Dissertations / Theses on the topic 'Binarité'

L'œuvre de Martín Kohan (Buenos Aires, 1967), écrivain prolifique à la notoriété grandissante au sein de la littérature argentine contemporaine, est l'objet de ce travail de recherche. Nous abordons le corpus - constitué par l'essentiel de l'œuvre : huit romans sur les neuf publiés à ce jour, La pérdida de Laura (1993), El informe. San Martín o el otro cruce de los Andes (1997), Los cautivos. El exilio de Echeverría (2000), Dos veces junio (2002), Segundos afuera (2005), Museo de la Revolución (2006), Ciencias morales (2007), Cuentas pendientes (2010); et deux recueils de nouvelles, Muero contento (1994), et Una pena extraordinaria (1998), principalement - sous l'angle de l'antagonisme, motif essentiel de l'univers fictionnel de Kohan, non seulement sur le plan de la diégèse mais également sur celui de la forme. Ce travail part de l'observation d'une constante au sein d'un corpus pourtant très varié : un rapport dichotomique, fait d'incompréhension et parfois de violence, entre la culture populaire ou la culture de masse, et la culture lettrée. La première partie de la thèse en propose une analyse systématique dans les cinq romans qui abordent explicitement ce type de conflit sous les modalités les plus diverses. La deuxième partie explore d'autres procédés qui tendent à confirmer le rôle structurant de l'antagonisme au sein de l'œuvre : si la mise à mal de l'union amoureuse semble exprimer la fatalité du malentendu, la dévalorisation des personnages du " milieu " et de la figure du consensus d'une part, et l'aspect revigorant des conflits menés à leur dernière extrémité d'autre part, révèlent l'aspect positif et particulièrement dynamique de l'antagonisme. La dernière partie se consacre aux implications de ce motif, omniprésent au point de représenter une nécessité : sur le plan politique - car sans être réaliste, la littérature de Kohan met en action la révolution marxiste en élaborant des figures de contre-pouvoir - ; sur le plan littéraire, où l'antagonisme montre toute sa fécondité. Le rapport hypertextuel, établi notamment avec des textes qui font autorité dans la littérature nationale, en est une expression essentielle ; mais la dichotomie est aussi une composante qui se manifeste à tous les niveaux de l'écriture, de l'unité minimale du mot à l'architecture complexe des romans. À la lutte entre personnages fait écho celle - défi formel le plus ambitieux - qui se joue entre le fond et la forme, source d'inépuisable ambivalence qui constitue l'une des spécificités les plus intéressantes de cet écrivain brillant.

La population galactique des nébuleuses planétaires (NP) permet d'apporter de précieuses contraintes pour améliorer notre compréhension de multiples problèmes astrophysiques tant à l'échelle de la Galaxie qu'à celle de l'évolution stellaire. Les NP sont détectables à de grandes distances, car leur rayonnement est concentré en de brillantes raies d'émission, dont la position et l'intensité permettent de déterminer leurs vitesses radiales et abondances chimiques. Appartenant à une population stellaire plutôt âgée, les NP sont particulièrement abondantes dans le bulbe galactique, et leur cinématique est un robuste traceur de la dynamique de cette région. Les gradients chimiques permettent aussi de contraindre les modèles chemico-dynamiques de la Galaxie. A une échelle toute différente, les étoiles centrales des NP (ECNP) permettent une description améliorée des stades finaux très mal connus de l'évolution des systèmes d'étoiles doubles. Pour que ces diverses études puissent être conduites correctement, un échantillon significatif de la population des NP doit être constitué. Le nombre de NP connues a été récemment doublé par le"Macquarie/AAO/Strasbourg Halpha (MASH) PNe catalogue" et atteint environ 2 700 NP en 2009. Le catalogue MASH-II est un supplément de MASH et contient plus de 360 nouvelles NP galactiques, découvertes suite à un sondage profond de tous les 233 champs du relevé AAO/UKST SuperCOSMOS Halpha en sa version digitale. De nouvelles techniques semi-automatiques de traitement de données et de visualisation multi-longueur d'ondes ont été developpées afin de maximiser la sensibilité de la recherche. Les NP de MASH-II se révèlent soit très petites et de brillance de surface élevée, soit très étendues avec une brillance de surface extrêmement faible. Plus de 90\% du catalogue a été confirmé spectroscopiquement au cours d'une vaste campagne d'observation. Le catalogue est disponible pour la communauté via le service vizir du Centre de Données astronomiques de Strasbourg (CDS). Cette thèse est basée sur l'exploitation des catalogues MASH et MASH-II représentant l'échantillon le plus vaste, le plus homogène, et le plus représentatif des NP dans la direction du centre galactique, offrant une opportunité unique de contribuer efficacement à deux domaines de recherche encore peu explorés : (i) La cinématique du bulbe galactique, et (ii) Le rôle de la binarité des étoiles centrales de NP. De nouvelles vitesses radiales ont été mesurées pour des centaines de NP dans la direction du bulbe, avec le spectrographe à fente du télescope ANU 2. 3-m et la spectroscopie à haute sensibilité des équipements multi-objets AAT 2dF/AAOmega et VLT FLAMES. De nombreuses mesures ont été effectuées pour beaucoup de NP résultant en un catalogue plus précis de 1200 NP dans la zone de longitude inférieure à 30° qui est couverte à 95%. L'étude cinématique a conduit à une courbe de la rotation du bulbe de pente 104 km/s/kpc en excellent agrément avec la valeur de 100 km/s/kpc determinée pour les étoiles géantes M. Des distributions cinématiques diverses ont été calculées et comparées en bon agrément avec celles d'autres populations traceurs, afin de mieux contraindre un modèle dynamique du bulbe. Dans le domaine des étoiles centrales (ECNP), une approche nouvelle et très performante a été conçue pour découvrir un grand nombre de ECNP binaires. Il s'agit d'analyser les séries de relevés photométriques d'environ 300 NP du bulbe sur le relevé OGLE-III (microlensing survey). Des variations périodiques ont été trouvées pour 21 ECNP binaires possibles, après l'élimination de 27 fausses identifications (NP mimics) détectées grâce à la spectroscopie à haute résolution. La distribution des périodes est dominée par des périodes plus courtes qu'un jour, ce qui implique que ces binaires très rapprochées auraient été produites via la phase d'enveloppe commune (common-envelope CE) de l'évolution de systèmes binaires. Ces découvertes ont doublé la population de ECNP binaires serrées, ce qui permettra pour la première fois une importante avancée dans la connaissance de l'évolution de la phase CE des binaires. La spectrométrie Gemini GMOS de 14 ECNP de l'échantillon OGLE confirme 10 « bona fide » ECNP binaires, plus 2 probablement binaires, et 2 à rejeter. De plus trois candidates au centre de petites NP devront être confirmées par une spectrométrie future, ainsi que quatre autres candidates situées au centre de NP plus étendues. Des étoiles géantes froides ont été révélées comme compagnons d'au moins deux ECNP binaires, et pour d'une d'elles la photométrie UV a révélé l'existence de la primaire invisible dans le spectre optique. Ceci suggère que des compagnons froids seraient plus fréquents que ce que l'on supposait, et permet d'éliminer des scénarios plus exotiques souvent évoqués (p. Ex. Born-again scénario). La distribution des périodes observée apparaît biaisée vers les périodes plus courtes que celles prédites par les modèles courants de synthèse de population CE. Un seul modèle de la littérature est compatible avec la distribution observée - à l'inverse de modèles plus récents. Les binaires serrées représenteraient une fraction d'au moins 10—20 % de l'ensemble des ECNP. Après une attentive prise en compte d'effets de sélection et autres limites des relevés, nos estimations apparaissent plus robustes que les estimations conduites au cours des 20--30 ans dans le passé avec des biais très incertains. Le rôle de la binarité est certainement primordial pour comprendre la morphologie des nébuleuses. Au vu de la proportion élevée de binaires serrées, au moins 10 à 20% des NP auraient du être modelée par la binarité, mais à ce jour aucune morphologie spécifique n'avait été identifiée pour les rares NP à noyau binaire serré connues. Nous avons découvert qu'environ 30% d'un échantillon de 30 NP post-CE soigneusement sélectionnées présentent une morphologie bipolaire typique. Une fraction d'au moins 60% de NP bipolaires est atteinte si on considère les variations d'inclinaison et d'autres effets. Il s'agit de l'étude la plus convaincante à ce jour montrant que la morphologie observée des NP post-CE est tout à fait compatible avec les conjectures théoriques de la formation de hauts contrastes de densité pendant la phase CE. Des structures de basse ionisation (Low Ionisation Structures LIS) sont souvent observées dans les NP post-CE. LIS apparaissent confinées soit comme des filaments ou noeuds distribués radialement dans le plan orbital, ou comme des jets à faible brillance de surface dans les régions polaires. La binarité de ECNP expliquerait aussi les LIS apparaissant autour de noyaux à émission, où une ou plusieurs phases CE auraient créé la morphologie observée et la chimie complexe des poussières (dual-dust-chemistry). Une oigine binaire expliquerait aussi la distribution (durant la phase CE) dans le plan orbital de condensations neutres de poussières et molécules d'hydrogène, qui seront ensuite photoionisés durant la phase NP. Si ce scénario binaire est avéré, les abondance d'azote des NP avec LIS doivent être revues, car les émissions [NII] observées ne seraient pas le résultat de matériau stellaire enrichi, mais seraient plutôt dues à des chocs proposés dans des modèles avec des abondances standard
The Galactic population of planetary nebulae (PNe) offers great potential in improving our understanding of many astrophysical problems on both large and small scales. They are revealed out to large distances by their bright emission line spectra from which their radial velocities and chemical abundances can be measured. As members of the old stellar population, PNe are particularly abundant towards the Galactic bulge where their kinematics are a valuable, relatively unbiased tracer of the dynamics of the region. Chemical abundance variations may also be traced by PNe to place constraints on chemodynamical models of the Galaxy. On much smaller scales their central stars (CSPN) are a powerful window into the poorly understood later stages of binary stellar evolution. The capacity of PNe to perform these studies is critically dependent on the size of the population. The current Galactic population of PNe was recently doubled by the Macquarie/AAO/Strasbourg Halpha (MASH) PNe catalogue. A supplement to MASH, the MASH-II catalogue, is presented with more than 360 new Galactic PNe found after a thorough search of all 233 AAO/UKST SuperCOSMOS Halpha Survey fields in digital format. Novel semi-automated data processing and multi-wavelength visualisation techniques are developed to maximise the sensitivity of the search. MASH-II PNe are notable for being either small, star-like PNe of relatively high surface brightness, or very large, extremely low surface brightness PNe. Over 90% of the catalogue is confirmed spectroscopically during extensive observing campaigns and the catalogue is available via the vizier catalogue service at the Centre de Donn\'ees Astronomiques de Strasbourg (CDS). This thesis is based on the exploitation of the MASH and MASH-II PNe catalogues that have provided the largest and most representative sample of PNe towards the Galactic bulge. This offers a unique opportunity to contribute towards two different, largely unexplored research domains: (i) The kinematics of the bulge, and (ii) The role of binary central stars of PNe. Radial velocities of hundred of Pne towards the Bulge were measured from ANU 2. 3-m longslit spectroscopy and from deep spectroscopy conducted with the AAT 2dF/AAOmega and VLT FLAMES multi-object spectroscopy facilities. Multiple measurements were recorded for many PNe resulting in a more accurate catalogue of about 1200 PNe within the longitude smaller than 30° region reaching a very high completeness of 95%. The kinematic study enabled a slope of 104 km/s/kpc for the rotation curve of the bulge that is in excellent agreement with 100 km/s/kpc determined from M-giants. General kinematic profiles were calculated and compared well with other tracer populations to bring new constraints on a dynamical model of the bulge. A completely new and powerful approach is conceived to discover large numbers of binary CSPN. The concept was employed to analyse the time-series photometry of nearly 300 Galactic bulge PNe from the OGLE-III microlensing survey. A total of 21 periodic binary CSPN candidates were found after careful elimination of 27 PN mimics identified using deep spectroscopy. The orbital period distribution is dominated by periods less than one day which indicates these binaries must have been produced via the common-envelope (CE) phase of binary stellar evolution. These discoveries have effectively doubled the population of close binary CSPN whose potential in advancing our knowledge of CE evolution has yet to be realised. Gemini GMOS spectroscopy of the 14 members of the OGLE sample produces 10 bona fide binary CSPN, 2 likely binary CSPN and 2 unlikely associations. There remains three candidates in the centre of small nebulae which leave little doubt of their bona fide status pending future spectroscopy, while four other candidates lie in larger nebulae awaiting confirmation. Cool giant companions are revealed in at least two binary CSPN and in one instance UV photometry proves the existence of the primary invisible in the optical spectrum. This suggests cool central stars may be more common than previously thought and more exotic scenarios explaining their presence can be ruled out. The observed orbital period distribution is found to be biased towards shorter periods than predicted by CE population synthesis models. Only one model in the literature matches the distribution reasonably well, but more recent models could not reproduce its predictions. A close binary fraction of at least 10--20% is estimated for PNe. After consideration of selection effects and other limitations of the survey, our estimate is found to be more robust than the previous estimate obtained from previous a survey conducted over 20--30 years with uncertain biases. Of particular interest is elucidating the role of binarity in the shaping of nebular morphologies. The close binary fraction imposes that at least 10--20% of PNe have been heavily shaped by a close companion, however no clear morphological properties have been identified amongst PNe with close binary CSPN. Nearly 30% of a carefully selected sample of 30 post-CE nebulae are found to have canonical bipolar morphologies. A very plausible bipolar fraction of at least 60% is reached once the inclination and other effects are considered. This is the strongest indication yet that the morphologies of post-CE nebulae largely satisfy theoretical expectations of a high density contrast established during the CE phase. Low ionisation structures (LIS) are common amongst post-CE nebulae suggesting they have a binary origin. LIS seem confined to either the orbital plane as radially distributed knots or filaments, or to the polar regions as (mostly) low surface brightness jets triggered by a dynamo effect. A binary origin may also be responsible for LIS around emission-line nuclei whereby one or more CE phases created the identifiable morphology and dual-dust chemistry. A likely binary formation scenario for LIS includes the distribution of neutral clumps of dust and H2 during the CE phase into the orbital plane that are then photo-ionised by winds during the PN phase. If the binary scenario holds then Nitrogen abundances for PNe with LIS would be rendered meaningless since the [NII] emission observed is not a result of enriched stellar material, but rather reflects shocked emission generated with models that assume standard abundances

