3,589 research outputs found
Factors in the Admissions Process Influencing Persistence in a Master’s of Science Program in Marine Science
Factors in the Admissions Process Influencing Persistence in a Master’s of Science Program in Marine Science. Melissa L. Dore, 2017: Applied Dissertation, Nova Southeastern University, Abraham S. Fischler College of Education. Keywords: academic persistence, admission counseling, graduate students, marine science education, examinations This applied dissertation was conducted to provide the graduate program in marine sciences a valid predictor for success in the admissions scoring systems that include the general Graduate Record Exam. The dependent variable was persistence: successfully graduating from the marine sciences master’s programs. This dissertation evaluated other values including the applicant’s age, gender, undergraduate GPA, letters of recommendation, and acceptance level (Accepted with Academic Requirement (probation) or Full Acceptance). The writer statistically showed that two values proved most significant in defining a student’s persistence: undergraduate major GPA and age when entering the program. An analysis of the data allowed the marine science master’s programs to develop an index to assist students to succeed in the program as well as reduce the time to completion
What to Do With Omar Khadr? Putting a Child Soldier on Trial: Questions of International Law, Juvenile Justice, and Moral Culpability, 41 J. Marshall L. Rev. 1281 (2008)
Recognition of Rhodesia and Traditional International Law: Some Conceptual Problems
The traditional theories of recognition do not properly maintain the essential distinction between state and government. The only proper way to maintain this distinction is by laying down verifiable criteria for statehood, and treating the recognition of governments as purely discretionary. A state must have come into existence before the question of recognition of a particular government can arise. International personality is a consequence of statehood, not of recognition; if a state can objectively come into existence, so can international personality, and the grant or withdrawal of recognition cannot affect that personality.
The degree of recognition conferred by the United Kingdom and other countries on Rhodesia on various occasions was limited in scope, purpose, and time, and was not indicative of any opinion that the Smith government or the Smith/Muzorewa government was the legitimate government of Rhodesia; nor did such qualified recognition demonstrate any intention to have normal relations with Rhodesia. It would seem proper to view this as a question of recognition of a de facto governing authority. Rhodesia must, therefore, be regarded as a state with international legal personality. As such, it is bound by international law, like any other state, and is subject to the usual range of penal sanctions available to the international community to counter any breach of international law
Freezing Out Early Dark Energy
A phenomenological model of dark energy that tracks the baryonic and cold
dark matter at early times but resembles a cosmological constant at late times
is explored. In the transition between these two regimes, the dark energy
density drops rapidly as if it were a relic species that freezes out, during
which time the equation of state peaks at +1. Such an adjustment in the dark
energy density, as it shifts from scaling to potential-domination, could be the
signature of a trigger mechanism that helps explain the late-time cosmic
acceleration. We show that the non-negligible dark energy density at early
times, and the subsequent peak in the equation of state at the transition,
leave an imprint on the cosmic microwave background anisotropy pattern and the
rate of growth of large scale structure. The model introduces two new
parameters, consisting of the present-day equation of state and the redshift of
the freeze-out transition. A Monte Carlo Markov Chain analysis of a
ten-dimensional parameter space is performed to compare the model with
pre-Planck cosmic microwave background, large scale structure and supernova
data and measurements of the Hubble constant. We find that the transition
described by this model could have taken place as late as a redshift z~400. We
explore the capability of future cosmic microwave background and weak lensing
experiments to put tighter constraints on this model. The viability of this
model may suggest new directions in dark-energy model building that address the
coincidence problem.Comment: 11 pages, 15 figure
Detection of N15NH+ in L1544
Excess levels of 15N isotopes which have been detected in primitive solar
system materials are explained as a remnant of interstellar chemistry which
took place in regions of the protosolar nebula. Chemical models of nitrogen
fractionation in cold clouds predict an enhancement in the gas-phase abundance
of 15N-bearing molecules, thus we have searched for 15N variants of the N2H+
ion in L1544, which is one of the best candidate sources for detection owing to
its low central core temperature and high CO depletion. With the IRAM 30m
telescope we have obtained deep integrations of the N2H+(1-0) line at 91.2 GHz.
The N2H+(1-0) line has been detected toward the dust emission peak of L1544.
