163 research outputs found

    Grado en Química: coordinación y seguimiento del curso 2014-15

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    En la red docente "Seguimiento del grado en Química", formada por los coordinadores de las comisiones de semestre de la Facultad de Ciencias y la coordinadora del grado en Química, se ha analizado la información extraída de las reuniones periódicas (al menos dos por semestre) de las ocho comisiones de semestre (correspondientes a los cuatro cursos del grado en Química). El objetivo es conseguir una coherencia tanto en la distribución de contenidos, como en las metodologías docentes y de evaluación de las materias que componen el plan de estudios del Grado en Química de la Universidad de Alicante. Los resultados de este trabajo están permitiendo identificar problemas y plantear propuestas de mejora en la organización docente de la titulación. El trabajo realizado por la red se está utilizando para elaborar el autoinforme para la reacreditación del grado en Química

    Olive Leaves as Biotemplates for Enhanced Solar-Light Harvesting by a Titania-Based Solid

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    Olive leaves (by-product from olive oil production in olive mills) were used as biotemplates to synthesize a titania-based artificial olive leaf (AOL). Scanning electron microscopy (SEM) images of AOL showed the successful replication of trichomes and internal structure channels present in olive leaves. The BET surface area of AOL was 52 m2·g−1. X-ray diffraction (XRD) and Raman spectra revealed that the resulting solid was in the predominantly-anatase crystalline form (7.5 nm average particle size). Moreover, the synthesis led to a red-shift in light absorption as compared to reference anatase (gap energies of 2.98 and 3.2 eV, respectively). The presence of surface defects (as evidenced by X-ray photoelectron spectroscopy, XPS, and electron paramagnetic resonance spectroscopy, EPR) and doping elements (e.g., 1% nitrogen, observed by elemental analysis and XPS) could account for that. AOL was preliminarily tested as a catalyst for hydrogen production through glycerol photoreforming and exhibited an activity 64% higher than reference material Evonik P25 under solar irradiation and 144% greater under ultraviolet radiation, (under voltage) UV

    Seguimiento del Grado en Química

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    Con la implantación del 4º curso del grado en Química, que se ha realizado en el presente curso académico, se han completado los cuatro cursos del grado. En la Facultad de Ciencias se han constituido ocho comisiones de semestre, en las que participan profesores de todos los departamentos que imparten docencia en la titulación y la Comisión de Grado, formada por los coordinadores de las comisiones de semestre que, a su vez, forman parte de una red docente para el seguimiento del grado. Desde estas comisiones se está realizando un intenso trabajo cooperativo cuyo objetivo es alcanzar una coherencia tanto en la distribución de contenidos, como en las metodologías docentes y de evaluación de las materias que componen el plan de estudios del Grado en Química de la Universidad de Alicante. La coordinación horizontal entre semestres de un mismo curso y la coordinación vertical entre cursos forman parte de las tareas que se desarrollan. Los resultados de este trabajo permiten identificar las deficiencias en el proceso de implantación y plantear posibles propuestas de mejora en la organización docente de la titulación

    Mechanochemical Synthesis of Nickel-Modified Metal–Organic Frameworks for Reduction Reactions

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    In this work, we report the incorporation of nickel oxide nanoparticles into a metal–organic framework (MOF) structure by a solvent-free mechanochemical strategy. In particular, the zirconium-based MOF UiO-66 was modified with different Ni loadings and characterized using complementary techniques including X-ray diffraction (XRD), N2 porosimetry and X-ray photoelectron spectroscopy (XPS). The catalytic potential of the as-prepared Ni/UiO-66 materials in the hydrogenation reaction of methyl levulinate using 2-propanol as hydrogen donor solvent has been investigated under flow conditions. Under optimized conditions, the 5%Ni/UiO-66 led to the best catalytic performance (70% yield, 100% selectivity to gamma-valerolactone), which could be attributed to the higher content of the Ni species within the MOF structure. The obtained results are promising and contribute to highlighting the great potential of MOFs in biomass upgrading processes, opening the path to the sustainable development of the chemical industry

    A Discussion about the Methodology to Validate the Correlations of Heat Transfer Coefficients and Pressure Drop during the Condensation in a Finned-Tube Heat Exchanger