La binarité sexuée est une vérité qui semblait, jusqu’à aujourd’hui incontestée et incontestable. Si bien que, mises à part les désignations genrées présentes dans le Code civil, ce dernier n’a pas jugé utile de préciser que les sexes qui devaient être inscrits sur les actes de l’état civil, devaient être exclusivement féminin ou masculin. Cependant, en pratique, l’appartenance exclusive à l’un des deux sexes consacrés n’est pas une règle universelle.C’est ainsi que les états d’intersexuation sont venus ternir le tableau, en affirmant que le sexe n’était pas une entité unique mais un bloc de différentes composantes, objectives et subjective, qui ne sont pas nécessairement concordantes entre elles. D’une part, l’intersexuation physique, se caractérisant par une variation du développement génital (V.D.G.) s’analyse comme une non concordance des composantes objectives du sexe, c'est-à-dire, toutes celles qui dépendent d’un déterminisme biologique. D’autre part, l’intersexuation psychique, autrement appelée transsexualisme, ou dysphorie de genre, ne sous-entend qu’une discordance entre les composantes objectives et la composante subjective, le sexe psychosocial. En d’autres termes, la personne est biologiquement d’un sexe déterminé, mais elle se sent appartenir à l’autre sexe.Ces deux états ont vocation à remettre en cause la place du sexe dans les actes de l’état civil à deux niveaux. D’un côté, les personnes dites « intersexes » vont nous faire nous interroger sur la véritable valeur de l’état civil si ce dernier ne prend pas en compte la variation dans ses énonciations. Seulement, cette interrogation semble être contrée par certaines pratiques médicales, qui, sous la contrainte à la fois des parents et de la société binaire, assignent des jeunes intersexes dans les jours qui suivent la naissance, alors même qu’aucune nécessité médicale ne vient justifier cet acte. De l’autre côté, les personnes transsexuelles remettent en cause les fondements de l’état des personnes et notamment le principe de l’immutabilité.De plus, les certitudes sur le sexe en Droit sont bouleversées par le développement des droits fondamentaux issus d’une interprétation toujours plus large de l’article 8 de la C.E.D.H. Ainsi, découle du droit au respect de la vie privée, le droit à l’épanouissement personnel, qui lui-même a rendu possible l’émergence des droits relatifs à l’identité, dont l’identité de genre. Ils se divisent en deux entités avec d’une part, le droit à la construction de l’identité de genre et d’autre, le droit à sa reconnaissance.Toutes ces considérations ont fait muter la mission de l’état civil, qui ne remplit plus uniquement une mission identifiante et de police civile au bénéfice de l’État et de l’intérêt général, mais qui devient le lieu privilégié des revendications identitaires, au bénéfice des individus. Dès lors, le genre devient admis en Droit, d’autant plus que la C.E.D.H. se positionne en faveur du développement de cette seconde mission.Au regard de ces éléments, nous pouvons affirmer qu’une réforme de la mention du sexe à l’état civil est opportune, ne serait-ce que pour éviter les probables condamnations de la Cour européenne. Cette réforme devrait assurer le respect dû à la vie privée des personnes en état d’intersexuation tant en limitant les situations stigmatisantes dont elles pourraient être victimes. Elle pourrait par ailleurs, prendre deux formes selon qu’elle se placerait en faveur d’un abandon ou de la mise en place d’une nouvelle mention. Dans la première hypothèse, une neutralisation du sexe serait envisagée et pourrait prendre deux formes. La première s’analyse en une neutralisation totale, c'est-à-dire, qu’aucune mention du sexe n’apparaitrait sur les actes de l’état civil. La seconde serait partielle dans la mesure où le sexe serait une mention cachée, ou rationnalisée, avec l’aide de nouvelles techniques d’identification, comme la biométrie
The sexed binarity is a truth which seemed, until now uncontested and undeniable. So that, put except for designations genrées present in the Civil code, this last considered to be useful to specify only the sexes which were to be registered on the acts of the civil status, were to be exclusively female or male. However, in practice, the exclusive membership of the one of the two devoted sexes is not a universal rule.Thus the states of intersexuation came to tarnish the table, by affirming that the sex was not a single entity but a block of various components, objective and subjective, which are not necessarily concordant between them. On the one hand, the physical intersexuation, being characterized by a variation of the genital development (V. G. D.) is analyzed like nonan agreement of the objective components of the sex, i.e., all those which depend on a biological determinism. In addition, the psychic intersexuation, otherwise called transsexualism, or dysphorie of kind, implies only one discordance between the objective components and the subjective component, the psychosocial sex. In other words, the person is biologically of a determined sex, but it feels to belong to the other sex.These two states have authority to call into question the place of the sex in the acts of the civil status on two levels. On a side, the people known as “intersexes” will make us wonder about the true value of the civil status if this last does not take into account the variation in its statings. This interrogation seems to be countered by certain practices medical, which, under the constraint at the same time of the parents and the binary company, assigns young people intersexes in the days which follow the birth, while at the same time any medical need does not come to justify this act. Other side, the people transsexuals call into question the bases of the state of the people and in particular the principle of immutability.Moreover, the certainty on the sex in Right are upset by the development of the basic rights resulting from an interpretation increasingly broader of article 8 of the C.E.D.H. Thus, rises from the right to the respect of the private life, the right to the personal blooming, which itself made possible the emergence of the rights relating to the identity, of which gender identity. They are divided into two entities with on the one hand, the right to construction of the gender identity and other, the right to its recognition.All these considerations made transfer the mission of the civil status, which does not fulfill only any more one identifying mission and of civil police for the benefit of the State and the general interest, but which becomes the privileged place of the identity claims, for the benefit of individuals. Consequently, the kind becomes allowed in Right, more especially as the C.E.D.H. positions in favour of the development of this second mission.Taking into consideration these element, we can affirm that a reform of the mention of the sex to the civil status is convenient, would be this only to avoid the probable judgments of the European Court. This reform should ensure the respect due to the private life of the people in a state of intersexuation so much by limiting the stigmatizing situations of which they could be victims. It could in addition, to take two forms according to whether it would be placed in favour of an abandonment or installation of a new mention. On the first assumption, a neutralization of the sex would be considered and could take two forms. The first is analyzed in a total neutralization, i.e., that no mention of the sex appears on the acts of the civil status. The second partial insofar as the sex would be a hidden mention, or would be rationalized, with the assistance of novel methods of identification, like biometrics

