Dissertations / Theses on the topic 'Foam printing'
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Hu, Xusheng. "Study of the Thermal Performance of Metal Foam and PCM Composite for Thermal Energy Storage." Thesis, Troyes, 2021. http://www.theses.fr/2021TROY0003.
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Le but de cette thèse est d'étudier les performances thermiques d'une mousse métallique ainsi que de ses composites avec un matériau à changement de phase (MCP) en utilisant des méthodes expérimentales et numériques. La mousse métallique étudiée possède une structure cellulaire cubique. Les effets des conditions de contact et de chaleur sur le taux de stockage de chaleur dans le composite MCP sont d’abord simulés numériquement. Ensuite, la mousse métallique avec une structure cellulaire cubique est conçue et fabriquée par impression 3D. L'étude expérimentale permet par la suite d’observer l'évolution de la fusion du MCP introduit dans la mousse métallique. Parallèlement, une méthode numérique à l'échelle des pores est utilisée pour simuler les caractéristiques de transfert thermique dans le composite MCP. Il ressort des résultats que la mousse métallique d'enrobage peut réduire le temps total de fusion du matériau MCP. Compte tenu de l'influence des paramètres de morphologie de la mousse métallique, nous avons étudié numériquement le comportement thermique de la mousse métallique en variant la porosité et la densité de pores. La dernière partie de cette thèse consiste à explorer une application de la mousse métallique dans les dissipateurs thermiques à base de MCP. Les essais expérimentaux sur composite MCP permettent d’obtenir la réponse thermique des dissipateurs thermiques. Les effets de la porosité de la mousse métallique et de la puissance du chauffage sur la réponse thermique du dissipateur thermique sont également mis en évidenceThe aim of this Ph.D. thesis is to study the thermal performance of metal foam and phase change material (PCM) composite by using the experimental and numerical methods, in which metal foam possesses a cubic cell structure and is fabricated by 3D printing technique. Firstly, the effects of contact and heat conditions on heat storage rate of PCM composite are investigated to provide theoretical guidance for the practical application of PCM composite in thermal energy storage (TES) system. Then the metal foam with a cubic cell structure is designed and fabricated by 3D printing. The experimental investigation is carried out to examine the melting evolution of PCM embedded in metal foam. Meanwhile, the pore-scale numerical method is also proposed and used to investigate heat transfer characteristics of PCM composite. It is found from the results that the embedding metal foam can short the total melting time of PCM. Considering the influence of morphology parameters of metal foam, the thermal behavior of metal foam with different porosities and pore densities is numerically studied. The last part of this thesis explores the application of metal foam in PCM based heat sink. The thermal response of heat sinks using PCM composite is obtained by the experimental test, including base temperature, temperature variation, operating time and enhancement ratio of operating time. Also, the effects of the porosity of metal foam and the power level of the heater on the thermal response of heat sink are investigated
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Sundaram, Subramanian Ph D. Massachusetts Institute of Technology. "3D-printing form and function." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120416.
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Thesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 153-171).
Integrating diverse functions inside man-made parts with specific shapes, in a highly scalable manner, is the central challenge in manufacturing. Functional integration is typically achieved by assembling specialized parts, each independently made using carefully designed production techniques - for example, in assembly lines in the automotive industry. Externally assembling specialized parts is tedious at certain length scales (e.g. mesoscale manufacturing), imposes restrictions on achievable geometries, and limits functional integration. In contrast, nature excels at packing disparate materials and functions into unconstrained geometries across different length scales (e.g. distributed sensors in cuttlefish, or sensorimotor pathways and resonant muscles in insects). These far exceed our current fabrication capabilities, and replicating all the functions of natural systems has remained a distant dream. 3D-printing has resolved many challenges in fabricating complex geometries, but despite its promise, assembling diverse materials (including solids, liquids and thin-films) and functions inside a single, printed composite is a current challenge. This thesis presents a set of materials, processes and design strategies - a full experimental toolkit - to address the question: how can we distribute diverse materials and functions in free-form geometries? First, a fully-3D-printed autonomous composite that can sense an external stimulus, process it, and respond by varying its optical transparency is described. The composite consists of seamlessly integrated solids (UV-cured polymers), thin-films (conducting and semiconducting, solvent-evaporated films), and encapsulated liquids. Techniques to engineer material interfaces are also presented in this section. A stimulus-free strategy to 3D-print self-folding composites at room temperature is presented in the second part of this thesis. Specifically, the focus is on printing flat electrical composites that fold into pre-programmed shapes after printing using residual stress defined in specific regions. This provides advantages in the fabrication speed, and also expands the range of achievable geometries when using solvent-based inks. The third portion of this thesis focuses on 3D-printing soft actuators. After highlighting a few example applications of printed actuator arrays, this is used as a case study for topology optimization based design strategies. It is shown that the inclusion of a topology optimizer in the 3D-printing pipeline enables the automated design and fabrication of high-dimensional designs. The final section of this work focuses on creating tactile sensor arrays, with an emphasis on the acquisition of tactile datasets that can be used to understand the human grasp. The concluding section summarizes the role of the fabrication strategies presented here in creating composites of increasing levels of autonomy and self-sufficiency.
by Subramanian Sundaram.
