420 research outputs found
High-temperature mechanical behavior of polycrystalline yttrium-doped barium cerate perovskite
The high-temperature mechanical properties of the mixed ionic-electronic conductor perovskite BaCe0.95Y0.05O3-δ with average grain size of 0.40μm have been studied in compression between 1100 and 1300°C in air at different initial strain rates. The true stress-true strain curves display an initial stress drop, followed by an extended steady-state stage. As the temperature decreases and/or the strain rate increases, there is a transition to a damage-tolerant strain-softening stage and eventually to catastrophic failure. Analysis of mechanical and microstructural data revealed that grain boundary sliding is the primary deformation mechanism. The strength drop has been correlated with the growth of ultrafine grains during deformation, already present at grain boundaries and triple grain junctions in the as-fabricated material.Ministerio de Ciencia e Innovación MAT2009-13979-C03-0
The Limits of Tolerance in Public Universities
In this article, our aim is to reflect on the legitimate ways that religious
pluralism may be managed in the state-owned public university environment. To
do this, it will be necessary to take into consideration the essential characteristics
of the origin of the university. The second point in our work will be to clarify the
concept of tolerance and its difference from neutrality, which will allow us to carry
out the reflection and subsequent discussion with rigour. For our third point, we will
describe the essential characteristics of the religious conflicts that can be found in
our European universities and how they are being managed.
Following a critical analysis of these cases, we will present a proposal of criteria
to be used in evaluating the religious practices in state-owned public universities
based on the theory of discourse ethics. Finally, in the conclusion we will indicate
some new lines of research and the path that public institutions may follow in managing
religious conflict
The Limits of Tolerance in Public Universities
In this article, our aim is to reflect on the legitimate ways that religious pluralism may be managed in the state-owned public university environment. To do this, it will be necessary to take into consideration the essential characteristics of the origin of the university. The second point in our work will be to clarify the concept of tolerance and its difference from neutrality, which will allow us to carry out the reflection and subsequent discussion with rigour. For our third point, we will describe the essential characteristics of the religious conflicts that can be found in our European universities and how they are being managed. Following a critical analysis of these cases, we will present a proposal of criteria to be used in evaluating the religious practices in state-owned public universities based on the theory of discourse ethics. Finally, in the conclusion we will indicate some new lines of research and the path that public institutions may follow in managing religious conflict
Study of physico-chemical parameters in smallscale craft beer production
In this past decade, the craft beer market has been gaining importance from large national andinternational beer breweries, especially micro-breweries and brew pubs. The evidence of thiscompetition is the fact that many large companies’ advertisements remind the public that theirroots were originally a microbrewery (1,2).However, the smaller budget of microbreweries incomparison to large companies, requires greater efficiency because a big loss for a smallbusiness would be a significant cost which could affect the competitive power of the companyin the market.In our microbrewery we have been studying different physico-chemical parameters (pH anddensity between others), changing critical steps in the elaboration of the different craft beersand analysing which factors influence these parameters the most, with the objective of makingthe beer production much more efficient. At the same time, we are going to compare theseparameters between the different types of beers that we produce in the factory.Our results show that the pH is slightly more acidic in beers that use a lower proportion ofPilsen-type malts. In relation to density it seems to be the opposite, the higher of thisproportion of this type of malt, the higher the density. Furthermore, some correlation has beenobserved between the degree of milling and the density, with a higher degree of milling of thegrain the higher the density is in the wort which allows to use less malt for the same volume,something that can have beneficial economic repercussions.Another problem that we found in this kind of industries it's the contamination of the finalproduct. However, we have designed a plan for waste management that consists in all thecontaminated beer previously analysed, is distilled in an alembic that extracts the ethanol fromthis useless product, that could then be used to make different valuable alcoholic drinks (gins,vodkas, whiskies, liqueurs). The point of this waste management plan is to reduce the costs aswell as improve the efficiency. We observed that the higher the alcoholic strength of thesubstrate to be distilled the greater the alcoholic strength of the final product. At the same time,the higher the volume to distill the longer it takes to start producing the final product
Estado Nutricional y Hábitos Alimentarios de estudiantes de primero y segundo año de la carrera de nutrición de la UNAN- MANAGUA. Septiembre a Noviembre 2015
El presente estudio es de tipo Descriptivo, prospectivo de corte Transversal, tiene como Objetivo Evaluar el Estado Nutricional y Hábitos Alimentarios de estudiantes de primero y segundo año de la carrera de nutrición de la UNAN-MANAGUA. Septiembre a Noviembre del 2015. El método para recoger la información fue la encuesta donde se entrevistó a cada uno de los participantes, y para esto se diseñó un formulario con preguntas en correspondencia a los objetivos del estudio, ssiendo los principales hallazgos de este estudio que la edad más predominante entre los estudiantes de primero y segundo año es entre 17 a 21 años, la región de procedencia de los estudiantes tanto del sexo masculino como femenino provienen de la región del pacifico; en cuanto a la situación socio economica los estudiantes de segundo año son los que mayormente reciben beca con un porcentage del 10% (6 estudiantes), los estudiantes de segundo año son los que mayor ingreso económico poseen, tomando en cuenta que estos provienen de una familia de origen nuclear y este tipo de familia es el que mayor ingreso económico aportan en el hogar debido a que los padres de familia son los que trabajan para mejorar la economía familiar. La frecuencia con la que los alumnos compran alimentos en la universidad es diariamente con 11 estudiantes con un porcentaje de (18%), y en relación al gasto de dinero con la compra de alimentos es de más de cien córdobas a la semana.
