• Title/Summary/Keyword: Film temperature

Search Result 6,626, Processing Time 0.035 seconds

Preparation of a PVDF (Polyvinylidene Fluoride) Thin Film Grown by Using the Method of Electric Field Application (전계인가법을 이용한 PVDF 박막의 제작과 특성에 대한 연구)

  • 장동훈;강성준;윤영섭
    • Proceedings of the IEEK Conference
    • /
    • 2000.06b
    • /
    • pp.76-79
    • /
    • 2000
  • The 3$\mu\textrm{m}$-thick PVDF (Polyvinyiidene fluoride) thin film have been prepared using physical vapor deposition with electric field, and its FT-IR specrum, dielectric property and electric conduction phenomenon have been investigated. Since the characteristic peaks ate detected at 509.45 and 1273.6〔cm〕 in the FT-IR spectrum, we are confirmed that the ${\beta}$ -phase is dominant in the PVDF thin film. In the results of dielectric properties, the PVDF thin film shows anomalous dispersion, i.e. gradual decrease of dielectric constant with increase of frequency, and also that the dielectric absorption point changes from 200Hz to 7000Hz with increasing temperature of thin film, which is consistent with the Debye's theory. The activation energy (ΔH) obtained from temperature dependence of dielectric loss is 21.64 ㎉/㏖. We confirm that the electric conduction mechanism of PVDF thin film is dominated by ionic conduction by investigating the dependence of the leakage current of the thin film on the temperature and the electric field.

  • PDF

A Heat Treatment effect on Breakdown of PET Film for EHV Gas VT (EHV Gas VT용 PET Film 절연파괴에 미치는 열처리 영향)

  • Kim, J.D.;Park, J.Y.;Kim, J.D.;Jung, J.G.;Kim, J.S.;Ha, H.J.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2000.05b
    • /
    • pp.212-215
    • /
    • 2000
  • This paper presents the temperature effect of PET Film for insulation EHV Gas VT. We measured the Breakdown Voltage (BDV) and the Partial Discharge Initial Voltage(PDIV) for fresh and heated PET film. In this results, The BDV and PDIV of PET Film was affected by temperature variation and the number of PET Film. The PDIV and BDV of PET Film slightly increased for heating treatment increased as the temperature is increased. however, decreased over about $150^{\circ}C$.

  • PDF

Hydrogen Absorption Characteristics of Al/Pd Film (Al/Pd 박막의 수소 흡수 특성)

  • Cho, Young-Sin
    • Journal of Hydrogen and New Energy
    • /
    • v.17 no.2
    • /
    • pp.234-240
    • /
    • 2006
  • Al film(135.5 nm thick) with Pd film(39.6 nm thick) on the top of it was made by thermal evaporation method. Hydrogen absorption of Al/Pd film was measured by quartz crystal microbalance(QCM) method at room temperature. The sample was activated by hydrogen absorption and desorption cycling at room temperature. Hydrogen was introduced into the film by increasing hydrogen gas pressure step by step up to 640 torr at room temperature. Hydrogen concentration reached up to 25% at $5{\sim}10$ torr. But at high pressure the concentration decreased. This strange tendency was not understood yet. Further study is needed to find out the mechanism of hydrogen absorption in Al in Al/Pd film.

An Experimental Study on the Warpage of a Film Insert Molded Plate (필름 인서트 사출성형 평판의 휨 변형에 관한 실험적 연구)

  • Yoo, Y.G.;Lee, H.S.
    • Transactions of Materials Processing
    • /
    • v.21 no.1
    • /
    • pp.30-35
    • /
    • 2012
  • FIM(Film Insert Molding) is an innovative method of producing decorated parts for a wide range of products. Because it requires fewer steps when compared to conventional production methods, the time and cost of manufacturing high quality components can be reduced considerably. In this paper, the effects of processing conditions on the warpage of film-insert molded plate were investigated by using a design of experiments. The dominant factors affecting warpage were mold temperature and holding pressure. Warpage increased with the temperature difference between stationary mold and fixed one. Even when the mold temperature difference was zero, the plate with a film was bent after ejection such that the film side protruded. As holding pressure increased, warpage decreased significantly. In addition warpage increased with time increment for the film-insert molded plates.

OPERATION OF TILTING 5-PADS proceeding BEARING AT DIFFERENT GEOMETRIC PARAMETERS OF PADS

  • Strzelecki, S.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
    • /
    • 2002.10b
    • /
    • pp.99-100
    • /
    • 2002
  • Radial, tilting-pad proceeding bearings are applied in high speed rotating machines operating at stable small and mean loads and the peripheral speeds of proceeding reaching 150 m/s. The operation of bearing can be determined by static characteristics including the oil film pressure, temperature and viscosity distributions, minimum oil film thickness, load capacity, power loss, oil flow. The operation of 5-lobe tilted-pad proceeding bearing has been introduced at the assumption of adiabatic oil film. The oil film pressure, temperature and viscosity distributions habe received by iterative solution of the Reynolds', energy and viscosity equations. The resulting oil film force, minimum oil film thickness, power loss. oil flow, maximum oil film pressure, maximum temperature were computed for different sets of bearing geometric parameters as: bearing length to diameter ratio, pad angular length and width as well as pad relative clearance.

