2,453 research outputs found
Establishing an Equitable and Fair Admissions System for an Online Doctoral Program
The field of educational technology has seen marked growth from just a small number of distance-based doctoral programs to nearly 20 today. Creating and sustaining a quality doctoral program of any kind requires a substantial amount of work; the additional challenges of online programs both increases and changes the nature of the efforts required. Among these challenges is creating an admissions process that treats people fairly, does not create a burdensome system for applicants or those involved in the selection process, and ensures the selection of a solid foundation of high quality candidates with whom faculty can mentor, who add value to the program, and who can benefit from the program. This paper explores common admissions requirements among institutions offering a distance or hybrid doctorate in educational technology and examines the specific admissions system used by the Department of Educational Technology at Boise State University
Open Access Journals in Educational Technology: Results of a Survey of Experienced Users
As the academic publishing industry evolves, there has been an unprecedented growth of open access journals (OAJs). In educational technology alone, with an estimated 270 associated journals, nearly one-third are designated as open. Though OAJs are lauded for what their availability can contribute to social justice issues (reduction of subscription requirement barriers), some remain suspicious of the content found in them and question the legitimacy of publishing in them. In this study, we sought to discover the opinions of educational technology scholars about OAJs in their own field. We were able to learn which OAJs were deemed to be most valuable, as well as the characteristics of OAJs thought to be particularly important
H-alpha Imaging with HST+NICMOS of An Elusive Damped Ly-alpha Cloud at z=0.6
Despite previous intensive ground-based imaging and spectroscopic campaigns
and wide-band HST imaging of the z=0.927 QSO 3C336 field, the galaxy that hosts
the damped Ly-alpha system along this line-of-sight has eluded detection. We
present a deep narrow-band H-alpha image of the field of this z=0.656 damped
Ly-alpha absorber, obtained through the F108N filter of NICMOS 1 onboard the
Hubble Space Telescope. The goal of this project was to detect any H-alpha
emission 10 times closer than previous studies to unveil the damped absorber.
We do not detect H-alpha emission between 0.05'' and 6'' (0.24 and 30
kpc) from the QSO, with a 3-sigma flux limit of
erg/s/cm^2 for an unresolved source, corresponding to a star formation rate
(SFR) of M_sun/yr. This leads to a 3-sigma upper limit of 0.15
M_sun/yr/kpc^2 on the SFR density, or a maximum SFR of 1.87 M_sun/yr assuming a
disk of 4 kpc in diameter. This result adds to the number of low redshift
damped Ly-alpha absorbers that are not associated with the central regions of
Milky-Way-like disks. Damped Ly-alpha absorption can arise from high density
concentrations in a variety of galactic environments including some that,
despite their high local HI densities, are not conducive to widespread star
formation.Comment: 18 pages, 3 figures. Replaced to match published version in ApJ, 550,
585 (Apr 1 2001
Parametric tests of a traction drive retrofitted to an automotive gas turbine
The results of a test program to retrofit a high performance fixed ratio Nasvytis Multiroller Traction Drive in place of a helical gear set to a gas turbine engine are presented. Parametric tests up to a maximum engine power turbine speed of 45,500 rpm and to a power level of 11 kW were conducted. Comparisons were made to similar drives that were parametrically tested on a back-to-back test stand. The drive showed good compatibility with the gas turbine engine. Specific fuel consumption of the engine with the traction drive speed reducer installed was comparable to the original helical gearset equipped engine
Are There Local Analogs of Lyman Break Galaxies?
To make direct comparisons in the rest-far-ultraviolet between LBGs at z~3
and more local star-forming galaxies, we use HST/STIS to image a set of 12
nearby (z<0.05) HII galaxies in the FUV and a set of 14 luminous compact blue
galaxies (LCBGs) at moderate redshift (z~0.5) in the NUV, corresponding to the
rest-FUV. We then subject both sets of galaxy images and those of LBGs at z~3
to the same morphological and structural analysis. We find many qualitative and
quantitative similarities between the rest-FUV characteristics of distant LBGs
and of the more nearby starburst samples, including general morphologies,
sizes, asymmetries, and concentrations. Along with some kinematic similarities,
this implies that nearby HII galaxies and LCBGs may be reasonable local analogs
of distant Lyman break galaxies.Comment: 4 pages, 4 figures. To appear in "Starbursts: from 30 Doradus to
Lyman Break Galaxies" 2005, eds. R. de Grijs and R. M. Gonzalez Delgado
(Kluwer
Total Molecular Gas Masses of Planck - Herschel Selected Strongly Lensed Hyper Luminous Infrared Galaxies
We report the detection of CO(1 - 0) line emission from seven Planck and
Herschel selected hyper luminous (LIR(8-1000um) > 10^13Lsun) infrared galaxies
with the Green Bank Telescope (GBT). CO(1 - 0) measurements are a vital tool to
trace the bulk molecular gas mass across all redshifts. Our results place tight
constraints on the total gas content of these most apparently luminous high-z
star-forming galaxies (apparent IR luminosities of LIR > 10^(13-14) Lsun),
while we confirm their predetermined redshifts measured using the Large
Millimeter Telescope, LMT (zCO = 1.33 - 3.26). The CO(1 - 0) lines show similar
