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1
MONTI, ANDREA MAURIZIO. « Point defects in quartz : Role in trapping and luminescence ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2021. http://hdl.handle.net/10281/311082.
Texte intégralRésumé :
In questo lavoro di tesi sono state studiate le proprietà di intrappolamento e luminescenza dei difetti di punto nel quarzo. Tali proprietà sono usate in dosimetria retrospettiva al fine di valutare età archeologiche di reperti ceramici, età geologiche di sedimenti e radiazioni assorbite in casi di incidenti nucleari. Lo studio vuole fare chiarezza sui meccanismi specifici che governano tali proprietà nel quarzo. Nonostante il materiale sia arcinoto e già esistano applicazioni di questo materiale nei campi citati, queste ultime si basano su metodi empirici ed una teoria che possa spiegare e prevedere nel dettaglio le emissioni del quarzo è ancora incompleta.
Per fare ciò, sono state sfruttate sia tecniche di luminescenza indotte, direttamente o indirettamente, da radiazioni ionizzanti quali termoluminescenza (TL) e radioluminescenza (RL), sia una tecnica che studia i difetti paramagnetici, o in generale elettroni non accoppiati, ovvero la risonanza paramagnetica elettronica (EPR). TL e RL infatti non sono in grado da sole di poter identificare quali difetti siano responsabili delle emissioni del quarzo, ma è possibile cercare correlazioni usando tecniche che invece possono osservare direttamente tali difetti, come appunto la tecnica EPR. Correlando dati di TL ed EPR è stato possibile identificare impurezze di germanio con elettroni intrappolati, in particolare le trappole per elettroni [GeO4]- e [GeO4/Li+]0, come responsabili di emissioni di TL, i cosiddetti picchi a 110 °C e 375 °C. Nel corso dello studio è stato inoltre possibile individuare un'anomalia nella stabilità termica di uno di questi centri germanio, responsabile per il picco a 110 °C, confermando comunque la correlazione tra i due segnali ma sollevando nuove possibili criticità nelle applicazioni a fini di datazione e dosimetria.
Tramite gli studi EPR è stato inoltre possibile individuare nuovi centri paramagnetici mai riportati in letteratura e ne è stata caratterizzata la stabilità termica. Uno di essi è stato assegnato a un centro compensato con idrogeno interstiziale, mentre gli altri ancora necessitano una precisa assegnazione. È stata inoltre studiata la stabilità termica di centri legati a impurezze di titanio e alluminio al fine di cercare possibili correlazioni con proprietà di luminescenza. Delle possibilità sono state proposte, ma sono necessari ulteriori studi riguardo questo specifico punto.
Tramite RL e TL è stato mostrato inoltre come le lunghezze d'onda di emissione del quarzo siano molto dipendenti dal tipo di campione studiato e dalla sua storia termica. In particolare, tramite TL risolta in lunghezza d'onda è stato possibile mostrare come le proprietà dei campioni studiati non siano in accordo con alcuni modelli teorici pubblicati in letteratura. Lo studio ha consentito di proporre un'alternativa, seppur finora come modello qualitativo. Tale proposta sostiene che possano esistere correlazioni spaziali tra diversi difetti di punto nel quarzo, consentendo ricombinazioni specifiche senza l'ausilio delle bande di conduzione e valenza del materiale.
Benché lo studio sia ben lontano dall'aver trovato una descrizione completa nei comportamenti del quarzo, nuovi importanti tasselli sono stati aggiunti ai decenni di studi pubblicati, avvicinando la comunità scientifica al traguardo finale della comprensione dei processi di luminescenza di questo materiale.In this thesis work, the trapping and luminescence properties of point defects in quartz have been studied. Such properties are used in retrospective dosimetry in order to evaluate the age of archaeological artefacts, the age of geological sediments and the absorbed radiation in the event of nuclear accidents. The study aims at clarifying the specific mechanisms that rule such properties in quartz. Despite being quartz a well-known material and many applications in the aforementioned fields already existing, these are based on empirical methods and a theory that can explain and predict the emissions in quartz in a detailed way is still incomplete. To do so, two luminescence techniques are used, both induced, directly or indirectly, by ionizing radiation such as thermoluminescence (TL) and radioluminescence (RL), and a technique to study paramagnetic defects, or in general unpaired electrons, that is electron paramagnetic resonance (EPR). In fact, TL and RL alone are not enough to directly identify the defects that are responsible for such emissions, but it is possible to try to correlate their data with other techniques that can directly observe such defects, such as EPR. By correlating TL and EPR data, germanium related centres with trapped electrons, specifically [GeO4]- and [GeO4/Li+]0, have been identified as responsible for the TL emissions known as the peaks at 110 °C and 375 °C. At the same time, it was also possible to identify an anomaly in the thermal stability of one of these germanium centres, responsible for the 110 °C peak, confirming the correlation of the two signals, TL and EPR, but also raising new potential critical issues in the applications for dating and dosimetry. Through EPR studies, new unreported paramagnetic centres have been identified and their thermal stability has been characterized. One of them has been assigned to a centre compensated by interstitial hydrogen, while the others are still lacking a precise labelling. The thermal stability of titanium and aluminium related centres has also been studied, in search of possible correlations with luminescence properties. Some proposals have been advanced, but further studies are needed for this last specific point. Through RL and TL, it has been shown how the emission wavelengths in quartz are very sample dependent and how they are influenced by the thermal history of the studied sample. Specifically, through wavelength resolved TL it was possible to show how the properties of the studied samples do not agree with some published theoretical models. The study was able to propose an alternative, although so far just at a qualitative level. Such proposal claims that there may be spatial correlations between point defects in quartz, allowing specific direct recombination with no passage in the conduction and valence bands of the material. Despite this study is far from having found a complete description of quartz behaviour, new important steps have been added to the huge specific literature, contributing to a deeper comprehension of the luminescence properties of this material.
2
Gabrytė, Eglė. « Komunikacijos priemonės radijo stotyje Žinių radijas ». Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2006~D_20110709_151349-80086.
Texte intégralRésumé :
Magistro darbo objektas – „Žinių radijo“ komunikacijos priemonės. Darbo tikslas – ištirti, ar „Žinių radijo“ naudojamos komunikacijos priemonės yra efektyvios ir numatyti efektyvumą užtikrinančias priemones. Pagrindiniai darbo uždaviniai: išsiaiškinti, kokią reikšmę „Žinių radijas“ skiria komunikacijai su tikslinėmis publikomis; išanalizuoti, kokie naudojamos komunikacijos tikslai ir politika; ištirti, ar naudojamomis komunikacijos priemonės pasiekiama tikslinė „Žinių radijo“ auditorija; išsiaiškinti, kurios tiriamoje radijo stotyje naudojamos komunikacijos priemonės yra efektyviausios. Naudojant kokybinio ir kiekybinio tyrimo metodus, prieita prie išvados, kad „Žinių radijo“ naudojamos komunikacijos priemonės nėra efektyvios. Atlikus kokybinį tyrimą, paaiškėjo, kad nuo vadovo priklauso ne tik komunikacijai skiriamas dėmesys, pasirenkamos komunikacijos priemonės, bet ir pati komunikacijos strategija. Kokybinio tyrimo rezultatai leidžia daryti išvadą, jog radijas skiria dėmesio išorinei komunikacijai, tačiau nepakankamai. Pagrindinės to priežastys – žmonių trūkumas bei lėšų stygius. „Žinių radijas“ vis dar neturi savireklamos specialisto, todėl dažnai jo funkcijas atlieka reklamos skyrius ar net pats „Žinių radijo“ vadovas. Dabartinė „Žinių radijo“ komunikacijos politika labiau nukreipta į įmonių vadovus – jie kur kas daugiau žino apie „Žinių radiją“ (žino apie pasikeitusį logotipą, bei atnaujintą tinklelį, dažniau girdi cituojamą „Žinių radiją“). Efektyviais komunikacijos... [toliau žr. visą tekstą]The aim of this work was to view it not as the means of communication but the organization seeking its profit. The main task was to analyze the main possible means of communication on radio stations and their effectiveness on the radio station „News Radio“. After having interviewed the representatives of „News Radio“ (during a qualitative analysis) it became clear that the aims of communication depends on a season. In autumn after presenting a new network self-advertisement strategy is usually aimed at advertising of the program. In the middle of the season more attention is paid more attention is paid at supporting the image of „News Radio“. During a quantitative analysis which aim was to make surveys of the present means of communication and their effectiveness it became obvious that these means are ineffective. Therefore, we can make a conclusion that the present „News Radio“communication policy is targeted at the executives of enterprises. The effective communication channels should be considered those which reach the whole objective audience (the listeners of managing or non- managing duties). In this case those who were interviewed stated that the most information about „News Radio“ was received from its page on internet. Advertisement of 'NEWS Radio' is mostly seen in press.
3
Humbert, Jean. « Paralysie radiale idiopathique, au bras ». Bordeaux 2, 1997. http://www.theses.fr/1997BOR2M159.
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Girard, Jean-Yves. « Contribution a l'etude de la vascularisation de la tete radiale ». Nantes, 1993. http://www.theses.fr/1993NANT246M.
