Buscador

Encontrado(s) 2241961 resultado(s)
Encontrada(s) 224197 página(s)

Estructura fina de poliéster de diferente uso final, Fine structure of polyester fibres with different end uses, Structure fine de fibres de polyester destinées à divers usages

  • Gacén Guillén, Joaquín
  • Cayuela Marín, Diana
  • Tzvetkova, Milena
  • Manich i Bou, Albert Mª
Cinco fibras de poliéster PET para textiles de diferentes usos finales y fabricadas por una misma productora han sido caracterizadas determinando su peso molecular, cristalinidad por calorimetría diferencial, solubilidad diferencial y sorción de yodo. Estas técnicas de caracterización se han aplicado también a un hilo continuo convencional, a otro teñible con colorantes catiónicos, ambos fabricados por la misma compañía, y a un hilo industrial cord., Five PET polyester fibres for textiles with different end uses produced by the same manufacturer were characterized by determining their molecular weight, their degree of crystallinity using differential calorimetry, differential solubility and iodine sorption. These characterization techniques were also applied to a conventional continuous yarn, to another which can be dyed using cationic dyes (both of which were produced by the same company) and to an industrial cord., Cinq fibres de polyester PET pour des textiles destinés à divers usages, fabriquées par le même producteur, ont été caractérisées en déterminant leur poids moléculaire, la cristallinité par calorimétrie différentielle, la solubilité différentielle et la sorption d’iode. Ces techniques de caractérisation ont été également appliquées à un fil continu conventionnel, à un autre admettant la teinture avec des colorants cationiques, tous deux fabriqués par la même entreprise, et à un fil industriel cord.
Proyecto:


Predicción de avenidas mediante la teoría de los subconjuntos borrosos

  • Soto, Gabriel
  • Escalante Sandoval, Carlos
Se discuten las bases matemáticas fundamentales de la modelación borrosa en términos de la función de membresía. Se presenta un modelo para la predicción de avenidas a tiempo real a partir de inferencias borrosas y bajo la hipótesis de que la información disponible es escasa. Para construir el modelo, el problema es dividido en tres etapas. En la primera de ellas, se infiere el tiempo pico a partir del gasto base inicial. En una segunda etapa se determina el gasto pico. Finalmente, se infieren las restantes variables temporales que dan forma al hidrograma de la avenida a partir de una correlación lineal ordinaria. Se discute la mejora sustancial de la respuesta del modelo al agregar nueva información. La metodología propuesta se aplica exitosamente al registro de avenidas máximas en la estación Huites, México. Los resultados obtenidos son muy satisfactorios.
Proyecto:


Secció docent i problemes

  • Ruiz Espejo, M.
  • Alonso, R
Peer Reviewed
Proyecto:


La educación superior en Argentina: balance de un milenio

  • Mollis, Marcela
En Argentina, el mal llamado «sistema» de educación superior constituye un conglomerado institucional complejo y heterogéneo, conformado por más de 1.700 establecimientos de nivel terciario no universitario y por 102 establecimientos universitarios. Las 102 instituciones universitarias oficialmente reconocidas en el país hasta el año 2007 están integradas por 38 universidades nacionales, 41 universidades privadas, seis institutos universitarios nacionales creados bajo el régimen legal de universidades provinciales y 14 institutos universitarios privados, una universidad provincial, una universidad extranjera y una internacional. Todas ellas configuran un mapa cuyos rasgos más característicos son la complejidad, la diversidad y una heterogénea multifuncionalidad., Peer Reviewed
Proyecto:


Un (des) encuentro: Barcelona busca su puerto: análisis de los cambios de la ciudad en base al desarrollo de su puerto (Port Vell)

  • Piedra, Ana María
El puerto, como base material de las actividades de la ciudad, es un elemento integral en el desarrollo de la misma. Está influenciado por fuerzas locales y globales que exigen de la ciudad un ritmo de desarrollo distinto, generando un desbalance que resulta en una separación paulatina del puerto y la ciudad en diferentes etapas. La presente investigación analiza los planes de desarrollo de la ciudad, del puerto y su interrelación, destacando cambios relevantes en la estructura urbana ligados a los cambios del puerto., The port is an integral element of the city’s development as it is the material base of its activities. Local and global forces influence the port and require a distinct development pace in a city, thus, creating an imbalance that results in a gradual separation of the port and the city at different stages. This study analyzes the city and the port development plans, as well as their interrelation, highlighting the significant changes in the urban structure linked to the changes in the port.
Proyecto:


P-slice based efficient speculative multithreading

  • Ranjan, Rakesh
  • Marcuello Pascual, Pedro
  • Latorre Salinas, Fernando
  • González Colás, Antonio María
Microprocessor industry has recently shifted towards multi-core to take advantage of the ever increasing number of transistors provided by the new technologies. Unfortunately, the multi-core approach does not allow single threaded applications to benefit from the additional cores to improve their execution time. Speculative multithreading (SpMT) has been proposed in the past to boost performance of irregular applications in multi-core environments. In this work, we study the main bottlenecks of these architectures, such as the memory behavior and the pre-computation slices and propose two novel schemes that allow SpMT to get 25% average speedup over single threaded execution. We propose Selective Replication as a technique to improve the performance of the SpMT memory system. This technique does not introduce additional traffic in the bus and improves the performance of a conventional SpMT memory model by 6% on average and up to 21% for some applications. Also, we propose a scheme called Slice Specialization that reduces the number of instructions in the pre-computation slices by adapting the slice to every single speculative thread spawned. The later proposal outperforms previous schemes with slices by 15% and overall, both techniques combined achieve an improvement of 20% over a conventional SpMT processor.
Proyecto:


The cgm and the fdtd for sar studies

  • Pous Andrés, Rafael
  • Mallorquí Franquet, Jordi Joan
  • Bayonas, F
In the study of electromagnetic radiation effects over dielectric bodies, effective numerical methods are needed. At present, there is a lack of tools for measuring these effects and due to the huge growth of microwave devices, like cellular radio telephones working close to the human body, it is necessary to develop accurate numerical methods for evaluating those effects. Two of the most efficient and extensively used methods are the FFT-CGM (fast Fourier transform-conjugate gradient method) and the FDTD (finite difference time domain method). Since both methods use a rectangular grid, it is interesting to compare the two solutions in order to validate the results. Algorithms for solving the two-dimensional scattering of transversal magnetic (TM) polarized waves by a lossy dielectric objects are presented. At the same time, the SAR (specific absorption rate) of tissues is obtained from the diffracted fields., Peer Reviewed
Proyecto:


Trace ions rejection tunning in NF by selecting solution composition: Ion permeances estimation

  • Pagès Hernando, Neus
  • Reig i Amat, Mònica
  • Gibert Agulló, Oriol
  • Cortina Pallás, José Luís
Nanofiltration (NF) is suggested to selectively remove ionic species in aqueous process streams taking benefit of both membrane and aqueous solution composition. The importance of predicting and optimizing selective ion rejections by NF not only of major compounds (e.g. NaCl, Na2SO4, MgCl2, MgSO4) but also of minor ones such as ammonium (NH4+), nitrate (NO3-), bromide (Br-), iodide (I-) typically present in natural and industrial process streams is crucial. The current work explores ion rejection patterns and membrane ion permeances using the phenomenological Solution-Electro-Diffusion-Film (SEDF) model. It makes possible rapid calculations that account for the effects of spontaneously arising electric fields on rejections. Experimental ion rejection data of several inorganic ions species at various transmembrane pressures and at fixed cross-flow velocity have been obtained with NF270 membrane. A number of trace ions (Na+, K+, Cl-, Ca2+, Mg2+, SO42-, NO3-, NH4+, Br-and I-) have been used in combination with various dominant salts (NaCl, MgCl2, MgSO4) as model feed solutions. Results showed that dominant salts were moderately (NaCl) and highly (MgCl2, MgSO4) rejected when some ions are divalent, while trace ions exhibited quite variable rejection, including negative ones mainly at low transmembrane volume flows. The electric field of membrane potential can accelerate or retard the ion flows to the permeate, so negative or unexpectedly high rejections could be observed. Ions transport was shown to be affected by the membrane chemistry (e.g. acid-base properties of the un-crosslinked carboxylic and amine groups) and the dielectric exclusion phenomena. From the modelling procedure, ionic membrane permeances were determined for various multi-ion systems studied. Results showed that nature of dominant salt composition can be used to control the rejection of minor components., Peer Reviewed
Proyecto:


New results on stabbing segments with a polygon

  • Díaz Bañez, José Miguel
  • Korman Cozzetti, Matías
  • Pérez Lantero, Pablo
  • Pilz, Alexander
  • Seara Ojea, Carlos
  • Silveira, Rodrigo Ignacio
We consider a natural variation of the concept of stabbing a set of segments with a simple polygon: a segment s is stabbed by a simple polygon P if at least one endpoint of s is contained in P, and a segment set S is stabbed by P if P stabs every element of S. Given a segment set S, we study the problem of finding a simple polygon P stabbing S in a way that some measure of P (such as area or perimeter) is optimized. We show that if the elements of S are pairwise disjoint, the problem can be solved in polynomial time. In particular, this solves an open problem posed by Loftier and van Kreveld [Algorithmica 56(2), 236-269 (2010)] [16] about finding a maximum perimeter convex hull for a set of imprecise points modeled as line segments. Our algorithm can also be extended to work for a more general problem, in which instead of segments, the set S consists of a collection of point sets with pairwise disjoint convex hulls. We also prove that for general segments our stabbing problem is NP-hard. (C) 2014 Elsevier B.V. All rights reserved., Peer Reviewed
Proyecto:


Implementación de un juego de programación visual para la docencia

  • Diez Garrido, Gonzalo
Proyecto de implementación de un videojuego, donde el objetivo de este es que el usuario aprenda los conceptos de programación y lógica, creando programas a base de arrastrar y soltar bloques de código, que moverán a un robot para superar un nivel. Realizado con C++ y la librería múltimedia SFML., Project of implementation of a video game, where the objective of this is that the user learns the concepts of programming and logic, creating programs based on drag and drop blocks of code, which will move a robot to overcome a level. Made with C ++ and the SFML multimedia library.
Proyecto:


Buscador avanzado