Neste trabalho estudamos as aplicações do método do Gradiente Espectral Projetado (SPG) em Meteorologia nos campos de previsibilidade, estabilidade e sensibilidade. Inicialmente revisamos os Vetores Singulares Lineares (LSVs) e em seguida apresentamos a teoria das Perturbações Condicionais Não-Lineares Ótimas (CNOPs). Enquanto os métodos clássicos estão baseados no Modelo Tangente Linear, as CNOPs são uma formulação do mesmo problema baseado em Programação Não-Linear. As CNOPs são descritas na literatura como responsáveis por melhorias em relação aos métodos anteriores. Finalmente analisamos três exemplos de aplicação do método à problemas de previsibilidade, estabilidade e sensibilidade. / A revision about applications of Spectral Projected Gradient (SPG) in meteorology is done in the fields of predictability, stability and sensitivity. Initially we review about Linear Singular Vectos (LSVs) and we present the Conditional Nonlinear Optimal perturbations (CNOPs). While the classic methods are based on the Tangent Linear Model, CNOPs are another formulation of the problem based on Nonlinear Programming. CNOPs are described in bibliography as responsible by better results than older methods. Finally we analyze three applications in predictability, stability and sensibility.

Neste trabalho estudamos as aplicações do método do Gradiente Espectral Projetado (SPG) em Meteorologia nos campos de previsibilidade, estabilidade e sensibilidade. Inicialmente revisamos os Vetores Singulares Lineares (LSVs) e em seguida apresentamos a teoria das Perturbações Condicionais Não-Lineares Ótimas (CNOPs). Enquanto os métodos clássicos estão baseados no Modelo Tangente Linear, as CNOPs são uma formulação do mesmo problema baseado em Programação Não-Linear. As CNOPs são descritas na literatura como responsáveis por melhorias em relação aos métodos anteriores. Finalmente analisamos três exemplos de aplicação do método à problemas de previsibilidade, estabilidade e sensibilidade. / A revision about applications of Spectral Projected Gradient (SPG) in meteorology is done in the fields of predictability, stability and sensitivity. Initially we review about Linear Singular Vectos (LSVs) and we present the Conditional Nonlinear Optimal perturbations (CNOPs). While the classic methods are based on the Tangent Linear Model, CNOPs are another formulation of the problem based on Nonlinear Programming. CNOPs are described in bibliography as responsible by better results than older methods. Finally we analyze three applications in predictability, stability and sensibility.

Le développement de différentes formes colloïdales pour la thérapie et le diagnostic médical ultrasonore connait un intérêt croissant depuis de nombreuses années. En particulier, les microbulles de perfluorocarbone (PFC) sont des agents de contraste intéressants, car le gaz est un puissant réflecteur des ultrasons. Plus récemment, les gouttelettes de PFC ont été proposées pour de nouvelles applications acoustiques. Suite à une impulsion acoustique, les ultrasons induisent un changement de phase de l’état liquide à l’état gazeux. Ce phénomène est appelé la vaporisation acoustique de gouttelettes. Parallèlement à l’étude de nouvelles applications, le développement de nouvelles techniques de préparation offrant un meilleur contrôle lors de la production, reste un enjeu primordial. Ainsi, de nouvelles méthodes de préparation basées sur des dispositifs membranaires semblent être particulièrement intéressantes. L’objectif de la thèse porte donc sur le développement de nouvelles techniques à membrane pour la formulation de microbulles et de microgouttelettes de taille contrôlée pour des applications en imagerie et thérapie ultrasonore. Dans ce travail, l’émulsification membranaire directe avec un module membranaire de type cross-flow a été utilisé pour la préparation de microbulles stabilisées par des tensioactifs solubles, tandis qu’un module de type microkit a permis l’obtention de microbulles stabilisées par des phospholipides. Dans un second temps, l’émulsification membranaire par prémix a permis de formuler des microgouttelettes de PFC monodispersées. Pour les différentes formes colloïdales préparées, nous avons observé l’influence des paramètres du procédé (pression, débit et contrainte de cisaillement), des paramètres de formulation (molécules stabilisatrices, type de PFC de la phase dispersée) et des paramètres de la membrane (taille des pores) sur la formation des microbulles/ microgouttelettes. Par la suite, la caractérisation acoustique des microbulles/microgouttelettes a montré que ces systèmes