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DECOURT, CORREIA CECILIA. « Traitement des fractures de la tete radiale chez l'enfant par poinconnage percutane : travail des services de chirurgie infantile de l'hopital edouard herriot, pavillon t bis et de la clinique eugene andre, service du docteur kohler ». Lyon 1, 1994. http://www.theses.fr/1994LYO1M022.
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COSTA, Jackson Jonas Silva. « Soluções radiais e não radiais para a Equação de Hénon na bola unitária ». Universidade Federal de Campina Grande, 2010. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/1232.
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Brennan, James. « Experimental Investigation of Chevrons in Radial-Radial Swirlers ». University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1377871550.
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Vieira, Francisca Damiana. « NÃo existÃncia de autovalores do operador de Laplace-Beltrami em grÃficos radiais ». Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14017.
Texte intégralRésumé :
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoNeste trabalho estudamos o operador de Laplace-Beltrami definido em variedades Riemannianas. AlÃm do espectro de tal operador, apresentamos tambÃm algumas de suas propriedades, como o fato deste operador ser auto adjunto e nÃo negativo. Nosso objetivo principal consiste em analisar a existÃncia de autovalores para o operador de Laplace-Beltrami, sob determinadas condiÃÃes, em superfÃcies que sÃo grÃficos de funÃÃes radiais, definida sobre todo o plano, ou seja, superfÃcies nÃo compactas de revoluÃao. Esta dissertaÃÃo se baseia no artigo On the spectrum of the Laplace-Beltrami Operator on a Non-Compact Surface" de Takao Tayoshi ( Comm. By Kinjir^o Kunugi, M. J. A., Feb. 12,1971). Para realizaÃÃo desse trabalho foram introduzidos conceitos bÃsicos de anÃlise funcional com destaque para o estudo de espaÃos de Hilbert e a teoria espectral de operadores auto adjuntos, geometria riemanniana em superfÃcies e equaÃÃes diferenciais parciais, em particular resultados para operadores elÃpticos de segunda ordem. AlÃm disso, se fizeram necessÃrios alguns resultados de matemÃtica avanÃada.
In this work we study the Laplace-Beltrami operator defined on Riemannian manifolds. In addition to the spectrum of such an operator, we also present some of its properties, such as the fact that this operator is self-adjoint and non-negative. Our main goal is to analyze the existence of eigenvalues for the Laplace-Beltrami operator, under certain conditions, for exemple, surfaces that are complete graphs of radial functions, which is a revolution non-compact surfaces. This dissertation is based on the article "On the spectrum of the Laplace-Beltrami Operator on the Non-Compact Surface"of Takao Tayoshi(Comm. By Kinjiro Kunugi, MJA, Feb. 12, 1971). To perform this work were introduced basics concepts of functional analysis, with emphasis on the study of Hilbert spaces and the spectral theory of self-adjoint operators, Riemannian Geometry in surfaces and Partial Differential Equations, in particular results for elliptic operators of second order.In addition, were needed some results for advanced mathematics.
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Futoryanova, Valentina. « Radial-turbine mistuning ». Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/270194.
Texte intégralRésumé :
One of the common failure modes of the diesel engine turbochargers is high-cycle fatigue of the turbine-wheel blades. Mistuning of the blades due to the casting process is believed to contribute to this failure mode. A laser vibrometer is used to characterize mistuning for a population of turbine wheels through the analysis of the blade-response to piezo-speaker induced noise. The turbine-wheel design under investigation is radial and is typically used in 6-12L diesel engine applications. FRFs and resonance frequencies are reviewed and summarized. The study includes test results for a paddle wheel that represents a perfectly tuned system and acts as a reference. A discrete mass-spring model is developed for the paddle wheel and the model suitability is tested against measured data. Density randomization is applied to model mistuning in the turbine wheels. Frequency mistuning and relative amplitude modelling for blade modes is found in good agreement with the data, however the mass-spring model over-predicts amplitude-amplification factors for a population of radial-turbine wheels, especially with regard to hub-dominant modes. A continuous twisted-blade model is developed in Matlab using finite-element techniques. Experimental data is shown to have good agreement with the twisted-blade model. Whitehead’s maximum amplitude-amplification prediction using RMS value for a tuned amplitude value is calculated, and the turbine-wheel response is found to fit within the theoretical limit. Different mistuning patterns are studied using the twisted-blade model. Maximum and minimum response patterns are identified and recommended.
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Zoric, Branislav. « Modelling the influence of stocking on longitudinal and radial variation in wood properties of Pinus radiata on a warm Northland site ». Thesis, University of Canterbury. School of Forestry, 2009. http://hdl.handle.net/10092/2564.
Texte intégralRésumé :
The objective of this study was to determine how final stocking influences tree growth and radial and longitudinal variation in wood properties at a Pinus radiata D. Don plantation located at one of the warmest forest sites in New Zealand, Forsyth Downs forest in Northland. This thesis addressed both the effect of stocking on stand basal area, height, diameter and branch diameter and the effect of stocking on wood properties microfibril angle (MFA), module of elasticity and density. Finally, how ring width influences wood properties and whether this variable accounts for the treatment effects was investigated.
Stocking, height and ring number and all interactions between these variables significantly affected ring width. Ring width by itself was significant as a predictor of density, but when it was combined with other class level variables it was insignificant (i.e. does not account for treatment effects), and it did not add anything to a model with only class effects. There was a significant impact of ring number on density while ring width was insignificant in the same model.
MFA was significantly affected by ring width, height and ring number in the tree, and all interactions, apart from the three way interaction, but not by stocking. Ring width was significant in the MFA model both by itself and when it was combined with other variables. Ring width accounted for the stocking effect.
The best model of MOE included the class level effects of stocking, height and ring number within the tree, and all interactions between these variables, and ring width, as a continuous variable. While there was a significant effect between stockings this was relatively weak compared to the other main effects. Ring width largely accounted for the effect of stocking, but not that of ring number, or height.
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Rallabhandi, Aniketh S. « Experimental Investigation of the Reacting Flowfield of a Radial-Radial Swirler ». University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin154409847287965.
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Vilamiu, Raphael Gustavo d'Almeida. « Generalização da decomposição por EMD para grafos e sua aplicação à dispersão geográfica da dengue ». [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/306715.
Texte intégralRésumé :
Orientador: Wilson Castro Ferreira JuniorTese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática, Estatística e Computação Científica
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Resumo: Nesta tese, desenvolvemos uma técnica para gerar grafos à partir de conjuntos de séries temporais considerando a correlação entre estas e uma extensão do Método de Decomposição Empírica (EMD) para grafos (GEMD). Tal trabalho se justifica pelo fato de que uma grande gama de sinais formados por conjuntos de séries temporais não possuem uma localização bem definida em nenhum espaço n-dimensional. Desta forma, as relações entre as séries temporais só são satisfatoriamente representadas com o uso de grafos. Contudo, o desenvolvimento do GEMD é dependente do uso de algum método de interpolação em grafos. Tais métodos são escassos e não produzem propriedades satisfatórias para o uso no GEMD. Para esta finalidade, estendemos a interpolação por Funções de Base Radial (RBF) em Grafos (GRBF), onde a norma euclidiana no cálculo da matriz de interpolação por RBF é substituída pela norma induzida pelo grafo. Testes numéricos sugerem que a extensão possui boas propriedades de convergência e uma técnica é desenvolvida para garantir a existência e unicidade da solução. Finalmente, aplicamos o GEMD em um conjunto de dados de incidência de Dengue Hemorrágica na Tailândia. Os modos intrínsecos encontrados desta forma não apresentam nenhuma onda viajante emanando de nenhuma das províncias, contrastando com o resultado utilizando o EMD original [5]. Além disso, os períodos médios dos modos intrínsecos de [5] são claramente distintos dos encontrados pela decomposição por GEMD
Abstract: In this thesis, we developed a technique to generate a graph from a set of temporal series, which are then decomposed trough an extension of the Empirical Mode Decomposition (EMD) on Graphs (GEMD) created by us. This procedure is justified by the fact that a huge amount of signals cannot be properly localized on an n-dimensional space which can only be properly represented by a graph. The development of the GEMD is dependent on some graph interpolation method. Such methods are scarce in the literature and do not have the necessary properties to accomplish the GEMD decomposition. For this goal, we extend the Radial Basis Functions (RBF) interpolation to graphs (GRBF), where the euclidean norm used in the calculation of the RBF interpolation matrix is substituted by a graph induced norm. Numerical tests suggests that GRBF have good convergence properties and we present a technique which guarantees the existence and uniqueness of the solution. We finally apply the GEMD decomposition to a data set of Dengue Hemorrhagic Fever incidence in Thailand. The intrinsic modes found in this way do not show any traveling wave emanating from any of the provinces, contrasting with the results found using the original EMD [5]. Moreover, the mean period for the intrinsic modes in [5] are clearly diverse of those found by GEMD decomposition
Doutorado
Doutor em Matemática Aplicada
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Delavoix, Philippe. « Traitement des fractures de la tête radiale de l'adulte par rééducation fonctionnelle précoce : à propos de 60 cas ». Bordeaux 2, 1993. http://www.theses.fr/1993BOR2M157.
