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Ligi, R., A. Vigan, R. Gratton, Boer J. de, M. Benisty, A. Boccaletti, S. P. Quanz, et al. "Investigation of the inner structures around HD 169142 with VLT/SPHERE." OXFORD UNIV PRESS, 2018. http://hdl.handle.net/10150/627059.
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We present observations of the Herbig Ae star HD 169142 with the VLT/SPHERE instruments InfraRed Dual-band Imager and Spectrograph (IRDIS) (K1K2 and H2H3 bands) and the Integral Field Spectrograph (IFS) (Y, J and H bands). We detect several bright blobs at similar to 180 mas separation from the star, and a faint arc-like structure in the IFS data. Our reference differential imaging (RDI) data analysis also finds a bright ring at the same separation. We show, using a simulation based on polarized light data, that these blobs are actually part of the ring at 180 mas. These results demonstrate that the earlier detections of blobs in the H and K-S bands at these separations in Biller et al. as potential planet/substellar companions are actually tracing a bright ring with a Keplerian motion. Moreover, we detect in the images an additional bright structure at similar to 93 mas separation and position angle of 355 degrees, at a location very close to previous detections. It appears point-like in the YJ and K bands but is more extended in the H band. We also marginally detect an inner ring in the RDI data at similar to 100 mas. Follow-up observations are necessary to confirm the detection and the nature of this source and structure.
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Waszek, Lauren Esme. "A body wave study of the seismic velocity and attenuation structures of Earth's inner core." Thesis, University of Cambridge, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.610770.
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Kotera, Yuriko. "Three-Dimensional Imaging of Macular Inner Structures in Glaucoma by Using Spectral-Domain Optical Coherence Tomography." Kyoto University, 2011. http://hdl.handle.net/2433/142538.
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Таран, Л. А., Світлана Олексіївна Швачко, Светлана Алексеевна Швачко, and Svitlana Oleksiivna Shvachko. "Проблема определения пословиц." Thesis, Астана: Изд-во ЕНУ им. Л.Н. Гумилева, 2016. http://essuir.sumdu.edu.ua/handle/123456789/44658.
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Пословицы и поговорки, или как их еще называют – паремии, относятся к нетипичным текстам, которые отличаются отсутствием сильных позиций, фабулы, структурно-композиционных параметров обычных текстов, зафиксированного авторства и адресата.Досліджується питання фразеологізації нумеральних словосполучень, їх лексикалізації в англомовному та україномовному дискурсах, вивчається процес поліфункціональності.
Исследуются вопросы фразеологического бытия, лексикализации словосочетаний на материале англоязычного и украиноязычного дискурсов, интерлингвальная корреляция изучается в русле полифункциональности.
The paper in question deals with phraseological units in the English and Ukrainian discourses. The process of lexicalization is being dealt with the phraseological state in terms of polyfunctionality and epidigmatic function into that.
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Danilo, Laure. "Evolution des structures neurocrâniennes des Equoidea (Mammalia, Perissodactyla) européens paléogènes." Thesis, Montpellier 2, 2012. http://www.theses.fr/2012MON20190/document.
