Physical Sciences and Mathematics Commons^™

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- Southwestern Tablelands, D. C. Gosselin, J. Headrick, X- H. Chen, S. E. Summerside

Conservation and Survey Division

No abstract provided.

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- Southern Panhandle Tablelands, D. C. Gosselin

Conservation and Survey Division

No abstract provided.

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- East Central Dissected Plains, D. C. Gosselin, J. Headrick, X-H. Chen, S. E. Summerside

Conservation and Survey Division

No abstract provided.

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- Republican River Valley And Dissected Plains, D. C. Gosselin, J. Headrick, X-H. Chen, S. E. Summerside

Conservation and Survey Division

No abstract provided.

Regional Hydrogeologic Summaries From Domestic Well-Water Quality In Rural Nebraska -- Southeastern Glacial Drift Area, D. C. Gosselin

Conservation and Survey Division

No abstract provided.

Data On Mineral Production In Nebraska, R. R. Burchett, D. Mohlman

Conservation and Survey Division

No abstract provided.

Burt County Test Hole Logs, Raymond R. Burchett, Frank A. Smith

Conservation and Survey Division

No abstract provided.

Polk County Test Hole Logs, Raymond R. Burchett, Frank A. Smith

Conservation and Survey Division

No abstract provided.

Geology Of The Liquid Propane Gas Storage Facility Near Greenwood, Nebraska, R. R. Burchett

Conservation and Survey Division

No abstract provided.

A Policy-Independent Secure X Server, Kirk Joseph Bittler

Dissertations and Theses

This thesis demonstrates that a secure X system can be designed and implemented to be independent of a particular security policy. The advantages and costs of a separation of security policy and enforcement are examined by developing a large scale application, the DX windowing system, on a DTOS platform. DTOS is a high assurance operating system that isolates policy decisions in a Security Server. A security conscious process, such as DX, eliminates policy considerations from the code. The process instead consults the Security Server and enforces the decisions that server derives from the policy. The DX architecture is described and …

Annual Departures From Average Annual Precipitation In Nebraska, 1876-1995/ Annual Installation Of Irrigation Wells (1937-1995), Conservation Survey Division

Conservation and Survey Division

No abstract provided.

Registered Irrigation Wells In Nebraska-Summer 1995, Mack Ann, Jim Weir, Jennifer Sharpe

Conservation and Survey Division

No abstract provided.

Groundwater-Level Changes In Nebraska, Predevelopment To Spring 1994, Mack Ann, Jim Weir, Jennifer Sharpe

Conservation and Survey Division

No abstract provided.

Status Of The Major Oyster Diseases In Virginia 1995 A Summary Of The Annual Monitoring Program, Lisa M. Ragone Calvo, Eugene M. Burreson

Reports

No abstract provided.

The Effects Of Mass Extinction On Escalation Of The Naticid Gastropod Predator-Prey System At The Eocene-Oligocene, Vicky D. Melland

Theses and Dissertations

In 1987, Vermeij proposed the hypothesis of escalation, which states that biological hazards, such as predation, have increased through the Phanerozoic. This hypothesis has been extremely controversial due to the fact that it assumes that biotic factors, such as predation, have had an important role in evolution. Several studies have focused on the validity of the hypothesis of escalation. Kelley and Hansen (1996) offered a modified exposition of the escalation hypothesis. The Kelley-Hansen hypothesis states that escalation cycles are punctuated by periods of mass extinction. The periods of mass extinction would preferentially eliminate the highly escalated prey and, therefore, a …

The Depositional Environment Of The Kisbey Sandstone From The Madison Group (Mississippian), North-Central North Dakota, Gregory D. Waltz

Theses and Dissertations

The Kisbey Sandstone, also known as the K-2 marker, was studied to understand its depositional environment. It occurs within the Madison Group (Mississippian) of North Dakota. The Madison Group is a regressive, near-shore sequence. In descending order, this Group comprises the Charles, Mission Canyon, and Lodgepole Formations. The K-2 marker appears as well-log defined unit between the Charles and Mission Canyon Formations. Seven counties comprise the 7100 square mile study area. They include Rolette, Bottineau, Renville, McHenry, Ward, Burke, Mountrail Counties, and the southern most adjacent townships in Canada.

