13,214 research outputs found
Supersymmetric Lifshitz-like backgrounds from N=4 SYM with heavy quark density
We examine a class of gravity backgrounds obtained by considering the
backreaction of a spatially uniform density of mutually BPS Wilson lines or
heavy quarks in N=4 SUSY Yang-Mills theory. The configurations preserve eight
supercharges and an SO(5) subgroup of the SO(6) R-symmetry. They are obtained
by considering the 1/4-BPS geometries associated to smeared string/D3-brane
(F1-D3) intersections. We argue that for the (partially) localized
intersection, the geometry exhibits a flow from AdS_5 x S^5 in the UV to a
novel IR scaling solution displaying anisotropic Lifshitz-like scaling with
dynamical critical exponent z=7, hyperscaling violation and a logarithmic
running dilaton. We also obtain a two-parameter family of smeared 1/4-BPS
solutions on the Coulomb branch of N=4 SYM exhibiting Lifshitz scaling and
hyperscaling violation. For a certain parametric range these yield IR
geometries which are conformal to AdS_2 x R^3, and which have been argued to be
relevant for fermionic physics.Comment: 24 pages, 2 figures, references added, version published in JHEP,
Feb. 201
Water system virus detection
The performance of a waste water reclamation system is monitored by introducing a non-pathogenic marker virus, bacteriophage F2, into the waste-water prior to treatment and, thereafter, testing the reclaimed water for the presence of the marker virus. A test sample is first concentrated by absorbing any marker virus onto a cellulose acetate filter in the presence of a trivalent cation at low pH and then flushing the filter with a limited quantity of a glycine buffer solution to desorb any marker virus present on the filter. Photo-optical detection of indirect passive immune agglutination by polystyrene beads indicates the performance of the water reclamation system in removing the marker virus. A closed system provides for concentrating any marker virus, initiating and monitoring the passive immune agglutination reaction, and then flushing the system to prepare for another sample
Water system virus detection
A monitoring system developed to test the capability of a water recovery system to reject the passage of viruses into the recovered water is described. A nonpathogenic marker virus, bacteriophage F2, is fed into the process stream before the recovery unit and the reclaimed water is assayed for its presence. Detection of the marker virus consists of two major components, concentration and isolation of the marker virus, and detection of the marker virus. The concentration system involves adsorption of virus to cellulose acetate filters in the presence of trivalent cations and low pH with subsequent desorption of the virus using volumes of high pH buffer. The detection of the virus is performed by a passive immune agglutination test utilizing specially prepared polystyrene particles. An engineering preliminary design was performed as a parallel effort to the laboratory development of the marker virus test system. Engineering schematics and drawings of a fully functional laboratory prototype capable of zero-G operation are presented. The instrument consists of reagent pump/metering system, reagent storage containers, a filter concentrator, an incubation/detector system, and an electronic readout and control system
The nebular spectra of SN 2012aw and constraints on stellar nucleosynthesis from oxygen emission lines
We present nebular phase optical and near-infrared spectroscopy of the Type
IIP supernova SN 2012aw combined with NLTE radiative transfer calculations
applied to ejecta from stellar evolution/explosion models. Our spectral
synthesis models generally show good agreement with the ejecta from a MZAMS =
15 Msun progenitor star. The emission lines of oxygen, sodium, and magnesium
are all consistent with the nucleosynthesis in a progenitor in the 14 - 18 Msun
range. We also demonstrate how the evolution of the oxygen cooling lines of [O
I] 5577 A, [O I] 6300 A, and [O I] 6364 A can be used to constrain the mass of
oxygen in the non-molecularly cooled ashes to < 1 Msun, independent of the
mixing in the ejecta. This constraint implies that any progenitor model of
initial mass greater than 20 Msun would be difficult to reconcile with the
observed line strengths. A stellar progenitor of around MZAMS = 15 Msun can
consistently explain the directly measured luminosity of the progenitor star,
the observed nebular spectra, and the inferred pre-supernova mass-loss rate. We
conclude that there is still no convincing example of a Type IIP explosion
showing the nucleosynthesis expected from a MZAMS > 20 Msun progenitor.Comment: Accepted for publication in MNRA
Experimental results of crystal-assisted slow extraction at the SPS
The possibility of extracting highly energetic particles from the Super
Proton Synchrotron (SPS) by means of silicon bent crystals has been explored
since the 1990's. The channelling effect of a bent crystal can be used to
strongly deflect primary protons and eject them from the synchrotron. Many
studies and experiments have been carried out to investigate crystal
channelling effects. The extraction of 120 and 270 GeV proton beams has already
been demonstrated in the SPS with dedicated experiments located in the ring.
