978 resultados para Storage stability
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Introducción: Las Lipofuscinosis Ceroideas Neuronales (LCNs) son un grupo de patologías neurodegenerativas hereditarias de atesoramiento lisosomal (PALs) caracterizadas por el almacenamiento en los lisosomas de materiales complejos pobremente reconocidos. Su curso es muy severo con desenlace fatal, habiendo sido definidos diversos tipos sobre la base del estudio de los fenotipos clínicos, enzimáticos, morfológicos y las mutaciones. Su incidencia es de 1:12.500 nacimientos vivos a nivel mundial. Las intervenciones farmacológicas con moléculas pequeñas han sido exitosas para algunas PALs; sin embargo, debido a que para cada una de las moléculas ha sido asumido un mecanismo de acción, la efectividad puede estar limitada a uno o a pocos desórdenes y no beneficiar a otros. Se han comprobado efectos diversos de una serie de moléculas tales como Miglustat, Chaperonas moleculares diseñadas, Clenbuterol, N-acetilcisteina (Mucomyst), Cisteamina, Gentamicina y PTC124. Los tratamientos farmacológicos/ con moléculas pequeñas podrían resultar exitosos para las LCNs, mereciendo consideración desarrollar terapias para estos desórdenesObjetivo generalo Investigar en un tipo de patologías del sistema nervioso central, las Lipofuscinosis Ceroideas Neuronales, el enfoque terapéutico-farmacológico con pequeñas moléculas aplicado a otras patologías hereditarias.Objetivos específicoso Desarrollar un prototipo de cultivo de fibroblastos de pacientes a nivel hospitalario en Córdoba y mantener cultivos de fibroblastos de pacientes afectados de una LCN de genotipo CLN2, con mutaciones conocidas. o Enriquecer los cultivos con fármacos/ moléculas pequeñas probadas en otras PALs.o Averiguar si se produce incremento de actividad enzimática de la Tripeptidil Peptidasa-I (TPP-I) lisosomal.Materiales y Métodos: cultivo de fibroblastos de pacientes con el agregado de fármacos/pequeñas moléculas. Los donantes serán diagnosticados en CEMECO a través de una estrategia sistematizada para el reconocimiento de las LCNs y se identificarán las mutaciones en el gen CLN2 causales de enfermedad. Se averiguará la actividad enzimática de TPP-I y se marcará la enzima con anticuerpos específicos en corridas electroforéticas por western blot. Resultados esperados: incrementos en la actividad enzimática de TPP-I en los cultivos celulares con agregado de fármacos/ pequeñas moléculas con respecto a los controles. Importancia del proyecto: se trata de una investigación traduccional (traslational research) en la cual la clínica y los servicios a pacientes se vinculan con la investigación científica, desde una perspectiva de integración. Se desarrolla en un Hospital Público, el Hospital de Niños de la Provincia de Córdoba, asiento del Centro de Estudio de las Metabolopatías Congénitas-CEMECO. Se beneficiarán los pacientes, dado que impactará sobre la calidad de los servicios hospitalarios al suministrar diagnósticos bajo los estándares internacionales, en estrecha vinculación con centros referenciales del exterior. Se obtendrán para los genes de las LCNs los datos del espectro de mutaciones y polimorfismos presentes en la región y se aportarán datos sobre posibilidades de las terapias farmacológicas en relación a cada una de las mutaciones.
