Ink-jet deposition is an emerging technology that provides a more efficient, economic, scalable method of manufacturing than other traditional additive techniques by laying down droplets layer by layer to build up 3-D objects. The focus of this thesis is to investigate the material interface evolution during the droplet deposition process, which holds the key to understanding the material joining process. Droplet deposition is a complicated process and can be broken down into droplet impingement dynamics and droplet hardening. This research focuses on the study of the interface dynamics of droplet impingement. In order to study the interface dynamics, a novel metric is developed to quantify the evolving geometry of the droplet interface in both 2-D and 3-D for single and multiple droplets respectively, by measuring the similarity between the evolving droplet geometry and a desired shape. With the developed shape metric, the underlying physics of the interface evolution for single droplet impingement are examined with simulations using an experimentally validated numerical model. Results show that the Weber number determines the best achievable shape and its timing during the droplet impingement when Ohnesorge number is smaller than 1, while the Reynolds number is the determining factor when Ohnesorge number is larger than 1. A regime map is constructed with the results and an empirical splash criterion to guide the choice of process parameters for given fluid properties in order to achieve the best shape without splash for single droplet impingement. In order to study the interface dynamics for multiple droplet interaction, which is computationally prohibitive for commercial software packages, an efficient numerical model is developed based on the Lattice Boltzmann (LB) method. A new LB formulation equivalent to the phase-field model is developed with consistent boundary conditions through a multiscale analysis. The numerical model is validated by comparing its simulation results with that of commercial software COMSOL and experimental data. Results show our LB model not only has significant improvement of computational speed over COMSOL but is also more accurate. Finally, the developed numerical solver is used to study the interface evolution of multiple droplet interaction with the aid of the 3-D shape metric proposed before. Simulations are performed on a wide range of impingement conditions for two-droplet, a-line-of-droplet, and an-array-of-droplet interactions. The underlying physics of the interface coalescence and breakup coupling with the impingement dynamics are examined. For line-droplet interaction, the strategy for achieving the equilibrium shape in the shortest time is studied. An important issue is discovered for array-droplet interaction, which is the air bubble formation during the droplet interaction. The mechanism for the air bubble formation is investigated and the strategy to avoid this undesirable effect is also suggested. This thesis has largely reduced the gap between basic science of studying droplet impingement dynamics and engineering application in inkjet deposition and provided preliminary insights on the material joining process for additive manufacturing.

The effect of fabric structure and yarn-to-yarn liquid migration on the overall liquid transport behavior of fabrics is investigated in this research. Sorption of liquid from an unlimited reservoir as well as sorption of a limited quantity of liquid by fabrics representing different structural parameters is studied in detail. Sorption of a limited quantity of liquid is studied by performing drop spreading experiments on fabrics. The spreading and wicking of micron sized drops which are deposited on textile fabrics during ink jet printing is also studied. How the fabric structure related variables influence the spreading of ink drops and how exactly spreading influences printing quality is investigated in this research. Results showed that the wicking in fabrics is determined by the wicking rates of the yarns, thread spacing and more importantly by the rate at which liquid migrates from longitudinal to transverse threads and again from transverse threads back to longitudinal threads. Drop spreading rates were also determined by fabric structure. In general, compact and thinner fabrics showed highest drop spreading rates. Drop spreading rates are primarily affected by the manner and the rate at which liquid migrates from yarn to yarn. Analysis of the results of ink jet printing of pigment ink on textile fabrics showed that excessive drop spreading and higher line widths were observed where continuous and narrow capillaries prevail on the surface of yarns. Yarn surface characteristics are more important than fabric construction parameters.

Thesis (Ph.D.)--University of Melbourne, Dept. of Mathematics and Statistics, 2007. / Typescript. Includes bibliographical references (leaves 143-151).

Thèse (D.Eng.) -- Université du Québec à Chicoutimi, 2003. / Bibliogr.: f. [211]-216. Document électronique également accessible en format PDF. CaQCU

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2005. / Said I. Abdel-Khalik, Committee Chair ; Sheldon M. Jeter, Committee Member ; Minami Yoda, Committee Member. Includes bibliographical references.

Thesis (Ph.D.)--University of Delaware, 2007. / Principal faculty advisor: Kausik Sarkar, Dept. of Mechanical Engineering. Includes bibliographical references.

