1,590 research outputs found

    Triethylphosphite as a network forming agent enhances in-vitro biocompatibility and corrosion protection of hybrid organic-inorganic sol-gel coatings for Ti6Al4V alloys

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    The biocompatibility and life of metallic implants can be enhanced through improving the biocompatibility and corrosion protection characteristics of the coatings used with these materials. In this study, triethylphosphite (TEP) was used to introduce phosphorus into organic-inorganic hybrid silica based sol gel coatings prepared using γ-methacryloxypropyltrimethoxysilane and tetramethylorthosilicate. Addition of TEP dramatically increased the rate of intermolecular condensation and resulted in materials showing greater cross linking. Protein (fibrinogen) uptake, osteoblast in vitro biocompatibility and corrosion resistance was enhanced in coatings containing TEP. Although higher concentrations of phosphorus supported the greatest improvement in biocompatibility, a compromise in the phosphorus concentration used would be required if corrosion resistance was most desirable parameter for optimisation. Films prepared by dip coating on Ti6Al4V alloys from these sols offer a promising alternative to wholly metallic prostheses

    AGRICULTURA Y MIGRACIÓN COLECTIVA EN LA REGIÓN MONTAÑA DE GUERRERO, MÉXICO

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    Objective: To describe the agricultural activity and forms of migration of agricultural laborers in the municipality of Tlapa de Comonfort, Guerrero.Design/methodology/approach: A questionnaire was applied to 108 migrants from 17 communities of the study municipality, for the descriptive analysis of the migratory process. The study variables considered sociodemographic characteristics, agricultural aspects and migratory aspects.Results: In the municipality of Tlapa de Comonfort, 100% of the interviewees migrated with their family. This way of migrating is very advantageous because all members of the family have the possibility of working, which represents greater economic income. The type of farming activity that they practice in their communities is subsistence agriculture, insufficient to cover the needs of the family.Study limitations/implications: The diversity of places of origin and the lack of a migrant registry make it difficult to apply random sampling.Findings/conclusions: The agricultural laborers of the municipality of Tlapa de Comonfort, Guerrero, migrate because the agricultural activity does not generate sufficient income for their survival and in the region there are no alternative sources of employment.Objetivo: Describir la actividad agropecuaria y las formas de migración de los jornaleros agrícolas en el municipio de Tlapa de Comonfort, Guerrero. Diseño/metodología/aproximación: Se aplicó un cuestionario a 108 migrantes de 17 comunidades del municipio de estudio, para el análisis descriptivo del proceso migratorio. Las variables de estudio consideraron características sociodemográficas, aspectos agropecuarios y aspectos migratorios.Resultados: En el municipio de Tlapa de Comonfort el 100% de los entrevistados migró con su familia. Esta forma de migrar es muy ventajosa porque todos los miembros de la familia tienen la posibilidad de trabajar, lo que representa mayores ingresos económicos. El tipo de actividad agropecuaria que practican en sus comunidades es de subsistencia, insuficiente para cubrir las necesidades de la familia.Limitaciones del estudio/implicaciones: La diversidad de los lugares de origen y la falta de un padrón de migrantes dificulta la aplicación de un muestreo aleatorio.Hallazgos/conclusiones: Los jornaleros agrícolas del municipio de Tlapa de Comonfort, Guerrero, migran porque la actividad agrícola no les genera los ingresos suficientes para su supervivencia y en la región no se tienen fuentes de empleo alternativos

    Preparación y caracterización de precursores mesoporosos de LiFePO4

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    II Encuentro sobre nanociencia y nanotecnología de investigadores y tecnólogos de la Universidad de Córdoba. NANOUC

