130 research outputs found
Una historia contada con sombras
En el presente texto se analiza el relato cinematográfico de suspenso, sus directices, particularidades y, sobre todo, el impacto generado en el espactador, así como lo que deriva de la comunicación entre relato y lector/espectador. Se utilizan como ejemplo dos cintas: Psicosis (1960), Dir. Alfred Hitchcock, y Los otros (2001), Dir. Alejandro Amenábar
Fast quantum gates based on Landau-Zener-St\"uckelberg-Majorana transitions
Fast quantum gates are of paramount importance for enabling efficient and
error-resilient quantum computations. In the present work we analyze
Landau-Zener-St\"uckelberg-Majorana (LSZM) strong driving protocols, tailored
to implement fast gates with particular emphasis on small gap qubits. We derive
analytical equations to determine the specific set of driving parameters for
the implementation of single qubit and two qubit gates employing single period
sinusoidal pulses. Our approach circumvents the need to scan experimentally a
wide range of parameters and instead it allows to focus in fine-tuning the
device near the analytically predicted values. We analyze the dependence of
relaxation and decoherence on the amplitude and frequency of the pulses,
obtaining the optimal regime of driving parameters to mitigate the effects of
the environment. Our results focus on the study of the single qubit
, and identity gates. Also, we propose
the as the simplest two-qubit gate attainable through a
robust LZSM driving protocol
Comparación del rendimiento de campo de la maquinaria y las especificaciones del fabricante en las actividades de movimiento de tierras de la construcción de una poza en la Mina Summa Gold Corporation – Huamachuco, 2021
La presente investigación busca obtener los rendimientos de la maquinaria del área de proyectos, tales como excavadora (Volvo 380DL y Caterpillar 336DL), un rodillo (BOMAG BW213DH-5), una motoniveladora (Caterpillar 12M), en las actividades de movimiento de tierras de la construcción de una poza de 5000m3 de la mina SUMMA GOLD CORPORATION, y realizar una comparación con los rendimientos indicados por el fabricante (rendimientos teóricos). Los rendimientos reales obtenidos son tomados en campo mediante la observación directa y los resúmenes diarios de control de maquinaria que realiza la unidad minera. Además, se realizó la identificación de los factores adversos propios de un proyecto minero que afectan los rendimientos de la maquinaria.
Posteriormente se realizó una evaluación entre los rendimientos indicados por el fabricante y los rendimientos de campo
Parton picture for the strongly coupled SYM plasma
Deep inelastic scattering off the strongly coupled N=4 supersymmetric
Yang-Mills plasma at finite temperature can be computed within the AdS/CFT
correspondence, with results which are suggestive of a parton picture for the
plasma. Via successive branchings, essentially all partons cascade down to very
small values of the longitudinal momentum fraction x and to transverse momenta
smaller than the saturation momentum Q_s\sim T/x. This scale Q_s controls the
plasma interactions with a hard probe, in particular, the jet energy loss and
its transverse momentum broadening.Comment: 4 pages, Talk given at Quark Matter 2008: 20th International
Conference on Ultra-Relativistic Nucleus Nucleus Collisions (QM 2008),
Jaipur, India, 4-10 Feb 200
Deep inelastic and dipole scattering on finite length hot SYM matter
Deep inelastic scattering of -currents and the scattering of a
small dipole on finite length hot SYM matter are discussed. In
each case we find the scale when scattering becomes strong is determined by a
saturation momentum where is the length of the matter.
For -currents we analyze the operator product expansion. For
infinite length matter the series generated by the OPE is not Borel summable
but we are able to determine the exponential part of the tunneling amplitude
determining when from the position of the
singularity closest to the origin on the real axis of the Borel plane. In
finite length matter the OPE series is not convergent but it is Borel summable.
