• Title/Summary/Keyword: film density

Search Result 2,367, Processing Time 0.027 seconds

Effect of Double-Cropping Systems on Nematode Population in Plastic Film House Soils of Oriental Melon Cultivation (이모작에 따른 참외 재배 비닐하우스 토양의 선충밀도 변화)

  • Byeon, Il-Su;Suh, Sun-Young;Lee, Yong-Se;Chung, Jong-Bae
    • Korean Journal of Environmental Agriculture
    • /
    • v.33 no.1
    • /
    • pp.17-23
    • /
    • 2014
  • BACKGROUND: Crop rotation is often used as a solution to eradicate nematodes in soils used in plastic film houses for long-term cultivation of oriental melon. However, it is not clear if the double-cropping is effective in reducing nematode populations in soils. METHODS AND RESULTS: Nematode population in plastic film house soil was measured during oriental melon cultivation from April to July in short term crop rotation systems of oriental melon. Double-cropping of chinese cabbage in open-field for 3-4 months following oriental melon in plastic film houses could not prevent the build-up of high population density of nematodes. However, double-cropping of dropwort in flooded soil for 3-4 months following oriental melon in plastic film houses could effectively reduce the nematode population during the successive year of oriental melon cultivation. The reduced nematode population in soils of oriental melon-dropwort double-cropping system was continued until the mid season of progressive year oriental melon cultivation. Application of nematicide to soil before growing oriental melon in the oriental melon-dropwort double-cropping was very effective in preventing the build-up of high population density of nematode in plastic film house soils. CONCLUSION: Short-term introduction of crop rotation was not effective in suppression of high population density of nematodes in plastic film house soils of long-term year-to-year production of oriental melon. For securing the soil productivity and sustainability of plastic film house, various physical, chemical, and agronomic practices should be properly combined together.

Effect of Corona Discharge Treatment on the Dyeability of Low-density Polyethylene Film

  • Park, Soo-Jin
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2003.10a
    • /
    • pp.35-36
    • /
    • 2003
  • The purpose of this work is to investigate the surface modification of LDPE film via corona discharge treatment and subsequent graft polymerization, and their effect on the resulting dyeability is studied in terms of the surface functional groups, surface energetics, and acid-base interaction between the modified LDPE and the dyes used.

  • PDF

Characterization of Thin Liquid Films Using Molecular Dynamics Simulation

  • Lee, Jaeil;Park, Seungho;Ohmyoung Kwon;Park, Young-Ki;Lee, Joon-Sik
    • Journal of Mechanical Science and Technology
    • /
    • v.16 no.11
    • /
    • pp.1477-1484
    • /
    • 2002
  • Various characteristics of a thin liquid film in its vapor-phase are investigated using the molecular dynamics technique. Local distributions of the temperature, density, normal and tangential pressure components, and stress are calculated for various film thicknesses and temperature levels. Distributions of local stresses change considerably with respect to film thicknesses, and interracial regions on both sides of the film start to overlap with each other as the film becomes thinner. Integration of the local stresses, i.e., the surface tension, however, does not vary much regardless of the interfacial overlap. The minimum thickness of a liquid film before rupturing is estimated with respect to the calculation domain sizes and is compared with a simple theoretical relation.

Analysis of the Light Environment in Model Greenhouse using Infrared Absorption Film as Shading Screen (적외선 흡수필름을 차광재로 사용한 모형 온실의 광환경 분석(농업시설))

  • 권혁진;김기성;김문기
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2000.10a
    • /
    • pp.340-345
    • /
    • 2000
  • This study was carried out to analyze the light and thermal environment in model greenhouse using infrared absorption film as shading screen and to compare with the case of no shading and using general shading screen such as aluminum foil-backed film, black polyethylene film and thermal blanket. PPFD(photosynthetic photon flux density) of inside the model greenhouse under infrared absorption film was increased by 22% than under general shading screen on the average. And temperature of inside air under infrared absorption film was 2$^{\circ}C$ lower than under general shading screen on the average. So, it is expected that infrared absorption film is useful as shading screen.

  • PDF

Sol-gel Spin-coating of ZnO Co-doped with (F, Ga) as A Transparent Conducting Thin Film ((F, Ga) 코도핑된 ZnO 투명 전도 박막의 솔-젤 제조와 특성)

  • Nam, Gil Mo;Kwon, Myoung Seok
    • Journal of the Semiconductor & Display Technology
    • /
    • v.13 no.1
    • /
    • pp.91-95
    • /
    • 2014
  • (F,Ga) co-doped ZnO thin film on glass substrate was fabricated via a simple non-alkoxide sol-gel spin-coating. Contrary to the F single doped ZnO thin film, the (F,Ga) co-doped thin film showed a significant reduce in electrical resistivity after a second post-heat-treatment in reducing environment. The resulting decrease in electrical resistivity with Ga co-doping is considered to be resulted from the increases both carrier density and mobility. The optical transmittance of the (F,Ga) co-doped thin film in the visible range showed higher transmittance with Ga co-doping compared with F single doped ZnO thin film.