présentent les propriétés nécessaires pour être utilisés comme agents de contraste ultrasonores / The development of various colloidal forms for therapy and diagnosis in ultrasound medical present a great interest for many years. In particular, microbubbles of perfluorocarbon (PFC) are interesting as contrast agents because the gas is a high ultrasound reflector. More recently, PFC droplets have been proposed for news acoustic applications. Indeed, after an acoustic pulse, the ultrasound waves induce a phase change from the liquid state to the gaseous state. This phenomenon is called the acoustic vaporization of droplets. In parallel with the study of new applications, the development of new process offering a better control during production, remains a key issue.Thus, the preparation using news methods based on membrane devices seem to be particularly interesting. The aim of the thesis is the development of new membrane process for the formulation of microbubbles and droplets with a size controlled for ultrasound applications in imaging and therapy. In this work, the direct membrane emulsification with a cross-flow membrane module was used for the preparation of microbubbles stabilized by soluble surfactants, while a microkit module allowed to obtain microbubbles stabilized by phospholipids. In a second step, the membrane emulsification by premix allowed to formulate monodispersed droplets of PFC. For the various colloidal forms prepared, we observed the influence of the process parameters (pressure, flow rate and shear stress), the formulation parameters (surfactants, type of PFC of the dispersed phase) and the membrane parameters (pore size) on the formation of microbubbles/droplets. Subsequently, the acoustic characterization of microbubbles/droplets has shown that these systems have the properties to be used as ultrasonic contrast agents

Chip seals are a pavement surface treatment used for maintaining asphalt concrete pavements. National Cooperative Highway Research Program (NCHRP) Project 14-17 was performed to produce a national Chip Seal Manual which would consolidate the best chip seal engineering practices. A subcontract to NCHRP Project 14-17 performed at Texas A&M University was the basis for this thesis. It included the following tasks: investigation of a testing and grading system for grading asphalt binder residues from chip seal emulsions; and investigation of texture measurement methods for assessing existing pavement macrotexture before a chip seal is placed. The performance graded (PG) asphalt binder specification, which was developed to characterize asphalt binder properties related to the performance of hot mix asphalt concrete in pavements, cannot be directly applied to asphalt binders or emulsion residues for use in chip seals. Therefore, the surface performance graded (SPG) specification was developed using the same equipment as the PG system but with some procedural modifications and different limiting values for the test parameters. NCHRP Project 14-17 utilized the PG and SPG systems to grade base asphalt binders and recovered emulsion residues. Two emulsion residue recovery methods were compared: hot oven evaporation with nitrogen blanket and stirred can with nitrogen purge. The PG and SPG grades were found to be similar for the two emulsion residue recovery methods but slightly different from the base asphalt binder. A strawman specification for emulsion residues in chip seals was recommended for use with the stirred can recovery method. In chip seal construction, macrotexture of the existing pavement affects the rate at which chip seal emulsion must be applied. In this project, existing pavement macrotextures were measured at three chip seal projects immediately before construction using both the sand patch test and the circular track meter, CT Meter. The CT Meter was found to quickly and effectively measure pavement macrotexture. The CT Meter measurements correlated well with the sand patch test measurements. Finally, this project investigated the utility of measuring pavement macrotexture in the laboratory using the aggregate imaging system (AIMS) on pavement cores and on small samples cut from fabricated slabs. Statistical analyses showed good correlation between the mean profile depth, MPD, calculated from AIMS measurements on pavement cores and small samples, based on analysis using 50 mm (2 inch) segment lengths, and the MPD measured on the pavement or on the large fabricated slabs with the CTMeter. These results supported the use of AIMS to measure pavement macrotexture using small samples in the laboratory.

