Since the first discovery of an extrasolar planet around a solar-type star, observers have detected over 500 planets outside the solar system. Many of these planets have Jovian masses and orbit their host stars in orbits of only a few days, the so-called 'Hot Jupiters'. At such close proximity to their parent stars, strong tidal interactions between the two bodies are expected to cause significant secular spin-orbit evolution. This thesis tackles two problems regarding the tidal evolution of short-period extrasolar planets. In the first part, we adopt a simple model of the orbit-averaged effects of tidal friction, to study the tidal evolution of planets on inclined orbits. We also analyse the effects of stellar magnetic braking. We then discuss the implications of our results for the importance of Rossiter-Mclaughlin effect observations. In the second part, we study the mechanisms of tidal dissipation in solar-type stars. In particular, internal gravity waves are launched at the interface of the convection and radiation zones of such a star, by the tidal forcing of a short-period planet. The fate of these waves as they approach the centre of the star is studied, primarily using numerical simulations, in both two and three dimensions. We find that the waves undergo instability and break above a critical amplitude. A model for the tidal dissipation that results from this process is presented, and its validity is verified by numerical integrations of the linear tidal response, in an extensive set of stellar models. The dissipation is efficient, and varies by less than an order of magnitude between all solar-type stars, throughout their main-sequence lifetimes, for a given planetary orbit. The implications of this mechanism for the survival of short-period extrasolar planets is discussed, and we propose a possible explanation for the survival of all of the extrasolar planets currently observed in short-period orbits around F, G and K stars. We then perform a stability analysis of a standing internal gravity wave near the centre of a solar-type star, to understand the early stages of the wave breaking process in more detail, and to determine whether the waves are subject to weaker parametric instabilities, below the critical amplitude required for wave breaking. We discuss the relevance of our results to our explanation for the survival of short-period planets presented in the second part of this thesis. Finally, we propose an alternative mechanism of tidal dissipation, involving the gradual radiative damping of the waves. Based on a simple estimate, it appears that this occurs even for low mass planets. However, it is in conflict with current observations since it would threaten the survival of all planets in orbits shorter than 2 days. We discuss some hydrodynamic instabilities and magnetic stresses which may prevent this process.

An expansive panel of well exposed (periglacial) strata of the Upper Kaza Group permitted a detailed study of the stratal architecture of proximal basin floor deposits in the Neoproterozoic Windermere turbidite system. Detailed stratigraphic and petrographic analyses identified six lithofacies: poorly-sorted, clast-rich mudstone (F1), thin-bedded siltstone and mudstone (F2), thick-bedded, massive sandstone (F3), medium-scale, cross-stratified sandstone (F4), mudstone-clast breccia (F5), and medium-bedded turbidites (F6). The spatial distribution of these facies identify five architectural elements: heterolithic feeder channel deposits (FA1), thin-bedded intralobe turbidites (FA2), terminal splay deposits (FA3), distributary channel deposits (FA4), and isolated scours (FA5). FA 1-4 are genetically related and form the basic building blocks of large-scale basin floor depositional lobes. FA 5, which is isolated to the stratigraphic top of the study area, is interpreted to have formed in a base-of-slope setting, and its superposition on FA 1-4 suggests the long-term progradation of the Windermere turbidite system.