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Aljure, osorio Alejandro. « A contribution to 1D Modeling of Diesel Sprays and Combustion ». Thesis, Ecole centrale de Nantes, 2019. http://www.theses.fr/2019ECDN0038.
Texte intégralRésumé :
Les moteurs diesel sont largement utilisés pour la propulsion automobile, grâce à leur rendement élevé. Les émissions polluantes les plus importantes des moteurs diesel sont les NOx et les particules (en combustion Dieselconventionnelle). Il est difficile de réduire et contrôler ces émissions parce que la diminution d’un polluant entraine l’augmentation de l’autre. Une voie est la combustion Diesel LTC (Combustion à basse température) qui peut réduireces deux polluants, mais d’autres polluants apparaissent alors, comme CO et HC. Une façon d’arriver à desconditions LTC est l’utilisation de l’injection multiple (pilote/main, split injection, etc.). La caractérisation de cesinjections multiples est particulièrement complexe, en raison des interactions entre les différentes injections.Cette thèse a pour but de réaliser un modèle 1D de spray qui peut simuler l’injection multiple et la combustioncorrespondante dans un moteur diesel de type automobile, suite à la thèse de G. Ma soutenue au LHEEA en 2013,qui a développé un modèle de combustion basé sur le modèle de spray 1D eulérien de Musculus et Kattke (sprayinerte). Une comparaison de ce modèle avec un modèle lagrangien (Hiroyasu, Poetsch), qui a un traitement pseudo2D pour le spray de carburant, est menée pour évaluer les différences entre les approches et déterminer l’approche lamieux adaptée aux cas envisagés.L’interaction du spray avec une paroi, essentielle pour modéliser les conditions dans un moteur automobile faitégalement l’objet d’une étude bibliographique et de premières tentatives de modélisation. Une modélisation pseudo-2D pour le modèle Eulérien est faite pour améliorer le calcul du dégagement de chaleur et de délai d’inflammation. Lavalidation de ces différentes évolutions est faite en confrontant les résultats du modèle avec des résultatsexpérimentaux obtenus sur la base de données de l’ECN (Engine Combustion Network), mais aussi avec des relevéseffectués par des autres auteurs. Des développements spécifiques sont également introduits pour traiter le casd’injection multiple et l’injection dans une chambre de combustion à géométrie variable (le système piston-cylindre)Diesel engines are largely used in automotive propulsion due to their elevated efficiency. The most important pollutant emissions of diesel engines are NOx and particulate matter (in the case of conventional Diesel combustion). It is difficult to reduce and control these emissions because reducing one pollutant emission increases the other one. One way to try to achieve reduction in both pollutant emissions is called LTC (Low Temperature Combustion), which can reduce these two pollutants, but other pollutant emissions appear, as CO and HC. One way to achieve LTC conditions is using multiple injections (pilot/main, split injection, etc.). Modeling these injections is particularly complex, mainly due to their interactions.The objective of this thesis is to make a 1D spray model that can simulate multiple injections and the correspondingcombustion in an automobile diesel engine, continuing the work of G. Ma in his thesis defended at LHEEA in 2013,which developed a combustion model based in the 1D Eulerian spray of Musculus and Kattke (inert spray). Acomparison is made of this model and a Lagrangian model (Hiroyasu, Poetsch), which has a pseudo-2D treatment ofthe fuel spray, to evaluate the differences between the approaches and determine the best one suited for the foreseencases.The spray-wall interaction, essential to model the conditions inside an automotive engine, is subject to a bibliographyreview and coarse modeling. A pseudo-2D modeling for the Eulerian model is made, to improve the heat release rateand ignition delay calculation. The validation of these different evolutions is made by comparing the model results withexperimental results obtained from the ECN (Engine Combustion Network) data base, and also with data obtainedfrom the TSM test engines. Specific developments are also introduced to treat the multiple injection case and injectionin a variable geometry combustion chamber (the piston-cylinder system)
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Sayer, Min-hee Shin. « Evolution of radial force balance and radial transport over L-H transition ». Thesis, Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/45911.
Texte intégralRésumé :
Understanding of plasma confinement modes is an essential component in development of a fusion reactor. Plasma confinement directly relates to performance of a fusion reactor in terms of energy replacement time requirements on other design parameters. Although a variety of levels of confinement have been achieved under different operating conditions in tokamaks, tokamak confinement is generally identified as being either Low (L-mode--poor confinement) or High (H-mode--good confinement)
In operation of a tokamak experiment, the plasma confinement condition generally changes from L-mode to H-mode over a few hundred milliseconds, sometimes quite sharply. Such a difference in transition period seems to be largely due to operating conditions of the plasma. Comparison of experimental data exhibits various distinctions between confinement modes. One noteworthy distinction between confinement modes is development of steep density and temperature gradients of electrons and ions in the plasma edge region of High confinement, H-modes, relative to Low-confinement, L-modes.
The fundamental reason for the change for L-mode to H-mode is not understood. Previous studies have suggested i) the development of reduced diffusive transport coefficients that require a steepening of the gradients in a localized region in the edge plasma, the "transport barrier" in H-mode confinement ii) the radial force balance between pressure gradient forces and electromagnetic (radial electric field and VxB) forces require radial particle fluxes to satisfy a pinch-diffusion relation. A recent study suggests that the major difference between L-mode and H-mode are associated with the electromagnetic forces in the "pinch velocity" and the pressure gradient, not in the diffusion coefficients that multiplies the pressure gradient.
The research will examine in detail the time evolution of the radial force balance and the particle and energy transport during the L-H transition. For the analysis, DIII-D shot #118897 is selected for transition between L- and H-mode confinements. Plasma conditions in L-mode, near the L-H transition and following the transition are selected for analysis of various parameter profiles.
The initial analysis will be based on the four principal equations for plasma: particle balance, momentum balance, force balance and heat conduction. Based on these equations, specific equations have been derived: toroidal and radial momentum balances, diffusion coefficient, pinch velocity and heat conduction relation for calculation of parameters. The analysis of these equations, using the measured data, will establish how various terms in the radial force balance (radial electric field, VXB (electromagnetic) force, and pressure gradient) and the diffusive transport coefficients evolve over the confinement mode transition.
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Ribak, Samuel. « Tratamento da pseudoartrose do escafoide = estudo comparativo entre o uso do exerto ósseo da extremidade distal do rádio vascularizado e não vascularizado ». [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/311306.
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Orientador: Maurício EtchebehereTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Avaliaram-se os aspectos clínicos, funcionais e radiográficos de 86 pacientes portadores de pseudoartroses do escafoide. Comparam-se 46 pacientes submetidos à técnica de enxerto ósseo vascularizado dorsal do rádio distal, baseado na artéria suprarretinacular intercompartimental 1,2* (Grupo I), e 40 pacientes submetidos à cirurgia pela técnica de enxerto ósseo convencional não vascularizado da mesma região, rádio distal (Grupo II), objetivando definir o melhor procedimento quanto à consolidação e função. A amostra foi composta por 25 pseudoartroses no terço médio e 21 no polo proximal nos pacientes do Grupo I, e 22 no terço médio, duas no polo distal e 16 no polo proximal nos pacientes do Grupo II. No transoperatório, 30 escafoides foram considerados não vascularizados nos pacientes do Grupo I, e 20 nos pacientes do Grupo II. A estabilização do escafóide foi realizada por três fios de Kirschner e, no pós-operatório, todos os pacientes foram submetidos à imobilização com tala gessada antebraquiopalmar por quatro semanas. O tempo de seguimento médio pósoperatório foi de 24.4 meses (Grupo I), e de 21.7 meses (Grupo II). Conseguiu-se consolidação de 89.1% nos pacientes do Grupo I e tempo médio de consolidação de 9.7 semanas. Nos pacientes do Grupo II, houve consolidação em 72.5%, com tempo médio de 12 semanas. Os resultados funcionais do Grupo I foram satisfatórios em 72% dos pacientes e 57,5% no Grupo II. Concluímos que a técnica de enxerto ósseo vascularizado apresenta, quanto ao índice de consolidação e função, resultados superioresaos do procedimento não vascularizado, sendo mais eficiente quando a condição do polo proximal do escafoide é esclerótica
Abstract: The clinical, functional and radiographic aspects of 86 patients presenting with scaphoid nonunion were evaluated in this study. Forty-six patients undergoing the technique of vascularized bone graft from the dorsal distal radius, based on the 1, 2 intercompartmental supraretinacular artery (Group I), and 40 patients undergoing the technique of usual nonvascularized bone graft of the same area (distal radius) (Group II), are compared with the purpose of determining the best procedure concerning healing and function. Our sample comprised nonunions in 25 middle-third and 21 proximal-pole patients (Group I), and in 22 middlethird, 2 distal-pole, and 16 proximal-pole patients (Group II). Transoperatively, 30 scaphoids in Group I patients and 20 in Group II patients were considered sclerotic. Scaphoid stabilization was achieved with three K-wires and, postoperatively, and immobilization consisted of a short-arm cast for all patients for four weeks. The average postoperative follow-up time was 24.4 months for Group I, and 21.7 months for Group II. Healing was achieved in 89.1% of Group I patients, with an average healing time of 9.7 weeks. Within Group II, healing was achieved in 72.5% of patients, with an average healing time of 12 weeks. The functional results were satisfactory in 72% of Group I patients and 57.5% of Group II patients. We therefore conclude, from the healing and function indices, that the vascularized bone graft technique produces superior results than the nonvascularized bone graft procedure, being more efficient when the proximal pole of the scaphoid is sclerotic
Doutorado
Fisiopatologia Cirúrgica
Doutor em Ciências
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Nilsson, Martin. « Estimation of Radial Runout ». Thesis, Linköping University, Department of Electrical Engineering, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8744.