Les étoiles multiples sont nombreuses, tant parmi les objets jeunes de faible masse, les étoiles T Tauri, que parmi les astres de la Séquence Principale (SP). En ce qui concerne les étoiles jeunes de masse intermédiaire, les étoiles Ae/Be de Herbig (HAeBe), le statut de la binarité est peu connu. Nous avons réalisé une recherche systématique de binaires HAeBe en utilisant deux techniques: l'imagerie à haute résolution angulaire avec la méthode de l'Optique Adaptative d'une part, et la spectroscopie visible à haute résolution d'autre part. Ces techniques complémentaires nous ont permis d'identifier plus d'une vingtaine de nouvelles étoiles binaires; la fréquence de binarité déduite est d'au moins 50 %, voir supérieure à cause des biais observationnels discutés dans la thèse. Pour la première fois, les types spectraux des compagnons ont pu être déterminés dans une vingtaine de systèmes visuels. Les implications de nos observations pour la présence de disques de poussières et la détection d'émission X dans les étoiles HAeBe sont présentées. Les contraintes apportées pour les théories de formation des binaires sont discutées. Une partie importante de la thèse est consacrée à une étude approfondie de l'étoile triple TY CrA, l'unique système spectroscopique hiérarchisé parmi les étoiles Ae/Be de Herbig. Après une description complète des paramètres orbitaux et stellaires, la modélisation de la dynamique de cet objet particulier a été réalisée. Nos calculs théoriques montrent que la cohésion du système est assurée par effet de marée à l'oeuvre dans la binaire à éclipse centrale. L'environnement circumstellaire de TY CrA a également été étudié à partir d'observations spectroscopiques infrarouges avec le télescope spatial ISO et à partir d'images en Optique Adaptative dans le proche infrarouge.

La protection des populations civiles en cas de conflits armés, internationaux ou internes est au centre des préoccupations du droit international humanitaire contemporain. C’est un sujet digne d’intérêt et d’études plus approfondies. Dès lors, la recherche ici entreprise concernant l’apport du droit musulman à l’universalité des règles humanitaires protégeant les personnes civiles ainsi que des spécificités de ces règles, surtout en termes de leurs compatibilités avec celles développées par le droit international humanitaire contemporain ne pourraient que répondre à cet objectif. En effet, cette thèse, née du constat selon lequel les pays musulmans ont rapidement adhéré aux différents instruments du droit international humanitaire, tentera de démontrer pourquoi et comment se manifeste une telle convergence, voire homologie, entre les règles du droit musulman protégeant les personnes civiles en cas de conflits armés et celles développées par le droit international humanitaire contemporain. La confrontation-association entre ces deux systèmes - qui tiendra compte du contexte historique et de l’environnement dans lequel s’est développé le droit musulman- nous autorise, en effet, à défendre l’idée selon laquelle le droit musulman et le droit international humanitaire contemporain partagent les mêmes valeurs fondamentales en ce qui concerne la protection des populations civiles dans les conflits armés. Cette démarche nous permet également d’affirmer que la convergence entre les deux systèmes est en grande partie tributaire, tout d’abord, de l’originalité de la conception humanitaire du droit musulman. Cette convergence est ensuite, tributaire de la volonté qui a animé les concepteurs du droit international humanitaire de rechercher les dénominateurs communs entre les civilisations et d’élaborer des règles acceptables pour tous. Elle est, enfin et essentiellement, tributaire de l’effort de relecture et d’interprétation de l’institution du jihad, qu’ont entamé les jurisconsultes et les penseurs musulmans surtout depuis le XIXe siècle dans le but de limiter le jihad à sa vocation d’origine, soit la vocation défensive. Notre thèse n’abordera pas le sujet sous ses seuls aspects théoriques. Elle tentera, aussi, de comprendre et de jauger l’application de ce droit en se référant aux guerres menées par le prophète et ses compagnons durant les premiers siècles de l’Islam et de voir les implications de ce droit, ainsi que celles du droit international humanitaire contemporain, dans les conflits armés qui ont secoué le monde musulman, notamment ceux qui se déroulent actuellement en Irak, en Afghanistan, au Darfour soudanais et en Somalie. Cette thèse comporte trois parties. La partie introductive traitera du cadre général du droit international musulman. La deuxième partie sera consacrée à la détermination et à l’étude des facteurs qui ont permis la convergence entre les règles humanitaires du droit musulman et celles construites par le droit international humanitaire contemporain. La dernière partie de notre thèse consistera dans l’analyse des différents types de garanties et de protection que le droit musulman et le droit international humanitaire offrent aux populations civiles. En d’autres termes, cette partie sera le témoin de cette convergence et de cette parenté.

Orientadores : Yoshitaka Gushikem, Sandra C. de Castro
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Doutorado

L'histoire de l'identité trans et sa légalisation après la Révolution islamique de 1979 en Iran laisse souvent perplexe les observateurs étrangers. Chaque pays a sa propre façon d'accepter, d'ignorer ou de réprimer la demande de la transition de genre. Le rôle important du discours religieux sur la transition de genre en Iran est lié à la fatwa de l'ayatollah Khomeini, qui a sanctionné la réassignation sexuelle dans une société où toute identité non binaire et toute orientation non hétérosexuelle est un acte criminel. La fatwa a été publiée pour la première fois en 1967 et, après la révolution de 1979, dans les années 1980, cette fatwa a acquis soutien, financement et force dans la loi. Le discours juridique de la République islamique admet la possibilité d'une inadéquation entre le sexe et le genre et met à disposition les moyens médicaux pour guérir la souffrance de la personne trans. La catégorisation psychiatrique et le protocole médico-légal du changement de sexe constituent une réponse légitime à la « souffrance » chez les personnes trans. La souffrance en question fait référence aux sentiments d'un individu trans qui croit que son âme est « piégée dans le mauvais corps ». La légalisation de l'identité trans en Iran renvoie à des processus de biopouvoir où les technologies de genres sont au service d'un processus de normalisation de l'individu non binaire. Néanmoins, les individus trans utilisent leurs corps comme un outil de pouvoir pour actualiser leur propre définition du genre et de l'être genré. Nous analysons la construction iranienne des subjectivités trans dans une approche foucaldienne du pouvoir, du savoir et du sujet, dans trois domaines : (i) Le discours religieux qui légalise le changement de sexe, (ii) Le discours psychiatrique et légal qui catégorise l'identité trans en tant que « trouble de l'identité de genre » et (iii) Les réactions des individus trans au système. La corporéité du genre est un processus de « devenir » entre une autoconstruction identitaire de l'individu trans et la construction politico-légale des identités trans dans chaque société. Nous avons cherché à critiquer l'assujettissement du sujet en proposant d'autres modalités de l'interpellation non institutionnelles et non idéologique de l'individu trans en sujet trans. Ainsi nous avons essayé de redéfinir la transition de genre comme un « passage » dans un paradigme non pathologique inspiré par le concept de rhizome développé par Deleuze et Guattari et nous utilisons ce concept pour analyser la transition de genre et la possibilité de multiple forme d'identification. Le statut des personnes trans iraniennes se situe entre la pathologie et la résistance. L'individu trans construit son identité et transgresse les normes du genre. En s'orientant, en changeant, en choisissant, l'individu modifie inévitablement ce qu'il devient. Le corps dans cette transition est au cœur de la résistance trans dans son parcours de subjectivation. Les individus trans iraniens réagissent différemment au discours protocolaire de changement de sexe. Nous avons distingué les différentes modalités de réaction au protocole de changement de sexe que nous avons décrit en trois typologies de réactions chez les personnes trans. Le contexte sociopolitique de la société iranienne limite le transactivisme et les mouvements collectifs trans. Nous essayons d'introduire un type de résistance des individus trans iraniens qui ne soit ni une résistance révolutionnaire ou rebelle ni une résistance publique et collective. Nous développons le concept de « résistance quotidienne » qui décrit comment les personnes trans agissent dans leur quotidien de manière à porter atteinte au pouvoir. Pour enrichir notre analyse, nous avons suivi les activités théâtrales d'un acteur et metteur en scène trans qui sensibilise le public à travers ses performances
The history of trans identity in Iran and its legalization after the Islamic Revolution of 1979 often seems perplexing to outside observers. Each country has its own way of accepting, ignoring or repressing the gender transition. The important role of religious discourse on gender transition in Iran is related to the famous fatw' of Ayatollah Khomeini, which sanctioned sex change, in a society where any non-binary identity and non-heterosexual orientation is a criminal act. The fatwa was published first in 1967 and after the 1979 Revolution, in the 1980s, his fatwa gained support, finance and force of law. The legal discourse of the Islamic Republic, which accepts the possibility of inadequation between sex and gender and the medical means of remedying trans suffering, remains beholden to the binary notion of gender. Psychiatric labeling and the medico-legal protocol of sex change are a legitimating reply to trans individual "suffering". Here, the suffering in question refers to the feelings of an Iranian trans individual who believes that his/her soul is "trapped in the wrong body". A biopolitical analysis shows how mandatory sterilization manage bodies and their productive and reproductive capacities and roles in society by putting in concrete territories, the non-binaire bodies as threats to heterocentrist hegemony. Nevertheless, trans individuals use theirs bodies as a site of power, to actualize their own definition of gender binary and being. We analyze the Iranian construction of trans subjectivities by Foucault's concept of power, knowledge and subject in three domains: (i) The religious discourse which legalizes sex change, (ii) The power-knowledge discourse which categorizes trans identity as "gender identity disorder", and (iii) The trans individual reactions to the system. Embodying gender is a process of "becoming" between a trans self-construction and the politico-legal construction of trans identities in each society. The "wrong body narrative" then depends on the conversion of body and self-gender identity and the discursive production of gender binary norms in each society. We try to redefine gender transition as a "passage" in a non-pathological paradigm inspired by Deleuze and Guattari's concept of "rhizome" that we use for analyzing gender transition. Iranian trans individual's status is located beyond resistance and pathology. The trans individual builds his identity and intervenes, in addition, on the norms of the gender. By orienting oneself, by changing, by choosing, the individual inevitably modifies what they become. Bodies in this transition are the center of trans resistance as a process of subjectivisation. Iranian trans individuals react differently to the dominant gender discourse of the society. We made three typologies of trans subjectivities in reaction to legal protocol of sex change. The socio-political context of the society limits all kinds of transactivisme and trans movements. We try to introduce a special kind of resistance of Iranian trans individuals that is not a revolutionary or rebellious resistance, nor is it a public and collective one; it is closer to the concept of "everyday resistance" that describes how people act in their everyday lives in ways that might undermine power. We observed the activities of a trans performer who attempts to sensibilize society about trans identity

