3,622 research outputs found
Home Front to War Front: The Navy Nurse Corps During World War II
The Navy Nurse Corps was created in 1908, when President Theodore Roosevelt signed the Naval Appropriations Bill. Twenty women were selected to become the corpsâ first members. These women were referred to as the âThe Sacred Twenty.â On December 7, 1941, when the Japanese bombed Pearl Harbor, the Navy Nurse Corps, was one of the first groups to respond. These women were important in preventing further deaths following the attack. However the experiences of Navy nurses during World II are often left untold because their story is overshadowed by the Army Nurse Corps, which doubled in size during the war. However, not one personâs experience is typical. This paper tells the stories of the women in the Navy Nurse Corps during World War II, through the experiences of Dora Cline Fechtmann, Dorothy Still Danner, Mary Rose âRedâ Harrington and other Navy nurses
Optimal control of circular cylinder wakes using long control horizons
The classical problem of suppressing vortex shedding in the wake of a
circular cylinder by using body rotation is revisited in an adjoint-based
optimal control framework. The cylinder's unsteady and fully unconstrained
rotation rate is optimized at Reynolds numbers between 75 and 200 and over
horizons that are longer than in previous studies, where they are typically of
the order of a vortex shedding period or shorter. In the best configuration,
the drag is reduced by 19%, the vortex shedding is effectively suppressed, and
this low drag state is maintained with minimal cylinder rotation after
transients. Unlike open-loop control, the optimal control is shown to maintain
a specific phase relationship between the actuation and the shedding in order
to stabilize the wake. A comparison is also given between the performance of
optimizations for different Reynolds numbers, cost functions, and horizon
lengths. It is shown that the long horizons used are necessary in order to
stabilize the vortex shedding efficiently
Final spin of a coalescing black-hole binary: an Effective-One-Body approach
We update the analytical estimate of the final spin of a coalescing
black-hole binary derived within the Effective-One-Body (EOB) approach. We
consider unequal-mass non-spinning black-hole binaries. It is found that a more
complete account of relevant physical effects (higher post-Newtonian accuracy,
ringdown losses) allows the {\it analytical} EOB estimate to `converge towards'
the recently obtained {\it numerical} results within 2%. This agreement
illustrates the ability of the EOB approach to capture the essential physics of
coalescing black-hole binaries. Our analytical approach allows one to estimate
the final spin of the black hole formed by coalescing binaries in a mass range
() which is not presently covered by numerical
simulations.Comment: 8 pages, two figures. To appear in Phys. Rev.
Comparing Effective-One-Body gravitational waveforms to accurate numerical data
We continue the program of constructing, within the Effective-One-Body (EOB)
approach, high accuracy, faithful analytic waveforms describing the
gravitational wave signal emitted by inspiralling and coalescing binary black
holes (BHs). We present the comparable-mass version of a new, resummed
3PN-accurate EOB quadrupolar waveform recently introduced in the
small-mass-ratio limit. We compare the phase and the amplitude of this waveform
to the recently published results of a high-accuracy numerical relativity (NR)
simulation of 15 orbits of an inspiralling equal-mass binary BHs system
performed by the Caltech-Cornell group. We find a remarkable agreement, both in
phase and in amplitude, between the new EOB waveform and the published
numerical data. More precisely: (i) in the gravitational wave (GW) frequency
domain where the phase of one of the non-resummed ``Taylor
approximant'' (T4) waveform matches well with the numerical relativity one, we
find that the EOB phase fares as well, while (ii) for higher GW frequencies,
, where the TaylorT4 approximant starts to
significantly diverge from the NR phase, we show that the EOB phase continues
to match well the NR one. We further propose various methods of tuning the two
inspiral flexibility parameters, and , of the EOB waveform
so as to ``best fit'' EOB predictions to numerical data. We find that the
maximal dephasing between EOB and NR can then be reduced below GW
cycles over the entire span (30 GW cycles) of the simulation. Our resummed EOB
amplitude agrees much better with the NR one than any of the previously
considered non-resummed, post-Newtonian one.Comment: 15 pages, 7 figures, submitted to Phys. Rev. D. Revised version.
