382 research outputs found
Estudio técnico-económico de una planta desaladora de agua de mar por ósmosis inversa
En el següent escrit: Estudi técnic-económic d’una planta desaladora d’aigua de mar per osmosis inversa, es pretén donar al lector una idea del procés d’Osmosis Inversa; el qual, ja el podríem ubicar dins dels processos de separació per membranes.
Es pretén que aquesta idea sigui el més pràctica possible, sense deixar de banda els aspectes teòrics corresponents, però descartant aquells que, encara tenir relativa importància, l’únic que se aconseguiria amb el seu estudi, seria ampliar el contingut de l’anomenat projecte sense aportarnos això cap benefici relacionat amb l’essència del tema, com es la desalació d’aigua de mar per osmosis inversa.
Es per aquest motiu que l’estudi que segueix, es divideix en cinc volums.
El primer recull tots els aspectes teórico-práctics, on el lector pot trobar els diferents processos de separació per membranes, les consideracions sobre l’aigua i tot el relacionat amb el fonament fisico-químic que ens pertoca, o sia, la ósmosis inversa: definicions, conceptes bàsics, procés, membranes, etc. L’aspecte pràctic al que ens referim ve reflexat en petits sub-apartats, tals com: neteja eficaç de les membranes, o en seccions posteriors, en petits apartats on es donen recomanacions pràctiques, de instal•lació i inclòs de fabricació d’aparells per postratament.
El volum segon és una descripció detalla de l’instal•lació, on s’estudia des de la presa d’aigua de mar fins l’obtenció d’aigua producte, nomenant-se tots els equips, vàlvules, bombes, filtres, etc., que l’aigua travessa en el seu procés.
Els tres volums restants corresponen al aspecte més tècnic, on es mostren, por ordre: càlculs, plànols i pressupost o memòria econòmica
Mechanical analysis of Genoa 03 stirling engine
Due to the new technologies development based on renewable sources of energy, in recent years Stirling engines have become very important in the energetic sector. Many of them do not allow the use of fluid lubricants and, thus, the effect of friction losses is important. For this purpose, a mathematical model has been developed based on the force balance in the crankshaft using the pressure distribution in the cylinders. The aim of this work is to characterize the mechanical losses in a Genoa 03 Stirling engine using a numerical model and experimentally via the drag method. The results of this model have been compared with those obtained experimentally on Genoa 03 Stirling engine. In the experimental results, a proportional increase in friction torque due to the average pressure and the speed of the crankshaft is observed. The first of these is caused by an increase of dry friction forces and the second, by the viscous friction between the working fluid and the inner walls of the engine. Also in this paper, irreversible processes in a beta type Stirling engine have been investigated in order to highlight the impact of losses on mechanical power and its performance. This article develops the first study of the mechanical losses of Genoa 03 experimental Stirling engine, which has an output power of 3 kW. Although the model response follows the same trends as the experiments, those simplifications provide errors which become more significant as the engine speed increases.Ministerio de Economía y Competitividad ENE2013-43465-
Responsabilidad del Estado colombiano sobre los perjuicios ocasionados a la salud de las personas por el deterioro de la calidad del aire de Medellín
El presente trabajo tiene como finalidad determinar la responsabilidad del Área Metropolitana del Valle de Aburrá y del Municipio de Medellín sobre las afectaciones y perjuicios que se generan en la población a causa de la mala calidad del aire en la ciudad de Medellín. Para esto se analizarán las diferentes normas y fallos jurisprudenciales de las altas cortes de Colombia, mediante la cual se les han otorgado a las entidades antes mencionadas las obligaciones y deberes sobre la preservación del medio ambiente y por ende de la buena calidad del aire. Asimismo se estudiaran los elementos para determinar la responsabilidad del Estado y así determinar la responsabilidad del Área Metropolitana y el Municipio de Medellín. Por ultimo se realizará un análisis a un estudio demográfico hecho y para así determinar cuál es la percepción de los habitantes de la ciudad de
Medellín respecto de la problemática de la mala calidad del aire en la ciudad.The purpose of this thesis is to determine the responsibility of the Metropolitan Area of Valle de Aburrá and the Municipality of Medellín for the damages that are generated in the population due to poor air quality in the city of Medellín. For this, the different norms and jurisprudential rulings of the Colombian high courts will be analyzed
Estudio técnico-económico de una planta desaladora de agua de mar por ósmosis inversa
En el següent escrit: Estudi técnic-económic d’una planta desaladora d’aigua de mar per osmosis inversa, es pretén donar al lector una idea del procés d’Osmosis Inversa; el qual, ja el podríem ubicar dins dels processos de separació per membranes.
