5,527 research outputs found
Temperature Corrections to Conformal Field Theory
We consider finite temperature dynamical correlation functions in the
interacting delta-function Bose gas. In the low-temperature limit the
asymptotic behaviour of correlation functions can be determined from conformal
field theory. In the present work we determine the deviations from conformal
behaviour at low temperatures.Comment: 8 pages, 3 figure
Mississippi Industrial and Training School Band, Columbia, Mississippi, ca. 1918
This black and white photograph is a rare original photograph of the Mississippi Industrial and Training School Band of Columbia, Mississippi. The photograph is taken on the steps in front of a columned structure. The band members are all boys, uniformed, displaying their instruments with the Training School banner behind them. The back of the photograph is stamped with the photographer\u27s information in the center and Jack Sanford is handwritten near the top. The photograph is mounted on a dark board and the edges of the board are torn.https://scholarsjunction.msstate.edu/mss-lampton-images-ms-pine-belt/1252/thumbnail.jp
Evidence for DCO+ as a probe of ionization in the warm disk surface
In this Letter we model the chemistry of DCO in protoplanetary disks.
We find that the overall distribution of the DCO abundance is
qualitatively similar to that of CO but is dominated by thin layer located at
the inner disk surface. To understand its distribution, we investigate the
different key gas-phase deuteration pathways that can lead to the formation of
DCO. Our analysis shows that the recent update in the exothermicity of
the reaction involving CHD as a parent molecule of DCO favors
deuterium fractionation in warmer conditions. As a result the formation of
DCO is enhanced in the inner warm surface layers of the disk where X-ray
ionization occurs. Our analysis points out that DCO is not a reliable
tracer of the CO snow line as previously suggested. We thus predict that
DCO is a tracer of active deuterium and in particular X-ray ionization of
the inner disk.Comment: Accepted for publication in the Astrophysical Journal Letters (ApJL).
11 pages, 5 figure
The actual impedance of non-reflecting boundary conditions : implications for the computation of resonators
Non-reflecting boundary conditions are essential elements in the computation of many compressible flows: such simulations are very sensitive to the treatment of acoustic waves at boundaries. Non-reflecting conditions allow acoustic waves to propagate through boundaries with zero or small levels of reflection into the domain. However, perfectly non-reflecting conditions must be avoided because they can lead to ill-posed problems for the mean flow. Various methods have been proposed to construct boundary conditions which can be sufficiently non-reflecting for the acoustic field while still making the mean-flow problem well posed. This paper analyses a widely-used technique for non-reflecting outlets (Rudy and Strikwerda, Poinsot and Lele). It shows that the correction introduced by these authors can lead to large reflection levels and non-physical resonant behaviors. A simple scaling is proposed to evaluate the relaxation coefficient used in theses methods for a non-reflecting outlet. The proposed scaling is tested for simple cases (ducts) both theoretically and numerically
Promoting Healthy Lifestyles for Extension Employees: An Exploratory Study
Employee health is regarded as a strategic advantage with individual, organizational, and societal benefits. This study sought to describe the major health issues, motivations, barriers, and needs related to healthy lifestyles for Cooperative Extension employees. A total of 16 focus groups were conducted throughout Tennessee with 105 participants. Separate focus groups were conducted with seven groups of University of Tennessee Extension employees: administrative assistants, county agents, county directors, program assistants, departmental faculty, administrators, and professional staff. Findings indicate chronic stress as the dominant health issue. Respondents were motivated to stay healthy to be role models for good health, among other reasons. From an organizational standpoint, respondents reported that both an organizational culture that does not prioritize health and their job demands kept them from achieving optimum health. From a personal standpoint, respondents reported that a lack of time for healthy eating and physical activity and their own over-engagement with their work were barriers to health. Employees desired a coordinated, substantial organizational shift toward a culture of wellness that includes an effective employee wellness program. Employees indicated that a culture of wellness would result in employees who represent more balanced lives, thereby setting a better example for those served by Extension
Mechanisms for Lasing with Cold Atoms as the Gain Medium
We realize a laser with a cloud of cold rubidium atoms as gain medium, placed
in a low-finesse cavity. Three different regimes of laser emission are observed
corresponding respectively to Mollow, Raman and Four Wave Mixing mechanisms. We
measure an output power of up to 300 W and present the main properties of
these different lasers in each regime
Diffusion of a liquid nanoparticle on a disordered substrate
We perform molecular dynamic simulations of liquid nanoparticles deposited on
a disordered substrate. The motion of the nanoparticle is characterised by a
'stick and roll' diffusive process. Long simulation times (),
analysis of mean square displacements and stacking time distribution functions
demonstrate that the nanoparticle undergoes a normal diffusion in spite of long
sticking times. We propose a phenomenological model for the size and
temperature dependence of the diffusion coefficient in which the activation
energy scales as .Comment: Accepted for publication in Phys. Rev.
Theories of developmental dyslexia: Insights from a multiple case study of dyslexic adults
A multiple case study was conducted in order to assess three leading theories of developmental dyslexia: the phonological, the magnocellular (auditory and visual) and the cerebellar theories. Sixteen dyslexic and 16 control university students were administered a full battery of psychometric, phonological, auditory, visual and cerebellar tests. Individual data reveal that all 16 dyslexics suffer from a phonological deficit, 10 from an auditory deficit, 4 from a motor deficit, and 2 from a visual magnocellular deficit. Results suggest that a phonological deficit can appear in the absence of any other sensory or motor disorder, and is sufficient to cause a literacy impairment, as demonstrated by 5 of the dyslexics. Auditory disorders, when present, aggravate the phonological deficit, hence the literacy impairment. However, auditory deficits cannot be characterised simply as rapid auditory processing problems, as would be predicted by the magnocellular theory. Nor are they restricted to speech. Contrary to the cerebellar theory, we find little support for the notion that motor impairments, when found, have a cerebellar origin, or reflect an automaticity deficit. Overall, the present data support the phonological theory of dyslexia, while acknowledging the presence of additional sensory and motor disorders in certain individuals
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