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El hidrógeno tiene, actualmente, una atención considerable por su posible uso como combustible limpio y otros usos industriales y se ha demostrado que es posible hacer funcionar motores de combustión interna, por lo tanto es una alternativa viable respecto de fuentes de energía no renovables como el petróleo y tal vez sea en el futuro la tecnología más prometedora para reducir la contaminación, conservando el suministro de combustibles fósiles. Uno de los principales problemas para la utilización del hidrógeno como combustible es el del almacenamiento para que pueda ser seguro y transportable con todos los riesgos que esto supone. En este sentido el estudio de la adsorción de polímeros conductores (tal como polianilina, PANI o polipirrol PPy) y su posterior polimerización sobre hospedajes como aluminosilicatos meso y microporosos y carbones mesoporosos, es de suma importancia por sus propiedades para el almacenamiento de H2. El objetivo general de este proyecto es Investigar el almacenamiento de hidrógeno en nuevos composites nano/microestructurados. La síntesis de materiales micro/mesoporosos (MFI, MEL, BEA, L, MS41, SBA-15, SBA-1, SBA-3, SBA-16, CMK-3) para usos como hospedaje se realizan por sol-gel o síntesis hidrotérmica y se modificarán con TiO2, CeO2, ZrO2 y eventualmente con Ir, Ni, Zr. Muestras de estos hospedajes serán expuestos a vapores del monómero puro (anilina o pirrol). Luego se polimerizarán por polimerización oxidativa. Los nanocomposites sintetizados se caracterizarán por XRD, FTIR, DSC, TGA, SEM, TEM, EXFAS, XANES, UV-Vis. La adsorción de hidrógeno sobre los composites se llevará a cabo en un Reactor Parr, desde presiones atmosféricas y a altas presiones y varias temperaturas de adsorción . Los estudios de desorción de hidrogeno se llevarán a cabo en un equipo Chemisorb Micrometrics y se realizarán estudios termogravimétricos y de capacidad de retención de Hidrogeno por el nanocomposite. La importancia del estudio de este proceso tiene importantes implicancias económicas y sociales que serán preponderantes en el futuro debido a las cada vez más exigentes regulaciones ambientales. Además se contribuirá al avance del conocimiento científico, ya que es posible diseñar nuevos materiales, los que además permitirán generar reservorios de H2 con alta eficiencia. Por lo consiguiente: - Se desarrollarán nuevos materiales nanoestructurados, micro y mesoporosos y nanoclusters de especies activas en los hospedajes como así también la inclusión de polímeros (PANI, PPy) dentro de los canales de estos materiales. - Se caracterizarán estos materiales por métodos espectroscópicos (fisicoquímica de superficie). - Se estudiará la adsorción /absorcion de H2 en los nuevos materiales desarrollados. -Se aplicarán métodos de diseño de experimento (RDS), para optimizar el proceso de almacenamiento de H2, nivel de interacción de variables sinérgicas o colinérgicas.
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El objeto de estudio de este proyecto son los sistemas de calentamiento de agua mediante energía solar que funcionan termosifónicamente. En particular se tratará con dos diseños particulares generados por fabricantes de la Provincia de Córdoba y que han solicitado el asesoramiento del Grupo de Energía Solar (GES) para el mejoramiento de la performance térmica de dichos equipos. Se trata de dos sistemas que tienen materiales no tradicionales y se diferencian además por tener una distinta disposición del tanque de almacenamiento: uno es en forma vertical y el otro en forma horizontal. Basados en los resultados de un ensayo bajo norma internacional, donde se detectaron algunas puntos factibles de mejora, se propone en este proyecto el análisis en detalle de los equipos, para lo cual se les debe desarmar completos, para realizar un estudio analítico y experimental de los mismos con el objeto de hacer un planteo teórico-analítico del comportamiento de los mismos, con la implementación de propuestas de mejora y chequeo de los resultados. Se propone entonces como objetivo lograr un mejoramiento de la performance térmica de los citados equipos a partir de un estudio experimental y analítico. Asumiendo esta posibilidad de mejora, se plantea la hipótesis de que es posible representar el funcionamiento de estos equipos mediante modelos físico-matemáticos desarrollados a partir de ecuaciones y correlaciones conocidas y procesos a interpretar mediante resoluciones numéricas y softwares específicos de simulación. De esta manera, se plantea el despieze completo de los equipos para estudiar en detalle su estructura y conexiones internas y a partir de la geometría, dimensiones y propiedades termofísicas de materiales constructivos y fluidos de trabajo, realizar modelos físico-matemáticos que permitan realizar variaciones de propiedades y geometría y así buscar las mejores combinaciones que produzcan equipos más eficientes térmicamente. Los modelos físico-matemáticos serán codificados en lenguajes de alto nivel para poder luego de una validación de los modelos, correr simulaciones en un software de reconocimiento internacional que permite sumar dichos modelos mediante un protocolo de comunicación, haciendo que las poderosas prestaciones del software se puedan