Methods for Characterizing Multiphase Magnetocaloric Materials

This thesis is aimed to study the characteristics of thermomagnetic phase transitions and the resulting magnetocaloric effect in multiphase magnetocaloric materials, which is a very common scenario in the research of the magnetocaloric effect and can lead to complex situations that need to be properly approached. On the one hand, composites that combine various phases with Curie transitions close to each other are interesting and highly studied as they can lead to an enhanced refrigerant capacity with respect to the pure phases while keeping a large enough response. In this thesis, newly developed Gd + Gd7Pd3 composites are presented as a case in which the mentioned improvement of the refrigerant capacity is achieved. This intentional situation of overlapping Curie transitions has been used for the development of a method for the deconvolution of the magnetocaloric responses by means of the scaling laws of the magnetocaloric effect. On the other hand, materials exhibiting magnetostructural transformation (first-order phase transition) can also show the Curie transitions of the phases (second-order phase transition), where the phase transitions of different type can be concurrent. This situation is approached using Heusler alloys undergoing magnetostructural transformation located close to the Curie transitions of the martensitic and austenitic phases. The competing effect of both types of phase transitions in this case is investigated by experimental and analytical methods. The deconvolution method used for the composites is successfully applied here, enabling the subtraction of the Curie transition to the total response. It has to be noted that these situations of overlapping phase transitions can also occur unintentionally (i.e., due to the presence of impurities during synthesis). Therefore, the developed methods can also be used in these situations to know the effect of additional phase transitions and to gauge the actual response of the desired phase. Additionally, it has also been shown how the overlapping Curie transitions of the phases affect the hysteretic signature of the alloys undergoing magnetostructural transformation. This study is addressed through the emerging Temperature first-order reversal curves (TFORC) method for the study of magnetocaloric materials, using again Heusler alloys as a model case. This part combines experimental results with results from the modelling of the thermomagnetic behavior of the material. This has enabled a direct correlation between the characteristics of the thermomagnetic behavior of the alloys and the features of the TFORC distributions. Finally, the emerging topic of using polymer-based composites for the 3D printing of functional parts is addressed. Here, the main existing problem lies in the fabrication of uniform composite materials that allow the 3D printing of parts with predictable and repeatable functionality without relying on industrial techniques. A novel manufacturing method of polymer-based filaments containing functional fillers is proposed. Soft-magnetic steel particles have been used to manufacture polymer-based magnetic composites as proof of concept of the validity of the method. Once validated, the method is used to manufacture polymer-based magnetocaloric composites for additive manufacturing. The relatively simple method provides highly homogeneous filaments that preserve the magnetic functionality of the fillers. However, the property of the polymeric matrix is significantly affected by the addition of the metallic fillers, which has an important influence on the processability parameters both for the extrusion and printing

Selecting brand elements - a theoretical model for developing brand personality

This study presents a theoretical framework for start-ups to correctly manage the elements of their brand and develop their brand personality. It highlights the importance of brand personality in connecting with the intended audience and offers evidence-based guidelines for selecting appropriate brand elements, such as color, name, and font, to achieve desired goals. The research methodology involved several key steps, including the development of a theoretical model called "Brand Personality Process Management" through a comprehensive review of the relevant literature. This model aims to illustrate the correct process of creating a new brand by taking advantage of potential growth areas and provides a framework for conveying specific personality traits through different brand elements. The reliability of this model was verified through the participation of two focus groups. In conclusion, this study offers valuable information on effective branding strategies for start-ups seeking to establish themselves in competitive markets.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Estudio comparativo de sistemas de siembra en maíz, en Loudima, República del Congo

Este trabajo experimental fue llevado a cabo en Loudima, República del Congo entre los meses de mayo y septiembre de 2016. Tiene como objetivo determinar la estrategia de siembra óptima para el cultivo de maíz para futuras temporadas y conocer el impacto de marco de plantación y la densidad sobre el rendimiento en maíz. El experimento contaba con un total de dieciocho parcelas, nueve de ellas destinadas al sistema de siembra twin row (102.000 plantas/ha) y las otras nueve restantes al sistema conventional row (74.000 plantas/ha). Dentro de cada sistema de siembra, el experimento se realizó con tres variedades diferentes de maíz: PAN 12, LG 690 y Cameroon 51; y tres. El experimento consta de tres repeticiones para cada una de las variedades. El trabajo de campo fue completado con un análisis de la literatura y de la documentación existente sobre el tema, centrándose en la influencia de los sistemas de siembra y de la densidad sobre el rendimiento. Una vez recogidos los datos experimentales, se les sometió a un método estadístico para conocer qué variedad y bajo qué marco de plantación el rendimiento en maíz es mayor en esta zona. Para determinar la mejor alternativa se analiza si existe un efecto estadísticamente reseñable por parte del sistema de siembra y de la variedad utilizada sobre el rendimiento final de la plantación. Los resultados muestran un impacto estadísticamente reseñable por parte de la variedad y del sistema de siembra sobre el rendimiento. Como conclusión se seleccionó la variedad PAN12 y el sistema de siembra twin row como la combinación que mejores resultados ofrecería en posteriores cosechas -------------------------------------------------------------------------------- Trabajo Premiado PREMIO DE LA CÁTEDRA FERTIBERIA AL MEJOR TRABAJO ESCRITO TITULADO“ESTUDIO COMPARATIVO DE SISTEMAS DE SIEMBRA EN MAÍZ, EN LOUDIMA, REPÚBLICA DEL CONGO” de Alejandro Garcí

