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The history of the scientific research on foam films, traditionally known as soap films, dates back to as early as the late 17th century when Boyle and Hooke paid special attention to the colours of soap bubbles. Their inspiration...
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The history of the scientific research on foam films, traditionally known as soap films, dates back to as early as the late 17th century when Boyle and Hooke paid special attention to the colours of soap bubbles. Their inspiration was transferred to Newton, who began systematic study of the science of foam films. Over the next centuries, a number of scientists dealt with the open questions of the drainage, stability and thickness of foam films. The significant contributions of Plateau and Gibbs in the middle/late 19th century are particularly recognized. After the "colours" method of Newton, Reinold and Rucker as well as Johhonnot developed optical methods for measuring the thickness of the thinner "non-colour" films (first order black) that are still in use today. At the beginning of the 20th century, various aspects of the foam film science were elucidated by the works of Dewar and Perrin and later by Mysels. Undoubtedly, the introduction of the disjoining pressure by Derjaguin and the manifestation of the DLVO theory in describing the film stability are considered as milestones in the theoretical development of foam films. The study of foam films gained momentum with the introduction of the microscopic foam film methodology by Scheludko and Exerowa, which is widely used today. This historical perspective serves as a guide through the chronological development of knowledge on foam films achieved over several centuries. (C) 2015 Elsevier B.V. All rights reserved.
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Experimental data were obtained to reveal the complex dynamics of thin liquid films evaporating on heated horizontal surfaces, including formation and expansion of dry spots that occur after the liquid films decreased below critic...
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Experimental data were obtained to reveal the complex dynamics of thin liquid films evaporating on heated horizontal surfaces, including formation and expansion of dry spots that occur after the liquid films decreased below critical thicknesses. The critical thickness of water film evaporating on various material surfaces is measured in the range of 60-150 μm, increasing with contact angle and heat flux while decreasing with thermal conductivity of the heater material. In the case of hexane evaporating on a titanium surface, the liquid film is found resilient to rupture, but starts oscillating as the averaged film thickness decreases below 15 μm.
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The lubrication characteristics of seal-type thrust bearings with dimples on the lubricating surface were experimentally investigated. Circular and two types of fan-shape dimples were etched on the stationary specimen of the beari...
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The lubrication characteristics of seal-type thrust bearings with dimples on the lubricating surface were experimentally investigated. Circular and two types of fan-shape dimples were etched on the stationary specimen of the bearings. A plane (dimple-free) bearing were also tested for comparisons. In the experiments, the test results obtained by measurements with a fixed fluid film thickness were compared to those by the general measurements with fixed applied load, and their validities were clarified. The fluid film force, frictional torque, and fluid film thickness were measured in both types of test devices. In addition, the lubricating surface were visualized during experiments. As the results, the oil film force of the circular dimple was about three times larger than that of the fan-shaped dimples, and the frictional torque of the circular dimple was also slightly smaller. The measurement results obtained by both types of test devices were in good agreement, including with cavitation phenomena, and the validity of the measurement method with a fixed fluid film thickness was confirmed.
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An experiment was setup to study film width and film thickness of a free falling water film on a large inclined steel plate with no heat transfer. Based on results a semi-empirical correlation was developed to predict the film wid...
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An experiment was setup to study film width and film thickness of a free falling water film on a large inclined steel plate with no heat transfer. Based on results a semi-empirical correlation was developed to predict the film width and film thickness for partially film-covered condition, and the prediction of the film width was in agreement, to within +/- 20%, with the experiment results. And different film thickness correlations were examined with experiment data under fully film-covered condition, and it showed that at lower Reynolds the Nusselt theory predicted the average film thickness well and at higher Reynolds the Lel correlation predicted better. The transition region of Reynolds between these two was related to the measuring location relative to the liquid inlet.
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BaTiO_3 and PZT films were prepared from alkoxide-acetate solutions containing polyvinylpyrrolidone (PVP) by non-repetitive dip-coating. it was demonstrated that PVP incorporated in gel films suppresses crack formation during heat...
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BaTiO_3 and PZT films were prepared from alkoxide-acetate solutions containing polyvinylpyrrolidone (PVP) by non-repetitive dip-coating. it was demonstrated that PVP incorporated in gel films suppresses crack formation during heating and increases the critical thickness, the maximum thickness achievable without crack formation via single-step deposition. Using PVP crack-free BaTiO_3 and PZT films 1.2 and 0.5 #mu#m in thickness could be prepared, respectively, via single-step dip-coating. The films were fairly transparent and dense in microstructure. The tensile stress in heat-treated BaTiO_3 films was also demonstrated to decrease significantly by incorporating PVP in gel films.
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Rescanning film continues to be a cost-effective way to supply library content to audiences via 2K theatrical projection, Blu-ray disc, high definition (HD) cable and now 4K high dynamic range (HDR) streaming. Film remastering has...