Ph. D.
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Leines, Kevin B. "The influence of the position of a color control bar on a form when determining the most appropriate location to measure variability in solid ink density and dot gain of a printed product /." Online version of thesis, 1990. http://hdl.handle.net/1850/10926.
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Abd-el-Kader, Magdy Ezzat. "Application of hot melt ink jet processes for imaging at offset printing form cylinder." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=970645775.
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Abd, El Kader Magdy Ezzat. "Application of Hot-Melt Ink Jet Processes for Imaging at Offset Printing Form Cylinder." Doctoral thesis, Universitätsbibliothek Chemnitz, 2004. http://nbn-resolving.de/urn:nbn:de:swb:ch1-200400092.
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The present work related to apply hot-melt ink-jet process for imaging at offset lithographic printing form, to utilise a reusable surface for many times and particularly related to validating thermal and ultrasonic erasing processes. This dissertation investigated systematically the role of certain factors towards affecting erasing image area process on print surfaces. Thermal erasing process approved to melt and suck the image area from the surface, the results were adopted by using contact angle measurements and scanning electron microscope. Ultrasonic erasing process permitted to solve the image area by choosing erasing chemistries, influence of selected erasing chemistries on printing surface, and evaluation the process, the results were tested by UV/Vis spectrometer, contact angle, profileometery and visual microscopeDer Fortschritt im Bereich von Charakterisierung und Verständnis für Hot-melt Ink Jet Prozesse zur Bebilderung von Offsetdruckform-Zylindern ist ein Ergebnis dieser Forschung. Die Systematik dieser Arbeit basiert auf einem theoretischen Teil, um einen geeigneten Löschprozess auszuwählen. Der Löschprozess hängt von den Eigenschaften des Hot-melt Ink Jet Materials und der genutzten Aluminiumdruckoberfläche ab. Diese werden systematisch im Labormaßstab experimentell untersucht. Der thermische Prozess wurde einerseits durch Benetzbarkeitsprüfungen und anderseites durch Rasterelektronmikroskopaufnahmen bewertet.Der Ultraschallprozess ist ein nasser Löschprozess. Die Untersuchungen wurden in vier Stufen systematisch durchgeführt - Auswahl vom geeigneten Lösungsmitteln - Einflüsse von ausgewählten Lösungsmitteln auf nicht beschichtete und beschichtete Aluminium platten - Evaluation eines Ultraschalllöschprozesses - Validation eines Löschprozesses; zur Bewertung des Löschprozesses wurden mehrere Druckplattenproben bebildert und gelöscht Die Ergebnisse wurden durch UV/Vis Spektrometer, Kontaktwinkel, Profiliometrie und Visuelle Mikroskopie getestet
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Al-Hachami, Wathiq. "Investigation of pico-litre inkjet printing for nano-gram scale solid form screening of pharmaceuticals." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/52031/.
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The tendency of the majority of active pharmaceutical ingredients (APIs) to exist in different solid forms with keeping their chemical structures is called polymorphism. This phenomenon has gained a lot of interest in the pharmaceutical industry, hoping to avoid producing unexpected transformations of compounds during and after synthesis. The optimal way to avoid that is to subject the API, at the early stage of development, under various conditions in order to obtain an elegant (safe, effective, and stable) drug for the next formulation step. The aim of this thesis was to investigate some factors that affect the appearance of different polymorphs during screening of some APIs. Four model drugs were selected: paracetamol; carbamazepine; mefenamic acid; and flufenamic acid. All have been well-characterised previously in terms of solid-state forms. Piezoelectric, or 2D inkjet printing technique was used as a main technique in fabrication of nanoarrays of APIs onto predefined design on a solid tunable substrates because of its ability to control the delivered quantities of the the printed materials accurately, without any direct contact with the used substrate that may cause a sample cross-contamination. Light optical microscope was used to investigate the behaviour of the printed droplets during and after solvent evaporation and turn to dried spots, and to confirm the crystalline state of some spots by using the polarised light in the same microscope. Raman spectroscopy at low-wavenumber, or phonon region (40-400 cm-1) was used for the first time to identify the resulted polymorphs after the printing process as its ability to probe the alterations that happen in the molecular skeleton inside the crystal lattice , in addition to molecular region (400-1800 cm-1) to analyse the resulting spots. In chapter three, the piezoelectric inkjet printing technique was successfully used for the first time to miniaturise, screen, and study the stability of the APIs at nano quantities in the range of (1-500 ng), about six-ordered magnification less than the reported studies. It was found that the variation in the printed quantities can produce different states and polymorphs. Stability with time was also studied for all the printed samples and it was noticed the variation in time for some printed drugs to convert from solid amorphous to crystalline state. In chapter four, the advantage of the ability of the gold-coated slide to undergo further chemical modifications