Blades used on brushcutters and lawn mowers are subjected to a wide variety of working conditions. Besides continuous loads from cutting grass, the blades are also subjected to accidental impacts of branches, stones and structures. Due to exceptionally high rotational velocities, these types of impacts involve blade deformation at high strain rates. This master’s thesis aims to improve understanding and predictability of blade properties for design of future blades. The project is aimed at characterization of the mechanical response of steel used for brushcutter blades and developing a simulation model of a blade impact load case. Thus, the problem was divided into two main parts: firstly, material characterization, and secondly, numerical modeling. The objective of the material characterization part was to determine the rate dependence of the flow stress for two hardened steels. Experimental compression tests were performed at quasi-static strain rates (10-4 - 10-2 s-1) and at high strain rates (102 - 104 s-1) in order to characterize the rate dependence of each material. The objective of the numerical modeling part was to develop simulation models of an impact load case for the purpose of recreating tests performed with an experimental test setup. The simulation models were aimed to include material models for the blade based on the experimental tests performed for the two hardened steels. In preparation for the compression tests, cylindrical specimens were acquired through electrical discharge machining involving material removal from blades intended for brushcutters. Compression tests at high strain rates were performed utilizing a split-Hopkinson pressure bar apparatus which resulted in strain rates in the order of 1000 s-1 and 3000 s-1. Compression tests at quasi-static strain rates were performed with an electro-mechanical loading machine and implementation of two-dimensional digital image correlation for strain measurements. With this method, strain rates in the order of 5 · 10-2 s-1 and 5 · 10-4 s-1 were achieved. The acquired results from the experimental tests included the response of the two materials at four different strain rates in the form of true stress-true strain curves. The results were indicative of small strain rate dependency for each of the two hardened steels with a slight increase in yield stress for increasing strain rates. Both materials exhibited closely similar characteristics. At quasi-static rates, the response of both materials exhibited work-hardening of closely similar characteristics. At high strain rates, the response of both materials exhibited a close to identical decrease in stress for values of strain exceeding 10 %. This behavior was suggested to be a consequence of adiabatic heating. At all four achieved strain rates, the results were indicative of a higher yield stress with higher subsequent stresses for one of the hardened steels in comparison to the other. The impact load case aimed to be simulated involved one swing of a brushcutter against a 25 mm diameter steel rod according to standard SS-EN ISO 11806-1:2011. The steel rod was specified to be impacted horizontally by the blade at an approaching translational velocity of 1 m/s and a blade rotational velocity of 8500 rpm. The multi-physics simulation software LS-DYNA was used to develop simulation models which consisted of two main parts, the blade and the rod and included two different blade geometries. As a result of a study regarding the suitability of different discretization techniques, the decision was made to implement the mesh-free particle method Smoothed Particle Galerkin (SPG) and to perform coupling with the finite element method (FEM). Two material models were developed based on the measured stress-strain response obtained through high strain rate compression testing. Several numerical models of the impact load case were produced, all of which entailed different sets of parameters. These included selection of blade material, failure strain, rod length and blade angle relative to the horizontal plane. Finally, two models were developed which were opposite in terms of assigned element formulation for the blade tip and the rod and otherwise identical. The results of the different models were then compared, namely in terms of resulting material failure of the blade after impact. It was concluded that SPG was the most suitable method of choice for the impact load case aimed to be simulated due to its ability to handle large deformation and the inclusion of the a bond-based failure mechanism. Furthermore, implementation of the SPG method resulted in deformation and failure considered to be of greater agreement to experimental test results compared to FEM.