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Keratoconjunctivitis sicca (kCS) is a chronic inflammatory disease common in dogs, resulting from deficiency of the precorneal tear film. It can occur as a quantitative deficiency of the aqueous component of the tear, as well as a qualitative deficiency of the lipid or mucin components of the tear film, generating instability of that film. The ocular complications of this disease affect the ocular surface provoking vascularization, pigmentation and corneal edema. In more severe cases, it can also lead to loss of corneal epithelium, ocular pain and blindness. The treatment normally used for KCS is medicated and mainly includes tear, lacrimomimetics, mucolytics and topical antibacterials. Considering the importance of keratoconjunctivitis sicca, the objective of this study was to investigate and compare the treatment with different eye drops in healthy patients with KCS. For the study, a literature review on the KCS was carried out, addressing the main treatments (article 1), 13 dogs divided into two studies were used for the second study. The animals were divided into three groups of three animals each: in the CsA col group the treatment of the cornea was performed with cyclosporin A (0,05%) eye drops, Tacro group with tacrolimus eye drops (0,03%) and the CsA pom group with cyclosporin A ointment (0,05%). In the second study (article 3), the dogs were divided into two groups of two animals each, in the CsA col group collagen treatment was performed with cyclosporin A eye drops (0,05%) and the Tacro group with tacrolimus eye drops (0,03%). A drop of the medication was instilled every 12 hours in all animals and ophthalmic evaluations were performed on days 0, 15, 30, 45, 60, 75 and 90 days. Clinical signs of conjunctival hyperemia, type of present ocular secretion, corneal opacity, corneal vascularization and corneal pigmentation in healthy dogs and with KCS were evaluated through Schirmer's Lacrimal Test (TLS), Fluorescein Test, Rose Bengal Test. Based on the literature review on KCS, the best treatment described is tacrolimus eye drops. Among the surgical techniques, nasolacrimal duct occlusion was the best outcome. When analyzed the behavior of cyclosporin A in the formulation eye drops and ointment and tacrolimus in healthy animals, cyclosporin A in the ointment formulation was the one with the best lachrymal stimulation. In patients with CCS, when compared to treatments with CsA eye drops and tacrolimus, the dogs with tacrolimus were the most successful. / A ceratoconjuntivite seca (CCS) é uma doença inflamatória crônica comum em cães, resultante de deficiência do filme lacrimal pré-corneal. Pode ocorrer como uma deficiência quantitativa do componente aquoso da lágrima, bem como uma deficiência qualitativa dos componentes lipídico ou mucínico do filme lacrimal, gerando instabilidade desse filme. As complicações oculares dessa doença afetam a superfície ocular provocando vascularização, pigmentação e edema corneal. Em casos mais graves, pode ainda cursar com perda do epitélio da córnea, dor ocular e cegueira. O tratamento normalmente utilizado para CCS é medicamentoso e inclui principalmente lacrimogênicos, lacrimomiméticos, mucolíticos e antibacterianos tópicos. Considerando-se a importância da ceratoconjuntivite seca, o objetivo deste estudo foi investigar e comparar o tratamento com diferentes colírios em pacientes hígidos e com CCS. Para o estudo realizou-se inicialmente uma revisão bibliográfica sobre a CCS abordando os principais tratamentos (artigo 1), para a segunda pesquisa foram utilizados 13 cães divididos em dois trabalhos. O primeiro trabalho (artigo 2) os animais foram divididos em três grupos de três animais cada: no grupo CsA col o tratamento da córnea foi realizado com colírio de ciclosporina A (0,05%), o grupo Tacro com colírio tacrolimus (0,03%) e o grupo CsA pom com pomada de ciclosporina A (0,05%). No segundo trabalho (artigo 3), os cães foram divididos em dois grupos de dois animais cada, no grupo CsA col o tratamento da córnea foi realizado com colírio de ciclosporina A (0,05%) e o grupo Tacro com colírio tacrolimus (0,03%). Em todos os animais foi instilado uma gota da medicação a cada 12 horas e foram realizadas avaliações oftálmicas nos dias 0, 15, 30, 45, 60, 75 e 90 dias. As avaliações ocorreram através do Teste Lacrimal de Schirmer (TLS), Prova de Fluoresceína, Teste Rosa de Bengala, além dos sinais clínicos de hiperemia conjuntival, tipo de secreção ocular presente, opacidade corneal, vascularização corneal e pigmentação corneal em cães hígidos e com CCS. Com base na revisão bibliográfica sobre CCS, o melhor tratamento descrito é o colírio de tacrolimus, entre as técnicas cirúrgicas a que obteve melhor resultado foi a oclusão do ducto nasolacrimal. Quando analisado o comportamento da ciclosporina A na formulação colírio e pomada e o tacrolimus em animais hígidos, a que apresentou melhor estimulação lacrimal foi a ciclosporina A na formulação de pomada. Em paciente com CCS, quando comparados os tratamentos com CsA colírio e o tacrolimus, os que obtiveram melhor resultado foram os cães tratados com tacrolimus.

