University of Castilla-La Mancha
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Ser historiador del arte
Get PDFEste artículo está firmado por cuatro historiadores del arte que proporcionan un punto de vista conjunto formado por las experiencias y reflexiones que han vivido, tanto en común como por separado, con el fin de ofrecer al lector una visión general sobre la profesión del historiador del arte.This article is signed by four art historians who provide a joint point of view formed by the experiences and reflections they have lived, both together and separately, in order to offer the reader an overview of the profession of art historian
Electroremediation of a natural soil polluted with phenanthrene in a pilot plant
Get PDFIn this work, a pilot plant with two rows of three electrodes in semipermeable electrolyte wells was used to study the electrokinetic treatment of a natural soil polluted with phenanthrene (PHE). The electrokinetic pilot plant was an open system, i.e., there was direct contact between the soil and air. To increase the solubility of phenanthrene, thereby enhancing its transport through the soil, an aqueous solution of the anionic surfactant dodecyl sulfate was used as a flushing fluid. The results show that at the pilot scale considered, gravity and evaporation fluxes are more relevant than electrokinetic fluxes. Contrary to observations at the laboratory scale, desorption of PHE promoted by electric heating appears to be a significant removal mechanism at the pilot scale. In addition, PHE is dragged by the electroosmotic flow in the cathodic wells and by electrophoresis after interaction of the surfactant with phenanthrene in the anodic wells. In spite of the long treatment time (corresponding to an energy consumption over 500 kWh m−3), the average removal attained was only 25%
Knowledge-city index construction: An intellectual capital perspective
No full textKnowledge cities are the most capable of producing sustainable economic growth. Cities, where relationships between people are more extensive, provide the most natural environment in which to look for evidence of the knowledge spillovers so emphasized by the endogenous growth theory
La Guerra de Sucesión y su impacto en las relaciones anglo-españolas en la América de finales del XVIII
No full textLa Guerra de Sucesión Española, que enfrentó a los Borbones y los Habsburgo por el trono de España, tuvo repercusiones significativas en las colonias americanas. El conflicto no solo alteró las dinámicas políticas y económicas en Europa, sino que también influyó en las relaciones coloniales. En América, las tensiones entre las colonias inglesas y españolas se intensificaron, afectando el comercio y la política local. La guerra llevó a una serie de tratados y acuerdos que redefinieron las fronteras y las esferas de influencia en el continente americano, consolidando el poder británico en ciertas áreas y debilitando la presencia española
Valorization of polystyrene wastes using natural terpenes and high pressure CO2.
Get PDFLarger and increasing volumes of plastics are produced yearly due to their low price, versatility and suitability for a large number of applications and uses. Unfortunately, after its use, polymers become a valuable feedstock and they must be recovered in order to prevent the environmental pollution and to preserve natural sources following the mandates of the European policies about wastes management. In fact, during the last decade, some positive trends concerning the recovery and recycling of polymers are occurring. The recycling of plastic wastes is justified enough on environmentally basis, but also is demonstrated that presents a large potential from an economical point reducing the pressure on the original sources of raw materials. The use of plastic wastes as source of high-added value products impulse the recycling alternative being a great environmental opportunity by several reasons: the reduction of the pressure on the exploitation of raw materials, resources and energy consumption, the increase of free volume in landfills, and obviously, the associated benefits (employment and lower prices).
This research work is focused on the recycling of Polystyrene (PS) wastes by an environmentally friendly technology for the production of high-added value products. The mentioned polymer constituted and important issue since it is not biodegradable, massive amounts of energy and resource are consumed during its production, is very versatile. As it is used in daily life application with very low lifespan, it makes that frequently finish in landfills or in small pieces in seas and oceans.
