3,508 research outputs found
Nongassing NiCd battery cell
Method of constructing nickel cadmium batteries prevents excessive gas buildup and allows hermetic sealing of battery for increased service life and reduced maintenance cost
Chandra observations of the HII complex G5.89-0.39 and TeV gamma-ray source HESSJ1800-240B
We present the results of our investigation, using a Chandra X-ray
observation, into the stellar population of the massive star formation region
G5.89-0.39, and its potential connection to the coincident TeV gamma-ray source
HESSJ1800-240B. G5.89-0.39 comprises two separate HII regions G5.89-0.39A and
G5.89-0.39B (an ultra-compact HII region). We identified 159 individual X-ray
point sources in our observation using the source detection algorithm
\texttt{wavdetect}. 35 X-ray sources are associated with the HII complex
G5.89-0.39. The 35 X-ray sources represent an average unabsorbed luminosity
(0.3-10\,keV) of \,erg/s, typical of B7-B5 type stars. The
potential ionising source of G5.89-0.39B known as Feldt's star is possibly
identified in our observation with an unabsorbed X-ray luminosity suggestive of
a B7-B5 star. The stacked energy spectra of these sources is well-fitted with a
single thermal plasma APEC model with kT5\,keV, and column density
N\,cm (A). The residual
(source-subtracted) X-ray emission towards G5.89-0.39A and B is about 30\% and
25\% larger than their respective stacked source luminosities. Assuming this
residual emission is from unresolved stellar sources, the total
B-type-equivalent stellar content in G5.89-0.39A and B would be 75 stars,
consistent with an earlier estimate of the total stellar mass of hot stars in
G5.89-0.39. We have also looked at the variability of the 35 X-ray sources in
G5.89-0.39. Ten of these sources are flagged as being variable. Further studies
are needed to determine the exact causes of the variability, however the
variability could point towards pre-main sequence stars. Such a stellar
population could provide sufficient kinetic energy to account for a part of the
GeV to TeV gamma-ray emission in the source HESSJ1800-240B.Comment: 34 pages, 9 figure
Inverse scattering method for square matrix nonlinear Schr\"odinger equation under nonvanishing boundary conditions
Matrix generalization of the inverse scattering method is developed to solve
the multicomponent nonlinear Schr\"odinger equation with nonvanishing boundary
conditions. It is shown that the initial value problem can be solved exactly.
The multi-soliton solution is obtained from the Gel'fand--Levitan--Marchenko
equation.Comment: 25 pages, 2 figures; (v2) title changed, typos in equations
corrected, sec.3.1 modified and extende
Constraints on cosmic-ray efficiency in the supernova remnant RCW 86 using multi-wavelength observations
Several young supernova remnants (SNRs) have recently been detected in the
high-energy and very-high-energy gamma-ray domains. As exemplified by RX
J1713.7-3946, the nature of this emission has been hotly debated, and direct
evidence for the efficient acceleration of cosmic-ray protons at the SNR shocks
still remains elusive. We analyzed more than 40 months of data acquired by the
Large Area Telescope (LAT) on-board the Fermi Gamma-Ray Space Telescope in the
HE domain, and gathered all of the relevant multi-wavelength (from radio to VHE
gamma-rays) information about the broadband nonthermal emission from RCW 86.
For this purpose, we re-analyzed the archival X-ray data from the ASCA/Gas
Imaging Spectrometer (GIS), the XMM-Newton/EPIC-MOS, and the RXTE/Proportional
Counter Array (PCA). Beyond the expected Galactic diffuse background, no
significant gamma-ray emission in the direction of RCW 86 is detected in any of
the 0.1-1, 1-10 and 10-100 GeV Fermi-LAT maps. In the hadronic scenario, the
derived HE upper limits together with the HESS measurements in the VHE domain
can only be accommodated by a spectral index Gamma <= 1.8, i.e. a value
in-between the standard (test-particle) index and the asymptotic limit of
theoretical particle spectra in the case of strongly modified shocks. The
interpretation of the gamma-ray emission by inverse Compton scattering of high
energy electrons reproduces the multi-wavelength data using a reasonable value
for the average magnetic field of 15-25 muG. For these two scenarios, we
assessed the level of acceleration efficiency. We discuss these results in the
light of existing estimates of the magnetic field strength, the effective
density and the acceleration efficiency in RCW 86.Comment: Accepted for publication in A&A; 10 pages and 4 figure
Age and growth of swordfish (Xiphias gladius) caught by the Hawaii-based pelagic longline fishery
We verified the age and growth of swordfish (Xiphias gla-dius) by comparing ages determined from annuli in fin ray sections with daily growth increments in otoliths. Growth of swordfish of exploitable sizes is described on the basis of annuli present in cross sections of the second ray of the first anal fins of 1292 specimens (60â260 cm eye-to-fork length, EFL) caught in the region of the Hawaii-based pelagic longline fishery. The position of the initial fin ray annulus of swordfish was verified for the first time with the use of scanning electron micrographs of presumed daily growth increments present in the otoliths of juveniles. Fish growth through age 7 was validated by marginal increment analysis. Faster growth of females was confirmed, and the standard von Bertalanffy growth model was
identified as the most parsimonious for describing growth in length for fish greater than 60 cm EFL. The observed growth of three fish, a year-old in size when first caught and then recaptured from 364 to1490 days later, is consistent with modeled growth for fish of this size range. Our novel approach to verifying age and growth should increase confidence in conducting an age-structured stock assessment for swordfish in the North Pacific Ocean
Pulse Control of Decoherence in a Qubit Coupled with a Quantum Environment
We study the time evolution of a qubit linearly coupled with a quantum
environment under a sequence of short pi pulses. Our attention is focused on
the case where qubit-environment interactions induce the decoherence with
population decay. We assume that the environment consists of a set of bosonic
excitations. The time evolution of the reduced density matrix for the qubit is
calculated in the presence of periodic short pi pulses. We confirm that the
decoherence is suppressed if the pulse interval is shorter than the correlation
time for qubit-environment interactions.Comment: 5 pages, 2figure
Gamma ray emission from SNR RX J1713.7-3946 and the origin of galactic cosmic rays
We calculate the flux of non-thermal radiations from the supernova remnant RX
J1713.7-3946 in the context of the non-linear theory of particle acceleration
at shocks, which allows us to take into account self-consistently the dynamical
reaction of the accelerated particles, the generation of magnetic fields in the
shock proximity and the dynamical reaction of the magnetic field on the plasma.
