4,243 research outputs found
La investigación escolar en la construcción de explicaciones acerca de la transmisión de caracteres hereditarios. sistematización de la unidad didáctica ¡moscas!... a enseñar herencia
El presente trabajo expondrá el desarrollo significativo respecto a conceptos, procedimientos y actitudes referidos a la herencia de caracteres hereditarios, que alcanzaron los estudiantes del grado octavo del IEDIT Rodrigo de Triana, en un periodo de tres meses en el año 2008, durante el cual se ejecutó el diseño, aplicación y sistematización de la unidad didáctica ¡Moscas! a enseñar herencia. En esta experiencia educativa se adoptaron los postulados del Enfoque de Enseñanza por Investigación Dirigida y el instrumento metodológico de Investigación Acción, donde los estudiantes organizados en equipos de trabajo abordaron una pregunta problema para desarrollar una investigación escolar, bajo la atenta dirección de las docentes, quienes corroboraron un cambio procedimental, conceptual y actitudinal en los estudiantes del grado 803
Corso, un buldog con ansiedad por separación
Se describe un caso de ansiedad por separación en un Buldog Francés macho de 1,7 años de edad. Sus dueños acuden a la consulta, ya que Corso destroza todo cuando se queda solo en casa. En un primer momento fue el salón, en donde fue necesario realizar obras de reparación de los destrozos provocados por el paciente. En la actualidad es un pasillo, su nueva ubicación cuando está solo. El tratamiento se compuso de tres partes: terapia farmacológica consistente en Trankimazin 1mg 1/24h y Fluoxetina 20mg 1/24h, la modificación de su entorno y una modificación de conducta, facilitada por el propio tratamiento farmacológico. Siete meses después, tras varios seguimientos, Corso es dado el alta, prolongándole el tratamiento farmacológico de Fluoxetina, media dosis durante un mes más.Privateering is described to a case of separation anxiety in a French Bulldog of 1,7 years, called Corso. The owners go to the clinic because Corso destroys everything when left alone at home. Initially was the living room where they had to make repairs of damage caused by Corso. Currently is a corridor, its new location when left alone. Treatment consisted of three parts: first the pharmacological treatment Trankimazin 1mg 1/24h and Fluoxetina 20mg 1/24h, then changing his environment and also a behavior modification helped by the pharmalogical treatment. Seven months later, and after several follow-ups, Corso was medical discharged but the pharmacological treatment was maintained for a month with half dose of Fluoxetina
Experimental signature of initial quantum coherence on entropy production
We report the experimental quantification of the contribution to
non-equilibrium entropy production that stems from the quantum coherence
content in the initial state of a qubit exposed to both coherent driving and
dissipation. Our experimental demonstration builds on the exquisite
experimental control of the spin state of a nitrogen-vacancy defect in diamond
and is underpinned, theoretically, by the formulation of a generalized
fluctuation theorem designed to track the effects of quantum coherence. Our
results provide significant evidence of the possibility to pinpoint the
genuinely quantum mechanical contributions to the thermodynamics of
non-equilibrium quantum processes.Comment: 5+5 pages, 4+2 figures, RevTeX4-
A revised distance to IRAS 162932422 from VLBA astrometry of associated water masers
IRAS 16293-2422 is a very well studied young stellar system seen in
projection towards the L1689N cloud in the Ophiuchus complex. However, its
distance is still uncertain with a range of values from 120 pc to 180 pc. Our
goal is to measure the trigonometric parallax of this young star by means of
HO maser emission. We use archival data from 15 epochs of VLBA observations
of the 22.2 GHz water maser line. By modeling the displacement on the sky of
the HO maser spots, we derived a trigonometric parallax of mas,
corresponding to a distance of pc. This new distance is in
good agreement with recent values obtained for other magnetically active young
stars in the L1689 cloud. We relate the kinematics of these masers with the
outflows and the recent ejections powered by source A in the system.Comment: 14 pages, 6 tables, 8 figures. Accepted to be published in Astronomy
\& Astrophysic
The Ising model and planar N=4 Yang-Mills
The scattering-matrix for planar Yang-Mills with N=4 supersymmetry relies on
the assumption that integrability holds to all orders in perturbation theory.