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La radiation adaptative des Equoidea est encore mal comprise en raison notamment de la méconnaissance de la phylogénie de cette super-famille. La principale irrésolution de ces relations de parenté porte sur les pachynolophes, Equoidea européens rapprochés des Equidae ou des Palaeotheriidae. Pendant une grande part de l'Éocène, l'Europe est isolée et subit à la fin de cette période de profonds changements climatiques. Lors de la Grande Coupure son isolement s'achève, tandis que l'aridité du climat s'installe, et des faunes migrantes provoquent l'extinction de nombreux groupes endémiques. Un Equoidea européen basal, richement représenté par un matériel bien préservé permet d'appuyer une des hypothèses phylogénétiques les plus récentes. Cependant, les caractères couramment utilisés pour débattre de cette question n'apportent pas de réponse claire et définitive. Aussi, cette étude se propose de mener des investigations sur des régions encore peu explorées de ces animaux comme le neurocrâne, grâce à la microtomographie (CT scan), qui permet un accès non destructif aux structures (encéphale, pétreux, labyrinthe osseux, sinus). Outre l'intérêt phylogénétique, ces organes peuvent, de par leurs fonctions, receler un intérêt paléoécologique. Jusqu'à présent, peu d'études à large échelle ont porté sur ces structures chez les Perissodactyla, s'agissant pour la plupart de mentions anecdotiques. Comme préalable indispensable, une étude modèle a été réalisée sur un Equidae sauvage actuel afin de mieux appréhender la variabilité de ces structures méconnues. Pour la première fois, un large échantillon d'Equoidea européens a été scanné et leurs structures neurocrâniennes reconstruites en trois dimensions virtuelles. Ce sont au total 20 espèces qui ont été échantillonnées, couvrant l'évolution de ces animaux de leur origine à leur extinction, pendant plus de 20 millions d'années. Leurs crânes ont été scannés, leurs structures internes reconstruites, comparées et analysées au moyen de la cladistique. Une nouvelle hypothèse phylogénétique propose des relations de parenté intra-Equoidea et montre la pertinence des caractères neurocrâniens, tout en conduisant à envisager une étude plus vaste. Les Palaeotheriidae apparaissent comme un groupe très diversifié, notamment au regard des Equidae éocènes d'Amérique du Nord, et caractérisé par une évolution en mosaïque. Ils connaissent une évolution cérébrale précoce par rapport aux faunes contemporaines (Equidae, Cetartiodactyla, Carnivora), ce qui, via le développement de nouvelles stratégies adaptatives, pourrait expliquer partiellement cette grande diversification familiale. Un parallèle est envisagé avec l'évolution endémique des Notoungulata, qui semblent eux aussi montrer une complexification cérébrale précoce. Cependant, face à un environnement biotique et abiotique bouleversé (fin de l'Éocène et lors de la Grande Coupure), ces structures complexes impliquant un coût métabolique important et une trop grande spécialisation, avec en conséquence, moins de potentiel adaptatif, auraient pu les désavantager et les conduire à l'extinctionThe Equoidea adaptive radiation still remains badly known, especially due to the ignorance of their phylogeny. The main indecision of these relationships concerns the pachynolophs, European Equoidea either approached to the Equidae or to the Palaeotheriidae. During a great part of the Eocene times, Europe was isolated, and, at the end of this period, has undergone strong climatic changes. That isolation ended at the « Grande Coupure » event, whereas an arid climate moved, and migrant faunas caused the extinction of many endemic groups. A basal European Equoidea, richly represented by well-preserved material, can support one of the latest phylogenetic hypotheses. However, commonly used characters to discuss this issue do not provide a clear and definitive answer.Therefore, this study aims to investigate on unexplored regions of these animals as the neurocranium through microtomography (CT), which allows access to non-destructive structures (brain, petrosal, bony labyrinth, and sinus).Furthermore phylogenetic interest these bodies may, through their functions, harbor paleoecological interest. Until now, few large-scale studies have focused on those structures in the Perissodactyla, with regard to most were anecdotal reports. As a prerequisite, a model study was performed on a wild current Equidae to better understand the variability of these unknown structures. For the first time, a large sample of European Equoidea has been scanned and their neurocranium structures virtually reconstructed in three-dimensions. A total of 20 species were sampled, covering the evolution of these animals from their origin to their extinction, for over 20 million years. Their skulls were scanned; their internal structures reconstructed compared and analyzed using cladistics. A new phylogenetic hypothesis provides intra Equoidea relationships and shows the relevance of neurocranium characters, while driving to consider a larger study. The Palaeotheriidae appears as a highly diverse group, particularly with regard to Eocene Equidae in North America, and characterized by a mosaic evolution. Their brain evolved earlier than that of contemporary faunas (Equidae, Cetartiodactyla, Carnivora); which may partially explain the strong diversification of that family, through the development of new adaptive strategies
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Ben, Kahla Haithem. "Sur des méthodes préservant les structures d'une classe de matrices structurées." Thesis, Littoral, 2017. http://www.theses.fr/2017DUNK0463/document.
