Surface gravity waves and internal waves are two of the most common natural phenomena in the ocean. While oceanographers believe that internal waves have greater influence over the surface waves, if is not clear to what extent that the former have affected the latter. As an internal wave propagating in the ocean, short period flow could be induced on the free surface layer. Moreover, as internal waves propagating over a submarine ridge, internal breaking accompanying by large vortex may have occurred, which may also affect the properties of the surface waves. To prove the relationship between them, basic mathematical equations have been derived, but had never been proven in the laboratory experiments or field observations. In this thesis, the results of a series of laboratory experiments conducted at the National Sun Yen-sen University are employed to study the waveform evolution and change to the physical parameters of the surface waves, resulting from the generation of internal waves induced on a stratified fluid, as both propagate together above a plane bottom or across single ridge. These experiments were carried out in a stratified two-layer fresh/brine water system (upper layer with fresh water density 996 kg / m3; bottom layer brine water with 1030 kg / m3) in a steel framed wave tank of 12m long with cross-section of 0.7 m high by 0.5 m wide. A plunging-type wave maker was used to produce the designated surface waves, from which the internal waves were induced at the interface. Based on the experimental results in the fluid system with uniform density, wave height and period of the surface wave were first calibrated. It was found that the amplitude of a surface wave decreased first due to the breaking of the internal wave on the apex of a submerged ridge and then increased due to wave regeneration at the back of the ridge, when the surface wave propagated over single ridge. Beyond the ridge, the peak period with maximum energy associated with the transmitted wave remained almost the same with that of the incident waves. In a stratified fluid system, wave height of the surface waves and internal waves did not suffer much change but the peak period of a surface wave increased as an internal wave just across the apex of the obstacle, under a condition referred to as weaken interaction between the waves and the obstacle. For the intense wave breaking condition at the interface, wave height of the internal waves decreased and the period of surface waves or internal waves shortened. However, wave height of the surface wave above the apex of the obstacle increased due to the intense wave breaking. The results obtained from the present laboratory experiments on the interaction between a surface wave and the induced internal wave could benefit others interested in surface and internal wave interaction for practical applications in oceanography or numerical modeling.

L'ensemble des interactions entre particules est à ce jour décrit dans un modèle appelé Modèle Standard. Celui-ci sera brièvement décrit dans le premier chapitre de ce manuscrit. Cependant, il apparait que ce n'est pas un modèle complet capable de tout expliquer ce que l'on observe à l'échelle de l'infiniment petit et d'unifier l'ensemble des couplages à grande énergie. C'est pourquoi de nombreuses théories ont vu le jour, avec plus ou moins de succès, dans l'espoir d'avoir une théorie du "tout". Parmis ces modèles, beaucoup prédisent l'existence de particules ayant certaines propriétés, on les appelle Leptoquarks. <br />Ce manuscrit présente une analyse pour la recherche de telles particules aboutissant finalement non pas a une decouverte mais a une limite d'existence en fonction de leur masse. Cette analyse a été effectuée à partir de données collectées auprès du détecteur D0 situé à un des points autour de l'accélérateur TeVatron à Fermilab, près de Chicago. Le cadre expérimental de cette expérience sera décrit dans le second chapitre. Ce manuscrit présente également la contribution que j'ai eu auprès de la collaboration de D0 pour la calibration du calorimètre électromagnétique.

<p>This paper examines the prevalence and character of age discrimination by conducting and experiment with 200 students at Växjö University. The participants were first asked to read a description of a job of either youthful or age neutral character. Afterwards they got to evaluate one out of two job applicants. The applicants were made identical in every way with the exception of age, in order to isolate the age discrimination. The results for the different jobs and applicants were then compared in order to investigate the prevalence of discrimination. The results support the hypothesis that age discrimination exists. In order to examine the dominance of either taste discrimination or statistical discrimination, i.e. whether the discrimination is the result of personal preferences or stereotypes and statistical mean values of different age groups the results were studied more in depth. The results hint a dominance of statistical discrimination over taste discrimination.</p>

Thesis (Ph. D.)--Swedish University of Agricultural Sciences, 2000. / Includes bibliographical references (p. 393-402) and index.

Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. James R. Simpson, Florida State University, College of Engineering, Dept. of Industrial and Manufacturing Engineering. Title and description from dissertation home page (viewed Mar. 2, 2004). Includes bibliographical references.

Increasing atmospheric carbon dioxide (CO₂) leads to global warming. This can have several impacts on climate and on plant biodiversity, and has been the topic of many studies. The objective of this thesis was to understand the effects of higher atmospheric CO₂ on soil moisture dynamics in the grasslands of central Minnesota using detailed hydrologic modeling to explain previous experimental observations at the BioCON site, a free-air CO₂ enrichment experiment. The hydraulic properties and texture of soils collected from BioCON were determined in the laboratory through grainsize analysis and continuous evaporative drying to determine soil moisture retention curves and hydraulic conductivities. These results were used as input for numerical soil water flow and energy balance models. The models showed that vegetation presence and atmospheric CO₂ concentrations significantly affected the soil moisture dynamics. Summer evapotranspiration (ET) had a higher variation for bare plots than for vegetated plots. This likely occurred because the vegetation provided a buffer against the variations in weather conditions. Vegetation not only retains part of the precipitation on its leaves, it also retains water in its structure and transpires while carrying out photosynthesis. Higher water content was also seen for the bare plots than for the vegetated soils. For some vegetated plots, there were differences between simulated and observed soil moisture. This could have been caused by a difference in plant composition and could suggest that different plant species can respond differently to varying CO₂ atmospheric concentrations leading to different soil moisture dynamics. In addition to this, smaller ET values and higher soil water content values at vegetated elevated CO₂ conditions than at ambient CO₂ conditions were simulated. This was expected, as higher atmospheric CO₂ is linked to higher plant water efficiency and larger biomass. For the simulations, higher values for stomatal resistance and higher plant and plant residue biomass were used. If increasing CO₂ conditions in fact decreases ET, regional weather patterns could be affected as less ET could delay the speed that water flows through the water cycle. / text

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.