PT-symmetry broken by point-group symmetry

We discuss a PT-symmetric Hamiltonian with complex eigenvalues. It is based on the dimensionless Schr\"{o}dinger equation for a particle in a square box with the PT-symmetric potential $V(x,y)=iaxy$. Perturbation theory clearly shows that some of the eigenvalues are complex for sufficiently small values of $|a|$. Point-group symmetry proves useful to guess if some of the eigenvalues may already be complex for all values of the coupling constant. We confirm those conclusions by means of an accurate numerical calculation based on the diagonalization method. On the other hand, the Schr\"odinger equation with the potential $V(x,y)=iaxy^{2}$ exhibits real eigenvalues for sufficiently small values of $|a|$. Point group symmetry suggests that PT-symmetry may be broken in the former case and unbroken in the latter one

Phenomenology Tools on Cloud Infrastructures using OpenStack

We present a new environment for computations in particle physics phenomenology employing recent developments in cloud computing. On this environment users can create and manage "virtual" machines on which the phenomenology codes/tools can be deployed easily in an automated way. We analyze the performance of this environment based on "virtual" machines versus the utilization of "real" physical hardware. In this way we provide a qualitative result for the influence of the host operating system on the performance of a representative set of applications for phenomenology calculations.Comment: 25 pages, 12 figures; information on memory usage included, as well as minor modifications. Version to appear in EPJ

Basic Principles of Hybrid Alkaline Cements

A line of research of particular interest being pursued at this time is the development of new cements known as blended or hybrid alkaline cements. These cements form when blends containing low proportions of cement and high proportions (60-70 %) of mineral additions (such as blast furnace slag, fly ash or  metakaolin) are alkali activated. The reaction products precipitating in these systems are very complex and actually comprise a mix of gels: C?(A)?S?H type gels (similar to the gels obtained during cement hydration, but with aluminium in their composition) and (C,N)?A?S?H gels (similar to the N?A?S?H gels obtained during the alkaline activation of aluminosilicates, but with calcium in their composition). The prevalence of one or the other gel depends on a number of factors, including the concentration of the initial species in the solution, type of activator used, pH values and reaction time. The paper reviews the fundamental chemistry governing these new systems and the activation mechanisms involved.  It also analyses the nature of the reaction products formed and their compatibility under different reaction conditions

Motorized circular rail with RGB-D sensor on cart for physical rehabilitation

This paper introduces a motorized circular rail managing the movement of two carts equipped with an RGB-D sensor each. The proposal is aimed at continuously tracking a person who is undergoing a series of physical rehabilitation exercises from two different viewpoints to monitor if the exercises are being correctly conducted. More concretely, this work offers all details of the trajectory calculation for safe movement of both carts on the motorized circular rail. Then, two study cases are presented to show the efficiency of the control algorithms implemented.AEI - Agencia Estatal de Investigação(TIN2016-79100-R)This work was partially supported by Ministerio de Ciencia, Innovación y Universidades, Agencia Estatal de Investigación (AEI) / European Regional Development Fund (FEDER, UE) under DPI2016-80894-R and TIN2016-79100-R grants

Una aproximación estadística al estudio de la carbonatación del hormigón

Carbonation is one of the factors that conditions reinforced concrete durability, while porosity is one of the parameters that determines the carbonation rate: as a rule, the greater the porosity, the higher the rate. While many papers have been published on the effect of CO2 penetration in the pore solutions of concretes prepared under different experimental conditions, the literature has yet to address the joint effect of the factors considered in concrete design, such as the water/cement (w/c) ratio, type of cement, type of aggregate and presence of admixtures. The present paper discusses the findings of a statistical study of the impact of the aforementioned factors on both system porosity and carbonation rate. The type of cement, individually and in its interaction with the rest of the factors, proved to be the major determinant in concrete carbonation.La carbonatación es uno de los factores que supedita la durabilidad del hormigón armado, siendo la porosidad uno de los parámetros que más condicionan la velocidad de carbonatación. Son muchos los trabajos que estudian el efecto de la penetración del CO2 en la solución de los poros de hormigones preparados bajo distintas condiciones experimentales, sin embargo, no se encuentran referencias que analicen de forma conjunta el efecto de ciertos factores como son la relación agua/cemento (a/c ratio), el tipo de cemento, el tipo de árido y la presencia de aditivos, normalmente consideradas a la hora de diseñar un hormigón. En este trabajo se discuten los resultados obtenidos tras realizar un estudio estadístico del efecto que tienen los factores previamente mencionados, tanto en la porosidad de estos sistemas como en su nivel de carbonatación. El cemento tanto de manera individual como en sus interacciones con el resto de los factores es el factor que mas afecta a la carbonatación del hormigón

Right-Sided Endocarditis Secondary to Aeromonas hydrophila: A Case Report

Right-sided endocarditis represents a distinct clinical condition observed in individuals with a history of parenteral drug use or those with implanted pacemakers or other intracardiac devices. Aeromonas infections, although uncommon in humans, particularly endocarditis cases, are exceedingly rare. Here, we report the case of a 72-year-old female with a medical history of arterial hypertension and chronic kidney disease undergoing hemodialysis via a tunneled permanent central venous catheter. She presented with chills and a fever of 38.3°C. Physical examination revealed a grade 3 protosystolic murmur at the tricuspid focus. Blood cultures from central and peripheral sites yielded growth of Aeromonas hydrophila. Transthoracic echocardiography demonstrated a fusiform, semi-mobile vegetation measuring 16 x 15 mm at the outlet of the superior vena cava, suggestive of endocarditis. Intravenous fluoroquinolones were initiated based on antibiogram results, leading to resolution of imaging findings after a 21-day treatment course

MapReduce-based Solutions for Scalable SPARQL Querying

The use of RDF to expose semantic data on the Web has seen a dramatic increase over the last few years. Nowadays, RDF datasets are so big and rconnected that, in fact, classical mono-node solutions present significant scalability problems when trying to manage big semantic data. MapReduce, a standard framework for distributed processing of great quantities of data, is earning a place among the distributed solutions facing RDF scalability issues. In this article, we survey the most important works addressing RDF management and querying through diverse MapReduce approaches, with a focus on their main strategies, optimizations and results

Corrosion Behaviour of a Highly Alloyed Austenitic Alloy UB6 in Contaminated Phosphoric Acid

The influence of temperature (20-80°C) on the electrochemical behaviour of passive films anodically formed on UB6 stainless steel in phosphoric acid solution (5.5 M H3PO4) has been examined by using potentiodynamic curves, electrochemical impedance spectroscopy, and Mott-Schottky analysis. UB6 stainless steel in contaminated phosphoric acid is characterised by high interfacial impedance, thereby, illustrating its high corrosion resistance. The obtained results show that the films behave as n-type and p-type semiconductors in the potential range above and below the flat band potential, respectively. This behaviour is assumed to be the consequence of the semiconducting properties of the iron oxide and chromium oxide regions which compose the passive film