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Dissertations / Theses on the topic 'Film thickness'
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1
Wang, Dong. "Fatigue behavior of thin Cu films film thickness and interface effects /." Karlsruhe : Forschungszentrum Karlsruhe, 2007. http://d-nb.info/98578797X/34.
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Duszynski, Marek. "Measurement of lubricant film thickness in reciprocating engines." Thesis, Imperial College London, 1999. http://hdl.handle.net/10044/1/8268.
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Makihara, Hiroshi. "Water film thickness in the clay-water system." Diss., The University of Arizona, 1999. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu_e9791_1999_20_sip1_w.pdf&type=application/pdf.
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Binnington, P. G. "The measurement of rotary shaft seal film thickness." Thesis, Durham University, 1991. http://etheses.dur.ac.uk/1121/.
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Wang, Dong. "Binder Film Thickness Effect on Aggregate Contact Behavior." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/34510.
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This study presents a study on the binder film thickness effect on aggregate contact behavior. As a three-phase material composed of aggregates, asphalt binder and air voids, asphalt mixture could be considered as a visco-elastic material in the low stress level. Since the behavior of the mixture depends largely on the relationship of different components, a well developed contact model for micro-structural modeling is very important for understanding the deformation mechanism of the mixture. In this study, the contact modeling of asphalt mixture was reviewed and the numerical tools used to investigate the micromechanical behavior of asphalt mixture will also be introduced. By using the cabinet x-ray tomography system, the displacement and resistant force of a system of particles bonded by a thin layer binder are measured and recorded. Then, the results are compared with the theoretical solutions of a normal compliance model for a system comprised of two elastic particles bonded by a thin layer of visco-elastic binder. A closed-form time-dependent relationship between the contact forces and the relative particle/binder movements was developed. A reasonable agreement between experiments results and model predicted results is obtained combined with parametric analysis.Master of Science
6
Sauter, Linda Xenia. "Microstructural and film thickness effects on the thermomechanical behavior of thin Au films." Stuttgart : Max-Planck-Inst. für Metallforschung, 2007. http://d-nb.info/995370753/34.
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Wang, Dong [Verfasser]. "Fatigue behavior of thin Cu films : film thickness and interface effects / Dong Wang." Karlsruhe : Forschungszentrum Karlsruhe, 2007. http://d-nb.info/98578797X/34.
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Sauter, Linda Xenia. "Microstructural and film thickness effects on the thermomechanical behavior of thin Au films." [S.l. : s.n.], 2006. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-31632.
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Deutsch, Eric J. (Eric Joseph). "Piston ring friction analysis from oil film thickness measurements." Thesis, Massachusetts Institute of Technology, 1994. http://hdl.handle.net/1721.1/36435.
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Lord, John. "Film thickness measurements for the characterization of EHL contacts." Licentiate thesis, Luleå, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-16934.
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This licentiate thesis describes experimental techniques related to the investigation of elastohydrodynamic lubrication of point contacts as well as measurements and evaluation of results from laboratory tests. Elastohydrodynamic lubrication is one of the most severe forms of lubrication when a medium (often a liquid) is expected to separate two surfaces in a mechanical device under extremely high pressures and shear strain rates as well as with very thin lubricant films. These criteria set high demands on both the surfaces themselves and the lubricant. In order to simulate elastohydrodynamic lubrication, a ball and disc apparatus, of which there are many different types and configurations, can be used. These produce images (interferograms) of the actual conjunction by employing the phenomena of optical interference. In the work presented in this thesis, a computer controlled ball and disc apparatus has been used to investigate two different types of interferogram evaluation methods; the HSI and the Multi Channel method. Lubricant behaviour at low rolling speeds and hence very thin lubricating films, was also studied. It was seen that some lubricants create very thin boundary layers preventing direct contact between the ball and disc. It was also concluded that the measurement of very thin lubricant films requires interferogram evaluation methods which do not depend upon model based calibrations. At high slide/roll ratios, and often with lubricants possessing a high pressure-viscosity coefficient, dimples may form within the normally flat central contact region. The cause of this phenomena has been disputed, but studies suggest that differences in the thermal properties of the contacting bodies may be the cause. Experiments which caused such dimples were used as the basis for evaluating the hybrid film thickness evaluation scheme which takes account of the influence of pressure on the lubricant's refractive index. This proved useful since dimple formation causes abnormally high pressures which would, with other techniques, reduce the accuracy of the film thickness measurements. The shear rates which occur in a sliding contact affects the rheological and thermal properties of the lubricant within the conjunction. This results in a reduction in film thickness from that predicted by isothermal assumptions. It was shown that this reduction is not only affected by operating conditions, but is also lubricant type dependent. Experiments indicated that an ester base fluid possessed characteristics which gave less film thickness reduction as compared to a mineral and a Poly-a-olefin base fluid.Godkänd; 2001; 20070314 (ysko)
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Ostovar, Pendar. "Fluid aspects of piston-ring lubrication." Thesis, Imperial College London, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324316.
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Jablonka, Karolina. "Study of film thickness in elastohydrodynamic contacts by electrical capacitance." Thesis, University of Sussex, 2015. http://sro.sussex.ac.uk/id/eprint/56839/.
