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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
261

A study of the school for apprentices of the Lakeside press.

Davis, Carl Dewitt. January 1922 (has links)
Thesis (M.A.)--Univ. of Chicago, 1921.
262

William Caxton and the labor of literature in fifteenth century England

Tonry, Kathleen Ann. January 2005 (has links)
Thesis (Ph. D.)--University of Notre Dame, 2005. / Thesis directed by Maura B. Nolan and Graham L. Hammill for the Department of English. "April 2005." Includes bibliographical references (leaves 165-177).
263

Men's stereotypes of women in management are women aware of how they are stereotyped? /

Crawford, Kevin Charles. January 2006 (has links) (PDF)
Thesis (M.S.)--Montana State University--Bozeman, 2006. / Typescript. Chairperson, Graduate Committee: Richard A. Cook. Includes bibliographical references (leaves [22]-[24]).
264

Gloss Development of Spray-coated Systems

Clark, Aaron W. January 2004 (has links) (PDF)
No description available.
265

Jan Tschichold : contrast in theory /

Hannigan, Thérèse M. Tschichold, Jan, January 1992 (has links)
Thesis (M.S.)--Rochester Institute of Technology, 1992. / Typescript. Contains a catalog of the author's graduate thesis exhibit of Tschichold's work located in the Melbert B. Cary, Jr. Graphic Arts Collection, Rochester Institute of Technology, Rochester, N.Y., Dec. 7, 1992-Jan. 15, 1993. Includes bibliographical references.
266

Carbon nanotubes as a material for functional inks

Graddage, Neil January 2012 (has links)
Carbon nanotubes (CNTs) have been proposed as a material for use in printed electronics for a number of years. The potential to exploit the unique electrical and mechanical properties of these structures on the macro-scale is appealing; however there are a number of hurdles to overcome. Printing allows the deposition of CNT networks, the properties of which are governed by the CNT type and network density. The formulation of a suitable ink and deposition of a film with specific properties is challenging, and the work described in this thesis is concentrated on two specific areas, CNT ink development and CNT based device production. The CNT ink was developed by identifying key ink and dried film parameters for characterisation and assessing the effect of several major variables, namely the resin material, resin concentration, processing temperature, CNT concentration, CNT functionality and processing energy. A suitable research ink was developed and optimised using N-methyl-2-pyrrolidone as the solvent and polyvinyl alcohol as the resin at a concentration ratio of 1:1 with the CNT content. The effects of CNT concentration, CNT functionality and processing energy are shown to be interdependent. This is among the first reported studies to investigate the dependence of these factors upon a CNT ink for roll-to-roll processing. This ink system was then used in the production of CNT based thin film transistor (TFT) devices using flexography. Initially the concept was proven using MWCNTs. The design was then refined and devices were produced using SWCNTs at varying network densities. It was seen that the printing of CNT based devices using flexography is feasible, though careful control of the CNT network density is required to achieve suitable device performance. This is the first reported production of TFTs using flexography, and the first reported use of flexograi)hy to deposit CNTs.
267

Fluid characterisation and drop impact in inkjet printing for organic semiconductor devices

Jung, Sungjune January 2011 (has links)
An inkjet printer can deposit a very small volume of liquid with high positional accuracy, high speed and low cost. As a maskless, non-contact additive patterning method, inkjet printing technology is increasingly being explored as an alternative to lithography, etching and vapour deposition processes to pattern electrical conductors and thin films with applications in printed electronic devices. The functional inks used in many of the applications involve non-linear viscoelasticity and their behaviours in the context of inkjet printing have not been fully understood. This thesis aims to characterise Newtonian and non-Newtonian properties of inkjet fluids and identify the key parameters affecting drop impact and spreading processes. Various fluid characterisation techniques such as the filament stretching rheometer and piezoelectric axial vibrator are explored. We propose an experimental method to assess the jettability of non-Newtonian inkjet fluids, without using an inkjet print head. The oblique collision of two continuous liquid jets leads to the formation of a thin oval liquid sheet bounded by a thicker rim which disintegrates into ligaments and droplets. Under certain conditions the flow structure exhibits a remarkably symmetrical 'fishbone' pattern composed of a regular succession of longitudinal ligaments and droplets. Good correlation was found between the maximum included angle of the fishbone pattern and the maximum ligament length in the jetting experiments, which suggests that a test based on oblique impinging jets may be useful in the development of fluids for ink jet printing. High-speed imaging is used to analyse the impact and spreading of sub-30 μm drops of diethyl phthalate or polystyrene solutions in diethyl phthalate on to smooth glass surfaces with controlled wettability at speeds from 3 to 8 m s-1, under conditions representative of drop-on-demand inkjet printing. Data on drop height and spreading diameter are generated with high time and spatial resolution, over eight orders of magnitude in timescale. The effects of fluid viscosity and elasticity, which significantly affect jetting performance, are negligible throughout the whole deposition process, with no significant difference between spreading curves. The values of the fluid surface tension and the substrate wettability also have no effect on the kinematic, spreading or relaxation phases, but a marked influence on the wetting phase, in terms of the speed of expansion of the contact diameter and the final spreading factor.
268

