PHYSICS, 3

Author: Castro Otero Emilio.
Year: 2006.
University: SANTIAGO DE COMPOSTELA.
Place of defense: Facultad de Física.
Place of preparation: Facultad de Física.

Summary: This memory TEsis Doctoral has been conducted in the Laboratory of Physics of Colloids and Polymers of GRupo Systems Compeljos Department of Condensed Matter Physics at the University of SAntiago de Compostela. Since qeu a priority objective of the research project qeu is leading the research group on characterization of block copolymers consisting of hydrophilic basis (ethylene oxide) and hidrófoba (propylene oxide, butileno and styrene) as emdio transport and solubilization of drugs is to get a critical size of 5 nm, which ensures that the active ingredient can be released anywhere in the human body. This is plentaean two possibilities: On the one hand, generate a new class of copolymers that could achieve that size caracteríostico and on the other, changing the size of agregadosn formed earlier copolñimeros based blocks oxifeniletileno and oxietielno by adding additives to the dissolution: surfactants and cosolventes. Doctoral Thesis This covers the second of the potential proposals. The set of experiences gathered in this study includes Doctoral Thesis five polymers, posibilitanto analysis of the influence of molecular architecture and the length of the blocks in nanostructures formed. As additives has employed a polar solvent miscible with water (ethanol) and several ionic surfactants, which have enabled an analysis of the influence of hydrophobicity and the nature of the electric charge in the modulation of nanostructures formed. Thus, the first chapter is an introduction on the nature of block copolymers, briefly reviewing the control mechanisms and structural stability of the same. In the second chapter is a brief explanation of the técnuicas pilot employed more relevant to the course of presnete work. In the third chapter, we present the results obtained from the characterization físcio-química for copolymers studied, and explores the modulation of the rpesencia of estanol in meduio as a mechanism for controlling structural aggregates formed by the copolymers. The fourth chapter contains discussion of experiments on systems copoliméricos in the presence of ionic surfactants, analyzing their em, job as a regulatory mechanisms morphological and structural polymeric nanostructures. Finally, in the fifth chapter is a comparison between the two types of structural control, being that this work is accomplished with the objectives previously envisaged.

Author: DA SILVA GONZALEZ JESUS IVAN.
Year: 2006.
University: LA LAGUNA.
Place of defense: FACULTAD DE FISICA.
Place of preparation: FACULTAD DE FISICA.

Summary: The work in this focused mainly on the study of the processes leading to the implementation of Direct Methods, the resolution crystal structures ab initio from powder diffraction data, and is structured as follows:

Author: HERNANDEZ ALONSO SERGIO ELIAS.
Year: 2006.
University: LA LAGUNA.
Place of defense: FACULTAD DE FISICA.
Place of preparation: FACULTAD DE FISICA.

Summary: The thesis presents the principal tasks developed for the finalization of a ticnica for measuring parameters hemodinámicos in vivo by Reflectance spectroscopy of Media Dispersivos, ERMD. These tasks are: "The realizacisn several prototypes with the goal of studying hemoglobin solutions in vitro and tissue biolsgicos in vivo." Due to the non-linearity between concentrations of cromsforos and absorbance spectra measured in one important task was to develop the mitodo to obtain absolute concentrations of cromsforos studied, mainly: oxihemoglobina and deoxihemoglobina. This development can be broken down into: o simulacisn to travis two different variants of Mitodo Monte Carlo behavior of light in dispersive media. The study or in vitro dissolution spticamente dispersive of the main parameters that characterize the ERMD. Or Posterior aplicacisn in vivo results obtained using Monte Carlo simulations and in vitro measures.

Author: LOPEZ SOLANO JUAN JAVIER.
Year: 2006.
University: LA LAGUNA.
Place of defense: UNIVERSIDAD DE LA LAGUNA.
Place of preparation: UNIVERSIDAD DE LA LAGUNA.

