Actions of higher-rank lattices on free groups

If $G$ is a semisimple Lie group of real rank at least 2 and $\Gamma$ is an irreducible lattice in $G$, then every homomorphism from $\Gamma$ to the outer automorphism group of a finitely generated free group has finite image.Comment: 11 pages, no figures. Final version. To appear in Compositio Mat

Damage prediction in cross-plied curved composite laminates

Analytical and experimental work is detailed which is required to predict delamination onset and growth in a curved cross plied composite laminate subjected to static and fatigue loads. The composite used was AS4/3501/6, graphite/epoxy. Analytically, a closed form stress analysis and 2-D and 3-D finite element analyses were conducted to determine the stress distribution in an undamaged curved laminate. The finite element analysis was also used to determine values of strain energy release rate at a delamination emanating from a matrix crack in a 90 deg ply. Experimentally, transverse tensile strength and fatigue life were determined from flat 90 deg coupons. The interlaminar tensile strength and fatigue life were determined from double cantilevered beam specimens. Cross plied curved laminates were tested statically and in fatigue to give a comparison to the analytical predictions. A comparison of the fracture mechanics life prediction technique and the strength based prediction technique is given

A Machine-Aided Seismic Signal Analysis Workflow for Subsurface Faults and Facies Visualization and Interpretation, South Central Anadarko Basin, Oklahoma

Seismic attribute analysis enhances the understanding of subsurface geology and has continually gained traction in the oil and gas industry since the 1970’s. Many seismic attributes are available for petroleum geoscientists. This research intends to provide insight to an analytical attribute workflow for rock property estimation in the Anadarko basin of Oklahoma that is prolific in oil and gas exploration, with a particular focus on seismic texture. 3-D volumes processed for seismic texture facies and structure enhance geophysical investigation and interpretation of amplitude data. This study will contribute valuable insight to reservoir studies and the potential for texture attribute well calibration across exploration. Seismic responses are directly related only to the velocity and density of the rocks and fluids present in the subsurface. An analytical attribute workflow will provide insight to depositional facies, structural geology, and small-scale features that are otherwise unclear from reflection seismology alone. The Pennsylvanian sandstones, the Mississippian and Devonian carbonates, and early Mississippian Woodford Shale are three proven petroleum targets that can be further evaluated within the Mountaineer 3D seismic data set. Application of an analytical attribute workflow with an emphasis on seismic texture attributes provides an insight to the subsurface basin structures and depositional facies, which are fundamental for successful exploration for and effective development of conventional and unconventional energy resources in the basin

Relevance of Tidal Heating on Large TNOs

We examine the relevance of tidal heating for large Trans-Neptunian Objects, with a focus on its potential to melt and maintain layers of subsurface liquid water. Depending on their past orbital evolution, tidal heating may be an important part of the heat budget for a number of discovered and hypothetical TNO systems and may enable formation of, and increased access to, subsurface liquid water. Tidal heating induced by the process of despinning is found to be particularly able to compete with heating due to radionuclide decay in a number of different scenarios. In cases where radiogenic heating alone may establish subsurface conditions for liquid water, we focus on the extent by which tidal activity lifts the depth of such conditions closer to the surface. While it is common for strong tidal heating and long lived tides to be mutually exclusive, we find this is not always the case, and highlight when these two traits occur together.Comment: Submitted to Icaru

Future trends of nursing homes

Introduction: Nursing homes are a major part of the long term care sector and have provided services to elders and the disabled population for years. Regulation change and new demands from the market have forced nursing homes to adapt. The purpose of this literature review was to analyze current regulation in place in the nursing home sector and determine how nursing homes will adapt and continue to provide quality care to patients in the future. Methodology: The methodology of this research was a literature review. Overall, there were 4 databases used to gather research and 35 sources were used throughout the entirety of the paper. Results: Within our findings, there were several sources to support our claims. The research that was gathered was analyzed to determine the future use and demand of nursing homes. The results supported the original hypothesis that nursing homes will undergo changes in the inner culture and policy, but they will remain a staple in the long term care sector. Discussion/Conclusion: Nursing homes have been around for years and research has shown that adjustments are constantly being made in regulation and the individual culture or attractiveness of every nursing home. Through these changes, nursing homes will remain to attract large demand from the elderly population that is rapidly growing. Thus, nursing homes will continue to provide services to those in need