In order to promote the recycling of Polystyrene wastes, new processes should be designed to reduce the environmental impacts and costs and to improve the quality of the recovered products regarding to the traditional recycling techniques (mechanical recycling, chemical recycling or energy recovery). Thus, a technology according to the Green Chemistry principles is proposed. The new recycling process for Polystyrene wastes consists on the dissolution of the polymer in natural terpene solvents to reduce its volume (decreasing transport costs), remove contaminants, dissolve specifically the polymer from mixed plastic waste streams, avoiding its degradation. Next, the separation of the terpenes from the solutions is performed by the addition of high pressure CO2 as antisolvent which makes that the polymer precipitates while the solvent is removed. Carbon dioxide (CO2) has been the choice antisolvent because it is able to solubilise terpenes easily and thank to its sorption in the polymer, the processing is enhanced. Furthermore, CO2 has resulted to be a very promising blowing agent which encourages its use for the production of microcellular foams, a high-added value product. Moreover, it should be highlighted that any waste stream from the process is obtained because the terpenes and the CO2 are easily recovered and reused in several cycles of the process, minimizing the environmental impact.
As the objective is to create new products with higher added value than the original raw material using a residue, is necessary to know the interaction between Polystyrene, terpene solvents and high pressure CO2 to anticipate the conditions in which the removal of the solvent has to be done to produce improved new materials. The research started up with the definition of the binary systems which makes the different steps of the process. Thus, in order to determine the maximum amount of treated wastes with a certain amount of solvent, the influence of the temperature, the molecular weight and the source of the Polystyrene wastes (Expanded or Extruded) on the solubility in terpenes was studied. It was concluded that terpenes are suitable solvents for the dissolution of the polymer at room temperature independently of its molecular weight and processing. On the other hand, the solubility of terpenes in CO2 is crucial since the success of the separation process depends on it. It was observed that terpenes are fully soluble in CO2 at room temperature and mild pressure. Finally, although Polystyrene is insoluble in CO2, the gas is greatly absorbed into the polymer causing its swelling and plasticization. This phenomenon entails a modification of the Polystyrene properties (viscosity, interfacial tension and glass transition temperature), which affects the processing of the polymer at high pressure.
Once the binary systems had been defined and studied, it is important to know the behaviour of the ternary mixtures involved in the process (CO2/terpenes/Polystyrene) since the knowledge of the binary systems is not enough to select the operating conditions successfully. According to the binary system, the solvent removal is possible thanks to supercritical CO2 since it provides high solubility of terpenes and fully PS insolubility at moderated pressures and temperature. The influence of pressure, temperature and concentration on the solubility of the selected terpenes (Limonene and p-Cymene) in CO2 and on the sorption of CO2 into the solutions (Polystyrene/Limonene and Polystyrene/p-Cymene) were determined. From these results, the most suitable conditions for the precipitation of Polystyrene using CO2 as antisolvent were those where the antisolvent density was higher (high pressure and low temperature) and the concentration of Polystyrene in the solutions moderated.
Next, the properties of the mixtures were determined since the knowledge of the phases equilibrium is too poor to define the global process. The plasticizing effect of CO2 on the polymer is also observed in terpene solutions and consequently, a deep understanding of how the properties of materials and the processing parameters affect the behaviour of the mixtures is required. The study of the viscosity, interfacial tension and glass transition temperature of the mixtures was carried out. Although the viscosity and the interfacial tension of the ternary systems were significantly affected by the antisolvent, the glass transition temperature showed similar results to those obtained for the binary system Polystyrene/CO2.
Once the system was characterized and the equilibrium and properties of the ternary mixtures determined, the recycling process was studied. Two main alternatives were explored: continuous or discontinuous regime. In continuous regime, named Supercritical Antisolvent (SAS) the polymer solution is sprayed to a vessel previously filled with CO2. This process allows the control over the particle size. Nevertheless, Polystyrene is precipitated according to a wide variety of morphologies and the knowledge of the hydrodynamic of the system was crucial to understand the process. Thus, the way in which the polymer solution is contacted with CO2 affects the diffusion and mixing of the fluids and consequently the way on which the polymer precipitates. Due to the technical difficulties found along the development of the SAS process, the discontinuous one was proposed as alternative, which is focused on the foaming of the solution for the production of Polystyrene microcellular foams. In this case, CO2 behaves not only as solvent of the terpene and antisolvent of the Polystyrene, but also as blowing agent of the polymer, which allows tuning the cells size, cells size distribution and cells density of the foamed Polystyrene. The presence of the terpene promotes the mass transfer that is mainly governed by the diffusion of the CO2 into the polymeric rich phase due to the relaxation of the polymer chains. The recycled Polystyrene, obtained following this methodology, presents microcellular structure, non remarkable traces of terpene and any evidence of degradation.