One of the pillars of phonological research has been the desirability of representing phonological processes as being local in application. Locality, as a principle of the grammar, constrains the relation between the trigger and target elements of a phonological process to one of adjacency. Adjacency, within the framework of Autosegmental Phonology and Underspecification theory, consists of two varieties: tier adjacency and structural adjacency (Myers (1987)). Tier adjacency examines linear relations among elements within an isolated tier of the representation (e.g. the tonal tier), while structural adjacency examines these relations mediated through the skeletal core, which organizes and maintains the linear relations between phonemes and their constituent elements. Locality and Adjacency are not, simply the preserve of featural relations and their skeletal core. The core itself, whether viewed as C/V slots, X/X' timing slots, or Root nodes, is organized into the grander structures of the Prosodic Hierarchy (e.g. syllable, Foot, etc.) . The formation of these units is a phonological process and as such subject to the same principles. A portion of the on -going debates in metrical theory has focused on whether metrical structure, in particular Foot structure, is limited to binary constituents. Kager (1989) proposes an extreme Binarism, with all metrical structure initially being limited to binarity. Hayes (1987) and Prince (1990) only commit to a strong preference for binary Feet. Halle & Vergnaud (1987) propose a system allowing binary, ternary, and unbounded Feet. The principle of Locality with its requirement of adjacency argues for a binary -view of metrical structure where the trigger and target of the structure building process are un- metrified elements. The most serious challenge to this view is the existence of languages which employ ternary constituents, e.g. Cayuvava, Chugach Alutiiq. These languages have been cited as evidence in arguing for a theory capable of generating ternary Feet. In a framework designed to maintain strict locality surface ternary constituents must be derived from underlying binary structures. This paper proposes a solution to this problem which relies on the ternary constituent being a complex constituent composed of a binary Foot grouped with an adjacent syllable. This constituent is not a Foot, but rather a Prosodic Word. Generating an iterative ternary Prosodic Word requires a new algorithm for building metrical structure. This algorithm builds metrical constituents in an opportunistic manner. Opportunistic building creates metrical constituents as soon as possible, instead of applying one particular structure building rule across the whole string before the next rule applies. This paper examines these issues through the metrical structures of the Alutiiq dialects described by Leer (1985a). The rich and detailed work of Leer serves admirably as a base for elucidating the issues of ternarity. Unfortunately, the ramifications of these proposals beyond the issue of ternarity can only be briefly alluded to in this paper. Length constraints do not permit me to present all aspects of these proposals in the full detail they require for their justification.

I take a critical view of sociopolitical and cultural issues dealing with homoeroticism andgay politics. I explore gender theories in order to further understand what it means to bemasculine or feminine and how it affects my placement in society. I use art as a tool forexpressing sexual freedom while questioning traditional sexual identity. I'm interested in exploring ideas of the oppressor and the oppressed, and how power becomes an inevitable force (in every society) that creates a hierarchy, consequently establishing control. But what is power? According to various definitions, power is an entity that possesses and or exercises authority or influence. I want to focus on this idea of exercising authority, which one can argue we need, but why? To prevent chaos or is it to control a society? What about exercising influence? Do we need an influence exercised upon us? Or does that make us subjected to another person's subjective point of views? These are questions that I directly or indirectly ask with my work in relationship to gender, gender roles, and sexual orientation. I am interested in Judith Butler's theory in performing gender, and how in performing gender, one assumes social hierarchy of power depending on what gender we are performing. If I am a man performing as a man then I am treated differently by society than if I am a woman performing as a woman. But what happens if I am a man performing as a man who prefers men as lovers, or a woman who prefers other woman as lovers? In what context is this situation accepted by our society? And is it different for men and women? And why? What does it mean to be a man? What does it mean to be a woman, within the context of performance? Then taking it a step further and argue that we are all performing subjective ideas constructed by social norms.

This thesis examines the creative cultural production, consumption and representation of individuals within Britain, classified as of ethnic minority backgrounds. It draws together the fields of 'race', ethnicity and nationality and argues that these wide ranging themes have been conflated to produce simplistic, inaccurate, understandings of contemporary identity categorisations. The thesis challenges these prescribed understandings and argues that they produce identity as situated within a binary perspective, British and Other. The need for an intersectional, relational perspective is outlined, not just for individuals but also when engaging communities. The thesis draws together two case studies to explore these issues. The first considered the research subjects' engagement with participatory arts practice within a youth centre setting in Coventry, UK. This case study highlighted the complexities of the cultural identities of those often marked as alterior. The second case study involved working with Asian women and young people in Birmingham to develop a visual arts exhibition, a publication and performance event. The case study particularly highlighted the ways in which people negotiated existing cultural institutions whose arts practice often moves towards an assimilationist agenda. Together the case studies provide a means by which the complexity of everyday life can be considered in relation to art, cultural production and representation. The thesis contributes to debates on culture, identity and art particularly in terms of public policy and how publicly funded cultural institutions fail to serve the needs and interests of ethnic minority communities within the UK. The thesis argues instead for the need to use arts and cultural practice to deconstruct binary perspectives, replacing them with intersecting cultural crossroads.

High-mass binary systems involve extreme environments that produce non-thermal emission from radio to gamma rays. Only three types of these systems are known to emit persistent gamma-ray emission: colliding-wind binaries, high-mass X-ray binaries and gamma-ray binaries. This thesis is focused on the radio emission of high-mass binary systems through interferometric observations, and we have explored several of these sources with low- and high-frequency radio observations, and very high-resolution VLBI ones. We have studied the gamma-ray binary LS 5039 at low and high frequencies, and we have determined its spectra and light-curves in the frequency range of 0.15—15 GHz by analyzing radio observations from the VLA, GMRT and WSRT. We have observed that its spectrum is persistent along the time on day, month and year timescales, exhibiting a turnover at 0.5 GHz. The obtained quasi-simultaneous spectra reveal subtle differences between them. Synchrotron self-absorption can explain the observed spectra, but the Razin effect is necessary at some epochs. This is the first time that this effect is reported in a gamma-ray binary. With all these data and a simple model, we have estimated the physical properties of the radio emitting region, providing an estimation of its size, the magnetic field, the electron density, and the mass-loss rate of the companion star. We have also explored the low-frequency emission of the gamma-ray binary LS I +61 303 through GMRT and LOFAR observations. We have detected for the first time a gamma-ray binary at a frequency as low as 150 MHz. We have also determined the light-curves of the source at 150, 235 and 610 MHz. These light-curves are modulated with the orbital and superorbital period, with a quasi-sinusoidal modulation along the orbital phase. The shifts observed between the orbital phases at which the maximum emission takes place at different frequencies have been modeled with a simple model, suggesting an expanding emitting region, with an expansion velocity close to the stellar wind one. The gamma-ray binary HESS J0632+057 has been explored with a very high-resolution EVN observation to unveil the evolution of its radio emission along the orbit. However, the source was not detected, setting an upper-limit which is one order of magnitude below the radio emission detected in previous observations. We have discovered a new colliding wind binary (HD 93129A) through a multiwavelength campaign with optical and LBA radio data. We have resolved the radio emission from the wind collision region, observing the expected bow-shaped structure. This source is one of the earliest, hottest, and most massive binary systems discovered up to now. We provide a rough estimation of the wind momentum rates ratio based on the observed structure. We have also observed an increase of the radio emission during the last years, as the system approaches to the periastron passage, which is estimated to take place in ~2024. Finally, we performed radio observations on two new sources that were hypothesized to be gamma-ray binaries. On one hand, the star TYC 4051-1277-1 was initially proposed to be associated with a non-thermal radio source, but he have concluded that the radio emission is originated by a quasar. On the other hand, MWC 656 has been discovered to be the first Be/BH binary system. However, its radio emission remains undetected. Based on these results, we have improved the knowledge of several high-energy binary systems through their radio emission, conducting for the first time detailed low-frequency estudies on these types of sources.
Las binarias de alta energía son sistemas que producen emisión de rayos X y/o rayos gamma, debido a la presencia de un entorno suficientemente energético como para acelerar partículas hasta velocidades relativistas. Sólo tres tipos de binarias han sido detectadas en rayos gamma de forma persistente: binarias con colisión de vientos, binarias de rayos X de alta masa o binarias de rayos gamma. Todas ellas involucran una estrella masiva (con una masa superior a 8 veces la masa solar) y a otra estrella masiva o a un objeto compacto. Esta tesis está centrada en el estudio de la emisión radio de estos sistemas a través de observaciones con radio interferómetros. Se han estudiado dos binarias de rayos gamma a bajas frecuencias (LS 5039 y LS I +61 303), obteniendo sus curvas de luz y espectros. Éstos nos han permitido determinar propiedades físicas de la región emisora, como el campo magnético, la tasa de pérdida de masa, o la velocidad de expansión de dicha región. También hemos revelado la presencia del efecto Razin en la parte absorbida del espectro de LS 5039, siendo la primera vez que se detecta en una binaria de rayo gamma. Además, se ha detectado por primera vez una binaria de rayos gamma, LS I +61 303, a una frecuencia tan baja como 150 MHz. También se ha estudiado la binaria de rayos gamma HESS J0632+057 con observaciones radio de muy alta resolución, aunque la misma no ha sido detectada. Se ha descubierto una nueva binaria con colisión de vientos, HD 93129A, a través de observaciones radio de muy alta resolución y observaciones ópticas. Por último, se han llevado a cabo observaciones radio de dos fuentes que eran candidatas a ser binarias de rayos gamma.

