2,829 research outputs found
Men nurses: job opportunities in nursing
Thesis (M.S.)--Boston Universit
Pirates for Academic Success
ECU reported in 2019 that the school had an overall retention rate of 83%. Although this percentage seems high, it is nothing compared to UNC Chapel Hill’s overall retention rate of 97.2% or Duke’s rate of 97.6%, (both reported from 2013-2017.) Because of this our group decided to research why ECU’s retention rate was so much lower than surrounding universities and provide resources and information to take a step forward in solving these problems. After spending our first year conducting interviews among students, it was clear that most students were not aware of the resources offered to them on campus. Some were not even aware of their style of learning and how to effectively study for upcoming exams or quizzes. From this we created Pirates for Academic Success. Our goal was to make videos explaining not only what resources were available on campus that you may not know about but also explain different studying techniques and how discovering your style of learning can lead to a more effective study pattern. Doing this allows students who do not know ECU campus that well or who do not know many other students a way to find resources in a less intimidating way. This can lead to higher grades, more confidence in coursework and classes, and a higher chance of students staying at ECU for a second year. “Confident students develop relationships with faculty that can lead to participation in research and other developmental activities...this leads further to potential future connections, letters of recommendation, internships, future work, or graduate school� (Croskey, 2021). Our group has set up a Vimeo containing videos ranging from how to use different online homework platforms such as Cengage to resources at the library students may not be aware of and how to effectively use them. Through this we have established a relationship with the library, marketing our videos and receiving exclusive access to the library to make more videos using their equipment
Making adaptable systems work for mission operations: A case study
The Advanced Multimission Operations System (AMMOS) at NASA's Jet Propulsion Laboratory is based on a highly adaptable multimission ground data system (MGDS) for mission operations. The goal for MGDS is to support current flight project science and engineering personnel and to meet the demands of future missions while reducing associated operations and software development costs. MGDS has become a powerful and flexible mission operations system by using a network of heterogeneous workstations, emerging open system standards, and selecting an adaptable tools-based architecture. Challenges in developing adaptable systems for mission operations and the benefits of this approach are described
Effective interactions in the colloidal suspensions from HNC theory
The HNC Ornstein-Zernike integral equations are used to determine the
properties of simple models of colloidal solutions where the colloids and ions
are immersed in a solvent considered as a dielectric continuum and have a size
ratio equal to 80 and a charge ratio varying between 1 and 4000. At an infinite
dilution of colloids, the effective interactions between colloids and ions are
determined for ionic concentrations ranging from 0.001 to 0.1 mol/l and
compared to those derived from the Poisson-Boltzmann theory. At finite
concentrations, we discuss on the basis of the HNC results the possibility of
an unambiguous definition of the effective interactions between the colloidal
molecules.Comment: 26 pages, 15 figure
The Stellar Ages and Masses of Short GRB Host Galaxies: Investigating the Progenitor Delay Time Distribution and the Role of Mass and Star Formation in the Short GRB Rate
[Abridged] We present optical and NIR observations of 19 short GRB host
galaxies, aimed at measuring their stellar masses and population ages. The
goals of this study are to evaluate whether short GRBs track the stellar mass
distribution of galaxies, to investigate the progenitor delay time
distribution, and to explore any connection between long and short GRB
progenitors. Using single stellar population models we infer masses of
log(M/M_sun)=8.8-11.6 and population ages of tau=0.03-4.4 Gyr. We further infer
maximal masses of log(M/M_sun)=9.7-11.9 by assuming stellar population ages
equal to the age of the universe at each host's redshift. Comparing the
distribution of stellar masses to the general galaxy mass function we find that
short GRBs track the cosmic stellar mass distribution only if the late-type
hosts generally have maximal masses. However, there is an apparent dearth of
early-type hosts compared to the equal contribution of early- and late-type
galaxies to the cosmic stellar mass budget. These results suggest that stellar
mass may not be the sole parameter controlling the short GRB rate, and raise
the possibility of a two-component model with both mass and star formation
playing a role. If short GRBs in late-type galaxies indeed track the star
formation activity, the resulting typical delay time is ~0.2 Gyr, while those
in early-type hosts have a typical delay of ~3 Gyr. Using the same stellar
population models we fit the data for 22 long GRB hosts and find that they have
lower masses and younger population ages, with =9.1 and
=0.06 Gyr, respectively; their maximal masses are similarly lower,
=9.6. Most importantly, the two host populations remain distinct
even if we consider only the star-forming hosts of short GRBs, supporting our
previous findings that the progenitors of long GRBs and short GRBs in late-type
galaxies are distinct.Comment: Submitted to ApJ; 20 pages, 3 tables, 8 figure
The answer is blowing in the wind: Simulating the interaction of jets with dynamic cluster atmospheres
We present numerical simulations investigating the interaction of AGN jets
with galaxy clusters, for the first time taking into account the dynamic nature
of the cluster gas and detailed cluster physics. The simulations successfully
reproduce the observed morphologies of radio sources in clusters. We find that
cluster inhomogeneities and large scale flows have significant impact on the
morphology of the radio source and cannot be ignored a-priori when
investigating radio source dynamics. Morphological comparison suggests that the
gas in the centres of clusters like Virgo and Abell 4059 shows significant
shear and/or rotation. We find that shear and rotation in the intra-cluster
medium move large amounts of cold material back into the path of the jet,
ensuring that subsequent jet outbursts encounter a sufficient column density of
gas to couple with the inner cluster gas, thus alleviating the problem of
evacuated channels discussed in the recent literature. The same effects
redistribute the excess energy Delta_E deposited by the jets, making the
distribution of Delta_E at late times consistent with being isotropic.Comment: 5 Pages, 5 figures, submitted to MNRAS Letter
The impact of mass-loss on the evolution and pre-supernova properties of red supergiants
The post main-sequence evolution of massive stars is very sensitive to many
parameters of the stellar models. Key parameters are the mixing processes, the
metallicity, the mass-loss rate and the effect of a close companion. We study
how the red supergiant lifetimes, the tracks in the Hertzsprung-Russel diagram
(HRD), the positions in this diagram of the pre-supernova progenitor as well as
the structure of the stars at that time change for various mass-loss rates
during the red supergiant phase (RSG), and for two different initial rotation
velocities. The surface abundances of RSGs are much more sensitive to rotation
than to the mass-loss rates during that phase. A change of the RSG mass-loss
rate has a strong impact on the RSG lifetimes and therefore on the luminosity
function of RSGs. At solar metallicity, the enhanced mass-loss rate models do
produce significant changes on the populations of blue, yellow and red
supergiants. When extended blue loops or blue ward excursions are produced by
enhanced mass-loss, the models predict that a majority of blue (yellow)
supergiants are post RSG objects. These post RSG stars are predicted to show
much smaller surface rotational velocities than similar blue supergiants on
their first crossing of the HR gap. The position in the HRD of the end point of
the evolution depends on the mass of the hydrogen envelope. More precisely,
whenever, at the pre-supernova stage, the H-rich envelope contains more than
about 5\% of the initial mass, the star is a red supergiant, and whenever the
H-rich envelope contains less than 1\% of the total mass the star is a blue
supergiant. For intermediate situations, intermediate colors/effective
temperatures are obtained. Yellow progenitors for core collapse supernovae can
be explained by the enhanced mass-loss rate models, while the red progenitors
are better fitted by the standard mass-loss rate models.Comment: 19 pages, 11 figures, 6 tables, accepted for publication in Astronomy
and Astrophysic
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