Summary: The methods of theoretical study of the art of so-called first principles (or ab initio) have developed remarkably in recent decades. These methods make it possible at present to obtain a wide range of information on very complex systems, using only tools and principles of Quantum Mechanics. Using these methods first principles, in this thesis has studied the effect of pressure on the two types of crystalline solids different compound binary InAs, and the five materials ternary YLiF4, CaWO4, SrWO4, BaWO4 and PbWO4. In both cases have been studied mainly structural phase transitions under pressure. The study of the compound InAs, ab initio calculations performed correctly reproduce the experimentally observed behavior pressures moderate, with transitions from the structure zb pressure environment towards type NaCl, and it towards Cmcm. At elevated pressures, have been discussed several structures proposed in InAs as stable at high compression phases, such as the type structure CsCl proposal on the theoretical work of Mujica and Needs [Phys. REV. B 55, 9659 (1997)]; estructurtas type B10 and Pmma, and theoretically studied by Kim and colleagues [Phys. REV. B 60, R8449 (1999)]; and structure type Pmma disorderly characterized experimentally by Pascarelli et al. [Europhys. Lett. 61 (4), 554 (2003)]. It has also considered the type structure Super-Cmcm proposed as a stable compound InSb by Kelsey and Ackland [J. Phys.: Condens. Matter 12, 7161 (2002)]. In addition, it has analyzed the impact of the organization on the stability of the network bcc (which belongs to the type structure CsCl), which leads to structures casi-bcc such as type B11, which presented the remarkable difference with respect the first type CsCl have neighbors of the same type. Structures of this type have not been studied in any previous work in this type of compounds, as seen volatile due to the forces of repulsion between atoms of the same element. The study shows a steady state rate Super-Cmcm stable after the type Cmcm, similar to what happens in InSb. In pressures in excess of 60 GPa, the phases are found to be more stable structures casi-bcc. In compounds such as InAs low ionicidad of links translates into some power between different atoms and the same type very similar. This allows these structures casi-bcc submit distances first neighbors of the same type very short, and a packaging than the type structure CsCl. This study also shows that the behavior under pressure from the crystal lattices formed by a single element (ie, only crystals of In and only Ace) also plays an important role in the stability of structures bcc type compound InAs. It should be noted that while such structures have not been observed experimentally in InAs, have been detected structures labeled as bcc messy in several compounds, such as InSb. This study of first principles can therefore help clarify the situation of high pressure in these compounds. The study of the five compounds ternary YLiF4, CaWO4, SrWO4, BaWO4 and PbWO4 has helped establish a number of general characteristics of behavior under pressure of the compounds of this type (commonly known as compound ABX4). The five compounds analyzed crystallizes in the form of scheelita and suffer behavior under pressure whose similarities and differences can be understood based on the diagram Bastide [JP Bastide, J. Solid State Chem. 71, 115 (1987)] and the application to it of the so-called rule NE. That rule is a law semi-empírica that stable high-pressure structures of a compound found NE of the position in the diagram of the Bastide estr 8 uctura d 10ff and pressure environment. The systematic study of 5 compounds has enabled different check the validity and limitations of this rule, so that indeed the study of these compounds has led to general information about their behavior under pressure from the compound type ABX4. The study of the compound YLiF4 has considered several proposals before structural sequences [Grzechnik et al, Phys. REV. B 65, 104102 (2002); Sen et al. Phys. REV. B 68, 134105 (2003), Li et al. J. Phys.: Condens. Matter 16, S983 (2004)], concluding that the transition scheelita aM (premium) -fergusonita is favored at least at low temperatures. Based on this transition has been able to explain certain anomalies observed in experiments Raman [Sarantopoulou et al. Phys. REV. B 59, 4154 (1999), Wang et al. ArXiv.org: cond-mat/0210491 (2002)]. At higher pressures, this study shows as a more stable phase structure of the group space n No. 64, Cmca with 8 formulas unit in the conventional cell. This structure has been obtained for the first time in these calculations and its pressure appearance, as well as the characteristics of the transition, appeared in good agreement with the observations of Grzechnik and collaborators, who were unable to completely characterize the third phase structural YLiF4. The study of the four wolframatos Ca, Sr, Ba and Pb has been carried out in close collaboration with experimental groups from the Universities of Valencia and Valencia Polytechnic. The behavior under pressure from CaWO4, according to the pilot and theoretical calculations, it is very similar to that of YLiF4, which is in accordance with the proximity of the two compounds in the diagram Bastide. The combination of theoretical and experimental techniques has allowed understand the complex situation of structural stability in the compounds SrWO4, BaWO4 and PbWO4. Phase stable after scheelita kind of pressure environment in these three wolframatos is, according to the theoretical calculations, the type PbWO4-III (BaWO4-II) structure which had been previously observed under high pressure and high temperature in wolframatos Pb (Ba). At low temperatures, measured diffraction X-ray did not show, however, the existence of such a structure, while Raman measures find traces of it in coexistence with other phases. As shown in theoretical study, the transition from scheelita towards a structure type PbWO4-III is strongly of the first order, which is a major reorganization of the atomic positions and the need to overcome barriers kinetic high. Thus, the Raman techniques, to be very local, observed portions of the glass have traveled to phase PbWO4-III pressure reduced, while the X-ray diffraction techniques, able only to identify general changes in the sample, only the stage show kind PbWO4-III pressure very high, when it had passed the barriers kinetics and the whole sample has gone toward PbWO4-III. At intermediate pressures can even be a partial transition towards fergusonita, because in this case no kinetic barriers to overcome when it comes to a transition from 2 fourth order. It should be noted that theoretical studies have provided information on structural parameters and Raman frequencies that have helped characterization experimental stages observed. A very high pressures, theoretical studies in the four wolframatos predict the stability of the structure type Cmca already indicated that it would appear as a general feature in this type of ternary compounds.

Author: MARTINEZ GONZALEZ MARIA JESUS.
Year: 2006.
University: LA LAGUNA.
Place of defense: UNIVERSIDAD DE LA LAGUNA.
Place of preparation: INSTITUTO DE ASTROFISICA DE CANARIAS.

Summary: In this dissertation is a study of the magnetic properties of the Sun calm in those regions where the sun magnetism passes almost unnoticed. It concludes that magnetic fields are weak, a few hundred Gauss, filling a small portion of the element resolution. In addition magnetic structures in these regions seem to have a very complex topology forming a medley of small loops.

Author: Espinal Curull Javier.
Year: 2006.
University: AUTÓNOMA DE BARCELONA.
Place of defense: Instituto de Física de Altas Energias (IFAE).
Place of preparation: Instituto de Física de Altas Energias.

Summary: The axial-vector mass is measured using charged current quasi-elastic neutrino-carbon interactions within the framework of the K2K experiment.

Author: BRESOLI CATA FRANCESCA.
Year: 2006.
University: AUTÓNOMA DE BARCELONA.
Place of defense: D.FISICA.
Place of preparation: UNIVERSIDAD AUTONOMA DE BARCELONA.

Summary: Short abstract: At the beginning of the thirties, the number of known particles in the nuclear physics world was near half a dozen. At the end of the fifties, tables of particles included more than thirty. In the middle of the two periods, it is found the item of our research: the discovery of strange particles. These particles were mainly identified in the cosmic radiation, analysed and classified through the theory of strangeness and experimentally tested with the new accelerators.

Author: LUIS BRIÑAS LÓPEZ.
Year: 2006.
University: ALICANTE.
Place of defense: ESCUELA POLITÉCNICA SUPERIOR.
Place of preparation: UNIVERSIDAD DE ALICANTE.

