6,181 research outputs found
High Pressure optical nanothermometer based on Er3+ photoluminescence
The optical properties of a sparsely investigated material, LaGdO3 doped with Er3+, are explored regarding its suitability as nanothermometer. Besides its excellent capabilities for dielectric applications, when doping with Er3+, this material provides a highly efficient upconversion photoluminescence (PL) for high temperature thermometry at high pressure due to its structural stability. LaGdO3 belongs to the perovskite-type ABO3 compounds with a B-type monoclinic C2/m space group (a = 14.43 Å; b = 3.69 Å; c = 9.00 Å; and ? = 100.70º) at ambient conditions. It undergoes a structural phase transition to a hexagonal ?3#?1 phase at 3GPa yielding a notable PL enhancement, thus enabling it as a potential high-pressure hightemperature nanothermometer.We acknowledge financial support from MAT2015-69508-P (MINECO/FEDER), MAT2015-71070-REDC; PGC2018-101464-B-I00 (MICIN/FEDER), IDIVAL 18/28, the European Research Council FET-OPEN NCLas H2020 Project (EU829161), and BSH Electrodomésticos España, S.A
Osteomielitis vertebral cervical como complicación de cirugía faríngea: a propósito de un caso
Se presenta un caso de un a enferma de 59 años, diabética, afecta de un a
osteomielitis vertebral cervical por Candida Albicans. La vía de infección fué la persistencia
durante varios meses de unos tutores, colocados tras la resección de un a estenosis nasofaríngea ,
que impactaban sobre la cara anterior de la vértebra C3. El desarrollo insidioso y la ausencia
de un cuadro clínico específico fué la causa del retraso diagnóstico.A 5 9 yea r ol d woma n wit h diabete s mellitu s presente d a cervica l
vertebra l osteomyelitis du e t o Candid a Albicans. Th e chroni c implantatio n o f dilatio
n tube s followin g th e resectio n o f a nasopharyngea l stenosis wa s th e mod e o f
infection . Th e insidiou s an d prolonge d onse t an d n o specifica l clinica l pictur e wer e
t h e caus e o f dela y i n th e diagnosi
Low-temperature specific heat of real crystals: Possibility of leading contribution of optical and short-wavelength acoustical vibrations
We point out that the repeatedly reported glass-like properties of
crystalline materials are not necessarily associated with localized (or
quasilocalized) excitations. In real crystals, optical and short-wavelength
acoustical vibrations remain damped due to defects down to zero temperature. If
such a damping is frequency-independent, e.g. due to planar defects or charged
defects, these optical and short-wavelength acoustical vibrations yield a
linear-in- contribution to the low-temperature specific heat of the crystal
lattices. At low enough temperatures such a contribution will prevail over that
of the long-wavelength acoustical vibrations (Debye contribution). The
crossover between the linear and the Debye regime takes place at , where is the concentration of the defects responsible for the
damping. Estimates show that this crossover could be observable.Comment: 5 pages. v4: Error in Appendix corrected, which does not change the
main results of the pape
Electroexcitation of the Roper resonance from CLAS data
The helicity amplitudes of the electroexcitation of the Roper resonance on
proton are extracted at 1.7 < Q2 < 4.2 GeV2 from recent high precision
JLab-CLAS cross sections data and longitudinally polarized beam asymmetry for
pi+ electroproduction on protons. The analysis is made using two approaches,
dispersion relations and unitary isobar model, which give consistent results.
It is found that the transverse helicity amplitude for the gamma* p -->
P11(1440) transition, which is large and negative at Q2=0, becomes large and
positive at Q2 ~ 2 GeV2, and then drops slowly with Q2. Longitudinal helicity
amplitude, that was previously found from CLAS data as large and positive at
Q2=0.4,0.65 GeV2, drops with Q2. These results rule out the presentation of
P11(1440) as a 3qG hybrid state, and provide strong evidence in favor of this
resonance as a first radial excitation of the 3q ground state.Comment: 3 pages, 2 figures, Talk on the Workshop on "The Physics of Excited
Nucleons", Bonn, Germany, October 200
Generalized parton distributions in the deuteron
We introduce generalized quark and gluon distributions in the deuteron, which
can be measured in exclusive processes like deeply virtual Compton scattering
and meson electroproduction. We discuss the basic properties of these
distributions, and point out how they probe the interplay of nucleon and parton
degrees of freedom in the deuteron wave function
From stone masonry to emigrant’s mansions. Changes in vernacular architecture in central Portugal
The research made for this purpose was realized to study the connection between the way of life, the climate, the geology and the vernacular architecture in the parish of Cernache do Bonjardim, municipality of Sertã, central region of Portugal, where various styles of rural houses can be found. The traditional rural home of this territory is constituted by stone walls, mostly made of shales or granite and has two floors: a lower floor with a place for animals or food storage, and an upper floor with the kitchen/living-room and bedrooms. Usually, both floors are joined by outside stairs. Each available space, for instance under these stairs, is used to keep animals like swine or hens, goats or rabbits, and to store food. Usually there is a piece of ground around the house used for the plantation of vegetables and fruit trees. This kind of home is adapted to the people's way of living and the climate, using local materials like stone or wood. In the 19th century there was an emigration wave to Brazil. When the people returned they wanted to show their acquired richness and (sometimes) culture to the neighbours in the village and constructed large houses of mansion-type, which didn't show the strong adaption to the environment anymore, but had other functionalities and a better comfort. As the transportation means improved, the building material was no more limited to the local offer. The emigration from the sixties of the 20th century until today brought new kinds of buildings. Their style was influenced from the country of emigration. There is no more relation to the local style of building. For the construction, modern materials like concrete, tile walls and roof tiles are used. The major conclusions of the research are that the vernacular architecture of the studied region has changed from houses adapted to the climate and the rural way of life, to larger and no more "typical" buildings. The main reasons for this change are the return of emigrants from abroad and its influence, the availability of new materials, the better education and income of the people, the wish to life more comfortably, and the change of the people´s way of life from farming to employment.info:eu-repo/semantics/publishedVersio
The optical identifcation of events with poorly defined locations: The case of the Fermi GBM GRB140801A
We report the early discovery of the optical afterglow of gamma-ray burst
(GRB) 140801A in the 137 deg 3- error-box of the Fermi Gamma-ray
Burst Monitor (GBM). MASTER is the only observatory that automatically react to
all Fermi alerts. GRB 140801A is one of the few GRBs whose optical counterpart
was discovered solely from its GBM localization. The optical afterglow of GRB
140801A was found by MASTER Global Robotic Net 53 sec after receiving the
alert, making it the fastest optical detection of a GRB from a GBM error-box.
Spectroscopy obtained with the 10.4-m Gran Telescopio Canarias and the 6-m BTA
of SAO RAS reveals a redshift of . We performed optical and
near-infrared photometry of GRB 140801A using different telescopes with
apertures ranging from 0.4-m to 10.4-m. GRB 140801A is a typical burst in many
ways. The rest-frame bolometric isotropic energy release and peak energy of the
burst is erg and
keV, respectively, which is consistent with the
Amati relation. The absence of a jet break in the optical light curve provides
a lower limit on the half-opening angle of the jet deg. The
observed is consistent with the limit derived from the
Ghirlanda relation. The joint Fermi GBM and Konus-Wind analysis shows that GRB
140801A could belong to the class of intermediate duration. The rapid detection
of the optical counterpart of GRB 140801A is especially important regarding the
upcoming experiments with large coordinate error-box areas.Comment: in press MNRAS, 201
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