During the summer of 1968 a gravity survey was conducted over the Fox* Glacier, Yukon Territory, for the purpose of finding ice depths. Choice of the Fox Glacier was as a result of its predicted surge, and the survey was part of a long-term analysis of the physical condition of the glacier. Although seismic sounding was attempted, the thinness of the glacier prevented successful results. Analysis of the gravity measurements indicated 88m as the maximum depth; comparison with depths from three drilled holes showed that the gravity results were not seriously in error. A small near-surface temperature program was completed and the results identify the Fox as a sub-polar glacier. *This is not an officially accepted name. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The purpose of the study was to examine children's intuitive knowledge in the field of physical science, eliciting their theories of gravity and motion. Six grade seven children were interviewed across three tasks using a 'demonstration-interview' technique. The three tasks involved the motion of balls of different mass rolling down an inclined plane, falling freely in air, and falling in a water-filled tube. In each task, children were asked to predict and explain what would happen when one ball is 'let go', and when two balls of equal size but different mass were 'let go'. They were allowed to observe the phenomenon, and explain what they observed. Also, each child was asked to predict and explain what would happen when the experiment is done in a hypothetical situation on the moon, and in a space craft in outer space. The results of the study confirmed the commonly held ideas children maintain of gravity and motion, and yet illuminated some new connections between gravity and other factors. Having conducted the interviews across three tasks, a rich amount of information was revealed, and a variety of possible structures of children's conceptual frameworks of gravity and motion was deduced. The study revealed that children's prior knowledge has an impact on the acquisition of science concepts as taught through formal schooling. Their ideas persist in spite of the classroom schooling they receive. Therefore it is often necessary to restructure this prior knowledge before new knowledge can be properly incorporated into their conceptual frameworks. The study suggests that educators, as well as curriculum writers, need to re-examine the instructional methods and the role of inquiry in science education. / Education, Faculty of / Graduate

as one of three explanations of a prominenttine delay in the 6.5 km/s branch of their seismic refraction survey in the Rocky Mountain Trench, Eennett et al (1975) suggested a high-angle crustal fault crossing the trench near Radium. If the density contrast between basement and cover rocks is 0.1 g/cm3, a gravity anomaly of approximately 18 mgal should be observed. To test the fault hypothesis, a gravity survey has been carried out in and adjacent to the trench in the Radium area. The resultant data are not consistent with the proposed fault model. The principal feature of the data is a pronounced low which coincides with the trench throughout the survey area. The low is due to Cenozoic fill and interpretation by two-dimensional modeling indicates the thickness of fill is about 550 m to the north and 420 m to the south of Radium. An analysis has also been performed of the shear-wave data recorded during the seismic survey of Bennett et al (1975). Although the quality of the S save data is poor, they show consistent behavior with the P save data. There is weak evidence suggesting a basement refractor velocity of 3.5 km/s and a Moho refractor velocity of 4.2-4.5 km/s. The corresponding Poisscn's ratios are 0.30 and 0.28-0.32. To determine maximum and minimum depth limits to the Hcho allowed by the seismic data, an extremal analysis was performed on both the P and S wave record sections. From the P wave data, the limits on crustal thickness beneath the Rocky Mountain Trench are 52 km and 60 km; from the S wave data, the limits are 47 km and 59 km. Is a result of these additional studies, the tao alternative hypotheses of Bennett et al (1975) to explain the seismic data must be reconsidered. These are (1) the existence of a crustal low velocity zone and (2) a major deformation of the basement and overlying rocks due to the trench being an ancient zone of weakness which coincides with the western limit of the continental Precambrian craton. As reflections from the top of the low velocity zone are not observed by Bennett et al (1975), the second alternative is preferred. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第22243号 / 理博第4557号 / 新制||理||1654(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 川合 光, 教授 田中 貴浩, 教授 畑 浩之 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Electromagnetic levitation experiments provide a powerful tool that allows for the study of nucleation, solidification and growth in a containerless processing environment. Containerless processing allows for the study of reactive melts at elevated temperatures without chemical interactions or contamination from a container. Further, by removing the interface between the liquid and its container, this processing technique allows for greater access to the undercooled region for solidification studies. However, in these experiments it is important to understand the magnetohydrodynamic flow within the sample and the effects that this fluid flow has on the experiment. A recent solidification study found that aluminum-nickel alloy sample have an unusual response of the growth rate of the solid to changes in undercooling. This alloy experienced a decrease in the growth velocity as the initial undercooling deepened, instead of the expected increase in solidification velocity with deepening undercoolings. Current work is exploring several different theories to explain this phenomenon. Distinguishing among these theories requires a comprehensive understanding of the behavior of the internal fluid flow. Our project, USTIP, has done flow modeling to support this and multiple other collaborators on ISS-EML. The fluid flow models presented for the aluminum-nickel sample provide critical insights into the nature of the flow within the aluminum-nickel alloy experiments conducted in the ISS-EML facility. These models have found that for this sample the RNG k-ε model should be used with this sample at temperatures greater than 1800 K and the laminar flow model should be used at temperatures lower than 1600 K. Other work in the ISS-EML, has studied the thermophysical properties of liquid germanium and has found the most recent measurements using oscillating drop techniques to have a discrepancy from the expected property measurements taken terrestrially. Investigating this discrepancy required the quantification of the velocity and characterization of the internal fluid flow in the drop. The models have found that the flow within the sample maintains turbulent behavior throughout cooling. This thesis presents the analysis of the internal flow of four additional samples processed in the International Space Station Electromagnetic Levitation facility. These samples consist of the following alloys: Ti39.5Zr39.5Ni21, Cu50Zr50, Vitreloy 106, and Zr64Ni36. Our collaborators work required the internal flow to be characterized and quantified for their work on solidification. In addition to quantifying the velocity of the flow, the Reynolds number was calculated to characterize the flow during processing. Additionally, the shear-strain rate was calculated for the flow during processing up to the recalescence of the melt.