Summary: Faced with the problem of diagnosis submitted by affected by Marfan's Syndrome, it is proposed to conduct a morphometric analysis of the affected relative to the normal population, by making anthropometric measures of the different parts of the human body and the use of anthropometric indices . It is also proposed as a supplementary force making develop in both hands and has been making a questionnaire autodescripción physics. Therefore, the purpose of this thesis is, therefore, propose a model for morfométrico man and woman characteristic of the subject affected by Marfan's Syndrome with anthropometric indices that identify and diagnose a measurable, objective and automatic disease before it appears at the grave problems that usually give.

Author: VILLANOVA DEL MORAL ALBERT.
Year: 2006.
University: VALENCIA.
Place of defense: IFIC - INSTITUT DE FÍSICA CORPUSCULAR.
Place of preparation: FACULTAT DE FÍSICA.

Summary: Recent results of neutrino experiments have shown that the Standard Model is to be extended to explain the experimental data. Faced with this situation, many models of neutrino mass has been proposed. However, the mechanism responsible for the generation of masses is still unknown. In order to understand it, they checked two conditions: firstly, the models must be verifiable on the other hand, different models must be distinguishable. Therefore, it is necessary to conduct a detailed analysis of the different models of neutrino mass to identify their specific properties and their phenomenological implications. This type of study has been the main motivation for this thesis. In fact, it deals with the study of different models of neutrino mass and the investigation of its implications. Among the models studied, some of them are based on the symmetry discreet flavor A4. This symmetry can be done in many different ways depending on the content of particles in the model and the transformation of these properties under A4. One of the achievements studied in detail this is a model that predicts neutrino masses quasi warped. The content of particles is the same as in the Standard Model Supersimétrico minimum, but with extended superfields leptones, quark and Higgs, singletes under SU (2). The main results of this model are: mixtures of neutrinos and the sleptones are correlated; predicts the existence of a sleptón with mass accessible in the LHC, establishes a lower bound on the scale of absolute Majorana mass of neutrinos; predicts processes that violate flavor leptónico with lower levels accessible to the next experiments. In another achievement of symmetry A4, the content of particulates is widespread respect to the Standard Model Higgs with three doubles and four of the Higgs triplets. The most important results are: angles mixture of atmospheric neutrinos and reactor are maximum and zero respectively; predicts a lower bound for the magnitude of the double beta decay without emission of neutrinos, and this peak is independent of whether the hierarchy neutrino is normal or reverse, or whether it is retained or not CP symmetry. Unlike conducting A4 discussed previously, it no less important benchmark for the scale of absolute neutrino mass. It has been studied the pattern mixing bimáximo, which is a common feature, for example, many models of neutrino mass-based A4. Assuming that this pattern is valid at high energies, is its evolution at low energies including radiative corrections (both of the shift by Equations Group Renormalización as the threshold) and taking up part of mSUGRA (universal and independent of taste ). The conclusion of this work is that the mixing angle of solar neutrinos can only increase with respect to its value tribimáximo reference, while the angles and atmospheric reactor remained essentially stable. On the other hand, have been studied generation models of neutrino mass rape by parity R. Specifically, it has conducted a detailed analysis of two specific models. First, it has been considered a model with explicit violation bilinear parity with Ry superfields of Higgs triplets. The most outstanding results are the expected values in a vacuum of the components of the neutral Higgs bosons of triplets cuadráticamente depend on the parameters of parity violation bilinear R; explicit violation bilinear parity R generates massive scale atmospheric neutrinos while the scale of the solar neutrino mass is generated by the Higgs triplets; branchi 8 ng ratio a93 of the decay leptónicas's hat-trick of doubly charged Higgs are associated with the mixing angle of solar neutrinos, this unit is shown explicitly. Under the model neutrino mass spontaneous rupture through parity R has been studied in detail the sector of Higgs bosons neutral. The most relevant results are: some specific variants of this type of models can solve the problem of mu in the same way as does the Standard Model Supersimétrico Cuasi Minimum; there is a bosón of Nambu-Goldstone (without mass) associated with spontaneous rupture number leptónico called majorón; there is a bosón of neutral Higgs pair COP is light (available on LHC) whose production is the same as that of bosón of the Higgs MSSM but can be dominant channel disintegration invisible, although not so generic (as in the case of Higgs bosons in pairs under COP), there are parts of the parameter space where bosón of neutral Higgs odd low COP lighter may have both production division as invisible considerable disintegration. In short, this thesis has been discussed in depth several models of neutrino mass. As a result, they have been predicted different experimental observables, which are verifiable in the next generation of experiments: a lower bound for the rate of double beta decay without emission of neutrinos; lower bounds for processes that violate flavor leptónico and signals in accelerators, such as a bosón of doubly charged Higgs whose break leptónicas are related to the mixing angle of solar neutrinos, a sleptón light of Higgs bosons or to disintegrate invisibly so dominant. We hope that this work will prove useful to verify the models studied and eventually help to understand the mechanism responsible for generating mass of neutrinos.

Author: Rosell Escribà Ignasi.
Year: 2006.
University: VALENCIA.
Place of defense: Facultat de Física.
Place of preparation: Facultat de Física.

Summary: In this thesis suggests the use of the theory of Quiral Resonancias to describe QCD at intermediate energies. This model uses the ideas of lagrangianos phenomenological proposed by Weinberg. The expansion is used in a wide range of colors as a parameter expansion and a fundamental point is the use of the behavior of QCD at high energies. The aim of the thesis is to make a first step towards taking account of quantum corrections in this model. It first calculates the vector form factor of pión to order subdominante. This estimate allows us to see that the count is well defined, we can predict chiral couplings to order subdominante and shows the need to consider the form factors with resonances as states asintóticos. Following these ideas, it is estimated the difference in the function of two points from two streams scalar and pseudoescalares, allowing predict links chiral L (8) and C (38), keeping track of the dependency scale. We have studied all the ligatures that come to consider the form factors of two bodies in the field of intrinsic pair of parity theory. Lastly, the study of renormalización a loop with only scalar resonance and pseudoescalres allows us to verify the proper functioning of saturation by the resonances of links chiral linked to these resonances, in order subdominante.