Modelling the inorganic nitrogen behaviour in a small Mediterranean forested catchment, Fuirosos (Catalonia)

The aim of this work was to couple a nitrogen (N) sub-model to already existent hydrological lumped (LU4-N) and semi-distributed (LU4-R-N and SD4-R-N) conceptual models, to improve our understanding of the factors and processes controlling nitrogen cycling and losses in Mediterranean catchments. The N model adopted provides a simplified conceptualization of the soil nitrogen cycle considering mineralization, nitrification, immobilization, denitrification, plant uptake, and ammonium adsorption/desorption. It also includes nitrification and denitrification in the shallow perched aquifer. We included a soil moisture threshold for all the considered soil biological processes. The results suggested that all the nitrogen processes were highly influenced by the rain episodes and that soil microbial processes occurred in pulses stimulated by soil moisture increasing after rain. Our simulation highlighted the riparian zone as a possible source of nitrate, especially after the summer drought period, but it can also act as an important sink of nitrate due to denitrification, in particular during the wettest period of the year. The riparian zone was a key element to simulate the catchment nitrate behaviour. The lumped LU4-N model (which does not include the riparian zone) could not be validated, while both the semi-distributed LU4-R-N and SD4-R-N model (which include the riparian zone) gave satisfactory results for the calibration process and acceptable results for the temporal validation process

Commensurations of Aut(FN){{\rm{Aut}}}(F_N) and its Torelli subgroup

For $N \geq 3$, the abstract commensurators of both ${{\rm{Aut}}}(F_N)$ and its Torelli subgroup ${{\rm{IA}}}_N$ are isomorphic to ${{\rm{Aut}}}(F_N)$ itself.Comment: 29 pages, 5 figure

Abundances and search for vertical stratification in the atmospheres of four HgMn stars

Using high resolution, high-S/N archival UVES spectra, we have performed a detailed spectroscopic analysis of 4 chemically peculiar HgMn stars (HD 71066, HD 175640, HD 178065 and HD 221507). Using spectrum synthesis, mean photospheric chemical abundances are derived for 22 ions of 16 elements. We find good agreement between our derived abundances and those published previously by other authors. For the 5 elements that present a sufficient number of suitable lines, we have attempted to detect vertical chemical stratification by analyzing the dependence of derived abundance as a function of optical depth. For most elements and most stars we find no evidence of chemical stratification with typical 3\sigma upper limits of \Delta\log N_elem/N_tot~0.1-0.2 dex per unit optical depth. However, for Mn in the atmosphere of HD 178065 we find convincing evidence of stratification. Modeling of the line profiles using a two-step model for the abundance of Mn yields a local abundance varying approximately linearly by ~0.7 dex through the optical depth range log \tau_5000=-3.6 to -2.8.Comment: 11 figures, 9 tables, table 6-9 (online material), accepted by MNRA

Historic Douglas-Fir Colonization and Land Use Practices at Restoration Sites Near Eugene, OR

49 pages. A thesis presented to the Department of Environment Science and the Clark Honors College of the University of Oregon in partial fulfillment of the requirements for degree of Bachelor of Science, Spring 2015.Prior to Euro-American settlement in the Willamette Valley, the Kalapuya indigenous group conducted prairie burning to incite annual subsistence rounds of native prairie resources. However, the frequency of fire declined after replacement of indigenous culture with Euro-American settlements and the subsequent introduction of livestock grazing. This research aims to use Douglas-fir core data and vegetative extent comparisons from 1853-54, 1936, and 2011 at three preservation sites near Eugene, OR, to determine whether conifer colonization in historic oak savanna habitat occurred consistently, or was concentrated in one or more specific time periods as a result of external forces related to this shift in land use. References to General Land Office Survey data from 1853-54 and aerial photos from 1936 recreate historic vegetation cover and relate site histories to extracted Douglas-fir core ages and accounts of historic land use. The absence of core data prior to 1903 and the rapidity of forest advance from 1853-1936 are suggestive of a surge in colonization after the turn of the 20th century. However, the lack of site specific land use history is not conclusive in determining which management technique was the most influential in propagating forest advance