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    As already demonstrated by others authors, when the performance of a heat exchanger is analyzed, a semi-empirical model allows getting good prediction of the experimental results provided that it is accompanied by the application of the suitable correlations for calculating heat transfer coefficients (HTC) and pressure drop (PD) in both refrigerant and air side. Many correlations for calculating these coefficients are available in literature, therefore choose the more suitable of them turns out to be not an easy task. This paper presents a discussion about the methodology to perform a comparison aimed to define the criterion for choosing the most suitable correlation to be used in a simulation model for prediction of heat exchangers performance in refrigeration systems. Differently from others works, where the results of each correlation are compared with those obtained by means specific experiments focused on the local phenomenon visualization, in this work the correlations are compared against the measurements of a complete finned-tube condenser integrated in a traditional air-to-water heat pump. The comparison has been carried out using a model able to discretize the heat exchanger through a finite volume method (FVM). The discussion is supported with a case study which was experimentally tested and numerically modeled. The condenser is a finned tube coil that characterized by two asymmetric circuits. The tube diameter is 7 mm and the fin pitch is 2.6 mm. The experimental test bench includes a single-speed 34.3 cm3 reciprocating-hermetic compressor, a plate evaporator and an electronic valve as expansion device. An accumulator allow adjusting the condenser sub-cooling. A specific test campaign has been designed in order to cover a wide range operating points of the condenser: different air velocities (from 1.5 m/s to 4 m/s), inlet temperatures (20-46°C) and sub-cooling (0-5-10°C) have been taken into account. All the correlations considered were programmed and simulated with the software IMST-ART. In order to avoid the overlapping of the effects of the different correlations, during the analysis of the two-phase flow, the heat transferred in the one-phase section of the exchanger and the air-side heat transfer coefficient were maintained constant. The analysis of air-side heat transfer coefficient and pressure drop was carried out in the same way but keeping constant the coefficients of the refrigerant side. Different accuracy parameters were defined in order to assist the final decision about which correlation is able to provide the best agreement with experimental data. The paper aims to present a discussion about the validation methodology, the analysis of the correlations impact on the model results rather than define the parameters to choose the best correlation

    La coordinacion de materias de economia en el Grado de Marketing e Investigación de Mercados

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    El objetivo del proyecto es conocer la posible existencia de solapamiento de los contenidos de las diversas asignaturas de economía que imparte el departamento de Economía e Historia Económica en el grado de Marketing y evaluar el grado de satisfacción del alumno con la metodología utilizada a fin de mejorar la misma. Para ello, se ha realizado una encuesta de elaboración propia a los alumnos matriculados entre los cursos académicos 2004-05 y 2008-09. Los resultados obtenidos nos permiten descartar un excesivo solapamiento de contenidos, tan solo el 10,6% de la muestra manifestó dicha opción, y para el 43,6% de los preguntados los contenidos de las asignaturas resultan complementarios. En cuanto a la metodología docente aunque no parece distar de la adecuada en función de las respuestas, un 60% considera que debería combinar las clases magistrales del profesor, con la preparación y posterior exposición por parte de los alumnos de contenidos teóricos y prácticos de las asignaturas .Sí manifiestan una excesiva carga teórica que dificulta en ocasiones la comprensión de las materias. En cuanto a la motivación del alumnado a partir del trabajo de los profesores, la respuesta supera una media de 3 en la escala de Likert, lo cual implica que no hay una clara desmotivación, aunque es susceptible de mejora al no encontraese con una media de 4The goal of this research is to determine if there exist overlapping contents among the different subjects of economics given by Economics and Economic History Department at the Marketing degree. In addition, we try to evaluate the student’s satisfaction with the methodology applied in the different subjects in the past, in order to improve it. To achieve these goals, we have carried out our own survey to the students along the academic years between 2004/2005 and 2008/2009. The main results can be summarised as follows: On the one hand, the existence of excessive common contents can be rejected since only the 10% of the sample suggests that such common contents exist. Moreover, for the 43,6% of the students, the content of the different subjects are complementary. On the other hand, as far as educational methodology is concerned, the answers given in the survey allow us to conclude that in general they have been satisfactory for the students. Nevertheless, more than the 60% of the sample considers that the methodology should combine the traditional lectures with personal work and later exposition of theoretical and practical contents of subjects by the students. Furthermore, students suggest that theoretical contents are excessive in comparison with the practical ones which can be an obstacle to understand the subjects. Concerning students’ motivation, on average the answer is over 3 in the Likert scale, which implies that, although there is not discouragement in relation to the subjects given by the Department, improvements can be done in this are