En relación al estado nutricional de los estudiantes 26 estudiantes de segundo año y 21 de primer año se encuentra en normo peso, sin embargo 6 estudiantes de primer año son los que mayor problema presentan de sobre peso y un 1% de los estudiante se encuentra en obesidad. Y en cuanto a hábitos alimentarios , la relación entre el tiempo de comida que realizan los estudiante al día con el tiempo de comida que consume más alimento, 21 estudiantes realizan tres de comida al día y mayormente consumen alimentos en el almuerzo, 18 estudiantes consumen más alimentos en el almuerzo pero realizan más de tres tiempos de comida. 10 estudiantes correspondientes a (17%) realizan dos tiempos de comida y el tiempo que consumen más alimentos es en el almuerzo. 28 Estudiantes de primero y 26 de segundo año consumen más alimento en el hogar que en la universidad.
¨ Estado Nutricional y Hábitos Alimentarios de estudiantes de primero y segundo En relación entre el consumo de comidas rápidas con el año que cursa el estudiante, los alumnos de primer año con un (45%) son los que más consumen comidas rápidas debido a que aún no tienen el conocimiento sobre el daño que provoca el consumo de este tipo de comidas y así mismo un 40% de los alumnos de segundo año
Modeling of an Overactuated Vehicle in Simscape Multibody for the Characterization of Suspension and Steering Actuation Systems.
Overactuated systems are increasingly among us. They are used for applications in vehicles, aeronautics and robotics, among others [1, 2]. These systems have a number of advantages, among which we can mention that there are multiple (or infinite) solutions for a given problem. More specifically, in the case of overactuated vehicles, similar states of the system can be achieved
in many different ways. These systems are still under development, especially in the field of vehicle dynamics. For example, there are various steer-by-wire algorithms, when the steering of the vehicles is independent, or brake blending strategies. In this work, a part of an overactuated vehicle is designed and validated. This multiphysics model allows to know the plant of the system in much more depth in order to develop control algorithms. More specifically, by modeling the delay of the systems and the nonlinear relationships inherent to multibody systems, much more accurate predictive control can be performed. These results allow a previous validation of the control algorithms in the test platform vehicle being manufactured and developed by the research group, greatly accelerating the control process of each of the overactuated systems of the vehicle.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Strategic Orientation of Mexican Family-owned Businesses and Its Influence on Corporate Social Responsibility Practices
The aim of this article was to determine whether the strategic orientation of family-owned businesses influences Corporate Social Responsibility (CSR) practices. For this purpose, a questionnaire was administered to a sample of 245 family-owned businesses in the southern part of the southeastern Mexican state of Quintana Roo. Variables attributed to CSR measurements were environment, society, employees, and customers, as well as business-level strategies of prospector, analyzer, defender, and reactor as defined by Miles and Snow. Results showed that family-owned businesses with a strategic orientation as prospector and analyzer have higher development levels of CSR practices, reactor businesses demonstrated lower development levels of CSR practices. Prospector and analyzer businesses tend to be product developers and innovators in their respective markets
FUNDAMENTOS TEÓRICOS DEL PROCESO ENSEÑANZA-APRENDIZAJE DE LA GEOMETRÍA ESPACIAL
THEORETICAL FUNDAMENTALS OF THE TEACHING-LEARNING PROCESS OF SPACE GEOMETRY
RESUMEN
La presente investigación busca realizar un acercamiento a los fundamentos teóricos del proceso enseñanza – aprendizaje de la geometría espacial, lo que le facilita al docente incidir positivamente en la calidad del proceso, en función de lograr en los estudiantes la adquisición de conocimientos y el desarrollo de las habilidades del pensamiento geométrico espacial. Adentrarse en el estudio del proceso de enseñanza – aprendizaje de la geometría espacial en la Educación Preuniversitaria presupone dilucidar los referentes teóricos más generales del mismo en el contexto de la Didáctica General, para luego penetrar en las particularidades que adquiere en el ámbito de esta Educación. La aplicación esencial de este proceso se da a través de la relación entre los distintos componentes: objetivos, contenidos, métodos, medios, formas y evaluación. En la formación de los estudiantes, las habilidades adquieren un papel preponderante dentro del contenido, quedando el conocimiento y los valores subordinados a las habilidades y destrezas que se relacionan con el pensamiento geométrico espacial.
