1,837 research outputs found
Pancreatoscopy-guided electrohydraulic lithotripsy in a patient with calcific chronic pancreatitis
info:eu-repo/semantics/publishedVersio
Nonlinear effect on modal data analysis method
How the presence of nonlinearities in structural test data can be detected when using modern linear modal data analysis methods is discussed. The extent to which linear algorithms can provide useful information on nonlinear systems was discussed. The modal data analysis method successfully identified the frequency components (but not damping) of the true solution of a nonlinear systems. It was found that the approximate modal parameters of the linear system can be identified by the modal method when low levels of nonlinearities are present. The modal method successfully identified the modal parameters of a linear mode in the presence of a nonlinear response
Initial test results for the mini-mast
The objectives of the 20-meter Mini-Mast were: (1) to learn how to efficiently test this type of large truss structure, (2) to relate component testing to the overall behavior of the structure, and (3) to update the associated analytical model based upon the experimental data. The Mini-Mast represents structural characteristics similar to the COFS beam which is planned to be flown on Shuttle to perform on-orbit structures and controls experiments. The information is of interest to LDR because it represents analysis and test information on a truss-type structure which may be similar to the Large Deployable Reflector (LDR) backup structure. The structure has a total of 111 titanium joints; the joint in the center of the truss element is a near-center latch joint. The results of this research indicate that linear deployable-type structures can be built, but difficulties do exist in extracting modes with identical frequencies; gravitational loading does affect the ground test results; and prediction of truss-type-structure dynamic characteristics is not trivial
Eosinophilic Ascites: Uncommon Presentation of Eosinophilic Gastroenteritis in a Young Adult Male.
info:eu-repo/semantics/publishedVersio
Multifrequency radio observations of SNR J0536-6735 (N 59B) with associated pulsar
We present a study of new Australian Telescope Compact Array (ATCA)
observations of supernova remnant, SNR J0536-6735. This remnant appears to
follow a shell morphology with a diameter of D=36x29 pc (with 1 pc uncertainty
in each direction). There is an embedded Hii region on the northern limb of the
remnant which made various analysis and measurements (such as flux density,
spectral index and polarisation) difficult. The radio-continuum emission
followed the same structure as the optical emission, allowing for extent and
flux density estimates at 20 cm. We estimate a surface brightness for the SNR
at 1 GHz of 2.55x10^-21 W m^-2 Hz^-1 sr^-1. Also, we detect a distinctive
radio-continuum point source which confirms the previous suggestion of this
remnant being associated with a pulsar wind nebulae (PWN). The tail of this
remnant isn't seen in the radio-continuum images and is only seen in the
optical and X-ray images.Comment: 10 pages 4 figures, accepted for publication in SA
Multi-frequency study of Local Group Supernova Remnants The curious case of the Large Magellanic Cloud SNR J0528-6714
Aims. Recent ATCA, XMM-Newton and MCELS observations of the Magellanic Clouds
(MCs) cover a number of new and known SNRs which are poorly studied, such as
SNR J0528-6714 . This particular SNR exhibits luminous radio-continuum
emission, but is one of the unusual and rare cases without detectable optical
and very faint X-ray emission (initially detected by ROSAT and listed as object
[HP99] 498). We used new multi-frequency radio-continuum surveys and new
optical observations at H{\alpha}, [S ii] and [O iii] wavelengths, in
combination with XMM-Newton X-ray data, to investigate the SNR properties and
to search for a physical explanation for the unusual appearance of this SNR.
Methods. We analysed the X-ray and Radio-Continuum spectra and present
multi-wavelength morphological studies of this SNR.
Results. We present the results of new moderate resolution ATCA observations
of SNR J0528-6714. We found that this object is a typical older SNR with a
radio spectral index of {\alpha}=-0.36 \pm 0.09 and a diameter of D=52.4 \pm
1.0 pc. Regions of moderate and somewhat irregular polarisation were detected
which are also indicative of an older SNR. Using a non-equilibrium ionisation
collisional plasma model to describe the X-ray spectrum, we find temperatures
kT of 0.26 keV for the remnant. The low temperature, low surface brightness,
and large extent of the remnant all indicate a relatively advanced age. The
near circular morphology indicates a Type Ia event.
Conclusions. Our study revealed one of the most unusual cases of SNRs in the
Local Group of galaxies - a luminous radio SNR without optical counterpart and,
at the same time, very faint X-ray emission. While it is not unusual to not
detect an SNR in the optical, the combination of faint X-ray and no optical
detection makes this SNR very unique.Comment: 6 pages, 5 figures, Accepted for publication in A&
Multifrequency Radio Observations of a SNR in the LMC. The Case of SNR J0527-6549 (DEM l204)
We present a detailed study and results of new Australia Telescope Compact
Array (ATCA) observations of supernova remnant, SNR J0527-6549. This Large
Magellanic Cloud (LMC) ob ject follows a typical supernova remnant (SNR)
horseshoe morphology with a diameter of D=(66x58)+-1 pc which is among the
largest SNRs in the LMC. Its relatively large size indicates older age while a
steeper than expected radio spectral index of aplha=-0.92+-0.11 is more typical
for younger and energetic SNRs. Also, we report detections of regions with a
high order of polarization at a peak value of ~54+-17% at 6 cm.Comment: 9 Pages, 6 figures, accepted for publication in SA
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