• 제목/요약/키워드: Thickness dependence

검색결과 499건 처리시간 0.033초

식품 안전성 확보를 위한 목재 식기용 에폭시 코팅의 두께 결정 (Determining the Safer Thickness of the Epoxy Coating on Wooden Utensils)

  • 이광수;임동길;김상엽;장미란;김우성;이영자
    • 한국식품영양과학회지
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    • 제33권2호
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    • pp.447-450
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    • 2004
  • 목재에 코팅재로 사용되는 에폭시 수지로부터의 총괄이행량에 대한 모델을 정립하고, 이를 이용하여 안전성확보에 필요한 두께의 정도를 계산하였다. 에폭시 수지를 통한 총괄이행은 위생적 관심영역에서 확산모델에 의하여 해석이 가능하였고, 투과성 겉보기 투과성 지표에 미치는 온도의 영향은 Arrhenius 방정식으로 설명이 가능하였다. 그리고 일반적인 식품공전의 6$0^{\circ}C$, 30분의 용출조건에서 위생적 한도를 만족시키기 위한 최소의 코팅두께는 0.004 mm였다.

Ag의 두께에 따른 비정질 As-Ge-Se-S의 홀로그래픽 특성연구 (Holographic Properties in Amorphous As-Ge-Se-S with Ag Thickness)

  • 김충혁
    • 한국전기전자재료학회논문지
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    • 제25권3호
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    • pp.213-217
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    • 2012
  • In this study, we have investigated the holographic grating formation on Ag-doped amorphous As-Ge-Se-S thin films. The dependence of diffraction efficiency as afunction of Ag layer thickness has been investigated in this amorphous chalcogenide films. Holographic gratings was formed using [P:P] polarized Diode Pumped Solid State laser (DPSS, 532.0 nm). The diffraction efficiency was obtained by +1st order intensity. The results were shown that the diffraction efficiency of Ag/AsGeSeS double layer thin films for the Ag thickness, the maximum grating diffraction efficiency using 60 nm Ag layer is 0.96%.

Study on the Formation of SiOC Films and the Appropriate Annealing Temperature

  • Oh, Teresa
    • Journal of information and communication convergence engineering
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    • 제9권2호
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    • pp.217-219
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    • 2011
  • As silicon devices shrink and their density increases, the low dielectric constant materials instead of $SiO_2$ film is required. SiOC film as low-k films was deposited by the capacitively coupled plasma chemical vapor deposition and then annealed at $300{\sim}500^{\circ}C$ to find out the properties of the dependence on the temperature and polarity. This study researched the dielectric constant using by the structure of the metal/SiOC film/p-Si, chemical shift, thickness, refractive index and hardness. The trend of reflective index was inverse proportioned the thickness, but the dielectric constant was proportioned it. The dielectric constant decreased with decreasing the thickness and the increment of the refractive index.

층류유동 저습도 조건에서의 평행평판형 냉각판 서리성장 실험 (Experiment of frost growth on the parallel plates in the condition of laminar and low humidity)

  • 한흥도;노승탁
    • 설비공학논문집
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    • 제11권4호
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    • pp.440-447
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    • 1999
  • The frosting characteristics on the vertical parallel plates with three cooling plates were experimentally investigated. The experimental parameters were the cooling plate temperature, the air humidity, the air temperature, the air Reynolds number, and the location. The frosting conditions were limited to air temperatures from 10 to $15^{\circ}C$ , air Reynolds numbers from 1600 to 2270, air humidity ratios from 0.00275 to 0.0037kgw/kga and cooling plate temperatures from -10 to $-20^{\circ}C$. Frost growth and density toward the front of the plate were more thick and dense than toward the rear. Frost growth increased with decreasing plate temperature and increasing humidity. In the conditions of the laminar flow, dew point below $0^{\circ}C$and non-cyclic frosting period, frost thickness increased with increasing air temperature. The reason of increasing frost thickness with increasing air temperature was sublimation-ablimation process. The average growth thickness along the locations showed little dependence on the Reynolds numbers.

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Thickness Dependence of the Glass Transition Temperature in Thin Polymer Films

  • Lee, Jeong-Kyu;Zin, Wang-Cheol
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.201-201
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    • 2006
  • In this study the glass transition temperature in thin polymer films has been studied. Ellipsometry has been used to measure $T_{g}$ of thin film as a function of film thickness. Empirical equation has been proposed to fit the measured $T_{g}$ pattern with thickness. Also, a continuous multilayer model was proposed and derived to describe the effect of surface on the observed $T_{g}$ reduction in thin films, and the depth-dependent $T_{g}$ profile was obtained. These results showed that $T_{g}$ at the top surface was much lower than the bulk $T_{g}$ and gradually approached the bulk $T_{g}$ with increasing distance from the edge of the film. The model and equation were modified to apply for the polymer coated on the strongly favorable substrate and the freely standing film.