Author: MARTÍNEZ MORENO EDUARDO.
Year: 2006.
University: VALLADOLID.
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS, UNIVERSIDAD DE VALLADOLID.

Summary: In this paper we use a method of semi-strong ligatures (TB) in combination with the method of first principles TB-LMTO to obtain the electronic structure and magnetic properties systems in transition metal compounds such as Cr, Mn, Fe and Ni . The method used allows TB treatment of non-collinear magnetic configurations, typical systems that present magnetic frustrations. As well as performing calculations on systems with a large number of positions inequivalentes in a reasonable time. The systems studied are those for aggregates Fe supported Neither different orientations cristalográficas, films supported Mn Fe (001) and Cr films supported Fe (001). In the case of aggregates of Faith in Ni, results are obtained structural and magnetic according to recent experiments. It also explores the interactions between aggregates supported, very important under the technological point of view. In films on Mn Fe, are regarded films of different thicknesses supported on substrates ideals (without stairs monoatómicos at the interface) and then finds the presence of steps at the interface. The results are in very good agreement with recent experiments performed with technical SP-STM/STS. In films Cr Fe is done on a comparative study between Cr and Mn when they are deposited on Faith, getting quite different behavior between these materials. Finally, we consider systems with interdifusión Cr-Fe, since under the experimental point of view it is very difficult to avoid this phenomenon.

Author: Fernández Banqué Ferran.
Year: 2006.
University: AUTÓNOMA DE BARCELONA.
Place of defense: Laboratori de Llum de Sincrotró.
Place of preparation: Laboratori de Llum de Sincrotró.

Summary: In light of synchrotron facilities, requires detectors with a good spatial resolution and a high rate of local accounts to conduct experiments on x-ray diffraction time scales below the millisecond. Due to the small distáncias between electrodes, gas detectors of micro-fabricación (MPGD) can meet these requirements. But these devices pose two major problems: the emergence of electric shocks and continued degradamiento its functionality over time. In this project we present a new detector gas micro-fabricación: Micro Mesh Reading Chamber (MRMC). Its design is based on a mesh formed by two flat electrodes reading deparados by a dielectric. This mesh is separated by a resistive anode pillars that set the zone multiplying the load. For its design, which is intended to eliminate the problems presented by MPGD, there have been a series of detailed simulations of various aspects of the detector. These simulations verified experimentally, have been used to sort the parameters of the detector to optimize the capabilities of the same. The first laboratory tests show promising results certifying the resistance of the detector and predictions of the models.

Author: DELFIN SILIO SALCINES.
Year: 2006.
University: POLITÉCNICA DE CATALUÑA.
Place of defense: E.T.S.DE INGE. INDUS. Y DE TELECO..
Place of preparation: ESCUELA TECNICA SUPERIOR DE INGENIEROS INDUSTRIALES Y DE TELECOMUNICACION.

Summary: In this thesis develops and implements a procedure to simulate the operation of wind systems, in order to predict the amount of energy removable by these devices at a specific site. There will always be a dynamic model of the different elements of the installation (wind resource, aerodynamics, mechanical transmission, electrical machine, and control of the set) for two types of wind turbines, a steady speed and other variable speed. Outputs from the model help determine the power curves of wind turbines depending on the speed and level of wind turbulence. The study provides results regarding the influence of the capture of energy from wind turbines in the same component aerodynamics and different control schemes. There will always be a sensitivity analysis of various parameters involved in the models to predict the direction in which it develops a concept gain control against another, when amending certain parameter. It has developed a specific software for the global model, implemented in prgrama Simulink platform of Matlab.

Author: CASTRO CARBALLO MARÍA ELENA.
Year: 2006.
University: SANTIAGO DE COMPOSTELA.
Place of defense: FACULTADE DE FÍSICA.
Place of preparation: FACULTADE DE FÍSICA.

