• Title/Summary/Keyword: Water film

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Effect of Radish Extract on the Growth of Food-born Microorganisms (무 추출물이 식품관련 미생물의 증식에 미치는 영향)

  • 곽희진;계수경;곽희선;이경혜
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.4
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    • pp.288-297
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    • 2000
  • To understand the effect of radish on growth of food born microorganisms, mashedflesh radishes were extracted by using acetone and distilled water. Their effect was assayed by measuring the optical density of cultural broth of food born microorganisms. In the experiment, seven strains of yeast were used as the test organism. Acetone extract inhibited growth of the cells of L. plantarum, L. sake and Danmuji film yeast. Growth of the film yeast was drastically inhibited in the concomitant presence of 0.03% extract, while other microbes such as L. faecalis, P. pentosaceus, B/ subtilis and E. coli grew by succeeding cultivation for 4 to 8 hour after addition of the extract. Water extract, on contrast to acetone extract, at he concentrations of 0.1∼1.5% stimulated the growth of lactic acid bacteria. Culture of L. faecalis and L. sake showed an optical density higher than that of control by 40∼50 times. The effect was not so apparent against E. coli, S. aureus and Danmuji film yeast.

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Characteristics of Heat and Mass Transfer for a Falling Film Type Absorber with Insert Spring Tubes (스프링삽입형 유하액막식 흡수기의 열 및 물질전달 특성)

  • 윤정인;오후규;백목효부
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.6
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    • pp.1501-1509
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    • 1995
  • It is known that the heat and mass transfer characteristics in the absorber are most sensitive of the temperature boost of all the heat exchangers and the development of a more efficient absorber should be highly important. This paper describes absorption experiments made with different inside tube diameters, tube length and tube shapes. The purpose of this study is to acquire basic knowledge about heat and mass transfer in a falling film type absorber with vertical inner tubes. Heat and mass transfer were measured for water vapor absorption into a Lithium Bromide-water solution flowing down an absorber of vertical inner tubes. As a result, insert spring tube compares bare tube and heat transfer improved by order of insert spring tube P2(pitch 20 mm) and P1(pitch 10 mm).

Fabrication of He-Ne ellipsometer and in-situ measurement of effective density variation of $TiO_2$thin films (보급형 He-Ne 타원해석기의 제작과 $TiO_2$ 박막 유효밀도 변화의 in-situ 측정)

  • 김상준;방현용;김상열
    • Journal of the Korean Vacuum Society
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    • v.8 no.4A
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    • pp.432-437
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    • 1999
  • We have fabricated an in situ ellipsometer operating at He-Ne wavelength. It can be applied to the real-time, in-situ tracking of the ellisometric change which occurs during various sample treatments. As a rotating analyzer type, all optical elements and related parts are designed to share a common hollow-axis configuration, and hence the ellipsometer is compact in shape and simple in design. It is mountable on the spare ports of vacuum chamber with ease. Using this ellipsometer, we observed the effective density variation of previously grown $TiO_2$ thin films by using electron beam evaporation. The packing density of the as-grown film was 82%. When exposed to atomsphere, the micro-void of the film was filled with water vapor. This water-filled $TiO_2$ thin film was subject to heating/cooling cycles in vacuum and the ellipsometric variation versus temperature and cycling number was measured in real time using this in situ He-Ne ellipsometer.

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Excimer Laser Micromachining of Polymers Assisted by Liquid (액체 보조 방식의 Excimer 레이저 폴리머 미세가공)

  • Jang, Deok-Suk;Kim, Dong-Sik
    • Laser Solutions
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    • v.10 no.1
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    • pp.19-27
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    • 2007
  • Previous studies demonstrated that laser ablation under transparent liquid can result in ablation enhancement and particle removal from the surface. Although the ablation enhancement by liquid is already known for semiconductor and metal, the phenomena of polymer ablation have not been studied. In this work, tile liquid-assisted excimer laser ablation process is examined for polymer materials, such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) with emphasis on ablation enhancement and surface topography. In the case of PET and PMMA, the effect of liquid is analyzed both for thin water film and bulk water. The results show that application of liquid increases the ablation rate of PMMA while that of PET remains unchanged even in the liquid-assisted process. However, the surface roughness is generally deteriorated in the liquid-assisted process. The surface topography is found to be strongly dependent on the method of liquid application, i.e., thin film or bulk liquid.