Adaptive transfer functions: improved multiresolution visualization of medical models

The final publication is available at Springer via http://dx.doi.org/10.1007/s00371-016-1253-9Medical datasets are continuously increasing in size. Although larger models may be available for certain research purposes, in the common clinical practice the models are usually of up to 512x512x2000 voxels. These resolutions exceed the capabilities of conventional GPUs, the ones usually found in the medical doctors’ desktop PCs. Commercial solutions typically reduce the data by downsampling the dataset iteratively until it fits the available target specifications. The data loss reduces the visualization quality and this is not commonly compensated with other actions that might alleviate its effects. In this paper, we propose adaptive transfer functions, an algorithm that improves the transfer function in downsampled multiresolution models so that the quality of renderings is highly improved. The technique is simple and lightweight, and it is suitable, not only to visualize huge models that would not fit in a GPU, but also to render not-so-large models in mobile GPUs, which are less capable than their desktop counterparts. Moreover, it can also be used to accelerate rendering frame rates using lower levels of the multiresolution hierarchy while still maintaining high-quality results in a focus and context approach. We also show an evaluation of these results based on perceptual metrics.Peer ReviewedPostprint (author's final draft

Classroom VR: un juego en RV para mejorar las capacidades comunicativas de profesores de secundaria

Trabajo de fin de grado del Grado en Ingeniería Informática, Facultad de Informática UCM, Departamento de Ingeniería del Software e Inteligencia Artificial, Curso 2019/2020Según los informes de prácticas de capacitación de los futuros maestros de educación secundaria, existen importantes deficiencias en las aptitudes de comunicación, necesarias para dirigir adecuadamente una clase. A pesar de la existencia de módulos relacionados con la comunicación en los maestros de enseñanza, no hay un aprendizaje real en esta área, y los estudiantes (los futuros profesores) expresan su temor cuando se trata de manejar una clase. Actualmente, la realidad virtual está presente en diferentes campos, como la medicina, la ingeniería, las humanidades, etc. Sus características (en particular la relativa a la creación de un entorno seguro, su ubicuidad y su alta capacidad de inmersión) la convierten en una tecnología ideal para la formación de habilidades de comunicación. Paralelamente, en los últimos diez años, los videojuegos han demostrado su eficacia como herramientas de aprendizaje, solos o combinados con otras estrategias pedagógicas. Por estas razones, consideramos la siguiente hipótesis: La realidad virtual en combinación con los videojuegos es, por un lado, un entorno eficaz para simular situaciones realistas relacionadas con la enseñanza secundaria y, por otro, un entorno ideal para practicar y aprender habilidades de comunicación para el aula. Teniendo esto en cuenta, hemos creado un entorno virtual que sirve como herramienta de formación para los futuros profesores de secundaria, para mejorar sus habilidades de comunicación y acostumbrarse a una clase real. Simula una clase de secundaria con estudiantes y funciona como un videojuego. Los estudiantes virtuales simulan el comportamiento de los estudiantes reales en el aula. Los futuros profesores empiezan el juego delante de la clase, como en la mayoría de las escuelas secundarias. La herramienta establece el fondo del juego, ofreciendo un contexto completo, acciones o comportamientos previos (por ejemplo, dos estudiantes han estado peleando toda la semana anterior). Después, el usuario tiene que reaccionar como en una situación real, manejando situaciones complicadas. Nuestro videojuego analiza en tiempo real el comportamiento del usuario (tono de voz, distancia entre el usuario y el o los estudiantes problemáticos y detección de vocabulario asertivo o negativo) y reacciona a través de los propios estudiantes, es decir, ofreciendo un comportamiento realista a las acciones del usuario. Somos optimistas sobre las posibilidades de nuestra herramienta en la formación de los profesores, ya que evita las costosas y complicadas prácticas logísticas en entornos reales. Los expertos consultados coinciden en el valor añadido que esta herramienta puede ofrecer a las prácticas en escuelas reales. El videojuego ofrece el entorno perfecto para aprender y comprender cómo manejar situaciones estresantes a través de una comunicación efectiva antes de enfrentarse a estudiantes reales.According to the reports of training practices from future secondaryschool teachers, there are significant shortcomings in the communication skills required to properly manage a class. Despite the existence of modules related to communication in the educational masters of teaching staff, there is no real learning in this area, and students (the future teachers) express their fear when it comes to dealing with a class. Currently, virtual reality is present in different fields, such as medicine, engineering, humanities, etc. Its characteristics (in particular the one concerning the creation of a safe environment, its ubiquity, and its high immersion capacity) turn it into an ideal technology for training communication skills. In parallel, in the last ten years, video games have proven their effectiveness as learning tools, alone or combined with other pedagogical strategies. For these reasons, we consider the following hypothesis: Virtual reality in combination with video games is, on the one hand, an effective environment for simulating realistic situations related to secondary education, and, on the other, an ideal environment to practice and learn communication skills for the classroom. Taking this into account, we have created a virtual environment that serves as a training tool for future secondary-school teachers, to improve their communication skills and get used to a real class. It simulates a secondary-school class with students and works as a video game. The virtual students work by simulating behaviors of real students in the classroom. Future teachers start the game in front of the class as in most secondary schools. The tool sets the game background, offering the complete context, actions, or previous behaviors (i.e., two students have been fighting all over the previous week). After, the user has to react as in a real situation, managing complicated situations. Our video game analyses in real-time the user’s behavior (voice tone, the distance between the user and the problematic student or students and detection of assertive or negative vocabulary) and reacts through the students themselves, i.e., offering realistic behavior to the user’s actions. We are optimistic about the possibilities of our tool on the teachers’training since it avoids the expensive and logistical complicated real environments practices. The experts consulted agree on the added value that this tool can offer to practices in real schools. The video game offers the perfect environment to learn and understand how to manage stressful situations through effective communication before facing real students.Depto. de Ingeniería de Software e Inteligencia Artificial (ISIA)Fac. de InformáticaTRUEunpu

