143 research outputs found
Influence of the sintering temperature on ferroelectric properties of potassium-sodium niobate piezoelectric ceramics
The effect of sintering condition on structure, microstructure, and ferroelectric properties of (K0.44Na0.52Li0.04) (Nb0.86Ta0.10Sb0.04)- O3 (KNL-NTS) has been investigated. Ceramic powders have been synthesized by the solid-state reaction method and sintered at different temperatures (1115°C, 1125°C, and 1140°C). Then, samples were characterized by thermogravimetric analysis, X-ray diffraction, scanning electron microscopy, and impedance spectroscopy. Through XRD results, the perovskite structure and small peaks corresponding to a secondary phase were detected. Ceramics processed at the highest temperatures showed higher densities and good piezoelectric properties (d33, Kp, and Kt), particularly specimens sintered at 1125°C presented the highest piezoelectric performance.Fil: Cortés, J. A.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Camargo, Javier Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Rachia, M. F.. Universidade Estadual Paulista Julio de Mesquita Filho; BrasilFil: Rubio Marcos, Fernando. Instituto de Cerámica y Vidrio de Madrid; España. Universidad Nebrija; EspañaFil: Ramajo, Leandro Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Castro, Miriam Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Ramírez, M. A.. Universidade Estadual Paulista Julio de Mesquita Filho; Brasi
Traffic monitoring for assuring quality of advanced services in future internet
The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-21560-5_16Services based on packet switched networks are becoming dominant in telecommunication business and both operators and service providers must evolve in order to guarantee the required quality. Increasing bandwidth is no longer a viable solution because of the business erosion for network operators which cannot expect revenues due to the large investments required to satisfy new applications demand of bandwidth. This paper presents devices and a specific architecture of services monitoring platform that allows network operators and service providers to analyze the perceived quality of service and check their service level agreements. Thus, a cost-effective service management, based on direct IP traffic measuring, can be supported on integrated monitoring systems to provide network-centric mechanisms for differentiated quality of service, security and other advanced services.This work has been partially developed in the framework of the Celtic and EUREKA initiative IPNQSIS (IP Network Monitoring for Quality of Service Intelligent Support)
Localized leishmaniasis of the oral mucosa. A report of three cases
El término leishmaniasis comprende un grupo de enfermedades causadas por diferentes especies de un protozoo llamado Leishmania. La leishmaniasis se produce en todo el mundo, considerándose endémica en 88 países. Existen tres formas clínicas principales de leishmaniasis: leishmaniasis visceral, leishmaniasis cutánea y leishmaniasis mucocutánea. La afectación de la mucosa, de manera exclusiva, por la Leishmania es muy rara. Presentamos una serie de tres casos de leishmaniasis mucosa localizados en la cavidad oral. El hecho de que todos los casos se produjeran en España, área endémica de L infantum, nos hace presuponer que éste fue el agente causal. La única manifestación de enfermedad de leishmaniasis en los casos descritos, fue la aparición de una lesión oral. Se administró tratamiento con antimoniato de meglumina en dos de ellos, respondiendo favorablemente. Uno de los pacientes abandonó el hospital tras el diagnóstico sin recibir tratamiento y se desconoce la evolución. Realizamos también una revisión de la literatura
First experiment: Fragmentation of ions relevant for space and therapy
Nuclear fragmentation processes are relevant in different fields of basic research and applied physics and are of particular interest for tumor therapy and for space radiation protection applications. The FIRST (Fragmentation of Ions Relevant for Space and Therapy) experiment at SIS accelerator of GSI laboratory in Darmstadt, has been designed for the measurement of different ions fragmentation cross sections at different energies between 100 and 1000 MeV/nucleon. The experiment is performed by an international collaboration made of institutions from Germany, France, Italy and Spain. The experimental apparatus is partly based on an already existing setup made of the ALADIN magnet, the MUSIC IV TPC, the LAND2 neutron detector and the TOFWALL scintillator TOF system, integrated with newly designed detectors in the interaction Region (IR) around the carbon removable target: a scintillator Start Counter, a Beam Monitor drift chamber, a silicon Vertex Detector and a Proton Tagger for detection of light fragments emitted at large angles (KENTROS). The scientific program of the FIRST experiment started on summer 2011 with the study of the 400 MeV/nucleon 12C beam fragmentation on thin (8mm) carbon target
Radia2: A New Tool for Radiotherapy Verification
Radiotherapy is nowadays a proven technique in cancer treatments. Within the evolution of radiotherapy treatments towards more complex techniques, the need of new dosimetric methods for treatment verifications has appeared. In order to reach an improved dosimetric method, a collaboration was started to transfer knowledge from nuclear reaction instrumentation to medical applications, involving several departments from the University of Seville, Centro Nacional de Aceleradores (CNA), the Hospital Universitario Virgen Macarena and the company Inabensa. The first prototype, patent pending [2], gave very promising results. Currently, a critical review is being carried out to create an improved system
Transmittance and optical constants of ca films in the 4-1000 eV spectral range
8 págs.; 8 figs.; OCIS codes: (260.7200) Ultraviolet, extreme; (120.4530) Optical constants; (350.2450) Filters, absorption; (230.4170) Multilayers; (310.6860) Thin films, optical properties.© 2015 Optical Society of America. The low expected absorption of Ca in the extreme ultraviolet (EUV) makes it an attractive material for multilayers and filters because most materials in nature strongly absorb the EUV. Few optical constant data had been reported for Ca. In this research, Ca films of various thicknesses were deposited on gridsupported C films and their transmittance measured in situ from the visible to the soft x-rays. The measurement range contains M2,3 and L2,3 absorption edges. Transmittance measurements were used to obtain the Ca extinction coefficient k. A minimum k of 0.017 was obtained at ∼23 eV, which makes Ca a promising low-absorption material for EUV coatings. A second spectral range of interest for its low absorption is below the Ca L3 edge at ∼343 eV. Measured k data and extrapolations were used to calculate the refractive index n using Kramers.Kronig relations. This is the first self-consistent data set on Ca covering a wide spectral range including the EUV.We acknowledge support by the European
Community—Research Infrastructure Action under
the FP6 “Structuring the European Research Area”
Programme (through the Integrated Infrastructure
Initiative “Integrating Activity on Synchrotron and
Free Electron Laser Science”) through proposal
number Ref. 2007655. This work was also supported
by the National Programme for Space Research,
Subdirección General de Proyectos de Investigación,
Ministerio de Ciencia y Tecnología, project numbers
AYA2010-22032 and AYA2013-42590-P. L. Rodrí-
guez-de Marcos and S. García-Cortés are thankful
to Consejo Superior de Investigaciones Científicas
(CSIC) for funding under the Programa JAE,
partially supported by the European Social Fund.