Recent years have seen an explosion in the number of eclipsing binaries containing white dwarfs. In the last few years the number of systems has increased from 7 to over 40, thanks mainly to large surveys such as the Sloan Digital Sky Survey and the Catalina Sky Survey. Many of these systems are survivors of the common envelope phase during which the two stars orbit within a single envelope which is rapidly thrown off through loss of energy and angular momentum. Detailed analysis of these systems can yield extremely precise physical parameters for both the white dwarf primary and its companion star. Stellar masses and radii are some of the most fundamental parameters in astronomy and can be used to test models of stellar structure and evolution. They can also be used to constrain the evolutionary history of the binary system offering us the chance to better understand the common envelope phase itself. In this thesis I present high-precision studies of several eclipsing post common envelope binaries. I use a combination of high-speed photometry and high-resolution spectroscopy to measure the masses and radii of both stars in each system. I compare these results to evolutionary models and theoretical mass-radius relations and find that, on the whole, the measured masses and radii agree well with models. However, the main-sequence companion stars are generally oversized compared to evolutionary models, although this deviation is much less severe at very low masses (< ∼ 0.1M⊙). I also find that the measured masses and radii of carbon-oxygen core white dwarfs are in excellent agreement with theoretical models. Conversely, the first ever precision mass-radius measurement of a low-mass helium core white dwarf appears undersized compared to models. Large scale surveys have also begun to identify double white dwarf eclipsing binaries. In this thesis I present a study of one of these systems and show the potential, as a double-lined spectroscopic binary, of measuring precise parameters for both stars in the future. Finally, I show that the mid-eclipse times of eclipsing binaries containing white dwarfs can be measured to a high enough precision that we can monitor them for evidence of period changes. I find that many systems show complex variations in their eclipse times and in many cases the only mechanism able to produce these changes is one or more sub-stellar objects in orbit around the binary. However, I show that care must be taken when attempting to detect planets in binary systems using eclipse timings.

This thesis focuses upon two different aspects of interacting binary stars, the study of the shortest period binary stars known V407 Vul and HM Cnc and the study of stochastic variability in cataclysmic variable stars. V407 Vul and HM Cnc are X-ray emitting stars with X-ray and optical light curves that are modulated on periods of 569 and 321 s, respectively. In chapter 4 we consider geometrical constraints upon the unipolar inductor model for these stars, in particular what parameter values (component masses, orbital inclination and magnetic colatitude) can describe the X-ray and optical light curves. We find that for a dipole field on the primary star, the unipolar inductor model fails to match the data on V407 Vul for any combin?tion of parameters, and can' only match HM Cnc if the sparser set of observations of this star have been unluckily timed. In chapter 5 we present optical light curves of V407 Vul and HM Cnc. The optical and X-ray light curves of HM Cnc have been reported as being in antiphase, but we find that in fact the X-rays peak around 0.2 cycles after the maximum of the optical light, as seen also in V407 Vul. The X-rayjoptical phase shifts are well explained under the accreting models of the systems if most of the optical modulation comes from the heated faces of the mass donors and if the X-ray emitting spots are positioned in advance of the mass donors, as is expected given the angular momentum of the accreting XIV l II , Supplied by The British Library - 'The world's knowledge' 1 material. Some optical emission may also come from the vicinity of the X-ray spot. and we further show that this can explain the non-sinusoidal light curves of HM Cnc. The only significant difference between the two stars is that V407 Vul is observed to have the spectrum of a G star. The variation in position on the sky of a blend of a variable and a constant star can be used as a measure of their separation. and is sensitive to values well below the limit set by seeing. We apply this 'pulsation astrometry' to deduce that .the G star is separated from the variable by about 0.027 arcsec and hence plays no role in the vadability of V407 Vul. We show that light travel time variations could influence the period change in V407 Vul if it forms a triple system with the G star. In chapter 6 we present the study of flickering. Flickering is a characteristic of accreting systems. It is thought that the maximum frequency present in an accretion disc is the dynamic frequency at the inner accretion disc radius. In cataclysmic variable stars this would appear as a break in the power spectrum on frequencies 0.01 - 3 Hz. We use the high speed CCD Camera ULTRACAM to obtain high time resolution data on 14 cataclysmic variables in the hope of seeing the expected break in their power spectrum. We did not find such a break because the power spectra of the cataclysmic variable stars observed was steeper than was expected. We measure a power spectrum proportional to j-2.5 while previous studies reported it to be proportional to j-2. We compared flickering in cataclysmic variable stars with stellar flares and concluded that they have the same colour behaviour so they have could the same origin Le. magnetic reconnection. We also compare the power spectra of cataclysmic variable stars and of X-ray binaries in the optical and concluded that the latter are much shallower than cataclysmic variable stars. We argue that this implies that flickering in X-ray transients comes from the inner accretion disc in both systems since their outer discs are thought to be similar. Supplied by The British Library - 'The world's knowledge'

In fantasy literature, representations of gender and sexuality outside of the heteronormative binary have historically been limited. Although queer fantasy is on the rise, depictions of non-conformational identities are still rare and far in-between. This thesis seeks to examine one of the earlier fantasy representations of a queer character, the non-binary Beloved in Robin Hobbs fantasy series The Realm of the Elderlings in terms of gender and sexuality. Throughout the series, Beloved assumes different identities of various genders and sexual orientations, and continuously claims that these are all equally true and valid representations of themselves, although these are distinctly separated by ways of, often gendered, physical attributes. Therefore, a central part of this thesis will be to examine how these shifts between genders and sexual identities are established performatively, something I will do with the support of Judith Butler’s theory of gender performativity as it is presented in Gender Trouble. While the text ultimately lends itself to a reading in Beloved’s favour, they are often othered and met with scorn from other characters of the series, something that is quite central to their characterization. Consequently, this thesis will also investigate these reactions and the often heteronormative and conservative stances they demonstrate, and, most notably, how these reactions mirror exterior societal attitudes and change in accordance with these.

Gamma-ray binaries are systems that comprise a young, massive star and a compact object that can be either a young pulsar or a black hole. They emit radiation from radio up to tens of TeV and show flux variability along the whole electromagnetic spectrum. For three of the four detected gamma-ray binaries, the nature of the compact object is unknown. In this thesis we present a study of gamma-ray binaries through three approaches that involve the simultaneous study of these sources in X-rays and very high energy (VHE) gamma-rays. We present the discovery of correlated X-ray and VHE gamma-ray emission from LS I +61 303. The correlations indicates that the emission from these two bands could be originated in the same parent particle population, and we explore this idea through the calculation of a radiative model. This model allows us to significantly constrain the physical properties of the non-thermal emitter in LS I +61 303. For those systems where the compact object is a young pulsar, the interaction between the stellar and pulsar winds will give rise to strong shocks. The shocked pulsar wind is the candidate location for non-thermal emission from these systems. The shocked stellar wind should give rise to a thermal X-ray spectrum, but no such features have been detected in the X-ray spectrum of gamma-ray binaries. We present a model of the thermal emission of the shocked stellar wind and use it to constrain the pulsar properties. We have applied this method to two X-ray observations of LS 5039 and have successfully constrained the pulsar spin-down luminosity. Finally, we present a search for VHE emission from Scorpius X-1 through a simultaneous X-ray and VHE gamma-ray campaign. The X-ray observations allowed us to select black-hole states where non-thermal X-ray emission has been detected. We did not find significant VHE emission in any of the black hole states, but the upper limits derived will prove useful in future modelling of the non-thermal emitter in the source.
Les binàries de raigs gamma són sistemes binaries formats per una estrella jove i massiva i un objecte compacte, que pot ser un púlsar jove o un forat negre, que emeten radiació fins a desenes de TeV i mostren variabilitat orbital en totes les bandes d'emissió, des de radio fins a raigs gamma. En el cas de tres de les quatre binàries de raigs gamma detectades avui dia, se'n desconeix la natura de l'objecte compacte. En aquesta tesi presentem un estudi de les binàries de raigs gamma mitjançant tres treballs complementaris que involucren l'estudi simultani d'aquestes fonts en raigs X i raigs gamma de molt alta energia. En primer lloc presentem el descobriment d'emissió en raigs X i raigs gamma de molt alta energia correlades en el temps al sistema LS I +61 303. Aquesta correlació ens indica que l'emissió en les dues bandes pot provenir d'una única població d'electrons, i ho confirmem mitjançant la realització d'un model teòric de radiació que ens permet restringir significativament les propietats físiques de l'emissor no tèrmic de la font. En cas que la font energètica dels sistemes sigui un púlsar, la interacció entre els vents de l'estrella i el púlsar dona lloc a una regió d'interacció on el vent xocat del púlsar accelera partícules i emet des de radio fins a raigs gamma. A l'espectre de raigs X, però, no es detecta l'emissió tèrmica del vent xocat de l'estrella, que s'escalfa fins a desenes de milers de graus. Això ens ha permès estudiar la forma de la regió d'interacció, determinada principalment per la potència del púlsar, i fer un càlcul teòric de l'emissió en raigs X tèrmics. Hem aplicat aquest model al sistema LS 5039 i hem pogut determinar la potència del púlsar, fet important per a la modelització de l'emissió no tèrmica de la font. Finalment, presentem la cerca d'emissió de raigs gamma provinent de sistemes binaris fins ara no detectats. Una campanya simultània en raigs X i raigs gamma ens va permetre seleccionar les dades de molt alta energia del microquàsar Sco X-1 en funció de l'estat d'acreció sobre l'objecte compacte. Tot i no detectar la font en raigs gamma, els límits superiors obtinguts permeten restringir les propietats físiques de Sco X-1 rellevants per a l'emissió en molt alta energia.