was exploited to create new substrates. Chemical modification of the gold substrates was carried out by treating them with two types of thiols to form self-assembly monolayers (SAMs) and use them as substrates in polymorph screening of some APIs. The new prepared SAMs were examined by preliminary tests like atomic force microscope (AFM) and water contact angle (WCA) measurements to investigate the texture of the new substrates before using them in printing process. It was found that changing the chemical structure of the substrate can lead to different polymorphs. In chapter five, an attempt to create highly hydrophobic substrates was done to investigate whether it can affect the propensity of APIs for polymorphism. Fluorinated compounds were used in this chapter as they are considered more hydrophobic than the substrates used in the previous part of the work The effect of the fluorinated substrates on appearance of new polymorphs was studied. Two fluorinated compounds were selected for preparation of high-water repellent surfaces and using them as substrates as they have the ability to limit the spreading of the printed droplets of the API, and allow the molecules to be constructed layer by layer and form a condense spot. The new fluorinated substrates were examined before using them in printing, and they exhibited high WCA. Another FLUF polymorph (VI) was investigated in addition to the two reference (I and III) polymorphs used in FLUF polymorphic screening. It was found that the intensity of the Raman peaks of the printed spots of APIs was good and clear to recognise when using fluorinated SAMs as a substrate, while the fluorinated substrate prepared from Flutec LE15 exhibited fluorescence effect due to the interactions between the glass and the drug’s spot spectrum.
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Gissibl, Timo [Verfasser], and Harald [Akademischer Betreuer] Giessen. "3D printing of sub-micrometer accurate ultra-compact free-form optics / Timo Gissibl ; Betreuer: Harald Giessen." Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2016. http://d-nb.info/1183678215/34.
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Hempson, Garth Jake. "The naturally imperfect form : investigations of the application of digital sculpting methods - extracted art : incorporating and translating ‘found art’ into the medium of digital sculpture." Thesis, Queensland University of Technology, 2012. https://eprints.qut.edu.au/60246/1/Garth_Hempson_Thesis.pdf.
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This dissertation analyses how physical objects are translated into digital artworks using techniques which can lead to ‘imperfections’ in the resulting digital artwork that are typically removed to arrive at a ‘perfect’ final representation. The dissertation discusses the adaptation of existing techniques into an artistic workflow that acknowledges and incorporates the imperfections of translation into the final pieces. It presents an exploration of the relationship between physical and digital artefacts and the processes used to move between the two.
The work explores the 'craft' of digital sculpting and the technology used in producing what the artist terms ‘a naturally imperfect form’, incorporating knowledge of traditional sculpture, an understanding of anatomy and an interest in the study of bones (Osteology).
The outcomes of the research are presented as a series of digital sculptural works, exhibited as a collection of curiosities in multiple mediums, including interactive game spaces, augmented reality (AR), rapid prototype prints (RP) and video displays.
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Xu, Shang. "Investigations into the Form and Design of an Elbow Exoskeleton Using Additive Manufacturing." Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103204.
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The commercial exoskeletons are often heavy and bulky, thus reducing the weight and simplifying the form factor becomes a critical task. This thesis details the process of designing and making a low-profile, cable-driven arm exoskeleton. Many advanced methods are explored: 3D scanning, generative design, soft material, compliant joint, additive manufacturing, and 3D latticing. The experiments on TPU kerf cut found that the stress-strain curve of the sample can be modified by changing the cut pattern, it is even possible to control the linear region. The TPU TPMS test showed that given the same volume, changing the lattice parameters can result in different bending stress-strain curves. This thesis also provides many prototypes, test data, and samples for future reference.Master of Science
Wearing an exoskeleton should be easy and stress-free, but many of the available models are not ergonomic nor user-friendly. To make an exoskeleton that is inviting and comfortable to wear, various nontraditional methods are used. The arm exoskeleton prototype has a lightweight and ergonomic frame, the joints are soft and compact, the cable-driven system is safe and low-profile. This design also brings aesthetics to the exoskeleton which closes the gap between engineering and design.
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Dickman, Daina Elizabeth. ""I'd created my own truths by printing my zine." Women-written Perzines as a narrative form for disclosure and advice giving." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406717512.
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Svatík, Juraj. "Funkční pěny s gradientem hustoty." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2019. http://www.nusl.cz/ntk/nusl-401848.