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The current work, sponsored by the SKF Engineering and Research Centre in the Netherlands, is focused on studying aspects of lubrication relevant to rolling element bearings using electrical capacitance. This includes comparative film thickness measurements in glass-on-steel and steel-on-steel contacts, interaction of polar components with surfaces, as well as grease lubrication. It has been proven that the capacitive method can be successfully applied to very thin films, even down to around 10 nm thickness. The main part of the experimental work has been conducted on a test rig that simulates a contact between a ball and a raceway in a ball bearing. In this apparatus an EHD contact is formed between a steel ball and either a glass, or steel disc. For the first time it has been possible to perform parallel measurements of film thickness with an optical method, and electrical capacitance of an EHD contact, which allowed establishing an alternative approach to extracting quantitative film thickness values from the measured capacitance. This procedure has been further applied to a modified rolling element bearing in which all but one of the steel balls were replaced with non-conductive ceramic balls. By simplifying the experimental setup and focusing on a contact between a single ball and raceways it was possible to eliminate some of the system variables, such as unloaded region capacitance, thus giving a much clearer picture of the film thickness in a rolling bearing. The current study shows a high potential of the method giving further insight into the behaviour of lubricants in high-pressure contacts. The information obtained from measured capacitance can be treated as complementary to the output of other available techniques (optical interferometry, surface force apparatus, resistance, and ultrasound) providing a better understanding of the phenomena observed.
13
Harper, Phil. "Measurement of film thickness in lubricated components using ultrasonic reflection." Thesis, University of Sheffield, 2008. http://etheses.whiterose.ac.uk/14930/.
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Many everyday objects are used without consideration of the fact that they rely on a tiny layer of lubricant as thin as 1/1000th of the thickness of a human hair in order to operate correctly. However, without the lubricant, problems are quickly noticed: door hinges squeaking, wear in engines or failure of hip implants. This thesis documents the application of ultrasound to the measurement of this layer of lubricant.
14
Baird, E. M. "The application of Raman spectroscopy to studies of elastohydrodynamic contacts." Thesis, University of Newcastle Upon Tyne, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381942.
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Canli, Sedat. "Thickness Analysis Of Thin Films By Energy Dispersive X-ray Spectroscopy." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612822/index.pdf.
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EDS is a tool for quantitative and qualitative analysis of the materials. In electron microscopy, the energy of the electrons determines the depth of the region where the X-rays come from. By varying the energy of the electrons, the depth of the region where the X-rays come from can be changed. If a thin film is used as a specimen, different quantitative ratios of the elements for different electron energies can be obtained. Unique thickness of a specific film on a specific substrate gives unique energy-ratio diagram so the thickness of a thin film can be calculated by analyzing the fingerprints of the energy-ratio diagram of the EDS data obtained from the film.
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Fung, Wai-sin Wilson, and 馮懷善. "Role of water film thickness in rheology of mortar and concrete." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45150084.
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Hur, Sung-ho. "Model based cross-directional monitoring and control of plastic film thickness." Thesis, University of Strathclyde, 2010. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=25796.
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The main topics of this research are modelling, fault monitoring, and cross-directional control of a plastic film manufacturing process operated by DuPont Teijin Films Ltd. The developed model is of high dimension and built using the first-principles of chemical and mechanical engineering, such as equations for mass transfer, heat transfer, and the flow of viscous fluids in addition to empirical knowledge related to the behaviour of polymer. The model in turn provides a safe off-line platform for developing new cross-directional control and fault monitoring systems. As with other sheet-forming processes, such as papermaking and steel rolling, the plastic film manufacturing process employs large arrays of actuators spread across a continuously moving sheet to control the cross-directional profiles of key product properties. In plastic manufacturing, the main control property is finished product thickness profile as measured by a scanning gauge downstream from the actuators. The role of the cross-directional control system is to maintain the measured cross-directional profiles of plastic properties on target. The second part of this research develops a novel cross-directional controller, which is in turn demonstrated by application to the first-principles model. Fault monitoring systems can be broadly classified into 3 categories: model-based, data-driven, and knowledge-based. The third part of this research introduces a novel model-based fault monitoring system. The system is demonstrated by application to both the first-principles model and industrial data extracted from the real-life plant.
18
Singh, Lovejeet. "The influence of film thickness and molecular weight on the thermal properties of ultrathin polymer films." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/11043.
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Parihar, U., N. Padha, J. R. Ray, M. S. Desai, C. J. Panchal, P. K. Mehta, Ірина Володимирівна Чешко, et al. "Effect of Film Thickness and Annealing on the Structural and Optical Properties of CuInAlSe2 Thin Films." Thesis, Sumy State University, 2013. http://essuir.sumdu.edu.ua/handle/123456789/35321.
