233 research outputs found
Synthesis and characterization of tungsten trioxide powders prepared from tungstic acids
WO3 powders were prepared by the thermal decomposition of tungstic acids (WO3 nH2O, n ¼ 1/3, 1, 2). The
tungstic acids were synthesized from WO4
2 aqueous solutions under a variety of conditions of pH, temperature
and W(VI) concentrations. The thermal decomposition of the tungstic acids into WO3 was analysed by TG and
DSC methods. Nano-sized WO3 powders with different morphological characteristics were obtained by thermal
treatment of the tungstic acids at 500 8C in air atmosphere. The morphologies of WO3 powders were
characterised by scanning electron microscopy and infrared absorption spectroscopy. Patterns of infrared spectra
were related with distinct powder morphologies
Vitamin E-analog Trolox prevents endoplasmic reticulum stress in frozen-thawed ovarian tissue of capuchin monkey (Sapajus apella)
Ovarian fragments were exposed to 0.5 M sucrose
and 1 M ethylene glycol (freezing solution; FS) with or
without selenium or Trolox. Histological and ultrastructural
analyses showed that the percentages of normal follicles in
control tissue and in tissue after exposure to FS+50 μM
Trolox were similar. Trolox prevented endoplasmic reticulum
(ER)-related vacuolization, which is commonly observed in
oocytes and stromal tissue after exposure to FS. From the evaluated stress markers, superoxide dismutase 1 (SOD1)
was up-regulated in ovarian tissue exposed to FS+10 ng/ml
selenium. Ovarian fragments were subsequently frozenthawed
in the presence of FS with or without 50 μM Trolox,
followed by in vitro culture (IVC). Antioxidant capacity in
ovarian fragments decreased after freeze-thawing in Troloxfree
FS compared with FS+50 μMTrolox. Although freezing
itself minimized the percentage of viable follicles in each solution, Trolox supplementation resulted in higher rates of
viable follicles (67 %), even after IVC (61 %). Furthermore,
stress markers SOD1 and ERp29 were up-regulated in ovarian
tissue frozen-thawed in Trolox-free medium. Relative mRNA
expression of growth factors markers was evaluated after
freeze-thawing followed by IVC. BMP4, BMP5, CTGF,
GDF9 and KL were down-regulated independently of the
presence of Trolox in FS but down-regulation was less pronounced
in the presence of Trolox. Thus, medium supplementation
with 50 μMTrolox prevents ER stress and, consequently,
protects ovarian tissue from ER-derived cytoplasmic
vacuolization. ERp29 but not ERp60, appears to be a key
marker linking stress caused by freezing-thawing and cell
vacuolization.http://link.springer.com/journal/441hb201
Effect of doped and undoped POMA on the morphology and miscibility of blends with Poly(vinylidene fluoride) (PVDF)
Bayesian joint estimation of non-Gaussianity and the power spectrum
We propose a rigorous, non-perturbative, Bayesian framework which enables one
jointly to test Gaussianity and estimate the power spectrum of CMB
anisotropies. It makes use of the Hilbert space of an harmonic oscillator to
set up an exact likelihood function, dependent on the power spectrum and on a
set of parameters , which are zero for Gaussian processes. The latter
can be expressed as series of cumulants; indeed they perturbatively reduce to
cumulants. However they have the advantage that their variation is essentially
unconstrained. Any truncation(i.e.: finite set of ) therefore still
produces a proper distribution - something which cannot be said of the only
other such tool on offer, the Edgeworth expansion. We apply our method to Very
Small Array (VSA) simulations based on signal Gaussianity, showing that our
algorithm is indeed not biased.Comment: 11pages, 4 figures, submitted to MNRA
Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at TeV
The elliptic, , triangular, , and quadrangular, , azimuthal
anisotropic flow coefficients are measured for unidentified charged particles,
pions and (anti-)protons in Pb-Pb collisions at TeV
with the ALICE detector at the Large Hadron Collider. Results obtained with the
event plane and four-particle cumulant methods are reported for the
pseudo-rapidity range at different collision centralities and as a
function of transverse momentum, , out to GeV/.
The observed non-zero elliptic and triangular flow depends only weakly on
transverse momentum for GeV/. The small dependence
of the difference between elliptic flow results obtained from the event plane
and four-particle cumulant methods suggests a common origin of flow
fluctuations up to GeV/. The magnitude of the (anti-)proton
elliptic and triangular flow is larger than that of pions out to at least
GeV/ indicating that the particle type dependence persists out
to high .Comment: 16 pages, 5 captioned figures, authors from page 11, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186
Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at TeV
The inclusive transverse momentum () distributions of primary
charged particles are measured in the pseudo-rapidity range as a
function of event centrality in Pb-Pb collisions at
TeV with ALICE at the LHC. The data are presented in the range
GeV/ for nine centrality intervals from 70-80% to 0-5%.
The Pb-Pb spectra are presented in terms of the nuclear modification factor
using a pp reference spectrum measured at the same collision
energy. We observe that the suppression of high- particles strongly
depends on event centrality. In central collisions (0-5%) the yield is most
suppressed with at -7 GeV/. Above
GeV/, there is a significant rise in the nuclear modification
factor, which reaches for GeV/. In
peripheral collisions (70-80%), the suppression is weaker with almost independently of . The measured nuclear
modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/284
Measurement of charm production at central rapidity in proton-proton collisions at TeV
The -differential production cross sections of the prompt (B
feed-down subtracted) charmed mesons D, D, and D in the rapidity
range , and for transverse momentum GeV/, were
measured in proton-proton collisions at TeV with the ALICE
detector at the Large Hadron Collider. The analysis exploited the hadronic
decays DK, DK, DD, and their charge conjugates, and was performed on a
nb event sample collected in 2011 with a
minimum-bias trigger. The total charm production cross section at TeV and at 7 TeV was evaluated by extrapolating to the full phase space
the -differential production cross sections at TeV
and our previous measurements at TeV. The results were compared
to existing measurements and to perturbative-QCD calculations. The fraction of
cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/307
Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at = 2.76 TeV
The yield of charged particles associated with high- trigger
particles ( GeV/) is measured with the ALICE detector in
Pb-Pb collisions at = 2.76 TeV relative to proton-proton
collisions at the same energy. The conditional per-trigger yields are extracted
from the narrow jet-like correlation peaks in azimuthal di-hadron correlations.
In the 5% most central collisions, we observe that the yield of associated
charged particles with transverse momenta GeV/ on the
away-side drops to about 60% of that observed in pp collisions, while on the
near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/350
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