1,134 research outputs found
La creatividad en las actividades motrices
Hace relativamente no mucho tiempo que la noción de creatividad comenzó a cobrar importancia. Muchos han sido los autores que, desde entonces, han tratado de dotar de rigor y operatividad al constructo. Sin embargo, su relación con el ámbito de la motricidad no ha sido estudiada con suficiente dedicación. A continuación se ofrece algunas claves para entenderlo, en un intento por acercar esta capacidad humana al contexto de la actividad física
Uncertainty principle for experimental measurements: Fast versus slow probes
The result of a physical measurement depends on the timescale of the
experimental probe. In solid-state systems, this simple quantum mechanical
principle has far-reaching consequences: the interplay of several degrees of
freedom close to charge, spin or orbital instabilities combined with the
disparity of the time scales associated to their fluctuations can lead to
seemingly contradictory experimental findings. A particularly striking example
is provided by systems of adatoms adsorbed on semiconductor surfaces where
different experiments -- angle-resolved photoemission, scanning tunneling
microscopy and core-level spectroscopy -- suggest different ordering phenomena.
Using most recent first principles many-body techniques, we resolve this puzzle
by invoking the time scales of fluctuations when approaching the different
instabilities. These findings suggest a re-interpretation of ordering phenomena
and their fluctuations in a wide class of solid-state systems ranging from
organic materials to high-temperature superconducting cuprates.Comment: 12 pages, 4 figure
La creativitat en les activitats motrius
No fa gaire, relativament, que la noció de creativitat ha començat a prendre importància. Des d’aleshores han estat molts els autors que han tractat de dotar de rigor i operativitat el constructe. Tanmateix, la seva relació amb l’àmbit de la motricitat no ha estat estudiada amb prou dedicació. A continuació s’ofereixen algunes claus per entendre’l, en un intent d’acostar aquesta capacitat humana al context de l’activitat física
The broad away side of azimuthal correlations: 3 vs 2 final state particles in high energy nuclear collisions
In high energy heavy ion collisions at RHIC there are important aspects of
the medium induced dynamics, that are still not well understood. In particular,
there is a broadening and even a double hump structure of the away-side peak
appearing in azimuthal correlation studies in Au+Au collisions which is absent
in p+p collisions at the same energies. These features are already present but
suppressed in p+p collisions: 2 to 3 parton processes produce such structures
but are suppressed with respect to 2 to 2 processes. We argue that in A+A
collisions the different geometry for the trajectories of 3 as opposed to 2
particles in the final state, together with the medium induced energy loss
effects on the different cross sections, create a scenario that enhances
processes with 3 particles in the final state, which gives on average this
double hump structure.Comment: Prepared for the 5th International Workshop on High-pT Physics at
LHC, ICN-UNAM, 27 Sep.-1 Oct, 201
Three and two-hadron correlations in \sqrt{s_{NN}}=200 GeV proton-proton and nucleus-nucleus collisions
We compare the azimuthal correlations arising from three and two hadron
production in high energy proton-proton and nucleus-nucleus collisions at
\sqrt{s_{NN}}=200 GeV, using the leading order matrix elements for two-to-three
and two-to-two parton-processes in perturbative QCD. We first compute the two
and three hadron production cross sections in mid-rapidity proton-proton
collisions. Then we consider Au + Au collisions including parton energy loss
using the modified fragmentation function approach. By examining the
geometrical paths the hard partons follow through the medium, we show that the
two away-side partons produced in two-to-three processes have in average a
smaller and a greater path length than the average path length of the away-side
parton in two-to-two processes. Therefore there is a large probability that in
the former processes one of the particles escapes while the other gets
absorbed. This effect leads to an enhancement in the azimuthal correlations of
the two-to-three with respect to the two-to-two parton-processes when comparing
to the same processes in proton-proton collisions since in average the particle
with the shortest path length looses less energy with respect to the away side
particle in two-to-two processes. We argue that this phenomenon may be
responsible for the shape of the away-side in azimuthal correlations observed
in mid-rapidity Au + Au collisions at RHIC.Comment: 4 pages, 2 figure
Comparación del sodio plasmático preoperatorio vs posoperatorio según el volumen de irrigación de glicina en cirugía de resección transuretral de próstata de julio 2021 a septiembre 2021, en el HEP
"Los procedimientos urológicos son de los principales procedimientos quirúrgicos realizados a nivel mundial, por lo cual es necesario poder estimar posibles complicaciones posoperatorias de estos procedimientos. La hiperplasia prostática benigna (HPB) es de los principales padecimientos urológicos que requieren manejo quirúrgico de menor invasión, como es la resección transuretral de próstata (RTUP). Una de las complicaciones potenciales de este procedimiento quirúrgico es el síndrome post RTUP causado por el uso de soluciones de irrigación ocasionando una hiponatremia dilucional. Por esta razón, el objetivo de la siguiente tesis es determinar la diferencia del sodio plasmático preoperatorio con el posoperatorio en relación con el volumen de irrigación con glicina 1.5% en el quirófano o UCPA, en pacientes sometidos a cirugía de RTUP en la UMAE HEP CMN “Manuel Ávila Camacho” del IMSS"
Análisis de interfaces y funcionalidades de portales de editoriales universitarias
Esta pasantía de investigación estuvo orientada a apoyar la ejecución del proyecto Sistema
software para la gestión de la investigación, el desarrollo, la innovación, el emprendimiento
y la creación artística y cultural en la Universidad del Magdalena, específicamente en
identificar y analizar los aspectos de diseño, servicios y funcionalidades de portales de
Editoriales universitarias. De acuerdo con los resultados obtenidos de dicho análisis se
construyó una propuesta de diseño para el portal web de la Editorial de la Universidad del
Magdalena
Electronic structure of epitaxial graphene grown on the C-face of SiC and its relation to the structure
International audienceThe interest in graphene stems from its unique band structure that photoemission spectroscopy can directly probe. However, the preparation method can significantly alter graphene's pristine atomic structure and in turn the photoemission spectroscopy spectra. After a short review of the observed band structure for graphene prepared by various methods, we focus on graphene grown on silicon carbide. The semiconducting single crystalline hexagonal SiC provides a substrate of various dopings, where bulk bands do not interfere with that of graphene. Large sheets of high structural quality flat graphene grow on SiC, which allows the exact same material to be used for fundamental studies and as a platform for scalable electronics. Moreover, a new graphene allotrope (multilayer epitaxial graphene) was discovered to grow on the 4H-SiC C-face by the confinement controlled sublimation method. We will focus on the electronic structure of this new graphene allotrope and its connection to its atomic structure
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