M. Vidal-Dasilva acknowledges financial support
from an FPI fellowship number BES-2006-14047Peer Reviewe
Human-carnivore relations: conflicts, tolerance and coexistence in the American West
Carnivore and humans live in proximity due to carnivore recovery efforts and ongoing human encroachment into carnivore habitats globally. The American West is a region that uniquely exemplifies these human-carnivore dynamics, however, it is unclear how the research community here integrates social and ecological factors to examine human-carnivore relations. Therefore, strategies promoting human-carnivore coexistence are urgently needed. We conducted a systematic review on human-carnivore relations in the American West covering studies between 2000 and 2018. We first characterized human-carnivore relations across states of the American West. Second, we analyzed similarities and dissimilarities across states in terms of coexistence, tolerance, number of ecosystem services and conflicts mentioned in literature. Third, we used Bayesian modeling to quantify the effect of social and ecological factors influencing the scientific interest on coexistence, tolerance, ecosystem services and conflicts. Results revealed some underlying biases in humancarnivore relations research. Colorado and Montana were the states where the highest proportion of studies were conducted with bears and wolves the most studied species. Non-lethal management was the most common strategy to mitigate conflicts. Overall, conflicts with carnivores were much more frequently mentioned than benefits. We found similarities among Arizona, California, Utah, and New Mexico according to how coexistence, tolerance, services and conflicts are addressed in literature. We identified percentage of federal/private land, carnivore family, social actors, and management actions, as factors explaining how coexistence, tolerance, conflicts and services are addressed in literature. We provide a roadmap to foster tolerance towards carnivores and successful coexistence strategies in the American West based on four main domains, (1)the dual role of carnivores as providers of both beneficial and detrimental contributions to people, (2)social-ecological factors underpinning the provision of beneficial and detrimental contributions, (3)the inclusion of diverse actors, and (4) cross-state collaborative management
Study of the scattering of halo nuclei around the Coulomb barrier
During the past ten years the present collaboration has carried out several experiments related with the study of radioactive nuclei. One of the topics in which we have centered our research, is the scattering of halo nuclei at energies around the Coulomb barrier. As part of this study, we present in this work a review of the results obtained from the scattering of 6He, 11Be and 11Li. The presence of a "halo" in these exotic nuclei is found to have a striking effect on the dynamics of these reactions, making their study an interesting experimental problem and a challenge for existing reaction theories.Ministerio de Ciencia y Tecnología FPA2005-04460, FPA2005-02379, FPA-2000-1592-C03-02, FPA2003-05958, FPA2002- 04181-C04-02/03, FPA2006-13807-c02-0, FPA2009- 07653Programa Español Consolider-Ingenio 2010 CSD2007-0004
Scattering of 11 Be around the Coulomb barrier
Preliminary results on the 11Be+120Sn quasielastic scattering as well as the 11Be → 10Be +
n breakup channel are presented in this work. The angular distributions of these channels were
measured at REX-ISOLDE-CERN. The accuracy and angular range of the presented results provide
stronger constrains to the theoretical interpretation than existing published results. We compare
these new data with coupled-channel (CC) and continuum-discretized coupled-channel (CDCC)
calculations. The role played by transfer and breakup channels in the elastic scattering is discussed.CICYT FPA2007- 62170MEC FINURA (FPA2007-63074) CPAN (CSD 2007-00042)DGICYT FPA2006-13807-c02-01 CSD-2007-0004
The CARMENES search for exoplanets around M dwarfs -- A deep learning approach to determine fundamental parameters of target stars
Existing and upcoming instrumentation is collecting large amounts of
astrophysical data, which require efficient and fast analysis techniques. We
present a deep neural network architecture to analyze high-resolution stellar
spectra and predict stellar parameters such as effective temperature, surface
gravity, metallicity, and rotational velocity. With this study, we firstly
demonstrate the capability of deep neural networks to precisely recover stellar
parameters from a synthetic training set. Secondly, we analyze the application
of this method to observed spectra and the impact of the synthetic gap (i.e.,
the difference between observed and synthetic spectra) on the estimation of
stellar parameters, their errors, and their precision. Our convolutional
network is trained on synthetic PHOENIX-ACES spectra in different optical and
near-infrared wavelength regions. For each of the four stellar parameters,
, , [M/H], and , we constructed a neural
network model to estimate each parameter independently. We then applied this
method to 50 M dwarfs with high-resolution spectra taken with CARMENES (Calar
Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and
optical Echelle Spectrographs), which operates in the visible (520-960 nm) and
near-infrared wavelength range (960-1710 nm) simultaneously. Our results are
compared with literature values for these stars. They show mostly good
agreement within the errors, but also exhibit large deviations in some cases,
especially for [M/H], pointing out the importance of a better understanding of
the synthetic gap
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