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CuIn1 – xAlxSe2 (CIAS) thin films were grown using flash evaporation method by varying the film
thickness from 500 nm to 700 nm. Prepared CIAS thin films were annealed at 573 K for one hour in
vacuum. The influence of film’s thickness and the annealing temperature were characterized by the X-ray
diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive analysis of X-ray (EDAX),
Optical transmission measurements, and Hall Effect measurement. As the film thickness increases the
crystallinity improves and due to that the optical absorption also improves. The further improvement for
different thicknesses of CIAS thin films were observed by annealing. The thicker (700 nm) and annealed
CIAS thin film shows the crystallite size of 24.3 nm, energy band gap of 1.19 eV, and resistivity of about
9 102 Ω cm.
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20
Ali, Fadi. "Effect of Surface Texturing on Friction and Film Thickness under Starved Lubrication Conditions." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-234247.
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Tato disertační práce se zabývá vlivem mělkých mikro-textur na tření a tloušťku filmu v mazaných nekonformních kontaktech za extrémních podmínek a za podmínek hladovění kontaktu. Měření byla realizována na tribometru v konfiguraci ball-on-disk. Kontakt byl pozorován pomocí vysokorychlostní kamery. Pro stanovení součinitele tření byl využit snímač krouticího momentu. V této studii byly popsány dva typy mikrotextur – mikrovtisky a příčné mikrodrážky. Výsledky naznačují, že za podmínek hladovění vedou mikrovtisky ke snížení tření a to díky nárůstu tloušťky mazacího filmu. Mechanismus doplňování mikrovtisků čerstvým mazivem je pravděpodobně způsoben kapilárními jevy ve vstupní oblasti. Třecí plochy s příčnými mikrodrážkami, jejichž délka byla menší než průměr Hertzova kontaktu, potom obecně vykazovaly lepší tribologické parametry ve srovnání s hladkými povrchy. Příčné mikrodrážky vedly k výraznému nárůstu tloušťky mazacího filmu za podmínek hladovění i za extrémních provozních podmínek (protisměrný pohyb). Numerické simulace přechodových jevů příčných mikrodrážek ukázaly dobrou shodu s experimentálními výsledky.
21
Brown, Michal A. Rosakis Ares J. "Measuring stress in thin film-substrate systems featuring spatial nonuniformities of film thickness and/or misfit strain /." Diss., Pasadena, Calif. : Caltech, 2007. http://resolver.caltech.edu/CaltechETD:etd-06042007-171342.
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Woods, William Paul. "The hydrodynamics of thin liquid films flowing over a rotating disc." Thesis, University of Newcastle Upon Tyne, 1995. http://hdl.handle.net/10443/295.
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This study is concerned with flow and stability of thin liquid films flowing over the surface of a disc rotating about a vertical axis. The work consists of a theoretical and experimental investigation into the flow of the steady-state film, and the waves which occur on it. The theoretical model is investigated in its steady-state form (no waves present) using both asymptotic and numerical techniques. The unsteady problem is also examined, using asymptotic methods, for the inception and propagation of waves of small amplitude with respect to the mean film thickness. The experimental investigation employs a light absorption technique to obtain accurate film thickness measurements across individual three dimensional wave profiles. The results are used to test the validity of the small amplitude assumption of the theoretical model, which is found to be restrictive, and to give both qualitative and quantitative data about the large amplitude waves that are often observed.
23
Osman, Saad AbuBakr. "The role of adhesive resin luting agents in crown retention." Thesis, University of Newcastle Upon Tyne, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311998.
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Pethe, Shirish A. "Optimization of process parameters for reduced thickness CIGSeS thin film solar cells." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4623.
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With the advent of the 21st century, one of the serious problems facing mankind is harmful effects of global warming. Add to that the ever increasing cost of fuel and the importance of development of clean energy resources as alternative to fossil fuel has becomes one of the prime and pressing challenges for modern science and technology in the 21st century. Recent studies have shown that energy related sources account for 50% of the total emission of carbon dioxide in the atmosphere. All research activities are focused on developing various technologies that are capable of converting sunlight into electricity with high efficiency and can be produced using a cost-effective process. One of such technologies is the CuIn[sub1-x]Ga[subx]Se[sub2] (CIGS) and its alloys that can be produced using cost-effective techniques and also exhibit high photo-conversion efficiency. The work presented here discusses some of the fundamental issues related to high volume production of CIGS thin film solar cells. Three principal issues that have been addressed in this work are effect of reduction in absorber thickness on device performance, micrononuniformity involved with amount of sodium and its effect on device performance and lastly the effect of working distance on the properties of molybdenum back contact. An effort has been made to understand the effect of absorber thickness on PV parameters and optimize the process parameters accordingly. Very thin (<1 [micro]m) absorber film were prepared by selenization using metallorganic selenium source in a conventional furnace and by RTP using Se vapor. Sulfurization was carried out using H2S gas. Devices with efficiencies reaching 9% were prepared for very thin (<1 [micro]m) CIGS and CIGSeS thin films. It was shown through this work that the absorber thickness reduction of 64% results in the efficiency drop of only 32%. With further optimization of the reaction process of the absorber layer as well as the other layers higher efficiencies can be achieved. The effect of sodium on the device performance is experimentally verified in this work. To the best of our knowledge the detrimental effect of excess sodium has been verified by experimental data and effort has been made to correlate the variation in PV parameter to theoretical models of effect of sodium. It has been a regular practice to deposit thin barrier layer prior to molybdenum deposition to reduce the micrononuniformities caused due to nonuniform out diffusion of sodium from the soda lime glass. However, it was proven in this work that an optimally thick barrier layer is necessary to reduce the out diffusion of sodium to negligible quantities and thus reduce the micrononuniformities. Molybdenum back contact deposition is a bottleneck in high volume manufacturing due to the current state of art where multi layer molybdenum film needs to be deposited to achieve the required properties. In order to understand and solve this problem experiments were carried out. The effect of working distance (distance between the target and the substrate) on film properties was studied and is presented in this work. During the course of this work efforts were taken to carry out a systematic and detailed study of some of the fundamental issues related to CIGS technology and particular for high volume manufacturing of CIGS PV modules and lay a good foundation for further improvement of PV performance of CIGS thin film solar cells prepared by the two step process of selenization and sulfurization of sputtered metallic precursors.ID: 030423396; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (Ph.D.)--University of Central Florida, 2010.; Includes bibliographical references (p. 108-116).