In this note we define a map from the spectral variables x^{\pm},
parameterizing the long-range magnon momenta, to couplings in a two-dimensional
Ising model. Under this map integrability of planar N=4 Yang-Mills becomes
equivalent to the Yang-Baxter equation for the two-dimensional Ising model, and
the long-range variables x^{\pm} translate into the entries of the Ising
transfer matrices. We explore the Ising correlation length which equals the
inverse magnon momentum in the small momentum limit. The critical regime is
thus reached for vanishing magnon momentum. We also discuss the meaning of the
Kramers-Wannier duality transformation on the gauge theory, together with that
of the Ising model critical points.Comment: 24 pages. v2: References added and minor typos correcte
Electrodeposition of Indium on W and Cu electrodes in the Deep Eutectic Solvent choline chloride-ethylene glycol (1:2).
Producción CientíficaA procedure for drying the deep eutectic solvent (DES) choline chloride - ethylene glycol, ChCl-EG (1:2), based on the use of molecular sieves has been developed, being the final water content of the electrolyte 145±5 ppm.
In this dried DES, the stability of InCl and InCl3 as well as the electrochemical behaviour of their solutions has been investigated using electrochemical techniques, X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). Experiments performed under a N2 atmosphere show that InCl3, dissolved in the rich chloride media as InClp 3-p, is reduced on a tungsten electrode to indium metal via only one electrochemical step.
Conversely, InCl undergoes the following disproportionation reaction when dissolved in the eutectic ChCl-EG (1:2)
3InCl(s) + (p − 3)Cl− ⇌ 2In(0) + InClp − 3 p
generating In(0) and giving place to identical electrochemical signals as those obtained after the addition of InCl3 to the DES.
On a tungsten electrode, nucleation and crystal growth of In plays an important role in the electrodeposition process. Chronoamperometric results were consistent with instantaneous three dimensional nucleation on a finite number of active sites with diffusion controlled growth of the nuclei, whatever the applied overpotential and temperature. Mass transport towards the electrode is a diffusion process, and the following empirical expression for the temperature dependence of the diffusion coefficient was calculated.
LnD = −(3.58 ± 0.22)–(3665 ± 76) T − 1
The electro-reduction of In(III) solutions was also investigated at a copper substrate. The resulting cyclic
voltammograms evidenced the formation of In-Cu intermetallic compounds. Hence, In-Cu alloy films were obtained by continuous potentiostatic electrolysis and intensiostatic pulse electrolysis. The obtained samples, characterized by XRD and SEM, revealed the formation of the metastable CuIn phase that could be transformed into Cu11In9 by thermal annealing.Consejería de Educación of the Junta de Castilla y León Project VA171U14 for financial support. S. García, also thanks the youth employment operative programme (European Social Fund, ESF, and youth employment initiative, YEI)
Innermost stable circular orbits around magnetized rotating massive stars
In 1998, Shibata and Sasaki [Phys. Rev. D 58, 104011 (1998)] presented an
approximate analytical formula for the radius of the innermost stable circular
orbit (ISCO) of a neutral test particle around a massive, rotating and deformed
source. In the present paper, we generalize their expression by including the
magnetic dipole moment. We show that our approximate analytical formulas are
accurate enough by comparing them with the six-parametric exact solution
calculated by Pach\'on et. al. [Phys. Rev. D 73, 104038 (2006)] along with the
numerical data presented by Berti and Stergioulas [MNRAS 350, 1416 (2004)] for
realistic neutron stars. As a main result, we find that in general, the radius
at ISCO exhibits a decreasing behavior with increasing magnetic field. However,
for magnetic fields below 100GT the variation of the radius at ISCO is
negligible and hence the non-magnetized approximate expression can be used. In
addition, we derive approximate analytical formulas for angular velocity,
energy and angular momentum of the test particle at ISCO.Comment: 8 pages, 3 figure
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