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Vycházíme-li z lehčených přírodních materiálů, lze od porézních materiálů s gradientem porozity očekávat mechanické vlastnosti nadřazené konvenčím polymerním pěnám, a to díky jejich specifické architektuře. Tyto vlastnosti umožňují použití lehčených materiálů jako strukturních prvků. V této práci je popsaná příprava gradientních porézních materiálů pomocí laminování a/nebo 3D tisku. Provedeny byly statické a dynamické mechanické testy na obou kvazi homogenních a gradientně porézních pěnách poskytující experimentální podklad pro hypotézu deformační odezvy plynoucí ze strukturní architektury. Data se interpretovala užitím zavedených teoretických modelů. Naše výsledky vedly k závěru, že tyto teoretické modely odvozené od pěn s pravidelnou strukturou není vhodné aplikovat pro pěny s gradientem porozity, protože prokazují podstatně lepší mechanické vlastnosti než homogenně porézní pěny.
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Režnáková, Ema. "Příprava a charakterizace lehčených polymerních materiálů s hierarchickou celulární strukturou." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2020. http://www.nusl.cz/ntk/nusl-414127.
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The asymmetrical arrangement of cellular structure allows for an accurate functional adaptation at all levels of hierarchy, which derives excellent features for the development of new materials. The main objective of introducing a hierarchy into cellular structures is to improve the mechanical behaviour of the material while maintaining its elastic properties. A part of this work is devoted to the literature review related to the lightened cellular polymeric materials with hierarchical cellular structure. The rest is focused on the preparation of PLA based polymer structures using 3D printing, followed by a saturation in CO2 and a foaming in a silicon oil at elevated temperature. Samples were prepared from natural and white PLA filaments. Based on a series of experiments, optimal conditions for the saturation and foaming process were identified. Through 3D printing and foaming, a one-, two- and three-level hierarchy was introduced into the beam-shaped samples and the effect of the internal cell arrangement on the strain response of the material was examined by the means of a mechanical three-point bending test. Increasing the level of the hierarchy led to an increase in material resistance, which resulted in high values of strength and strain energy (toughness) based on the samples density. The best results were achieved by samples with “sandwich” structure with three levels of hierarchy and 30% filling. Despite the shorter plateau, there was a significant increase in strength and strain energy compared to gradient structures. At the same time, the contribution of the polymer structures prepared in this field of research was demonstrated by comparison with the theoretical model.
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Zhang, Chuan. "Aluminum foams composite : elaboration and thermal properties for energy storage." Thesis, Troyes, 2017. http://www.theses.fr/2017TROY0015/document.
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L'objectif de cette thèse est d'étudier et d'optimiser le processus de fabrication des mousses métalliques et le comportement thermique du matériau de la mousse d'aluminium/matériau de changement de phase (MCP) par des méthodes expérimentales et numériques. Le processus d’élaboration de la mousse d’aluminium à pore ouvert est développé et optimisé pour contrôler précisément les paramètres de fabrication. Deux modèles de mousse d'aluminium à haute porosité (MAHP)/MCP composite et à faible porosité (MALP)/MCP composite sont établis pour la simulation numérique. En simulant le processus de fusion d'un système de stockage d'énergie, les composites MAHP/MCP et MALP/MCP sont comparés numériquement afin d'évaluer la performance de stockage d'énergie thermique. Les résultats montrent que la mousse d'aluminium améliore nettement le processus de transfert de chaleur dans MCP en raison de sa haute conductivité thermique. La porosité des mousses d'aluminium influence non seulement le processus de fusion du composite mais aussi la performance de stockage d'énergie thermique. Grâce à la collaboration avec EPF, une nouvelle méthode d’élaboration des mousses périodiques d'aluminium à pore ouvert est développée dans cette thèse sur la base d’impression 3D. Le comportement thermique des mousses d'aluminium périodiques à pore ouvert/MCP est analysé expérimentalement et numériquementThe objective of this thesis is to study and optimize the manufacturing process of metal foams and the thermal behavior of the aluminum foam/phase change material (PCM) composite by experimental and numerical methods. The manufacturing process of open-cell aluminum foam is developed and optimized to precisely control the parameters of mufacturing. Two pore-scale models of high porosity aluminum foams (HPAF)/PCM composite and low porosity aluminum foams (LPAF)/PCM composite are established for numerical simulation. By simulating the melting process of a layer energy storage system, the HPAF/PCM and LPAFS/PCM composite are compared numerically in order to evaluate the energy storage performance. The results show that aluminum foam improves greatly the heat transfer process in PCM due to its high thermal conductivity. The porosity of aluminum foams could not only influence the melting process of composite but also the energy storage performance. Thanks to the collaboration with EPF, a new manufacturing method of periodic open-cell aluminum foams is developed based on 3D rapid tooling. The thermal behavior of the periodic open-cell aluminum foams/PCM composite is experimentally and numerically analyzed
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Jourdan, David. "Conception numérique de textiles auto-déployables." Thesis, Université Côte d'Azur, 2022. http://www.theses.fr/2022COAZ4008.
