• Title/Summary/Keyword: Water film

Search Result 1,941, Processing Time 0.029 seconds

An Experimental study on Heat Transfer Characteristics of Horizontal Liquid Film Driven by Hot Wind (유동고온공기에 의해 유인되는 수평평판 액막류의 열전달에 관한 실험적 연구)

  • Park, J.H.;Park, S.K.;Yoon, S.H.;Oh, C.;Kim, M.H.
    • Proceedings of the Korean Society of Marine Engineers Conference
    • /
    • 2002.05a
    • /
    • pp.83-88
    • /
    • 2002
  • This study is to provide the experimental information and basic data on heat transfer characteristics of horizontal liquid film driven by hot wind. Heat transfer characteristics of the liquid film in the rectangular duct was observed and the change of film temperature was measured. The experiments were carried out for a variety of parameter, such as feed water rate and velocity and temperature of feed air. From the observation and the measurement the general understanding of heat transfer characteristics for liquid film driven by hot wind was provided.

  • PDF

Hafnium Oxide Nano-Film Deposited on Poly-Si by Atomic Layer Deposition

  • Wei, Hung-Wen;Ting, Hung-Che;Chang, Chung-Shu
    • 한국정보디스플레이학회:학술대회논문집
    • /
    • 2005.07a
    • /
    • pp.496-498
    • /
    • 2005
  • We reported that high dielectric hafnium oxide nano-film deposited by thermal atomic layer deposition on the poly-silicon film (poly-Si). The poly -Si film was produced by plasma enhanced chemical vapor deposition and excimer laser annealing. We used the hafniu m chloride ($HfCl_4$) and water as the precursors and analyzed the hafnium oxide film by transmission electron microscope and secondary ion mass spectrometer. Hafnium oxide produced by the ALD method showed very good coverage on the rough surface of poly-Si film. While deposited with 200 cycles, these hafnium oxide films revealed a relatively smooth surface and good uniformity, but the cumulative roughness produced by the incomplete reaction was apparent when the amount of deposition cycle increased to 600 cycles.

  • PDF

Analysis on the Drying Characteristics for the Drying Process of a Thin Film Layer of Sludge (슬러지 박막의 건조과정에 대한 건조 특성 해석)

  • Lee, Kong-Hoon;Kim, Ook-Joong
    • Proceedings of the SAREK Conference
    • /
    • 2008.06a
    • /
    • pp.1128-1133
    • /
    • 2008
  • Drying process in the thin film layer of sludge with the thickness less than a few millimeters has been investigated using the simple one-dimensional model. Thin film drying is usually used to dry the viscous materials like sewage sludge. The thin film layer of sludge is dried on the metallic surface through which thermal energy is supplied to the layer during drying. In order to solve the equations, the mass transfer rate on the drying surface should be determined. The mass flux of evaporated water vapor on the surface is estimated with the formulation given in the literature. The effect of heating temperature, film thickness, and air velocity on drying has been examined to figure out the drying characteristics of the sludge layer.

  • PDF

Preparation of TiO2 Nanotube Arrays from Thin Film Grown by RF Sputtering

  • Kim, Chang Woo
    • Applied Science and Convergence Technology
    • /
    • v.27 no.5
    • /
    • pp.105-108
    • /
    • 2018
  • Transparent $TiO_2$ nanotube arrays are successfully prepared by a two-step approach involving electrochemical anodization and RF magnetron sputtering. First, a Ti film is deposited on an FTO substrate by RF magnetron sputtering at room temperature. The morphologies of the Ti film are controlled by the working distance, Ar flow, and DC power. Second, an anodization treatment is electrochemically performed for the formation of nanotube arrays from the deposited Ti film, followed by post-annealing treatment in air for the formation of $TiO_2$ crystallization. The back side of the crystallized $TiO_2$ nanotube arrays is illuminated with solar light to characterize the photoelectrochemical reaction, and their photoelectrochemical properties are investigated. This work provides information on application of a thin film deposited by RF sputtering in the field of photoelectrochemical water splitting.

