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

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