2$. The stopping powers and stopping cross-sections were determined by analyzing these data. For Ar gas, the experimental values are very well consistent with the corresponding values of Srivastava's stopping-power theory with the condition of the completely and partially stripped ion. For $N_2$ and He gases, these experimental values express the inconsistencies of about $13{\sim}36%$ and $27{\sim}28%$, respectively.

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