Finally, the economic analysis of the process was carried out to determine the feasibility of the recycling process. The traditional high costs involved in the recycling of PS wastes are balanced by the high added value of the recycled polymer, but also due to the mild operating conditions required to carry out the process. The selective dissolution technique eliminates the need to sort previously the polymer from mixed plastic waste streams. The economical benefits, together with the environmental advantages show the interest of the process for the treatment of the large amount of Polystyrene wastes produced daily
María Isabel del Val Valdivieso (coord.), Monasterios y recursos hídricos en la Edad Media, Madrid, Asociación Cultural Almudayna, 2013. 163 pp. ISBN: 978-84-87090-68-4 [reseña]
Get PDFMetodología de evaluación de competencias transversales a nivel titulación en el Grado de Ingeniería Forestal y del Medio Natural (ETSIAM de Albacete)
No full textThe educational planning and the control in the acquisition of transversal skills at Faculty level are one of the main axes in which educational changes are more necessary. The main objective was to implement a coordinated way assessment tools (rubrics and training activities) to evaluate general skills in the Forest Engineering. Methods: We have developed an evaluation methodology based on groups of teachers. Each group controlled and analyzed the evaluation of each competency by applying a rubric. The members of each group belong to different subjects and courses. It was not necessary to assess all the skills in one subject and this was progressively evaluated in different courses. Results: The rubric was created as a matrix of assessment criteria. Each criterion is scored with 5 levels of performance. In addition, we built an online tool, called SharePoint, to share rubrics and review training activities. Conclusions: The proposed methodology permitted us to control the process of implement the competency-based learning, and helps to the teaching staff to assess competencies included in this Forestry Degree. The developed rubrics standardized and improved the evaluation method, and at the same time they improved the process of training and acquisition of skills by studentsAntecedentes e introducción: La planificación docente a nivel titulación y el control en la adquisición de competencias transversales es uno de los ejes en el que deben seguir realizándose cambios. El principal objetivo fue implantar coordinadamente herramientas de evaluación (actividades y rúbricas) para las competencias generales del Grado en Ingeniería Forestal y del Medio Natural. Método: La metodología de evaluación está basada en la formación de grupos de trabajo (profesores). Cada grupo controló la evaluación de cada competencia aplicando una rúbrica. Los miembros de cada grupo pertenecen a diferentes materias y cursos. No fue necesario aplicar todas las competencias en una asignatura, y éstas se fueron evaluando progresivamente en diferentes cursos. Resultados: La rúbrica fue creada como una matriz de criterios de evaluación. Cada criterio es puntuado con 5 niveles de desempeño. Además, se ha creado un Espacio Virtual, SharePoint, para compartir rúbricas y revisar las actividades de evaluación. Conclusiones: La metodología propuesta ayuda a los docentes a evaluar las competencias incluidas en el Grado Forestal. Las rúbricas desarrolladas estandarizaron y mejoraron el método de evaluación, al tiempo que favorecieron el proceso de formación y la adquisición de competencias por los estudiantes
Employment opportunities in Spain: Gender differences by education and ICT usage
Get PDFEducation is a main determinant of employment, but not in isolation. Informationand Communication Technologies (ICT) skills have become a key element to facilitate employment opportunities. The growth in female educational attainment and ICT use is closing the gender divide and favouring female employment. We present evidence on this for the Spanish labour market using: a) a dynamic labour demand function; and b)analyzing the main factors explaining probabilities of finding a job based on traditional characteristics that affect employability and others related to ICT use. We develop this analysis for total population and distinguishing men and women using a Heckman model
La protección penal de la seguridad vial
Get PDFEn esta tesis se pretende analizar si la seguridad vial, y en concreto la conducción con exceso de velocidad, merece protección penal o por el contrario basta con la ofrecida por el Derecho administrativo.