Ph.D.
Doctorate
Department of Electrical Engineering and Computer Science
Engineering and Computer Science
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Cherkassky, Alexander (Alexander Peter) 1963. "Metrology of thin silicon expitaxial films : determination of epitaxial film thickness by Fourier-transform infra-red spectrometry." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/17405.
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Sauter, Linda Xenia [Verfasser]. "Microstructural and film thickness effects on the thermomechanical behavior of thin Au films / vorgelegt von Linda Xenia Sauter." Stuttgart : Max-Planck-Inst. für Metallforschung, 2007. http://d-nb.info/995370753/34.
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Clark, Andrew Chapman. "Dynamic measurements of lubrication film thickness of UHMWPE contacts for total joint replacements." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1181667482/.
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Thesis (Ph.D.) -- Clemson University, 2007.Title from first page of PDF file. Document formatted into pages; contains xviii, 192 p. ; also includes graphics (chiefly col.). Contains additional supplemental files.
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Holt, Vivianne. "Laser induced fluorescence measurement of the tear film thickness under a contact lens." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43429.
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Bryla, Ryan Joseph. "The use of laser induced fluorescence for measurement of engine oil film thickness." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/10586.
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Parkanyi, Tamas. "Rubber friction on ice : investigation of frictional heating and melt water film thickness." Thesis, University of Edinburgh, 2016. http://hdl.handle.net/1842/18751.
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Friction on ice is important for many different fields such as winter sports and vehicle traction. In vehicle handling, maximising the friction coefficient between tyres and the ice surface is key to safety. The friction coefficient between tyre rubber and ice has been observed to be as high as unity at low temperatures and as little as 0.05 close to the ice melting temperature. The observed low friction is due to thin water films generated through frictional heating. Little is known about the formation and behaviour of this fluid film and its thickness has been difficult to measure. Previous attempts included techniques such as capacitance, conductivity and fluorescence spectroscopy, however results have been inconsistent. The primary aim of this study was to develop a measurement technique for this lubricating layer, establishing its thickness and the conditions under which its presence results in low friction. This was done by designing a micro-scale linear tribometer (microtribometer) to measure the friction coefficient (μ) on ice under a microscope. Clear ice, and ice with fluorescent particles of various sizes were created. The two ice types were then joined and tested on. During a friction test on the microtribometer, the particles displaced in the direction of sliding due to melt water presence. Images of the ice surface were taken before and after a friction measurement was made, and the amount of particle movement was assessed. The size and displacement of particles were correlated to the range of melt water thickness for a given sliding condition. This study is the first direct measurement method for the melt water layer on ice. Frictional heating is generated through the physical contact of rubber and ice asperities. By conducting friction measurements with rubbers of varying shear modulus (G*) and surface roughness (Ra) on both the microtribometer and on our large–scale tribometer, FRIMA, analysis of the contact can be made over a range of length scales. Further insight into the interfacial effects was provided by surface roughness measurements of both ice and rubber before and ice after microtribometer tests and in FRIMA. Finally, the use of differential interference contrast in reflected light microscopy with ice friction measurements provided visual evidence of the melt water presence. It was found that the melt water thickness based on particle displacement was between 0.1 to 2μm, for a velocity of 4.3 ⇥ 10−4 ms−1 and 0.5MPa nominal load, between –6°C to 0°C. A decreasing film thickness was found with decreasing temperature and the friction coefficient increased with decreasing temperature. At higher temperatures, the differences between the rubbers on both FRIMA and the microtribometer were found to be negligible because of the lubricating layer. Increasing the rubber surface roughness was found to increase at high and decrease friction significantly at low temperatures. These phenomena can be explained by the decreasing amount of solid-solid contact. A simple analytical approach to interpret the results suggests that the rubber compresses significantly and the surface roughness is smoothened upon contact with ice. Furthermore, simple hydrodynamic shear calculations show that pure liquid shear is insufficient to account for the measured low μ values close to melting temperatures. The combined effect of the increasing melt water presence reducing the real contact area and the significant deformation of the rubber asperities failing to compensate for this reduced contact area can account for the results. It is anticipated that these results provide direction for finding ways to improve solid-solid contact between rubber and ice, as there is some viscoelastic dissipation even at conditions close to the melting temperature. Some topics for example are: improving the thermal conductivity of tyre compounds or further investigating the surface roughness of rubber and ice separately and with the thin liquid film in between.
