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Search Results: 1 - 10 of 4155 matches for " Film "
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Hydrodynamics of Liquid Film in Helical Tubes  [PDF]
Mohammed Salah Hameed, Masab Kadhim Jawad
Advances in Chemical Engineering and Science (ACES) , 2012, DOI: 10.4236/aces.2012.21009
Abstract: Hydrodynamic experiments on a liquid film are carried out using water in both straight and helical tubes at angles of inclination ranging between 2.5° and 5° and on three different coil diameters (23.86 cm, 32.74 cm and 41.13 cm) for film Reynolds numbers ranging from 100 to 2000. The film thickness is measured by two micrometers, arranged to measure vertical and horizontal distances within the cross section of the tube. The results of film thickness are related to the hydraulic radius to characterize the film flow in both types of tube. Momentum transfer rates are shown to be higher in helical tubes than in the straight incline tube. An empirical correlation is presented for film thickness in the helical tube in terms of NT (coil tube)/NT (straight tube) for film Dean number ranging from 1 to 1000.
On The Rupture of a Liquid Film Formed on a Droplet Crossing a Horizontal Liquid-Liquid Interface  [PDF]
Jovan Mitrovic
Journal of Encapsulation and Adsorption Sciences (JEAS) , 2012, DOI: 10.4236/jeas.2012.23005
Abstract: A gravity droplet crossing a liquid-liquid interface is covered on the forefront with a film of the leaving liquid phase. The film thickness is not homogeneous over the droplet surface, and it reduces as the droplet penetrates the interface, particularly in the stretched area where it then ruptures. An expression for the film thickness in the stretched region is deduced from a force balance. The film rupture is expected to occur at a droplet position when the normal stress in the stretched film reaches the tensile strength of the liquid. By using some experimental data from literature the expression delivers 26 nm for the film thickness at rupture, while Burrill and Woods [1] obtained experimentally values between 30 nm and 50 nm.
Characterisation of Thin Films Using a Coherence Scanning Interferometry  [PDF]
Yang Yu, Daniel Mansfield
Journal of Materials Science and Chemical Engineering (MSCE) , 2015, DOI: 10.4236/msce.2015.31003
Abstract:

Accurate measurement of film thickness and its uniformity are very important to the performance of many coated surfaces and for many applications are critical. Effective inspection of the film thickness and uniformity is the key to high performance. Conventionally, film thickness is meas- ured using a spectrophotometer/reflectometer, ellipsometer or a physical step measurement; however, these techniques all have limitations. Coherence Scanning Interferometry (CSI) is an established method to measure surface topography as this technique offers many advantages such as speed, ease of use and accuracy. The measurement of “thick” films (exceeding ~1.5 μm) which gives rise to clearly separate fringe bunches is a well-established CSI capability. However, a methodology known as the ‘helical complex field’ (HCF) [1] [2] function allows film thickness to be measured down to ~25 nm. This new method, combined with Coherence Correlation Interferometry (CCI) [3] offers film thickness measurements with sub-nanometre vertical resolution and ~1 μm lateral resolution. It is ideally suited for detailed analysis of coated optical surfaces. In this paper, the fundamentals of the techniques are described and some case studies are presented.

“Le Temps Suspendu”: Suspended Time, Surrealism and Shamanic Myth  [PDF]
Kurt Cline
Advances in Literary Study (ALS) , 2016, DOI: 10.4236/als.2016.42004
Abstract: A close examination of Rene Clair’s films Paris qui Dort and Entr’acte reveals a connection between Clair’s cinematic technique of “instantanéisme” and Breton’s notion of “suspended time”. The Surrealist Voice emerges from the liminal state between sleeping and waking as “spoken thought”, the voice of being revealing itself to the poet. It is poesis speaking itself.
Chris Mathieu & Jesper Strandgaard Pedersen: Dansk film i krydsfeltet mellem samarbejde og konkurrence. Lund: Ariadne F rlag. 2009. Chris Mathieu & Jesper Strandgaard Pedersen (eds.): Dansk film i krydsfeltet mellem samarbejde og konkurrence. Lund: Ariadne F rlag. 2009.
Jakob Isak Nielsen
MedieKultur : Journal of Media and Communication Research , 2010,
Abstract:
Principal Component Analysis of EBT2 Radiochromic Film for Multichannel Film Dosimetry  [PDF]
Richard E. Wendt III
International Journal of Medical Physics,Clinical Engineering and Radiation Oncology (IJMPCERO) , 2014, DOI: 10.4236/ijmpcero.2014.33021
Abstract:

Radiochromic film with a dye incorporated into the radiation sensitive layer [Gafchromic EBT2, Ashland, Inc.] may be digitized by a color transparency scanner, digitally processed, and calibrated so that a digital image in units of radiation absorbed dose is obtained. A transformation from raw scanner values to dose values was developed based upon a principal component analysis of the optical densities of the red, green and blue channels of the color image of a dose of 0.942 Gy delivered by a Sr-90/Y-90 disk-shaped source. In the order of increasing eigenvalue, the three eigenimages of the principal component analysis contained, by visual inspection, 1) mainly noise; 2) mainly a pattern of irregular streaks; and 3) most of the expected dose information along with some of the same background streaking that predominated in the second eigenimage. The combination of the second and third eigenimages that minimized the background streaking was converted into a transformation of the red, green and blue channels optical densities and applied to films with a range of doses from 0 to 63.7 Gy. The curve of dose vs. processed optical density was fit by a two-phase association curve. This processing was applied to a film exposed from its edge by a different Y-90 source in a configuration that was modeled by Monte Carlo simulation. The depth-dose curves of the measurement and simulation agree closely, suggesting that this approach is a valid method of processing EBT2 radiochromic film into maps of radiation absorbed dose.

