13,668 research outputs found
String solutions in Chern-Simons-Higgs model coupled to an axion
We study a d=2+1 dimensional Chern-Simons gauge theory coupled to a Higgs
scalar and an axion field, finding the form of the potential that allows the
existence of selfdual equations and the corresponding Bogomolny bound for the
energy of static configurations. We show that the same conditions allow for the
N=2 supersymmetric extension of the model, reobtaining the BPS equations from
the supersymmetry requirement. Explicit electrically charged vortex-like
solutions to these equations are presented.Comment: 11 pages, 3 figure
Mixed-mode impedance and reflection coefficient of two-port devices
From the point of view of mixed-mode scattering parameters, Smm, a two-port device can be excited using different driving conditions. Each condition leads to a particular set of input reflection and input impedance coefficient definitions that should be carefully applied depending on the type of excitation and symmetry of the two-port device. Therefore, the aim of this paper is to explain the general analytic procedure for the evaluation of such reflection and impedance coefficients in terms of mixed-mode scattering parameters. Moreover, the driving of a two-port device as a one-port device is explained as a particular case of a two-port mixed-mode excitation using a given set of mixed-mode loads. The theory is applied to the evaluation of the quality factor, Q, of symmetrical and non- symmetrical inductors.Ministerio de Innovación y Ciencia TEC2010-14825/MIC, TEC2010-21484Junta de Andalucía TIC-253
Study of the stress intensity factors in the bulk of the material with synchrotron diffraction
Artículo de Proceedings de Congreso Internacional Fatigue2017In this work we present the results of a hybrid experimental and
analytical approach for estimating the stress intensity factor. It uses the
elastic strains within the bulk obtained by synchrotron X-ray diffraction
data. The stress intensity factor is calculated using a multi-point overdeterministic
method where the number of experimental data points is
higher than the number of unknowns describing the elastic field
surrounding the crack-tip. The tool is tested on X-ray strain
measurements collected on a bainitic steel. In contrast to surface
techniques the approach provides insights into the crack tip mechanics
deep within the sample.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. The authors are grateful to the ESRF for ID15 beamtime awarded under MA-1483. Financial
support of Universidad de Malaga through Plan Propio, Junta de Andalucía through Proyectos de
Excelencia grant reference TEP-3244, Campus de Excelencia Internacional del Mar (CEIMAR)
and Ministerio de Economia y Competitividad through grant reference MAT2016-76951-C2-2-P is
also acknowledged. PJW acknowledges an ERC advanced grant
High magnification crack-tip field characterisation under biaxial conditions
This work presents a novel methodology for characterising fatigue cracks under biaxial conditions.The methodology uses high magnification Digital Image Correlation (DIC) technique for measuringdisplacement and strain crack-tip fields. By applying micro-speckle pattern on the metal surface it is possible toachieve high magnification for DIC technique. The speckles were created by electro-spray technique. Thevalidity of this novel technique is demonstrated by direct comparison with standard extensometermeasurements, under tension-compression and torsion conditions. In order to image the correct region, thenotch effect on the fatigue life was also evaluated
Saber hacer y hacer saber : la difusion de las innovaciones para la construccion de vivienda popular
Sobrecargas en crecimiento de grietas por fatiga biaxial
El presente trabajo se centra en el estudio de grietas de fatiga bajo cargas biaxiales. Se presenta una nueva metodología
para evaluar el efecto de las sobrecargas basada en la evaluación experimental del factor de intensidad de tensiones
efectivo y de la apertura de la grieta (Crack Opening Displacement, COD). El estudio se ha realizado en probetas
cilíndricas de acero de bajo contenido en carbono sometidas a cargas de tracción y torsión. Los datos experimentales se
han obtenido mediante la técnica de correlación de imágenes digitales. Se ha comparado la evolución de la grieta con y
sin sobrecarga. Además, se ha utilizado un procedimiento de detección de carga de apertura. Dicho procedimiento se
había desarrollado previamente en fatiga uniaxial para el caso biaxial. Dicho procedimiento permite poner de manifiesto
el cambio originado por un ciclo de sobrecarga.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Comportamiento cíclico de una acero St-52-3N: Influencia de los módulos de elasticidad en las estimaciones de vida a fatiga
Dada la dependencia de los módulos de elasticidad en los métodos de estimación de vida a fatiga, se analiza el
comportamiento cíclico y la variación de estos con el grado de deformación. En este estudio se llevan a cabo una serie de
experimentos de fatiga uniaxial en control de deformación, con R=-1, a bajo número de ciclos y a temperatura ambiente,
para caracterizar el comportamiento cíclico del acero al carbono St-52-3N. Se realizaron ensayos de fatiga uniaxial tanto
de tracción como de torsión.
Se compara los valores de los módulos de elasticidad monotónico y cíclico, además de los valores cíclicos
correspondientes a los segmentos de descarga y carga (E1 ,E2) (acordes con ISO/DIS 121106). Se pone de manifiesto la
variabilidad cometida al calcular el incremento de deformación plástica según el Método Estándar de ensayo que
utilicemos (BS/ISO, ASTM, AECMA) y que determinará en cada caso la estimación del módulo de elasticidad cíclicoUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tec
Xps Study of the Oxidation State of Uranium Dioxide
In this article we report an investigation of the oxidation state of uranium dioxide using X-Ray Photoelectron Spectroscopy, and by comparing to results obtained in previous studies. We find that uranium dioxide in powder appears to share its six valence electrons with the oxygen atoms to form crystalline UO3
Singular Character of Critical Points in Nuclei
The concept of critical points in nuclear phase transitional regions is
discussed from the standpoints of Q-invariants, simple observables and wave
function entropy. It is shown that these critical points very closely coincide
with the turning points of the discussed quantities, establishing the singular
character of these points in nuclear phase transition regions between
vibrational and rotational nuclei, with a finite number of particles.Comment: 12 pages, 7 figures, elsart, revised version, considerable changes
and addition
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