1,552 research outputs found
Determinants of profitability in Spanish financial institutions. Comparing aided and non-aided entities
The last financial crisis has led to the greatest contribution of public funds ever made to Spanish banks. This paper studies why the need for support has been asymmetric, with not all of the institutions requiring aid. Based on profitability of assets (ROA), we determine using panel data econometric and logit response models the components of profit and loss accounts that generated profitability as well as the factors leading to some entities to ask for aid. The analyses show that before the beginning of the crisis there were significant differences between entities that needed aid and those that did not. The most profitable banks grounded their success in the traditional revenue components of financial institutions (such as margin on interest rates and commissions), as well as in revenues obtained from participated companies and extraordinary results. The model offers a tool to detect entities in difficulties in advance, reducing the financial and social costs of public interventions. The factors more impacting on profitability of Spanish institutions are also identifie
Thickness of the buccal bone wall and root angulation in the maxilla and mandible: an approach to cone beam computed tomography
Background: The objective of this paper is to anatomically describe the bone morphology in the maxillary and mandibular tooth areas, which might help in planning post-extraction implants. Methods: CBCT images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The thickness of the facial wall was measured at the crest, point A, 4mm below, point B, and at the apex, point C. The second parameter was the angle formed between the dental axis and the axis of the basal bone. Results: A total of 403 teeth were measured. In the maxilla, 89.4% of incisors, 93.94% of canines, 78% of premolars and 70.5% of molars had a buccal bone wall thickness less than the ideal 2mm. In the mandible, 73.5% of incisors, 49% of canines, 64% of premolars and 53% of molars had <1mm buccal bone thickness as measured at point B. The mean angulation in the maxilla was 11.67±6.37° for incisors, 16.88±7.93° for canines, 13.93±8.6° for premolars, and 9.89±4.8° for molars. In the mandible, the mean values were 10.63±8.76° for incisors, 10.98±7.36° for canines, 10.54±5.82° for premolars and 16.19±11.22° for molars. Conclusions: The high incidence of a buccal wall thickness of less than 2mm in over 80% of the assessed sites indicates the need for additional regeneration procedures, and several locations may also require custom abutments to solve the angulation problems for screw-retained crowns
Activation Energy of Hydrogen Adsorption on Pt(111) in Alkaline Media: An Impedance Spectroscopy Study at Variable Temperatures
The hydrogen evolution reaction is one of the most studied processes in electrochemistry, and platinum is by far the best catalyst for this reaction. Despite the importance of this reaction on platinum, detailed and accurate kinetic measurements of the steps that lead to the main reaction are still lacking, particularly because of the fast rate of the reaction. Hydrogen adsorption on Pt(111) has been taken as a benchmark system in a large number of computational studies, but reliable experimental data to compare with the computational studies is very scarce. To gain further knowledge on this matter, a temperature study of the hydrogen adsorption reaction has been carried out to obtain kinetic information for this process on Pt(111) in alkaline solution. This was achieved by measuring electrochemical impedance spectra and cyclic voltammograms in the range of 278 ≤ T ≤ 318 (K) to obtain the corresponding surface coverage by adsorbed species and the faradaic charge transfer resistance. From this data, the standard rate constant has been extracted with a kinetic model assuming a Frumkin-type isotherm, resulting in values of 2.60 × 10–7 ≤ k0 ≤ 1.68 × 10–6 (s–1). The Arrehnius plot gives an activation energy of 32 kJ mol–1. Comparisons are made with values calculated by computational methods and reported values for the overall HER, giving a reference frame to support future studies on hydrogen catalysis.This work was financially supported by the MINECO (Spain) project no. CTQ2016-76221-P. L.E.B. thanks the Generalitat Valenciana for funding from the Santiago Grisolia Program (no. GRISOLIAP/2017/181)
Trunk Appearance Perception Scale (TAPS) discrepancy between scoliosis children and their parents influence the SRS-22 secore
Late Bronze Age Hoard studied by PIXE
The hoards of metallic objects belonging to the Late European Bronze Age can be interpreted
differently depending on the type, number and composition of the artefacts. PIXE analysis has