Es pretén que aquesta idea sigui el més pràctica possible, sense deixar de banda els aspectes teòrics corresponents, però descartant aquells que, encara tenir relativa importància, l’únic que se aconseguiria amb el seu estudi, seria ampliar el contingut de l’anomenat projecte sense aportarnos això cap benefici relacionat amb l’essència del tema, com es la desalació d’aigua de mar per osmosis inversa.
Es per aquest motiu que l’estudi que segueix, es divideix en cinc volums.
El primer recull tots els aspectes teórico-práctics, on el lector pot trobar els diferents processos de separació per membranes, les consideracions sobre l’aigua i tot el relacionat amb el fonament fisico-químic que ens pertoca, o sia, la ósmosis inversa: definicions, conceptes bàsics, procés, membranes, etc. L’aspecte pràctic al que ens referim ve reflexat en petits sub-apartats, tals com: neteja eficaç de les membranes, o en seccions posteriors, en petits apartats on es donen recomanacions pràctiques, de instal•lació i inclòs de fabricació d’aparells per postratament.
El volum segon és una descripció detalla de l’instal•lació, on s’estudia des de la presa d’aigua de mar fins l’obtenció d’aigua producte, nomenant-se tots els equips, vàlvules, bombes, filtres, etc., que l’aigua travessa en el seu procés.
Els tres volums restants corresponen al aspecte més tècnic, on es mostren, por ordre: càlculs, plànols i pressupost o memòria econòmica
Influence of Different Vinification Techniques on Volatile Compounds and the Aromatic Profile of Palomino Fino Wines
The aim of this study was to evaluate the influence of vinification techniques on volatile compounds and sensory profiles in young Palomino fino white wines. Four winemaking techniques (pellicular maceration, supra-extraction and use of commercial yeast strains and of beta-glycosidase enzymes) were implemented to enhance the aromatic quality of wines elaborated from this neutral variety of grape. Volatile compound content, aromatic profile (OAVs) and sensorial analysis were determined. The results showed that all the vinification techniques studied led to an increase in volatile compounds compared to the control wine. Likewise, an influence of the vineyard and must extraction method on these compounds was observed. However, the greatest changes in aroma activity and sensory profile were a result of the pellicular maceration and supra-extraction techniques. The latter was differentiated by the highest content of terpenes and, consequently, the highest odour activity values of floral series. In addition, the supra-extraction was a very selective technique since it extracted terpenes and aromatic precursors, but not the acids responsible for the fatty characteristic, such as octanoic acid. In terms of sensory profile, the supra-extraction technique improved the intensity of the Palomino fino white wine and its aromatic quality with a previously not-determined floral character
Ion Beam Experiments to Emulate Nuclear Fusion Environment on Structural Materials at CMAM
One of the major problems not only in nuclear fusion but in all the fields that have to face irradiation damage is to predict the microstructural evolution of all the features that are involved in the good response of the material. In the case of nuclear fusion, it is well known that structural materials that will be a fundamental piece in the future reactor must withstand severe neutron irradiation damage, high temperatures, and cyclic stresses which will result in a reduction of the lifetime of the component. For that reason, a big effort is being done for the scientific community in order to understand the complex mechanisms that lie in the relationship between irradiation damage, microstructure, temperature, stresses, etc. However, neutron irradiation brings inherently transmutation and nuclear activation, which makes extremely hard to study those samples. Therefore, the scientific community is using since long time ago ion beam facilities to emulate the neutron damage, without the worst inconvenience. In this chapter, the authors described briefly the facility located at Centro de MicroAnálisis de Materiales (CMAM), Madrid, and presented afterward some examples of experiments that Spanish Nuclear Fusion Laboratory at CIEMAT has been carrying out related to this matter
Frequency response of Valencia oranges to selective harvesting by vibration
Citrus mechanical harvesting has been investigated since the 1960’s. Even though mechanical harvesting could significantly lower production costs, the implementation by the private sector has been slow. The current harvesting technologies detach the fruits with trunk, canopy or branch vibration. For late-season sweet orange varieties which simultaneously bear mature fruit, immature fruitlets and flowers shaker harvesting decreases the subsequent year’s yield. This study, investigated the frequency response of mature fruits and immature fruitlets to determine the optimum frequency range for an efficient and selective harvest. Laboratory vibration transmission tests were conducted with 14 branches bearing 76 mature fruits and 151 immature ‘Valencia’ fruitlets. The fruit and branch response to the forced vibration was measured by