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The demands for ride comfort quality in today's long haulage trucks are constantly growing. A part of the ride comfort problems are represented by internal vibrations caused by rotating mechanical parts. This thesis work focus on the vibrations generated from radial runout on the wheels. These long haulage trucks travel long distances on smooth highways, with a constant speed of 90 km/h resulting in a 7 Hz oscillation. This frequency creates vibrations in the cab, which can be found annoying. To help out with the vibration diagnosis when a truck enters a mechanical workshop, this work studies methods for radial runout detection using the wheel speed sensors.
The main idea is to represent the varying radius signal with a sinusoid, where the calculations are based on Fourier series. The estimated radial runout value is then the amplitude of the sinusoid. In addition to the detection part, the work also present results regarding how the relative phase difference between two wheels with radial runout effects the lateral motion of the cab.
This thesis work was performed at Scania CV AB in Södertälje, Sweden and all measurements have been full scale experiments on real trucks.
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Webster, Christopher B. « Radial deblurring with FFTs ». Auburn, Ala., 2007. http://repo.lib.auburn.edu/07M%20Theses/WEBSTER_CHRISTOPHER_1.pdf.
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Du, Toit Wilna. « Radial basis function interpolation ». Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/2002.
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Thesis (MSc (Applied Mathematics))--Stellenbosch University, 2008.A popular method for interpolating multidimensional scattered data is using radial basis functions. In this thesis we present the basic theory of radial basis function interpolation and also regard the solvability and stability of the method. Solving the interpolant directly has a high computational cost for large datasets, hence using numerical methods to approximate the interpolant is necessary. We consider some recent numerical algorithms. Software to implement radial basis function interpolation and to display the 3D interpolants obtained, is developed. We present results obtained from using our implementation for radial basis functions on GIS and 3D face data as well as an image warping application.
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Henao, León Alexander Valencia. « A teia Browniana radial ». Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/45/45133/tde-08052012-232043/.
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Introduzimos uma familia de trajetorias aleatorias coalescentes com certo tipo de comportamento radial a qual chamaremos de Teia Poissoniana radial discreta. Mostramos que o limite fraco na escala difusiva desta familia e uma familia de trajetorias aleatorias coalescentes que chamaremos de Teia Browniana radial. Por m, caraterizamos o objeto limite como um mapeamento continuo da Teia Browniana restrita num subconjunto de R2.We introduce a family of coalescing random paths with certain kind of radial behavior. We call them the discrete radial Poisson Web. We show that under diusive scaling this family converges in distribution to a family of coalescing random paths which we call radial Brownian Web. Finally, we characterize the limiting object as a continuous mapping of the Brownian Web restricted to a subset of R2.
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Kubryk, Maxime. « Migration radiale dans les disques galactiques et applications à la Voie Lactée ». Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066599/document.
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Nous étudions la migration radiale des étoiles, et testons son impact sur l’évolution chimique de la Voie Lactée. Pour cela nous utilisons une simulation N-corps+SPH (Gadget-3) de galaxie fortement barrée, afin d’étudier la migration radiale induite par la barre. Nous examinons un nouveau mécanisme de migration radiale: une fraction des étoiles piégées à la corotation de la barre, se déplacent avec le rayon de corotation lorsque celui-ci va vers l’extérieur (quand la vitesse de rotation de la barre diminue, du fait de son évolution séculaire). Nous montrons que ce mécanisme affecte principalement les régions externes du disque, à condition que la corotation atteigne ces régions. Nous montrons également que ce mécanisme n’a pas d’effets dans la Voie Lactée, car les estimations observationnelles des caractéristiques de la barre, indiquent que la corotation est loin des zones externes. Nous analysons également la migration radiale dans cette simulation, afin de construire un modèle empirique de diffusion stellaire dans le disque, et nous incluons ce modèle dans un code semi-analytique d’évolution chimique de galaxie. Nous testons la validité de cette approche en vérifiant que les galaxies simulées N-corps+SPH et semi-analytique ont des propriétés morphologiques et chimiques similaires. Nous appliquons ensuite notre modèle à la Voie Lactée, en adaptant les paramètres du modèle. Puis, nous comparons les résultats obtenus avec un grand nombre d’observations concernant le voisinage solaire (relation âge-métallicité, distribution de métallicité, relation a/Fe vs Fe/H et la bimodalité disque mince - disque épais) , et les gradients radiaux d’abondanceWe study the radial migration of stars, and test its impact on the chemical evolution of the Milky Way. For this we use a simulation-body + SPH (Gadget-3) strongly barred galaxy to study the radial migration induced by the bar. We examine a new mechanism of radial migration: a fraction of stars trapped at corotation with the bar, move with the corotation radius when it goes outwards (when the rotational speed of the bar decreases, because of its secular evolution). We show that this mechanism affects mainly the outer regions of the disc, provided that the corotation reaches these regions. We also show that the mechanism has no effects in the Milky Way, as the observational estimates of the characteristics of the bar indicates that the corotation is not in the outer regions. We also analyze the radial migration in this simulation to construct an empirical model of diffusion in the stellar disk, and we include this model in a semi-analytic code of chemical evolution of galaxy. We test the validity of this approach by ensuring that the galaxies simulated with N-body + SPH and semi-analytic have similar morphological and chemical properties. We then apply our model to the Milky Way, by adapting the model parameters. Then, we compare the results obtained with a large number of observations on the solar neighborhood (age-metallicity relation, metallicity distribution, relationship O/Fe vs. Fe/H and bimodality thin disk - thick disk), and radial gradients of abundances
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Mkumbwa, Moses Hassan. « Simulation and geometrical optimization of radial and non-radial rotary sliding vane air compressors ». Thesis, University of Strathclyde, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321181.
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Samozino, Marie. « Voronoi Centred Radial Basis Functions ». Phd thesis, Université de Nice Sophia-Antipolis, 2007. http://tel.archives-ouvertes.fr/tel-00336379.
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Cette thèse s'inscrit dans la problématique de la reconstruction de surfaces à partir de nuages de points. Les récentes avancées faites dans le domaine de l'acquisition de formes 3D à l'aide de scanners donnent lieu à de nouveaux besoins en termes d'algorithmes de reconstruction. Il faut être capable de traiter de grands nuages de points bruités tout en donnant une représentation compacte de la surface reconstruite.La surface est reconstruite comme le niveau zéro d'une fonction. Représenter une surface implicitement en utilisant des fonctions de base radiales (Radial Basis Functions) est devenu une approche standard ces dix dernières années. Une problématique intéressante est la réduction du nombre de fonctions de base pour obtenir une représentation la plus compacte possible et réduire les temps d'évaluation.
Réduire le nombre de fonctions de base revient à réduire le nombre de points (centres) sur lesquels elles sont centrées. L'objectif que l'on s'est fixé consiste à sélectionner un "petit" ensemble de centres, les plus pertinents possible. Pour réduire le nombre de centres tout en gardant un maximum d'information, nous nous sommes affranchis de la correspondance entre centres des fonctions et points de donnée, qui est imposée dans la quasi-totalité des approches RBF. Au contraire, nous avons décidé de placer les centres sur l'axe médian de l'ensemble des points de donnée et de montrer que ce choix était approprié.
Pour cela, nous avons utilisé les outils donnés par la géométrie algorithmique et approximé l'axe médian par un sous-ensemble des sommets du diagramme de Voronoi des points de donnée. Nous avons aussi proposé deux approches différentes qui échantillonnent de manière appropriée l'axe médian pour adapter le niveau de détail de la surface reconstruite au budget de centres alloué par l'utilisateur.
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Samozino, Marie. « Voronoi Centered Radial Basis Functions ». Phd thesis, Université de Nice Sophia-Antipolis, 2007. http://tel.archives-ouvertes.fr/tel-00178274.