When dealing with the separation of materials, the metal shearing process such as punching, is widely used in theindustry due to its time efficient manner. There is however, a need to better understand the process in order toimprove quality of the final product. Working with numerical simulations of themetal shearing process, there aretwo major difficulties. One being the extremely large deformation, the other being material failure. The combinationof these two makes numerical modeling challenging and is the reason for this study.The problem was divided in to two main parts, one where material modeling was studied, the other part focusedon numerical modeling and experiments of the punching process. A material model considering both plasticityandmaterial failure was created for a boron steel material. Plasticity behavior of thematerial was modeled with anelasto-plastic model and a calibratedModifiedMohr-Coulomb (MMC) failure criterion to model the material failure.The resultingMMC-model agreed well with the experiments.Punching experiments with varying clearances were performed on the boron steel. Punch forces and displacementswere continuously sampled throughout the process, and after the punching experiments were finished the punchededge profiles were studied. The multiphysics simulation software LS-DYNA was then utilized, and three dimensionalsimulations of the punching process using the Smoothed Particle Galerkin (SPG)method were performed.Results from the SPG-simulation corresponded very well with the results from punching experiments, and it can beconcluded that the model was able to capture the material behavior of the sheet in a highly detailed level. When thepunched edge profiles from the simulations were compared to the experiments, there was an almost exact match forall the cases studied. The force-displacement behavior of the punch from simulations was in great consistency withexperimental results as well.Itwas also concluded that the combination of a stress state dependent failure criterion together with the SPG-methodshows significant possibilities to cope with three dimensional problems where large deformations in combinationwith difficultmaterial failure occurs. This study focuses on the punching process, but the generality of this novelmodeling technique can be applied to many industrial cases and is a step towards a better and more reliablemodeling of failure in combination with extremely large deformation.

Grâce au SPG, l'Union Européenne accorde une réduction tarifaire douanière aux pays en développement (PED) afin de les aider à se développer. Les pays les moins avancés (PMA) et les pays vulnérables qui respectent une liste de normes relatives aux droits de l'homme, aux droits fondamentaux du travail, à la bonne gouvernance et à l'environnement sont eux, exempts de droit de douane sur le territoire communautaire. L'intérêt de l'utilisation du SPG est au cœur de cette étude qui a comporte deux parties. La première a trait au développement économique, la seconde au développement social et politique. Dans le titre premier, l'étude du cadre de la promotion du développement économique fait l'objet du premier sous-titre. Il s'attache à expliquer comment l'Union Européenne favorise certains pays (les PMA) et protège certains pans de son économie que ce soit en accordant un régime qui n'est pas totalement favorable à certaines marchandises (le textile et l'agriculture) ou grâce aux mécanismes de protectionnisme. En outre, ce sous-titre cherche à savoir quels avantages économiques l'Union Européenne peut tirer du SPG et s'il a été efficace dans son objectif de lutte contre la pauvreté dans les PED. Alors qu'il aura été expliqué que l'impact du SPG sur la réduction de la pauvreté n'est pas probant, le second sous-titre explique les raisons de cet échec. Les premières raisons sont externes au système. Alors que le notion de clause NPF est remise en question par la multiplication des accords commerciaux bilatéraux, par conséquent, celle de la marge préférentielle l'est aussi. Ces deux notions doivent donc être repensées. Il faut en discuter la pertinence dont dépend celle du SPG. En outre, l'importance des mesures non tarifaires et des services doit aussi être prise en compte dans l'évaluation du SPG qui est un instrument tarifaire. S'agissant des obstacles intrinsèques, le problème des règles d'origine occupe une place centrale. Plus globalement, la question de la simplification (et donc de la réduction des coûts) du SPG est abordée afin de savoir comment rendre le système plus efficace. Dans le titre second, le premier sous-titre est relatif au cadre (historique, normatif, géographique et méthodique) de la promotion des droits fondamentaux dans le SPG de l'Union Européenne. Le SPG+ et les aspects procéduraux font, quant à eux, y font aussi l'objet d'une attention particulière. Le second sous titre est consacré à l'intérêt de l'application des droits fondamentaux dans le