2,148 research outputs found
Internship report: Louisiana State Museum
This internship report describes the student\u27s experiences while working for Louisiana state Museum in New Orleans, one of the largest and oldest historical complexes in the United states. Its mission is to collect, preserve and present the materials which document Louisiana\u27s cultural identity. Included in the Museum holdings are eight historic Vieux Carre properties, four of which function as museums, and an extensive permanent collection (over three million pieces) of fine, decorative, folk and textile arts; military and inventive artifacts; manuscripts; prints; maps; and photographs illustrating the culture and history of Louisiana
Work hard, play hard : exploring perceptions of play in times of rigor and high accountability
Dissertation supervisor: Dr. Barbara N. Martin.Includes vita.As school districts navigated data and how to evidence student growth and success, educational stakeholders felt the pressure of increased testing requirements. The additional pressure led to more teacher-directed lecturing and paperwork for students rather than more open-ended, project-oriented lessons and active activities (Elkind, 2007), consequently, increased accountability and rigor causes educational stakeholders to lose sight of the value of early childhood programs (Liston, Whitcomb, & Borko, 2007), and the value of play. This concurrent triangulation mixed methods study (Creswell, 2009; Mertens, 2010) explored adult stakeholder perceptions concerning the role of play as an educational tool in times of high rigor and accountability utilizing the lens of Piaget's (1929) constructivist learning theory (Bruner, 1996; Schweinhart, 2005). In the study, surveys were used to measure the connection between adult perceptions of play and school readiness. At the same time, adult perceptions regarding the role of play in a child's education were explored using qualitative interviews with adult stakeholders (e.g., administrators and teachers) throughout the state of Missouri. Collected data for this study was examined using inductive analysis as common themes emerged. All participants in this study alluded to the fact that play is learning in one form or another. Response trends also included the importance of developing social-emotional skills as well as working with the "whole child" rather than solely focusing on academics. To this end, we as a society are missing prime opportunities to better develop well-rounded children who not only comprehend academic concepts, but who also have healthy self-concepts as well as to understand and exhibit socially acceptable behaviors.Includes bibliographical references (pages 115-122)
Effects of Supernova Feedback on the Formation of Galaxies
We study the effects of Supernova (SN) feedback on the formation of galaxies
using hydrodynamical simulations in a Lambda-CDM cosmology. We use an extended
version of the code GADGET-2 which includes chemical enrichment and energy
feedback by Type II and Type Ia SN, metal-dependent cooling and a multiphase
model for the gas component. We focus on the effects of SN feedback on the star
formation process, galaxy morphology, evolution of the specific angular
momentum and chemical properties. We find that SN feedback plays a fundamental
role in galaxy evolution, producing a self-regulated cycle for star formation,
preventing the early consumption of gas and allowing disks to form at late
times. The SN feedback model is able to reproduce the expected dependence on
virial mass, with less massive systems being more strongly affected.Comment: To appear in "The Galaxy Disk in Cosmological Context"; Proceedings
of IAU254; 9-13 June 2008; Copenhagen; v2: typo corrected; uses iaus.cl
Reactivity and structure of CF3I on Ru(001)
A variety of surface-sensitive techniques are used to elucidate the reaction pathways, as well as adsorbate structures, associated with thermal activation of CF3J following adsorption on Ru(001) at 100 K. XPS shows that the C-I bond of CF3I dissociates below 200 K to form CF3(ad) and I(ad); the subsequent reactions of CF2 are best viewed as being regulated by the availability of surface sites. CF3(ad) dissociates to CF2(ad) below 200 K. Further CF3 dissociation, some of which is activated by H(ad), occurs between 200 and 400 K until all available sites are filled. Desorption of the remaining CF3, peaking at 705 K, once again opens surface sites for decomposition. This is followed by recombination of the products to form CF3(g). No evidence for CF(ad) is ever observed. Hydrogen coadsorption studies explain interesting features associated with fluorine evolution. HREELS and ESDIAD results indicate that CF3 adopts a tilted configuration on Ru(001)
Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies
We study the stellar discs and spheroids in eight simulations of galaxy formation within Milky Way mass haloes in a cold dark matter cosmology. The first paper in this series concentrated on disc properties. Here we extend this analysis to study how the formation history, structure and dynamics of discs and spheroids relate to the assembly history and structure of their haloes. We find that discs are generally young, with stars spanning a wide range of stellar age: the youngest stars define thin discs and have near-circular orbits, while the oldest stars form thicker discs that rotate âŒ2 times slower than the thin components, and have 2â3 times larger velocity dispersions. Unlike the discs, spheroids form early and on short
time-scales, and are dominated by velocity dispersion. We find great variety in their structure. The inner regions are bar- or bulge-like, while the extended outer haloes are rich in complex non-equilibrium structures such as stellar streams, shells and clumps. Our discs have very high in situ fractions, i.e. most of their stars formed in the disc itself. Nevertheless, there is a non-negligible contribution (âŒ15 per cent) from satellites that are accreted on nearly coplanar orbits. The inner regions of spheroids also have relatively high in situ fractions, but 65â85 per cent of their outer stellar population is accreted. We analyse the circular velocities, rotation
