The influence of holes in the mechanical properties of EWT solar cells

EWT back contact solar cells are manufactured from very thin silicon wafers. These wafers are drilled by means of a laser process creating a matrix of tiny holes with a density of approximately 125 holes per square centimeter. Their influence in the stiffness and mechanical strength has been studied. To this end, both wafers with and without holes have been tested with the ring on ring test. Numerical simulations of the tests have been carried out through the Finite Element Method taking into account the non-linearities present in the tests. It's shown that one may use coarse meshes without holes to simulate the test and after that sub models are used for the estimation of the stress concentration around the holes

The Axion and the Goldstone Higgs

We consider the renormalizable $SO(5)/SO(4)$ $\sigma$-model, in which the Higgs particle has a pseudo-Nambu-Goldstone boson character, and explore what the minimal field extension required to implement the Peccei-Quinn symmetry (PQ) is, within the partial compositeness scenario. It turns out that the minimal model does not require the enlargement of the exotic fermionic sector, but only the addition of a singlet scalar: it is sufficient that the exotic fermions involved in partial compositeness and the singlet scalar become charged under Peccei-Quinn transformations. We explore the phenomenological predictions for photonic signals in axion searches for all models discussed. Because of the constraints imposed on the exotic fermion sector by the Standard Model fermion masses, the expected range of allowed axion-photon couplings turns out to be generically narrowed with respect to that of standard invisible axion models, impacting the experimental quest.Comment: 31 pages, 2 Figures. Description improved, results unchange

The Fermi Problem in Discrete Systems

The Fermi two-atom problem illustrates an apparent causality violation in Quantum Field Theory which has to do with the nature of the built in correlations in the vacuum. It has been a constant subject of theoretical debate and discussions during the last few decades. Nevertheless, although the issues at hand could in principle be tested experimentally, the smallness of such apparent violations of causality in Quantum Electrodynamics prevented the observation of the predicted effect. In the present paper we show that the problem can be simulated within the framework of discrete systems that can be manifested, for instance, by trapped atoms in optical lattices or trapped ions. Unlike the original continuum case, the causal structure is no longer sharp. Nevertheless, as we show, it is possible to distinguish between "trivial" effects due to "direct" causality violations, and the effects associated with Fermi's problem, even in such discrete settings. The ability to control externally the strength of the atom-field interactions, enables us also to study both the original Fermi problem with "bare atoms", as well as correction in the scenario that involves "dressed" atoms. Finally, we show that in principle, the Fermi effect can be detected using trapped ions.Comment: Second version - minor change

In vivo cell reprogramming to pluripotency: generating induced pluripotent stem cells in situ for tissue regeneration

Artificially induced changes of cell identity are increasingly attracting attention as potential strategies to regenerate diseased or injured tissues, but still rely heavily on ex vivo culture with the exception of a small number of in vivo transdifferentiation studies. The reprogramming of somatic cells to pluripotency in vivo is even less explored, partly due to fears of teratoma formation. In this thesis, we hypothesised that such twist in cell fate can be safely achieved in vivo provided that sufficient but transient levels of reprogramming factors are locally expressed. We also speculated that transiently pluripotent cells can be generated in different tissues, thanks to the universality of the Yamanaka reprogramming factors, and that they may contribute to replenish the injured site after an insult. In vivo induction of pluripotency was first described in the liver and later in the skeletal muscle of wild-type mice. In both scenarios, the fast but transient upregulation of pluripotency markers and downregulation of tissue-specific genes did not progress to teratoma formation. The in vivo reprogrammed hepatocytes were established as a cell line in vitro, the so-called in vivo induced pluripotent stem (i2PS) cells, and their pluripotency was confirmed at the molecular and functional levels. Clusters of in vivo reprogrammed cells within the skeletal muscle tissue were found to express pluripotency and myogenic progenitor markers and to re-integrate in the normal tissue architecture after a transient proliferative stage recapitulating events of normal postnatal myogenesis. Finally, in vivo reprogramming to pluripotency resulted in a modest enhancement of regeneration and functional rehabilitation in a model of skeletal muscle injury. In conclusion, this work not only provides proof-of-concept of safe in vivo cell reprogramming to pluripotency but also presents a thorough characterisation of the in vivo reprogrammed cells and supports the potential of such strategy to improve regeneration after injury