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Les méthodes d'algèbres linéaire classiques, pour le calcul de valeurs et vecteurs propres d'une matrice, ou des approximations de rangs inférieurs (low-rank approximations) d'une solution, etc..., ne tiennent pas compte des structures de matrices. Ces dernières sont généralement détruites durant le procédé du calcul. Des méthodes alternatives préservant ces structures font l'objet d'un intérêt important par la communauté. Cette thèse constitue une contribution dans ce domaine. La décomposition SR peut être calculé via l'algorithme de Gram-Schmidt symplectique. Comme dans le cas classique, une perte d'orthogonalité peut se produire. Pour y remédier, nous avons proposé deux algorithmes RSGSi et RMSGSi qui consistent à ré-orthogonaliser deux fois les vecteurs à calculer. La perte de la J-orthogonalité s'est améliorée de manière très significative. L'étude directe de la propagation des erreurs d'arrondis dans les algorithmes de Gram-Schmidt symplectique est très difficile à effectuer. Nous avons réussi à contourner cette difficulté et donner des majorations pour la perte de la J-orthogonalité et de l'erreur de factorisation. Une autre façon de calculer la décomposition SR est basée sur les transformations de Householder symplectique. Un choix optimal a abouti à l'algorithme SROSH. Cependant, ce dernier peut être sujet à une instabilité numérique. Nous avons proposé une version modifiée nouvelle SRMSH, qui a l'avantage d'être aussi stable que possible. Une étude approfondie a été faite, présentant les différentes versions : SRMSH et SRMSH2. Dans le but de construire un algorithme SR, d'une complexité d'ordre O(n³) où 2n est la taille de la matrice, une réduction (appropriée) de la matrice à une forme condensée (J(Hessenberg forme) via des similarités adéquates, est cruciale. Cette réduction peut être effectuée via l'algorithme JHESS. Nous avons montré qu'il est possible de réduire une matrice sous la forme J-Hessenberg, en se basant exclusivement sur les transformations de Householder symplectiques. Le nouvel algorithme, appelé JHSJ, est basé sur une adaptation de l'algorithme SRSH. Nous avons réussi à proposer deux nouvelles variantes, aussi stables que possible : JHMSH et JHMSH2. Nous avons constaté que ces algorithmes se comportent d'une manière similaire à l'algorithme JHESS. Une caractéristique importante de tous ces algorithmes est qu'ils peuvent rencontrer un breakdown fatal ou un "near breakdown" rendant impossible la suite des calculs, ou débouchant sur une instabilité numérique, privant le résultat final de toute signification. Ce phénomène n'a pas d'équivalent dans le cas Euclidien. Nous avons réussi à élaborer une stratégie très efficace pour "guérir" le breakdown fatal et traîter le near breakdown. Les nouveaux algorithmes intégrant cette stratégie sont désignés par MJHESS, MJHSH, JHM²SH et JHM²SH2. Ces stratégies ont été ensuite intégrées dans la version implicite de l'algorithme SR lui permettant de surmonter les difficultés rencontrées lors du fatal breakdown ou du near breakdown. Rappelons que, sans ces stratégies, l'algorithme SR s'arrête. Finalement, et dans un autre cadre de matrices structurées, nous avons présenté un algorithme robuste via FFT et la matrice de Hankel, basé sur le calcul approché de plus grand diviseur commun (PGCD) de deux polynômes, pour résoudre le problème de la déconvolution d'images. Plus précisément, nous avons conçu un algorithme pour le calcul du PGCD de deux polynômes bivariés. La nouvelle approche est basée sur un algorithme rapide, de complexité quadratique O(n²), pour le calcul du PGCD des polynômes unidimensionnels. La complexité de notre algorithme est O(n²log(n)) où la taille des images floues est n x n. Les résultats expérimentaux avec des images synthétiquement floues illustrent l'efficacité de notre approcheThe classical linear algebra methods, for calculating eigenvalues and eigenvectors of a matrix, or lower-rank approximations of a solution, etc....do not consider the structures of matrices. Such structures are usually destroyed in the numerical process. Alternative structure-preserving methods are the subject of an important interest mattering to the community. This thesis establishes a contribution in this field. The SR decomposition is usually implemented via the symplectic Gram-Schmidt algorithm. As in the classical case, a loss of orthogonality can occur. To remedy this, we have proposed two algorithms RSGSi and RMSGSi, where the reorthogonalization of a current set of vectors against the previously computed set is performed twice. The loss of J-orthogonality has significantly improved. A direct rounding error analysis of symplectic Gram-Schmidt algorithm is very hard to accomplish. We managed to get around this difficulty and give the error bounds on the loss of the J-orthogonality and on the factorization. Another way to implement the SR decomposition is based on symplectic Householder transformations. An optimal choice of free parameters provided an optimal version of the algorithm SROSH. However, the