Summary: and that is intended to give explanation to the doubts raised by the Standard Model. The LHC is being built at CERN (European Organization for Nuclear Research) in Geneva (Switzerland) and in 2008 will be ready to produce collisions of protons to an energy of 14 TeV. The use of superconducting magnets needed to achieve high-energy, high "lightness" required to do Physics, llimitada opening dynamics and energy stored in bundles protenes, will make the control of this vast machine is a challenge, especially during its injection of protons and increased energy. Two particular problems of this accelerator will be the high sensitivity loss of particles in the beam and a poor quality of the magnetic field, which required the use of elements of correction. The injection and acceleration of protons in the LHC without loss of particles and growth parameter called "emitancia, require precise control of the parameters that characterize the beam. The value called "beatron tune," ie, the number of oscillations cross the orbit conducting particles per period of revolution, will be about 63 units and need to be controlled with an accuracy of 0,003. Tours of the nominal orbit must be liminadas to less than 0.5 mm. The chromaticity should be restricted to a few units. Controlling this accelerator will bring a high difficulty as it will be necessary to use instruments ocntrol and diagnostics to ensure the stability of the beam particles and avoid the most disturbing phenomena are necessary to carry out the extent of the characteristic parameters of this type machines. 2 .- OBJECTIVES The thesis examines two prototypes of diagnostic tools for measuring key parameters describing a beam of particles when they are being accelerated in a circular knitting machine, and for which the operating principle should be compatible with the stringent requirements sensitivity of the LHC taxes for high intensity. The work is divided into two parts: 1 .- The tests carried out a diagnostic tool known as "Schottky monitor" and possible application in the LHC. 2 .- The improvement in the sensitivity in the ability to measure a "monitor Head Tail." Behind the two themes there is a common goal and that is the need for new methods of measurement and diagnosis of accelerated particles with charges, which are highly accurate and non-destructive, fundamental conditions for maintaining the limited tolerances imposed on the superconducting accelerator that is the LHC.3. SUMMARY OF RESULTS Following previous experiences made with Schottky monitors already are used in other acelereadores and through collaboration with FNAL (USA), a pick-up-type Schottky, cipia of soinstalados in the rings and Tevatron Recycler of FErmilab was tested in the SPS to study suposible application as a diagnostic tool, not destructive in the LHC. Analysis of data acquired in the SPS with a beam of particles with the same structure as that supplied the LHC, showed the consistency of the frequency spectrum with those obtained in both transverse and longitudinal with the theory predicts that the Schottky. At the same time, the response of the pick-up corresponds to the expected levels according to the calculations, and valaores drawn to the tune betatrón, chromaticity and the variation of linear time are approximately equal to those in the SPS during the at that stage it was making data. One could make a complete diagnosis transverse beam 8 partícul d97 as using this monitor tuned to 1.8GHz if possible eliminate some of the elements that corrupt spectra in frequency: revolution lines that are a result of displacement of the beam center the pick-up and can hide bands in the tune betatrón that overlap to you and incoherent in which the breadth and width may be affected by other effects other than the variaicón the moment and the chromaticity, parameters can be obtained from Schottky spectrum, and finally, the frequency components associated with the noise caused by the elements that make up the chain of acquisition of data. Sepodrían make further evidence "pilot beam" to see the monitor sensitivity to a single cluster of particles present in the beam. The need to increase sensitivity to fluctuations in the head and cross dela queue ung rupo particles in the "Monitor HEad-TAil" installed on the SPS, led to the construction of a prototype of a system for correcting orbit beam when particles passpor a cavity-type "stripline coupler." This limits the signal cross resutlante the diversion of electric beam from the center of the cavity and that only provides information about the degree of displacement. Removing this component of the displacement would decrease the disturbance applied to the beam particles and which is necessary for the emergence of oscialciones of the head and tail of the group. This system consists of a loop realimentaicón whose entry the position of the beam and outputs the tensions that control the attenuation applied to the electrodes of the pick-up and focus on electronic position of the beam. The results obtained with two different control algorithms (P Pl) showed that it was possible to eliminate unwanted signal cross in a 70%. It should put more énfaseis in control algorithms: trying to determine accurately the state for which the particle beam is focused on the pick-up and integrate variable in the most appropriate algorithm and try to build a kind of PID algorithm for further rapid changes in the position of the beam. 4 .- FINDINGS AND FUTURE PLANS Overall can ocncluir that the results of this work, laying the groundwork for further investigate the possible application of a monitor Schottky in the LHC because the preliminary results are quite promising. In the case of the monitor Head-Tail, it might be feasible to build a system of full compensation, inlcuyendo correct orbit on two levels, X and Y. With the new prototype, it would be important to make steps chromaticity and compare them with those obtained without copensación the diversion of the orbit.

Author: SEOANE IGLESIAS NATALIA.
Year: 2006.
University: SANTIAGO DE COMPOSTELA.
Place of defense: FACULTAD DE FÍSICA.
Place of preparation: FACULTAD DE FÍSICA, UNIVERSIDAD DE SANTIAGO DE COMPOSTELA.

