X-ray reflectivity study of formation of multilayer porous anodic oxides of silicon.

The paper reports data on the kinetics of anodic oxide films growth on silicon in aqueous solutions of phosphoric acids as well as a study of the morphology of the oxides grown in a special regime of the oscillating anodic potential. X-ray reflectivity measurements were performed on the samples of anodic oxides using an intense synchrotron radiation source. They have a multilayer structure as revealed by theoretical fitting of the reflectivity data. The oscillations of the anodic potential are explained in terms of synchronized oxidation/dissolution reactions at the silicon surface and accumulation of mechanic stress in the oxide film

Porous silicon formation and electropolishing

Electrochemical etching of silicon in hydrofluoride containing electrolytes leads to pore formation for low and to electropolishing for high applied current. The transition between pore formation and polishing is accompanied by a change of the valence of the electrochemical dissolution reaction. The local etching rate at the interface between the semiconductor and the electrolyte is determined by the local current density. We model the transport of reactants and reaction products and thus the current density in both, the semiconductor and the electrolyte. Basic features of the chemical reaction at the interface are summarized in law of mass action type boundary conditions for the transport equations at the interface. We investigate the linear stability of a planar and flat interface. Upon increasing the current density the stability flips either through a change of the valence of the dissolution reaction or by a nonlinear boundary conditions at the interface.Comment: 18 pages, 8 figure

Aneurismal subarachnoid hemorrhage in a Chilean population, with emphasis on risk factors

<p>Abstract</p> <p>Background</p> <p>Subarachnoid Hemorrhage (SAH) is caused principally by the rupture of intracranial aneurisms. Important risk factors have been described such as age, sex, hypertension (HT) and season of the year, among others. The objective is to investigate the demographic characteristics and possible risk factors in a population of Chilean patients.</p> <p>Methods</p> <p>This retrospective study was based on the analysis of 244 clinical records of patients diagnosed with aneurismal SAH who were discharged from the Instituto de Neurocirugía ASENJO in Santiago, Chile.</p> <p>Results</p> <p>The mean age of patients was 49.85 years and the male:female ratio was 1:2.7. The signs and symptoms were not different between sexes; cephalea (85.7%) was predominant, followed by loss of consciousness, vomiting/nausea and meningeal signs. Risk factors included sex, age and HT. Concordant with other reports, the incidence of SAH was greatest in spring.</p> <p>Conclusions</p> <p>The demographic characteristics and risk factors observed in patients with aneurismal SAH treated in ASENJO were comparable to those of other populations. We were not able to conclude that tobacco and alcohol consumption were risk factors for this population.</p

Synchrotron x-ray reflectivity study of oxidation/passivation of copper and silicon.

Synchrotron x-ray-scattering technique studies of copper and silicon electrochemical interfaces are reported. These two examples illustrate the application of synchrotron x-ray techniques for oxidation, passivation, and dissolution of metals and semiconductors

Doppler Transcraneal en la Terapia de Realidad Virtual

El siguiente texto corresponde al abstract de uno de los póster del International Forum on Health Care and and Information Communication Technology (HICT) , celebrado en Barcelona, entre el 8 y el 10 de marzo de 2011. Or ganizado por el Laboratorio de Psicología y Tecnologia (LabPsiTec), de la Universidad Jaume I de Castellón y de la Universidad de Valencia; el Grupo de Psicología, Salud y Red (PSiNET) de la Universitat Oberta de Catalunya y el Centre for Research in Family Health, del IWK Health Centre, de Canadá. Se trata del primer foro interna cional de estas características, cuyo objetivo fundamental es crear un espacio común para investigadores, es tudiantes y profesionales del ámbito de la Salud y las Tecnologías de la Información y la Comunicación. Bajo el título Descubriendo la Amplia Gama de Usos de las TIC en la Salud, el Foro pretendía compartir conocimientos y experiencias de investigación para explorar cómo las TIC pueden ser utilizadas en el ámbito de la salud para evaluar, prevenir y gestionar las cuestiones relacionadas con la salud. La Fundación para la eSaludFeSalud, editora de la RevistaeSalud.com, quiso apoyar la celebración de este Foro internacional, mediante la edición en el número 26 de la publicación de los Astract de las conferencias, los pos ters y workshops presentados durante esta reunión científica, contribuyendo de esta forma a la divulgación de actividades científicas relacionadas con la eSalud. La RevistaeSalud.com es, por tanto, la publición científica oficial del HICT 2011