When a small dipole, and the string connecting the ends of the dipole, pass
through hot matter there is an induced motion of the string in the
dimension. When , with the the rapidity of the string,
is large enough the string would normally break into several parts after
leaving the medium, however, this cannot happen in the classical approximation
in which we work.Comment: 26 page
Desarrollo de un plan de negocio - App de servicio de limpieza
El presente trabajo de investigación de desarrollo de plan de negocio es sobre la creación de una app de servicio de limpieza para jefes de hogar de entre 26 a 65 años, del NSE A y B, que residen en Lima Metropolitana e interesados en servicios de limpieza o mantenimiento y, que este servicio sea seguro y flexible. Por ello, la aplicación tiene como objetivo facilitar la búsqueda de personal de limpieza para los hogares de Lima, para personas que no tienen tiempo suficiente para realizar las tareas del hogar y personas que por su edad no se sienten capacitadas para realizar dicha actividad. Asimismo, para lograr este propósito se ha empleado una metodología de validación de datos a través de experimentos con anuncios falsos sobre el servicio de la app y entrevistas con expertos
On the Beaming of Gluonic Fields at Strong Coupling
We examine the conditions for beaming of the gluonic field sourced by a heavy
quark in strongly-coupled conformal field theories, using the AdS/CFT
correspondence. Previous works have found that, contrary to naive expectations,
it is possible to set up collimated beams of gluonic radiation despite the
strong coupling. We show that, on the gravity side of the correspondence, this
follows directly (for arbitrary quark motion, and independently of any
approximations) from the fact that the string dual to the quark remains
unexpectedly close to the AdS boundary whenever the quark moves
ultra-relativistically. We also work out the validity conditions for a related
approximation scheme that proposed to explain the beaming effect though the
formation of shock waves in the bulk fields emitted by the string. We find that
these conditions are fulfilled in the case of ultra-relativistic uniform
circular motion that motivated the proposal, but unfortunately do not hold for
much more general quark trajectories.Comment: 1+33 pages, 2 figure
Isoscalar response of Ni-68 to alpha-particle and deuteron probes
Isoscalar giant resonances have been measured in the unstable Ni-68 nucleus using inelastic alpha and deuteron scattering at 50A MeV in inverse kinematics with the active target MAYA at GANIL. Using alpha scattering, the extracted isoscalar giant monopole resonance (ISGMR) centroid was determined to be 21.1 +/- 1.9 MeV and the isoscalar giant quadrupole resonance (ISGQR) to be 15.9 +/- 1.3MeV. Indications for soft isoscalar monopole and dipole modes are provided. Results obtained with both (alpha, alpha') and (d, d') probes are compatible. The evolution of isoscalar giant resonances along the Ni isotopic chain from Ni-56 to Ni-68 is discussed.</p
Reproductive Stage and Modulation of Stress-Induced Tau Phosphorylation in Female Rats
Chronic stress is implicated as a risk factor for Alzheimer's disease (AD) and other neurodegenerative disorders. While the specific mechanisms linking stress exposure and AD vulnerability have yet to be fully elucidated, our lab and others have shown that acute and repeated restraint stress in rodents leads to an increase in hippocampal tau phosphorylation (tau-P) and tau insolubility, a critical component of tau pathology in AD. Tau phosphorylation induced by a psychological stressor is reversible and is thought to be dependent on intact signaling through the type 1 corticotropin-releasing factor receptor, but how sex steroids or other modulators may also modulate this effect are unknown. A naturally occurring attenuation of stress response is observed in female rats at the end of pregnancy and throughout lactation. To test the hypothesis that decreased sensitivity to stress during lactation modulates stress-induced tau-P, cohorts of virgin, lactating, and weaned female rats were subjected to 30 minutes of restraint stress or no stress (control), and were sacrificed at 20 minutes or 24 hours after the episode. Exposure to restraint stress induced a significant decrease in tau-P in the hippocampus of lactating rats sacrificed 20 minutes after stress compared to lactating controls and virgins subjected to stress treatment. Lactating rats sacrificed 24 hours after exposure to restraint stress showed a significant increase in tau-P compared to the restraint-stressed lactating rats sacrificed only 20 minutes after stress exposure, expressing phosphorylation levels similar to control animals. Further, GSK3-α levels were significantly decreased in stressed lactating animals at both timepoints. This suggests a steep, yet transient stress-induced dephosphorylation of tau, influenced by GSK3, in the hippocampus of lactating rats
Neutron-proton pairing in the N=Z radioactive fp-shell nuclei 56Ni and 52Fe probed by pair transfer
The isovector and isoscalar components of neutron-proton pairing are
investigated in the N=Z unstable nuclei of the \textit{fp}-shell through the
two-nucleon transfer reaction (p,He) in inverse kinematics. The combination
of particle and gamma-ray detection with radioactive beams of Ni and
Fe, produced by fragmentation at the GANIL/LISE facility, made it
possible to carry out this study for the first time in a closed and an
open-shell nucleus in the \textit{fp}-shell. The transfer cross-sections for
ground-state to ground-state (J=0,T=1) and to the first (J=1,T=0) state
were extracted for both cases together with the transfer cross-section ratios
(0,T=1) /(1,T=0). They are compared with second-order
distorted-wave born approximation (DWBA) calculations. The enhancement of the
ground-state to ground-state pair transfer cross-section close to mid-shell, in
Fe, points towards a superfluid phase in the isovector channel. For the
"deuteron-like" transfer, very low cross-sections to the first (J=1,T=0)
state were observed both for \Ni\phe\, and \Fe\phe\, and are related to a
strong hindrance of this channel due to spin-orbit effect. No evidence for an
isoscalar deuteron-like condensate is observed.Comment: 7 pages, 4 figure
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