Etude d'etoiles de type a-f au voisinage solaire, de noyaux brillants de nebuleuses planetaires et des sous naines les plus brillantes. On s'interesse plus specialement a leur repartition galactique: jeune disque, vieux disque, halo. Les relations theoriques entre binarite, rotation, pulsation et structure d'enveloppe chez les etoiles a-f ont ete confirmees par analyse statistique. Un noyau a spectre composite a ete decouvert dans la nebuleuse planetaire lts et des variations d'eclat periodiques decelees dans le noyau abell 35. Six nouvelles binaires spectroscopiques ont par ailleurs ete decouvertes parmi les sous naines brillantes du halo

This thesis reports photometric and spectroscopic studies of three close binary systems; BP Velorum, V392 Carinae and V752 Centauri. BP Velorum, a W UMa-type binary, was observed photometrically in February 2007. The light curves in four filters were fitted simultaneously with a model generated in the eclipsing binary modeling software package PHOEBE. The best model was one with a cool star spot on the secondary larger component. The light curves showed additional cycle-to-cycle variations near the times of maximum light which may indicate the presence of star spots that vary in strength and/or location on a time scale comparable with the orbital period, (P = 0.265 d). The system was confirmed to belong to the W-type subgroup of W UMa binaries for which the deeper primary minimum is due to an occultation. V392 Carinae, a detached binary with an orbital period of 3.147 d, was observed photometrically by Michael Snowden in 1997. These observations were reduced and combined with the published light curve from Debernardi and North (2001). High resolution spectroscopic images were taken using the University of Canterbury's HERCULES spectrograph. The radial velocities measured from these observations were combined with velocities from Debernardi and North (2001). The radial velocity and light curves were fit simultaneously, confirming that V392 Car is a detached system of two main sequence A stars with a mass-ratio of 0.95. The derived systematic velocity is consistent with V392 Car being a member of the open cluster NGC 2516. The W UMa-type binary V752 Centauri was observed photometrically and spectroscopically during 2007. The high resolution spectra displayed weak sharp lined features superimposed over the strong broad lined spectrum expected from the 0.370 d contact binary. Fourier methods were used to separate the broad and sharp spectral features and radial velocities for each were measured by cross-correlation. A fit to the photometry and radial velocities for the contact binary implied a system of two late F stars with a mass-ratio of 3.38 in an over-contact configuration. The derived systematic velocity (−13.8km/s), has changed significantly from the 1972 value (29.2km/s). The third (sharp lined) component's radial velocities were measured and found to have a period of 5.147 d, semi-amplitude of 43.4km/s and systematic velocity of −7.3km/s. The likely configuration of the entire system is that of a contact binary in a long period orbit about a lower mass detached binary. V752 Cen is thus a triple lined spectroscopic quadruple.

The study of spectroscopic binaries is by no means a new area of study. The Doppler shifting of spectral lines as the stars orbit around each other is now able to be measured very precisely. Binary stars give a reliable means of determining stellar parameters such as the mass. A star's mass is one of the most dominant factors in determining its evolution. Stars for study in this thesis were selected from SB9 (the ninth catalogue of spectroscopic binaries). They were chosen on criteria such as apparent visual magnitude, orbital period, orbital solution grade, equatorial velocity and position. Only stars with poor to average orbital solutions were chosen as it is these orbits which need the most work done. In total 6 spectroscopic binary systems were chosen for study in this thesis. Four single lined spectroscopic binaries (HD 70958, HD 110318, HD 122223 and HD 141544) and two double line spectroscopic binaries (HD 110317 and HD 148704). Unfortunate observing conditions meant that adequate phase coverage of HD 110317 and HD 110318 was not achieved. Adequate phase coverage of the star HD 122223 was also not achieved but this is likely a result of the period being about three years and not about 207 days as quoted in the catalogue. Observations were carried out with the HERCULES spectrograph and the 1-metre McLellan telescope at the Mt John University Observatory from December 2007 until September 2008. Radial velocities were than measured from these spectra with HRSP3 and then orbital solutions were derived. Orbital solutions have been derived for the single-lined systems HD 141544 and HD 70958. The precision of HD 141544 was much better than HD 70598. This is because HD 70958 is complicated by differential rotation and possible chromospheric activity. The orbital solution of the double lined system HD 148704 was obtained by using CARTopt and not TODCOR as is common, with good results. HD 122223 is included even though only six spectra were obtained as it will be evident that the current orbital solution should be rejected in favour of the previous solution obtained in 1936 by Christie. Although the amount of data was not as large as was hoped, significant improvements of the orbital solutions were obtained. The secondary component of HD 148704 had only previously being detected in a very few spectra but now has a good orbital solution. Errors on all parameters have been decreased and tighter limits have been placed on the secondary components of the single lined systems. The mass ratio of the components of HD 148704 was also determined very accurately and calculation of the inclination from photometry may allow accurate masses to be determined.

The launch of the Fermi Gamma-ray Space Telescope marked a new era in observing gamma-rays from astrophysical sources. Fermi’s high sensitivity in the ~ 0.1−300GeV energy range opens an important window in the observation of the gamma-ray emissions from pulsar binaries, which emit most of their radiation energy in the gamma-ray range. We can now observe the gamma-ray emissions from pulsar binaries at an unprecedented accuracy, and investigate their origin in detail. In this thesis, we present the studies on two systems of pulsar binary of two distinct classes. The gamma-ray emissions from the high-mass gamma-ray binary LS 5039 were studied using the latest data from Fermi. The emission is modulated according to the 3.9 hr orbital period of the system. The results can be explained by the contribution of three components: the pulsar magnetospheric emission, the pulsar wind emission and the emissions from the shock formed from the interaction between the pulsar wind and companion’s stellar wind. The results were compared with observed data from Fermi and also in X-ray and TeV. In addition, the emissions from the millisecond pulsar PSR J1023+0038 and its low mass binary companion were also studied. This system recently went through a transition from the rotation-powered state to the accretion state, after going the opposite way in 2007. This state transition, discovered through the disappearance of radio pulsation, was accompanied by the brightening in GeV, X-ray and UV fluxes. A detailed Fermi observation was performed, supplemented by multi-wavelength observations. It was found that the emission from this system can also be described by the emissions from the pulsar magnetosphere, the pulsar wind and its shock. These two systems, although of distinct classes of pulsar binaries, provide complementary cases for the study of high-energy radiation processes in pulsar binaries.
published_or_final_version
Physics
Master
Master of Philosophy

Large software projects contain significant code duplication, mainly due to copying and pasting code. Many techniques have been developed to identify similar code to enable applications such as refactoring, detecting bugs, and detecting illicit code reuse. Because source code is often unavailable, especially for third-party software, finding similar code in binaries becomes particularly important. Unfortunately, binaries present challenges that make it difficult to detect similar code, such as overcoming the lack of high-level information and piercing the veil of compiler optimizations. Due to these difficulties, we are yet to have practical techniques and tools for binary similarity detection.

This dissertation presents novel research that tackles these challenges toward realizing practical binary similarity detection. The central focus of the work is on automatically extracting syntactic and semantic signatures directly from the binaries. This dissertation presents a family of related algorithms, frameworks and tools for extracting these signatures. The two main tools presented are a binary clone detection tool for syntactic similarity and S

LEUTH

, a tool that detects software license violations using hybrid semantic and syntactic signatures. Although software license violations are common, they often remain undetected due to challenges inherent in binary similarity detection. Examples of software license violations include code a programmer wrote for an ex-employer or open source software licensed under copy-left (such as the Linux kernel reused in a closed source router). Each presented algorithm or tool is practical, automatically finding fine-grained similarity with high precision.

This dissertation also introduces a general, mixed binary interpretation framework and its accompanying implementation for realizing the aforementioned work.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2011.
Cataloged from PDF version of thesis.
Includes bibliographical references.
In this thesis, I present work from three separate research projects associated with observations of X-ray binaries. Two of those revolve around spectral characteristics of neutron star low-mass X-ray binaries (NS-LMXBs), with a particular source, XTE J1701-462, playing a central role. First, I construct and study color-color and hardness-intensity diagrams (CDs and HIDs) for a large sample of NS-LMXBs using Rossi X-ray Timing Explorer (RXTE) data spanning ~15 years. I study in particular detail three sources whose complicated CDs/HIDs are strongly affected by secular motion -- Cyg X-2, Cir X-1, and GX 13+1 -- and show that Cyg X-2 and Cir X-1 display CD/HID evolution with strong similarities to the transient Z source XTE J1701-462, which was previously shown to have evolved through all subclasses of NS-LMXBs as a result of changes in mass accretion rate. I build on the results for XTE J1701-462, Cyg X-2, and Cir X-1 and rank all the sources in the sample based only on their CD/HID morphology. I speculate that this represents a rough ranking in terms of the relative ranges in mass accretion rate experienced by the sources. Next, I use data from RXTE, Swift, Chandra, and XMM-Newton to study the transition to quiescence and the first ~1200 days of the quiescent phase of XTE J1701-462 following the end of its extraordinarily luminous 19 month outburst in 2006-2007. I find that the crust of the neutron star cooled rapidly during the first ~200 days of quiescence, after having been heated out of thermal equilibrium with the core during the outburst; the source has subsequently shown slower cooling along with sporadic low-level accretion activity. I discuss the implications of the observed cooling behavior and low-level accretion, the former of which yields information on the internal properties of the neutron star. Finally, I use multiple Chandra observations to study the X-ray source populations in the late-type galaxies NGC 6946 and NGC 4485/4490. A particular emphasis is placed on investigating the long-term variability of the sources, several of which are ultraluminous. I present detailed source catalogs and characterize the populations -- which consist primarily of X-ray binaries -- using X-ray luminosity functions and CDs.
by Joel Karl Fridriksson.
Ph.D.

