Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Climate (2)
- Atmospheric chemistry (1)
- California Current (1)
- Cosmogenic Dating (1)
- Dam removal (1)
-
- Deformation processes (1)
- Deoxygenation (1)
- Dissolved oxygen (1)
- Dust (1)
- EBSD (1)
- Estuary (1)
- Finite Element Analysis and Mesh Generation (1)
- Fracture and Cracking (1)
- Geochronology (1)
- Glacier (1)
- Glaciology (1)
- Grenville (1)
- Heterogeneous Anisotropic Materials (1)
- Homogenization (1)
- Horse racing (1)
- Ice core (1)
- Last Glacial Maximum (1)
- Metagranite (1)
- Micromechanics (1)
- Monterey Bay (1)
- Movement patterns (1)
- Multibeam Bathymetry (1)
- Nonlinear Creep (1)
- Oceanography (1)
- Penman-Monteith evapotranspiration model (1)
- Publication Type
Articles 1 - 8 of 8
Full-Text Articles in Entire DC Network
Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook
Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook
Electronic Theses and Dissertations
This dissertation is concerned with the development of robust numerical solution procedures for the generalized micromechanical analysis of linear and nonlinear constitutive behavior in heterogeneous materials. Although the methods developed are applicable in many engineering, geological, and materials science fields, three main areas are explored in this work. First, a numerical methodology is presented for the thermomechanical analysis of heterogeneous materials with a special focus on real polycrystalline microstructures obtained using electron backscatter diffraction techniques. Asymptotic expansion homogenization and finite element analysis are employed for micromechanical analysis of polycrystalline materials. Effective thermoelastic properties of polycrystalline materials are determined and compared …
Declining Dissolved Oxygen In The Central California Current Region, Alice Ren
Declining Dissolved Oxygen In The Central California Current Region, Alice Ren
Electronic Theses and Dissertations
A potential consequence of climate change is a global decrease in dissolved oxygen at depth due to changes in the balance of ventilation, mixing, respiration, and photosynthesis in the oceans. Regionally, the California Current has experienced dissolved oxygen declines since the late 1980s with observations from Oregon and the Southern California Bight. Here, we present observations of declining dissolved oxygen along CalCOFI Line 67 off of Monterey Bay, in the Central California Current region, and investigate likely mechanisms. The hydrographic cruises obtained dissolved oxygen measurements 50-300 km from shore between 1998 and 2013, with quasi-seasonal sampling resolution. Dissolved oxygen decreased …
Shortnose Sturgeon (Acipenser Brevirostrum) Spawning Potential In The Penobscot River, Maine: Considering Dam Removals And Emerging Threats, Catherine Johnston
Shortnose Sturgeon (Acipenser Brevirostrum) Spawning Potential In The Penobscot River, Maine: Considering Dam Removals And Emerging Threats, Catherine Johnston
Electronic Theses and Dissertations
Dam removals from the Penobscot River in Maine restored access to freshwater habitat critical for the life cycle of endangered shortnose sturgeon. Prior to the dam removals, shortnose sturgeon spawning activity had not been documented. Instead, evidence suggested that individuals emigrated from the Penobscot River to spawn in the Kennebec complex, 140 km away. A central question of this thesis was whether spawning activity would commence in the first two years following dam removal. Consistent with pre-dam removal movement patterns determined using acoustic telemetry, the majority (78%) of tagged individuals emigrated from the Penobscot River at some point over the …
Sediment Accumulations Patterns In The Damariscotta River Estuary, Emily A. Chandler
Sediment Accumulations Patterns In The Damariscotta River Estuary, Emily A. Chandler
Electronic Theses and Dissertations
The tidally dominated Damariscotta River estuary is located on the south-central Maine coast. The elongate, north-south orientation of the estuary is characteristic of the indented shoreline in this region and a consequence of the bedrock structural framework, comprised of Paleozoic high-grade metasedimentary rocks. Pegmatite sills form bedrock constriction points that divide the estuary into seven distinct basins. The narrow, bending geometry and sill and basin morphology impact the distribution of sediment within the estuary and the hydrodynamics of the system. This study employs multibeam bathymetry surveys, sediment grab samples and radionuclide analysis (210Pb and 137Cs) of sediment …
Processes Leading To The Formation Of Deep Granitic Shear Zones In The Grenville Front Tectonic Zone, Ontario, Canada, Deborah J. Shulman
Processes Leading To The Formation Of Deep Granitic Shear Zones In The Grenville Front Tectonic Zone, Ontario, Canada, Deborah J. Shulman
Electronic Theses and Dissertations
The rheology of the deep crust influences the transmission of mantle stresses to the surface as well as the topographic relief of orogenic terrains. Since deformation in the deep crust is often localized in shear zones, we investigate the mechanical processes associated with strain localization to understand the rheology of the deep crust. Strain localizes due to a strength heterogeneity, which can be created by the activation of one or more weakening factors. Studying the mechanical processes and weakening factors that sustain strain localization in the deep crust is becoming increasingly important as geodynamic models become more computationally robust, and …
Modeling And Measurement Of Evaporation From Frequently Tilled Sandy Soils, Nicholas R. Lawson
Modeling And Measurement Of Evaporation From Frequently Tilled Sandy Soils, Nicholas R. Lawson
Electronic Theses and Dissertations
Moisture observation and control is the single largest factor that controls the mechanical properties of sand based surfaces used for thoroughbred horse racing. Currently the moisture content is estimated based on the experience and expertise of the superintendent and water is added as needed based on experience. While extensive modelling has been done on moisture loss from a range of soils with crop covers in agronomy, currently no method exists to estimate the evaporation from a surface that is tilled many times a day and remains in a partially compacted state. This thesis develops an evaporation model based on real …
Late Holocene Climate And Environmental Reconstruction Derived From The Asian Ice Core Array (Aica), Bjorn Grigholm
Late Holocene Climate And Environmental Reconstruction Derived From The Asian Ice Core Array (Aica), Bjorn Grigholm
Electronic Theses and Dissertations
Recent climate change has impacted natural and human systems across the Earth, emphasizing the need for greater understanding of both the existing and changing natural and anthropogenic forcing mechanisms and subsequent responses of the Earth’s climate system. High-resolution, multi-parameter ice core records retrieved and analyzed from two Asian Ice Core Array (AICA) sites, Geladaindong (central Tibetan Plateau) and Inilchek (central Tien Shan) were utilized to reconstruct atmospheric chemical concentrations and composition over the past ~100-500 years, improving the understanding of late Holocene climate and environmental variability in Asia. Both ice cores were analyzed for major and trace elements, major soluble …
Increasing The Resolution Of The Last Glacial Maximum Record In The Tropical Andes Using 10be Cosmogenic Surface-Exposure Dating In The Cordillera Carabaya, Peru, Zachary E. Mason
Increasing The Resolution Of The Last Glacial Maximum Record In The Tropical Andes Using 10be Cosmogenic Surface-Exposure Dating In The Cordillera Carabaya, Peru, Zachary E. Mason
Honors College
Owing to the abundance of heat and moisture, the tropics is a fundamental component of the global climate system. Yet the role of the tropics in climate remains poorly understood. The Andes are home to ~95% of all tropical glaciers, making this the ideal region for studying relationships between tropical glaciers and climate. I conducted a Beryllium-10 surface exposure dating experiment using ten quartz-bearing rock samples from a series of last glacial maximum (LGM) moraines in the Minas Tira glaciofluvial valley system, Cordillera Carabaya, Peru. The AMS measured sample dates (excluding outliers) range from 24.3 ± 0.5 ka to 19.4 …