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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Time Reversal Violation in Nuclear Effective Field Theory

Hockings, William Hill January 2006 (has links)
The lack of invariance with respect to time reversal (T) of the weak interactions has long been known. However, T violation has yet to be observed from flavor-diagonal sources, where the primary quantities of interest are electric dipole moments (EDMs). Weak T violation gives EDMs that are far too small, but strong T violation via flavor-diagonal sources could give EDMs strong enough to be detected in the near future. It is thus important to understand precisely how various quark-level sources of T violation manifest themselves in hadronic physics.A useful technique for dealing with low-energy phenomena involving nucleons, nuclei, and various mesons, is effective field theory (EFT). The formalism and methodology of EFT are presented, followed by an introduction to the construction of chiral Lagrangians.A motivation for the study of T violation beyond the weak interactions is then given, with brief introductions to the most important sources of T violation.The QCD theta term is looked at using two differentapproaches. First, enforcing vacuum stability at quark level, a series of T-violating interactions ensue. Second, enforcing vacuum stability at hadronic level via field redefinitions, spurious interactions are demonstrated to be avoidable. Both approaches involve a constraining relationship between theta-term T violation and up-down quark-mass-difference isospin violation. The quark chromo-EDMs are shown to be identical to the theta term in their chiral symmetry properties. The quark EDMs and Weinberg operator,conversely, are shown to generate new interactions in addition to those generated by the theta term, differing nucleon EDM contributions in particular.The electric dipole form factor (EDFF) of the nucleon, with a theta term source, is calculated in both leading and subleading orders in chiral perturbation theory, with the momentum dependence at both orders given entirely by contributions from the pion cloud. Theleading result is purely isovector, while an isoscalar result appears in subleading order. The isoscalar EDM is used as a lower-bound estimate of the deuteron EDM. The momentum dependence of the EDFF for small momentum transfer is related to the electromagnetic nucleonSchiff moment, which is computed to subleading order.
2

Optimisation de modèles comportementaux de composants pour la prédiction de défaillances fonctionnelles et matérielles liées aux décharges électrostatiques (ESD) / Behavioral model optimization of components for the prediction of soft and hard failures caused by electrostatic discharge (ESD)

Escudié, Fabien 11 December 2018 (has links)
Les événements transitoires de forte puissance (EFT - Electrical Fast Transient) sont l'une des préoccupations des concepteurs de systèmes embarqués. Ils peuvent conduire au dysfonctionnement du système et sont à l'origine d'un grand nombre de défaillances matérielles et fonctionnelles. Notre étude est principalement portée sur l'impact des décharges électrostatique (ESD - Electro Static Discharge) sur l'électronique embarquée dans un véhicule. D'après une étude de Renault, un véhicule peut subir deux décharges par jour durant sa vie. Les ingénieurs systèmes ne disposent pas de moyen pour prédire l'impact de ces décharges dans les systèmes, et les solutions actuelles sont essentiellement basées sur l'expérience. Afin de prédire le chemin d'un ESD dans tout le système électronique et la stratégie de protection à adopter pour protéger les composants les plus sensibles, des recherches dans le monde entier sont en cours. Les travaux de recherche du groupe ESE du LAAS-CNRS ont mené à des méthodologies de modélisation de composant passif, de circuit intégré et de carte électronique en VHDL-AMS. Les circuits intégrés sont dotés d'un réseau de protection ESD interne qui permet de détourner le stress des zones critiques. La méthodologie développée au cours des précédentes années permet de modéliser le comportement de ce réseau de protection. Cependant, ces modèles sont rudimentaires, ils décrivent uniquement le niveau de déclenchement de la protection et son impédance quasi-statique en fonction du niveau de stress ESD. Aucune information sur le comportement transitoire de la protection n'est décrite dans le modèle. Il est donc difficile de prévoir certaines défaillances liées aux phénomènes transitoires de déclenchement des protections faisant apparaitre de très fortes surtensions ou des niveaux de courant mal évalués. Les différents aspects abordés durant cette thèse permettent de résoudre ces problèmes en proposant des modèles dynamiques, et différentes méthodes pour pouvoir extraire les paramètres des modèles.[...] / Electrical Fast Transient (EFT) are one of the concerns of embedded system engineers. They can lead to system malfunction. EFT are the cause of a large number of hardware and software failures. Our study is mainly focused on the impact of Electro Static Discharge (ESD) on embedded electronic systems, focusing on car's applications. According to a Renault's study, a car can suffer two discharges per day during its entire life. System engineers do not have any tools to predict the ESD impact on the systems. In order to predict the ESD path throughout the electronic system and adjust the ESD protection strategy to provide proper protection for all critical components, some researches around the world are in process. The research results from ESE working group from the LAAS-CNRS laboratory, were mainly on passive components, integrated circuits and electronics boards modeling methods, implemented in VHDL-AMS language. Integrated circuits have an internal ESD protection network that helps to deflect the stress from critical areas. The methodology developed in the last few years allows to model the behavior of this protection network. However, these models are basically made, they are made of the triggering level of the protection and the impedance value of the component depending on the ESD stress amplitude. No information on the transient behavior of the protections is included in this model. It is not possible to predict some failures related to the transient phenomenon of the protection like triggering and turning on time that induce very high overvoltage or mismatch on the current levels estimation. The various topics covered during this thesis allows to solve these problems by using a, proposed dynamic model. Different methods are proposed to extract the parameters used into the dynamic model. One important point also aborted into this document is that the model have to be able to predict the soft failure which can appear in the system during an ESD stress.[...]
3

Equine-Facilitated Therapy and Trauma: Current Knowledge, Future Needs.