several sets of five triaxial accelerometers with a dynamic signal analyser. Three frequency ranges with the highest vibration transmission values were identified for mechanical harvesting lower than 10 Hz. The first frequency range (1.5-2.5 Hz) corresponded best with the most efficient vibration transmission, involving more than 90% of fruit. The second frequency range (4.5-5 Hz) successfully discriminated between mature fruit and immature fruitlets. In this frequency range, 53.4% of mature fruit amplified the acceleration a mean value of 2.2 times, while only 7.3% of immature fruitlets amplified the acceleration with a mean value of 4.4 times. The lowest third frequency range had a vibration transmission value of 7-8 Hz. The frequency response of mature citrus fruits, and their markedly higher fruit mass, were significant factors in efficient selective mechanical harvesting
Confectio Gari Pompeiani. Experimental procedure for the preparation of Roman fish sauces
El presente trabajo hace públicos por primera vez los resultados de un proceso experimental fruto de la colaboración entre las universidades de Cádiz y Sevilla. Dicho proceso, en el que han participado arqueólogos y bioquímicos, se ha realizado en el Departamento de Ingeniería Química de la Facultad de Ciencias de la Universidad de Cádiz y ha consistido en la identificación de la naturaleza concreta y en la reproducción física de la afamada salsa salada de pescado greco-romana denominada garum (liquamen), de un subproducto alimenticio sólido de esta (hallec) y de una salsa secundaria y de menor calidad denominada en latín muria. El estudio filológico de antiguas recetas de confección del garum (confectio gari) y los resultados analíticos de los residuos de estos productos recogidos durante la excavación de la denominada bottega o tienda del garum de Pompeya han permitido simular su producción artesanal en laboratorio y obtener unos condimentos salados cuyo aspecto físico y características alimentarias coinciden con los descritos por las fuentes literarias grecorromanas y con los que aún muestran los residuos orgánicos analizados de estas producciones.The present work publishes for the first time the results of an experimental process carried out in cooperation between the Universities of Cádiz and Seville. This process, involving the participation of archaeologists and experts in biochemistry, has been effected in the chemical engineering department of the University of Cádiz and has focused on the characterization and reproduction of the famous Graeco- Roman salted fish sauce known as garum (liquamen), of a solid by-product of this sauce (hallec) and of a secondary, lesser quality, sauce known in Latin as muria. The philological analysis of ancient recipes (confectio gari) and the analysis of the residues collected in the so-called bottega or Garum Shop, in Pompeii, have permitted their artisanal reproduction in the laboratory. The physical aspect and alimentary features of these products coincide with those described in the ancient sources and with the organic residues under analysis.España. Ministerio de Economía y Competitividad 15733España. Ministerio de Economía y Competitividad HAR2011- 28244España. Ministerio de Economía y Competitividad HAR2013-43599Fondo Europeo de Desarrollo Regional (FEDER) 15733Fondo Europeo de Desarrollo Regional (FEDER) HAR2011- 28244Fondo Europeo de Desarrollo Regional (FEDER) HAR2013-43599Instituto del Patrimonio Cultural de Españ
Descripción del contexto social y familiar de un grupo de jóvenes adeptos al metal extremo en Medellín
RESUMEN: La pertenencia a una subcultura urbana dada gracias a la preferencia por un gusto musical específico, puede generar efectos relevantes en la construcción de identidad y rol que cumplen las personas, el interés por conocer las experiencias y contextos que rodean a los jóvenes de la ciudad de Medellín ha sido un tema de intereses en diferentes campos de acción políticos, educativos y sociales. Partiendo de ello, la presente investigación busca aportar a la descripción de algunos aspectos relacionales y personales de un grupo de jóvenes de Medellín adeptos al subgénero musical metal extremo, mediante entrevistas en las cuales se busca la expresión de sus experiencias y con la sistematización de estos datos para describir con detalle la semejanza, diferencias y particularidad de su contexto.ABSTRACT: The beloging to urban subculture given thanks to the preference for a specific musical taste can generate relevant effects in the construction of identity and role played by the people, the interest to know the experiences and contexts that surround the young people of the city of Medellín has been a topic of interest in different political, educational and social fields of action. Based on this, the present research seeks to contribute to the description of some relational and personal aspects of a group of young people of Medellín adept to the subgenre musical extreme metal, through interviews in which the expression of their experiences is sought and with the systematization of these Data to describe in detail the similarity, differences and particularity of their context
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