aplicar a nuestros modelos. Se complementará el estudio con un análisis exergético para identificar los puntos críticos en que se producen las pérdidas de oportunidad de aprovechar la energía disponible, para así analizar cómo solucionar los problemas en dichos puntos. Los materiales a utilizar serán los propios equipos provistos por los fabricantes, que serán modificados convenientemente para operarlos como prototipos Se espera obtener un conocimiento acabado de los procesos y principios de funcionamiento de los equipos, que permita plantear las mejoras, las cuales se implementarán en los prototipos, realizándose una medición mediante norma igual a la inicial para ver en que magnitud se logran las mejoras esperadas. Se pretende además que las mejoras a implementar, en la etapa de transferencia a las empresas involucradas, redunden no sólo en un beneficio técnico, sino que también los sea desde el punto de vista económico. Para ello se trabajará también sobre los procesos y métodos de fabricación para que los equipos mejorados no sean mas caros que los originales y de ser posible sean aún más económicos, todo esto apuntando a la difusión de la energía solar térmica y poner al alcance de todos estos equipos tan convenientes para la propagación de las energías limpias. El proyecto redundará también en un importante beneficio para el conocimiento de la comunidad científica en general, con el aporte de nuevos resultados en diseños novedosos y con nuevos materiales. Además, la institución se beneficiará con la formación que obtendrán los integrantes del proyecto, muchos de ellos en etapa de realización de sus estudios de posgrado y en una etapa importante de su vida como investigadores. The main goal of this project is the improvement of two thermosyphonic solar water heating systems, made of non conventional materials and with different arrangement of their storage tanks: one is vertical and the other one horizontal. The thermosyphonic systems are provided by manufacturers of the Córdoba Province, who came to the Solar Energy Group (GES) of the National University of Río Cuarto looking for help for the design of their products. In an agreement with these manufacturers, it was proposed this project in order to work analytically and experimentally in order to obtain physical-mathematical models of these two systems, which allow for changes to look by means of simulations the best changes to implement on the equipments for the improvement of their thermal performance. Then, the materials to be used are the proper systems provided by the manufacturers, which will be disarmed to be studied in detail. After the analytical study the proposals of improvement will be implemented in a high level language of programming to perform simulations in the environment of a well-known software for energy simulations (TRNSYS). After the simulations, the best modifications will be physically implemented in the prototypes to perform finally the same normalized test of the beginning and check the magnitude of the implemented improvements. The importance of this project is based on the offer of better systems the companies would make, which would benefit the deployment of the thermal solar energy. Another relevant point is to make the new equipments at the same cost of the previous ones or cheaper, in order to achieve a good deployment of the solar water heating systems; then, the manufacture processes and methods must be studied to obtain not only good technical solutions, but also economical equipments. In addition, this project will contribute to the increasing of the knowledge in the area of thermosyphonic solar systems and the training of postgraduate students.
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Ireland’s remote position on the tip of Europe ensures that the country is vulnerable to uncertainty of supply. The reliance on conventional sources of electricity has ensured that escalated prices and high carbon emissions have been witnessed whilst opportunities that inherent resources provide, such as the wind, have not been capitalised upon. The intermittent nature of the wind make it difficult to maximise its potential as in many cases the highest wind speeds are highest when demand is low. The West of Ireland’s combination of wind speeds and unique topography makes it suitable for and innovative wind powered pumped storage system, which can essentially regulate the wind generated electricity and integrate further penetration of renewable energy. In addition, its location along the Atlantic Ocean provides further scope for innovation as seawater can be integrated into the system design. The construction of such an unprecedented project in combination with increased interconnectors has the potential to make Ireland a rechargeable battery for Europe. However, such ambitious plans are at the very early stages and are in direct contrast to current events in the Irish energy market. This study focuses on the feasibility of West of Ireland pumped storage systems. Entailed within this is an extensive desk study, a detailed site selection process and a feasibility study of grid connection. To increase opportunities to identify the best possible site, the feasibility study was focused on the Galway and Mayo areas solely.