Figs. 2-7 improved. Slight changes in a few numbers. One reference adde
Getting that Sinking Feeling: Analysis and Impacts of Sea Level Rise on Three National Parks along the East Coast, USA
Due to global climate change, sea level rise (SLR) has become a threat for future generations, but the extent of this danger is unknown. To help understand the possible effects of SLR on the east coast of the United States, we studied three national parks: Acadia National Park (ACAD), Assateague Island National Seashore (ASIS) and Everglades National Park (EVER). We predicted that ACAD would be less affected by SLR than ASIS and EVER due to the construction of its beach profile. By measuring the beach profile, we found that Sand Beach in ACAD was reflective with an average slope of 3.2 cm/m while South Ocean Beach in ASIS had an intermediate morphology with an average slope of 1.57 cm/m. The Snake Bight Channel beach in EVER was dissipative and had no slope. Using historical Landsat imagery from 1984 to 2016, we estimated that ACADâs water area increased by 1.61%, that ASISâs water area increased by 2.47%, and that the EVERâs water area decreased by 0.22% between 1992 and 2011. Using RCP scenarios from the latest IPCC report, we estimated future inundation levels in each park along with the percent change between the best and worst-case scenarios. Under the RCP8.5 scenario, ACAD had 1.36 km2 of inundation, ASIS had 37.11 km2, and EVER had 366.47 km2. ACAD had the highest percent change between the worst and best RCP scenario at 15.70%. ASIS had a slightly smaller percent change at 14.25% and EVER had even less at 10.42%. This study suggests that continued SLR will cause national parks billions of dollars in property damage and the loss of their inherent ecological value
Gravitational Self Force in a Schwarzschild Background and the Effective One Body Formalism
We discuss various ways in which the computation of conservative
Gravitational Self Force (GSF) effects on a point mass moving in a
Schwarzschild background can inform us about the basic building blocks of the
Effective One-Body (EOB) Hamiltonian. We display the information which can be
extracted from the recently published GSF calculation of the first-GSF-order
shift of the orbital frequency of the last stable circular orbit, and we
combine this information with the one recently obtained by comparing the EOB
formalism to high-accuracy numerical relativity (NR) data on coalescing binary
black holes. The information coming from GSF data helps to break the degeneracy
(among some EOB parameters) which was left after using comparable-mass NR data
to constrain the EOB formalism. We suggest various ways of obtaining more
information from GSF computations: either by studying eccentric orbits, or by
focussing on a special zero-binding zoom-whirl orbit. We show that logarithmic
terms start entering the post-Newtonian expansions of various (EOB and GSF)
functions at the fourth post-Newtonian (4PN) level, and we analytically compute
the first logarithm entering a certain, gauge-invariant "redshift" GSF function
(defined along the sequence of circular orbits).Comment: 44 page
Water immersion increases the concentration of the immunoreactive N-terminal fragment of pro-atrial natriuretic factor in human plasma
Atrial natriuretic factor (ANF) N-terminal (ANF 1â98) and C-terminal (ANF 99â126) fragments were determined by radioimmunoassay in human plasma. Mean basal plasma ANF N-terminal concentrations in 9 healthy subjects were 461 ± 58 fmol/ml,significantly (p<0.0001) higher than ANF C-terminal concentrations ( 4.8 ± 0.5 fmol/ml). Central volume stimulation by one hour head-out water immersion (WI) induced a significant (p<0.01) increase of the C-terminal peptide levels to 11.6 ± 2.3 fmol/ml,paralleled by a significant (p<0.001) increase of the N-terminal fragment levels to 749 ± 96 fmol/ml. Increases of plasma concentrations of both fragments upon WI correlated significantly (r=0.71;p<0.05). These data suggest cosecretion of the N-terminal fragment with the C-terminal fragment of pro ANF 1â126 following a physiological stimulus of ANF release in man
Recommended from our members
Women, Convergent Film Criticism, and the Cinephilia of Feminist Interruptions
This dissertation examines the ways in which female film critics practice film criticism in the convergent age. In original research drawn from ethnographic interviews with eight female film critics and bloggers as well as textual, historical, and reception analyses of criticism, this dissertation argues that women who write film criticism in the convergent era are not only writing from a space of marginalization based on the patriarchal dominance of the film industry, but also face a series of obstacles through gendered and discursive conflicts that are unique to writing online and which do not exert the same impact on male film critics. The findings reveal that women often draw on a feminist impulse to disrupt critical film discourse. I deem this disruption the âcinephilia of feminist interruptionsââa space where women who are knowledgeable about cinema must address issues of representation, identity, misogyny or sexism that interrupt the pleasure of moviegoing and their own writing practice. Women writing film criticism today not only must fight for cultural authority but must defend their knowledge of film, their feminist approach to film and media, and be constantly aware of how the simple fact of their gender shapes how male critics and audiences will receive their criticism
Electromagnetic flow control: characteristic numbers and flow regimes of a wall-normal actuator
Accepted versio
- âŠ