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L'impression sur tissu est une technique de fabrication récente consistant à déposer sur un tissu étiré du plastique en fusion en utilisant des procédés standard de fabrication additive. L'impression sur tissu a récemment gagné en popularité car c'est une technique de fabrication peu coûteuse permettant de créer des structures déployables qui prennent automatiquement une forme en 3D lorsque le tissu est relâché. Le comportement en déformation de ce matériau composite peut s'expliquer par des phénomènes de frustration de métrique que nous décrivons dans la suite de cet exposé. Nous exploitons ces phénomènes pour proposer plusieurs applications aidant à la conception de structures auto-déployables légères.La première application présentée est un outil de design pour fabriquer des maquettes architecturales légères basé sur un pavage de motifs en étoile dans lequel les dimensions (et donc les propriétés physiques) de chaque élément varient dans l'espace. Les utilisateurs de ce système peuvent créer des formes libres en ajustant le motif d'étoiles ; notre système simule ensuite le couplage entre le tissu et les motifs de plastique pour traduire les paramètres en design en variations de forme.L'outil de simulation introduit précédemment est ensuite généralisé pour pouvoir s'appliquer à tous types de motifs imprimés et pas seulement des motifs en étoile. Nous modélisons notamment l'anisotropie du tissu ainsi que l'effet bilame causé par le différentiel de compression à l'interface entre la couche de plastique et la couche de tissu.Pour finir, une méthode de design inverse capable de reproduire des formes cibles en imprimant un motif dense de rubans peu espacés est présentée. Le cœur de la méthode consiste en un algorithme de paramétrisation qui borne les distorsions locales de surface le long des directions principales de courbure, ainsi qu'un algorithme de synthèse de motifs qui couvre la surface de rubans pour respecter les distorsions cibles et la courbure données par la paramétrisationPrinting-on-fabric is a recent manufacturing technique which consists in extruding molten plastic into pre-stretched fabric using standard additive manufacturing technologies. Printing-on-fabric recently gained popularity as a low-cost fabrication technique for designing deployable structures which can pop out of shape when the fabric is released. The complex morphing behavior of this composite material can be explained by metric frustration phenomena which are described in this thesis. We leverage these phenomena to build several applications aiding the design of self-actuated, lightweight structures.We first present a (forward) design tool for fabricating lightweight architectural models based on a tiling of star patterns, with the dimensions (and hence physical properties) of the individual pattern elements varying over space. Users of this system design free-form shapes by adjusting the star pattern; our system then automatically simulates the complex physical coupling between the fabric and stars to translate the design edits into shape variations.We then extend the form-finding tool to a general-purpose simulation method that can predict the buckling behavior of a variety of printed-on-fabric designs besides star tilings. We show the importance of modelling the bilayer effect caused by the differential compression at the interface between the plastic and fabric layers, as well as the anisotropic properties of the fabric.Finally, an inverse design tool that is able to reproduce target shapes with printing-on-fabric using a dense pattern of closely-spaced ribbons is introduced. The core of this method is a parameterization algorithm that bounds surface distortions along and across principal curvature directions, along with a pattern synthesis algorithm that covers a surface with ribbons to match the target distortions and curvature given by the aforementioned parameterization
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Trnovec, Bystrik. "Experimentelle Untersuchungen zur Schichtbildung im Tiefdruck mittels hydrophobierter Druckform mit Applikationsbeispielen aus dem Bereich der gedruckten OPV." Doctoral thesis, Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-209748.
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Die vorliegende Arbeit beschreibt eine experimentelle Untersuchung der Schichtbildung von nichtnewtonschen Flüssigkeiten im Tiefdruckverfahren auf nicht saugfähigen Substraten. Das fluiddynamisch bedingte „viscous fingering“ beim Farbspaltungsprozess soll mittels Hydrophobieren der Druckform gehemmt werden. Ziel ist es, möglichst homogene sowie wellenfreie Schichten zu erzeugen. Um ein direkt miteinander vergleichbares Druckergebnis zu erhalten, wird der Druckstoff parallel mit einer unbehandelten und hydrophobierten Form bedruckt. Als Druckstoff werden anstelle von Druckfarbe funktionale Materialien (vorzugsweise PEDOT:PSS) verwendet und variiert, wobei die elektrischen und geometrischen Schichteigenschaften, beispielsweise der elektrische Widerstand und die Rauheit, zur Ermittlung der gesetzten Ziele untersucht wurden. Hiermit und mittels Nutzung einer hydrophobierten Druckform kann eine deutliche Minderung der Wellenbildung (viscous fingering) bei vielen Druckstoffarten beobachtet werden. Die Minderung des viscous fingering im Farbspaltungsprozess und eine nahezu vollständige Leerung der hydrophobierten Tiefdruckform haben einen wesentlichen Nutzwert für den künftigen Einsatz nicht nur für die „gedruckte Elektronik“In this work is described experimental research about layer forming from non-Newtonian fluids in gravure printing on non-porous substrates. The viscous fingering, caused through fluid dynamics at splitting of printed material should be decreased by hydrophobic-surface modification of gravure printing form. The aim was to print wave-free homogenous layers. To achieve comparable results, modified and pure form were used simultaneously to print the same material. The printed material was mainly PEDOT:PSS and other, which is used in printed electronics. The properties (surface tension, viscosity) of printed materials were varied by additives. Printing conditions were varied too. The characteristic of printed layers were studied: resistivity, roughness, density, etc. The results shows decreasing of waviness, roughness and viscous fingering in final layer through use of hydrophobic gravure printing form, compared to print results with common printing form. This can be applied not only in the field of printed electronics
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Taborda, Sérgio. "Percepção e presença-o corpo na escultura, cinema e biotecnologias." Master's thesis, Instituições portuguesas -- UNL-Universidade Nova de Lisboa -- FCSH-Faculdade de Ciências Sociais e Humanas, 1999. http://dited.bn.pt:80/29026.