Ce travail vise à améliorer la compréhension des mécanismes particuliers du séchage des matériaux céramiques. Cette étape est cruciale lors de la création d’une pièce. En effet, outre l’optimisation de la composition de l’échantillon, la température ainsi que l’humidité relative doivent être contrôlées afin que la perte de masse et le retrait n’entraînent pas l’apparition de contraintes pouvant mener à la création de fissures qui, suite à un traitement thermique, endommageront la pièce finale. Dans un premier temps et après une présentation des différents mécanismes connus du séchage, cette thèse met en avant un ensemble de montages conçus au sein d’une enceinte climatique instrumentée. À l’aide de ces derniers,une première étude portant sur le comportement en température et en humidité du liquide de façonnage seul est réalisée. Ce liquide a ensuite été introduit entre deux substrats identiques et parallèles pour reproduire le cas d’un ménisque au sein d’une porosité. Les contacts hydrophiles et hydrophobes ont alors été étudiés. Enfin, des expériences de séchage ont été menées sur des matériaux céramiques afin de corréler les différentes observations. Les résultats obtenus démontrent l’importance d’un compromis dans le choix des paramètres de séchage. La température et l’humidité relative influencent non seulement la cinétique du procédé lors du départ de l’eau, mais modifient également le contact avec la phase solide de la pièce céramique. En fin de séchage, la rupture des ponts liquides est brutale et peut expliquer certains phénomènes macroscopiques observés lors du séchage de pièces de tailles industrielles. / This work aims at improving the understanding of the specific mechanisms of the drying of ceramic materials. This step is crucial when manufacturing a piece. Indeed, besides the optimization of the sample composition, the temperature and the relative humidity have to be controlled so that the weight loss andthe shrinkage do not cause any stress development, leading to cracks formation which can damage the final piece after a heat treatment. After a presentation of the different known drying mechanisms, this thesis highlights a set of measuring benches conceived within an instrumented climatic chamber. A firststudy concerning the behavior of the shaping liquid as a function of temperature and relative humidity isrealized. Then, this liquid is inserted between two parallel and identical substrates in order to reproduce the case of a liquid bridge within a pore. The hydrophilic and hydrophobic contacts are then studied.Finally, drying experiences are carried out on ceramic materials to correlate the different observations.The obtained results demonstrate the importance of a compromise when selecting the drying parameters.The temperature and the relative humidity not only influence the kinetics of the process during the liquiddeparture, but also modify the contact with the solid phase of the ceramic piece. At the end of drying, the rupture of liquid bridges is brutal and can explain some macroscopic phenomena observed when dryinglarge pieces.

First we define microscopic sets on the real axis and study their relation to the sets of Hausdorff and Lebesgue measure zero and the sets of first category. In the second part, we prove the Bishop-Phelps' theorem and its equivalence with the Ekeland's variational principle, the Daneš's drop theorem, the Brézis-Browder's theorem and the Caristi-Kirks's theorem. Doing so we define the notion of a drop as the convex hull of a set and a point. In the third part we prove that the drop property equals reflexivity in some sense. A space has the drop property if it is possible to find the drop from the Daneš's theorem even in a more general case than the theorem itself guarantees. Furthermore, we characterize this property using the approximative compactness. Last, we study the microscopic drop property that is more relaxed than the original drop property. We find out that those two notions are for noncompact sets in reflexive spaces equivalent. Powered by TCPDF (www.tcpdf.org)

Doctor of Philosophy / Department of Animal Sciences and Industry / Jim L. Nelssen / The overall objective of these experiments was to develop management and feeding programs to increase sow longevity and productivity by improving welfare conditions. In Exp. 1, 208 gestating sows and 288 gestating gilts were utilized to determine the effect of feeding frequency (2 vs. 6) on performance and welfare issues. Feeding frequency had no affect on growth and reproductive performance in gestating sows; however, increasing the feeding frequency did improve the welfare measurements in this trial. Gilts fed six times a day did have increase ADG during d 0 to 42; however, there was no affect on performance from d 42 to farrowing. In Exp. 2 (630 pigs in 4 studies), increasing the feeding frequency (2 vs. 6) of a restricted feeding level increased growth performance of finishing pigs. This affect is likely due to the increase of available energy above maintenance when compared with the gestating sows. In Exp. 3, different feed drops used for delivering feed were evaluated. The Accu and the Ultra feed drops were more accurate than the Econo feed drop at angles of 90, 75, and 60°. The difference in accuracy is potentially related to the way that the drops attach to the feed line. However, the amount of feed that is collected in each drop appears to increase linearly as the feeder settings are increased. Thus, regression equations for the angle of the feed drop can be developed to adjust for the variability in the amount of accumulated feed. In Exp. 4, Alimet® was used to determine the TID TSAA:Lys ratio for ADG and G:F of 63 and 66% for Genetiporc and 61 and 56% for PIC pigs weighing between 10 to 20 kg. In Exp. 5, the optimal TID Lys:Calorie ratio was estimated to be 3.7 and 4.1 g Lys/Mcal ME for the Genetiporc and PIC pigs weighing between 10 to 20 kg . The ratios were than validated at two energy levels and the amount of TID Lys that was used for lean gain was similar for both genetic lines at approximately 20 g of Lys for each kg of gain.