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Cette thèse s´inscrit dans la problématique de la reconstruction de surfaces à partir de nuages de points. Les récentes avancées faites dans le domaine de l´acquisition de formes 3D à l´aide de scanners donnent lieu à de nouveaux besoins en termes d´algorithmes de reconstruction. Il faut être capable de traiter de grands nuages de points bruités tout en donnant une représentation compacte de la surface reconstruite. La surface est reconstruite comme le niveau zéro d´une fonction. Représenter une surface implicitement en utilisant des fonctions de base radiales (Radial Basis Functions) est devenu une approche standard ces dix dernières années. Une problématique intéressante est la réduction du nombre de fonctions de base pour obtenir une représentation la plus compacte possible et réduire les temps d´évaluation. Réduire le nombre de fonctions de base revient à réduire le nombre de points (centres) sur lesquels elles sont centrées. L´objectif que l´on s´est fixé consiste à sélectionner un "petit" ensemble de centres, les plus pertinents possible. Pour réduire le nombre de centres tout en gardant un maximum d´information, nous nous sommes affranchis de la correspondance entre centres des fonctions et points de donnée, qui est imposée dans la quasi-totalité des approches RBF. Au contraire, nous avons décidé de placer les centres sur l´axe médian de l´ensemble des points de donnée et de montrer que ce choix était approprié. Pour cela, nous avons utilisé les outils donnés par la géométrie algorithmique et approximé l´axe médian par un sous-ensemble des sommets du diagramme de Voronoi des points de donnée. Nous avons aussi proposé deux approches diférentes qui échantillonnent de manière appropriée l´axe médian pour adapter le niveau de détail de la surface reconstruite au budget de centres alloué par l´utilisateur.
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Dale, Adrian Peter. « Radial, vaneless, turbocharger turbine performance ». Thesis, Imperial College London, 1990. http://hdl.handle.net/10044/1/11363.
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Galván, Oré Liliana. « Pensamiento radial y mapa mental ». Universidad Peruana de Ciencias Aplicadas - UPC, 2007. http://hdl.handle.net/10757/272403.
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Ho, Y. K. « Supersonic and subsonic radial jets ». Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378306.
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ALVES, CARLOS FREDERICO ESTRADA. « TRANSIENT SIMULATIONS ON RADIAL DIFUSORS ». PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 1998. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=19466@1.
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COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOREste trabalho apresenta o estudo do escoamento transiente em difusores radiais com fronteira móvel alimentados axialmente. O problema é resolvido acoplando-se a modelagem do fluido à dinâmica do movimento da palheta. Admite-se o comportamento Newtoniano para o fluido de trabalho (ar). O escoamento é considerado incompressível, laminar e isotérmico numa geometria axisimétrica. As equações de conservação são resolvidas pelo método dos volumes-finitos utilizando-se um código numérico comercial, o FLUENT, adaptado de modo a permitir que o posicionamento da fronteira móvel faça parte da solução do problema. Analise-se os casos de movimentação súbita imposta à palheta e de fluxo mássico de alimentação periódica. Resultados do comportamento temporal da força axial do fluido sobre a palheta são apresentados. Determina-se também o campo de geração de entropia para o escoamento bem como sua variação para diversos instantes de tempo.
This work presents the study of unsteady flow in a axially fed radial flow between parallel disks on a situation in which the frontal disk can move. The problem is solved coupling the fluid flow modeling and the valve dynamics movement. The fluid (air) is assumed to have a Newtonian behavior. The flow is incompressible, laminar and isothermal in an axisymmetric geometry. The governing equations are solved by finite volume methodology using a commercial software, FLUENT, which have been modified to admit boundary movement as part of the solution. The flow characteristics presented herein relate to situations where: I. the frontal disk is suddenly moved to a new location and ii. prescribed mass flux at the inlet orifice. Results for the behavior of the axial force in the frontal disk can be seen. Another important parameter analyzed is the entropy generation and its time variation.
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Schreiber, Christoph. « Inlet recirculation in radial compressors ». Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/270611.
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Deficient performances of turbocharger compressors inside turbo-charged engines limit the behaviour of the drive train. This problem has shifted the design space for compressors towards their performance at part-speed and low-flow conditions. The most dominant feature of these flow conditions is inlet recirculation. It causes a large portion of flow to be expelled through the rotor inlet, creating a blockage ring on the casing. While on the one hand, inlet recirculation is the main loss-source at low-speed and low-flow within centrifugal compressors, on the other hand, it also keeps the compressors functioning because it reduces incidence. This thesis aimed towards increasing the understanding of inlet recirculation, with the scope on improving the part-speed, low-flow performance of automotive turbocharger compressors. The phenomenon was investigated regarding its key features, the conditions at which it occurs and its impact on performance. Furthermore, a reduced order model was derived and the influence of the tip gap size as a design parameter was analysed. The research was carried out on an automotive turbocharger compressor which was investigated experimentally and numerically. Inlet recirculation is a phenomenon which takes place in the tip region of the rotor, extending far downstream and far upstream of the leading edge. The flow within the recirculation bubble features a strong positive swirl component, affecting the work input into the machine. The phenomenon is non-periodic in a time-averaged sense. An investigation of the rotor flow-field regarding inlet recirculation, carried out for the first time, revealed that the starting point of inlet recirculation is located far inside the rotor passage. An analysis based on mass, momentum and energy allowed the derivation of a low-order model to account for inlet recirculation in preliminary design. In the compressor map, inlet recirculation was present over 40% of the map width at low speeds. It maintained its presence with increasing rotor speed beyond the point where the inlet flow became transonic. The losses in the inlet recirculation zone were shown to be up to 35% of the total compressor loss at low speed. A loss analysis showed that inlet recirculation was the main loss source at low-flow conditions. The tip clearance study showed that the size and intensity of inlet recirculation was independent of the tip gap size. Efficiency gains due to reduced tip leakage were marginalised by the presence of inlet recirculation but the rotor maintained enhanced pressure rise capabilities for reduced tip gap sizes.
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Danielsson, Johan, et Karin Nykvist. « Mäns upplevelser av miktionsproblem och erektil dysfunktion efter radikal prostatektomi : En litteraturöversikt ». Thesis, Högskolan Dalarna, Omvårdnad, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:du-10524.
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Syfte: Syftet var att beskriva hur män upplever att de påverkats av miktionsproblem och erektil dysfunktion efter radikal prostatektomi. Metod: Examensarbetet utfördes som en litteraturöversikt med tio vetenskapliga studier. Resultat: Upplevelsen av förlorad kontroll vid miktionsproblem var det som främst påverkade männen samt medförde att det sociala livet blev lidande. Männen beskrev hur de var tvungna att planera inför olika sociala tillställningar, vilket upplevdes som stressande och ångestfyllt. Det framkom också att männen oroade sig för urinläckage, stark odör och upplevde möten med oförstående människor som frustrerande. Erektil dysfunktion var den vanligaste komplikationen efter behandling, men miktionsproblem var det som orsakade mest besvär. Det upplevdes som att männen förlorat sin självständighet. Det framkom även att erektil dysfunktion upplevdes av vissa män som den komplikation som gav störst besvär. Erektil dysfunktion påverkade männen och var mycket svårt att hantera. Det var svårt att finna en acceptans för att den erektila dysfunktion kunde vara bestående. Många av männen beskrev att en viktig del i deras liv förlorats, en del av deras maskulinitet. De kände sig ofullständiga och det fanns en rädsla för att förlora sin partner. Slutsats: Studier visar att erektil dysfunktion och miktionsproblem i samband med radikal prostatektomi ger upphov till stress, oro, ångest samt en känsla av ofullständighet.
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FRUSTAGLI, GIUSEPPE. « Exoplanets Characterization : from Ultra-short Period Planets to Ultra-hot Jupiters Atmospheres ». Doctoral thesis, Università degli Studi di Milano-Bicocca, 2021. http://hdl.handle.net/10281/311363.
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La scoperta di pianeti che orbitano intorno ad altre stelle è uno degli eventi più importanti nell'astrofisica galattica degli ultimi due decenni. Dalla scoperta del primo esopianeta nel 1995, il numero di esopianeti scoperti è cresciuto sempre più in fretta e attualmente conosciamo più di 4,000 pianeti, molto diversi per dimensioni e distanza dalla stella ospite e anche in fattori come temperatura, massa, densità.
La diversità degli esopianeti è un fattore chiave per comprendere la formazione dei sistemi planetari e in particolare la formazione del Sistema Solare e del nostro pianeta, la Terra. Questo è il motivo per cui la scienza osservativa degli esopianeti si sta concentrando su due diversi obiettivi: i) la caratterizzazione degli esopianeti, nel tentativo di determinare il raggio, la massa, la densità e la composizione degli oggetti osservati e ii) la caratterizzazione delle loro atmosfere, stabilendo gli elementi che l'atmosfera di un pianeta può supportare e i meccanismi che guidano i processi atmosferici.
Caratterizzazione degli Esopianeti
La fotometria, con il metodo dei transiti si è rivelato senza dubbio il metodo di scoperta di esopianeti con il maggior successo. La forza di questo metodo è il numero di parametri che possono essere ottenuti osservando il transito dei pianeti, soprattutto in combinazione con le osservazioni di velocità radiale (VR).