SPG de l'Union Européenne. Ainsi, l'application des droits fondamentaux par les PED est positive pour l'économie de l'Union Européenne qu'il s'agisse ou non de leur aspect protectionniste. Concernant les PED, si une application des droits fondamentaux leur est bénéfique, elle n'en demeurent pas moins une charge. La possibilité de suspension du SPG en cas de violation des droits fondamentaux est peu invoquée, notamment par les ONG et les syndicats. Une tentative d'explication de ce phénomène est proposée dans le dernier chapitre de cette thèse. / Under the GSP program, the European Union provides customs tariff reduction to developing countries in order to help them improve their development. Goods of least developed countries (LDC) and vulnerable countries which respect a list of human rights, fundamental labour rights, good governance and the environment norms enjoy a duty free access to the EU market. The GSP utilisation's interest (the benefit ?) is the heart of this study wich include two parts. The first concern the economic developement, the second the social and political developement. In the first title, the economic developement promotion framework is the topic of the first sub-title. It tries to explain how EU favorises some countries (LDC) and protects some sectors of it economy (textile and agriculture). Furthermore, this subtitle seek to know what economical advantages EU can have with the GSP and if this instrument has been efficient in it aim to reduce the poverty in developing countries. While it will have been explain that the GSP's impact in the poverty reduction is not important the second subtitle explain the reasons of this fail. The first reasons are extern of the system. While the MFN notion is challenged with the bilateral trade agreement multiplication, consequently, preferential margin notion is questioned too. So, this notion have to be rethinked. Their relevance must be discuted because without a high MFN level, the GSP can't work. Furthermore, the non tariff measure and service importance must be taken into account in the GSP (a tariff instrument) evaluation. Regarding intern obstacle, rules of origine problem has a central role. More generally, the simplification (and so cost reduction) of the GSP is treated in order to know how the system can be more efficient. In the second title, the first subtitle concern the fundamental rights promotion framework (historical, normative, geogragraphical and methodical framework). The GSP+ and the processal aspect are also treaten in this subtitle. The second subtitle is dedicated to the fundamental rights application advantages in the UE GSP. So, the fundamental rights application by developing countries is positive for the EU economy whether or not their protectionnist aspect. Regarding developing countries, if a fundamental rights application is benefit, it can also be a burden. There are few GSP withdrawal request in case of fundemental rights violation, especialy by trade union and NGO. The last chapter tries to explain this fact.

Le Système de préférences généralisées (SPG) correspond à des réductions de droits de douane offertes par des sujets de droit international pubic « développés » aux pays en développement (PED). De manière générale, la conditionnalité est, quant à elle, un mécanisme qui permet de lier l’établissement, l’approfondissement, ou le maintien d’une situation juridique à la réalisation de conditions par un ou des bénéficiaire(s). Lorsque ce mécanisme est qualifié de « politique », ses conditions ont trait à la manière de gouverner et/ou à l’orientation des affaires publiques d’un sujet de droit international public. Le SPG de l’Union européenne (UE) contient plusieurs formes de conditionnalités qui agissent dans différents domaines des politiques publiques des PED bénéficiant de cette réduction douanière. L’intérêt de cette étude est d’aborder le SPG conditionné de l’UE dans le cadre de la construction de cette organisation internationale sui generis et comme révélateur d’une conception qui lui est particulière des relations internationales pour le développement. Par un effet miroir propre à chaque acte juridique, dans quelle mesure cet acte autonome reflète-t-il certaines caractéristiques de l’Union, une certaine identité de l’Union ? Le SPG conditionné de l’UE est tout d’abord un vecteur certain d’une identité européenne du développement en raison du caractère unilatéral de sa définition et de la relative uniformité de sa mise en œuvre. Cependant, celui-ci constitue un vecteur limité et ambivalent. Limité, tout d’abord, car le SPG est un acte secondaire au sein de la politique commerciale et car sa conditionnalité politique n’est pas reproduite dans d’autres actes des relations extérieures de l’Union. Ambivalent, ensuite, car cet acte autonome peut paraître illicite dans les relations commerciales internationales, tout en renouvelant le concept de développement par le commerce au sein de