For this study, 1677 well-logs were examined. These data were analyzed …

The Origin Of The Rock Lake Stratabound Copper-Silver Deposit, Rock Lake, Montana, Christopher B. (Christopher Borgen) Hemstad

WWU Graduate School Collection

The Rock Lake copper-silver deposit is a zoned, stratiform, red-bed type deposit, occurring within the Revett Formation of the Proterozoic Belt Supergroup. Structurally the deposit occurs in the west limb of an overturned syncline and is bounded to the west by the Rock Lake normal fault and to the east by the Libby Lakes thrust. At Rock Lake the copper-silver minerals are found in a zonally distributed copper-sulfide system consisting of seven gradational zones representing a migrating redox interface. The sulfide system is wedge shaped with a thick pyrite-galena core near the Rock Lake fault. Vertically and horizontally, from the …

Structure And Metamorphism Of The Kwoiek Creek Area, British Columbia, Kristine M. (Kristine Marie) Alvarez

WWU Graduate School Collection

A complex record of orogenesis is preserved in part of a large country rock septum within the southeast Coast Plutonic Complex (CPC) near the Kwoiek Creek area of British Columbia. The study area includes part of the large 90-84 Ma Scuzzy Pluton. Country rock is the Settler Schist near the pluton, and the slightly metamorphosed Permo-Jurassic Bridge River assemblage, a subduction-accretionary complex, and the hemipelagic Cayoosh assemblage. Earliest deformation produced isoclinal folds and an axial planar foliation. Subsequent folds are southwest vergent, and produced a spaced cleavage. High angle reverse faulting along the Bralorne-Kwoiek Creek Fault followed. The area then …

Nucleation And Growth Of Gan On Sapphire By Mbe, Steven Buczkowski

Graduate Theses, Dissertations, and Problem Reports

GaN was grown by molecular beam epitaxy in an effort to determine nucleation and growth conditions which lead to high quality, single-crystal films. Atomic force microscopy (AFM) was used to show that growth under Ga-rich conditions promotes the nucleation of films with large nucleation domains leading to a lower density of intrinsic defects related to domain boundaries. These conditions are also shown to promote a 2-D growth mode resulting in films with a high degree of nucleation domain coalescence and surface roughnesses below 2 nm. Addition of atomic hydrogen, using a thermally-cracked source, is shown to increase the growth rate …

The Stability Of Compressible Mixing Layers In Binary Gases, F. Kozusko, D. G. Lasseigne, C. E. Grosch, T. L. Jackson

Mathematics & Statistics Faculty Publications

We present the results of a study of the inviscid two-dimensional spatial stability of a parallel compressible mixing layer in a binary gas. The parameters of this study are the Mach number of the fast stream, the ratio of the velocity of the slow stream to that of the fast stream, the ratio of the temperatures, the composition of the gas in the slow stream and in the fast stream, and the frequency of the disturbance wave. The ratio of the molecular weight of the slow stream to that of the fast stream is found to be an important quantity …

A Family Of Parallel Runge-Kutta Pairs, P. Bogacki

Mathematics & Statistics Faculty Publications

Increasing availability of parallel computers has recently spurred a substantial amount of research concerned with designing explicit Runge-Kutta methods to be implemented on such computers. Here, we discuss a family of methods that require fewer processors than methods presently available do, still achieving a similar speed-up. In particular, (5,6) and (6,7) pairs are derived, that require a minimum number of function evaluations on two and three processors, respectively.

Surface Debye Temperature Measurement With Reflection High-Energy Electron Diffraction, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Measurement of the surface mean-square atomic vibrational amplitude, or equivalently the surface Debye temperature, with reflection high-energy electron diffraction is discussed. Low-index surfaces of lead are used as examples. Particular details are given about the temperature-dependent diffraction pattern of Pb(100) in the Debye-Waller region. The use of reflection high-energy electron diffraction for measurement of the substrate surface temperature in thin-film deposition chambers is suggested. © 1996 American Institute of Physics.

Decidability Of The Two-Quantifier Theory Of The Recursively Enumerable Weak Truth-Table Degrees And Other Distributive Upper Semi-Lattices, Klaus Ambos-Spies, Peter A. Fejer, Steffen Lempp, Manuel Lerman

Computer Science Faculty Publication Series

We give a decision procedure for the ∀∃-theory of the weak truth-table (wtt) degrees of the recursively enumerable sets. The key to this decision procedure is a characterization of the finite lattices which can be embedded into the r.e. wtt-degrees by a map which preserves the least and greatest elements: a finite lattice has such an embedding if and only if it is distributive and the ideal generated by its cappable elements and the filter generated by its cuppable elements are disjoint. We formulate general criteria that allow one to conclude that a distributive upper semi-lattice has a decidable two-quantifier …

Energy And Deforestation In Ghana: A Study Of Woodfuel-Deforestation Links In Rural Ghana, Iddrisu Adam

Theses and Dissertations (Comprehensive)