been performed in nine items from the Hoard of Freixanda in Portugal comprising 4 socket
axes, a palstave axe, a ring, a chisel, a dagger, and a casting debris. Besides the composition
of the main matrix elements, that is Cu and Sn, the amount of trace elements of interest like,
As, Pb, Ni and Ag has been determined using this ion beam technique. The high tin content
alloy and the high purity of the metals from the Freixanda hoard are characteristic of the
Portuguese and Spanish Late Bronze Age metallurgy, supporting the idea of a regional
production
ExtracciĂłn electroquĂmica de cloruros del hormigĂłn armado: estudio de diferentes variables que influyen en la eficiencia del tratamiento
This paper reports the results of applying electrochemical chloride extraction (ECE) to a series of chloride-contaminated concrete specimens. Experimental conditions were varied to study the efficiency of this technique under different circumstances. The survey covered the possible relationship between efficiency and the location of the sampling point, current density, type of concrete and treatment intermittence. Experiments were also conducted with different reinforcement configurations used in standard structural members such as columns and beams to ascertain the impact of rebar geometry.Este documento aporta los resultados de investigaciones realizadas en diferentes estudios en los que se aplicĂł la tĂ©cnica de ExtracciĂłn ElectroquĂmica de Cloruros (EEC) a diferentes estructuras de hormigĂłn contaminado con cloruros. Se cambiaron las condiciones experimentales con el fin de estudiar la eficiencia de la misma en cada una de ellas. Se estudiĂł la dependencia con la posiciĂłn del punto de toma de las muestras, con la densidad de corriente aplicada, con el tipo de hormigĂłn utilizado y con las paradas realizadas en etapas intermedias del tratamiento. Para ver la influencia de la disposiciĂłn geomĂ©trica de las armaduras,se realizĂł una experiencia con tipos diferentes de disposiciones de las armaduras, correspondiente a componentes estructurales tĂpicos como los pilares y las vigas
Interstitial Ti for intermediate band formation in Ti-supersaturated silicon
We have analyzed by means of Rutherford backscattering spectrometry (RBS) the Ti lattice location and the degree of crystalline lattice recovery in heavily Ti implanted silicon layers subsequently pulsed laser melted (PLM). Theoretical studies have predicted that Ti should occupy interstitial sites in silicon for a metallic-intermediate band (IB) formation. The analysis of Ti lattice location after PLM processes is a crucial point to evaluate the IB formation that can be clarifyied by means of RBS measurements. After PLM, time-of-flight secondary ion mass spectrometry measurements show that the Ti concentration in the layers is well above the theoretical limit for IB formation. RBS measurements have shown a significant improvement of the lattice quality at the highest PLM energy density studied. The RBS channeling spectra reveals clearly that after PLM processes Ti impurities are mostly occupying interstitial lattice sites
Estudio didáctico interactivo de los estados de la materia EDIEMA
La falta de recursos tales como laboratorios y materiales asĂ como la peligrosidad de algunas prácticas, hacen que la enseñanza de la QuĂmica sea muy teĂłrica, cuando es una ciencia básicamente experimental. Por otra parte, la tendencia, en la docencia Universitaria, está cambiando desde el concepto de enseñanza del profesor al aprendizaje del alumno, es decir, el alumno ha de ser artĂfice de su propio aprendizaje, actuando de forma activa en al adquisiciĂłn de conocimientos y habilidades.
La aplicaciĂłn desarrollada: estudio didáctico interactivo de los estados de la materia (EDIEMA), pretende paliar el dĂ©ficit de recursos y ayudar al alumno en su autoaprendizaje, mediante un sistema tutorizado, ya que permite mostrar, con detalle, las propiedades fĂsicas de los tres estados de la materia, gases, lĂquidos y sĂłlidos, desde un punto de vista molecular, sin necesidad de disponer de laboratorios, material, etc. Este estudio se realiza mediante simulaciones en tres dimensiones de experimentos y propiedades relacionadas con los gases, lĂquidos y sĂłlidos, centrándose principalmente en el estado gaseoso, ya que es el más difĂcil de experimentar en un laboratorio.
El software consta de tres partes: tutorial, simulaciĂłn y ejercicios. En el tutorial se exponen los contenidos teĂłricos, en la simulaciĂłn se presentan las experiencias de laboratorio que dieron lugar a la formulaciĂłn de leyes. En el apartado de ejercicios se formulan cuestiones para la autoevaluaciĂłn del conocimiento adquirid
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