In questo contesto, uno dei gruppi più prolifici è il Consorzio GTO di HARPS-N, che sfrutta l'alta risoluzione e l'estrema stabilità dello spettrografo HARPS-N, installato al Telescopio Nazionale Galileo, per caratterizzare e scoprire esopianeti combinando il metodo dei transiti e quello delle velocità radiali. Come collaboratore di questo gruppo, ho studiato un pianeta candidato scoperto dalla Campagna 16 della missione K2, HD 80653 b, una super-Terra che transita davanti alla sua stella con un periodo orbitale molto breve, e ho usato le VR HARPS-N per caratterizzarlo, ottenendo la sua massa e definendone la densità. Il pianeta appartiene ad una particolare classe di esopianeti: i pianeti a periodo ultra-corto, oggetti che orbitano intorno alle loro stelle con periodi estremamente brevi, più piccoli di due raggi terrestri e con composizioni simili a quella terrestre.
Caratterizzazione di Atmosfere
I gioviani ultra-caldi sono laboratori eccellenti per lo studio delle atmosfere esoplanetarie. Il sodio, per la sua grande sezione d'urto e per il fatto che le sue righe spettrali principali si trovano nel range spettrale della maggior parte degli spettrografi, è l'elemento più studiato, ma lo studio di nuove righe spettrali è cominciato. Righe del ferro, del titanio, del magnesio, ma anche tracce di cromo, scandio e ittrio sono state trovate negli spettri di trasmissione ad alta risoluzione dei pianeti più caldi.
I due gioviani ultra-caldi KELT-9 b e KELT-20 b sono stati osservati dal programma atmosfere del gruppo italiano Global architecture of Planetary Systems (GAPS).
Come membro del gruppo ho potuto esplorare più in dettaglio il metodo della spettroscopia in transito, creando due diverse routine per la caratterizzazione delle atmosfere. Il primo metodo segue approcci già utilizzati in precedenza, ma è in grado di rilevare righe spettrali deboli come quelle del magnesio, sommandole nello spazio delle velocità. Usando questo approccio ho analizzato gli spettri ad alta risoluzione di KELT-9 b e KELT-20 b e ho ottenuto i loro spettri di trasmissione, rilevando un assorbimento significativo per Na, H, Fe e Mg I.
Il secondo metodo estrae gli spettri di trasmissione ad alta risoluzione e li cross-correla con modelli teorici di spettri di trasmissione. Analizzando gli spettri di KELT-20 b e utilizzando la cross-correlazione ho potuto confermare la presenza di Fe I, Fe II e Na I, trovate da analisi precedenti di altri gruppi di ricerca.The discovery of planets orbiting around stars other than the Sun is by far the most relevant event in the galactic astrophysics of the last two decades. Since the discovery of the first exoplanet in 1995, the number of exoplanets discovered grew fast and we currently know more than 4,000 exoplanets, very diverse in dimension and distance from parent stars and also in factors as temperature, mass, density. The diversity of exoplanets is a key factor to understand more about the formation of planetary systems and in particular the formation of the Solar System and our planet, the Earth. This is the reason why observational exoplanetary science is currently focusing on two different fields: i) the characterization of exoplanets, trying to determine the radius, the mass, the density and the bulk composition of the objects observed, and ii) the characterization of their atmospheres, establishing the elements that the atmosphere of a planet supports and the mechanisms that drive the atmospheric processes. Characterization of Exoplanets Photometry with the transit method has arguably been the most successful exoplanet discovery method to date. The method’s strength is the rich set of parameters that can be obtained from transiting planets, in particular in combination with RV observations. In this framework, one of the most prolific groups is the HARPS-N Guaranteed Time Observations (GTO) Consortium, that makes use of the high resolution (R = 115,000) and extreme stability of the HARPS-N spectrograph, installed on the Telescopio Nazionale Galileo (TNG), to characterize and discover exoplanets by combining transits and RV methods. As a collaborator of this group, I studied a candidate planet discovered by K2 Campaign 16, HD 80653 b, a super-Earth planet transiting the star on a short period orbit, and used HARPS-N RV data to characterize it, finding its mass and defining its bulk density. It belongs to a peculiar class of exoplanets: the Ultra-Short Period (USP) planets, objects that orbit their stars with extremely short periods, smaller than about 2 Earth Radii and compositions similar to that of the Earth. Characterization of Atmospheres Ultra-hot Jupiters are excellent laboratories for the study of exoplanetary atmospheres. Sodium, due to its large cross-section and to the fact it is in the wavelength range of most optical spectrographs, is the most studied element, but new interesting features begin to be analyzed. Lines of iron, titanium, magnesium, but also chromium, scandium and yttrium have been found in the high resolution transmission spectra of the hottest planets. The two ultra-hot Jupiters KELT-9 b and KELT-20 b were observed in the framework of the Global architecture of Planetary Systems (GAPS) Atmosphere program. I explored more in detail the transit spectroscopy method, creating two different routines for atmosphere characterization. The first routine follows previous approaches for high-resolution spectroscopy, but is able to detect weak spectral lines such as those of magnesium, by co-adding the lines in the velocities space. Using this procedure, I analyzed the high-resolution spectra of KELT-9 b and KELT-20 b, obtaining their transmission spectra and detecting significant absorption for Na, H, Fe and Mg I. The second routine extracts the high-resolution transmission spectra of exoplanets and cross-correlates them with theoretical transmission spectra models. I analyzed the high-resolution spectra of KELT-20 b and with the cross-correlation technique I confirmed previous detections of Fe I, Fe II, and Na I.
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SAINT-CAST, YANN-PIERRE. « Le syndrome du tunnel radial : a propos d'une sderie homogene et continue de 35 ans ». Angers, 1988. http://www.theses.fr/1988ANGE1082.
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Molteni, Jara María Cecilia. « Pertinencia cultural de los medios periodísticos nacionales en la región magallánica ». Tesis, Universidad de Chile, 2004. http://repositorio.uchile.cl/handle/2250/146103.
Texte intégralRésumé :
Seminario para optar a la Licenciatura en Comunicación SocialEste trabajo ha pretendido determinar la pertinencia cultural que la oferta informativa de los medios periodísticos nacionales presenta para los habitantes de la Región de Magallanes y Antártica Chilena, entendiendo como pertinencia cultural la manifestación de elementos sustantivos -en forma y contenido- que interpelan espontáneamente el modo de ser intrínseco de los sujetos que comparten una identidad. En la base, se encuentra la pregunta acerca del modo y rango en que los medios de comunicación nacionales están respondiendo a las necesidades de información de quienes no viven en Santiago y de cómo están participando en la preservación una homogenización artificial de la chilenidad en desmedro de la diversidad cultural del país. Debido a que el objetivo planteado sólo puede abordarse adecuadamente, mediante un estudio de orden cualitativo - ya que hablamos de consumo cultural e identidad- nos inscribimos en el enfoque epistemológico constructivista y utilizamos la técnica de los grupos de discusión. Analizamos los distintos relatos, desde las perspectivas de los hábitos informativos, preferencias por medios regionales o nacionales, necesidad y valoración de la información, modos en que se representa a la región magallánica en los medios nacionales, elementos culturales de la oferta noticiosa que comparten y se consideran propios. El resultado es significativo. Los magallánicos hacen una crítica profunda a los medios periodísticos nacionales, su calidad, contenidos y función social. A la vez, con excepción de escasos temas de orden político, económico y social, la información les resulta ajena, sin interés y culturalmente amenazante para el futuro del país.
34
Barrera, Mora Jose Felix Fernando. « On radical extensions and radical towers ». Diss., The University of Arizona, 1989. http://hdl.handle.net/10150/184833.
Texte intégralRésumé :
Let K/F be a separable extension. (i) If K = F(α) with αⁿ ∈ F for some n, K/F is said to be a radical extension. (ii) If there exists a sequence of fields F = F₀ ⊆ F₁ ⊆ ... ⊆ F(s) = K so that Fᵢ₊₁ = Fᵢ(αᵢ) with αᵢⁿ⁽ⁱ⁾ ∈ Fᵢ for some nᵢ ∈ N, charF ∧nᵢ for every i, and [Fᵢ₊₁ : Fᵢ] = nᵢ, K/F is said to be a radical tower. In the first part of this work, we present two theorems which give sufficient conditions for a field extension K/F to be radical. In the second part, we present results which provide conditions under which every subfield of a radical tower is also a radical tower.
35
Iskra, Wlodzimierz, Markus Müller et Ingrid Rotter. « Radial pattern of nuclear decay processes ». Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-32446.
Texte intégral
36
Weiß, Jörg. « Modellbildung und Simulation radial gekoppelter Rotoren ». Doctoral thesis, Universitätsbibliothek Chemnitz, 2008. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-200800347.