Forests are one of the most valuable natural resources of many countries, including Ghana. Timber and other forest products have contributed immensely to the development of the country. These same forests have been a source of sustenance to the Ghanian people. Most particularly, forests have been the principal source of domestic energy by way of providing woodfuels. The heavy reliance on forest resources is taking its toll on the health of Ghanaian forests. In recent years, there has been increased awareness of the depletion of trees—a problem that many researchers have attributed to the over-exploitation of forests especially for domestic …

Mechanical And Chemical Weathering Of Periglacial And Non-Periglacial Forms On The Eastern Fosheim Peninsula, Ellesmere Island (Northwest Territories), Cameron Lawrence Chadwick

Theses and Dissertations (Comprehensive)

The purpose of this study is to examine the differences in the mechanical and chemical weathering of different periglacial and non-periglacial forms on the eastern Fosheim Peninsula. Forms studied include: solifluction lobes, non-sorted stripes, polygons, mudboils, wetted sloped, dry ridge and wet meadow. Most sites including the periglacial forms of solifluction lobes, non-sorted stripes, and polygons show signs of chemical and mechanical weathering. The weathering found at all sites was minute but may be significant given the slow rates of weathering in this environment. The individual environmental variables of moisture and temperature levels do not appear to have a direct …

Managing External Threats To National Parks In Canada's Western Mountains (Alberta), George Yap

Theses and Dissertations (Comprehensive)

External threats to protected areas exist because the area encompassed by the legal boundaries of many protected areas is less than what is needed to maintain a minimum viable population of various animal species and some types of plant associations. While external stresses to parks are the result of a wide range of human activities, they threaten ecological integrity in two general ways: by contributing to habitat fragmentation, alienation and loss (HFAL), and/or undermining the long-term viability of transboundary animal populations. However, in comparison to internal threats, addressing external threats is considerably more complex since park managers have no legal …

Using Digital Elevation Models To Measure The Surface And Volumetric Change Of Athabasca Glacier, Alberta, Canada, 1919-1979, James Robb Reynolds

Theses and Dissertations (Comprehensive)

The Athabasca Glacier (52˚12'N, 117˚14'W) located at the Alberta-British Columbia border was studied to quantify its volumetric, area and elevation changes below 2400 m between 1919 and 1979. The data sources consist of maps produced using aerial and terrestrial photogrammetry in the years between 1919 and 1979. The maps were digitized and converted into raster digital elevation models (DEMs), the manipulation of which allowed values of surface and volumetric change to be calculated. These DEMs showed that between 1919 and 1979 the glacier lost 2.344 x 108m3 of volume and receded more than 1 km. Each of the source maps …

Relative Rates Of Sand Transport Through An Incipient Parabolic Dune At Pinery Provincial Park, Ontario (Ammophila Breviligulata, Calamovilfa Longifolia, Cakile Edentula, Juniperus Virginiana, Populus Deltoides), Sheri A. Longboat

Theses and Dissertations (Comprehensive)

Factors controlling the development, migration, and stability of an incipient parabolic dune in Pinery Provincial Park, Ontario were investigated in terms of grain size characteristics, rates of sediment transport, and local and regional winds. The parabolic dune, situated approximately 60 meters inland of Lake Huron, is dominated by sparsely scattered dune grass species of marram grass (Ammophila breviligulata), sand reed (Calamovilfa longifolia), and sea rocket (Cakile edentula). Small tree species of red cedar (Juniperus virginiana) and eastern cottonwood (Populus deltoides) emerge and increase in number beyond the parabolic dune. Mean grain sizes along a profile were coarsest on the beach …

A Functional Group Approach To Detecting Shifts In Macroalgal Communities Along A Disturbance Gradient, J. C. Phillips

Theses : Honours

A recently proposed hypothesis argued that morphologically and functionally similar macroalgae could be grouped to study the structure of macroalgal communities. It was argued that these functional groups can be used to predict changes to community composition that result from disturbance. This study examined whether the functional group model held in detecting changes in macroalgal community structure within one bioregion, by applying it to a habitat exposed to different levels of physical disturbance associated with wave exposure. Results obtained using a functional group approach were compared to those obtained using a species level approach. Three parallel reef lines in Marmion …

Modelling The Effects Of Rehabilitation And Changed Agricultural Practices In A Saline-Affected Rural Catchment, M. K. Heller

Theses : Honours

The Bremer river catchment, on the South-coast of Western Australia, is typical of most river catchments in this region in that it has been seriously affected by sedimentation, salinisation and eutrophication brought on by the gradual dominance of agricultural land management practices. Vegetated rehabilitation and changed agricultural land management practices (ie minimum / zero tillage) have now been widely adopted throughout the catchment in response to these degradation issues. This study examined the potential impact minimum / zero tillage, vegetated rehabilitation and remnant vegetation could have on both a farm and catchment wide scale. A Geographical Information System was developed …