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The main objective of this master thesis is random equipartition concentration of measured gravimetric points in the area of interest pursuant by digital terrain model. Remove-Compute-Restore method was used for this purpose. In this thesis normal acceleration of gravity, topographic effect and Faye anomaly were subtracted from measured gravity. The result is Bouguer anomaly with general topographic effect which is interpolated for concentration points. We obtained predicated values of gravity after the restoration of subtracted effects. The main result of the thesis is the map of real gravity and precision evaluation of used method. Furthermore, the reductions of gravity, interpolation methods in programme ArcGIS, Remove-Compute-Restore method and the term of digital terrain model are explained in the thesis.

Particle deposition patterns formed in the lung upon inhalation are of interest to a wide spectrum of biomedical sciences, particularly for their influence on non-invasive therapies which deliver drugs to the respiratory track. Before reaching the alveoli, particles, or a collection of liquid droplets called aerosols, must transverse this bifurcating network. This dissertation proposes a multi-faceted strategy for optimizing current methods of drug delivery by analyzing particle deposition in a single bifurcation and a complex 3-dimensional tree as a model of the airways. In this thesis, previous probabilistic formulations of particle deposition in a single bifurcation were first examined, combined and verified by computational fluid dynamic modeling. The traditional single bifurcation model was then extended to a multigenerational network as a Markov chain. The probabilistic approach combined with detailed fluid mechanics in bifurcating structures, permits a more realistic treatment of particle deposition. The formulation enables a rapid comparative analysis among different flow policies, i.e. how varying modes of inhalation affect local particle deposition and total particle escape rates. For example, this approach showed that body position has a minimal effect on deposition pattern, while a specific flow profile maximize deposition into the periphery of the lung. Also included are novel experimental results of particle deposition. Most experimental deposition studies are restricted to total deposition. Regional deposition can only be estimated but not directly measured without the destruction of the lung like models. As a result, the measurement requires multiple models which adds to the variance. To this end a standard physical model for investigating effects of various ventilation strategies on regional particle deposition was developed. Results suggest that a brief pause in flow can increase deposition into regions of blocked airways where drugs would not otherwise enter. Experiments were also conducted to investigate the effects of inertia dominated flow in symmetric and asymmetric structures revealing novel features in 3D compared to 2D. This dissertation combines experimental and computation results to propose a strategy to efficiently move particles through a symmetric and asymmetric bifurcating structure. It also introduces possible strategies for maximizing deposition to a desired region of a lung structure.