latter may be subject to numerical instability. We have proposed a new modified version SRMSH, which has the advantage of being numerically more stable. By a detailes study, we are led to two new variants numerically more stables : SRMSH and SRMSH2. In order to build a SR algorithm of complexity O(n³), where 2n is the size of the matrix, a reduction to the condensed matrix form (upper J-Hessenberg form) via adequate similarities is crucial. This reduction may be handled via the algorithm JHESS. We have shown that it is possible to perform a reduction of a general matrix, to an upper J-Hessenberg form, based only on the use of symplectic Householder transformations. The new algorithm, which will be called JHSH algorithm, is based on an adaptation of SRSH algorithm. We are led to two news variants algorithms JHMSH and JHMSH2 which are significantly more stable numerically. We found that these algortihms behave quite similarly to JHESS algorithm. The main drawback of all these algorithms (JHESS, JHMSH, JHMSH2) is that they may encounter fatal breakdowns or may suffer from a severe form of near-breakdowns, causing a brutal stop of the computations, the algorithm breaks down, or leading to a serious numerical instability. This phenomenon has no equivalent in the Euclidean case. We sketch out a very efficient strategy for curing fatal breakdowns and treating near breakdowns. Thus, the new algorithms incorporating this modification will be referred to as MJHESS, MJHSH, JHM²SH and JHM²SH2. These strategies were then incorporated into the implicit version of the SR algorithm to overcome the difficulties encountered by the fatal breakdown or near-breakdown. We recall that without these strategies, the SR algorithms breaks. Finally ans in another framework of structured matrices, we presented a robust algorithm via FFT and a Hankel matrix, based on computing approximate greatest common divisors (GCD) of polynomials, for solving the problem pf blind image deconvolution. Specifically, we designe a specialized algorithm for computing the GCD of bivariate polynomials. The new algorithm is based on the fast GCD algorithm for univariate polynomials , of quadratic complexity O(n²) flops. The complexitiy of our algorithm is O(n²log(n)) where the size of blurred images is n x n. The experimental results with synthetically burred images are included to illustrate the effectiveness of our approach
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Aning, Akwasi acheampong. "Bosumtwi impact crater : use of electrical resistivity tomography (ERT) to map the geometry of the inner wall of the crater and the impact related structures." Phd thesis, Université Paris Sud - Paris XI, 2012. http://tel.archives-ouvertes.fr/tel-00849778.
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Des mesures de résistivité électrique et des campagnes d'observations géologiques ont été menées pour cartographier le contact sédiment/roche basale ainsi que les structures d'impact associées au cratère d'impact Bosumtwi datant de 1,07 millions d'années. Le cratère de 10,5 km de diamètre s'est formé dans des roches métamorphiques du Précambrien (2,1 à 2,2 milliard d'années), d'origine sédimentaire et volcanique. Il est actuellement rempli par le lac Bosumtwi de 8,5 km de diamètre. Ce cratère est la source des tektites et microtektites dispersées jusqu'en Côte d'Ivoire et au large des côtes ouest africaine. La campagne de mesures éophysiques consiste en 16 tomographies de résistivité électrique effectuées radialement des rives du lac vers les bords du cratère d'impact. Chaque profil utilise un système d'acquisition multi - électrodes avec une distance minimum entre les électrodes de 5 m. Les données ont été corrigées des effets topographiques et inversées en utilisant le programme commercial d'inversion Res2DInv, avec la norme L1 considérée plus robuste. La zone comprise entre les rives du lac et le bord externe du cratère de divise en trois formations géologiques principales. Les régions de faibles résistivités (< 64 .m) représentent les sédiments de lac. Les zones de resistivités moyennes (entre 128 et 200 .m) sont interprétées comme des brèches liées à l'impact, en dikes, allochtones ou parautochtones. Les régions de hautes résistivités (> 128 .m) représentent les roches métamorphiques sous-jacentes, d'origine volcanique ou sédimentaire. Les profils de résistivités permettent de retrouver la géométrie et l'extension latérale de ces trois types de roches. Une correspondance directe entre la lithologie observée en surface et les structures mises en évidence par les mesures de résistivité électrique dans le sous-sol est observée à Dwamam au Sud-Est dulac. À Dwamam, les sédiments sont environ à 200 m de la rive du lac et s'étendent environ sur 400 m vers les les bords du cratère, à la différence des autres zones où ont pu être cartographiés les sédiments. La topographie du contact sédiment/roche basale présente une direction particulière NE-SO avec un pendage variant entre 16 degrés au NE et 36 degrés au SO. Une majorité de fractures ont été