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Gasni, Dedison. "Ultrasonic reflection for measurement of oil film thickness and contact between dissimilar materials." Thesis, University of Sheffield, 2012. http://etheses.whiterose.ac.uk/2577/.
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The contact between dissimilar materials occurs in many machine elements where one of the contacting parts is manufactured from low modulus materials such as lip seals, o-rings, and metal on polymer prosthetic hip joints. Contacts of this sort of are often operated in the iso-viscous elastohydrodynamic lubrication (I-EHL) regime. Typically, they have been studied using a numerical approach due to lack of sensor of instrumentation for measuring oil film thickness. By developing the technology of sensors such as electromagnetic radiation and magnetic resistance techniques, the phenomenon of lubrication in I-EHL regime has shown results which are better understood. However, the experimental study that has been conducted to date is only appropriate for laboratory-based measurements. This thesis deals with the ultrasonic reflection methods to measure an oil film thickness and contact between dissimilar materials where these methods could be applied in-situ. This warrants special attention because there are two drawbacks of measuring of oil film thickness and contact by using bulk longitudinal wave between dissimilar materials (such as rubber and steel) which have mismatched acoustic impedance. One is the attenuation. The ultrasonic signal will be reduced when passed through the rubber. The other is accessibility. The wave must pass normally through the interface and so the transducer must be mounted on the rubber itself. There are two methods that can be used to measure oil film thickness using ultrasonic reflection: amplitude and phase shift. The amplitude method has been proved successfully for measuring oil film thickness between two similar materials and between two materials with little difference in acoustic impedance, but it fails for contact between two acoustically dissimilar materials. In this case, the phase shift method has the potential to measure oil film thickness. The results show that this method is valid for measuring thin films (h < 40 μm) for contact between Perspex and steel. The application of ultrasonic reflection techniques to measure the lubricant film thickness in iso-viscous elastohydrodynamic lubrication regime has been investigated. The reflection of ultrasonic pulses from the interface between the nitrile sphere and Perspex disk was recorded for a range of lubricated, dry, static, and dynamic contact conditions. In this way, profiles of oil film thickness were created for various loads and sliding speeds. The phenomenon of a wedge-shaped constriction in lubricant film was observed, especially at low speeds. It was also possible to observe cavitation effects on the signal in the exit region. The measured central film thickness results are compared with published models of the lubrication mechanism and experimental data obtained from optical methods. The result shows that the oil film thickness was measured in the region of 1 to 6 µm. The data was shown to be consistent with previous published experimental work using optical methods but somewhat lower than theoretical solutions. Ultrasonic surface waves that are commercially used for non-destructive evaluation (NDE) and damage detection have been also developed to measure contact between soft and hard materials. The measurements were made by using variable and fixed wedge transducers. The reflection coefficient of Rayleigh waves at point and line contacts was measured to study the characteristic of compliant contacts in dry and lubricated conditions. The results show that the increased load causes a decreased reflection coefficient. Therefore, the reflection coefficient of Rayleigh wave at interface between soft and hard materials can be developed as a sensor for o-ring and lip seals and this sensor could be positioned remotely from the contact.
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Kuo, Ming-Tsun. "Field emission and annealing studies of n-type doped hydrogenated amorphous carbon films." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340300.
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Larsen, Crilles Casper. "Process control and evaluation of aqueous latex film coating of pellets in fluidised bed /." Cph. : The Danish University of Pharmaceutical Sciences, department of Pharmaceutics, 2004. http://www.dfh.dk/phd/defences/crillescasperlarsen.htm.
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Іващенко, Максим Миколайович, Максим Николаевич Иващенко, Maksym Mykolaiovych Ivashchenko, Олександр Дмитрович Погребняк, Александр Дмитриевич Погребняк, Oleksandr Dmytrovych Pohrebniak, S. N. Abdulla, and A. A. K. Muhammed. "Design and Fabrication Heterojunction Solarcell of Si-CdS-ZnO Thin Film." Thesis, Sumy State University, 2012. http://essuir.sumdu.edu.ua/handle/123456789/35487.
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Cadmium sulphide (CdS) is a prominent candidate to be used a buffer layer in Si based solar cell. In
this study, absorber layer parameters thickness have been investigated by (SCAPS) to find out the higher
conversion. Moreover, it is found that Jsc,Voc, η is increased for the absorber layer thickness of 500-600 nm
and quantum efficiency is nearly overlap after the 600 nm thickness of the Si absorber layer. In addition, it
is revealed that the highest efficiency cell can be achieved with the absorber layer thickness of 600 nm.
From the simulation results, numerous influences of absorber layer are investigated in Si/CdS/ZnO solar
cell which can lead to the fabrication of high efficiency devices. Experimentally the designed cell fabricated
and the electrical properties measured also Jsc ,Voc ( with lower values) as Si thickness increased until
600 nm. And best efficiency value calculated was 8.9%.