    Blasts and shocks in the disc of NGC 4258

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    We present integral field spectroscopic observations of the central region of the active galaxy NGC 4258 obtained with the fibre IFU system INTEGRAL. We have been able to detect cold neutral gas by means of the interstellar NaD doublet absorption and to trace its distribution and kinematics with respect to the underlying disc. The neutral gas is blue-shifted with projected velocities in the 120--370 km/s range. We have also detected peculiar kinematics in part of the ionized gas in this region by means of a careful kinematic decomposition. The bipolar spatial distribution of the broader component is roughly coincident with the morphology of the X-ray diffuse emission. The kinematics of this gas can be explained in terms of expansion at very high (projected) velocities of up to 300 km/s. The observations also reveal the existence of a strip of neutral gas, parallel to the major kinematic axis, that is nearly coincident with a region of very high [SII]/Hα\alpha ratio tracing the shocked gas. Our observations are consistent with the jet model presented by \cite{wilsonetal01} in which a cocoon originating from the nuclear jet is shocking the gas in the galaxy disc. Alternatively, our observations are also consistent with the bipolar hypershell model of \cite{Sofue80} and \cite{SofueandVogler01}. On balance, we prefer the latter model as the most likely explanation for the puzzling features of this peculiar object.Comment: 7 pages, 10 colour figures. Accepted for publication in MNRAS

    Estudio del comportamiento electroquímico en baterías de litio de nanopartículas de Li2NiTiO4

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    III Encuentro sobre Nanociencia y Nanotecnología de Investigadores y Tecnólogos Andaluce

    Design of a case management model for people with chronic disease (Heart Failure and COPD). Phase I: modeling and identification of the main components of the intervention through their actors: patients and professionals (DELTA-ICE-PRO Study

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    Background Chronic diseases account for nearly 60% of deaths around the world. The extent of this silent epidemic has not met determined responses in governments, policies or professionals in order to transform old Health Care Systems, configured for acute diseases. There is a large list of research about alternative models for people with chronic conditions, many of them with an advanced practice nurse as a key provider, as case management. But some methodological concerns raise, above all, the design of the intervention (intensity, frequency, components, etc). Methods/Design Objectives: General: To develop the first and second phases (theorization and modeling) for designing a multifaceted case-management intervention in people with chronic conditions (COPD and heart failure) and their caregivers. Specific aims: 1) To identify key events in people living with chronic disease and their relation with the Health Care System, from their point of view. 2) To know the coping mechanisms developed by patients and their caregivers along the story with the disease. 3) To know the information processing and its utilization in their interactions with health care providers. 4) To detect potential unmet needs and the ways deployed by patients and their caregivers to resolve them. 5) To obtain a description from patients and caregivers, about their itineraries along the Health Care System, in terms of continuity, accessibility and comprehensiveness of care. 6) To build up a list of promising case-management interventions in patients with Heart Failure and COPD with this information in order to frame it into theoretical models for its reproducibility and conceptualization. 7) To undergo this list to expert judgment to assess its feasibility and pertinence in the Andalusian Health Care. Design: Qualitative research with two phases: For the first five objectives, a qualitative technique with biographic stories will be developed and, for the remaining objectives, an expert consensus through Delphi technique, on the possible interventions yielded from the first phase. The study will be developed in the provinces of Almería, Málaga and Granada in the Southern Spain, from patients included in the Andalusian Health Care Service database with the diagnosis of COPD or Heart Failure, with the collaboration of case manager nurses and general practitioners for the assessment of their suitability to inclusion criteria. Patients and caregivers will be interviewed in their homes or their Health Centers, with their family or their case manager nurse as mediator. Discussion First of a series of studies intended to design a case-management service for people with heart failure and COPD, in the Andalusian Health Care System, where case management has been implemented since 2002. Accordingly with the steps of a theoretical model for complex interventions, in this study, theorization and intervention modeling phases will be developed.This research was carried out with the support of one research grant, awarded by the Regional Health Ministry of Andalusia (Exp. 0222/2008

    Práctica de desarrollo de interfaces hardware/software para la monitorización del estado de un PC