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Musil, Jiří. "Hledání tvaru skořepinových konstrukcí." Doctoral thesis, Vysoké učení technické v Brně. Fakulta stavební, 2017. http://www.nusl.cz/ntk/nusl-390254.
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The theme of this doctoral thesis is the design of concrete shell structures with the focus on finding their optimal shape. The optimal shape of a concrete shell is the shape in which for a given load (usually the dead weight of the structure) no significant bending moments are generated in the shell and the structure is in the so-called membrane state. The inspiration for this thesis is the work of Swiss engineer Heinz Isler, who developed the shapes of shell structures using model tests of appropriately loaded flexible membranes. He developed the shell structure for large spans by inverting the resultant shape, which carried its weight almost entirely via membrane forces. The numerical solution of the above experiments using Midas Civil is presented herein. The basic principles of the method are demonstrated on the example of sagged cable. The numerically found shapes are compared with the analytical solution. A shell is designed based on the numerically found shapes and its stress response to dead load is described, particularly in relation to the membrane action. In the next part, the acquired knowledge and methods were used to design three relatively complicated shell structures. Each structure was statically analysed and its static behaviour was described. Structures with perfectly rigid or flexible supports, which simulate real behaviour of the supports, were studied. In the final phase, the results of static analysis of the selected shell were experimentally verified on a physical model in a scale of 1: 55.56. The model has been built using 3D printing. The thesis describes the use of a modelling similarity, the model design, the production process, and the experiment. The load test confirmed the optimal design of the shell structure and the validity of the numerical method for finding their shapes.
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Liu, Eunice. "Design gráfico: processo como forma." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/16/16134/tde-14102013-154730/.
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Criatividade no uso de recursos de impressão, reprodução, gravação, acabamento gráficos, editorial, encadernação e materiais, em design gráfico, denominados processos, é o tema desta pesquisa. A investigação procede de projetos resultantes da prática disciplinar e é documentada por imagem, fotografias, para ciência visual. Estudos técnico, formal (relativo à forma) e projetual investigam relações entre processo e forma, resultando em um repertório de parâmetros e possibilidades. Forma pura é gráfica e a construída, matéria conformada por processos, meios de produção pelos quais se trabalha forma. Conhecimentos de processos são recursos de projeto, e apropriações criativas destes, qualificam um bom designCreativity in the use of printing, reproduction, engraving, graphic finishings, editorial, binding and material resources in graphic design, denominated processes, is the theme of this research. The investigation is originated by projects, product of disciplinary practice, and is documented by image, for visual science. Technical, formal (related to form), and project studies explore relationships between process and form, resulting in a repertoire of parameters and possibilities. Pure form is graphic and constructed form, material shaped by processes, means of production by which form is tooled. The knowledge of processes is project resources, and creative appropriations of them, qualify a good design
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Barajas, Leandro G. "Process Control in High-Noise Environments Using A Limited Number Of Measurements." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/7741.
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The topic of this dissertation is the derivation, development, and evaluation of novel hybrid algorithms for process control that use a limited number of measurements and that are suitable to operate in the presence of large amounts of process noise.
As an initial step, affine and neural network statistical process models are developed in order to simulate the steady-state system behavior. Such models are vitally important in the evaluation, testing, and improvement of all other process controllers referred to in this work. Afterwards, fuzzy logic controller rules are assimilated into a mathematical characterization of a model that includes the modes and mode transition rules that define a hybrid hierarchical process control. The main processing entity in such framework is a closed-loop control algorithm that performs global and then local optimizations in order to asymptotically reach minimum bias error; this is done while requiring a minimum number of iterations in order to promptly reach a desired operational window.