3D printing of gold nanoparticles

Posluk, Patrick January 2020 (has links)
and the placement of the material. Hence, 3D printing can be an advantageous new method of constructing supercapacitors.In this thesis, the aim was to investigate how the different parameters of Electrohydrodynamic printing (EHD printing) will affect the spread of gold nanoparticles. The electrohydrodynamic printing method is a printing method that utilizes an electric field to cause droplet ejection from the nozzle. When the electric field exerts a force on the solution containing nanoparticles, it stretches the meniscus to a point where it becomes unstable and forms a droplet. EHD printing utilizes an electric field which gives the method a high spatial accuracy while being able to print droplets with within a separation distance of tens of nanometers.Different parameters were evaluated to achieve desired distribution of gold nanoparticles across a silicon wafer substrate. This thesis focuses on print speed, frequency, heat treatment and voltage, and how printing parameters affect the results. The results revealed a variation, while the printing patterns follow a trend. The best results achieved in this work came from a low nozzle-substrate voltage, high frequency, and high printing speed. The varying results could be brought on by variation in ink composition, the nozzle diameter, and the metal coating of the capillary, to name a few possible causes.Handledare:
269

Topology Optimization of 3D Printed Flexural Elements

January 2020 (has links)
abstract: Investigation into research literature was conducted in order to understand the impacts of traditional concrete construction and explore recent advancements in 3D printing technologies and methodologies. The research project focuses on the relationship between computer modeling, testing, and verification to reduce concrete usage in flexural elements. The project features small-scale and large-scale printing applications modelled by finite element analysis software and printed for laboratory testing. The laboratory testing included mortar cylinder testing, digital image correlation (DIC), and four pointbending tests. Results demonstrated comparable performance between casted, printed solid, and printed optimized flexural elements. Results additionally mimicked finite element models regarding failure regions. / Dissertation/Thesis / Masters Thesis Engineering 2020
270

Generation of emulsion droplets and micro-bubbles in microfluidic devices

Zhang, Jiaming 04 1900 (has links)
Droplet-based microfluidic devices have become a preferred versatile platform for various fields in physics, chemistry and biology to manipulate small amounts of liquid samples. In addition to microdroplets, microbubbles are also needed for various pro- cesses in the food, healthcare and cosmetic industries. Polydimethylsiloxane (PDMS) soft lithography, the mainstay for fabricating microfluidic devices, usually requires the usage of expensive apparatus and a complex manufacturing procedure. In ad- dition, current methods have the limited capabilities for fabrication of microfluidic devices within three dimensional (3D) structures. Novel methods for fabrication of droplet-based microfluidic devices for the generation microdroplets and microbubbles are therefore of great interest in current research. In this thesis, we have developed several simple, rapid and low-cost methods for fabrication of microfluidic devices, especially for generation of microdroplets and mi- crobubbles. We first report an inexpensive full-glass microfluidic devices with as- sembly of glass capillaries, for generating monodisperse multiple emulsions. Different types of devices have been designed and tested and the experimental results demon- strated the robust capability of preparing monodisperse single, double, triple and multi-component emulsions. Second, we propose a similar full-glass device for generation of microbubbles, but with assembly of a much smaller nozzle of a glass capillary. Highly monodisperse microbubbles with diameter range from 3.5 to 60 microns have been successfully produced, at rates up to 40 kHz. A simple scaling law based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. Recently, the emergent 3D printing technology provides an attractive fabrication technique, due to its simplicity and low cost. A handful of studies have already demonstrated droplet production through 3D-printed microfluidic devices. However, two-dimensional (2D) flow structures are still used and the advantage of 3D-printing technique has not been fully exploited. Therefore, we apply 3D printing technology to fabricate 3D-miniaturized fluidic device for droplet generation (single emulsion) and droplet-in-droplet (double emulsion) without the need for surface wettability treat- ment of the channel walls, by utilizing 3D geometry design and fabrication. A scaling law is formulated to predict the drop size generated in the device. Furthermore, magnetically responsive microspheres are also produced with our emulsion templates, demonstrating the potential applications of this 3D emulsion generator in chemical and material engineering. Finally, we design and 3D-print a hybrid ?plug-and-play? microfluidic droplet generator, which involves a 3D-printed channel chamber and commercial tubings and fittings. By combination of 3D-printed part and market-available parts, this device can be easily assembled and disassembled, which provides a great flexibility for different demands. A scaling law has been proposed for prediction of drop size generated in the device. Furthermore, a 3D-printed concentration gradient generator and a droplet merging device based on the droplet generator have been developed to demonstrate the great scalability of 3D-printing technology.

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