479 research outputs found
Detection of spin torque magnetization dynamics through low frequency noise
We present a comparative study of high frequency dynamics and low frequency
noise in elliptical magnetic tunnel junctions with lateral dimensions under 100
nm presenting current-switching phenomena. The analysis of the high frequency
oscillation modes with respect to the current reveals the onset of a
steady-state precession regime for negative bias currents above , when the magnetic field is applied along the easy axis of
magnetization. By the study of low frequency noise for the same samples, we
demonstrate the direct link between changes in the oscillation modes with the
applied current and the normalised low frequency (1/f) noise as a function of
the bias current. These findings prove that low frequency noise studies could
be a simple and powerful technique to investigate spin-torque based
magnetization dynamics
Nuevos sistemas de administración de agentes antiinflamatorios en el tratamiento de patologías oculares del segmento posterior
Las patologías del segmento posterior del ojo tienen consecuencias devastadoras en la visión y afectan a un gran número de personas en todo el mundo. Algunas cursan con inflamación, como la degeneración macular asociada a la edad (DMAE), la retinopatía diabética (RD), el edema macular diabético (EMD), el glaucoma y la uveítis, entre otras. La vía de administración tópica es la más utilizada para el tratamiento las patologías oftálmicas. Sin embargo, la dificultad de acceso de la sustancia al interior del globo ocular unido a la rapidez con la que los mecanismos de defensa del ojo eliminan la formulación administrada, hacen que se acuda al empleo de otras vías de administración, como la vía intraocular. A pesar de sus ventajas, las inyecciones intraoculares no están exentas de efectos adversos, y su principal inconveniente es que una única administración en bolus de la sustancia activa no es suficiente para el tratamiento. Por esta razón, desde hace algunos años se desarrollan sistemas intraoculares de liberación controlada de fármacos, capaces de mantener concentraciones de la sustancia activa en el lugar de acción durante periodos de tiempo prolongados. Gracias a estos dispositivos se puede reducir el número de inyecciones y, en consecuencia, los efectos adversos asociados
Marco de caracterización y cálculo de las métricas de calidad de los componentes web para el desarrollo de aplicaciones de usuario final
En la Web 2.0, donde usuarios finales sin grandes conocimientos de programación pueden interactuar y crear aplicaciones web utilizando componentes publicados en Internet, ofrecidos por una gran variedad de proveedores de servicio. La selección de estos componentes requiere de un análisis exhaustivo por parte de los usuarios sobre las propiedades de estos componentes en referencia a su calidad.
En este proyecto, se presentan dos modelos de calidad según una estructura jerárquica, uno para componentes web como elementos autónomos y otro para componentes utilizados en aplicaciones de mashup, basado en un análisis de la emergente Web 2.0. Además, se define una herramienta de medición y anotación de calidad para los distintos niveles de los modelos. Estas herramientas pretenden ser un útil instrumento para los desarrolladores y usuarios de componentes y mashups.---ABSTRACT---In the Web 2.0, where end users without a technical programming background can interact and develop web applications leveraging web components published on the Internet, offered by a great diversity of service providers. This component selection requires an exhaustive analysis by these end users based on the requirements of these components related to their quality.
In this work, two quality models are presented according to a hierarchical structure, one for web components as independent elements and another one for web components as parts of web mashup applications, based on an analysis of the emerging Web 2.0. In addition, a measuring and write down quality framework is defined to weigh the quality of all the levels of the models. These tools intend to provide a useful instrument to components and mashup developers and end users
Magnetoelastic coupling in La2/3Sr1/3MnO3 thin films on SrTiO3
Clamping of epitaxial La2/3Sr1/3MnO3 (LSMO) magnetic thin films on SrTiO3 (STO) substrates is shown to promote a clear modification of their magnetic properties at the STO cubic-tetragonal transition. Two distinct mechanisms triggered by the STO transition, namely magnetic domain pattern reconstruction and creation of regions within the magnetically soft LSMO with enhanced magnetic anisotropy, are proposed to be behind the observed anomalous magnetic responses at low ac-magnetic field and at high dc-field, respectively. The persistence of these anomalies in LSMO films as thick as 220 nm shines new light into the magnetoelastic coupling mechanisms across interfaces
Health Benefits of Heat-Killed (Tyndallized) Probiotics: An Overview
Nowadays, the oral use of probiotics is widespread. However, the safety profile with the use of live probiotics is still a matter of debate. Main risks include: Cases of systemic infections due to translocation, particularly in vulnerable patients and pediatric populations; acquisition of antibiotic resistance genes; or interference with gut colonization in neonates. To avoid these risks, there is an increasing interest in non-viable microorganisms or microbial cell extracts to be used as probiotics, mainly heat-killed (including tyndallized) probiotic bacteria (lactic acid bacteria and bifidobacteria). Heat-treated probiotic cells, cell-free supernatants, and purified key components are able to confer beneficial effects, mainly immunomodulatory effects, protection against enteropathogens, and maintenance of intestinal barrier integrity. At the clinical level, products containing tyndallized probiotic strains have had a role in gastrointestinal diseases, including bloating and infantile coli-in combination with mucosal protectors-and diarrhea. Heat-inactivated probiotics could also have a role in the management of dermatological or respiratory allergic diseases. The reviewed data indicate that heat-killed bacteria or their fractions or purified components have key probiotic effects, with advantages versus live probiotics (mainly their safety profile), positioning them as interesting strategies for the management of common prevalent conditions in a wide variety of patients´ characteristics