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    Este artículo presenta una práctica laboratorio impartida mediante una metodología de aprendizaje basado en proyectos (ABP) [1] para dotar de la capacidad de diseñar y desarrollar un monitor del estado de un ordenador, integrado en un sistema empotrado que se comunica con una aplicación de escritorio, a nuestros alumnos de la asignatura de Diseño de Microcontroladores (DM) en el contexto del Máster en Ingeniería de Computadores y Redes. Esta práctica abarca la comunicación Hardware/ Software entre un microcontrolador con un núcleo Cortex-M4 y una aplicación software escrita en lenguaje C# usando el entorno Visual Studio Community 2015 a través de puertos series virtuales (VCP). Esta práctica está enfocada como un proyecto que los alumnos han de ir realizando desde cero, avanzando mediante la consecución de hitos, hasta conseguir obtener un sistema final. El sistema a desarrollar se divide en dos partes, por un lado tenemos un PC con un sistema operativo de la familia Windows, en el que se construye una aplicación visual mediante Windows Forms, la cual obtiene información del sistema de forma periódica y la envía al microcontrolador mediante comandos usando el puerto serie (USB o comunicación Bluetooth). Por otro lado tenemos un microcontrolador de la familia STM32 que dispone de un display LCD ejecutando una plataforma completamente libre, .NET Micro Framework, la cual recibe a través del puerto serie la información obtenida gracias a la aplicación software del PC y la muestra en la pantalla, obteniendo así una herramienta de monitorización del PC sin tener que estar conectado físicamente a éste. El desarrollo de este tipo de proyectos se añade la dificultad de la necesidad del uso de diferentes herramientas para el desarrollo del firmware y del software en paralelo, de manera incremental, y enfocadas para ámbitos de uso muy distintos. Esta práctica ha tenido una gran acogida por parte de los alumnos, ya que les ha servido de ejemplo del desarrollo de firmware para un microcontrolador usando la plataforma .NET MF y de su comunicación con el PC por medio de una aplicación visual.This manuscript presents a practical laboratory session imparted using a project-based learning methodology (PBL) to provide the capacity of designing and developing a computer status monitoring device, integrated in an embedded system that communicates with a desktop software tool, to our students in the Computer Engineering Master’s Degree. This practice session encompasses Hardware/ Software communication between a microcontroller with a Cortex-M4 kernel and a desktop software application through virtual COM ports (VCP) written in C# using Visual Studio Community 2015. This lab session is focused as a project that students must be making from scratch by achieving and completing some milestones to obtain a final functional system. The project is divided into two different parts. First, we have a Windows PC where a visual software application that gathers information from the system and sends it periodically to the microcontroller (USB or Bluetooth) has to be built using Windows Forms. On the other hand, we have a microcontroller from the STM32 family that has a 2.4’ LCD display executing .NET Micro Framework that receives the information obtained from the PC through the serial port and displays it in the screen. This way, students create a computer status monitoring tool that does not need to be connected physically to it to receive the information. The development of this project is added to the need of using different tools for firmware and software development, focused to very different fields of use. This practice has been well received by the students, because it has served as an example of the firmware development for a microcontroller using the .NET MF platform as well as the communication between the PC and the microcontroller using a visual software application

    A City Profile of Malaga: The Role of the Port-City Border throughout Historical Transformations

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    The relationships Malaga has established with its port have changed over the centuries, conjuring up a variety of scenarios and circumstances. The past and present are closely linked phenomena in this case study where the porosity of the port‐city fabric has marked the city’s development and constitutes a key issue in the current and future challenges it faces. Malaga provides a particularly interesting example of a post‐industrial city that has reopened its port to its inhabitants’ acclaim while maintaining port activity. However, the growth tourism has seen in recent years has come to dominate the local economy. Cruise ships have taken on a significant role and have brought about important changes in the dynamics and flows between the port and the city, unsettling the balance between the two. This profile explores port‐city development through the lens of boundaries and flows, demonstrating how their dynamics have determined Malaga’s spatial, functional, and social development over time and how they continue to do so to this day. This article reviews the transformations the city has undergone and its future opportunities to achieve a balanced and sustainable port‐city relationship

    Study of the thermal degradation of bioactive sol-gel coatings for the optimization of its curing process

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    A set of materials has been prepared by sol-gel process containing different quantities of hydroxyapatite (0, 2.5 and 5% HAp w/w) using as silica precursors glycidyloxypropyltrimethoxysilane (GPTMS) and triethoxyvinylsilane (VTES). In order to optimize the curing process to obtain sintherized systems (inorganic network) or hybrid systems (organic&-inorganic) a TG and FTIR studies have been developed and degradation kinetic triplet parameters were obtained (the activation energy, pre-exponential factor, and function of degree of conversion). The kinetic study was analyzed by means of an integral isoconversional non-isothermal procedure (model free), and the kinetic model was determined by the Coats&-Redfern method and through the compensation effect (IKR). All the systems followed the n = 6 kinetic model. The addition of HAp increases the thermal stability of the systems. The isothermal degradation was simulated from non-isothermal data, and the curing process could be defined to obtain the two types of materials. Temperature under 250 °C allows the formation of hybrids networks.Publicad
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