remarquées dans le SO, remplies par des clasts et des brèches d'impacts. Les failles sont surtout présentent à l'Ouest du lac. En moyenne elles présentent un pendage variant entre 60o à l'Est et 80 degrés à l'Ouest du cratère. Des analyses statistiques ont été effectuées sur les directions et les pendages des failles selon les loi de von Mises et Fisher. Elles démontrent que les failles s'alignent préférentiellement le long de deux directions principales. L'analyse cumulée de la surface de contact sédiment/roche, des failles et de la localisation du champ de dispersion des tektites indique que le bolide d'environ 0,8 à 1 km de diamètre responsable du cratère est arrivé du NE. Les résultats démontrent que les panneaux de résistivité électrique fournissent des informations utiles pour l'étude des cratères d'impact.
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Fossat, Pascal. "Homogénéisation périodique de plaques raidies à résonance interne." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSET014/document.
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Ce travail est consacré à la description macroscopique de deux types de plaques structurées contrastées dont le comportement dynamique est atypique : le premier cas correspond à une plaque raidie dans une direction par des raidisseurs régulièrement espacés, le second correspond au cas d’une plaque bi-raidie dans les deux directions par un treillis périodique de poutres. Les différents régimes de comportement sont spécifiés en fonction des paramètres mécaniques et géométriques des raidisseurs et de la plaque. Le comportement dynamique de ces plaques est établi en faisant émerger, par homogénéisation asymptotique, la description locale et globale. Le modèle est construit à partir des équations élasto-dynamiques tri-dimensionnelles du matériau combinées à des développements asymptotiques. Le travail se concentre sur des situations de résonance interne qui correspondent à des contrastes spécifiques entre les paramètres de la plaque et du raidisseur. L’analyse met clairement en évidence les cinématiques enrichies de la plaque et aboutit à un modèle analytique macroscopique qui inclut les mécanismes de torsion et de flexion. Dans le cas de la plaque mono-raidie, un modèle hybride fait intervenir des paramètres effectifs dont les expressions analytiques sont précisées. Ce modèle est analogue à un modèle de poutre et permet d’appréhender le comportement de la plaque en incluant la résonance interne. Ce modèle non conventionnel montre la coexistence de deux régimes dynamiques. Les caractéristiques de dispersion atypique associées aux ondes de flexion et de torsion proviennent de paramètres effectifs dépendants de la fréquence, comme la masse effective, l’inertie de rotation effective, et la rigidité de torsion effective associées à la plaque. Cette théorie est ensuite étendue au cas de la plaque bi-raidie, et conduit à un opérateur de type plaque non conventionnel incluant des paramètres effectifs. Ces résultats permettent d’examiner des courbes de dispersion atypiques en fonction des contrastes géométriques et mécaniques entre les différents composants. La validité des modèles et leur robustesse sont vérifiées en comparant les résultats analytiques à des simulations numériques de type éléments finis WFEM. Les comparaisons montrent que les mécanismes observables numériquement sont bien décrits par le modèle analytique proposé. Enfin, deux maquettes sont utilisées pour la validation expérimentale : une correspondant à une plaque mono-raidie comportant un contraste géométrique, et l’autre correspondant à la plaque bi-raidie impliquant des contrastes géométrique et mécanique. Les réponses mesurées par vibromètre laser sont traitées par corrélation d’onde IWC. Les mesures sont reproduites pour plusieurs conditions limites de plaques internes et différentes valeurs de masse ajoutées pour montrer la performance du modèle homogénéisé. Une très bonne corrélation apparaît entre les mesures expérimentales et les prédictions issues du modèle. Cette approche peut être utilisée pour décrire le comportement de panneaux raidis industriels et pour concevoir des structures ayant des propriétés spécifiques à certaines fréquencesThis work is devoted to the modeling of two types of contrasted structured plates that exhibit non-conventional dynamic behavior : the first one corresponds to periodic unidirectionally stiffened plates and the second one corresponds to orthogonally stiffened plates. The different regimes of behavior are specified, according to the mechanical and geometrical parameters of the beam and the plate. The dynamic behavior of such stiffened plates is established by up-scaling, through multi-scale asymptotic method, the linear local description of the plate and the stiffening beams coupled together. The behavior is derived from the three-dimensional elastodynamic laws of the materials combined with asymptotic expansions formulation. The study focuses on situations of inner resonance that corresponds to specific mechanical contrasts between the beam and plate