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Fabrication and Response Characteristics of Multi-walled Carbon Nanotube Film Humidity Sensor (다중벽 탄소나노튜브 습도센서의 제작과 응답특성)

  • Park, Chan-Won
    • Journal of Industrial Technology
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    • v.34
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    • pp.39-43
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    • 2014
  • This paper represents a highly porous MWCNT film electrode with interconnected open pores and demonstrated the possibility of using an MWCNT network film as the top electrode for polyimide capacitive humidity sensors. Polyimide humidity sensors with MWCNT electrodes exhibited about 6 times faster response than equivalent Cr electrode sensors. This result may be due to their percolated pore structures, which make water molecules accessible to all polyimide surfaces. The much faster response times of MWCNT electrode sensors is attributed to the percolated pore network, which allows more water molecules to be accessible to polyimide surfaces.

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Study on Correlation of Droplet Flow Rate and Film Boiling Heat Transfer in Spray Cooling (액적 유량과 분무냉각 막비등 열전달의 상관관계에 관한 연구)

  • Yun, Seung-Min;Kim, Yeung-Chan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.4
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    • pp.335-340
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    • 2007
  • A new correlation between the Nusselt number based on modified heat transfer coefficient and Reynold number based on droplet-flow-rate was developed for the experimental data. The modified heat transfer coefficient was defined as ratio of wall heat flux to droplet subcooling. In the previous reports, the local heat flux of spray cooling in the film boiling region was experimentally investigated for the water spray region of $D_{max} = 0.0007{\sim}0.03m^3/(m^2s)$ . In the region near the stagnation point of spray flow, a new heat transfer correlation is recommended which shows good predictions for the water spray region of $D_x{\le}0.01m^3/(m^2s)$.

m-Aramid Films in Diverse Coagulants

  • Kim, Ji-Young;Jung, Ji-Won;Kim, Sam-Soo;Lee, Jae-Woong
    • Textile Coloration and Finishing
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    • v.21 no.4
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    • pp.63-67
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    • 2009
  • m-Aramid dissolved in N,N-dimethylacetamide (DMAc), were coagulated in different coagulants such as water, methanol, ethanol, propanol and butanol. Various concentrations and temperatures of the coagulants were also used to evaluate dyeing properties of coagulated m-aramid films. Field emission scanning electron microscopy (FE-SEM) was employed to investigate the surface morphology of m-aramid films. Wide angle X-ray diffraction (WAXD) was conducted in order to measure crystallinity change of mcaramid fibers and films. WAXD patterns showed that crystallinity of m-aramid fibers was reduced after film formation. In addition, color depth (K/S value) was measured and the results revealed that the film coagulated in water possessed fairly enhanced color depth.

Three-Dimensional Nanofabrication with Nanotransfer Printing and Atomic Layer Deposition

  • Kim, Su-Hwan;Han, Gyu-Seok;Han, Gi-Bok;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.87-87
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    • 2010
  • We report a new patterning technique of inorganic materials by using thin-film transfer printing (TFTP) with atomic layer deposition. This method consists of the atomic layer deposition (ALD) of inorganic thin film and a nanotransfer printing (nTP) that is based on a water-mediated transfer process. In the TFTP method, the Al2O3 ALD growth occurs on FTS-coated PDMS stamp without specific chemical species, such as hydroxyl group. The CF3-terminated alkylsiloxane monolayer, which is coated on PDMS stamp, provides a weak adhesion between the deposited Al2O3 and stamp, and promotes the easy and complete release of Al2O3 film from the stamp. And also, the water layer serves as an adhesion layer to provide good conformal contact and form strong covalent bonding between the Al2O3 layer and Si substrate. Thus, the TFTP technique is potentially useful for making nanochannels of various inorganic materials.

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Development of Plastic Film Type Submersion Sensor (플라스틱 필름형 침수센서 개발)

  • Lee, Young Tae;Kwon, Ik Hyun
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.2
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    • pp.107-111
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    • 2022
  • In this paper, a plastic film type submersion sensor capable of measuring submersion speed was developed. This submersion sensor is designed as a capacitive type, and it is a sensor that outputs the change in capacitance between the electrode of the submersion sensor and the grounded body as a voltage through a C-V(capacitance-voltage) converter. We developed an submersion sensor in which two electrodes of different lengths are connected in parallel to measure the submersion speed accurately by minimizing the influence of noise such as contamination. When both electrodes of the submersion sensor are exposed to water, the rate of change of water level suddenly increases, so the submersion speed is measured by measuring the time to this point. Since the difference in length between the two electrodes of the submersion sensor does not change in any case, it is possible to accurately measure the submersion speed.