velocities and velocity dispersions of our discs and spheroids, both for gas and stars, showing that the dynamical structure is complex as a result of the non-trivial interplay between cooling and supernova heating.Fil: Scannapieco, Cecilia. Leibniz Institut Fur Astrophysik Potsdam; Alemania. Consejo Nacional de InvestigaciĂłnes CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de AstronomĂa y FĂsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomĂa y FĂsica del Espacio; ArgentinaFil: White, Simon D. M.. Gobierno de la Republica Federal de Alemania. Max Planck Institut Fur Astrophysik; AlemaniaFil: Springel, Volker. Gobierno de la Republica Federal de Alemania. Max Planck Institut Fur Astrophysik; AlemaniaFil: Tissera, Patricia Beatriz. Consejo Nacional de InvestigaciĂłnes CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de AstronomĂa y FĂsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomĂa y FĂsica del Espacio; Argentin
Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback
We have developed a new scheme to treat a multiphase interstellar medium in
smoothed particle hydrodynamics simulations of galaxy formation. This scheme
can represent a co-spatial mixture of cold and hot ISM components, and is
formulated without scale-dependent parameters. It is thus particularly suited
to studies of cosmological structure formation where galaxies with a wide range
of masses form simultaneously. We also present new algorithms for energy and
heavy element injection by supernovae, and show that together these schemes can
reproduce several important observed effects in galaxy evolution. Both in
collapsing systems and in quiescent galaxies our codes can reproduce the
Kennicutt relation between the surface densities of gas and of star formation.
Strongly metal-enhanced winds are generated in both cases with ratios of
mass-loss to star formation which are similar to those observed. This leads to
a self-regulated cycle for star formation activity. The overall impact of
feedback depends on galaxy mass. Star formation is suppressed at most by a
factor of a few in massive galaxies, but in low-mass systems the effects can be
much larger, giving star formation an episodic, bursty character. The larger
the energy fraction assumed available in feedback, the more massive the
outflows and the lower the final stellar masses. Winds from forming disks are
collimated perpendicular to the disk plane, reach velocities up to 1000 km/s,
and efficiently transport metals out of the galaxies. The asymptotically
unbound baryon fraction drops from >95 per cent to ~30 per cent from the least
to the most massive of our idealised galaxies, but the fraction of all metals
ejected with this component exceeds 60 per cent regardless of mass. Such winds
could plausibly enrich the intergalactic medium to observed levels.Comment: 18 pages, 13 figures, accepted for publication in MNRA
Make Art Real
The Make Art Real project aims to introduce new audiences to the arts. It supports Theme II of VCUâs Quest for Distinction by promoting and fostering creative expression through innovative collaborations. The project involves displaying existing connections between art and non-art disciplines, as well as making new connections. These unusual pairings are then placed on exhibition through a lunch-time lecture series named âUnexpected_Connections,â which allow faculty, staff, and students to lead and participate in discussions about the reality of art. The lecture series is the first sustainable and reoccurring program to be held in the Depot building, a multidisciplinary facility which is intended to foster interdisciplinary collaborations. The targeted audience includes faculty, staff, students, and members of the greater VCU community
Simulating avian species and foraging group responses to fuel reduction treatments in coniferous forests
Over a century of fire suppression activities have altered the structure and composition of mixed conifer forests throughout the western United States. In the absence of fire, fuels have accumulated in these forests causing concerns over the potential for catastrophic wildfires. Fuel reduction treatments are being used on federal and state lands to reduce the threat of wildfire by mechanically removing biomass. Although these treatments result in a reduction in fire hazard, their impact on wildlife is less clear. We use a multi-species occupancy modeling approach to build habitat-suitability models for 46 upland forest birds found in the Lake Tahoe Basin in the Sierra Nevada based on forest structure and abiotic variables. Using a Bayesian hierarchical framework, we predict species-specific and community-level responses to changes in forest structure and make inferences about responses of important avian foraging guilds. Disparities within and among foraging group responses to canopy cover, tree size and shrub cover emphasized the complexities in managing forests to meet biodiversity goals. Based on our species-specific model results, we predicted changes in species richness and community similarity under forest prescriptions representing three management practices: no active management, a typical fuel reduction treatment that emphasizes spacing between trees, and a thinning prescription that creates structural heterogeneity. Simulated changes to structural components of the forest analogous to management practices to reduce fuel loads clearly affected foraging groups differentially despite variability in responses within guilds. Although species richness was predicted to decrease slightly under both simulated fuels reduction treatments, the prescription that incorporated structural heterogeneity retained marginally higher species richness. The composition of communities supported by different management alternatives was influenced by urbanization and management practice, emphasizing the importance of creating heterogeneity at the landscape scale
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