1,696 research outputs found
The 43GHz SiO maser in the circumstellar envelope of the AGB star R Cassiopeiae
We present multi-epoch, total intensity, high-resolution images of 43GHz,
v=1, J=1-0 SiO maser emission toward the Mira variable R Cas. In total we have
23 epochs of data for R Cas at approximate monthly intervals over an optical
pulsation phase range from 0.158 to 1.78. These maps show a ring-like
distribution of the maser features in a shell, which is assumed to be centred
on the star at a radius of 1.6 to 2.3 times the stellar radii. It is clear from
these images that the maser emission is significantly extended around the star.
At some epochs a faint outer arc can be seen at 2.2 stellar radii. The
intensity of the emission waxes and wanes during the stellar phase. Some maser
features are seen infalling as well as outflowing. We have made initial
comparisons of our data with models by Gray et. al. (2009).Comment: 12 pages, 14 figure
High Curie temperature Mn 5 Ge 3 thin films produced by non-diffusive reaction
Polycrystalline Mn 5 Ge 3 thin films were produced on SiO 2 using magnetron
sputtering and reactive diffusion (RD) or non-diffusive reaction (NDR). In situ
X-ray diffraction and atomic force microscopy were used to determine the layer
structures, and magnetic force microscopy, superconducting quantum interference
device and ferromagnetic resonance were used to determine their magnetic
properties. RD-mediated layers exhibit similar magnetic properties as MBE-grown
monocrystalline Mn 5 Ge 3 thin films, while NDR-mediated layers show magnetic
properties similar to monocrystalline C-doped Mn 5 Ge 3 C x thin films with
NDR appears as a CMOS-compatible efficient method to
produce good magnetic quality high-curie temperature Mn 5 Ge 3 thin films
Polarization morphology of SiO masers in the circumstellar envelope of the AGB star R Cassiopeiae
Silicon monoxide maser emission has been detected in the circumstellar
envelopes of many evolved stars in various vibrationally-excited rotational
transitions. It is considered a good tracer of the wind dynamics close to the
photosphere of the star. We have investigated the polarization morphology in
the circumstellar envelope of an AGB star, R Cas. We mapped the linear and
circular polarization of SiO masers in the v=1, J=1-0 transition. The linear
polarization is typically a few tens of percent while the circular polarization
is a few percent. The fractional polarization tends to be higher for emission
of lower total intensity. We found that, in some isolated features the
fractional linear polarization appears to exceed 100%. We found the Faraday
rotation is not negligible but is ~15 deg., which could produce small scale
structure in polarized emission whilst total intensity is smoother and partly
resolved out. The polarization angles vary considerably from feature to feature
but there is a tendency to favour the directions parallel or perpendicular to
the radial direction with respect to the star. In some features, the
polarization angle abruptly flips 90 deg. We found that our data are in the
regime where the model of Goldreich et al (1973) can be applied and the
polarization angle flip is caused when the magnetic field is at close to 55
deg. to the line of sight. The polarization angle configuration is consistent
with a radial magnetic field although other configurations are not excluded.Comment: 14 pages, 15 figures. Accepted for publication in MNRA
Experimental Overlay of Glazon over Two Bridge Decks
In accordance with a Personal Service Agreement entered into with the Glazon Industries, Inc., on July 2, 1971, the two subject decks were patched and overlayed with Glazon. On July 27, 1971, work started on RP 106-286-HG3, KY 395 bridge over I 64 in Shelby County. Work consisted of routing old concrete and sandblasting the surface (Figures 1 and 2). State personnel and equipment were used for all cleaning operations. The same procedures were followed to clean HM 99-1324A-MB3 in Powell County near Clay City.
On July 28, 1971, Glazon personnel and equipment arrived at the work site in Shelby County. Glazon representatives judged the cleaning adequate and proceeded with patching the southbound lane (Figure 3). No accurate information is available as to the exact formulation of the Glazon used or proportions in the mix. Glazon Industries declined disclosure of such information since their material was not patented. Before patching, the holes were thoroughly dried. Shrinkage and cracking were noticed in the patches shortly after drying (Figure 4). Later, on other lanes, patch holes were primed with a Glazon liquid before patching (Figures 5 and 6).
After a short drying period, the deck was sprayed with a Glazon mix similar to that for patching but more fluid (Figures 7 and 8). Some problems were encountered due to weak air supply, but were shortly overcome. The sprayed deck looked satisfactory to Glazon personnel who did most of the work in patching and overlaying the deck. The operation was moved to the Clay City bridge and the same procedures were followed in working the northbound lane.
Two wingwalls on the Shelby County bridge were sprayed with a Glazon mix made with white cement.
On August 3, 1971, both bridges were completed though work was interrupted by rain several times. On August 5, 1971, both bridges were reopened to two-lane traffic.
This Division closely observed these operations from the beginning. It was later learned from the Division of Maintenance that the northbound lane of the Shelby County deck, which was badly deteriorating, had been repaired on September 15, 1971
Overlap properties of geometric expanders
The {\em overlap number} of a finite -uniform hypergraph is
defined as the largest constant such that no matter how we map
the vertices of into , there is a point covered by at least a
-fraction of the simplices induced by the images of its hyperedges.