parameters. The analysis clearly evidences the enriched kinematics of such plate and yields to a synthetic and analytic macroscopic representation that encompasses the flexural and torsional mechanisms, as well as guided waves. In the case of unidirectionally ribbed plates, an effective hybrid beam/plate model is obtained and the analytical expressions of effective parameters are specified. It results in a beam-like operator that provides a simple understanding of the behavior taking into account inner resonance. This atypical model accounts from the coexistence of two types of dynamic regimes. The unusual dispersion features of flexural and torsional waves arise from frequency dependent parameters, namely, the effective mass, the effective rotational inertia and the effective torsional spring rigidity associated with the plate. The theory is then extended to an orthogonally ribbed plate, and yields a non-conventional plate model with frequency dependent parameters. These results allow investigating the atypical dispersion equation with respect to the geometrical and mechanical contrasts of the structural components. The validity and robustness of the model are also verified by comparing theoretical predictions with finite element based computations, namely the WFEM (Wave Finite Element Method). Comparisons show that mechanisms identified numerically are correctly predicted by the proposed homogenized model. Finally, two mock-ups are considered experimentally, corresponding to uni-directionally ribbed plate with geometrical contrast and orthogonally ribbed plates involving geometrical and mechanical contrasts. The out-of-plane displacement field under random excitation is measured using a scanning laser vibrometer, then post-processed using the IWC (Inhomogeneous Wave Correlation) method. This is performed for various internal boundary conditions and added mass to highlight the ability of the homogenized model to describe different configurations. A good agreement is found between the experimental measurements and the analytical predictions. The presented approach can be used to describe the motion of ribbed panels of industrial interest and/or to design structures having specific atypical features in a given frequency range
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Loison, Pauline. "Etude de la spore de Bacillus subtilis : caractérisation des structures impliquées dans sa résistance." Thesis, Dijon, 2013. http://www.theses.fr/2013DIJOS078/document.
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La spore bactérienne est une forme microbienne multicouche extrêmement résistante aux perturbations environnementales. Cette résistance est notamment liée à sa structure unique qui est particulièrement peu perméable et compacte. Ce travail de thèse a pour but d’identifier et de caractériser les structures sporales impliquées dans ces propriétés. Des méthodes d’investigations globales comme la RMN ou l’anisotropie de fluorescence ont permis de montrer que le cortex des spores de Bacillus subtilis est modifié par la température, pour des valeurs proches de celle de l’activation de la germination. Ceci aura pour conséquence de modifier l’accès à la membrane interne. Un outil d’étude à l’échelle de la spore, l’imagerie en temps de vie de fluorescence (FLIM) couplé à l’utilisation d’un rotor moléculaire, a également été mis au point. Cet outil a permis de mettre en évidence que la membrane interne de B. subtilis possède une très forte viscosité, environ deux fois plus importante que celle de la membrane d’une cellule végétative. Cette viscosité n’est modifiée par la température qu’au-delà de 65 °C, correspondant également à l’activation de la germination. Une perturbation connue pour modifier l’intégrité de la structure de la spore a également été étudiée : l’éthanol couplé à une température importante (65 ou 70°C). Ce traitement est responsable d’une perméabilisation et d’une inactivation des spores. L’éthanol conduit notamment à l’altération de la membrane interne, dont la viscosité et la perméabilité sont modifiées. Ces résultats apportent de nouvelles données pour la compréhension des mécanismes responsables de l’inactivation des spores. Ils permettent d’envisager des applications, pour lesquelles une maitrise des modifications structurales est nécessaire, comme la microencapsulationThe bacterial spore is a multilayer microbial form which is extremely resistant to environmental perturbations. This resistance is especially due to its unique structure which is particularly compact and weakly permeable. This work aims to identify and characterize the spore structures involved in these properties. Overall investigation methods, such as NMR and fluorescence anisotropy, have shown that the cortex of Bacillus subtilis spores is modified by temperature for level similar to that of the activation of germination. This will result in changes to the access to the inner membrane. A tool at the spore’s scale, the fluorescence lifetime imaging microscopy (FLIM) in conjunction with the use of a molecular rotor, has