Evaluation of Characteristics of Oxidized Thin LPCVD-$Si_{3}N_{4}$ Film (얇은 열산화-질화막의 특성평가)

  • 구경완;조성길;홍봉식
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.29A no.9
    • /
    • pp.29-35
    • /
    • 1992
  • Dielectric thin film of N/O (Si$_{3}N_[4}/SIO_{2}$) for high density stacked dynamic-RAM cell was formed by LPCVD and oxidation(Dry & pyrogenic oxidation methods) of the top Si$_{3}N_[4}$ film. The thickness, structure and composition of this film were measured by ellipsometer, high frequency C-V meter, high resolution TEM, AES, and SIMS. The thickness limit of Si$_{3}N_[4}$ film in making thin N/O structure layer was 7nm. In this experiment, the film with thinner than 7nm was not thick enough as oxygen diffusion barrier, and oxygen punched through the film and interfacial oxidation occurred at the phase boundary between Si$_{3}N_[4}$ and polycrystalline silicon electrode.

  • PDF

Mechanical and Water Barrier Properties of Biopolyester Films Prepared by Thermo-Compression

  • Rhim, Jong-Whan
    • Food Science and Biotechnology
    • /
    • v.16 no.1
    • /
    • pp.62-66
    • /
    • 2007
  • Four different biopolyester films, two aliphatic polyesters including polylactides (PLA) and poly(3-hydroxy-butyrate-co-3-hydroxyvalerate (PHBV), and two aliphatic-aromatic copolyesters including Ecoplex and Biomax, were prepared using by thermo-compression, and their tensile and water barrier properties were determined. Among the films tested, PLA film was the most transparent (T: 95.8%), strongest, and stiffest (TS, 40.98 MPa; E, 1916 MPa), however it was rather brittle. In contrast, Ecoplex film was translucent while being the most flexible and resilient (EB, 766.8%). Biomax film was semitransparent and was the most brittle film tested (EB, 0.03%). All biopolyester films were water resistant exhibiting very low water solubility (WS) values ranging from 0.0.3 to 0.36%. PHBV film showed the lowest water vapor permeability (WVP) value ($1.26{\times}10^{-11}\;g{\cdot}m/m^2{\cdot}sec{\cdot}Pa$) followed by Biomax, PLA, and Ecoflex films, respectively. The water vapor barrier properties of each film were approximately 100 times higher than those of carbohydrate or protein-based films, but about 100 times lower than those of commodity polyolefin films such as low-density polyethylene (LDPE) or polypropylene (PP).

A study on patterning of photosensitive polyimide LB film (감광성 polyimide LB막의 pattern형성에 관한 연구)

  • 김현종;채규호;김태성
    • Electrical & Electronic Materials
    • /
    • v.9 no.1
    • /
    • pp.59-66
    • /
    • 1996
  • Polyimides containing cyclobutane ring in main chain is known to be thermally stable and able to be developed in organic solvents after photolysis with 254 nm UV light. This type of polyimides can be used as promising positive photoresist in VLSI fabrication process. In the current VLSI process, photoresist films are formed by spin coating. The film thickness is more than several hundred nano meters. It seems that there is room for improvement of film coating process by introducing Langmuir Blodgett technique. Thereby ultra thin film photoresist can be formed, and higher density of integration in VLSI be achieved. In the present work, depositing procedure of LB films of this polyimide was investigated. LB film thickness was measured by ellipsometry to evaluate deposited film status. Chemical imidization procedure was studied to avoid several problems in thermal imidization. The pattern of submicron dimension has successfully formed on LB film of 8nm thick, which found showing good contrast.

  • PDF

Influence of Surface Texturing on the Electrical and Optical Properties of Aluminum Doped Zinc Oxide Thin Films

  • Lee, Jaeh-Yeong;Shim, Joong-Pyo;Jung, Hak-Kee
    • Journal of information and communication convergence engineering
    • /
    • v.9 no.4
    • /
    • pp.461-465
    • /
    • 2011
  • An aluminum doped zinc oxide (AZO) film for front contacts of thin film solar cells, in this work, were deposited by r.f. magnetron sputtering, and then etched in diluted hydrochloric acid solution for different times. Effects of surface texturing on the electro-optical properties of AZO films were investigated. Also, to clarify the light trapping of textured AZO film, amorphous silicon thin film solar cells were fabricated on the textured AZO/glass substrate and the performance of solar cells were studied. After texturing, the spectral haze at the visible range of 400 ~750 nm increased substantially with the etching time, without a change in the resistivity. The conversion efficiency of amorphous Si solar cells with textured AZO film as a front electrode was improved by the increase of short-circuit current density ($J_{sc}$), compared to cell with flat AZO films.