When the fraction of particles which get accelerated is of order , we find that the strength of the magnetic field obtained as a result
of streaming instability induced by cosmic rays is compatible with the
interpretation of the X-ray emitting filaments being produced by strong
synchrotron losses in magnetic fields. If the X-ray filaments
are explained in alternative ways, the constraint on the magnetic field
downstream of the shock disappears and the HESS data can be marginally fit with
ICS of relativistic electrons off a complex population of photons, tailored to
comprise CMB and ambient IR/Optical photons. The fit, typically poor at the
highest energies, requires a large density of target photons within the
remnant; only a fraction of order of the background particles
gets accelerated; the local magnetic field is of order and the
maximum energy of protons is much lower than the knee energy. Current HESS
gamma ray observations combined with recent X-ray observations by Suzaku do not
allow as yet to draw a definitive conclusion on whether RX J1713.7-3946 is an
efficient cosmic ray accelerator, although at the present time a hadronic
interpretation of HESS data seems more likely. We discuss the implications of
our results for the GLAST gamma ray telescope, which should be able to
discriminate the two scenarios discussed above.Comment: Accepted for Publication in MNRA
Topological-charge anomalies in supersymmetric theories with domain walls
Domain walls in 1+2 dimensions are studied to clarify some general features
of topological-charge anomalies in supersymmetric theories, by extensive use of
a superfield supercurrent. For domain walls quantum modifications of the
supercharge algebra arise not only from the short-distance anomaly but also
from another source of long-distance origin, induced spin in the domain-wall
background, and the latter dominates in the sum. A close look into the
supersymmetric trace identity, which naturally accommodates the central-charge
anomaly and its superpartners, shows an interesting consequence of the
improvement of the supercurrent: Via an improvement the anomaly in the central
charge can be transferred from induced spin in the fermion sector to an induced
potential in the boson sector. This fact reveals a dual character, both
fermionic and bosonic, of the central-charge anomaly, which reflects the
underlying supersymmetry. The one-loop superfield effective action is also
constructed to verify the anomaly and BPS saturation of the domain-wall
spectrum.Comment: 8 pages, Revte
Probing the Pulsar Wind in the gamma-ray Binary System PSR B1259-63/SS 2883
The spectral energy distribution from the X-ray to the very high energy
regime ( GeV) has been investigated for the -ray binary system
PSR B1259-63/SS2883 as a function of orbital phase within the framework of a
simple model of a pulsar wind nebula. The emission model is based on the
synchrotron radiation process for the X-ray regime and the inverse Compton
scattering process boosting stellar photons from the Be star companion to the
very high energy (100GeV-TeV) regime. With this model, the observed temporal
behavior can, in principle, be used to probe the pulsar wind properties at the
shock as a function of the orbital phase. Due to theoretical uncertainties in
the detailed microphysics of the acceleration process and the conversion of
magnetic energy into particle kinetic energy, the observed X-ray data for the
entire orbit are fit using two different methods.Comment: 46 pages, 16 figures, accepted for publication in Ap
Using a Hybrid Lecture and Small Group Standardized Patient Case to Teach the Inclusive Sexual History and Transgender Patient Care
Background: Previous negative experiences with the medical community often leave transgender people reluctant to seek needed medical treatment and preventive care. Inadequate training in transgender healthcare during all stages of medical education promotes the disparities experienced by this community. Undergraduate medical education is uniquely positioned to address these disparities by better preparing future physicians to provide inclusive care to transgender patients; however, curricular coverage of these topics remains inadequate.
Methods: The second-year clinical skills course at the Herbert Wertheim College of Medicine includes a hybrid workshop consisting of a one-hour lecture about the components of an inclusive sexual history, followed by a 1.5 hour, faculty-facilitated small group session during which students interview a standardized patient playing the role of a transgender man with abdominal pain. During the session, students were provided with an optional, anonymous pre- and post-intervention survey assessing the impact of this workshop.
Results: After the session, there was a statistically significant increase in studentsâ knowledge of the Create your own automated PDFs with JotForm PDF Editor 1 components of an inclusive sexual history, in the number of students who felt that their medical training had effectively prepared them to provide medical care for transgender patients, and in those who reported feeling comfortable gathering a sexual history from a transgender patient. Students overall reported a high level of satisfaction with the session and the standardized patient case.
Conclusions: Our findings suggest that the hybrid-learning format of the sexual history workshop effectively improved studentsâ knowledge and confidence regarding transgender healthcare and sexual history taking. Although our case was acted by well-coached cis-gender standardized patients without the lived experiences of being transgender, students still reported that it provided a realistic opportunity to explore the nuances of transgender healthcare. While we demonstrated value in using cis-gender standardized patients, future directions of this project will explore the recruitment of transgender standardized patients.https://jdc.jefferson.edu/sexandgenderhealth/1027/thumbnail.jp
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