874 research outputs found
The Effects of Career Commitment, Distress, and Persistence on Academic Success among Undergraduate Baccalaureate Nursing Students
Title from PDF of title page viewed August 21, 2018Dissertation advisor: Ann CaryVitaIncludes bibliographical references (pages 110-123)Thesis (Ph.D.)--School of Nursing and Health Studies. University of Missouri--Kansas City, 2018The ability of students, specifically in higher education environments, to persist is a
critical determinant of academic success. Student success is especially precarious within
programs of nursing, where curricula include clinical, laboratory, and didactic content.
Identifying and describing the barriers and facilitators to nursing student persistence
provides a blueprint to appropriately use financial and human resources as well as determine
the effect student demographic variables has on desiring, attending, or benefiting from
persistence interventions. The outcome of this study can guide the deployment of
institutional resources to provide persistence-based interventions that are evidence-based.
Framed by Tinto’s Theory of Student Departure, this study assessed the effects of career
commitment, distress, and persistence on academic success among undergraduate
baccalaureate nursing students. Findings indicated a significant relationship between
persistence, emotional concerns (a subscale of distress), and the outcome variable of
academic success.Introduction -- Review of the literature -- Methods -- Data analysis -- Conclusions -- Appendix A. Tinto's Model of student departure -- Appendix B. Kennel's proposed model derived from results of study -- Appendix C. Consent for study participation -- Appendix D. Study surveys -- Appendix E. Demographic questions -- Appendix F. Permission
Current driven electrostatic and electromagnetic ion cyclotron instabilities
Growth rates and parameter dependences are calculated for the current driven instabilities of electrostatic (with finite-beta corrections) and electromagnetic ion cyclotron waves. For 0.25 (T sub e)/(T sub i) 2.5, ion cyclotron waves have large growth rates, while ion acoustic waves are still stable. In fusion devices, where electrostatic waves may be stable, electromagnetic ion cyclotron waves are unstable for beta sub i 0.001
The Effect of High-Intensity and Moderate-Intensity Exercise on Enjoyment and General Mood
Please download pdf version here
Spatial Evidence for Transition Radiation in a Solar Radio Burst
Microturbulence, i.e. enhanced fluctuations of plasma density, electric and
magnetic fields, is of great interest in astrophysical plasmas, but occurs on
spatial scales far too small to resolve by remote sensing, e.g., at ~ 1-100 cm
in the solar corona. This paper reports spatially resolved observations that
offer strong support for the presence in solar flares of a suspected radio
emission mechanism, resonant transition radiation, which is tightly coupled to
the level of microturbulence and provides direct diagnostics of the existence
and level of fluctuations on decimeter spatial scales. Although the level of
the microturbulence derived from the radio data is not particularly high,
/n^2 ~ 10^{-5}$, it is large enough to affect the charged particle
diffusion and give rise to effective stochastic acceleration. This finding has
exceptionally broad astrophysical implications since modern sophisticated
numerical models predict generation of much stronger turbulence in relativistic
objects, e.g., in gamma-ray burst sources.Comment: 13 pages, 4 figures, ApJL accepte
Spatially resolved X-ray spectroscopy and modeling of the nonthermal emission of the PWN in G0.9+0.1
We performed a spatially resolved spectral X-ray study of the pulsar wind
nebula (PWN) in the supernova remnant G0.9+0.1. Furthermore we modeled its
nonthermal emission in the X-ray and very high energy (VHE, E > 100 GeV)
gamma-ray regime. Using Chandra ACIS-S3 data, we investigated the east-west
dependence of the spectral properties of G0.9+0.1 by calculating hardness
ratios. We analyzed the EPIC-MOS and EPIC-pn data of two on-axis observations
of the XMM-Newton telescope and extracted spectra of four annulus-shaped
regions, centered on the region of brightest emission of the source. A radially
symmetric leptonic model was applied in order to reproduce the observed X-ray
emission of the inner part of the PWN. Using the optimized model parameter
values obtained from the X-ray analysis, we then compared the modeled inverse
Compton (IC) radiation with the published H.E.S.S. gamma-ray data. The spectral
index within the four annuli increases with growing distance to the pulsar,
whereas the surface brightness drops. With the adopted model we are able to
reproduce the characteristics of the X-ray spectra. The model results for the
VHE gamma radiation, however, strongly deviate from the H.E.S.S. data.Comment: 8 pages, 7 figures, accepted for publication in Astronomy &
Astrophysic
Flares in GRB afterglows from delayed magnetic dissipation
One of the most intriguing discoveries made by the Swift satellite is the
flaring activity in about half of the afterglow lightcurves. Flares have been
observed on both long and short duration GRBs and on time scales that range
from minutes to ~1 day after the prompt emission. The rapid evolution of some
flares led to the suggestion that they are caused by late central engine
activity. Here, I propose an alternative explanation that does not need
reviving of the central engine. Flares can be powered by delayed magnetic
dissipation in strongly magnetized (i.e. with initial Poynting to kinetic flux
ratio \simmore 1) ejecta during its deceleration due to interaction with the
external medium. A closer look at the length scales of the dissipation regions
shows that magnetic dissipation can give rise to fast evolving and energetic
flares. Multiple flares are also expected in the context of the model.Comment: 5 pages, accepted for publication in A&A Letter
Cold ultrarelativistic pulsar winds as potential sources of galactic gamma-ray lines above 100 GeV
The evidence of a line-like spectral feature at 130 GeV recently reported
from some parts of the galactic plane poses serious challenges for any
interpretation of this surprise discovery. It is generally believed that the
unusually narrow profile of the spectral line cannot be explained by
conventional processes in astrophysical objects, and, if real, is likely to be
associated with Dark Matter. In this paper we argue that cold ultrarelativistic
pulsar winds can be alternative sources of very narrow gamma-ray lines. We
demonstrate that Comptonization of a cold ultrarelativistic electron-positron
pulsar wind in the deep Klein-Nishina regime can readily provide very narrow
distinct gamma-ray line features. To verify this prediction, we produced photon
count maps based on the Fermi LAT data in the energy interval 100 to 140 GeV.
We confirm earlier reports of the presence of marginal gamma-ray line-like
signals from three regions of the galactic plane. Although the maps show some
structure inside these regions, unfortunately the limited photon statistics do
not allow any firm conclusion in this regard. The confirmation of 130 GeV line
emission by low-energy threshold atmospheric Cherenkov telescope systems, in
particular by the new 27 m diameter dish of the H.E.S.S. array, would be
crucial for resolving the spatial structure of the reported hotspots, and thus
for distinguishing between the Dark Matter and Pulsar origins of the `Fermi
Lines'.Comment: 5 pages. 4 figure
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