Physical Sciences and Mathematics Commons^™

Collision Spectroscopy Of Low Energy Capture By Multiply Charged Ions From Atomic Targets, Kadir Akgungor

Dissertations

State-selective differential cross sections for single-electron capture processes in very slow collisions of Ar^q+ (q = 4 - 6) ions with Ne, and Ar^6+ ions with He have been studied experimentally at laboratory collision energies between 15 and 100 qeV, and at scattering angles between 0° and 8° by means of translational energy-gain spectroscopy technique. The translational energy spectra show that only a few final states are populated depending on the charge state of the projectile, the projectile laboratory scattering angle, and the collision energy. These measurements also show that the dominant reaction channels are due to capture into excited …

Systematics Of Stable Isotopes And Radionuclides In Precipitation At Kalamazoo, Michigan, Usa, Madhav V. Machavaram

Dissertations

Precipitation samples were collected at Kalamazoo from June 1992 to March 1995. The samples were analyzed for their 8D and 8lgO values. The 5D - 5I80 relationship is comparable to that of Meteoric Water Line (MWL). The monthly mean isotopic values in precipitation exhibited strong seasonality, being higher in summer and lower in winter months. This behavior is apparently a direct consequence of the temperature effect on isotope fractionation.

The summer precipitation at Kalamazoo is derived predominantly from the water vapor originated in the Gulf of Mexico. A box model calculation showed that a Rayleigh type distillation with Gulf moisture …

Bandwidth, Edgesum And Profile Of Graphs, Yung-Ling Lai

Dissertations

No abstract provided.

Domination In Digraphs, Lisa Hansen

Dissertations

No abstract provided.

A Robust Estimate For An Autoregressive Time Series, Jeffrey Terpstra

Dissertations

A weighted rank-based estimate for estimating the parameter of an auto-regressive time series is considered. When the weights are constant, the estimate is equivalent to using Jaeckel’s estimate and Wilcoxon scores. The estimate can be shown to be asymptotically normal at rate y/n. In a linear regression setting this estimate has the desired properties of a continuous totally bounded influence function and a positive breakdown point. It is shown via examples and Monte Carlo that these properties are preserved in an autoregressive time series setting.

Localization And Transport Effects In The Disordered Materials, Vladislav Malyshkin

Dissertations

No abstract provided.

Groundwater-Kalamazoo River Interaction Near The Parchment City Wellfield, Parchment, Michigan, W. Richard Laton

Dissertations

A detailed hydrogeologic study of the Kalamazoo River and its interaction with the groundwater was completed near Parchment, Michigan. The Kalamazoo River between Portage Creek and Allegan Dam is a Federal superfund site due to PCB contamination trapped in its sediments. The City of Parchment pumps all of its drinking water from a glacial aquifer 850 feet from the Kalamazoo River. This study focused on the hydrogeology and groundwater/surface interaction of the area through the use of surface and downhole geophysics, installation of monitoring wells and peizometers, seepage meters and chemical sampling. It was determined that the Kalamazoo River is …

Reconstruction Of Wetland Hydrology Dynamics Using Tree Rings, Allan P. Hascall Iii

Dissertations

Increment core samples were collected and examined to test the hypothesis that the history of punctuated or intermediate-term changes in wetland soil-moisture conditions can be reconstructed from the annual growth-ring record of trees. The hypothesis is based on plant physiological principles that indicate a relationship between water surplus stress and impaired physiological activity that could lead to reduced growth.

Sampling sites were selected for their ostensible historic hydrologic variability and the availability of documentation of hydrologic disturbances. A conceptual model was developed by which trees were sampled along a hydrotopographic gradient for comparison of radial stem growth in uplands versus …

Study Of Impurity Modes In Photonic Crystals And Study Of Power Gaas Mesfets, Michael G. Khazhinsky

Dissertations

The dissertation consists of two projects. In the first project, impurity modes in Photonic Crystals are studied in one- and two-dimensional Photonic Crystals. Onedimensional systems are formed from an infinite layered array of dielectric slabs and are studied for linearly polarized electromagnetic waves propagating perpendicular to the plane of slabs. Two-dimensional systems consist either of parallel cylindrical dielectric rods in vacuum or cylindrical holes containing vacuum in dielectric medium. These rods/holes are arranged in a square lattice array. The electromagnetic waves in these system propagate perpendicular to the axes of the rods and are of E or H polarization. Green’s …