This study examines the term beur as well as the category it defines, both in terms of individuals who identify as beur, and the genre of literature that stems from the beur population in contemporary France. I begin by first suggesting that the notion of beur as a category and label serves as a third space in the binary of French culture and Maghrebi culture. This third space is necessary as the children of Maghrebi immigrants in France find themselves in between each culture and the sphere of influence that follows. The term is then problematized. The theme of binaries and the third spaces that emerge because of the problematic nature of the binaries is recurring throughout my study. I explore what these third spaces are by examining four contemporary French novels: Faïza Guène’s Kiffe kiffe demain and Un homme ça ne pleure pas, Ahmed Djouder’s Désintégration, and Brahim Metiba’s Ma mère et moi. The characters in each of these works struggle with their identity as they forge their own third spaces as solutions to various binaries that they discover they cannot fit into. In my study, I demonstrate this in three realms: integration and engaged citizenship; familial relationships, primarily parent-child relationships and the generational difference that further complicates pre-existing cultural difference; and gender roles. Each of the narratives and the main characters conveys the problematic nature of viewing French and Maghrebi culture in a binary. In my explication of the text, I argue that each narrative works towards the creation of a new third space in varying ways.
Master of Arts

This thesis describes a numerical study of binary boson stars within the context of an approximation to general relativity. Boson stars, which are static, gravitationally bound configurations of a massive complex scalar field, can be made gravitationally compact. Astrophysically, the study of gravitationally compact binaries---in which each constituent is either a neutron star or a black hole---and especially the merger of the constituents that generically results from gravitational wave emission, continues to be of great interest. Such mergers are among the most energetic phenomena thought to occur in our universe. They typically emit copious amounts of gravitational radiation, and are thus excellent candidates for early detection by current and future gravitational wave experiments. The approximation we adopt places certain restrictions on the dynamical variables of general relativity (conformal flatness of the 3-metric), and on the time-slicing of the spacetime (maximal slicing), and has been previously used in the simulation of neutron stars mergers. The resulting modeling problem requires the solution of a coupled nonlinear system of 4 hyperbolic, and 5 elliptic partial differential equations (PDEs) in three space dimensions and time. We approximately solve this system as an initial-boundary value problem, using finite difference techniques and well known, computationally efficient numerical algorithms such as the multigrid method in the case of the elliptic equations. Careful attention is paid to the issue of code validation, and a key part of the thesis is the demonstration that, as the basic scale of finite difference discretization is reduced, our numerical code generates results that converge to a solution of the continuum system of PDEs as desired. The thesis concludes with a discussion of results from some initial explorations of the orbital dynamics of boson star binaries. In particular, we describe calculations in which motion of such a binary is followed for more than two orbital periods, which is a significant advance over previous studies. We also present results from computations in which the boson stars merge, and where there is evidence for black hole formation.

Thesis (Ph. D.)--University of California, San Diego, 2008.
Title from first page of PDF file (viewed September 4, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 204-213).

Close binaries containing compact objects come in many different forms, but have one thing in common: their evolution involves at least one common envelope phase and angular momentum losses. However, many aspects of these two fundamental processes are still poorly understood. Ample observational input holds the key to improving our understanding, as only then can theoretical models be properly calibrated and tested. Close binaries containing a white dwarf are perhaps the best-suited class of objects to provide such input, due to their ubiquity. White dwarf binaries that additionally display eclipses are of added interest, as accurate and model-independent determinations of fundamental stellar parameters, such as the masses and radii of the binary components, can only be obtained in such systems. In this thesis, I present a study of eclipsing white dwarf binaries. I identify SDSSJ 0110+1326, SDSSJ 0303+0054, SDSSJ 1210+3347, SDSSJ 1435+3733 and SDSSJ 1548+4057 as new eclipsing, detached, post-common-envelope, white dwarf +M-dwarf binaries. I use follow-up photometric and spectroscopic observations, as well as a light curve fitting technique to measure their orbital periods, and derive the masses, radii and radial velocities of the binary components. These five systems have been identified as part of the first dedicated search for eclipsing post-common-envelope binaries and almost double the existing population. The measurements of the stellar parameters, and others obtained from similar systems, are of great value both for the calibration of the common envelope equations and for testing the mass-radius relations of white dwarfs and low-mass main sequence stars. I also identify HS 2325+8205 as a new eclipsing and very frequently outbursting dwarf nova. Combined constraints from photometric and spectroscopic observations are used to infer the binary and stellar parameters. The combination of eclipses, frequent outbursts, brightness range and high declination make HS 2325+8205 an ideal laboratory for detailed studies of accretion discs and accretion processes in close binaries. Finally I study the cataclysmic variable V455And, in an attempt to verify the presence of non-radial pulsations in the white dwarf primary. This is achieved by analysing ten-years worth of photometric observations using time-series analysis techniques and Fourier transforms. The results are indeed consistent with white dwarf pulsations, although a very complex behaviour of the power spectra is revealed, most likely a result of the rapid rotation of the accreting white dwarf primary.

It has become increasingly clear that many binary systems will pass through a common envelope stage at some point during their evolution. For short period systems composed of main-sequence 0 and early B stars this stage will probably occur for the first time towards the end of hydrogen-core burning in the primary component (case A evolution) rather than during the transition to the giant stage (case B evolution). If masses, radii, luminosities, temperatures and orbital parameters were well determined for a good sample of those systems, it could be established whether the individual components were so close that case A evolution was inevitable or whether the primary component had enough room to complete its main-sequence phase before reaching its Roche. limit and hence case B evolution. The latter mode has been studied extensively (both conservatively and non-conservatively) whereas the reception of matter by the secondary component in the rapid mass-transfer phase of case A evolution has only very recently been investigated. It is still one of the principal problems impeding further progress on this scenario. To resolve this situation and provide observational material with which to compare these theoretical models, an observing program was established to study systems of spectral type earlier than B5 and of orbital period of less than 1.8 in both the Northern and Southern Hemispheres. Light curves were obtained at St Andrews using the newly-refurbished Twin Photometric Telescope and analysed using software developed specifically for this instrument. Further spectroscopic and photometric data were obtained at La Palma SAAO, Sierra Nevada and Boyden. Analyses of these spectroscopic and photometric observations have provided the necessary physical parameters to determine the evolutionary status of these systems. The systems observed were AH Cephei and V1182 Aquilae which are shown to be detached systems, TT Aurigae, SX Aurigae and AI Crucis which are all semi-detached systems and V701 Scorpii and HZ Pyxidis which are contact systems. Accurately-determined parameters of 14 stars have been found, including four 0 stars in detached systems. Therefore-the number of stars with well-determined masses of greater than 30M has been increased by 25%. It is clear from this study that case A mass transfer will play and has played an important role in the evolution of five out of the seven systems. It is debatable whether or not the contact systems have passed through a mass transfer phase, particularly RZ Pyx. The evolutionary history of this system is of particular interest, especially if this binary was in a marginal contact configuration when it arrived on the main sequence. Attempts have been made to look for intrinsic variability in these systems but no periodic variation has been found in any of them. If such a phenomenon exists in one of the components of the binaries in the sample then it must have an amplitude of less than 0.01. The comparison of the physical parameters of 67 stars compiled by the author from this work and from published data with theoretical zero-age and terminal-age main sequences shows that traditional modelling of semi-convection without mass loss is not adequate. Convective overshooting and mass loss play a very important role in the evolution of massive close binary systems of short period.

An introduction is given to the fields of X-ray and cataclysmic binaries, low mass X-ray binaries (LMXBs) and globular clusters. New observations of the W Vir star AC5 (=V86) are used show that it is probably the source of Hα emission previous authors have found in core of the globular cluster M15. The first phase resolved optical spectroscopy of AC211, the optical counterpart of the X-ray source in M15, are presented, and its binary period discovered to be 9.l±0.5 hours. A re-analysis of archive ultraviolet (UV) spectra of M15, shows spectral features which are attributed to AC211. These observations are combined with those of other authors, to prove AC211 is probably an "accretion disc corona" (ADC) source. After reviewing the superoutbursts of the SU UMa class of dwarf novae, X-ray, UV, optical and infrared observations of the SU UMa star OY Car are used to show that during superoutburst there is extensive vertical structure in its accretion disc, similar to that in the ADC and "dipping" LMXBs. Archive UV data from the 1978 outburst of WZ Sge shows that it had similar vertical structure. UV observations presented of EX Hya during a bright outburst may have the same explanation. From the OY Car data, a temperature and area for the region which produces the "superhump" light are derived, of 8 OOOK and ^-10²⁰cm², respectively. It is found that during OY Car's superoutburst, the size of the 0-C variations of the eclipse timings are significantly smaller than was previously thought, and that it has an extended X-ray source whose size is comparable to the binary separation. The results are discussed with respect to models of the superhump phenomena in SU UMa stars, and possible causes of vertical disc structure in X-ray and cataclysmic binaries.

This thesis is a study of the X-ray binary Cygnus X-3, and related objects, using primarily observations at radio, sub-rom and infrared wavelengths. I find the emission mechanism to be synchrotron in the radio and sub-mm, while the infrared emission is thermal from the hot wind. The upper limit to the synchrotron emission is interpreted as being due to spectral ageing and implies a magnetic field strength of 7 T at a distance of 700 R0 from the centre of the system. The nature of the companion star in Cyg X-3 was investigated by midinfrared observations using the ISO satellite. I find that the spectrum shows a steady decrease and flattening at longer wavelengths which is consist ant with a standard wind emission. Thus the complete quiescent spectrum from Cyg X-3 shows two different emission mechanisms and covers a full 5 decades of frequency. High sensitivity and high time resolution radio photometry, taken during a minor flare period, reveal rapid (10 minute) increases and decreases in intensity which severely constrain the size of plasmons. Brightness temperatures of typically 10 10 K are found. I also consider models for the superluminal expansion and contraction of the Cyg X-3 source, observed on a milli-arcsecond scale by LIewell et al. (1998). The elliptical shape and the superluminal contraction are particularly hard to explain. Models involving photon beams illuminating shells, or propagating photon patterns are the most plausible. A thorough survey for maser emission from these sources has produced strong upper limits and improved our understanding of the circumstellar environment ofCyg X-3. This thesis has probed the radio-jet X-ray binaries, and made significant advances, opening up more questions about the nature of these sources and new areas of research.