Spectral-analysis-surface-waves-method in ground characterization

The prediction of train induced vibration levels in structures close to railway tracks before track construction starts is important in order to avoid having to implement costly mitigation measures afterwards. The used models require an accurate characterization of the propagation medium i.e. the soil layers. To this end the spectral analysis of surface waves (SASW) method has been chosen among the active surface waves techniques available. As dynamic source a modal sledge hammer has been used. The generated vibrations have been measured at known offsets by means of several accelerometers. There are many parameters involved in estimating the experimental dispersion curve and, later on, thickness and propagation velocities of the different layers. Tests have been carried out at the Segovia railway station. Its main building covers some of the railway tracks and vibration problems in the building should be avoided. In the paper these tests as well as the influence of several parameters on the estimated soil profile will be detailed

Asistencia farmacéutica a la prescripción para aproximar la práctica clínica a la evidencia científica

ObjetivoEl objetivo del presente estudio es valorar la utilidad de un programa de asistencia farmacéutica a la prescripción (AFP) en cuanto a la detección de problemas relacionados con los medicamentos.DiseñoRealizamos un estudio descriptivo de los hallazgos de este programa al cabo de 6 meses de rodaje.EmplazamientoEl trabajo fue realizado en 5 centros del Distrito Bahía-Cádiz de Atención Primaria.PacientesSe estudian todos los pacientes (499) incluidos a petición y criterio de su médico, que solicita asesoramiento sobre su farmacoterapia.IntervenciónImplantamos el programa de AFP en pacientes crónicos con dos finalidades básicas:1. Asistencial: detectar problemas relacionados con medicamentos y proponer soluciones individualizadas.2. Docente: aproximar los conocimientos en farmacoterapia aplicados en la práctica clínica a la evidencia científica disponible.Mediciones y resultadosNos centramos en la detección de aquellos problemas relacionados con medicamentos más frecuentes, con incidencia directa y relevante sobre la morbimortalidad. Detectamos 236 casos (47%) de posible mejora terapéutica con implicaciones importantes sobre morbilidad asociada, de los cuales 114 (23%) tenían también implicaciones sobre mortalidad. Un 56% de los pacientes recibía más de 4 medicamentos, polimedicación que podía reducirse fácilmente en un 43,5% de ellos, evitando la utilización de medicamentos de valor intrínseco no elevado.ConclusionesLa utilidad del programa resulta muy elevada al detectar numerosos problemas de gran relevancia clínica y aportar información que puede ser útil al médico para aproximar la farmacoterapia a la evidencia científica disponible.ObjectiveThe objective of this study is to assess the usefulness of a programme of attention to pharmaceutical prescriptions (APP) so as to detect medicine-related problems.DesignA descriptive study of the findings after six months operation of this programme.SettingFive primary care centres in the Bahía-Cádiz Area.PatientsAll the patients (499) who requested advice on their drug therapy and were included at the request and on the criterion of their doctor were studied.InterventionWe introduced the APP programme for chronic patients, with two basic aims:1. Care: to detect medicine-related problems and propose individual solutions.2. Teaching: to bring drug-therapy skills used in clinical practice into line with the scientific evidence available.Measurements and resultsWe focused on the detection of problems related to the most common medicines, with direct and relevant incidence on morbidity and mortality. We detected 236 cases (47%) of possible therapeutic improvement that had important implications for associated morbidity, of which 114 (23%) also had implications for mortality. 56% of the patients took more than 4 medicines, multiple medication that could easily be reduced in 43.5% of cases, so avoiding the use of medicines of low intrinsic value.ConclusionsThe programme was very useful, as numerous very clinically relevant problems were detected and information was gained that the doctor can use to bring drug therapy into line with the available scientific evidence