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35
Meziane, Bilel. "Film thickness build-up in highly loaded lubricated contacts under Zero Entrainment Velocity condition." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI005.
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Les contacts lubrifiés sous forte charge sont souvent étudiés dans des conditions de roulement/glissement. Dans ces cas, l’entrainement du lubrifiant dans un coin d’huile explique la présence d’un film séparateur. Cependant, il existe un certain nombre d’applications dans lesquelles les surfaces en contact ont des vitesses égales et opposées. Cela correspond à une vitesse d’entrainement (définie comme la moyenne des vitesses des deux surfaces) nulle. Dans ce cas, les modèles prédictifs de la littérature ne peuvent plus s’appliquer. Dans ce mémoire de thèse, les phénomènes physiques conduisant à une génération de film séparateur à vitesse d’entrainement nulle sont étudiés. Un modèle éléments finis prenant en compte les aspects thermiques et transitoires est mis en œuvre pour mesurer les quantités locales. En régime stationnaire, les résultats numériques sont comparés avec un très bon accord à un jeu de données issu d’une campagne d’expérimentations dédiée. Cette approche duale permet de quantifier l’influence de la charge, de la vitesse des surfaces et de la température externe sur l’épaisseur de film à vitesse d’entrainement nulle. Les contacts sont ensuite étudiés sous une charge variable, ce qui montre l’influence relative des phénomènes thermiques et transitoires pouvant générer une épaisseur de film. En fonction du ratio entre le temps caractéristique de chargement et le temps caractéristique d’échauffement, ces effets peuvent montrer une synergie bénéfique pour le contactHighly loaded lubricated contacts are often studied in rolling/sliding conditions. In those cases, the entrainment of lubricant in a so-called “oil wedge” explains the existence of a separating film thickness. However, in a number of industrial applications, the contact is subjected to opposite surface velocities. In such cases, there is a Zero Entrainment Velocity (defined as the average velocity of the two surfaces) of the fluid. The film thickness prediction formulae developed in the literature for rolling contacts are unusable. In this thesis, the physical phenomena leading to a film build-up under Zero Entrainment Velocity condition are elucidated. A finite element model is used in order to facilitate in-situ measurements. It aims to describe the behaviour of the contact in thermal and transient conditions. In the stationary regime, the numerical values are compared with a very good agreement to a set of results obtained via a tailored experimental campaign. This dual approach enables a quantitative description of the influence of the contact load, surface velocities and external temperature on the film thickness under ZEV condition. Then, the relative influence of the thermal and squeeze effects is studied. Depending on the ratio between the characteristic loading time and the characteristic thermal time, these two effects can show a beneficial synergy for the contact
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Beck, Catherine Keel. "Characterization of Spin Coated Polymers in Nano-environments as a Function of Film Thickness." Thesis, Virginia Tech, 2001. http://hdl.handle.net/10919/34548.
Full textAbstract:
Polymer applications have become more demanding as industry continuously
turns to more microscopic parts. Due to the interactions of the polymer chains with the
supporting surface and the air interface, the thinner films required for such applications
have distinctly different properties than those of the well-defined bulk systems. The goal
of the current research is to elucidate the behavior of ultrathin films. Two separate
studies were performed on thin films supported on silicon wafer substrates: the first
focuses on the viscoelastic cooperativity of thin films, and the second concentrates on the
morphological behavior of polymer brush films.
For the first study, polymethyl methacrylate films were spin coated onto silicon
wafers, and the film thickness was determined using ellipsometry. A series of thin films
were examined using techniques such as dielectric analysis and thermal mechanical
analysis. The theory of cooperativity, which explains polymeric behavior using the
intermolecular and intramolecular forces among polymer chains, was employed to
understand the behavior of these thin films.
Another type of thin film, a polymer brush, was investigated in the second study.
Polymer brushes are formed by chemically bonding one end of many polymer chains to a
substrate. The other ends of the chains can interact with the surrounding environment
creating a brush-like structure. Constraining one end of a polymer chain alters the
behavior of such a thin film. Polymer brushes of the di-block copolymer poly(t-butyl
methacrylate) and polystyrene were produced on silicon wafers using spin coating
techniques. The effects of both grafting density and solvent washes were analyzed using
contact angle analysis and atomic force microscopy. In addition, hydrolysis was
successfully performed on existing polymer brush samples to produce polymer brushes of
the di-block copolymer polymethyl acrylic acid and polystyrene.Master of Science
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Mackey, Ryan M. E. "Soap film thickness imaging by infrared methods." Thesis, 1997. https://thesis.library.caltech.edu/220/1/Mackey_rme_1997.pdf.
Full textAbstract:
A new method of studying soap film flows is introduced and discussed from several viewpoints. Using a commercial infrared camera and a cold background as an infrared light source, one can recover nonintrusively a measurement of the film thickness distribution. Once the thickness is known it is easy to compute the two-dimensional pressure in the film, allowing one to compute other film properties as well.
Blackbody and infrared detector theory are covered in brief and a simple theory of operation is introduced to explain the connection between emissivity and thickness. This theory is demonstrated to behave similarly to the physical system, predicting detected temperature values as a function of thickness of the same approximate magnitude as observed, but is too simple to provide a perfect match. An empirical calibration routine is demonstrated allowing one to calculate the film thickness to a high degree of precision.