profiles as compared to Jup = 2 -4 transitions previously observed with the
LMT. We report enhanced infrared to CO line luminosity ratios of
= 110 (pm 22) Lsun(K km s^-1 pc^-2)^-1 compared to normal
star-forming galaxies, yet similar to those of well-studied IR-luminous
galaxies at high-z. We find average brightness temperature ratios of =
0.93 (2 sources), = 0.34 (5 sources), and = 0.18 (1 source). The
r31 and r41 values are roughly half the average values for SMGs. We estimate
the total gas mass content as uMH2 = (0.9 - 27.2) x 10^11(alphaCO/0.8)Msun,
where u is the magnification factor and alphaCO is the CO line luminosity to
molecular hydrogen gas mass conversion factor. The rapid gas depletion times
are, on average, tau = 80 Myr, which reveal vigorous starburst activity, and
contrast the Gyr depletion timescales observed in local, normal star-forming
galaxies.Comment: published in MNRAS, 9pages, 5fig
Minimum construction of two-qubit quantum operations
Optimal construction of quantum operations is a fundamental problem in the
realization of quantum computation. We here introduce a newly discovered
quantum gate, B, that can implement any arbitrary two-qubit quantum operation
with minimal number of both two- and single-qubit gates. We show this by giving
an analytic circuit that implements a generic nonlocal two-qubit operation from
just two applications of the B gate. We also demonstrate that for the highly
scalable Josephson junction charge qubits, the B gate is also more easily and
quickly generated than the CNOT gate for physically feasible parameters.Comment: 4 page
Switched Control of Electron Nuclear Spin Systems
In this article, we study control of electron-nuclear spin dynamics at
magnetic field strengths where the Larmor frequency of the nucleus is
comparable to the hyperfine coupling strength. The quantization axis for the
nuclear spin differs from the static B_0 field direction and depends on the
state of the electron spin. The quantization axis can be switched by flipping
the state of electron spin, allowing for universal control on nuclear spin
states. We show that by performing a sequence of flips (each followed by a
suitable delay), we can perform any desired rotation on the nuclear spins,
which can also be conditioned on the state of the electron spin. These
operations, combined with electron spin rotations can be used to synthesize any
unitary transformation on the coupled electron-nuclear spin system. We discuss
how these methods can be used for design of experiments for transfer of
polarization from the electron to the nuclear spins
Detection of a Substantial Molecular Gas Reservoir in a brightest cluster galaxy at z = 1.7
We report the detection of CO(2-1) emission coincident with the brightest
cluster galaxy (BCG) of the high-redshift galaxy cluster SpARCS1049+56, with
the Redshift Search Receiver (RSR) on the Large Millimetre Telescope (LMT). We
confirm a spectroscopic redshift for the gas of z = 1.7091+/-0.0004, which is
consistent with the systemic redshift of the cluster galaxies of z = 1.709. The
line is well-fit by a single component Gaussian with a RSR resolution-corrected
FWHM of 569+/-63 km/s. We see no evidence for multiple velocity components in
the gas, as might be expected from the multiple image components seen in
near-infrared imaging with the Hubble Space Telescope. We measure the
integrated flux of the line to be 3.6+/-0.3 Jy km/s and, using alpha_CO = 0.8
Msun (K km s^-1 pc^2)^-1 we estimate a total molecular gas mass of
1.1+/-0.1x10^11 Msun and a M_H2/M_star ~ 0.4. This is the largest gas reservoir
detected in a BCG above z > 1 to date. Given the infrared-estimated star
formation rate of 860+/-130 Msun/yr, this corresponds to a gas depletion
timescale of ~0.1Gyr. We discuss several possible mechanisms for depositing
such a large gas reservoir to the cluster center -- e.g., a cooling flow, a
major galaxy-galaxy merger or the stripping of gas from several galaxies -- but
conclude that these LMT data are not sufficient to differentiate between them.Comment: accepted for publication in ApJ Letter
Optical Morphologies of Millijansky Radio Galaxies Observed by HST and in the VLA FIRST Survey
We report on a statistical study of the 51 radio galaxies at the millijansky
flux level from the Faint Images of the Radio Sky at Twenty centimeters,
including their optical morphologies and structure obtained with the Hubble
Space Telescope. Our optical imaging is significantly deeper (~2 mag) than
previous studies with the superior angular resolution of space-based imaging.
We that find 8/51 (16%) of the radio sources have no optically identifiable
counterpart to AB~24 mag. For the remaining 43 sources, only 25 are
sufficiently resolved in the HST images to reliably assign a visual
classification: 15 (60%) are elliptical galaxies, 2 (8%) are late-type spiral
galaxies, 1 (4%) is an S0, 3 (12%) are point-like objects (quasars), and 4
(16%) are merger systems. We find a similar distribution of optical types with
measurements of the Sersic index. The optical magnitude distribution of these
galaxies peaks at I~20.7+-0.5 AB mag, which is ~3 mag brighter than the depth
of our typical HST field and is thus not due to the WFPC2 detection limit. This
supports the luminosity-dependent density evolutionary model, where the
majority of faint radio galaxies typically have L*-optical luminosities and a
median redshift of z~0.8 with a relatively abrupt redshift cut-off at z>~2. We
discuss our results in the context of the evolution of elliptical galaxies and
active galactic nuclei.Comment: 20 pages, 8 figures, 51 galaxy images, and 5 tables. Uses
emulateapj.cls and natbib.sty. Accepted to ApJS. High resolution images are
available upon reques
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