Speeding up antidynamical Casimir effect with nonstationary qutrits

The antidynamical Casimir effect (ADCE) is a term coined to designate the coherent annihilation of excitations due to resonant external perturbation of system parameters, allowing for extraction of quantum work from nonvacuum states of some field. Originally proposed for a two-level atom (qubit) coupled to a single cavity mode in the context of nonstationary quantum Rabi model, it suffered from very low transition rate and correspondingly narrow resonance linewidth. In this paper we show analytically and numerically that the ADCE rate can be increased by at least one order of magnitude by replacing the qubit by an artificial three-level atom (qutrit) in a properly chosen configuration. For the cavity thermal state we demonstrate that the dynamics of the average photon number and atomic excitation is completely different from the qubit's case, while the behavior of the total number of excitations is qualitatively similar yet significantly faster.Comment: 9 pages, 4 figure

Charged Hydrogenic, Helium and Helium-Hydrogenic Molecular Chains in a Strong Magnetic Field

A non-relativistic classification of charged molecular hydrogenic, helium and mixed helium-hydrogenic chains with one or two electrons which can exist in a strong magnetic field $B \lesssim 10^{16}$G is given. It is shown that for both $1e-2e$ cases at the strongest studied magnetic fields the longest hydrogenic chain contains at most five protons indicating to the existence of the $\rm{H}_5^{4+}$ and $\rm{H}_5^{3+}$ ions, respectively. In the case of the helium chains the longest chains can exist at the strongest studied magnetic fields with three and four \al-particles for $1e-2e$ cases, respectively. For mixed helium-hydrogenic chains the number of heavy centers can reach five for highest magnetic fields studied. In general, for a fixed magnetic field two-electron chains are more bound than one-electron ones.Comment: 32 pages, 2 figures, 9 table

El cuidado de enfermería: una visión integradora en tiempos de crisis

Nowadays, there exist several organizations of humanitarian movements all over the world which try to fight against the dehumanization expressions; however there still exists the presence of situations which are the reasons of pain in the world. That is why we must construct a better and civilized world in which people worries about the quality of life instead of accumulating statistical numbers .Care is a common feature of all human beings. Therefore, human care is recognized as a universal concept, inherent in humanity. Heidegger, the philosopher for excellence of care, recognizes that this is "an ontological constitution that is always underlying to all what the human beings begin, project and make." Nursing as a profession of social nature tries that its staff , under an humanistic perspective , helps the person interested in care to reinforce his /her abilities and /or to minimize imbalances in her /his state of health .That is why it recognizes the human beings as a complex , mysterious and structured in several dimensions being that range from the organic to the spiritual, from the tangible to the intangible , including the social and historical aspect , which defines it as a being of permanent relationships with himself and the world. Under this point of view, nursing tries to recognize that the cared person is a unique entity which has attributes such as: awareness, intellect, dignity, emotions, feelings and knowledge. Therefore, the nursing care assumes a comprehensive and humanistic dimension of the human being whose subjectivity is structured by his experiences ,meanings , feelings , emotions , intuitions ,and reasoning .Existen diversas organizaciones y movimientos humanitarios a nivel mundial que tratan de luchar contra las expresiones de deshumanización, sin embargo continúa la presencia de situaciones que son causas de dolor en el mundo, por lo que debemos constituir una sociedad para que el mundo sea civilizado, vivir por la calidad de vida y no por acumular cifras estadísticas. El cuidado es una característica común de todos los seres vivos. Por consiguiente, el cuidado humano se  reconoce como un concepto universal, inherente a la humanidad. Heidegger,  el filósofo por excelencia del cuidado, reconoce que éste  es “una constitución ontológica, siempre subyacente a todo lo que el ser humano emprende, proyecta y hace”. Enfermería como profesión de naturaleza social intenta que su personal, bajo una óptica humanista, ayude a la persona solicitante  del cuidado a reforzar  potencialidades y/o minimizar desequilibrios en su estado de salud, por ello reconoce al ser humano como  un ser complejo, misterioso, estructurado por  diversas dimensiones que van de lo orgánico a lo espiritual, de lo tangible  a lo intangible; con inclusión del  aspecto social e histórico, que lo define como un ser de interrelaciones permanentes consigo mismo y el mundo. Bajo esta perspectiva, en enfermería, se procura reconocer que la persona cuidada es una entidad única, poseedora de atributos: conciencia, intelecto, dignidad, emociones, sentimientos y saberes,  por lo tanto, el cuidado en enfermería  asume una dimensión humanista y comprensiva  del ser, cuya subjetividad está estructurada por sus vivencias y significados, sentimientos, emociones, intuiciones, razonamientos.