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The nutritional composition o f orange roughy (collected from the Northeast Atlantic near the Rockall Trough) was studied on a seasonal basis. In addition samples were aged and stability assessed. Protein levels (16.68-16.21% w/w) were found to be slightly higher than those recorded for the N ew Zealand species o f orange roughy and compared favourably with protein values for fish muscle in general. Statistically results show a significant seasonal variation with no variation from fish to fish or in the location within the fish. Lipid content (3.6-4.5% w/w) was found to be much lower than that recorded for New Zealand. As with protein statistically results show a significant seasonal variation and no variation from fish to fish or in the location within the fish. Moisture levels (77.3_79.6%w/w) compared favourably with values obtained from other studies. Again statistically results show a significant seasonal variation with no variation from fish to fish or within the fish. Iodine values (74.63-79.54) indicate the likely presence o f a high level o f mono unsaturated fatty acids. Statistically results show no significant seasonal variation and no sample variation or variation within fish. Thin layer chromatography o f the extracted fat showed the major type to be wax esters with a much lower amount o f triglycerides and smaller amounts of polar lipids, free sterols and free fatty acids. Total fatty acid composition was found to be very similar to that recorded from other studies and showed that most o f the oils extracted from the fish muscle contained a high percentage o f mono unsaturates namely 16:1,18:1, 20:1 and 22:1 (85.63 - 91.14% ) with 16:1 present in the smallest amounts and 18:1 the major one. The only saturated fatty M.Sc. in Biochemistry III Nutritional Composition, Quality and Spoilage Capacity of Specific Deep Sea Fish acids present in significant quantities were 14:0, 16:0 and 18:0, the total varied from a seasonal average high o f 4.05 % to an average low o f 2.27%. The polyunsaturated fatty acids linoleic and arachidonic acid were present in small quantities varying in total from 0.89% to 1.50%. Docosapentaenoic acid (D P A ) was found only in trace quantities in spring, autumn and winter samples and undetected in summer. Levels o f Eicosapentaenoic acid (EPA ) and Docosahexaenoic acid (D H A ) were also found in very low percentages and varied on a seasonal basis with average values ranging from 0.41% in summer to 1.03 % in autumn for EPA and from 1.44 % in summer to3.20 % in autumn for D H A . Again statistically results show a significant seasonal variation with no variation from fish to fish or location within the fish. Levels o f freshness were measured using the Thiobarbituric acid (T B A ), Total volatile base nitrogen (T V B -N ) and Trimethylamine (T M A ) techniques. The quality o f the fish upon arrival was excellent and well below legal/acceptable lim its.T V B -N values ranged from 6.88-8.91 mg/lOOg and T M A values from 4.82-6.46 mg/lOOg Values for T B A ranged from 0.18-0.35 mg Malonaldehyde/kg fish. The summer values were higher than the other seasons. Seasonal variation was significant for all methods with no variation from fish to fish or within the fish. Fish aged at +4°C in air did not exceed the T V B N lim it o f 35mg/100g until day 6 whereas the T V B N lim it was extended to 8 days for fish aged at +4°C in vacuum. However the T M A lim it o f 12mg/100g was reached on day 4 for fish stored at +4°C in air and on day 5 for vacuum packed samples stored at +4°C . Fish stored at -5°C in air and vacuum packed did not reach the T V B N lim it until day 61 but the T M A limit was reached on day 24 for fish stored at -5°C in air and was extended to 31 days for vacuum packed fish stored at-5°C. Prolonged storage at -18°C caused some deterioration o f the frozen fish muscle. Upon thawing the shelf life o f fish stored for 12 months was much shorter than that stored for 6 M.Sc. in Biochemistry IV Nutritional Composition, Quality and Spoilage Capacity of Specific Deep Sea Fish months. This in turn deteriorated faster than fresh fish held at refridgeration temperature in air. Orange roughy were found to be a good source of protein with moisture levels similar to that o f other fish. They were o f medium fat content but have a very poor content o f the essential omega 3 and omega 6 fatty acids. Orange roughy can be stored at -18°C but its subsequent refridgerated shelf life will be shorter than that o f unfrozen orange roughy stored at refridgeration temperature. Orange roughy are a very important part o f the ecosystem. Their composition is less nutritionally beneficial than more readily available fish for human consumption and therefore should not be fished at all
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Scheduling, job shop, uncertainty, mixed (disjunctive) graph, stability analysis
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Otto-von-Guericke-Universität Magdeburg, Fakultät für Mathematik, Univ., Dissertation, 2015
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The effects of hydrological disturbances by flooding and drought on the diversity and stability in a temporary river fish community in the Brazilian semiarid region were analyzed over the 1996 hydrological cycle. Twelve collections of fishes were made during the wet and dry phases, and 789 individuals of 16 species were collected. Diversity was measured using Simpson's Index (S) and community stability was analyzed by the variation in abundance using Kendall's W concordance test. Fish diversity in the Taperoá river was subjected to hydrological disturbances by flooding and drought. During the wet phase the diversity was higher (S = 0.855) than during the dry phase (S = 0.771). The community was considered stable during the whole annual hydrological cycle (W = 0.418 p < 0.001), but a higher stability in the community was found during the dry phase. During the dry phase the number of dominant species was smaller than during the wet phase.