Contenido:
El trabajo está dividido en siete capítulos además de una introducción y unas conclusiones finales. La introducción contiene la explicación del contenido y estructura de todo el trabajo, y con ella es suficiente para conocer qué encontraremos a lo largo de todos los capítulos.
En el Capítulo I se analiza el concepto de seguridad vial, la distribución de la competencia sobre la misma y un estudio de Derecho comparado sobre los Estados de nuestro entorno y otros ajenos al mismo.
El Capítulo II contiene un estudio de la legislación administrativa y penal de la seguridad vial en el Derecho español desde 1897 hasta nuestros días.
El Capítulo III tercero está dedicado al estudio del bien jurídico seguridad vial, lo más destacado del mismo es la justificación de su protección penal como bien jurídico instrumental del derecho fundamental a la libre circulación por el territorio nacional, desvinculándolo del bien jurídico vida o integridad física de las personas.
En el Capítulo IV se estudia el origen del peligro que significa la circulación de los vehículos a motor, fundamentándolo en la energía cinética que estos desarrollan al circular y no sólo en la velocidad a la que lo hacen. Se busca una velocidad a partir de la cual el peligro cambie cualitativa o cuantitativamente, para justificar el cambio de la protección administrativa a la penal, y para ello se analizan los diferentes modelos teóricos con los que se gestiona en la actualidad la circulación de vehículos a motor.
El Capítulo V está dedicado al análisis del tipo objetivo y subjetivo de la conducción exceso de velocidad (art. 379.1). Contiene un ordinograma que pone en relación las diferentes posibilidades de concurso entre la conducción con exceso de velocidad y la producción de accidentes, lesiones, conducción temeraria o con manifiesto desprecio a la visa, y la relación de las diferentes situaciones producidas con los diferentes bienes jurídicos que intervienen en los hechos.
La actividad procesal está analizada en el Capítulo VI, en ella es de destacar el análisis de los errores máximos permitidos en los cinemómetros y en los velocímetros, así mismo es novedoso la interpretación del tipo subjetivo del tipo de conducción con exceso de velocidad, que podría posibilitar a los jueces y tribunales no interpretar como velocidad reglamentaria las velocidades máximas específicas€ de circulación.
El Capítulo VII está dedicado a unos análisis estadísticos, en los que se analizan las relaciones entre la mortalidad general es España y la producida por causas ajenas a las enfermedades y en concreto las debidas a suicidios, ahogamientos y accidentes de tráfico. En otro apartado se analizan el número de delitos cometidos por conducción con exceso de velocidad en relación con la longitud de las diferentes vías de circulación y con el número de vehículos totales que circulan por ellas; también se relacionan con el número de denuncias interpuestas por la Agrupación de Tráfico de la Guardia Civil y con el número de detenidos o imputados por la citada Agrupación. El último análisis está dedicado al estudio comparativo del delincuente contra la seguridad vial y el delincuente en general.
Conclusión:
Como conclusión general se expone que la seguridad vial y en concreto la conducción con exceso de velocidad no necesita protección penal, bastando con la ofrecida por el Derecho administrativo. Se ofrece una propuesta de lege ferenda sobre el artículo 379.1, destacando la cuarta propuesta en la que se introducen factores para hacer el tipo proporciona mediante unas tablas que corrigen los excesos previstos por el tipo de 60 y 80 km/h.
En general la tesis ofrece un estudio novedoso sobre la seguridad vial, en la que no priman los factores dogmáticos, por el contrario se incide en los aspectos científicos-técnicos de la misma, sin que ello implique un alejamiento del Derecho como disciplina en la que está inserta la seguridad vial
Solvent-free Microwave Assisted Synthesis of New 2,4-Dimethoxybenzylaminotriazines
Get PDFAn efficient and green synthesis of 2,4-dimethoxybenzyaminotriazines is described, by reaction of disubstituted triazines with 2,4-dimethoxybenzylamine under microwave irradiation and in solvent-free conditions. NMR spectroscopy has been used to determine the free energy of activation of the restricted rotation of the ArylN-triazine bond that is a slow process at room temperature. Contrarily, the benzylN-triazine bond shows a rapid rotation at room temperature