The HeH+HeH^+ molecular ion in a magnetic field

A detailed study of the low-lying electronic states {}^1\Si,{}^3\Si,{}^3\Pi,{}^3\De of the $\rm{HeH}^+$ molecular ion in parallel to a magnetic field configuration (when \al-particle and proton are situated on the same magnetic line) is carried out for $B=0-4.414\times 10^{13}$ G in the Born-Oppenheimer approximation. The variational method is employed using a physically adequate trial function. It is shown that the parallel configuration is stable with respect to small deviations for \Si-states. The quantum numbers of the ground state depend on the magnetic field strength. The ground state evolves from the spin-singlet {}^1\Si state for small magnetic fields $B\lesssim 0.5$ a.u. to the spin-triplet {}^3\Si unbound state for intermediate fields and to the spin-triplet strongly bound $^3\Pi$ state for $B \gtrsim 15$ a.u. When the $\rm{HeH}^+$ molecular ion exists, it is stable with respect to a dissociation.Comment: 13 pages, 5 figures, 4 table

A worldsheet for Kerr

We show that the Newman-Janis shift property of the exact Kerr solution can be interpreted in terms of a worldsheet effective action. This holds both in gravity, and for the single-copy $\sqrt{\text{Kerr}}$ solution in electrodynamics. At the level of equations of motion, we show that the Newman-Janis shift holds also for the leading interactions of the Kerr black hole. These leading interactions are conveniently described using chiral classical equations of motion with the help of the spinor-helicity method familiar from scattering amplitudes

Evolution of an elliptical bubble in an accelerating extensional flow

Mathematical models that describe the dynamical behavior of a thin gas bubble embedded in a glass fiber during a fiber drawing process have been discussed and analyzed. The starting point for the mathematical modeling was the equations presented in [1] for a glass fiber with a hole undergoing extensional flow. These equations were reconsidered here with the additional reduction that the hole, i.e. the gas bubble, was thin as compared to the radius of the fiber and of finite extent. The primary model considered was one in which the mass of the gas inside the bubble was fixed. This fixed-mass model involved equations for the axial velocity and fiber radius, and equations for the radius of the bubble and the gas pressure inside the bubble. The model equations assumed that the temperature of the furnace of the drawing tower was known. The governing equations of the bubble are hyperbolic and predict that the bubble cannot extend beyond the limiting characteristics specified by the ends of the initial bubble shape. An analysis of pinch-off was performed, and it was found that pinch-off can occur, depending on the parameters of the model, due to surface tension when the bubble radius is small. In order to determine the evolution of a bubble, a numerical method of solution was presented. The method was used to study the evolution of two different initial bubble shapes, one convex and the other non-convex. Both initial bubble shapes had fore-aft symmetry, and it was found that the bubbles stretched and elongated severely during the drawing process. For the convex shape, fore-aft symmetry was lost in the middle of the drawing process, but the symmetry was re-gained by the end of the drawing tower. A small amount of pinch-off was observed at each end for this case, so that the final bubble length was slightly shorter than its theoretical maximum length. For the non-convex initial shape, pinch-off occurred in the middle of the bubble resulting in two bubbles by the end of the fiber draw. The two bubbles had different final pressures and did not have fore-aft symmetry. An extension of the fixed-mass model was considered in which the gas in the bubble was allowed to diffuse into the surrounding glass. The governing equations for this leaky-mass model were developed and manipulated into a form suitable for a numerical treatment

