1,002 research outputs found
The Application of Paperless Processes to Improve Data Management within Small to Medium Businesses
Businesses are creating new value by implementing new processes built on modern tools. Small businesses, though, with much fewer resources than the most significant competitors, cannot follow the same path. How can these businesses use standard, widely available tools and techniques to improve their processes and create value within their business? This paper discusses the implementation of paperless processes using the electronic form technology, Google Forms, within the Honors Program at Georgia Southern University over two years. Action research methods were used to guide the research and implementation of new processes. Through the introduction of cloud-based electronic forms and process automation, process steps relying on paper and manual entry of data were reduced, increasing overall process quality
CCD time-series photometry of the globular cluster NGC 5053: RR Lyrae, Blue Stragglers and SX Phoenicis stars revisited
We report the results of CCD , and time-series photometry of the
globular cluster NGC 5053. New times of maximum light are given for the eight
known RR Lyrae stars in the field of our images and their periods are revised.
Their light curves were Fourier decomposed to estimate their physical
parameters. A discussion on the accuracy of the Fourier-based iron abundances,
temperatures, masses and radii is given. New periods are found for the 5 known
SX Phe stars and a critical discussion of their secular period changes is
offered. The mean iron abundance for the RR Lyrae stars is found to be [Fe/H]
and lower values are not supported by the present
analysis. The absolute magnitude calibrations of the RR Lyrae stars yield an
average true distance modulus of or a distance of kpc. Comparison of the observational CMD with theoretical isochrones
indicates an age of Gyrs for the cluster. A careful
identification of all reported Blue Stragglers (BS) and their magnitudes
leads to the conclusion that BS12, BS22, BS23 and BS24 are not BS. On the other
hand, three new BS are reported. Variability was found in seven BS, very likely
of the SX Phe type in five of them, and in one red giant star. The new SX Phe
stars follow established relationships and indicate a distance in
agreement with the distance from the RR Lyrae stars.Comment: 21 pages, 16 figures, 11 tables. Accepted for publication in MNRA
Laser-induced Precession of Magnetization in GaMnAs
We report on the photo-induced precession of the ferromagnetically coupled Mn
spins in (Ga,Mn)As, which is observed even with no external magnetic field
applied. We concentrate on various experimental aspects of the time-resolved
magneto-optical Kerr effect (TR-MOKE) technique that can be used to clarify the
origin of the detected signals. We show that the measured data typically
consist of several different contributions, among which only the oscillatory
signal is directly connected with the ferromagnetic order in the sample.Comment: 4 pages, 5 figure
Femoral Neck Anteversion: Values, Development, Measurement, Common Problems
The femoral neck anteversion angle is an important factor for hip stability and normal
walking. It is multifactoral result of evolution, heredity, fetal development, intrauterine
position, and mechanical forces. Abnormal FNA sometimes can be associated
with many clinical problems ranging from harmless intoeing gait in the early childhood,
to disabling osteoarthritis of the hip and the knee in the adults.
In most cases is associated with minor functional problems in children during growth,
but cause a concern in parents for children future. The child must be examined carefully
and an accurate diagnosis must be established. The most important part of care is observation
of the children. If abnormal femoral neck anteversion produces severe functional
disability, derotational osteotomy should be done, but delayed until late childhoo
Stellar impact on disequilibrium chemistry and on observed spectra of hot Jupiter atmospheres
In this work we study the effect of disequilibrium processes on mixing ratio
profiles of neutral species and on the simulated spectra of a hot Jupiter
exoplanet that orbits stars of different spectral types. We also address the
impact of stellar activity that should be present to a different degree in all
stars with convective envelopes. We used the VULCAN chemical kinetic code to
compute number densities of species. The temperature-pressure profile of the
atmosphere was computed with the HELIOS code. We also utilized the -ReX
forward model to predict the spectra of planets in primary and secondary
eclipses. In order to account for the stellar activity we made use of the
observed solar XUV spectrum taken from Virtual Planetary Laboratory (VPL) as a
proxy for an active sun-like star. We find large changes in mixing ratios of
most chemical species in planets orbiting A-type stars that radiate strong XUV
flux inducing a very effective photodissociation. For some species, these
changes can propagate very deep into the planetary atmosphere to pressures of
around 1 bar. To observe disequilibrium chemistry we favor hot Jupiters with
temperatures Teq=1000 K and ultra-hot Jupiters with Teq=3000$ K that also have
temperature inversion in their atmospheres. On the other hand, disequilibrium
calculations predict little changes in spectra of planets with intermediate
temperatures. We also show that stellar activity similar to the one of the
modern Sun drives important changes in mixing ratio profiles of atmospheric
species. However, these changes take place at very high atmospheric altitudes
and thus do not affect predicted spectra. We estimate that the effect of
disequilibrium chemistry in planets orbiting nearby bright stars could be
robustly detected and studied with future missions with spectroscopic
capabilities in infrared such as, e.g., JWST and ARIEL.Comment: 17 pages, 12 figure
Dwarf Cepheids in the Carina Dwarf Spheroidal Galaxy
We have discovered 20 dwarf Cepheids (DC) in the Carina dSph galaxy from the
analysis of individual CCD images obtained for a deep photometric study of the
system. These short-period pulsating variable stars are by far the most distant
(~100 kpc) and faintest (V ~ 23.0) DCs known. The Carina DCs obey a
well-defined period-luminosity relation, allowing us to readily distinguish
between overtone and fundamental pulsators in nearly every case. Unlike RR Lyr
stars, the pulsation mode turns out to be uncorrelated with light-curve shape,
nor do the overtone pulsators tend towards shorter periods compared to the
fundamental pulsators. Using the period-luminosity (PL) relations from Nemec et
al. (1994 AJ, 108, 222) and McNamara (1995, AJ, 109, 1751), we derive (m-M)_0 =
20.06 +/- 0.12, for E(B-V) = 0.025 and [Fe/H] = -2.0, in good agreement with
recent, independent estimates of the distance/reddening of Carina. The error
reflects the uncertainties in the DC distance scale, and in the metallicity and
reddening of Carina. The frequency of DCs among upper main sequence stars in
Carina is approximately 3%. The ratio of dwarf Cepheids to RR Lyr stars in
Carina is 0.13 +/- 0.10, though this result is highly sensitive to the
star-formation history of Carina and the evolution of the Horizontal Branch. We
discuss how DCs may be useful to search effectively for substructure in the
Galactic halo out to Galactocentric distances of ~100 kpc.Comment: 20 pages of text, 7 figure
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