In~\cite{Gro2}, motivated by the search for an analogue of the notion of graph
expansion for higher dimensional simplicial complexes, it was asked whether or
not there exists a sequence of arbitrarily large
-uniform hypergraphs with bounded degree, for which . Using both random methods and explicit constructions, we answer this
question positively by constructing infinite families of -uniform
hypergraphs with bounded degree such that their overlap numbers are bounded
from below by a positive constant . We also show that, for every ,
the best value of the constant that can be achieved by such a
construction is asymptotically equal to the limit of the overlap numbers of the
complete -uniform hypergraphs with vertices, as
. For the proof of the latter statement, we establish the
following geometric partitioning result of independent interest. For any
and any , there exists satisfying the
following condition. For any , for any point and
for any finite Borel measure on with respect to which
every hyperplane has measure , there is a partition into measurable parts of equal measure such that all but
at most an -fraction of the -tuples
have the property that either all simplices with
one vertex in each contain or none of these simplices contain
Autoantibodies Status of Leishmanial Patients in Iraq
A total of 145 leishmaniasis Iraqi patients were collected from suspected cases and 30 healthy control. Based on skin smear examination and serum samples analysis, the patients were distributed into two clinical groups: 30 cutaneous leishmaniasis and 30 visceral leishmaniasis patients. The study was conducted for the detection of 17 types of antinuclear autoantibodies (ANA) in studied groups, 10 types including (anti-ds-DNA, anti-Nucleosome, anti-SmD1, anti-PCNA, anti-SS-A/Ro60kD, anti-SS-A/Ro52kD, anti-SS-B/La, anti-CENP-B, anti-Mi-2 and anti-Ku antibodies), showed significant differences (P?0.05), (P?0.01) in the two groups, while 7 types which were non-significant included (anti-histones, anti-ribosomal P0, anti-Scl70, anti-U1-snRNP, anti-AMA M2, anti-Jo1 and anti-PM-Scl antibodies). With respect to the Anti-cardiolipin IgG antibodies (aCL), it showed a significant increased level in the serum of VL patients (P?0.01) as compared with control group (8.123 vs. 1.959), also as compared with CL patients (8.123 vs. 2.402). As for CL patients, also there was a significant difference (P?0.01) (2.402 vs. 8.123) when compared with VL patients, but no significant variations (2.402 vs. 1.959) were observed in compare with control group. We conclude that Leishmaniasis in iraqi patients may be considered as a cause autoimmune diseases as in case of inflammatory myopathies (IM), and the pathgenesis of human myositis, especially in VL which contributes in the immunological alterations associated with muscle damage. Keywords: Leishmania species, autoantibodies, antinuclear antibodies, anticardiolipin
Advertising spending, firm performance, and the moderating impact of CSR
This article investigates the potential of corporate social responsibility (CSR) to influence the link between advertising spending and firm performance. Drawing upon the literature of CSR, we hypothesize that CSR positively moderates the relationship between advertising spending and firm performance. We focus on two types of firm performance: sales and firm value. Using two samples from both the hotel and restaurant industries, we found that firms with higher levels of CSR enjoy higher returns on advertising spending than firms with lower levels of CSR. We discuss the theoretical and managerial implications of these findings and provide direction for future research
Agricultural knowledge from academy to farming communities: The role of higher education in enhancing food security in Syria
The dynamics of the Syrian conflict
present a complex set of challenges that
led to considering more than 10.5 million
people food insecure and in need of urgent
agricultural and livelihood assistance.
This article investigates the role of higher
education (HE) in food security. It considers
how universities, graduates, and appropriate
curriculum and research engagement can
address challenges and provide innovative
solutions in Syria
Patient-Led Research Collaborative: embedding patients in the Long COVID narrative
A large subset of patients with coronavirus disease 2019 (COVID-19) are experiencing symptoms well beyond the claimed 2-week recovery period for mild cases. These long-term sequelae have come to be known as Long COVID. Originating out of a dedicated online support group, a team of patients formed the Patient-Led Research Collaborative and conducted the first research on Long COVID experience and symptoms. This article discusses the history and value of patient-centric and patient-led research; the formation of Patient-Led Research Collaborative as well as key findings to date; and calls for the following: the acknowledgement of Long COVID as an illness, an accurate estimate of the prevalence of Long COVID, publicly available basic symptom management, care, and research to not be limited to those with positive polymerase chain reaction and antibody tests, and aggressive research and investigation into the pathophysiology of symptoms
First Passage Distributions in a Collective Model of Anomalous Diffusion with Tunable Exponent
We consider a model system in which anomalous diffusion is generated by
superposition of underlying linear modes with a broad range of relaxation
times. In the language of Gaussian polymers, our model corresponds to Rouse
(Fourier) modes whose friction coefficients scale as wavenumber to the power
. A single (tagged) monomer then executes subdiffusion over a broad range
of time scales, and its mean square displacement increases as with
. To demonstrate non-trivial aspects of the model, we numerically
study the absorption of the tagged particle in one dimension near an absorbing
boundary or in the interval between two such boundaries. We obtain absorption
probability densities as a function of time, as well as the position-dependent
distribution for unabsorbed particles, at several values of . Each of
these properties has features characterized by exponents that depend on
. Characteristic distributions found for different values of
have similar qualitative features, but are not simply related quantitatively.
Comparison of the motion of translocation coordinate of a polymer moving
through a pore in a membrane with the diffusing tagged monomer with identical
also reveals quantitative differences.Comment: LaTeX, 10 pages, 8 eps figure
- …