Presently in the SPS, the UA9 experiment is performing studies to evaluate the
possibility to use bent silicon crystals to steer particle beams in high energy
accelerators. Recent studies on the feasibility of extraction from the SPS have
been made using the UA9 infrastructure with a longer-term view of using
crystals to help mitigate slow extraction induced activation of the SPS. In
this paper, the possibility to eject particles into the extraction channel in
LSS2 using the bent crystals already installed in the SPS is presented. Details
of the concept, simulations and measurements carried out with beam are
presented, before the outlook for the future is discussed.Comment: 4 pages, 7 figures, submitted to to International Particle
Accelerator Conference (IPAC) 2017 in Copenhagen, Denmar
Prototipo funcional de un servicio e-Health para monitorear, transmitir y almacenar el estado de la presión arterial de pacientes crónicos-hipertensos
Auxiliar de InvestigaciónEn la siguiente proyecto de grado se desarrolla un prototipo funcional para el monitoreo de pacientes crónicos hipertensos con visualización remota. inicialmente mediante un proceso de ingeniería inversa, se realiza la adaptación de un tensiometro comercial para obtener los datos tomados por este, los datos son enviados vía bluetooth a una tarjeta de desarrollo para ser procesados y por medio de una shield M95 de quectel, se realiza el envío de mensajes de alerta y el envío de estos datos a una base de datos creada en ThingSpeak, para luego en el front de una pagina web desarrollada en el entorno de Azure se puedan visualizar los datos de cada paciente.INTRODUCCIÓN
1. GENERALIDADES
2. DESCRIPCION DE COMPONENTES
3. IMPLEMENTACION
4. PRUEBAS DE FUNCIONAMIENTO
5. VALIDACIÓN DEL DISPOSITIVO
6. DESCRIPCIÓN ECONOMICA DEL PROYECTO
7. CONCLUCIONES
8. TRABAJOS FUTUROS
BIBLIOGRAFÍA
ANEXOSPregradoIngeniero Electrónic
Infrared spectroscopy of solid CO-CO2 mixtures and layers
The spectra of pure, mixed and layered CO and CO2 ices have been studied
systematically under laboratory conditions using infrared spectroscopy. This
work provides improved resolution spectra (0.5 cm-1) of the CO2 bending and
asymmetric stretching mode, as well as the CO stretching mode, extending the
existing Leiden database of laboratory spectra to match the spectral resolution
reached by modern telescopes and to support the interpretation of the most
recent data from Spitzer. It is shown that mixed and layered CO and CO2 ices
exhibit very different spectral characteristics, which depend critically on
thermal annealing and can be used to distinguish between mixed, layered and
thermally annealed CO-CO2 ices. CO only affects the CO2 bending mode spectra in
mixed ices below 50K under the current experimental conditions, where it
exhibits a single asymmetric band profile in intimate mixtures. In all other
ice morphologies the CO2 bending mode shows a double peaked profile, similar to
that observed for pure solid CO2. Conversely, CO2 induces a blue-shift in the
peak-position of the CO stretching vibration, to a maximum of 2142 cm-1 in
mixed ices, and 2140-2146 cm-1 in layered ices. As such, the CO2 bending mode
puts clear constraints on the ice morphology below 50K, whereas beyond this
temperature the CO2 stretching vibration can distinguish between initially
mixed and layered ices. This is illustrated for the low-mass YSO HH46, where
the laboratory spectra are used to analyse the observed CO and CO2 band
profiles and try to constrain the formation scenarios of CO2.Comment: Accepted in A&
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