l’Organisation mondiale du commerce (OMC). / A Generalized System of Preferences (GSP) is a reduction in custom fees on exports from « developing » subjects of public international law to « developed » countries. As a general rule, conditionality is a tool used to establish, deepen or maintain a legal situation conditioned by specific behavior from it’s beneficiary(ies). This tool is qualified as « political » when it conditions governing tools and/or the public policy of a subject of public international law. The European Union’s GSP has several forms of conditionality which deal with the public of policy of the developing countries benefiting from reduced custom fees. This work aims to study the EU’s conditioned GSP in the context of this sui generis international organization’s construction and as evidence of a EU-specific conception of international relations for development. As each legal tool reflects it’s creator, how does this act reveal certain characteristics of the EU or even aspects of the EU’s identity ? The EU’s conditioned GSP is an expression of European identity as it is defined unilaterally and applied with relative uniformity. However, this expression is limited and ambivalent. First of all, limited, because the GSP is a secondary act within EU commercial policy and it’s political conditionality is not found in other elements of the EU’s foreign relations. Secondly, ambivalent, because this GSP can seem illegal in the context of international commercial relations, all the while renewing the concept of development-through-trade within the World Trade Organization (WTO).

Among the four valves of the heart, the aortic valve (AV) is frequently affected by disease. When progressive dilatation of the valve produces a leak when the valve should close (regurgitation), repair may be possible. AV repair is a desirable option because, contrary to AV replace-ment using a prosthesis, it does not require life-long anticoagulation treatment, and retains the original tissues that naturally combat structural degradation. All the AV repair procedures developed by cardiac surgeons require a good stabilization of the ventriculo-aortic junction (VAJ) diameter, through annuloplasty or reimplantation, for long-term success. In the present work, a preliminary design for a new type of annuloplasty ring is proposed that surgeons could tailor to the each valve’s shape and suture inside the VAJ. The design consists in wrapping a commonly available surgical biomaterial into a ring of controlled radial flexibility. For sizing and material selection, several models of increasing complexity were created to account for the anisotropic, hyperelastic nature of all the materials involved. First, an analytical model was programmed in MATLAB to assess the radial flexibility of annuloplasty rings formed with different biomaterials and select those that could match the physiological VAJ radial flexibility between systolic and diastolic pressures. The same program was also used to reproduce the experimental radial and longitudinal stretches of the human VAJ from 0 to 140 mmHg pressures. The analytical models were used to calibrate the parameters of independent finite element (FE) models of the VAJ and ring. Finally, the FE approach was extended to simulate the ring after suturing inside the VAJ, to determine the radial flexibility of the assembly under pulsatile pressure. Supple Peri-Guard® bo-vine pericardium patches used in transverse orientation emerged as the best currently available material option for the proposed ring, although a material providing more physiological radial flexibility would be desirable.

Saccharomyces cerevisiae is a unicellular eukaryotic organism capable of forming organized multicellular communities - colonies and biofilms. During development, colonies of laboratory strains differentiate into specifically localized cell subpopulations - U and L cells, located in the upper and lower part of the colony, respectively. The U and L subpopulations of cells vary in morphology, metabolic processes and stress resistance. Protein granules are membrane-less "organelles" found in both unicellular and multicellular eukaryotic organisms. The formation of protein granules is related to the physiological state of the cell (e.g. chronological and replicative aging), but also to changing environmental conditions and to cellular responses to stress factors. A relatively large fraction of proteins relocalizes to some type of protein granule during the lifespan of the cell. Granule formation can increase fitness of cells, help them to cope with limiting energy resources, and plays a crucial role in the adaptation of cells to stress conditions. Localization of many proteins in the cell varies depending on its physiology. Therefore the specific localization of such proteins may be considered as a "marker" of a specific physiological condition. There are proteins in each type of granule that can be...