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Rescanning film continues to be a cost-effective way to supply library content to audiences via 2K theatrical projection, Blu-ray disc, high definition (HD) cable and now 4K high dynamic range (HDR) streaming. Film remastering has consistently provided improved results over the lasttwo increases in digital resolution, from standard definition (SD) to HD and HD to 4K. Through these transitions, 35mm film has proven to be a reliable source format for solid results. As 8K becomes the next resolution goalpost, this article looks at whether scanning 35mm film at higher than4K resolution continues to bring value. The fluid nature of resolution is explored, highlighting crucial factors from acquisition to display that have an impact on the resolution of any particular shot. The article describes key findings from a 10K film scanning test to identify some of theadvantages and challenges inherent in the next wave of high-resolution film scanning.
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Gallium based liquid metal alloys (GLMAs) have tremendous prospects in diverse applications, such as transient devices, soft robotics, biomedical sensing, and health monitoring, due to being endowed with compelling deformability a...
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Gallium based liquid metal alloys (GLMAs) have tremendous prospects in diverse applications, such as transient devices, soft robotics, biomedical sensing, and health monitoring, due to being endowed with compelling deformability and conductivity simultaneously. Unfortunately, most GLMA-based flexible devices require external power supply, which might cause some potential issues including additional weight, occupied space, and frequent replacement. Alternatively, self-powered concepts, by biologically converting mechanical forces to electric energy, are deemed as a promising strategy. Thus, the challenge that GLMAs are applied to self-powered system is critical and imperative. This study has demonstrated a self-powered and stretchable magnetoelectric film based on GLMAs. The magnetoelectric film is able to conduct mechanoelectrical conversion via controllable distance of electromagnetic interaction during cyclic stretching-releasing process. To investigate the mechanoelectrical conversing mechanism, an equivalent Maxwell's numerical simulation is combined with experimental results, exploring different experimental parameters. Furthermore, diverse programmed patterning of GLMAs and structure designs are utilized to tune electrical performance. It is believed that the magnetic/electrical synergistic design principle will create a new avenue for liquid metals as functional material in the development of wearable electronics with large strains.
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Newton black films correspond to the ultimate stage of thinning of surfactant films and are molecularly assembled. The organization properties of surfactant molecules are widely used for ordering sufficiently small organic or inor...
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Newton black films correspond to the ultimate stage of thinning of surfactant films and are molecularly assembled. The organization properties of surfactant molecules are widely used for ordering sufficiently small organic or inorganic objects. Examples are the Langmuir-Blodgett or the Langmuir-Schaefer methods. The resulting arrangements have a wide range of applications. But, so far, surfactant black films have been studied mainly in their fragile free-standing form. To render such films amenable to practical applications, it is therefore necessary to find ways of transfering them onto a solid substrate. In this paper, we present a method to transfer different surfactant bilayers onto a hydrophobic solid substrate. The transferred films cover a large surface area (a few cm(2)) and X-ray reflectivity and atomic force microscopy prove that the organization of the film is preserved. This method can be applied to many kinds of surfactants. We show here results for a cationic surfactant (hexadecyltrimethylammonium bromide), a non-ionic surfactant (hexaethylene glycol monododecylether), and a fluorinated non-ionic surfactant. Moreover freestanding Newton black films have been proved to organize monolayers of large biological molecules with surfactants such as hexaethylene glycol monododecylether, phospholipids and fluorinated surfactants. Driving forces are either diffusion process or electrostatic forces. Combining the insertion and organization of bio-molecules or nanoparticles within the surfactant bilayers and the transfer of these architectures onto a solid substrate has a great potential for the formation of two- or even three-dimensional architectures of nanosized particle assemblies which have fundamental as well as practical applications.
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Fe-based superconductors bridge a gap between MgB_2 and the cuprate high temperature superconductors as they exhibit multiband character and transition temperatures up to around 55 K. Investigating Fe-based superconductors thus pr...
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Fe-based superconductors bridge a gap between MgB_2 and the cuprate high temperature superconductors as they exhibit multiband character and transition temperatures up to around 55 K. Investigating Fe-based superconductors thus promises answers to fundamental questions concerning the Cooper pairing mechanism, competition between magnetic and superconducting phases, and a wide variety of electronic correlation effects. The question addressed in this review is, however, is this new class of superconductors also a promising candidate for technical applications? Superconducting film-based technologies range from high-current and high-field applications for energy production and storage to sensor development for communication and security issues and have to meet relevant needs of today's society and that of the future. In this review we will highlight and discuss selected key issues for Fe-based superconducting thin film applications. We initially focus our discussion on the understanding of physical properties and actual problems in film fabrication based on a comparison of different observations made in the last few years. Subsequently we address the potential for technological applications according to the current situation.
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