One of the basic goals in engineering is to generate models which will provide a means for analytically predicting observed phenomenon. Such a model is often modified several times to obtain better results. The purpose of this study was to generate a model for an equilibrium turbulent boundary layer for steady flow over a flat plate and compare the results obtained by using the model with experimental data. Part of the objective was to also suggest ways in which the model could be modified to obtain better results.

The thin interface separating the inner turbulent region from the outer irrotational fluid is analyzed in a direct numerical simulation of a spatially developing turbulent mixing layer. A vorticity threshold is defined to detect the interface separating the turbulent from the non-turbulent regions of the flow, and to calculate statistics conditioned on the distance from this interface. Velocity and passive scalar statistics are computed and compared to the results of studies addressing other shear flows, such as turbulent jets and wakes. The conditional statistics for velocity are in remarkable agreement with the results for other types of free shear flow available in the literature. In addition, a detailed analysis of the passive scalar field (with Sc 1) in the vicinity of the interface is presented. The scalar has a jump at the interface, even stronger than that observed for velocity. The strong jump for the scalar has been observed before in the case of high Schmidt number, but it is a new result for Schmidt number of order one. Finally, the dissipation for the kinetic energy and the scalar are presented. While the kinetic energy dissipation has its maximum far from the interface, the scalar dissipation is characterized by a strong peak very close to the interface.

ABSTRACT The belief that herbal remedies are less invasive on the human body than conventional medicine and the return of the consumer to a more natural lifestyle, has led to the development of a multitude of remedies, with many different uses. Because the use of these herbal remedies has increased drastically in the last decade, it is essential that the quality and efficacy of these products are well regulated. One of the objectives in this study includes the investigation of the presence of marker metabolites in five herbal remedies, namely Serenoa repens, Silybum marianum, Hypericum perforatum, Echinacea purpurea and Gingko biloba. Although most of the brands tested contained the active ingredients assayed for, a few exceptions were found. However, because this study used only thin layer chromatography for analysis of products, verification of these results should be obtained using other more modern methods for example high pressure liquid chromatography. Four brands of Serenoa repens were selected and assayed for the presence of -sitosterol. All four brands tested indicated the presence of -sitosterol. Five brands of Hypericum perforatum were selected and assayed for the presence of hypericin, rutin and chlorogenic acid. Four of the five products tested indicated the presence of hypericin, while three of five products indicated the presence of rutin and chlorogenic acid. Five brands of Echinacea purpurea were selected and assayed for the presence of -sitosterol, chlorogenic and caffeic acid. Three of the five products indicated the presence of -sitosterol, while only one of the five products contained chlorogenic acid. Caffeic acid was present in 3 of the 5 products. Seven brands of Gingko biloba were selected and assayed for the presence of rutin and bilobalide. Five of the seven products indicated the presence of rutin and bilobalide. Four brands of Silybum marianum were selected and assayed for the presence of both taxifolin and sylibin. Only two of the four products contained both taxifolin and silybin. The second objective of this study is to provide a literature review of the five herbal remedies mentioned above. Amongst the topics discussed were uses of these plants, evidence from studies conducted, chemistry and mechanism of action of the active molecules contained in the plants.

Mycoplasma gallisepticum (MG) is a bacterium that causes egg production losses in layer chickens raised on multi-age layer hen complexes. To combat this loss, layer chickens are vaccinated against MG before they are moved to the layer facility to begin laying eggs. The objective of this dissertation research was to investigate the potential of the in ovo vaccination of layer chickens against field strain MG infections to enhance immunity, and reduce labor and material costs associated with the current post-hatch vaccination method. Initial studies tested various dosages of a live attenuated strain F (FMG) vaccine delivered in ovo by hand injection at 18 days of incubation. The greatest dilution of vaccine (1-3 colony forming units (CFU) per dose) did not have an adverse effect on hatch success and was able to induce initial antibody production against FMG in approximately 50% of the birds raised through 6 weeks of age, with relatively low post-hatch mortality. Higher dosages tested, starting at 102 CFU per dose, caused extremely high (>50%) post-hatch mortality during the first 2 weeks and were considered impractical. These in ovo-vaccinated birds, even at the lowest FMG dose, were able to transmit the bacteria to other MG-clean birds with which they were in direct contact. The lowest in ovo FMG dose was further tested for its ability to be applied using a current in ovo vaccination machine. This machine externally disinfects each injection needle after every injection. The FMG was detected in FMG-vaccinated birds at 6 weeks of age whether or not they had received the disinfection step. Furthermore, birds hatched from eggs that were injected with and without disinfection had comparable humoral immune responses against FMG, with similar results to the hand injection study. Thus, the disinfection step during in ovo vaccination caused no loss of FMG vaccine efficiency and the in ovo vaccination of layer chickens against FMG could be readily practiced in the poultry industry. Future work should evaluate how this in ovo vaccination regimen compares with other post-hatch MG vaccination regimens for layer chickens through the lay cycle and against a field strain MG challenge.