Reliability Evaluation of Atomic layer Deposited Polymer / Al2O3 Multilayer Film for Encapsulation and Barrier of OLEDs in High Humidity and Temperature Environments (OLED Barrier와 Encapsulation을 위한 원자층 증착 Polymer / Al2O3 다층 필름의 온습도 신뢰도 평가 분석)

  • Lee, Sayah;Song, Yoon Seog;Kim, Hyun;Ryu, Sang Ouk
    • Journal of the Semiconductor & Display Technology
    • /
    • v.16 no.4
    • /
    • pp.1-4
    • /
    • 2017
  • Encapsulation of organic based devices is essential issue due to easy deterioration of organic material by water vapor. Atomic layer deposition (ALD) is a promising solution because of its low temperature deposition and quality of the deposited film. Moisture permeation has a mechanism to pass through defects, Thin Film Encapsulation using inorganic / organic / inorganic hybrid film has been used as promising technology. $Al_2O_3$ / Polymer / $Al_2O_3$ multilayer film has shown excellent environmental protection characteristics despite of thin thicknesses of the films.

  • PDF

Effect of Surface Modification by Solvent Treatment on Morphology and Radionuclide Pick-up Efficiency of Polysulfone Film (폴리설폰 필름의 형상 및 방사성 오염물 채취에 있어 용매처리의 효과)

  • 한명진;이근우;서범경;박진호;남석태
    • Membrane Journal
    • /
    • v.14 no.2
    • /
    • pp.126-131
    • /
    • 2004
  • The surface of dense polysulfane films was modified through solvent treatment. The modification process consisted of dipping a film for one second in dimethylformamide and then immersing it Into a nonsolvent bath. After being solidified, the original transparent film transformed into an opaque white one, which is due to the light scattering on pores newly developed on the surface. The surface roughness entailing the pore formation was more explicit on a film coagulated by water as nonsolvent than on a film coagulated by isopropanol. The surface-modified films show the better pick-up efficiency than a conventional filter paper on the detaching of radioactive contaminants on the contaminated area. The pick-up efficiency of the film prepared by the water immersion process was superior to that of the film prepared in the isopropanol bath, which was consistent with the surface roughness result. The surface-modified films kept the dense inner structure, playing a major role preventing a possible secondary contamination during the pick-up process.

Antimicrobial Activity and Food Storage of LDPE Silica Film Containing Antimicrodial Compounds (항균성물질이 함유된 Silica LDPE필름의 항균효과 및 식품 저장성)

  • 김현수;성림식;이인선
    • KSBB Journal
    • /
    • v.17 no.4
    • /
    • pp.350-356
    • /
    • 2002
  • Low density polyethylene(LDPE) film was fabricated with the addition of benzoic acid, or/and JP which contained water-soluble silica adsorbed a natural antimicrobial compounds. The used antimicrobial compounds were isolated from culture broths of methylotropic actinomycetes strains MO-16 and MO-17 which was newly isolated from soils. An antimicrobial compound retained antimicrobial activity after heat treatment at 121$^{\circ}C$ for 5 min. JP, which obtained from Japan as a antimicrobial agent, showed antimicrobial activity in the concentration of 100 mg/mL. The silica LDPE film revealed the growth inhibition of total aerobic bacteria in packaged minced pork compared with commercial film and of E. coil on a contained agar plate. In the storage testing of various packaged foods at room temperature for 30 days, the film showed excellent preservation compared with commercial film in case of small tomato and Agaricus bisporus.