Summary: The semiconductor devices are scaled to dimensions on the order of nanometers with the aim of improving increasingly performance. The scaling of devices such drastic increases the importance of certain sources of fluctuations related to the nature atomística of cargo and matter, which is becoming a factor determining the reliability and performance of the devices, and therefore circuits manufactured with them. In the past, the gap in cornering characteristics of the transistors was mainly associated with variations in the parameters of manufacturing, which generated macroscopic variations in the thickness of the layers, geometry and the doped. However, the sources of fluctuations charged importance with the downsizing of the devices are independent of the lithographic processes and can not be eliminated through improvements in the manufacturing process. So, while in the numerical simulations conventional devices were treated as perfect, with interfaces and soft borders and continuous distributions of doped, now no longer possible to consider a single device perfect, but it will be necessary to simulate a set of different transistors microcosmic level, since, if one considers a range of devices, including various types of intrinsic parameter fluctuations cause statistical variations between them. The sources of fluctuations inherent parameters that affect the devices are three-dimensional in nature and thus, to capture properly the effects they cause is required simulations 3D. Another consideration to keep in mind is the need to simulate a set of statistical devices big enough to enable draw with sufficient precision parameters that characterize the distribution statistics. Therefore, the technique chosen for the simulation of these effects must be swift and efficient, allowing the simulation of a large device within a relatively short period of time. Therefore, the simulator device used in this work is three-dimensional and is based on approximate arrastre-difusión, which represents the model simpler and less costly, from the point of view of computational resources required, which is used in multi-dimensional simulations . The major problem associated with the three-dimensional simulation is its high computational cost, determined by the large amount of information involved and the huge numbers of calculations to be performed. Moreover, in this particular case, endorsed the need for statistical analysis, which increases the computational cost by the size of the statistical sample. These two factors mean that the use of conventional computers in solving these problems is prohibitive and generate the need for the use of parallel machines. Therefore, the simulator 3D device used in this work is parallelised through the library of MPI message passing, using the programming languages C and Fortran, thus ensuring code portability. The work has been divided into five chapters, which seeks to give, first, an overview of the process simulation of semiconductor devices and secondly, the result of its application to the study of intrinsic parameter fluctuations in devices HEMT . The first chapter introduces the basic principles of the devices HEMT, whose behavior is studied later in the three-dimensional simulator devices. The transistors HEMT are composed of semiconductor heterostructures. To do so, initially describes the physical principles underlying the heterostructures, to address the following description of the field effect devices based heterostructures and its operation. Finally summarizes some of the applications and utilities current devices based heterostructures. The second chapter inicialme 8 nt d 1ff8 write is the main technical simulation of semiconductor devices used currently. Here is the model arrastre-difusión since it is used in the simulator 3D devices, describing the mathematical equations that make up this model, the equations of continuity and Poisson carriers. He then introduces the finite element method, used in the discretization of equations that make up the model arrastre-difusión. The Poisson equation is discretized using the standard method, whereas in the equations of continuity of electrons and holes has used the discretization of Scharfetter-Gummel since it leads to better results. In the third chapter initially mentioned the main stages that make up the simulation process. Then, in the different sections of the chapter describes in detail each of these stages. First is the process of generating and partitioning the finite element mesh modeling device discretizado. Secondly, we study techniques linearization system discretizado which often applied in this area, the de Newton-Raphson method and the method of Gummel. He then discusses the methods of resolution that can be used for solving linear systems, direct methods and iterative, along with preconditioners used to accelerate the convergence of iterative methods, because in this particular case are the most efficient in solving the linear systems. He then introduces the concept of reordering matrix dispersed and displayed various formats of these storage arrays. In conclusion summarizes the implementation of the various stages that make up the process of simulation devices in the simulator 3D parallel model drag -- dissemination. In the fourth chapter presents various optimizations simulator 3D device used in this work, seeking to minimize the time simulation. For optimization are different strategies and improvements in runtime obtained after application. So, first listed the characteristics of parallel computer, a cluster HP Integrity Superdome, used in obtaining all results presented in later sections. Secondly is seeking algorithms resolution linear systems best suited to our problem, doing it for an analysis of the settlement methods and techniques available preconditioning, and the parameters that are more important in the time execution. Once obtained methods resolution more efficient, thirdly are looking to optimize the entire stage resolution of the linear systems of equations implemented in the simulator, as this is the most expensive phase of the whole process. Finally, it presents a new strategy partitioning mesh devices HEMT used in a manner that takes into account the physical nature of the phenomenon under study. The fifth chapter deals with the impact of fluctuations in parameter curves intrinsic characteristics of the devices HEMT. To do so, as noted previously, there is a need for statistical analysis of the results obtained. Therefore, in this chapter, initially defines certain basic statistical concepts to be used in subsequent paragraphs. Secondly discusses the main advantages and disadvantages of using approximate arrastre-difusión for the simulation of the effects of fluctuations intrinsic parameters. Thirdly describes the structure of the two devices used in the study, a device PHEMT of 120 nm in length door with a channel InGaAs with a content of 0.2 and In a HEMT of 50 nm gate length with a channel of InGaAs containing In-0.7. . He then mentioned the major sources of intrinsic fluctuations that may occur in MOSFET devices, since these effects in these devices have been widely studied. On this basis, in the following section describes, in a more detailed, the main sources of fluctuations affecting the HEMTs and which have been analyzed in this paper. To conclude this chapter presents the numerical results obtained from this analysis. This study was performed separately for the two devices studied, trying three different sources of fluctuations, the random variation of the composition of ternary compounds that form the channel of the device, the influence of the discrete nature of atoms doping and random variation in loading interface between two borders of this device. All this analysis focuses on the influence of intrinsic parameter fluctuations in the flow of drenador, although it must be borne in mind that fluctuations may affect other variables. Finally, it shows a study of the impact of fluctuating parameters inherent in the cutoff frequency of the devices. To end this summary highlights the major findings and contributions of this work. Initially it is necessary to say that the simulator device used was originally developed for operation with BJT devices and HBT. Therefore the starting point for this work has been adapting the code to ensure their proper functioning devices HEMT and implementation of the various sources of fluctuations study. Because of the need to optimize the use of available computational resources has been carried out a study of the efficiency of parallel simulator 3D and have proposed three alternatives for improvement. First there has been a comprehensive study of the efficiency gained from some of the settlement methods and techniques available for preconditioning solving systems of linear equations arising from the scattered discretization of the equations arrastre-difusión on both devices HEMT as other devices. This study has permitted the choice of settlement methods best suited to our particular problem, always bearing in mind the goal of minimizing the time computing. Secondly has been found that the phase resolution of linear equations implemented in the simulator consumed more than 90% of the total time simulation. Therefore this stage has been discussed in depth with the aim of seeking their party more expensive. It was found that a large portion of time spent was used in the conduct of factoring incomplete LU, and it has changed the code to reduce the influence of this time, achieving a significant increase in the efficiency of parallel simulator 3D device, both the resolution of the Poisson equation as in the resolution of the continuity equation for electrons. This is very important, since earlier to resolve the continuity equation electron there is a very significant decrease in the efficiency of the parallel process simulation. Thirdly has tried to take advantage, at the time of partition tetrahedral grid finite element, the current flow in the interior of these devices, and of course in other similar places, occurs in a single direction. Results have been presented d 8 and time fe9 satisfactory using the new proposal for partitioning, which improved to a small number of processors the times obtained using the partitioner METIS. It should be said that this proposal has not been fully developed, as the next step would be to adapt the code simulator for the full utilization of bulk grain parallelism inherent therein. This is one of our proposals for further work. Once optimized the simulator 3D parallel devices HEMT, this has been used in the analysis of the influence of fluctuating parameters inherent in the behavior of the devices. In this study we have used two different devices and have tried three different sources of fluctuations, the random variation of the composition of ternary materials which form the channel of the device, the influence of the discrete nature of atoms doping and random variation in loading interface between two borders of this device. The results show that, on the devices analyzed, the random distribution of doping within the layer delta-doping is the main source of fluctuations in the flow of HEMT, for example changes in the Indian content in the channel standard deviations leading to the current standard lower than the 30% of those caused by doping in delta-doping. Moreover, the impact of fluctuations due to load interfacial recess in the regions of the device is much less important than caused by the two other sources of fluctuations above. We compared the results obtained in conjunction with the two devices analyzed, we found that the influence of intrinsic parameter fluctuations is relatively small in the device PHEMT of 120 nm, obtaining maximum fluctuations in the flow of drenador of 18%. However, this value increases by reducing the size of the device. Thus, in the HEMT of 50 nm fluctuations in the flow of drenador have reached 70%, which can significantly affect the behavior of the devices HEMT high performance. Instead, the effect of fluctuations due to load in the interfacial region recess device is more important in the device PHEMT of 120 nm in the HEMT of 50 nm. Finally, in addition to the influence of intrinsic parameter fluctuations in the flow of drenador of devices, it also has studied the impact of fluctuations in the frequency of court. For both devices fluctuations intrinsic parameters affect severely the cutoff frequency. The device PHEMT of 120 nm has come to find an excursion from 32% in frequency values when compared with the case continued. In the HEMT of 50 nm influenced by fluctuations is more important, since it notes that gate voltages higher than -0.4 V, the impact of fluctuations always leads to a decrease in the frequency of court with respect to the value obtained in the case uniform, we get a reduction in the frequency of a 50% value considering continuing values of the parameters materials.

