Search results for " física"
showing 10 items of 920 documents
Imagen de la Física universitaria: el punto de vista del profesor y del alumno
2013
Este trabajo pretende indagar en algunos factores cognitivos y actitudinales que inciden en la elección y adaptación de los alumnos que ingresan en carreras científicas. Para ello se parte de una revisión teórica sobre las actitudes hacia la ciencia y la orientación vocacional. Posteriormente se describen los resultados de sendas encuestas realizadas a alumnos de Ingeniería Química y de Óptica, así como a algunos profesores, una de ellas diferida en un periodo de cinco años para alumnos de esta última titulación y la otra aplicada tras la visualización de algunas experiencias de laboratorio. Se discuten los resultados de los distintos item, tanto para cada muestra como comparativamente, y s…
Combination of Searches for Invisible Higgs Boson Decays with the ATLAS Experiment
2019
Dark matter particles, if sufficiently light, may be produced in decays of the Higgs boson. This Letter presents a statistical combination of searches for H → invisible decays where H is produced according to the standard model via vector boson fusion, Z(ℓℓ)H, and W/Z(had)H, all performed with the ATLAS detector using 36.1 fb⁻¹ of pp collisions at a center-of-mass energy of √s = 13 TeV at the LHC. In combination with the results at √s = 7 and 8 TeV, an exclusion limit on the H → invisible branching ratio of 0.26(0.17-0.05+0.07) at 95% confidence level is observed (expected).
Comparison of distance covered in paddle in the serve team according to performance level
2013
Although paddle is the second most practiced sport in Spain, the scientific knowledge about the players' work-load is still very low. The serve is a critical situation because the team has the opportunity to start the point attacking by approaching the net straight after the serve. However, the distance covered by the serve team still has not been studied in padel. OBJECTIVE: This study aimed to analyse the distance covered by the serve team according performance level. It was hypothesized that the server would cover more distance than his partner due to the approach to the net after the serve. Moreover, it also was hypothesized that the difference between serve and partner would be greater…
Resolution of the ATLAS muon spectrometer monitored drift tubes in LHC Run 2
2019
The momentum measurement capability of the ATLAS muon spectrometer relies fundamentally on the intrinsic single-hit spatial resolution of the monitored drift tube precision tracking chambers. Optimal resolution is achieved with a dedicated calibration program that addresses the specific operating conditions of the 354 000 high-pressure drift tubes in the spectrometer. The calibrations consist of a set of timing offsets and drift time to drift distance transfer relations, and result in chamber resolution functions. This paper describes novel algorithms to obtain precision calibrations from data collected by ATLAS in LHC Run 2 and from a gas monitoring chamber, deployed in a dedicated gas fac…
Electron and photon energy calibration with the ATLAS detector using 2015-2016 LHC proton-proton collision data
2019
Artículo realizado por muchos autores. Solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración y los autores que firman como pertenecientes a la UAM
Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory
2013
We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack of significant clustering in the arrival directions of the highest energy events detected at the Pierre Auger Observatory. The density of uniformly distributed sources of equal intrinsic intensity was found to be larger than similar to (0.06 – 5) x 10(-4) Mpc(-3) at 95% CL, depending on the magnitude of the magnetic defections. Similar bounds, in the range (0.2 – 7) x 10(-4) Mpc(-3), were obtained for sources following the local matter distribution.
Interpretation of the depths of maximum of extensive air showers measured by the Pierre Auger Observatory
2013
To interpret the mean depth of cosmic ray air shower maximum and its dispersion, we parametrize those two observables as functions of the first two moments of the ln A distribution. We examine the goodness of this simple method through simulations of test mass distributions. The application of the parameterization to Pierre Auger Observatory data allows one to study the energy dependence of the mean ln A and of its variance under the assumption of selected hadronic interaction models. We discuss possible implications of these dependences in term of interaction models and astrophysical cosmic ray sources.
Searches for anisotropies in the arrival directions of the highest energy cosmic rays detected by the Pierre Auger Observatory
2015
We analyze the distribution of arrival directions of ultra-high energy cosmic rays recorded at the Pierre Auger Observatory in 10 years of operation. The data set, about three times larger than that used in earlier studies, includes arrival directions with zenith angles up to $80^\circ$, thus covering from $-90^\circ$ to $+45^\circ$ in declination. After updating the fraction of events correlating with the active galactic nuclei (AGNs) in the V��ron-Cetty and V��ron catalog, we subject the arrival directions of the data with energies in excess of 40 EeV to different tests for anisotropy. We search for localized excess fluxes and for self-clustering of event directions at angular scales up t…
Metodología para la estimación del gasto energético en lesionados medulares mediante el empleo de acelerómetros
2012
Los objetivos de la tesis fueron diseñar modelos lineales generales y redes neuronales artificiales para estimar el gasto energético de personas con paraplejia. Para ello se realizó un estuio descriptivo transversal en el que 20 personas con paraplejia realizaron una rutina de 10 actividades. Cada actividad tuvo una duración de 10 minutos y durante la realización de la misma se adquirieron datos de frecuencia cardiaca, consumo de oxínego y aceleraciones. Concretamente se colocaron 4 acelerómetros triaxiales, uno en cada muñeca, otro en el pecho y el último en la cintura. Una vez procesadas las señales y extraídas las características de interés se diseñaron los modelos matemáticos de estimac…
Uso de teléfonos inteligentes para la promoción y medición de la actividad física en personas con lesión medular
2021
Los teléfonos inteligentes o smartphones son una herramienta con un gran potencial para realizar intervenciones centradas en la promoción de la actividad física. Poblaciones como las personas con paraplejia pueden beneficiarse de estos dispositivos, ya que mantener niveles adecuados de actividad física es de gran importancia para su salud. Sin embargo, actualmente son todavía pocos los estudios que se centran en el uso de nuevas tecnologías para promocionar la actividad física en esta población. Por ello, los objetivos de este trabajo de investigación son (i) validar el uso de los smartphones para la medición del gasto energético en personas con paraplejia y (ii) evaluar los efectos de una …