The infrared method is applied to a number of familiar test problems as a demonstration. A gravity driven soap film tunnel has been constructed, and infrared images of the film surface are provided for unobstructed flow, separated flow past a cylinder held at one wall, and turbulent flow through a grid. These images are presented in raw and processed formats and the phenomena observed are discussed.
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Peng, Chin-Chuan, and 彭進詮. "Thickness dependence multiferroics property ofBi0.9Pb0.1FeO3 thin film." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/50363233463438336357.
Full textAbstract:
碩士國立中山大學
物理學系研究所
98
In this study, we study the annealing effect of Bi0.9Pb0.1FeO3 bulk in various time span and the various growth conditions of Bi0.9Pb0.1FeO3 thin film to physical proporties, such as crystal structure, surface amorphous, delectric properties. With these effort, this study wish to find a better growth condition for Bi0.9Pb0.1FeO3 film that exhibit the best ferroelectric property, and to understant the possible mechanism underlaying the growth conditions to the physical properties. It is found that the doping of Pb in Bi0.9Pb0.1FeO3 compound does stabalize the formation of single phase Bi0.9Pb0.1FeO3 ,however, this stabalization can only postpone the decay of Bi0.9Pb0.1FeO3 properties when is annealed in a long period of time. The crystal strucutre of Bi0.9Pb0.1FeO3 is very close to a pseudocubic structure in which oxgyen sites locate noncenter-symmetrically that generates a stronge electric polariztion. The various growth conditions has a very stong influence to the physical properties of Bi0.9Pb0.1FeO3 thin films. For those films grwon at 700oC exibits the best delectricity. The grain size of films grows as grwoth time as resutl of this the thicker the film thelarger the grain size. The electric hysterises property measured by PFM is observed for grain itself, however, the grain boundaries where accumulates many possible defects exhibits a large electric leakage therefore no saturated polarization is observed if a large area of electrode is used.
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Huang, Pinxiang, and 黃品祥. "Effect of Film Thickness on Characteristics of Vacuum Annealed Titanium Dioxide Films." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/6n68qu.
Full textAbstract:
碩士崑山科技大學
電機工程研究所
107
In this thesis, borosilicate glass is used as the substrate, and different thicknesses of titanium dioxide film are deposited by sputtering. In the process of annealing, using plasma-assisted chemical vapor deposition system in high temperature and low pressure environment, the power of plasma power is 600W. The process gas pressure is 25 torr and the annealing time is 1 minute, and the effects on material structure, light transmittance and surface roughness characteristics are discussed. The UV-VIS-NIR optical measuring instrument spectrometer was used to analyze the change in optical properties. Through the analysis and comparison of the experimental results and various data, in the optical analysis, the visible light transmittance decreased to 91.57%, and the infrared reflectance increased from 10.38% to 13.37%. The surface morphology of the film changes due to optical effects. After the above-mentioned related data were compared, after the vacuum annealing treatment, the visible light transmittance and the infrared reflectance were annealed and the finished product was processed without being annealed, and no large optical change was observed.
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ZHOU, SHUI-YUAN, and 周水源. "Effect of Film Thickness on the Properties of Sputtered Titanium Dioxide Films." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/dmdu65.
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Gonçalves, David Emanuel Pimentel. "Polymer greases: film Thickness, Friction and Thermal Degradation." Doctoral thesis, 2016. https://repositorio-aberto.up.pt/handle/10216/85904.
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Chen, Chih-Cheng, and 陳志成. "Optical aberrations caused by non-uniform film thickness." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/94299034843213688655.
Full textAbstract:
碩士明新科技大學
電子工程研究所
96
This paper is composed of two parts, first the film thickness uniformity of the dome-type substrate is studied by simulating film thickness distribution theory . The other part optical aberrations caused by non-uniform film thickness are investigated by using Zernike polynomials fittings and simulations of film thickness distributions in different coating parameters.
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Gonçalves, David Emanuel Pimentel. "Polymer greases: film Thickness, Friction and Thermal Degradation." Tese, 2016. https://repositorio-aberto.up.pt/handle/10216/85904.
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Chen, Sin-Mao, and 陳欣懋. "Automatic in-site measurement system for thin film thickness." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/02086547524983420429.
Full textAbstract:
碩士國立雲林科技大學
機械工程系
104
Plastic film has six manufacturing process: mixing, extrusion, molding, cooling, embossing and cutting. Extrusion process control of film thickness. If film thickness non-uniformity will affect the quality. Therefore, in this process a thin film thickness monitoring is necessary. Traditional film thickness measurement mode is the use of micrometer.This method will not record production history and will cause measurement error. Thus,this research use capacitive displacement sensor and eddy current displacement meter developed thickness measurement system and it can test thickness measurement system. This thickness measurement system can be used in the film thickness measurement and it also has two advantages of improving measurement error and achieving real-time measurement. In order to verify thickness measurement capability of the system, its repeatability has been analyzed. Precision of thickness measurement system is 0.008 mm and deviation is -0.006 mm. Precision of in-site thickness measurement system is 0.05 mm and deviation is -0.044 mm.