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We are interested in coupled microscopic/macroscopic models describing the evolution of particles dispersed in a fluid. The system consists in a Vlasov-Fokker-Planck equation to describe the microscopic motion of the particles coupled to the Euler equations for a compressible fluid. We investigate dissipative quantities, equilibria and their stability properties and the role of external forces. We also study some asymptotic problems, their equilibria and stability and the derivation of macroscopic two-phase models.
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This paper aims to account for varying economic performances and political stability under dictatorship. We argue that economic welfare and social order are the contemporary relevant factors of political regimes' stability. Societies with low natural level of social order tend to tolerate predatory behavior from dictators in exchange of a provision of civil peace. The fear of anarchy may explain why populations are locked in the worst dictatorships. In contrast, in societies enjoying a relative natural civil peace, dictatorship is less likely to be predatory because low economic welfare may destabilize it.
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We study two-sided matching markets with couples and show that for a natural preference domain for couples, the domain of weakly responsive preferences, stable outcomes can always be reached by means of decentralized decision making. Starting from an arbitrary matching, we construct a path of matchings obtained from `satisfying' blocking coalitions that yields a stable matching. Hence, we establish a generalization of Roth and Vande Vate's (1990) result on path convergence to stability for decentralized singles markets. Furthermore, we show that when stable matchings exist, but preferences are not weakly responsive, for some initial matchings there may not exist any path obtained from `satisfying' blocking coalitions that yields a stable matching.
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We study the incentives of candidates to enter or to exit elections in order to strategically affect the outcome of a voting correspondence. We extend the results of Dutta, Jackson and Le Breton (2000), who only considered single-valued voting procedures by admitting that the outcomes of voting may consist of sets of candidates. We show that, if candidates form their preferences over sets according to Expected Utility Theory and Bayesian updating, every unanimous and non dictatorial voting correspondence violates candidate stability. When candidates are restricted to use even chance prior distributions, only dictatorial or bidictatorial rules are unanimous and candidate stable. We also analyze the implications of using other extension criteria to define candidate stability that open the door to positive results.
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Qin [J. Eco. Th., 1996] recently showed that in a game of endogenous formation of cooperation structure, if the underlying TU-game is superadditive, then the full cooperation structure is stable. In this note, we characterize the class of games that ensure the stability of the full cooperation structure, and show that this class is much larger than that of superadditive TU-games.
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Consider a Riemannian manifold equipped with an infinitesimal isometry. For this setup, a unified treatment is provided, solely in the language of Riemannian geometry, of techniques in reduction, linearization, and stability of relative equilibria. In particular, for mechanical control systems, an explicit characterization is given for the manner in which reduction by an infinitesimal isometry, and linearization along a controlled trajectory "commute." As part of the development, relationships are derived between the Jacobi equation of geodesic variation and concepts from reduction theory, such as the curvature of the mechanical connection and the effective potential. As an application of our techniques, fiber and base stability of relative equilibria are studied. The paper also serves as a tutorial of Riemannian geometric methods applicable in the intersection of mechanics and control theory.
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This paper is devoted to the analysis of all constitutions equipped with electoral systems involving two step procedures. First, one candidate is elected in every jurisdiction by the electors in that jurisdiction, according to some aggregation procedure. Second, another aggregation procedure collects the names of the jurisdictional winners in order to designate the final winner. It appears that whenever individuals are allowed to change jurisdiction when casting their ballot, they are able to manipulate the result of the election except in very few cases. When imposing a paretian condition on every jurisdictions voting rule, it is shown that, in the case of any finite number of candidates, any two steps voting rule that is not manipulable by movement of the electors necessarily gives to every voter the power of overruling the unanimity on its own. A characterization of the set of these rules is next provided in the case of two candidates.