178 research outputs found
Effect of electroless coating parameters and ceramic particle size on fabrication of a uniform NiâP coating on SiC particles
The formation of a uniform nickel phosphorous (NiâP) electroless (EL) coating on micronsized SiC particles was investigated in this study. Metal coated ceramic particles could be used in applications including as the fabrication of cast metal matrix composites.Such ceramic particles have a better wettability in molten metal. In this work, the effects of EL coating parameters, SiC particle size and morphology on the coating uniformity and mechanical bonding at the SiC/NiâP interface were studied. The results indicated that etching treatment was very effective (especially for coarse powders) on the mechanical bonding at the interface. Theoptimum values of bath temperature and pH were determined to be 50+_2 0C and 8+_0.2, respectively. The best uniformity and mechanical bonding were obtained for SiC particles with average particle size of 80 ÎŒm (considered relatively as coarse powders in this study). The ball milling of SiC particles (with the average particle size of 80 ÎŒm) for 1 h led to the formation of a multi-modal particle size distribution which resulted in a non-uniform quality of particulate coating. The larger SiC particles after ball milling were more completely covered by the NiâP coating compared to the smaller more fragmented particles. The smaller ceramic particles processed via NiâP EL coating lead to formation of segregated clusters of NiâP and therefore such ceramic particles contained many uncoated parts
Acute Disseminated Encephalomyelitis in A 5-Month Old Infant
AbstractObjectiveThis article reports on an 5-month-old infant who was admitted to our hospital for prolonged fever, focal status epilepticus and encephalopathy.Brain magnetic resonance imaging (MRI) demonstrated a single hyperintense lesion in right putamen in T2-weighted images.A diagnosis of acute disseminated encephalomyelitis was made based on the clinical features, treatment response and clinical course. An executive literature review revealed a few cases under the age of one year .This patient is the youngest are who is reported from Iran
A near infrared photometric plane for ellipticals and bulges of spirals
We report the existence of a single plane in the space of global photometric
parameters describing elliptical galaxies and the bulges of early type spiral
galaxies. The three parameters which define the plane are obtained by fitting
the Sersic form to the brightness distribution obtained from near-infrared K
band images. We find, from the range covered by their shape parameters, that
the elliptical galaxies form a more homogeneous population than the bulges.
Known correlations like the Kormendy relation are projections of the
photometric plane. The existence of the plane has interesting implications for
bulge formation models.Comment: 12 pages, LaTeX including 5 figures. To appear in the Astrophysical
Journal Letter
Development of an IgG4-RD Responder Index
IgG4-related disease (IgG4-RD) is a multiorgan inflammatory disease in which diverse organ manifestations are linked by common histopathological and immunohistochemical features. Prospective studies of IgG4-RD patients are required to clarify the natural history, long-term prognosis, and treatment approaches in this recently recognized condition. Patients with IgG4-RD have different organ manifestations and are followed by multiple specialties. Divergent approaches to the assessment of patients can complicate the interpretation of studies, emphasizing the critical need for validated outcome measures, particularly assessments of disease activity and response to treatment. We developed a prototype IgG4-RD Responder Index (IgG4-RD RI) based on the approach used in the development of the Birmingham Vasculitis Activity Score for Wegener's granulomatosis (BVAS/WG). The IgG4-RD RI was refined by members of the International IgG4-RD Symposium Organizing Committee in a paper case exercise. The revised instrument was applied retrospectively to fifteen IgG4-RD patients at our institution. Those scores were compared to physician's global assessment scale for the same visits. This paper describes the philosophy and goals of the IgG4-RD RI, the steps in the development of this instrument to date, and future plans for validation of this instrument as an outcome measure
Correlations among global photometric properties of disk galaxies
Using a two-dimensional galaxy image decomposition technique, we extract
global bulge and disk parameters for a complete sample of early type disk
galaxies in the near infrared K band. We find significant correlation of the
bulge parameter n with the central bulge surface brightness and with
effective radius r_e. Using bivar iate analysis techniques, we find that , and are distributed in a plane with small scatter. We
do not find a strong correlation of n with bulge-to-disk luminosity ratio,
contrary to earlier reports. r_e and the disk scale length r_d are well
correlated for these early type disk galaxies, but with large scatter. We
examine the implications of our results to various bulge formation scenarios in
disk galaxies.Comment: 14 pages, LaTeX including 14 figures. To appear in the Astrophysical
Journa
Serendipitous XMM-Newton discovery of a cluster of galaxies at z=0.28
We report the discovery of a galaxy cluster serendipitously detected as an
extended X-ray source in an offset observation of the group NGC 5044. The
cluster redshift, z=0.281, determined from the optical spectrum of the
brightest cluster galaxy, agrees with that inferred from the X-ray spectrum
using the Fe K alpha complex of the hot ICM (z=0.27 +/- 0.01). Based on the 50
ks XMM observation, we find that within a radius of 383 kpc the cluster has an
unabsorbed X-ray flux, f_X (0.5-2 keV) = 3.34 (+0.08, -0.13) x 10^{-13}
erg/cm^2/s, a bolometric X-ray luminosity, L_X = 2.21 (+0.34, -0.19) x 10^{44}
erg/s, kT = 3.57 +/- 0.12 keV, and metallicity, 0.60 +/- 0.09 solar. The
cluster obeys the scaling relations for L_X and T observed at intermediate
redshift. The mass derived from an isothermal NFW model fit is, M_vir = 3.89
+/- 0.35 x 10^{14} solar masses, with a concentration parameter, c = 6.7 +/-
0.4, consistent with the range of values expected in the concordance
cosmological model for relaxed clusters. The optical properties suggest this
could be a ``fossil cluster''.Comment: 5 pages, 4 colour figures, accepted for publication in Ap
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