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KU, HSUAN-YU, and 古烜瑜. "Analysis of Color and Thickness of Anodic Oxidation Film." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/7vzr23.
Full textAbstract:
碩士國立聯合大學
能源工程學系碩士班
105
Aluminum is a rich raw material,Because of lot production so it has often to be used. The aluminum alloy is also often used too, from 1 to 8 prefix has a wide variety of aluminum alloy,like Al-Cu,Al-Mn,Al-Mg,etc. This experiment uses 6061 aluminum alloy to do the surface treatment, altogether divides three major parts first mechanical polishing,electrolytic polishing,anodization. Anodic treatment is a mature technique it can grow anodic film on the metal surface, The film structure has a nano-hole it Covered with all the range, the film thickness hole size Colour can be changed with the time of the anode treatment and different electrolyte. This experiment uses sulfuric acid and phosphoric acid on Anodic treatment, Change the voltage parameter in the anode treatment made 6061 aluminum alloy produce a variety of colors, Then use the thin film measuring instrument to do the measurement and then set up the color data.we use LAB witch proposed by International Commission on illumination, we use LAB is better than RGB it can reduce the errors,when the data was be found we can Calculation the hue-angleand chroma to discuss how it change. There are also discuss thin film thicknesses grown in different voltage solutions.
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呂家豐. "Investigation of thickness uniformity of the rolled polymer film." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/71874384937837755846.
Full textAbstract:
碩士國立交通大學
機械工程學系
100
Roll Forming is an important process in the domain of the polymer processing , simply is widely used in manufacturing processes to increase the life of plates and film . In recent years , various rolling processes for forming polymer film have been developed . However, as with the product thickness decreases , achieving the required accuracy is extremely challenging . This study analyzed polymer film characteristics in terms of roll parameters , film thickness , the response rate of film and bubble generation . Roller parameters were compared between different phenomena as an important indicator of the roller for use in , future designs for improving operation and maintenance . This study also designed new polymer material rolling equipment to achieve uniform thickness in rolling process . Operational parameters analyzed for the roller included the cooling temperature of roller , roller speed and the roll gap between the rollers . The objective was to optimize parameters needed to achieve a good surface quality and a uniform thickness in the polymer film . The experimental results show that , given a similar roll gap and roller surface temperature , the difference in improvements at the ends increases as the roll speed of the film specimen decreases . Given a similar roll gap and roll speed of the film specimen , overall uniformity of roller thickness increases and response rate decreases as the surface temperature of the roller increases . Additionally , as the roll gap decreases , the difference in thickness at the ends of the specimen decreases . The experimental results of this study provide a reference for improving roller devices and polymer roll accuracy .
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陳貴聖. "Development of Film Thickness Monitoring System for Inflation Machine." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/33844508765365130585.
Full textAbstract:
碩士國立彰化師範大學
電機工程學系
102
Abstract The invention of plastic bag is a very important technology revolution in human history. For a century, plastic bags have become convenient packing product with the feature of dust-proof and moisture-proof in living or for the industry. Although many policies limit the development of plastic bags due to environmental protection, plastic bags have the feature of light and cheap comparing to paper bags or other materials. Therefore, it is more important to make good use of plastic bags than to limit the usage of plastic bags for simple living. The material of plastic bags is made by high molecular polymer and classified into low density polyethylene (LDPE), high density polyethylene (HDPE), and PolyproPylene (PP)etc. based mostly on its density and branching. Its mechanical properties depend significantly on variables such as the extent and type of branching, the crystal structure and the molecular weight. The study aims to improve the measurement of monitoring film thickness in the process of making film for HDPE inflation machine. By applying efficient technique to replace conventional manual measurement, it is expected to decrease the film thickness adjusting time and reduce 30% of defect rate for product efficiency. The experimental result proves that the proposed on-line measurement module can improve the precision rate of plastic thickness to 6%~10% and reduce the size adjusting time for more than 10 minutes. The defect improvement efficiency can reach up to 52%. Keyword: Inflation machine, Film thickness, Thickness measurement
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Lee, Kang-Chaung, and 李康莊. "The Effect Of Electric Field On Polymer Film Thickness." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/86312809928328795505.
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Liao, Bo-Sheng, and 廖柏昇. "Flow Control of Constant Thickness Film for a Hydrostatic." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/80707538519128037417.
Full textAbstract:
碩士中原大學
機械工程研究所
103
In this paper, hydrostatic bearing oil film thickness to maintain a uniform film does not change and all research and development goals, discuss controlling the flow speed of the displacement pump control laws to solve uneven film thickness and the film thickness becomes a problem with the load to the bearing carrier four displacement of a point, as the feedback signal flow and establish control methods hydrostatic bearing sub-systems. In this paper,LabView software to establish the sensing and control of man-machine interface to sense feedback and calculated program to achieve and so the film thickness control.
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Vieira, António Patrício Pinto do Couto. "Film thickness and friction in grease lubricated rough contacts." Master's thesis, 2017. https://repositorio-aberto.up.pt/handle/10216/106459.
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