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With the growing impact of climate change on both political decisions and how companies develop their products, it is increasingly important to find environmentally friendly alternatives to fossil-based materials. One of the more interesting materials in this respect is cellulose, which is the world's most naturally occurring polymer and can be used in a variety of applications. One way to modify the fibers and to change their properties is to use a method called Layer-by-Layer (LbL) treatment where two polymers of opposite charge are alternately adsorbed to the fiber surface. Another possibility is to oxidize the cellulose in the fibers to obtain a higher charge. This means that the fibers can adsorb a higher amount of cationic additives and that the fibers swell more which means that they are plasticized and can create stronger joints between the fiber surfaces in the dry state, which results in stronger dry fiber networks. However, wood-based fibers are small and inhomogeneous, both chemically and morphologically, which means that it is necessary to use model systems to be able to clarify, in detail, how treated and untreated surfaces interact with each other at a molecular level. One model system that can be used to investigate how cellulose fibers are affected by coating using the LbL method is to use spherical beads made from regenerated cellulose. In the present work, these beads were treated with polyallylamine hydrochloride (PAH) and hylauronic acid (HA) as well as with PAH and alginate (Alg) before being allowed to dry together and then subjected to tensile testing to clarify the adhesion between the surfaces. The beads were treated with five and ten bi-layers of these polymers, respectively, and then dried together on an AKD-coated surface, to avoid adhesion to the underlying surface, to examine the adhesion between the beads. The adhesion increased when treated with LbL and became higher upon adsorption of multiple layers of polyelectrolytes and the Alg / PAH system showed the greatest increase. Ten-layer samples of Alg / PAH were also tested after a solution of calcium chloride was added during drying, resulting in poorer adhesion between the beads. / Med klimatfrågans växande inverkan på både politiska beslut och hur företagen utvecklar sina produkter så läggs det allt större vikt vid att hitta miljövänliga alternativ till fossilbaserade material. Ett av de mer intressanta materialen är cellulosa vilket är världens mest naturligt förekommande polymer och som kan användas i en rad olika tillämpningar. Ett sätt att modifiera fibrerna och att ändra deras egenskaper är att använda sig av en metod som kalls Layer-by-layer (LbL) behandling där två polymerer mot motsatt laddning växelvis adsorberas till fiberytan. En annan möjlighet är att oxidera cellulosan i fibrerna så att de erhåller de en högre laddning. Detta innebär dels att fibrerna kan adsorbera en högre mängd katjoniska tillsatskemikalier samt att fibrerna sväller mera vilket innebär att de plasticeras och kan skapa starkare fogar mellan fiberytorna i torrt tillstånd vilket resulterar i starkare torra fibernätverk. Vedbaserade fibrer är dock små och inhomogena såväl kemiskt som morfologiskt vilket innebär att det är nödvändigt att använda modellsystem för att kunna klarlägga, i detalj, hur behandlade och icke behandlade ytor växelverkar med varandra på en molekylär nivå. Ett modellsystem som kan användas för att undersöka hur cellulosafibrer påverkas av att beläggas med hjälp av LbL metoden är att använda sig av sfäriska kulor tillverkade från regenererad cellulosa. I föreliggande arbete behandlades dessa kulor med polyallylaminhydroklorid (PAH) och hylauronsyra (HA) samt med PAH och alginat (Alg) innan de tilläts torka ihop och därefter utsattes för dragprovning för att klarlägga adhesionen mellan ytorna. Kulorna behandlades med fem respektive tio bilager av dessa polymerer och torkades sedan ihop på en AKD-belagd yta, för att undvika adhesion till den underliggande ytan, för att undersöka adhesionen mellan kulorna. Adhesionen ökade när de behandlades med LbL och blev högre vid adsorption av flera lager polyelektrolyter och systemet med Alg/PAH resulterade i den största ökningen. Prover med tio lager av Alg/PAH testades även efter att en lösning av kalciumklorid tillsattes under torkningen vilket resulterade i en sämre adhesion mellan kulorna.

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