Adaptive activities for inclusive learning using multitouch tabletops: An approach
Proceedings of the International Workshop on Personalization Approaches in Learning Environments. Girona, Spain, July 15, 2011.Also published online by CEUR Workshop Proceedings (CEUR-WS.org, ISSN 1613-0073)People with cognitive disabilities have some difficulties with
memory, literacy skills, attention and problem solving. Computers and
specifically, adaptation mechanisms can be used to improve their learning. The
adaptation allows fitting the learning process to each user. This paper presents a
proposal to adapt learning activities while people are interacting using
multitouch tabletops. The adaptation mechanism takes into account structural
aspects, content adaptation and the interaction provided.This work has been funded by the Spanish Government (ASIES Project - Ministerio de Ciencia e Innovación de España, TIN2010-17344). The D2-Player has been funded by Fundación Sindrome de Down Madrid
Perceptions concerning intergenerational education from the perspective of participants
This article presents an evaluation of an intergenerational education experience at the University of
Castilla-La Mancha (Spain). For this evaluation, following a review of the literature regarding the
state of the issue, we undertake an analysis of benefits and disadvantages from the perspective of the
participants. Among the benefits we find that the majority of those questioned would repeat the program,
and that classroom atmosphere improved notably. Participants listed the exceptional nature of
the program and the teachers needing to make methodological adjustments to improve the experience
(the pace of teaching, adaptation to the profile of the participants) among the disadvantages.Depto. de Trabajo Social y Servicios SocialesFac. de Trabajo SocialTRUEpu
Channel Selection in Uncoordinated IEEE 802.11 Networks Using Graph Coloring
[EN] One of the big challenges in decentralized Wi-Fi networks is how to select channels for the different access points (APs) and their associated stations (STAs) in order to minimize interference and hence maximize throughput. Interestingly enough, de facto standards in terms of uncoordinated channel selection are quite simple, and in many cases result in fairly suboptimal channel allocations. Here, we explore how graph coloring can be used to evaluate and inform decisions on Wi-Fi channel selection in uncoordinated settings. Graph coloring, in its most basic form, is a classic mathematical problem where colors have to be assigned to nodes in a graph while avoiding assigning the same color to adjacent nodes. In this paper, we modeled Wi-Fi uncoordinated channel selection as a graph coloring problem and evaluated the performance of different uncoordinated channel selection techniques in a set of representative scenarios of residential buildings. The results confirm some of the widely accepted consensus regarding uncoordinated channel selection but also provide some new insights. For instance, in some settings, it would be better to delegate the decision on which channel to use to transmit the STAs, rather than having the AP make the decision on its own, which is the usual way.This publication is part of Project TED2021-131387B-I00 funded by MCIN/AEI/10.13039/501100011033 and by the European Union "NextGenerationEU"/PRTR and of Project PID2021-123168NB-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER, UE. Ivan Marsa-Maestre and David Orden are partially funded by Project SB-PLY/19/180501/000171 of the Junta de Comunidades de Castilla-La Mancha and FEDER and by Project WiDAI (CM/JIN/2021-004) of the Comunidad de Madrid and University of Alcala. Jose Manuel Gimenez-Guzman, Ivan Marsa-Maestre, and David Herranz-Oliveros are also funded by Project PID2019-104855RB-I00/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation. David Orden is also partially supported by Project PID2019-104129GB-I00/AEI/10.13039/501100011033 of the Spanish Ministry of Science and Innovation. The APC was funded by Project TED2021-131387B-I00 funded by MCIN/AEI/10.13039/501100011033 and by the European Union "NextGenerationEU"/PRTR.Gimenez-Guzman, JM.; Marsá-Maestre, I.; De La Hoz, E.; Orden, D.; Herranz-Oliveros, D. (2023). Channel Selection in Uncoordinated IEEE 802.11 Networks Using Graph Coloring. Sensors. 23(13). https://doi.org/10.3390/s23135932231
Low temperature oxide desorption in GaAs (111)A substrates
The aim of this work is to study oxide removal processes on GaAs (111) A substrates previous to epitaxial growth. We have studied conventional thermal desorption and processes based on the reduction of surface oxides by deposition of gallium, indium and exposure to atomic hydrogen. We have determined substrate temperatures (Ts) for optimum oxide removal in epi-ready substrates by the different studied processes: Ts = 540 °C for thermal desorption, Ts = 505 °C for indium deposition and Ts = 400 °C for oxide desorption by exposure to atomic hydrogen. All these processes allow for a subsequent good quality epitaxial growth. These results cannot be directly extended to oxide removal in grown samples that have been exposed to air outside the growth chamber. In this case, we have found that only indium deposition and exposure to atomic hydrogen are compatible with regrowth processes.We acknowledge financial support from Spanish MINECO (Grant TEC2011-29120-C05-04), and CAM (Grant S2009ESP-1503). Jesús Herranz acknowledges the JAE program for the funds.Peer Reviewe
Síntesis de mecanismos : aplicación al mecanismo de apertura de puertas de un autobús
En el estudio de mecanismos que se imparte en nuestra titulación, se enseña a realizar el análisis del movimiento de un mecanismo dado, donde sus medidas y componentes son datos.
En nuestro proyecto, haremos el proceso inverso, pretendemos encontrar un mecanismo que da lugar a un movimiento prescrito (ingeniería inversa). Esta situación se conoce como síntesis de mecanismos y puede presentar muchas alternativas de solución.Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, Expresión Gráfica en la Ingeniería, Ingeniería Cartográfica, Geodesia y Fotogrametría, Ingeniería Mecánica e Ingeniería de los Procesos de FabricaciónIngeniero Técnico Industrial, Especialidad en Mecánic
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