    Direct primary brown coal liquefaction via non-catalytic and catalytic co-processing with model, waste and petroleum-derived hydrogen donors

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    ABSTRACT: Direct coal liquefaction (DCL) seems to be a suitable way to convert low rank coals into liquid fuels, especially when problematic wastes are used together with this feedstock. It is also a solution to become energy independent for many countries which have significant coal resources and limited access to crude oil. The aim of this research was to investigate DCL process by the co-processing of brown coal with model-, petroleum- and waste-derived solvents. The brown coal with and without W, Fe and Mo metals supported on its surface was tested. Thirteen DCL tests with added hydrogen pressure were carried out in the autoclave. These tests were classified in two groups. First group covered reactions using model and petroleum-derived solvents (tetralin, 1-methylnaphthalene, light cycle oil (LCO), hydrotreated LCO, C9+ fraction and decalin) with non-impregnated brown coal. Then, LCO was chosen as solvent for carrying out three tests using the metals supported on coal. Finally, waste tires pyrolysis oil was used as a waste-derived solvent for other three tests with molybdenum supported on coal. For tests using LCO, the total amount of direct liquid and n-heptane soluble products was 20 wt% higher using metal covered brown coal in comparison to unmodified one. The test with the brown coal impregnated by 1% of molybdenum resulted in the best efficiency, thus this type of coal was chosen as a catalytic feedstock for the tests with waste tires pyrolysis oil.info:eu-repo/semantics/publishedVersio

    Selective expression of the neurexin substrate for presenilin in the adult forebrain causes deficits in associative memory and presynaptic plasticity

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    Presenilins (PS) form the active subunit of the gamma-secretase complex, which mediates the proteolytic clearance of a broad variety of type-I plasma membrane proteins. Loss-of-function mutations in PSEN1/2 genes are the leading cause of familial Alzheimer's disease (fAD). However, the PS/gamma-secretase substrates relevant for the neuronal deficits associated with a loss of PS function are not completely known. The members of the neurexin (Nrxn) family of presynaptic plasma membrane proteins are candidates to mediate aspects of the synaptic and memory deficits associated with a loss of PS function. Previous work has shown that fAD-linked PS mutants or inactivation of PS by genetic and pharmacological approaches failed to clear Nrxn C-terminal frag-ments (NrxnCTF), leading to its abnormal accumulation at presynaptic terminals. Here, we generated transgenic mice that selectively recreate the presynaptic accumulation of NrxnCTF in adult forebrain neurons, leaving unaltered the function of PS/gamma-secretase complex towards other substrates. Behavioral characterization identified selective impairments in NrxnCTF mice, including decreased fear-conditioning memory. Electro-physiological recordings in medial prefrontal cortex-basolateral amygdala (mPFC-BLA) of behaving mice showed normal synaptic transmission and uncovered specific defects in synaptic facilitation. These data functionally link the accumulation of NrxnCTF with defects in associative memory and short-term synaptic plasticity, pointing at impaired clearance of NrxnCTF as a new mediator in ADMinisterio de Ciencia, Innovación y Universidades (RTI2018-101886-B-100)Junta de Andalucía (PY18-823)Junta de Andalucía (P11- CVI-7599)Ministerio de Economía, Industria y Competitividad (BES-2016-076579)Garantía Juvenil contract from Universidad de Sevill

    THE UNIVERSITY AS A COMMON POOL RESOURCE: a set of resources, moral and cultural values from the Academic Community of Universidad Politécnica Salesiana

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    This book contains information from Universidad Politecnica Salesiana’s Commons Research Group, created in 2016 to deepen as well as identify the implication and the possibilities of imagining the university as a “common pool resource” . This alternative must be explained because the connection of the use of commons – as explained by Elinor Ostrom in her book Governing the Commons. The evolution of institutions for Collective Action (2011) – with the possibility of reconsidering the university in all areas is not immediate nor casual and, at first, such connection seems odd in a time when we value belonging based on evidence accessible at first sight. In fact, what does a proposal which analyzes community and local government decision making methods regarding common resources have to do with university life? The aim of this preface is to answer this question and explain the connection that encourages and gives meaning to several contributions of this book. Each contribution deepens its derivations in the field of management, decision making and knowledge production
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