  • PDF

Heat and mass transfer characteristics in a vertical absorber (수직형 흡수기내 열 및 물질 전달 특성)

  • 서정훈;조금남;최기봉
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.11 no.6
    • /
    • pp.835-845
    • /
    • 1999
  • The objective of the present study was to investigate heat and mass transfer characteristics in a vertical falling film type absorber using LiBr-$H_2O$ solution with 6owt%. The experimental apparatus consisted of an absorber with inner diameter of 17.2 mm and length of 1150mm, a generator, an evaporator/condenser, a solution tank, a sampling trap etc. The parameters were solution temperature of 45 and $50^{\circ}C$, coolant temperature of 30 and $35^{\circ}C$, and film Reynolds numbers from 50 to 150. Pressure drop in the absorber increased as solution and coolant temperatures decreased. Pressure drop in the absorber increased up to the film Reynolds number of 90, and then decreased at the further increase of the Reynolds number above 90. The maximum absorption mass flux observed at the film Reynolds number of 90. Absorption mass flukes increased as coolant temperature decreased. Absorption mass fluxes and heat transfer coefficients under subcooled condition were larger than those under superheated condition. Heat transfer coefficients were affected by solution temperature more than coolant temperature. The maximum absorption effectiveness under the subcooled condition was 23% for coolant temperature of $30^{\circ}C$ and 31% for coolant temperature of $35^{\circ}C$ under the present experimental conditions.

  • PDF

Temperature-Dependent Characteristics of Carbon Nanotubes-Film-Based Electrochemical Sensor (CNT 필름 전기화학 센서의 온도 의존 특성에 관한 연구)

  • Noh, Jaeha;Ahn, Hyung Soo;An, Sangsu;Lee, Changhan;Lee, Sangtae;Lee, Moonjin;Seo, Dongmin;Chang, Jiho
    • Journal of Sensor Science and Technology
    • /
    • v.31 no.3
    • /
    • pp.163-167
    • /
    • 2022
  • In this study, we investigated a carbon nanotube (CNT) film sensor to detect hazardous and noxious substances distributed in seawater. The response change of the sensor was studied according to environmental temperature, and its temperature coefficient of resistance (TCR, α) was measured. The temperature of the CNT film (~50 ㎛) was in the range of 20-50 ℃, and αCNT was calculated to be -0.0011 %/ ℃. We experimentally confirmed that the CNT film had a smaller TCR value than that of the conventional sensor. Therefore, we investigated the response change of the CNT sensor according to temperature. The CNT sensor showed a relatively small error of approximately 2.3 % up to 30 ℃, which is within the temperature range of the seawater of the Korean Peninsula. However, when the temperature exceeded 40 ℃, the error in the CNT sensor increased by more than 5.2 %. We fabricated a metal oxide (ITO, indium-tin-oxide) film and compared its performance with that of the CNT sensor. The ITO sensor showed an error of >12.5 % at 30 ℃, indicating that in terms of the stability of the sensor to temperature, the CNT film sensor has superior performance.

Measurements of Temperature Field and Film-Cooling Effectiveness for a Shower-Head Film Cooling (샤워헤드 막냉각면에서의 온도장 및 막냉각효율 측정)

  • Jeong, Chul-Hee;Lee, Sang-Woo
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.24 no.2
    • /
    • pp.177-187
    • /
    • 2000
  • Measurements of temperature fields and film-cooling effectiveness have been conducted for a shower-head film cooling on the leading edge of a blunt body, which simulates a first-stage turbine stator. In this study, three injection cases are employed for an average blowing ratio based on freestream velocity, M, of 0.5, 1.0 and 1.5. Two (Case 1), four (Case 2) and six (Case 3) rows of normal holes are symmetrically drilled on the three tested circular-cylinder leading edges. The measurements show that regardless of M, the film-cooling effectiveness increases as the injection row is situated at farther downstream location. In Case 1, the film-cooling effectiveness is highest for M = 0.5 and lowest for M = 1.5. On the contrary, in Case 3, the film-cooling effectiveness is highest for M = 1.0 and lowest for M = 0.5. When M = 0.5, the film coverage by the first row of the injection holes deteriorates as the number of the injection row increases. In particular, the film-cooling effectiveness due to the injection through the first row of the holes in Case 3, has a nearly zero value.

Sensitivity of Electroplating Conditions on Young's Modulus of Thin Film (니켈박막의 공정조건에 따른 탄성계수 변화)

  • Kim, Sang-Hyun
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.25 no.8
    • /
    • pp.88-95
    • /
    • 2008
  • Young's modulus of electroplated nickel thin film is systematically investigated using the resonance method of atomic force microscope. Thin layers of nickel to be measured are electroplated onto the surface of an AFM silicon cantilever and Young's modulus of plated nickel film is investigated as a function of process conditions such as the plating temperature and applied current density. It is found that Young's modulus of plated nickel thin film is as high as that of bulk nickel at low plating temperature or low current density, but decreases with increasing plating temperature or current density. The results imply that the plating rate increases as increasing the plating temperature or current density, therefore, slow plating rate produces a dense plating material due to the sufficient time fur nickel ions to form a dense coating.

CMP Properties of Oxide Film with Various Pad Conditioning Temperatures (CMP 패드 컨디셔닝 온도에 따른 산화막의 연마특성)

  • Choi, Gwon-Woo;Kim, Nam-Hoon;Seo, Yong-Jin;Lee, Woo-Sun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.4
    • /
    • pp.297-302
    • /
    • 2005
  • Chemical mechanical polishing(CMP) performances can be optimized by several process parameters such as equipment and consumables (pad, backing film and slurry). Pad properties are important in determining removal rate and planarization ability of a CMP process. It is investigated the performance of oxide CMP process using commercial silica slurry after the pad conditioning temperature was varied. Conditioning process with the high temperature made the slurry be unrestricted to flow and be hold, which made the removal rate of oxide film increase. The pad became softer and flexible as the conditioning temperature increases. Then the softer pad provided the better surface planarity of oxide film without defect.