Texte intégralRésumé :
In Produktionsanlagen mit radial gekoppelten Rotoren wie beispielsweise Papier- und Druckmaschinen treten im höheren Drehzahlbereich störende Schwingungen auf. Der Entstehungsmechanismus der Schwingungen ist im nichtlinearen Verhalten der Kontaktstelle in enger Abstimmung mit der elastischen Lagerung der Walzen zu suchen. In dieser Arbeit wird aus maschinendynamischer Perspektive eine systematische Zusammenstellung von Rotormodellen entwickelt. Durch die Auswahl eines geeigneten Kontaktpartners wird das Modell vervollständigt. So kann ein Minimalmodell zur Untersuchung von Schwingungsphänomenen entwickelt werden. Fokussiert auf die Beschreibung der Koppelstelle werden geeignete Kontaktmodelle abgeleitet und vereinfachend betrachtet. Ein zur Unterstützung der theoretischen Analyse entworfener Versuchsstand diente zur Durchführung zahlreicher Versuche, die Parameterwerte für die Berechnungsmodelle lieferten und Schwingungsphänomene belegten. Die beschriebenen Modelle werden zur abstrahierenden numerischen Untersuchung ausgebaut und genutztPaper- and printing machines contain radially coupled rolls. Vibrational phenomena has been experienced at higher rotational speeds. The mechanisms leading to these vibrations are to be found in a nonlinear contact behavior between the roller pairs. A systematic approach to modelling of rolls has been developed from a dynamics point of view. Selecting an appropriate contacting roll model, the roller pair model has been completed. The so obtained minimum model is best situated to work out the influence of selected parameters on the dynamical behavior. With the focus set on the coupling of the rolls a simplified contact model is developed. Experimental data are obtained from a testing rig in support of the theoretical analyses. Parameter values have been calculated from experimental results. As a conclusion, the simulation models show the vibrational phenomena observed at the test rig
37
Rottler, Andreas [Verfasser]. « Investigation of Radial Metamaterials / Andreas Rottler ». München : Verlag Dr. Hut, 2013. http://d-nb.info/1037286847/34.
Texte intégral
38
Buhmann, Martin Dietrich. « Multivariable interpolation using radial basis functions ». Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315189.
Texte intégral
39
Sato, Kenji. « Blade row interaction in radial turbomachines ». Thesis, Durham University, 1999. http://etheses.dur.ac.uk/4349/.
Texte intégralRésumé :
A computational study has been performed to investigate the effects of blade row interaction on the performance of radial turbomachines, which was motivated by the need to improve our understanding of the blade row interaction phenomena for further improvement in the performance. High-speed centrifugal compressor stages with three settings of radial gap are configured and simulated using a three-dimensional Navier-Stokes flow method in order to investigate the impact of blade row interaction on stage efficiency. The performance predictions show that the efficiency deteriorates if the gap between blade rows is reduced to intensify blade row interaction, which is in contradiction to the general trend for stage axial compressors, hi the compressors tested, the wake chopping by diffuser vanes, which usually benefits efficiency in axial compressor stages, causes unfavourable wake compression through the diffuser passages to deteriorate the efficiency. Similarly, hydraulic turbine stages with three settings of radial gap are simulated numerically. A new three-dimensional Navier-Stokes flow method based upon the dual-time stepping technique combined with the pseudo-compressibility method has been developed for hydraulic flow simulations. This method is validated extensively with several test cases where analytical and experimental data are available, including a centrifugal pump case with blade row interaction. Some numerical tests are conducted to examine the dependency of the flow solutions on several numerical parameters, which serve to justify the sensitivity of the solutions. Then, the method is applied to performance predictions of the hydraulic turbine stages. The numerical performance predictions for the turbines show that, by reducing the radial gap, the loss generation in the nozzle increases, which has a decisive influence on stage efficiency. The blade surface boundary layer loss and wake flow mixing loss, enhanced with a higher level of flow velocity around blading and the potential flow disturbances, are responsible for the observed trend.
40
Bjorkhaug, M. « Flame acceleration in obstructed radial geometries ». Thesis, City University London, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374279.
Texte intégral
41
Banica, Marius Christian. « Noise prediction for a radial turbine ». Thesis, University of Cambridge, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.613305.
Texte intégral
42
Ortiz, Mauricio, Sabine Reffert, Trifon Trifonov, Andreas Quirrenbach, David S. Mitchell, Grzegorz Nowak, Esther Buenzli et al. « Precise radial velocities of giant stars ». EDP SCIENCES S A, 2016. http://hdl.handle.net/10150/622444.
Texte intégralRésumé :
Context. For over 12 yr, we have carried out a precise radial velocity (RV) survey of a sample of 373 G- and K-giant stars using the Hamilton Echelle Spectrograph at the Lick Observatory. There are, among others, a number of multiple planetary systems in our sample as well as several planetary candidates in stellar binaries. Aims. We aim at detecting and characterizing substellar and stellar companions to the giant star HD 59686 A (HR 2877, HIP 36616). Methods. We obtained high-precision RV measurements of the star HD 59686 A. By fitting a Keplerian model to the periodic changes in the RVs, we can assess the nature of companions in the system. To distinguish between RV variations that are due to non-radial pulsation or stellar spots, we used infrared RVs taken with the CRIRES spectrograph at the Very Large Telescope. Additionally, to characterize the system in more detail, we obtained high-resolution images with LMIRCam at the Large Binocular Telescope. Results. We report the probable discovery of a giant planet with a mass of m(p) sin i = 6.92(-0.24)(+0.18) M-Jup orbiting at a(p) = 1.0860(-0.0007)(+0.0006) aufrom the giant star HD 59686 A. In addition to the planetary signal, we discovered an eccentric (e(B) = 0.729(-0.003)(+0.004)) binary companionwith a mass of m(B) sin i = 0.5296(-0.0008)(+0.0011) M-circle dot orbiting at a close separation from the giant primary with a semi-major axis of a(B) = 13.56(-0.14)(+0.18) au. Conclusions. The existence of the planet HD 59686 Ab in a tight eccentric binary system severely challenges standard giant planet formation theories and requires substantial improvements to such theories in tight binaries. Otherwise, alternative planet formation scenarios such as second-generation planets or dynamical interactions in an early phase of the system's lifetime need to be seriously considered to better understand the origin of this enigmatic planet.
43
Morales, Gerard John Alva. « Estabilidade de Liapunov e derivada radial ». Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/45/45132/tde-19112014-174237/.
Texte intégralRésumé :
Apresentaremos uma classe de energias potenciais $\\Pi \\in C^{\\infty}(\\Omega,R)$ que são s-decidíveis e que admitem funções auxiliares de Cetaev da forma $\\langle abla j^s\\Pi(q),q angle$, $q\\in \\Omega \\subset R^n$ que são s-resistentes.We will present a class of potential energies $\\Pi \\in C^{\\infty}(\\Omega,R)$ that are s-decidable and that admit auxiliary functions of Cetaev of the form $\\langle abla j^s\\Pi(q),q angle$, $q \\in \\Omega \\subset R^n$ which are s-resistant.
44
Weiß, Jörg. « Modellbildung und Simulation radial gekoppelter Rotoren ». Doctoral thesis, Bericht ; 1/2008, 2005. https://monarch.qucosa.de/id/qucosa%3A18883.
Texte intégralRésumé :
In Produktionsanlagen mit radial gekoppelten Rotoren wie beispielsweise
Papier- und Druckmaschinen treten im höheren Drehzahlbereich störende
Schwingungen auf. Der Entstehungsmechanismus der Schwingungen ist im
nichtlinearen Verhalten der Kontaktstelle in enger Abstimmung mit der
elastischen Lagerung der Walzen zu suchen. In dieser Arbeit wird aus
maschinendynamischer Perspektive eine systematische Zusammenstellung von
Rotormodellen entwickelt. Durch die Auswahl eines geeigneten Kontaktpartners
wird das Modell vervollständigt. So kann ein Minimalmodell zur Untersuchung
von Schwingungsphänomenen entwickelt werden. Fokussiert auf die Beschreibung
der Koppelstelle werden geeignete Kontaktmodelle abgeleitet und vereinfachend
betrachtet. Ein zur Unterstützung der theoretischen Analyse entworfener
Versuchsstand diente zur Durchführung zahlreicher Versuche, die Parameterwerte
für die Berechnungsmodelle lieferten und Schwingungsphänomene belegten. Die
beschriebenen Modelle werden zur abstrahierenden numerischen Untersuchung
ausgebaut und genutzt.Paper- and printing machines contain radially coupled rolls. Vibrational phenomena has been experienced at higher rotational speeds. The mechanisms leading to these vibrations are to be found in a nonlinear contact behavior between the roller pairs. A systematic approach to modelling of rolls has been developed from a dynamics point of view. Selecting an appropriate contacting roll model, the roller pair model has been completed. The so obtained minimum model is best situated to work out the influence of selected parameters on the dynamical behavior. With the focus set on the coupling of the rolls a simplified contact model is developed. Experimental data are obtained from a testing rig in support of the theoretical analyses. Parameter values have been calculated from experimental results. As a conclusion, the simulation models show the vibrational phenomena observed at the test rig.
45
Iskra, Wlodzimierz, Markus Müller et Ingrid Rotter. « Radial pattern of nuclear decay processes ». Forschungszentrum Rossendorf, 1994. https://hzdr.qucosa.de/id/qucosa%3A22071.
Texte intégral
46
Dassy, Brice. « Adaptation to multiple radial optic flows ». Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/91229/.