Experiência em pesquisa: a trajetória do Grupo de Pesquisa em usuários de informação

Se comparte la trayectoria del Grupo de Investigación sobre Usuarios de la Información perteneciente a la cátedra “Usuarios de la Información” de la Escuela de Bibliotecología, Facultad de Filosofía y Humanidades de la Universidad Nacional de Córdoba, Argentina. Se muestra la evolución, desarrollo y crecimiento del mismo, así como de las investigadoras que lo integran. Se exponen y explican brevemente las investigaciones realizadas y la investigación en curso, partiendo de la teoría de la sociedad de las tecnologías de la información (Castells, 2002), de las que aportaron a la evolución de la alfabetización en información (Kunhlthau - 1987; Bruce - 1997, Eisenberg - 1998, SCONUL - 1999; ACRL - 1989; Webber y Johnson - 2002; Walter - 2007 y UNESCO - 2008). Como así también las teorías de Aprendizaje de Bruner, Ausubel y Vygotsky. Se finaliza la presente ponencia realizando una proyección sobre el futuro de este grupo tomando como referencia los frutos resultantes de las investigaciones que marcaron esta trayectoria

Assembly of spheroid-dominated galaxies in the EAGLE simulation

Context. Despite the insights gained in the last few years, our knowledge about the formation and evolution scenario for the spheroid-dominated galaxies is still incomplete. New and more powerful cosmological simulations have been developed that together withmore precise observations open the possibility of more detailed study of the formation of early-type galaxies (ETGs).Aims. The aim of this work is to analyse the assembly histories of ETGs in a Λ-CDM cosmology, focussing on the archeologicalapproach given by the mass-growth histories.Methods. We inspected a sample of dispersion-dominated galaxies selected from the largest volume simulation of the EAGLE project.This simulation includes a variety of physical processes such as radiative cooling, star formation (SF), metal enrichment, and stellarand active galactic nucleus (AGN) feedback. The selected sample comprised 508 spheroid-dominated galaxies classified according totheir dynamical properties. Their surface brightness profile, the fundamental relations, kinematic properties, and stellar-mass growthhistories are estimated and analysed. The findings are confronted with recent observations.Results. The simulated ETGs are found to globally reproduce the fundamental relations of ellipticals. All of them have an innerdisc component where residual younger stellar populations (SPs) are detected. A correlation between the inner-disc fraction and thebulge-to-total ratio is reported. We find a relation between kinematics and shape that implies that dispersion-dominated galaxies withlow V/σ L (where V is the average rotational velocity and σ L the one dimensional velocity dispersion) tend to have ellipticity smallerthan ∼ 0.5 and are dominated by old stars. On average, less massive galaxies host slightly younger stars. More massive spheroidsshow coeval SPs while for less massive galaxies (stellar masses lower than ∼ 10 10 M ), there is a clear trend to have rejuvenated innerregions, showing an age gap between the inner and the outer regions up to ∼ 2 Gyr, in apparent contradiction with observationalfindings. We find evidences suggesting that both the existence of the disc components with SF activity in the inner region and theaccretion of satellite galaxies in outer regions could contribute to the outside-in formation history in galaxies with low stellar mass.On the other hand, there are non-negligible uncertainties in the determination of the ages of old stars in observed galaxies. Strongersupernova (SN) feedback and/or the action of AGN feedback for galaxies with stellar masses lower than 10 10 M could contribute toprevent the SF in the inner regions.Fil: Rosito, María Sol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigaciones Matemáticas "Luis A. Santaló". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Matemáticas "Luis A. Santaló"; ArgentinaFil: Tissera, P. B.. Universidad Andrés Bello; ChileFil: Pedrosa, Susana Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Rosas Guevara, Y.. Universidad Andrés Bello; Chile. Centro de Estudios de Física del Cosmo de Aragon; Españ