Author: Soto Búa Marcos.
Year: 2006.
University: SANTIAGO DE COMPOSTELA.
Place of defense: Facultad de Física.
Place of preparation: Facultad de Física.

Summary: The work reflected in this thesis is part of the problem of reconstruction of the phase of an electromagnetic wave from measures irradiance and focuses, in particular, the technique of reconstruction in the paraxial approximation based on the equation of Transportation Intensity (TSI). This equation derived league axial snapshot of the irradiance of a bundle with the variation of the transverse wave fronts. The significance of the TSI as a technical recovery phase is in the simplicity to be implemented simply from measures irradiance and in two orthogonal planes parallel to the optical axis, which makes it a versatile method, which applies in many branches of research in optics, which include the active and adaptive optics, the characterization of materials and Microscopy. The main objective of this work is to conduct a detailed study of this method to optimize their performance in different applications. The opening of finite devices that crosses the light beam, resulting in the presence of a pupil at the level of recovery. Accordingly, measures irradiance necessary to estimate the derivative axial not only be carried out within the pupil, but also around the edge or border, which is essential to regain the stage without ambigà ¼ ages. Moreover, the conservation of paraxialidad requires that the wave fronts are essentially flat. In most applications, this means that irradiance at the level of recovery can be considered approximately uniform. In this situation the TSI reported that the measures within the pupil relate to the curvature of the wavefront, while the measures at the border provide its normal derivative. Hence the name of wavefront sensors based on the TSI applied Optical Astronomy, which has been commonly called curvature sensors. This work provides answers to three questions that arise when working with sensors curvature. First, how to optimize the performance of sensor configurations curvature in the same routine. Second, how to improve the response of the sensor so that the stage has recovered more resolution. Thirdly, because of the increased difficulty in carrying out specific measures at the border to determine the weight of the information retrieved on the edge of the pupil relation to the rest of information obtained from measures in the interior. The report has been structured into five chapters. In the first one, it gives a historical review of the TSI as a technical recovery phase in various applications, reviews the main problems that arise when putting it into practice, the limitations of the solutions used so far and proposes new solutions which are the objectives of this research work. In the second chapter, is the estimate of the derivative axial irradiance within the pupil assuming uniform irradiance in terms of recovery, ie studies estimating the Laplacian of the stage. Specifically, it identifies the major sources of error measures the curvature of the wavefront and its variance is constructed on the basis of these factors and the axial position of irradiance levels. Lastly is the design of a method to optimize the performance of the sensor in relation to these measures, which is found in an illustrative example. The third chapter outlines the most common methods of obtaining information from the stage at the edge of the pupil, discusses the major constraints and calculates an expression for the error of the resulting normal phase in terms of these limiting factors the position and axial levels of irradiance. This information is the design of an optimization procedure of this kind of measures, which, as in the previous chapter, illustrated with an example. Once identified the limitations of traditional implementations of the TSI, in the fourth chapter proposes other sensor configurations pursuing the objective of improving their performance set the conditions of measurement. By 8 Finally, 7de in chapter fifth, addresses the problem of contour which is the TSI applied to a beam of light that has gone through a pupil, with the perspective to analyze the importance in the final outcome of the information retrieved on the edge in the same. The apparent complexity of the measures on the edge of the pupil justifies a study which extols its weight in the recovery phase compared with the measures in the interior. In conclusion, includes three appendices not only with support tools for the understanding of the chapters, but also with additional information geared more towards specific applications of the TSI. The first follows the TSI and is the version of the same particularizada beams limited to a breach in the level of recovery. The second is obtained expressions necessary to implement the procedure that takes place in this memory to optimize the sensor response curve, in applications where there is a time limitation that affect the detection of a finite number of photons. Finally, the third concerns the most common configuration of this technique recovery phase in the field of adaptive optics applied to Astronomy: configuration Roddier.

Author: DÍEZ PÉREZ ISMAEL.
Year: 2006.
University: BARCELONA.
Place of defense: FACULTAT DE QUÍMICAS.

Summary: This paper presents a study critical of the passivity of Faith through the use of advanced applications of Microscopias Probe Next. The main concepts of the discipline of electrochemical Semiconductor have been introduced in a simple way to make them accessible from a training electrochemistry. The final conclusions of this work leads to a diagram quantitative energy to the interface oxide / electrolyte. New methodologies developed in this thesis are working to extend quantitative study of the electronic transfer through a contact electrode / liquid.

Author: GARCÍA SÁNCHEZ CARLOS.
Year: 2006.
University: COMPLUTENSE DE MADRID.
Place of defense: FACULTAD CC. FÍSICAS.
Place of preparation: FACULTAD CC. FÍSICAS.