Investigation of the Effect of Film Thickness and Heat Treatment on the Optical Properties of TeSeSn Thin Films  [PDF]
A. Elwhab B. Alwany, O. M. Samir, Mohammed A. Algradee, M. M. Hafith, M. A. Abdel-Rahim
World Journal of Condensed Matter Physics (WJCMP) , 2015, DOI: 10.4236/wjcmp.2015.53023
Abstract: Glassy substrates TeSeSn thin films were thermally evaporated onto chemically cleaned glass. The as-deposited (as-prepared) and annealed thin films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and optical transmission. The optical absorption of the as-prepared and annealed TeSeSn thin films is studied in the wavelength range of 300 nm - 900 nm. The direct optical energy gap (Eg) increases from 1.989 to 2.143 eV with increasing the thickness of the as-prepared films from 100 to 200 nm. The annealed TeSeSn films showed a decrease in the optical energy gap with increasing the annealing temperature. The effect of heat treatment on the lattice dielectric constant (εL) and carrier concentration (N) are also studied.
A Review of the Aqueous Aerosol Surface Chemistry in the Atmospheric Context  [PDF]
Kalliat T. Valsaraj
Open Journal of Physical Chemistry (OJPC) , 2012, DOI: 10.4236/ojpc.2012.21008
Abstract: In this review the surface chemistry and properties of aqueous atmospheric aerosols are explored. Water plays a major role in scavenging pollutants. Reactions occur on thin water films in atmospheric aerosols. The study of the aerosol wa- ter surface is important to properly account for chemical transformations in the troposphere. The thermodynamics of adsorption of organic molecules and oxidant species on the aqueous surface and, the techniques employed to quantify the adsorption isotherms are summarized. Experimental techniques for elucidating the reactions on the water surface are described. Field and laboratory data for oxidation reactions of compounds at the air-water interface are summarized. The Langmuir-Hinshelwood reaction mechanism is useful in quantifying the reaction rate on the aqueous aerosol sur- face. A hypothesis for the large heterogeneous reaction rate on the water surface over the homogeneous bulk aqueous phase reaction is presented.
Organic Thin Film Transistors Based on Distyryl-Oligothiophenes: Role of AFM Images in Analyses of Charge Transport Properties  [PDF]
Noriyuki Yoshimoto, Hugues Brisset, Jorg Ackermann, Christine Videlot-Ackermann
Open Journal of Applied Sciences (OJAppS) , 2012, DOI: 10.4236/ojapps.2012.24042
Abstract: Significant advances have been made recently in the area of organic electronics and optoelectronics based on small molecules as a result of an improved chemistry and a better technology. Together with light emitting diodes and solar cells, transistors are among the most studied components. The development of new semiconductors induced a real improvement in organic thin film transistor’s performances. Additionally, the synthesis of new soluble and air-stable molecules with the ability to process the active materials at low temperatures over large areas on substrates such as plastic or paper provide unique technologies and generate new applications. However the control of the solid state structure has emerged as essential to realize the full intrinsic potential that organic semiconductors possess. Atomic force microscopy (AFM) was likely to contribute to a further advancement of knowledge. The ability of the AFM to produce three dimensional maps at the micro- and nanometer scale has greatly increased its popularity as an imaging tool. Recently, distyryl-oligothiophenes and their derivatives appear as a new class of molecular semiconductors. Detailed morphological studies of organic active layers based on such new semiconductors involved in organic thin film transistors (OTFTs) have brought a large knowledge about the impact of chemical and physico-chemical aspects on charge transport efficiency.
Optical Microstructure Design Optimization for Display Backlighting  [PDF]
Chi-Chang Hsieh, Yan-Huei Li
Modern Mechanical Engineering (MME) , 2013, DOI: 10.4236/mme.2013.34027
Abstract:

This study proposes an innovative design method for functional optical film microstructures used in displays and applies this design to LCD backlighting to replace multi-layer optical film functional integration with composite optical film. We design a novel optical film microstructure based on light uniformity and wide-angle lumination distribution and determine the optimal optical microstructure parameters by combining the global optimization of a genetic algorithm with ray tracing. The purpose of this study is to develop substitutes for traditional multi-layer prism brightness enhancers and light-diffusing film stacks and to examine the structural changes during calculations and summarize the characteristics. In this study, we focus on determining the optimal light uniformity of new optical film microstructures. The seven-inch LED backlight module of the method proposed in this study achieved 94.59% uniformity and 168° lumination distribution while reducing thickness by 66% to 82% compared to a traditional multi-layer optical film stack.

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