A multi-projector CAVE system with commodity hardware and gesture-based interaction

Spatially-immersive systems such as CAVEs provide users with surrounding worlds by projecting 3D models on multiple screens around the viewer. Compared to alternative immersive systems such as HMDs, CAVE systems are a powerful tool for collaborative inspection of virtual environments due to better use of peripheral vision, less sensitivity to tracking errors, and higher communication possibilities among users. Unfortunately, traditional CAVE setups require sophisticated equipment including stereo-ready projectors and tracking systems with high acquisition and maintenance costs. In this paper we present the design and construction of a passive-stereo, four-wall CAVE system based on commodity hardware. Our system works with any mix of a wide range of projector models that can be replaced independently at any time, and achieves high resolution and brightness at a minimum cost. The key ingredients of our CAVE are a self-calibration approach that guarantees continuity across the screen, as well as a gesture-based interaction approach based on a clever combination of skeletal data from multiple Kinect sensors.Preprin

A comparison of neural and non-neural machine learning models for food safety risk prediction with European Union RASFF data.

European Union launched the RASFF portal in 1977 to ensure cross-border monitoring and a quick reaction when public health risks are detected in the food chain. There are not enough resources available to guarantee a comprehensive inspection policy, but RASFF data has enormous potential as a preventive tool. However, there are few studies of food and feed risk issues prediction and none with RASFF data. Although deep learning models are good prediction systems, it must be confirmed whether in this field they behave better than other machine learning techniques. The importance of categorical variables encoding as input for numerical models should be specially studied. Results in this paper show that deep learning with entity embedding is the best combination, with accuracies of 86.81%, 82.31%, and 88.94% in each of the three stages of the simplified RASFF process in which the tests were carried out. However, the random forest models with one hot encoding offer only slightly worse results, so it seems that in the quality of the results the coding has more weight than the prediction technique. Our work also demonstrates that the use of probabilistic predictions (an advantage of neural models) can also be used to optimize the number of inspections that can be carried out.pre-print301 K

Development of vectors and specialized Streptomyces strains for functional metagenomics

Motivation: Antimicrobial resistance (AMR) are one of the most important existing threats to public health aggravated by theoveruse of antimicrobials. It is estimated that the mortality from drug-resistance infections would increase up to 10 millions by2050. One of the major hurdles in microbial ecology is the inability to culture most of the microbial diversity present in ecosystemsunder laboratory conditions. The molecular analysis strategies used to examine the microbial community DNA, also known asthe metagenome, have been denoted as metagenomics techniques. With the use of functional metagenomics we are focus ourefforts on searching new antimicrobials. For the expression of genes from metagenomics DNA, Escherichia coli is the host mostused for function-based screening. However, the potential of Streptomyces as a surrogate host for the production of heterologousproteins has shown to be interesting for expression of proteins that are difficult to express in other bacterial host system.Methods: Basing on previous work, we are using a construction of specialized vectors with modified heterologous expressionsystem that incorporate viral components. The construction consist in the T7 RNA-polymerase gene (gene1), synthesized witha codon optimization for Streptomyces, that encodes the phage RNA-polimerase which is insensitive to many of the bacterialtermination signals. The gene1 expression is regulated by a inducible expression system based on PnitA-NitR regulatory system.To test that our system work properly, we have introduced in the cosmid for the metagenomic library construction, which isreplicative in Streptomyces, a reporter gene (xylE) whose gene product is a catechol dioxygenase which converts the colourlesssubstrate catechol to an intensely yellow oxidation product.Results: This part of the project aims to evaluate the efficience of heterologous expression measuring the catechol dioxygenaseactivity in solid and liquid media. In solid media we have seen that the Streptomyces colonies turned yellow when catechol wasapplied indicating that the expression system is working efficiently. The main objective of this project is to develop a metagenomiclibrary, with an improved heterologous expression, from DNA originating in several strains of Streptomyces in order to searchfor new antimicrobial resistance