Texte intégralRésumé :
There is long-standing evidence suggesting that our visual system can adapt to new visual environments, like a single radial optic flow generated when driving (Brown, 1931; Denton, 1966). In fact, as we move through the environment multiple optic flows can be generated. For example, when driving, we are often exposed to more than one radial optic flow at the same time. In this thesis I investigate whether the visual system can simultaneously adapt to two radial motion optic flows. More specifically, I explored this issue in three ways. First, I investigated whether the visual system could – through a fast low-level process – adapt to two optic flows present at two specific locations in space. Second, I probed whether the visual system could – through a perceptual learning process – learn to associate two radial optic flows with their locations in space. Third, I examined whether the visual system could – through a perceptual learning process – learn to associate each of two radial optic flows with preceding eye-movements. With regard to the first issue, the results from Experiments 1 – 6 suggested following exposure to two radial motion stimuli, a fast low-level process in the visual system could adapt to a radial flow pattern at one location in space: the radial flow pattern generated by the most recently presented radial motion stimulus. With respect to the second issue, the results from Experiments 7 – 10 indicated that the visual system could not learn to associate specific locations with two different radial motion stimuli. Finally, regarding the third issue, the results from Experiment 11 suggest that the visual system can associate specific eye-movements with two different radial motion stimuli. Taken together, these results suggest constraints on the way in which the visual system can adapt to radial motion, and emphasize the importance of self-movement in generating adaption to new visual environments.
47
Baart, Pieter. « Grease lubrication in radial lip seals ». Licentiate thesis, Luleå : Luleå University of Technology, 2009. http://pure.ltu.se/ws/fbspretrieve/2760890.
Texte intégral
48
Farrell, Patricio. « Multilevel collocation with radial basis functions ». Thesis, University of Oxford, 2014. https://ora.ox.ac.uk/objects/uuid:9fd99f0f-2556-41eb-8bcd-5b9256296a17.
Texte intégralRésumé :
In this thesis, we analyse multilevel collocation methods involving compactly supported radial basis functions. We focus on linear second-order elliptic bound- ary value problems as well as Darcy's problem. While in the former case we use scalar-valued positive definite functions for constructing multilevel approximants, in the latter case we use matrix-valued functions that are automatically divergence-free. A similar result is presented for interpolating divergence-free vector fields. Even though it had been observed more than a decade ago that the stationary setting, i.e. when the support radii shrink as fast as the mesh norm, does not lead to convergence, it was up to now an open question how the support radii should depend on the mesh norm to ensure convergence. For each case above, we answer this question here thoroughly. Furthermore, we analyse and improve the stability of the linear systems. And lastly, we examine the case when the approximant does not lie in the same space as the solution to the PDE.
49
Sargent, Ethan. « Radial Solutions to Semipositone Dirichlet Problems ». Scholarship @ Claremont, 2019. https://scholarship.claremont.edu/hmc_theses/229.
Texte intégralRésumé :
We study a Dirichlet problem, investigating existence and uniqueness for semipositone and superlinear nonlinearities. We make use of Pohozaev identities, energy arguments, and bifurcation from a simple eigenvalue.
50
García, del Blanco Bruno. « Influencia del modo de compresión tras la cateterización transradial percutánea en la oclusión de la arteria radial e impacto funcional de la misma ». Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/384526.
Texte intégralRésumé :
La enfermedad coronaria es la primera causa de mortalidad en nuestro medio. El estudio mediante angiografía con contraste o coronariografía se realiza en más de 140.000 casos al año en España, y en más de 70.000 casos se acompaña de tratamiento intracoronario para solucionar las dificultades al flujo coronario. Inicialmente el acceso a los ostia coronarios se realizaba vía femoral o braquial pero el desarrollo de los materiales y la calidad de imagen radiológica permite que en nuestro medio en más de un 90% de los casos se acceda por la vía arterial radial. Este acceso se ha ido adoptando progresivamente en la comunidad médica en gran parte porque se asocia con una reducción de acontecimientos clínicos El estudio que hemos llevado a cabo para estudiar la incidencia de la oclusión de la arteria radial tras la canulación además estudia la posible influencia del método utilizado para lograr la hemostasia y el potencial impacto en la funcionalidad de la mano. En otros accesos arteriales sabemos que la compresión influye en el grado de trombosis y oclusión arterial y también que los métodos de cierre percutáneo han aportado comodidad en la movilización del paciente pero no evitan las complicaciones asociadas al acceso arterial. Se diseñó un estudio exhaustivo con tres métodos de evaluación de la permeabilidad arterial (Test de Allen clínico, Pulsioximétrico y estudio con Eco Doppler) basal, a la semana y a los tres meses aleatorizando el método de compresión entre los pacientes consecutivos atendidos en nuestro centro en un período de 18 meses. A todos los pacientes se les realizaba un test de fuerza prensil de la mano estudiada con un dinamómetro específico y analizando la respuesta a dos protocolos distintos de fuerza prensil: una mantenida y otra de múltiples repeticiones. Se analizaron un total de 274 pacientes, 124 tratados finalmente con un método de compresión elástico o Tensoplast® y 150 pacientes con un método de compresión neumática Terumo®. A pesar de no detectarse diferencias en las características basales de los pacientes entre los grupos, en nuestro estudio la incidencia de oclusión arterial fue mayor a la semana en el grupo de compresión neumática independientemente del método usado para analizar la oclusión arterial. Esta diferencia se perdía a los tres meses por la mayor tasa de repermeabilización en el grupo de compresión neumática que fue superior al doble de la tasa de permeabilización tardía en el sistema elástico. La incidencia de oclusión de aparición exclusivamente tardía, a los 3 meses, era igual entre grupos mientras que la oclusión persistente en los dos controles fue superior en el grupo de compresión neumática. El análisis funcional de la mano con los tests de fuerza mantenida y los de repeticiones múltiples no detectaron diferencias según el método compresivo utilizado y tampoco mostraban diferencias si lo que analizábamos eran los pacientes con la arteria radial ocluida y los que ésta se mantenía permeable. El análisis anatómico en cambio sí que detectaba variaciones en los diámetros de las arterias del arco palmar si la radial estaba ocluida en el seguimiento: la radial canulada a la semana mostraba una tendencia a aumentar su calibre siempre, y si ésta estaba ocluida la cubital aumentaba significativamente su diámetro a la semana y también a los 3 meses. El flujo sólo mostraba cambios en la fase sistólica a la semana si la radial estaba ocluida, no en las otras situaciones. En definitiva la compresión neumática se asocia a mayor incidencia de oclusión radial a la semana, ésta no tiene impacto funcional pero sí se detecta en cambio un mecanismo adaptativo anatómico en la arteria contralateral: la cubital.Coronary artery disease is the first cause of death in our environment. Contrast angiography and coronariography was performed in more than 140.000 cases in Spain last year, in more than 70.000 cases an interventional coronary procedure was also done to treat coronary flow disturbances. The initial arterial access to the coronary ostia was historically through femoral or brachial access but recent material development and improvement in quality Rx image has helped to switch to radial artery access in more than 90% of the cases done in our hospital. Rapid and progressive adoption of radial access has been boosted in the medical community due to the better clinical results published in patients in whom radial access is used. The study that we have conducted to analyze the incidence of radial artery occlusion after transradial catheterization aimed to detect the influence of the compression method used to achieve homeostasis in artery occlusion and also studied the potential functional impairment of the patient’s hand affected. We know from previous studies that type of compression influences thrombosis and artery occlusion after catheterization. We also know that percutaneous closure devices contribute to faster patient mobilization but do not avoid arterial access typical complications. We designed a study with three different methods to explore radial artery permeability (Allen Clinical Test, Pulsioximetric Test and Eco Doppler exploration) at basal, 1 week after and 3 month after catheterization and the compression method being randomized to pneumatic force (Terumo®) or elastic compression (Tensoplast®) between all the patients treated consecutively in our center during a 18 month period time. We did a functional test of hand strength following two different protocols: one to test maintained strenght and the other to test Rapid Exchange repetitions with two interval specified tests. We analized 274 patients, 124 submitted finally to the elastic compression method Tensoplast® and 150 patients treated with a pneumatic compression method Terumo®. Despite there were not statistically significant differences in basal characteristics between both groups our study showed higher radial artery occlusion rate at one week in the Terumo ® group. This was consistently confirmed with the three different methods of radial artery occlusion used. The difference in the occlusion rate lost statistical significance at the analysis performed at 3 month due to a higher rate of recanalization of the radial artery occluded in the pneumatic group, being more than double of the one raised with the elastic method. Incidence of late occlusion detected only at 3 month period was equivalent in both groups while persistent occlusion was clearly higher in the Terumo® patients. Functional strength analysis with all the prespecified tests did not show any differences between methods of compression nor between patients that suffered radial occlusion against those whose radial was kept permeable. By the other hand anatomic analysis showed variation between arterial diameters related to radial occlusion: if these was present ulnar diameter was bigger at 1 week and also at 3 month time. Arterial blood flow increased at one week if radial was occluded specifically at its systolic phase, not at all the other possible situations. In summary pneumatic compression is associated with a higher incidence of radial artery occlusion at 1 week. This phenomenon has not functional impact in the patient’s hand strenght but an adaptive anatomic change is found in the contralateral vessel: the ulnar artery.