PALABRAS CLAVE: Habilidades; Pensamiento geométrico espacial; Proceso enseñanza–aprendizaje.
ABSTRACT
The present research seeks to make an approach to the theoretical foundations of the teaching - learning process of spatial geometry, which facilitates the teacher to positively influence the quality of the process, in order to achieve in students the acquisition of knowledge and the development of the skills of spatial geometric thinking. Entering the study of the teaching - learning process of spatial geometry in Pre - university Education presupposes elucidating the more general theoretical references of the same in the context of General Didactics, and then penetrate the particularities that it acquires in the scope of this Education. The essential application of this process occurs through the relation between the different components: objectives, contents, methods, means, forms and evaluation. In the formation of the students, the skills acquire a preponderant role within the content, being the knowledge and the values subordinate to the abilities and skills that are related to the spatial geometric thought.
KEYWORDS: Skills; Geometric spatial thinking; Teaching-learning process
ESTRATEGIA DIDÁCTICA PARA EL DESARROLLO DE LAS HABILIDADES DEL PENSAMIENTO GEOMÉTRICO ESPACIAL
En el artículo se describe una estrategia didáctica para el desarrollo de las habilidades del pensamiento geométrico espacial, que se aplicó con adolescentes de duodécimo grado. Para realizar la investigación de la que se deriva el artículo se utilizaron métodos de los niveles teórico, empírico y matemático estadístico, lo que posibilitó la sistematización teórica de tendencias, premisas y principios, así como la concreción práctica de la propuesta. La estrategia didáctica que se propone favorece desde la dirección del aprendizaje el desarrollo de habilidades del pensamiento geométrico espacial
On-line learning applied to spiking neural network for antilock braking systems
Computationally replicating the behaviour of the cerebral cortex to perform the control tasks of daily life in a human being is a challenge today. First, … Finally, a suitable learning model that allows adapting neural network response to changing conditions in the environment is also required. Spiking Neural Networks (SNN) are currently the closest approximation to biological neural networks. SNNs make use of temporal spike trains to deal with inputs and outputs, thus allowing a faster and more complex computation. In this paper, a controller based on an SNN is proposed to perform the control of an anti-lock braking system (ABS) in vehicles. To this end, two neural networks are used to regulate the braking force. The first one is devoted to estimating the optimal slip while the second one is in charge of setting the optimal braking pressure. The latter resembles biological reflex arcs to ensure stability during operation. This neural structure is used to control the fast regulation cycles that occur during ABS operation. Furthermore, an algorithm has been developed to train the network while driving. On-line learning is proposed to update the response of the controller. Hence, to cope with real conditions, a control algorithm based on neural networks that learn by making use of neural plasticity, similar to what occurs in biological systems, has been implemented. Neural connections are modulated using Spike-Timing-Dependent Plasticity (STDP) by means of a supervised learning structure using the slip error as input. Road-type detection has been included in the same neural structure. To validate and to evaluate the performance of the proposed algorithm, simulations as well as experiments in a real vehicle were carried out. The algorithm proved to be able to adapt to changes in adhesion conditions rapidly. This way, the capability of spiking neural networks to perform the full control logic of the ABS has been verified.Funding for open access charge: Universidad de Málaga / CBUA
This work was partly supported by the Ministry of Science and Innovation under grant PID2019-105572RB-I00, partly by the Regional Government of Andalusia under grant UMA18-FEDERJA-109, and partly by the University of Malaga as well as the KTH Royal Institute of Technology and its initiative, TRENoP
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