Comparison of tear film break-up time and high order aberration according to soft contact lens material (소프트콘택트렌즈 재질에 따른 눈물막 파괴시간과 고위수차의 비교)

  • Kim, Bong-Hwan;Han, Sun-Hee;Kim, Hak-Jun;Bae, Sang-A;Son, Yu-Jin;Kim, Ji-Hyun;KIm, Hyun-Ji
    • Journal of Korean Clinical Health Science
    • /
    • v.7 no.1
    • /
    • pp.1232-1237
    • /
    • 2019
  • Purpose. In this study, two types of soft contact lenses with different materials were selected to compare the time of tear film destruction and high order aberrations before and after wearing. Methods. Thirty patients (60 eyes) in their 20s were included in this study. Two lenses with different materials, Group 4 (Etafilcon A) and Group 5 (Narafilcon A) were selected. Using aberration analyzer and keratometry, high-order aberration and tear film test (NIF-BUT, NIAvg-BUT) were performed before and after wearing. Results. When comparing the higher aberrations of the Etafilcon A and Narafilcon A lenses, the higher aberrations of the Narafilcon A lens were higher overall. For the initial tear film break-up time (NIF-BUT) after wearing, the Etafilcon A lens was reduced by 4.0 seconds and the Narafilcon A lens increased by 0.6 seconds. For the mean tear film break-up time (NIAvg-BUT) after wearing, the Etafilcon A lens decreased by 2.4 seconds and the Narafilcon A lens increased by 1.7 seconds. Conclusions. NIF-BUT and NIAvg-BUT of Narafilcon A lens were increased. The lens with relatively low water content and higher oxygen permeability than the lens with high water content has relatively less tear evaporation, which means that the time of destruction of the tear film is increased.

Corrosive Wear of Alloy 690 Tubes in Alkaline Water

  • Hong, Seung Mo;Jang, Changheui;Kim, In Sup
    • Corrosion Science and Technology
    • /
    • v.8 no.3
    • /
    • pp.126-131
    • /
    • 2009
  • The interaction between wear and corrosion can significantly increase total material losses in water chemistry environment. The corrosive wear tests of a PWR steam generator tube material (Alloy 690) against the anti vibration bar material (409 SS) were performed at room temperature. The tests were performed in alkaline water chemistry conditions. NaOH solution was selected for test condition to investigate the corrosive wear effect of steam generator tube material in alkaline pH condition without other factors. The flow induced vibration can caused tube damage and the corrosion can be occurred by water chemistry. The test results showed that, in the alkaline solution at pH 13.9, the corrosion current density was increased about ten times than that in the distilled water. And wear rate at pH 13.9 was increased about ten times from that at neutral condition. However, the wear rate was decreased with time. The decrease would be attributed to the change in roughness of specimen or sub-layer of the worn surface with time. From microstructure observation, severe abrasive shape and several wear debris were found. From those results, it could infer that the oxide film on Alloy 690 changed to easily breakable one in the alkaline water, and then abrasion with corrosion became the main wear mechanism.

A Foundamental Study on the Solvent Dyeing Part 1. Change of PET Substrate Treated with Water, TCE and Water/TCE Emulsion. (용제염색에 관한 기초적 연구 제일보 물, TCE 및 물/TCE 처리에 의한 PET 기질의 변화)

  • Chung Doo Jin
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.2 no.2
    • /
    • pp.245-252
    • /
    • 1978
  • In order to obtain some information for solvent dyeing, polyethylene terephthalate (PET) was treated with water, tetrachloroethylene yarn (TCE), and water/TCE emulsion for three hours at the temperatures from $40^{\circ}$ to $140^{\circ}C$. The change of fine structure of substratum by measuring the shrinkage, the degree of crystallinity, the stress relacxation modulus and Young's modulus. The P.E.T. film was also treated in water (at $140^{\circ}C$) for 4 hours to stabilize the substratum. By means of film roll cyliderical method, the Disperse Blue 27 was diffused. Then, calculated the diffusion coefficient and examined the application of WLF equation. However, the temperature dependence of the shrinkage could be explain with WLF equation, the diffusion coefficient couldn't be applied the WLF equation when the substratum was stabilized. From the result, the effects on shrinkage were in the order of water

  • PDF