The results of this research are applied to surface mount technology manufacturing-lines yield optimization. This work achieves a practical degree of control over the solder-paste volume deposition in the Stencil Printing Process (SPP). Results show that it is possible to change the operating point of the process by modifying certain machine parameters and even compensate for the difference in height due to change in print direction.
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葉曾欽. "The study on the foam printing of polyester fabrics." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/66085466852756313324.
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Su, David, and 蘇育才. "A STUDY OF SUITABILITY OF SCREEN PRINTING ON MEDICAL POLYURETHANE FOAM." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/23442098592862453255.
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碩士世新大學
圖文傳播暨數位出版學研究所(含碩專班)
95
The printed manufacture of the medical apparatus belonged to one of a more special circle of a printing industry. For the cloth on the medical air cushion bed, the artificial cloth coating the Foaming Polyurethane. To research for the suitableness of applied to halftone printing. To find out a better printing suitableness matched with a safety standard and medical apparatus. According to three tests for the printed material as below: printing ink peeled off test, alcohol-resistant test and 95oC high-temperature ageing water-washes test, proceeded the following variables: to allocate the percentage of ink and assistant, to change the temperature and speed of dry an ink to find out a better way to fit for a mass product. 1. Peel off degree: According to an experiment, we found to control the following two conditions then we could get the best adhered ability and the shrinkage of cloth could be in the limitation tolerance. (a) To bake it and control the temperature between 50 oC ~ 60 oC. (b) To control the dry speed between 1 M/min ~ 1.5 M/min. 2. Alcohol-resistant: The data which was paired by intersected a baked temperature and speed can temporary dry the surface of printing ink in the experiment. (It will be slowly dried inside depended on the static placed time.) So the dry surface didn’t be destroyed when we wiped it with alcohol. Therefore it can be pass the Alcohol-resistant test. 3. High-temperature ageing water-washes: It was required that ink did not fall off after water-washes for 20 times at 95 oC. We knew we had to add a hardener into the printing ink in order to get the best adhered ability. The ratio was Ink : Slow-Dry Solvent : Hardener = 10 : 1 : 1 For the monochroic print, there was obviously variation after two days. So it could reach the request of the experiment. For the piles of color print, it would better control the printing time-gap of the fore and hind colors within 4 hours. And it was placed statically for more than 2 days after print. Therefore it could match with the request. To sum up all results as the above, we knew - to control the baked temperature between 50 oC and 60 oC - to control the baked speed between 1 M/min and 1.5 M/min - to add Hardener into Ink. Ratio: Ink : Solvent : Hardener = 10 : 1 : 1 - to control the printing time-gap of the fore and hind colors within 4 hours for the piles of color printing - to place statically for more than 2 days after print. then we can got the best adhered effect.
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Wang, Shang-Tong, and 王上通. "Improving Form-Printing Software Maintenance by Maintenance-Oriented Design." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/85022192903962741134.
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碩士國立中興大學
資訊網路多媒體研究所
100
Software maintenance cost has always accounted for a large share of total software cost. Study has shown that optimizing software maintenance should begin at the software planning phrase by evaluating the software maintenance problems. The main goal is to improve software maintainability and to reduce the probability of maintenance requirements. Yet most mathematic researches in the past had focused on managing software maintenance after its occurrence. The tasks associated with software maintenance can be divided into corrective maintenance caused by errors in software construction, or adaptive and comprehensive maintenance needed for software that can yet accommodate future technical requirements. Errors in software construction can be effectively corrected via software engineering; it is the insufficient software adaptability that requires the most maintenance, and there is a lack of research and useable techniques associated with this problem. The purpose of maintenance-oriented design is to reduce the occurrence of software maintenance to optimize the goal of software maintenance engineering. User experiences are analyzed to offset the inability to identify every possible demand by the users. Software maintenance occurrences are reduced and means of resolving the problems are provided based on sample occurrences that have occurred. The common mandatory basic functions are then selected and pre-established in the software system to strengthen software adaptability. Information and software structures are then generically designed so that information processing signs and functions are separately composed. This way it would be easier to maintain software structure, information processing can be generically designed, and users would be allowed to customize the user interface for information processing. Customization can better satisfy user need, and these methods will help reduce the occurrence of software maintenance. This study utilized maintenance-oriented design and tested using generic form-printing software. The result showed that generically designed form-printing software can process the items to be printed without constraints, and would only require software maintenance when information processing ability is sufficient for unknown form formats, as new capability would have to be added to process that information. This type of design can reduce both the probability and cost of software maintenance.
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Nascimento, Nuno Alexandre Mota Ferreira Pereira. "Numerical and Experimental Analysis of Polymeric Foams obtained by 3D Printing (Additive Manufacturing)." Master's thesis, 2019. https://hdl.handle.net/10216/122455.
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Abd, El Kader Magdy Ezzat. "Application of Hot-Melt Ink Jet Processes for Imaging at Offset Printing Form Cylinder." Doctoral thesis, 2003. https://monarch.qucosa.de/id/qucosa%3A18099.