Hours and Wages: A Bargaining Approach

In a recent paper, Bick et al. (2022) show the presence of a hump-shaped relationship between hours and hourly wages with a maximum around 50 hours worked. We show that a model with fixed labor costs where workers and firms bargain in wages and hours can help explain this non-linear relationship. Also, a quantitative version of the model is able to match the empirical hourly-wage to hours worked relationship estimated by those authors for the US

Non-linear Higgs portal to Dark Matter

The Higgs portal to scalar Dark Matter is considered in the context of non-linearly realised electroweak symmetry breaking. We determine the dominant interactions of gauge bosons and the physical Higgs particle h to a scalar singlet Dark Matter candidate. Phenomenological consequences are also studied in detail, including the possibility of distinguishing this scenario from the standard Higgs portal in which the electroweak symmetry breaking is linearly realised. Two features of significant impact are: i) the connection between the electroweak scale v and the Higgs particle departs from the (v + h) functional dependence, as the Higgs field is not necessarily an exact electroweak doublet; ii) the presence of specific couplings that arise at different order in the non-linear and in the linear expansions. These facts deeply affect the Dark Matter relic abundance, as well as the expected signals in direct and indirect searches and collider phenomenology, where Dark Matter production rates are enhanced with respect to the standard portal

Child care costs, household liquidity constraints, and gender inequality

In a model with endogenous female labour supply and wages, we show that liquidity constraints that prevent households from buying child care generate an inefficiency and amplify gender gaps in the labour market. We evaluate the relative merits of paid maternity leave, child care subsidies, and government loans in mitigating liquidity constraints and promoting gender equality. While an extension in the duration of the leave has ambiguous effects, child care subsidies and loans in the form of child care vouchers remove the liquidity constraints and reduce gender gaps in participation and wages. We illustrate the mechanisms at play in a numerical example using Spanish data

Minivideos tutorials to reinforce the learning of basic concepts for an Automatic Control course

[EN] This work proposes an initiative to introduce and promote the use of screencasts as a supporting tool for learning basic concepts of automatic control in technical University Degrees. The contents developed are available in the Youtube canal named “Automatica”, grouped by conceptual blocks. This material has been shared with the students of the University of Malaga through the Virtual Campus of 13 subjects given by the Department of Systems Engineering and Automation during the academic courses 2017/2018 and 2018/2019. The results derived from opinion surveys taken by the students show the good acceptance of this type of material. On the other hand, the cross-referring data between the effective reproduction time and the students’ qualifications in knowledge tests designed ad-hoc reveal a direct relation between the time employed by the students watching the screencasts and an improvement in their academic performance.[ES] En este trabajo se presenta una iniciativa encaminada a introducir y fomentar el uso de los videotutoriales como herramienta de apoyo para el aprendizaje de los conceptos básicos del control automático en titulaciones universitarias técnicas. Los contenidos desarrollados, disponibles en el canal de YouTube denominado “Automática”, se han agrupado de acuerdo a los principales bloques conceptuales de la materia y han sido puestos a disposición del alumnado en el espacio del campus virtual de la Universidad de Málaga (UMA) asociado a 13 asignaturas impartidas por el Dpto. de Ingeniería de Sistemas y Automática de la UMA en los cursos académicos 2017/2018 y 2018/2019. Los resultados obtenidos a través de encuestas de opinión cumplimentadas por los estudiantes muestran la buena acogida de los mismos. Por otro lado, el cruce de los datos de uso (entendido como tiempo efectivo de reproducción) recogidos durante este periodo y las calificaciones obtenidas a través de pruebas de conocimiento diseñadas ad-hoc revelan la existencia de una relación entre el empleo del material desarrollado y la mejora del rendimiento académico de los estudiantes.Este trabajo ha sido financiado a través del Plan de Innovación Educativa de la Universidad de Málaga (convocatoria 2017/2019) bajo la referencia PIE17-090.Arevalo, V.; Vicente-Del-Rey, J.; Garcia-Morales, I.; Rivas-Blanco, I. (2020). Minivídeos tutoriales como apoyo al aprendizaje de conceptos básicos para un curso de Fundamentos de Control Automático. Revista Iberoamericana de Automática e Informática industrial. 17(2):107-115. https://doi.org/10.4995/riai.2020.12156OJS10711517