Summary: This thesis addresses the problem of optimization and parallelization of various applications in a new architectural scenario that has emerged with the introduction of new levels of parallelism within the current general purpose processors. SE has reviewed a series of algorithms great importance in the field of science in which the research group to which I belong has been working in recent years. Proposals previously studied are not entirely valid in the current architectural new scenario, so their review is very useful. Applications have been employed various fields either for the purpose of obtaining relevant conclusions and give a general work thus increased its interest practice. The applications in which they have worked from multiscale methods employed in resolving differences equations, wavelet transform incorporated in the standard understanding of images JPEG2000 and maps auto-organizativos used to classify tomography images. The pralelización proposed in the literature of such algorithms has been studied in other architectural context, where it was a priority to the efficient operation of local data. These strategies were based on the division of all input data that processed different processors. This scheme has many drawbacks in parallelization architecture GTS h as shown in this paper. Our alternative proposal proposes a division of labor that gives better results from the point of view of performance. We have also studied the improvement produced at the farm level parallelism of the data, incorporating new schemes vectorization all the applications under study. The improvements have been quite significant in all cases. And finally has deepened in the interaction of both optimizations, experiencing a substantial increase in profits to be gained in applying separately.

Author: Burriel López Mónica.
Year: 2006.
University: AUTÓNOMA DE BARCELONA.
Place of defense: Instituto de Ciencia de Materiales de Barcelona.
Place of preparation: Instituto de Ciencia de Materiales de Barcelona.

Summary: In recent years there has been a growing interest in the study of the compound La2NiO4 + d, due to its properties as driver mixed iónico-electrónico, which make suitable for use in electrochemical devices, such as cathode for oxide fuel cells solid intermediate temperatures (IT-SOFC), or permeation membranes for gas sensors. The structure of phase La2NiO4 + d consists of sheets of LaNiO3, type perovskita, alternating with sheets of LaO type sodium chloride, which can be incorporated oxygen sobreestequiométrico. This laminar structure is responsible for the anisotropy in the properties of La2NiO4 + d, resulting in an ionic conductivity and electronics which is between two and three orders of magnitude higher along the ab plane, compared with the c axis direction . This work consists in the study, from a fundamental point of view, thin films epitaxiales of La2NiO4 + d oriented along the axis cy grown by the technique of phase chemical vapor deposition of organometallic precursors pulsed injection (PI-MOCVD) on different substrates, with the aim of gaining a better understanding of the microstructural characteristics, their variation with stress and the influence of strain on the transport properties at elevated temperature. In addition, growth epitaxial allows measuring the properties of the films of La2NiO4 + d in two perpendicular directions, obtaining a direct measure of the anisotropy of the material. The La2NiO4 + d is the first member (n = 1) of the family Ruddlesden-Popper Lan +1 NinO3n +1, in which each member of the structure is formed by a number n block perovskita LaNiO3 alternating between blocks LaO type sodium chloride . It has also tried to deposit films oriented along the c axis of the members n = 2, 3 and 8, and has studied the variation of transport properties along the series Lan +1 NinO3n +1. The thesis is an introduction to the drivers mixed iónicos-electrónicos (MIEC) and cathodes for fuel cells, solid oxide (SOFC), as an application of the material La2NiO4 + d. It describes the most important properties of phase La2NiO4 + d, and members n = 2, 3 and 8 of the family Lan +1 NinO3n +1, as well as the state of the art for the preparation of thin films of these materials. Here we describe the technique of phase chemical vapor deposition of organometallic precursors pulsed injection (PI-MOCVD), accompanied by a detailed description of the parameters of selected deposit, and the team PI-MOCVD used. It also describes the techniques used in the characterization of thin films of Lan +1 NinO3n +1. Subsequently describes the reservoir parameters optimized for the deposition of films epitaxiales of La2NiO4 + d and there is a structural characterization, morphological and microstructural depending on the thickness of films, the material used and the temperature. Also detailed and describes conductivity total films epitaxiales of different thickness measurement. For these films have been measured, in addition, the properties for the exchange and dissemination of oxygen using two different techniques: the technical exchange and isotope technique relaxation of the conductivity. The results of these actions are discussed in terms of microstructure of the films. Finally, the study has been completed outlining the initial results of deposition of other family members Ruddlesden-Popper. The evolution of the total transport properties of the thin films of Lan +1 NinO3n +1 have been linked to the number of blades kind perovskita n.

Author: García Maraver Rocío.
Year: 2006.
University: AUTÓNOMA DE BARCELONA.
Place of defense: Facultat de Ciències.
Place of preparation: Grup d' Ã’ptica.

Summary: In this thesis deals with the processing of quantum information in quantum optical systems. The work focuses on the domain of quantum electrodynamics in cavities (cavity-QED) where the electromagnetic field formed by a few photons are confined to a cavity consisting of two mirrors high quality aligned so that it is possible to confine the resonant modes during times high enough so that the interaction luz-materia could be relevant. In cavity-QED can reduce interaction luz-materia the simplest case: the model Jaynes-Cummings, where a few atoms can interact with a single mode radiation confined in a cavity. Typically, the quantum system consists of the quantum states of atoms and the electromagnetic field, for example: the number of photons for each polarization. In this context, and considering three-tier systems atomic propose some models to make quantum engineering in cavity-QED. On the one hand, we propose the realization of a quantum logic gate for two-phase quantum pulses of light into orthogonal polarization. Also, considering statements of the field of radiation in a coherent state or semi is possible to create states of photons intertwined in polarization by implementing the stage door. Moreover, we propose a new mechanism to create pairs of photons intertwined, consisting of a three-level atom interacting, in turn, means confined in two cavities. This latest proposal has a great interest in its potential application to quantum cryptography. The study of the dynamics of the proposed models has been conducted by the formulations: density matrix, Schrödinger equation and the method of quantum leaps. These methods allow realistic results as it incorporates the presence of disipativos processes, we parameterized with the current value of the experiments cavity-QED in regimes optical and microwave.