The 14N/15N abundance ratio in N2H+ resulted 446+/-71, very close to the
protosolar value of ~450, higher than the terrestrial ratio of ~270, and
significantly lower than the lower limit in L1544 found by Gerin et al. (2009,
ApJ, 570, L101) in the same object using ammonia isotopologues.Comment: Accepted for publication in Astronomy and Astrophysic
A combined experimental and computational study of the pressure dependence of the vibrational spectrum of solid picene C_22H_14
We present high-quality optical data and density functional perturbation
theory calculations for the vibrational spectrum of solid picene
(CH) under pressure up to 8 GPa. First-principles calculations
reproduce with a remarkable accuracy the pressure effects on both frequency and
intensities of the phonon peaks experimentally observed . Through a detailed
analysis of the phonon eigenvectors, We use the projection on molecular
eigenmodes to unambiguously fit the experimental spectra, resolving complicated
spectral structures, in a system with hundreds of phonon modes. With these
projections, we can also quantify the loss of molecular character under
pressure. Our results indicate that picene, despite a \sim 20 % compression of
the unit cell, remains substantially a molecular solid up to 8 GPa, with phonon
modes displaying a smooth and uniform hardening with pressure. The Grueneisen
parameter of the 1380 cm^{-1} a_1 Raman peak () is much lower
than the effective value () due to K doping. This is an
indication that the phonon softening in K doped samples is mainly due to charge
transfer and electron-phonon coupling.Comment: Replaced with final version (PRB
Far infrared properties of the rare-earth scandate DyScO3
We present reflectance measurements in the infrared region on a single
crystal the rare earth scandate DyScO3. Measurements performed between room
temperature and 10 K allow to determine the frequency of the infrared-active
phonons, never investigated experimentally, and to get information on their
temperature dependence. A comparison with the phonon peak frequency resulting
from ab-initio computations is also provided. We finally report detailed data
on the frequency dependence of the complex refractive index of DyScO3 in the
terahertz region, which is important in the analysis of terahertz measurements
on thin films deposited on DyScO3
Vibrational spectrum of solid picene (C_22H_14)
Recently, Mitsuhashi et al., have observed superconductivity with transition
temperature up to 18 K in potassium doped picene (C22H14), a polycyclic
aromatic hydrocarbon compound [Nature 464 (2010) 76]. Theoretical analysis
indicate the importance of electron-phonon coupling in the superconducting
mechanisms of these systems, with different emphasis on inter- and
intra-molecular vibrations, depending on the approximations used. Here we
present a combined experimental and ab-initio study of the Raman and infrared
spectrum of undoped solid picene, which allows us to unanbiguously assign the
vibrational modes. This combined study enables the identification of the modes
which couple strongly to electrons and hence can play an important role in the
superconducting properties of the doped samples
Molecular ions in L1544. I. Kinematics
We have mapped the dense dark core L1544 in H13CO+(1-0), DCO+(2-1),
DCO+(3-2), N2H+(1-0), NTH+(3-2), N2D+(2-1), N2D+(3-2), C18O(1-0), and C17O(1-0)
using the IRAM 30-m telescope. We have obtained supplementary observations of
HC18O+(1-0), HC17O+(1-0), and D13CO+(2-1). Many of the observed maps show a
general correlation with the distribution of dust continuum emission in
contrast to C18O(1-0) and C17O(1-0) which give clear evidence for depletion of
CO at positions close to the continuum peak. In particular N2D+(2-1) and (3-2)
and to a lesser extent N2H+(1-0) appear to be excellent tracers of the dust
continuum. We find that the tracers of high density gas (in particular N2D+)
show a velocity gradient along the minor axis of the L1544 core and that there
is evidence for larger linewidths close to the dust emission peak. We interpret
this using the model of the L1544 proposed by Ciolek & Basu (2000) and by
comparing the observed velocities with those expected on the basis of their
model. The results show reasonable agreement between observations and model in
that the velocity gradient along the minor axis and the line broadening toward
the center of L1544 are predicted by the model. This is evidence in favour of
the idea that amipolar diffusion across field lines is one of the basic
processes leading to gravitational collapse. However, line widths are
significantly narrower than observed and are better reproduced by the Myers &
Zweibel (2001) model which considers the quasistatic vertical contraction of a
layer due to dissipation of its Alfvenic turbulence, indicating the importance
of this process for cores in the verge of forming a star.Comment: 24 pages, 9 figures, to be published in Ap
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