been set up. This tool allowed demonstrating that inner membrane of B. subtilis has a very high viscosity, about two times greater than that of the membrane of a vegetative cell. This viscosity is changed by temperature near 65 °C, which corresponds to activation of germination. A stress known to modify the structural integrity of the spore has also been studied: ethanol combined with significant temperature (65 ou 70 °C). This treatment is responsible for inactivation of spores in parallel with their permeabilization. Ethanol especially leads to alteration of the inner membrane for which the viscosity and permeability are changed. These results provide new understanding of mechanisms implicated in spores’ destruction. They allow considering some new applications, for which it is necessary to control structural changing, for example microencapsulation
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Beaudet, Amélie. "Caractérisation des structures crânio-dentaires internes des cercopithécoïdes et étude diachronique de leurs variations morphologiques dans la séquence Plio-Pléistocène sud-africaine." Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30297/document.
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Les cadres temporel, géographique et environnemental associés à l'émergence et l'évolution des premiers homininés en Afrique du Sud pendant le Plio-Pléistocène constituent des éléments clés dans la compréhension de l'histoire de la lignée humaine. Les cercopithécoïdes, relativement abondants dans les dépôts fossilifères du Néogène africain et quasi systématiquement associés aux restes d'homininés, représentent des marqueurs biochronologiques et des indicateurs écologiques sensibles. Toutefois, en se basant seulement sur les critères morphologiques traditionnels, la systématique du registre cercopithécoïde fossile reste encore incertaine. Afin de mieux caractériser leur paléobiodiversité, nous avons détaillé par des techniques d'imagerie à haute résolution les restes crânio-dentaires de 91 spécimens cercopithécoïdes provenant des sites de Makapansgat, Taung, Sterkfontein, Kromdraai et Swartkrans. En particulier, nous avons mesuré et comparé les variations dans l'organisation endostructurale dentaire, la conformation du labyrinthe osseux et l'architecture endocrânienne à travers l'application de méthodes statistiques et de modélisation virtuelle (e.g., morphométrie géométrique, modèles déformables). À titre comparatif, nous avons également intégré dans nos analyses un échantillon de 80 spécimens cercopithécoïdes actuels. En plus de l'identification de caractères nouveaux et pertinents pour la diagnose des taxons fossiles, nos résultats mettent en évidence des biomarqueurs utiles pour la reconstruction des contextes paléoenvironnementaux et biochronologiques, notamment en ce qui concerne la morphologie de la jonction émail-dentine et l'architecture néocorticale. L'estimation de la paléobiodiversité révèle un certain degré d'homogénéité morphologique pour quelques taxons papionines qui plaide en faveur d'une réduction du nombre d'espèces effectivement présentes dans les gisements fossilifères sud-africainsThe temporal, geographical and environmental frameworks of the early hominin emergence and evolution in South Africa during the Plio-Pleistocene are key elements for the understanding of the human lineage history. The cercopithecoids, relatively abundant in the African Neogene fossiliferous deposits and almost invariably associated with hominin remains, represent sensitive biochronological markers and ecological indicators. However, based on traditional morphological criteria only, the systematics of the cercopithecoid fossil record remains uncertain. In order to better characterize their paleobiodiversity, by means of high-resolution imaging techniques we have detailed 91 South African cercopithecoid craniodental specimens from the sites of Makapansgat, Taung, Sterkfontein, Kromdraai and Swartkrans. More specifically, we measured and compared the variation in dental endostructural organization, bony labyrinth conformation and endocranial architecture through the application of statistical and virtual modeling methods (e.g., geometric morphometrics, deformation-based models). For comparative purposes, we also integrated in our analyses a sample consisting of 80 extant cercopithecoid specimens. Besides the identification of some new characters suitable for the diagnosis of fossil taxa, our results reveal biomarkers useful for the reconstruction of paleoenvironmental and biochronological contexts, notably based on the enamel-dentine junction morphology and the neocortical architecture. The paleobiodiversity assessment highlights a certain degree of morphological homogeneity for some of the papionin taxa and suggests a reduction of the number of species actually present in the South African fossiliferous deposits
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Power, Christopher Brian James. "The inner structure of ΛCDM halos." Thesis, Durham University, 2003. http://etheses.dur.ac.uk/3702/.