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Magnetic Properties and Magnetoimpedance Effect in Mumetal Thin Films

  • Cho, Wan-Shik;Yoon, Tae-Sick;Lee, Heebok;Kim, Chong-Oh
    • Journal of Magnetics
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    • 제6권1호
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    • pp.9-12
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    • 2001
  • The dependence of the magnetoimpedance effect (MI) on magnetic properties has been investigated in mumetal thin films prepared by rf magnetron sputtering. Coercivity of thin films prepared at 400 W was about 0.4 Oe, and the magnetic anisotropy field of films deposited under a uniaxial magnetic field decreased with increasing film thickness. The saturation magnetization of mumetal films increased with rising input power and thickness and was smaller than that of permalloy films. Transverse incremental Permeability (TPR) of films of 1$\mu m$ thick increased with increasing effective permeability. The magneto impedance ratio (MIR) was proportional to TPR in films 1$\mu m$ thick but in spite of lower effective permeability at higher thicknesses, MIR increased due to skin effect. The height of the double peaks in the MIR curves decreased with decreasing anisotropy and thickness. The maximum MIR value for a 4$\mu m$ thick 75% at 36.5 MHz.

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Sol-Gel 공정으로 Plastic표면에 Glass박막 제조에 관한 연구 (Preparation of Glass Thin Film onto Plastic Surface by Sol-Gel Process)

  • 양천회
    • 한국안전학회지
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    • 제13권1호
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    • pp.85-91
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    • 1998
  • Sol-gel derived silica films were prepared by dip-coating onto polymethylmethacylate with Tetraethoxysilane(TEOS) as starting materials. Film properties such as viscosity and thickness were investigated as a function of dip speed, waterprecursor ratio, sol aging time. IR spectra of the gel films prepared from TEOS at various R are given. At small values of R the absorption peaks assignable to C-H vibration in $-OC_2H_5$ groups are observed around 3000 and 1500-1300 $cm^{-1}$. These bands indicate that the -$-OC_2H_5$ groups are retained in the gel at small values of R because of incomplete hydrolysis of TEOS. Film behaviour was interpreted in terms of the dependence of hydrolysis and condensation rates on the interplay between sol pH and waterprecursor ratio. Film thickness was found to increase by approximately a factor of two as waterprecursor ratio increased from two to six. Film thickness also increased with sol prepolymerization time. Surface quality was correlated with processing conditions.

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Current Density Equations Representing the Transition between the Injection- and Bulk-limited Currents for Organic Semiconductors

  • Lee, Sang-Gun;Hattori, Reiji
    • Journal of Information Display
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    • 제10권4호
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    • pp.143-148
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    • 2009
  • The theoretical current density equations for organic semiconductors was derived according to the internal carrier emission equation based on the diffusion model at the Schottky barrier contact and the mobility equation based on the field dependence model, the so-called "Poole-Frenkel mobility model." The electric field becomes constant because of the absence of a space charge effect in the case of a higher injection barrier height and a lower sample thickness, but there is distribution in the electric field because of the space charge effect in the case of a lower injection barrier height and a higher sample thickness. The transition between the injection- and bulk-limited currents was presented according to the Schottky barrier height and the sample thickness change.

Pt Thickness Dependence of Oscillatory Interlayer Exchange Coupling in [CoFe/Pt/CoFe]/IrMn Multilayers with Perpendicular Anisotropy

  • Lee, Sang-Suk;Choi, Jong-Gu;Kim, Sun-Wook;Hwang, Do-Guwn;Rhee, Jang-Roh
    • Journal of Magnetics
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    • 제10권2호
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    • pp.44-47
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    • 2005
  • The oscillatory interlayer exchange coupling (IEC) has been shown in pinned $[CoFe/Pt(t_{pt})/CoFe]/IrMn$ multi-layers with perpendicular anisotropy. The period of oscillation corresponds to about 2 monolayers of Pt. The oscillatory behavior of IEC depending on the nonmagnetic metallic Pt thickness is thought to be related the antiferromagnetic ordering induced by IrMn layer. Oscillatory IEC as function of insulating NiO thickness has been observed in $[Pt/CoFe]_4/NiO(t_{NiO})/[CoFe/Pt]_4$ multilayers. The effect of N (number of bilayer repeats) upon the magnetic property of [Pt/CoFe]N/IrMn is also studied.

Epoxy/MICA 복합체의 MICA 충진함량 변화에 대한 기계적, 전기적 특성연구 (A Study on Mechanical, Electrical Properties of Epoxy/MICA Composites with MICA Filled Contents)

  • 박재준
    • 전기학회논문지
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    • 제62권2호
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    • pp.219-227
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    • 2013
  • This paper reported a study on the thermal, mechanical and electrical insulation properties of epoxy/mica composites. To investigate the effect of mica content, glass transition temperature, mechanical properties such as tensile and flexural strength, and insulation breakdown properties for epoxy composites with various contents of mica. The effect of insulation thickness on insulation breakdown property was also studied. It was observed that tensile and flexural strength decreased with increasing mica content, while elastic modulus increased as the mica content increased. AC insulation breakdown strength for all epoxy/mica composites was higher than that of neat epoxy and that of the system with 20 wt% mica was 14.4% improved. As was expected, insulation breakdown strength at $30^{\circ}C$ was far higher than that at $130^{\circ}C$, and it was also found that insulation breakdown strength was inversely proportion to insulation thickness.