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The present work related to apply hot-melt ink-jet process for imaging at offset lithographic printing form, to utilise a reusable surface for many times and particularly related to validating thermal and ultrasonic erasing processes. This dissertation investigated systematically the role of certain factors towards affecting erasing image area process on print surfaces. Thermal erasing process approved to melt and suck the image area from the surface, the results were adopted by using contact angle measurements and scanning electron microscope. Ultrasonic erasing process permitted to solve the image area by choosing erasing chemistries, influence of selected erasing chemistries on printing surface, and evaluation the process, the results were tested by UV/Vis spectrometer, contact angle, profileometery and visual microscope.Der Fortschritt im Bereich von Charakterisierung und Verständnis für Hot-melt Ink Jet Prozesse zur Bebilderung von Offsetdruckform-Zylindern ist ein Ergebnis dieser Forschung. Die Systematik dieser Arbeit basiert auf einem theoretischen Teil, um einen geeigneten Löschprozess auszuwählen. Der Löschprozess hängt von den Eigenschaften des Hot-melt Ink Jet Materials und der genutzten Aluminiumdruckoberfläche ab. Diese werden systematisch im Labormaßstab experimentell untersucht. Der thermische Prozess wurde einerseits durch Benetzbarkeitsprüfungen und anderseites durch Rasterelektronmikroskopaufnahmen bewertet.Der Ultraschallprozess ist ein nasser Löschprozess. Die Untersuchungen wurden in vier Stufen systematisch durchgeführt - Auswahl vom geeigneten Lösungsmitteln - Einflüsse von ausgewählten Lösungsmitteln auf nicht beschichtete und beschichtete Aluminium platten - Evaluation eines Ultraschalllöschprozesses - Validation eines Löschprozesses; zur Bewertung des Löschprozesses wurden mehrere Druckplattenproben bebildert und gelöscht Die Ergebnisse wurden durch UV/Vis Spektrometer, Kontaktwinkel, Profiliometrie und Visuelle Mikroskopie getestet.
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Abd-el-Kader, Magdy Ezzat [Verfasser]. "Application of hot melt ink jet processes for imaging at offset printing form cylinder / vorgelegt von Magdy Ezzat Abd El Kader." 2004. http://d-nb.info/970645775/34.
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Trnovec, Bystrik. "Experimentelle Untersuchungen zur Schichtbildung im Tiefdruck mittels hydrophobierter Druckform mit Applikationsbeispielen aus dem Bereich der gedruckten OPV." Doctoral thesis, 2013. https://monarch.qucosa.de/id/qucosa%3A20554.
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Die vorliegende Arbeit beschreibt eine experimentelle Untersuchung der Schichtbildung von nichtnewtonschen Flüssigkeiten im Tiefdruckverfahren auf nicht saugfähigen Substraten. Das fluiddynamisch bedingte „viscous fingering“ beim Farbspaltungsprozess soll mittels Hydrophobieren der Druckform gehemmt werden. Ziel ist es, möglichst homogene sowie wellenfreie Schichten zu erzeugen. Um ein direkt miteinander vergleichbares Druckergebnis zu erhalten, wird der Druckstoff parallel mit einer unbehandelten und hydrophobierten Form bedruckt. Als Druckstoff werden anstelle von Druckfarbe funktionale Materialien (vorzugsweise PEDOT:PSS) verwendet und variiert, wobei die elektrischen und geometrischen Schichteigenschaften, beispielsweise der elektrische Widerstand und die Rauheit, zur Ermittlung der gesetzten Ziele untersucht wurden. Hiermit und mittels Nutzung einer hydrophobierten Druckform kann eine deutliche Minderung der Wellenbildung (viscous fingering) bei vielen Druckstoffarten beobachtet werden. Die Minderung des viscous fingering im Farbspaltungsprozess und eine nahezu vollständige Leerung der hydrophobierten Tiefdruckform haben einen wesentlichen Nutzwert für den künftigen Einsatz nicht nur für die „gedruckte Elektronik“.In this work is described experimental research about layer forming from non-Newtonian fluids in gravure printing on non-porous substrates. The viscous fingering, caused through fluid dynamics at splitting of printed material should be decreased by hydrophobic-surface modification of gravure printing form. The aim was to print wave-free homogenous layers. To achieve comparable results, modified and pure form were used simultaneously to print the same material. The printed material was mainly PEDOT:PSS and other, which is used in printed electronics. The properties (surface tension, viscosity) of printed materials were varied by additives. Printing conditions were varied too. The characteristic of printed layers were studied: resistivity, roughness, density, etc. The results shows decreasing of waviness, roughness and viscous fingering in final layer through use of hydrophobic gravure printing form, compared to print results with common printing form. This can be applied not only in the field of printed electronics.