In the past few years, there has been increased interest in automating the reverse engineering and verification of binary executable code. The importance of this subject has b,een highlighted by the growing relevance of security, of reliability and of legacy code. Since dynamic analysis is of limited use for whole-program analyses, there has been a renewed enthusiasm for the development of automated static analyses, which can prove a property holds over all paths of the program. The abstract interpretation framework serves this purpose and has been widely adopted in both academic and industrial circles. Yet, since its introduction in 1977, standard abstract interpretation has been formulated as the least solution of a set of fixpoint equations. The work in this thesis deviates from the standard approach to static analysis, proposing that recent advances in decision procedures could be leveraged to tackle the problem. The thesis can be considered to be a survey of the application of Boolean satisfiability (SAT) and linear optimisation to the problem of static analysis, specifically range analysis of binary executable code. It is shown (with experimental results) that SAT and linear optimisation can be used to infer ranges of register values which, amongst others, are useful for control flow recovery and for detecting binary vulnerabilities, such as buffer and heap overflows.

Orientador: Maria Aparecida Silva
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-07-28T22:58:14Z (GMT). No. of bitstreams: 1 Souza_FabianodoValede_M.pdf: 3561550 bytes, checksum: f3b4f61836648dece8c995dd128d26c3 (MD5) Previous issue date: 2001
Resumo: O conhecimento das propriedades fisicas dos materiais é de fundamental importância na caracterização de sólidos e de misturas de sólidos. As misturas de sólidos têm sido utilizadas cada dia mais em processos industriais, visando aprimorar as propriedades de interesse relativas a um material, como capacidade de adsorção e tempo de secagem. Este trabalho visa determinar varias propriedades físicas de dois sólidos, o Caulim e a Zeólita NaY, bem como a mistura destes dois sólidos, caracterizando estes materiais para que eles possam ser aplicados em processos industriais de uma forma mais eficiente. O objetivo do trabalho é apresentar equações que relacionem as propriedades dos materiais puros com as propriedades de suas respectivas misturas através das frações mássica e volumétrica das amostras. Desta forma, apenas a caracterização dos materiais puros seria suficiente para predizer as propriedades físicas de uma mistura binária ou de um sólido composto por três ou mais componentes. Outro objetivo do trabalho é apresentar valores confiáveis para que estes possam ser utilizados no estudo do transporte de massa no interior dos poros do material. Os aparelhos picnômetro de Hélio e porosímetro de Mercúrio foram utilizados na determinação das densidades real e bulk, e também na determinação da porosidade dos sólidos utilizados neste trabalho. A partir dos dados obtidos na porosimetria de Mercúrio e da equação de Wasburn, também foi possível a determinação das permeabilidades intrínseca e relativa das amostras. O método clássico de obtenção das isotermas de dessorção foi utilizado, onde os resultados foram aplicados nas equações de Kelvin e BET para a determinação da área superficial e da fração de microporos presente nas amostras. Finalmente, a distribuição de tamanho de partícula foi realizada para o Caulim e para a Zeólita Na Y através do Contador Coulter, para uma análise de como as partículas destes dois materiais se arranjam entre si. As equações propostas produziram curvas que estão de acordo com os resultados experimentais obtidos neste trabalho. Todas as propriedades fisicas puderam ser reproduzi das com as equações propostas, especialmente a área superficial especifica das partículas e a fração de microporos, onde a concordância com os resultados experimentais foi praticamente total
Abstract: The knowledge of the materials physical properties is specially important in the characterization of pure solids and mixtures. The solids mixtures have been used frequent1y in industriaI processes to improve the properties of interest of a material, as capacity of adsorption and drying time. This work aims to determine some physical properties of two solids, Kaolin and Zeolite Na Y, as well as of mixtures of these two solids. With this characterization, these materials wiIl be able to be applied in industrial processes with a better efficiency. The objective of the work is also to present equations that relate the properties of the pure materiais with the properties of their respective mixtures through the mass and volumetric fractions of the samples. In this way, only the characterization of the pure materials would be enough to predict the physical properties of a binary mixture or of a solid hold for three or more components. Another objective is to present reliable results so that these results can be used in the study of mass transport in the pores of materiais. The picnometer and mercury porosimeter had been used to determine the real and bulk densities, and also to determine the porosity of solids used in this work. From the data gotten in the porosimeter and using the equation of Washburn, the determination of the intrinsic and relative permeabilities of the samples was possible. The classic method to draw the desorption isotherms was used, where the results had been applied in the Kelvin and BET equations to determine the specific surface area and the fraction of micropores in the samples. Finally the particle size distribution was determined for the Kaolin and Zeolite Na Y with a Coulter Counter, for an analysis of how the particles of these two materials could be arranged between themselves. The derived equations had drawn curves that are in agreement with the experimental data gotten in this work. AlI the physical properties could be reproduced with the derived equations, especially the solid specific surface area and the fraction of micropores, where the agreement with the experimental results was practically total
Mestrado
Engenharia de Processos
Mestre em Engenharia Química

High Mass X-ray Binaries (HXMBs) are some of the brightest objects in the X-ray sky and test our understanding of accretion physics in extreme stellar environments. In this thesis, characterisation of the accretion processes around periastron in two Supergiant Fast X-ray Transients (SFXTs) and one Be/X-ray Binary (BeXRB) is presented. A combined XMM-Newton and INTEGRAL study of the SFXT SAX J1818.6-1703 reveals the source to be in an active state, presenting a low luminosity phase that can be explained by the onset of a subsonic propeller or transition to the radiative regime of quasi-spherical accretion (QSA). The strongest flaring activity coincides with significant spectral hardening and the associated luminosities of this phase suggest a potential transition to the Compton regime of QSA. Spectral analysis also reveals strong intrinsic absorption, an order of magnitude higher than previously observed and among the highest measured in an SFXT. Observations of the SFXT IGR J18450-0435 with XMM-Newton also show low luminosity phases that can be explained by the onset of the radiative regime of QSA. Fast flaring behaviour is attributed to transition to the Compton regime and evidence of the accretion of magnetised stellar wind is presented. Spectral analysis again reveals enhanced local absorption up to five times greater than previous reported. A multi-wavelength study of the BeXRB IGR J01217-7257 allows the discovery of X-ray periodicities of 82.5±0.7 days and 2.1562±0.0001 seconds attributed to the neutron star orbital and spin periods respectively. Detected X-ray outbursts are put into an orbital context and found to be consistent with Type-I outbursts. Analysis of long-baseline optical data reveals short periodicities (∼ 1 day) that are attributed to non-radial pulsations (NRPs) of the companion and an association between the NRPs, decretion disc growth and the onset of Type-I outbursts is suggested.

Central star binarity is often invoked as the main driver behind the shaping of aspherical planetary nebulae, however observational support for this hypothesis is lacking. This work presented in this thesis attempts to observationally test this theory by investigating the relationship between central star binarity and nebular morphology for several planetary nebulae. The discovery of six new binary central star systems is also reported. A detailed spatio-kinematical analysis of Abell 41 was performed, showing the nebula to have a bipolar morphology waisted by a toroidal structure, the symmetry axis of which is found to be perpendicular to the plane of the central binary. This alignment is exactly as predicted, indicating that the central binary, MT Ser, has played a significant role in shaping Abell 41. This is only the second planetary nebulae to have had this link, between binary and nebular inclination, explicitly shown. A spatio-kinematic model has been developed for ETHOS 1, indicating that its spectacular polar outflows are kinematically older than the central region of the nebula. This finding is discussed in the context of binary evolution, and it is concluded that the polar outflows in these nebulae are probably formed before their central binaries have entered the common-envelope phase. The central star of ETHOS 1 has yet to be the subject of detailed study, and as such, the orientation of the nebula could not be compared to that of its central binary. A spatio-kinematical analysis of SuWt 2 is presented, proving that the nebular ring is in fact at the waist of a much larger, extended bipolar structure. SuWt 2 is not known to contain a post-main sequence central star, required to eject and ionise the nebular shell, but rather a double A-type binary. The results of the analysis are discussed with relation to possible formation scenarios for SuWt 2. It is concluded that, while neither component of the double A-type binary could be the nebular progenitor, the presence of a third component to the system, which would have been the progenitor, cannot be ruled out. However, as there is no evidence that the central star of SuWt 2 is a binary alone, it is suggested that SuWt 2 should be removed from future lists of planetary nebulae known to host a binary central star. A sample of sixteen central stars of planetary nebulae, displaying morphological traits believed to be typical of central star binarity, were monitored for signs of periodic photometric variability associated with binarity. Six new photometrically variable close-binary stars were discovered, representing a ~15% increase on the previously known figure. The binary detection success rate from this investigation is compared to that of other surveys, and it is concluded that, while the results are promising, a more rigorous test is required to fully assess the extent to which specific morphological traits can be used as indicators of central star binarity.

Code obfuscation techniques are increasingly being used in software for such reasons as protecting trade secret algorithms from competitors and deterring license tampering by those wishing to use the software for free. However, these techniques have also grown in popularity in less legitimate areas, such as protecting malware from detection and reverse engineering. This work examines two such techniques - packing and virtualization-obfuscation - and presents new behavioral approaches to analysis that may be relevant to security analysts whose job it is to defend against malicious code. These approaches are robust against variations in obfuscation algorithms, such as changing encryption keys or virtual instruction byte code.Packing refers to the process of encrypting or compressing an executable file. This process "scrambles" the bytes of the executable so that byte-signature matching algorithms commonly used by anti-virus programs are ineffective. Standard static analysis techniques are similarly ineffective since the actual byte code of the program is hidden until after the program is executed. Dynamic analysis approaches exist, but are vulnerable to dynamic defenses. We detail a static analysis technique that starts by identifying the code used to "unpack" the executable, then uses this unpacker to generate the unpacked code in a form suitable for static analysis. Results show we are able to correctly unpack several encrypted and compressed malware, while still handling several dynamic defenses.Virtualization-obfuscation is a technique that translates the original program into virtual instructions, then builds a customized virtual machine for these instructions. As with packing, the byte-signature of the original program is destroyed. Furthermore, static analysis of the obfuscated program reveals only the structure of the virtual machine, and dynamic analysis produces a dynamic trace where original program instructions are intermixed, and often indistinguishable from, virtual machine instructions. We present a dynamic analysis approach whereby all instructions that affect the external behavior of the program are identified, thus building an approximation of the original program that is observationally equivalent. We achieve good results at both identifying instructions from the original program, as well as eliminating instructions known to be part of the virtual machine.