Staudt, Marlys, Cherry, Donna J. 24 September 2017 (has links) (PDF)
Equine-facilitated therapy (EFT) is a relatively new treatment for trauma and PTSD. EFT as well as animal assisted interventions in general have been introduced and implemented in mental health treatment for children and adults, though the research in support of these interventions has not kept up with practice. The purpose of this review is to examine the use of EFT for clients suffering from trauma/PTSD. Studies were included if PTSD/trauma was assessed and/or was measured as an outcome. A search of relevant databases resulted in nine peer-reviewed studies that met criteria. Studies are summarized and implications for future research are discussed. In general, findings suggest that EFT is a promising intervention for trauma/PTSD. Recommendations include a call for more research that includes veterans as well as for research that explicates the mechanisms by which EFT may be effective.
4

Effective field theory description of α cluster nuclei: The 9 Be ground state and 9 Be photodisintegration

Filandri, Elena 13 April 2022 (has links)
In this Thesis we present a description of α cluster nuclei, in particular focusing on the case of 9 Be, with αn and αα interactions derived from Cluster Effective Field Theory (EFT). The two-body potentials are regularized by a Gaussian cutoff which cures the short-distance dependence of the interaction and the potential parameters are found comparing the effective range expansion (ERE) with the calculated T-matrix. The calculation of the ground-state energies is carried out by diagonalizing the Hamiltonian on a Non symmetryzed Hyperspherical Harmonics basis in momentum space. Using only two body interactions a rather strong cutoff dependence appears. However, we are able to reproduce the experimental ground-state energies for selected cutoff values for most of the studied nuclei. The strong cutoff dependence indicates the lack of three-body forces, therefore we extend our Cluster EFT approach by including such many-body forces. Finally, the 9Be photoabsorption cross-section is studied via the Lorentz integral transform method (LIT), focusing on the low-energy resonances coming from the electric dipole transitions. By fine tuning the parameters of the three-body force, we are able to reproduce, up to 4 MeV, the considered experimental resonances. For the description of the spectrum at higher energies the inclusion of the αα D-wave potential seems to be necessary.
5

Experiential Theories: AEDP and EFT

Donald, Emily J. 01 October 2018 (has links)
No description available.
6

KBT och EFT - en jämförande litteraturstudie mellan två behandlingsmetoder för GAD / CBT and EFT - a comparing literature study between two treatment methods for GAD

Olsson, Lina January 2021 (has links)
Generaliserat ångestsyndrom (300.02), GAD, är en kronisk, funktionsnedsättande sjukdom som innebär ökad risk för psykisk och somatisk samsjuklighet samt skadligt alkoholbruk.  Farmakologisk behandling och/eller KBT psykoterapi rekommenderas, men många blir inte hjälpta av standardbehandlingen. På senare år har fokus riktats mot affekter och dess betydelse för psykiatriska åkommor och behandlingsresultat. Affektteorin utgör en central del i många terapiformer och studier visar att lidandet minskar om patienten kommer i kontakt med sina smärtsamma känslor. Syftet med denna uppsats är att jämföra innehåll, skillnader och likheter, mellan KBT och en affektfokuserad terapiform; Emotionsfokuserad terapi (EFT). En kvalitativ litteraturstudie genomförs och datan analyseras med inspiration från teorin om beskrivande metasyntes. Resultatet visar på både skillnader och likheter, största likheten är synsättet att oron används som copingstrategi för sådant som upplevs alltför skrämmande eller smärtsamt. Båda modellerna beskriver nödvändigheten av närmande av det förut undvikna.  Största skillnaden är att EFT fokuserar på förändringen av de underliggande smärtsamma primära känslorna, medan KBT fokuserar på att minska den sekundära oron. Slutsatsen är GAD-patienternas oro i KBT hanteras genom adressering av det synliga beteendet och tankarna kopplade därtill, medan man i EFT intresserar sig främst för de underliggande maladaptiva känslorna som anses leda till oro och undvikande.
7

A search for dark matter with bottom quarks

Kruskal, Michael 13 February 2016 (has links)
Despite making up over 80% of the matter in the universe, very little is known about dark matter. Its only well-established property is that it interacts gravitationally, but does not interact with ordinary matter through any of the other known forces. Specific details such as the number of dark matter particles, their quantum properties, and their interactions remain elusive and are only loosely constrained by experiments. In this dissertation I describe a novel search for a particular type of dark matter that couples preferentially to heavy quarks, using LHC proton-proton collisions at ATLAS. With a model-independent framework, comparisons are made to results obtained from other dark matter searches, and new limits are set on various interaction strengths.
8

Bayesian Model Mixing for Extrapolation from an EFT Toy

Connell, Matthew 18 May 2021 (has links)
No description available.
9

Bayesian Errors and Rogue Effective Field Theories

Klco, Natalie 27 April 2015 (has links)
No description available.
10

Topics In Effective Field Theories for the Strong Interaction

Thapaliya, Arbin 23 September 2016 (has links)
No description available.

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