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We have used high resolution N-body simulations to investigate the internal properties of Cold Dark Matter (CDM) halos with virial masses of M(_200) ~ 10(^10) M(_o) at z = 0, comparable to those of dwarf galaxy halos, forming in the ACDM cosmology. In particular, we have focused on providing accurate constraints on the mass distribution in these objects at ~ 1% of the virial radius, r(_200)-. After a brief introduction (chapter 1), the first part of this thesis is concerned with establishing the conditions under which the distribution of mass in simulated CDM halos is unaffected by finite numerical resolution. In chapter 2, we present results from a comprehensive set of simulations of a single galaxy mass halo in which numerical parameters have been varied systematically in order to determine their impact on the spherically averaged mass profile. Based on these results, we have defined a set of convergence criteria that allow us to identify the radial extent over which the spherically averaged circular velocity profile can be considered reliably resolved to better than 10%. In chapter 3, we have examined the abundance of substructure found in three sets of "converged" simulations, and quantified the effect of increasing mass resolution on the number of resolved subhalos of a given mass. The second part of this thesis is concerned with the detailed analysis of the internal structure and kinematics of the simulated dwarf galaxy halos in our sample. In chapter 4, we analyse the structure and kinematics of the dwarfs for possible redshift dependence, and investigate whether these halos could sustain a gaseous disk. In chapter 5, we concentrate on mass dependent trends by performing a detailed comparison with galaxy and cluster mass halos. Finally, chapter 6 provides a summary of the main findings of this work and highlights aspects that may prove rewarding for further study.
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Debras, Florian. "Inner structure and atmospheric dynamics of gaseous giant planets." Thesis, Lyon, 2018. http://www.theses.fr/2018LYSEN085/document.
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Lors de cette thèse, je me suis attaché à améliorer notre connaissance des planètes géantes, depuis notre voisine Jupiter jusqu’aux exoplanètes lointaines : les Jupiter chauds. Grâce aux nouvelles observations gravitationnelles extrêmement fines du satellite Juno, entré en orbite autour de Jupiter en juillet 2016, il est possible d’améliorer significativement les modèles de structure interne de la planète. Cependant, cela ne peut se faire qu’à condition d’avoir une méthode suffisamment précise pour exploiter au maximum les données. J’ai donc étudié la méthode des sphéroides de Maclaurin concentriques et ses limitations. A l’aide des connaissances contemporaines sur les équations d’état, les propriétés diffusives et les transition ou séparation de phase entre l’Hydrogène et l’Hélium, il m’a alors été possible de produire de nouveaux modèles de Jupiter. Arriver à combiner les observations gravitationnelles de Juno et les abondances d’éléments observées par Galiléo n’a pu se faire qu’en décomposant Jupiter en au moins 4 zones, de l’enveloppe externe jusqu’au coeur compact. J’ai montré que la taille de ce coeur compact était dégénérée avec la variation d’entropie à l’intérieur de la planète.La structure interne des Jupiter chauds quant à elle est très dépendante de leur dynamique atmosphérique, qui entraîne une inflation de leur rayon. J’ai étudié les atmosphères de ces planètes à l’aide du modèle de circulation globale de l’Université d’Exeter et d’un code linéaire que j’ai développé, appelé ECLIPS3D. La caractéristique la plus importante de la circulation atmosphérique est la présence d’un jet superrotatif, étendu en latitude.J’ai donc étudié la création de ce jet à l’aide d’arguments théoriques pour s’assurer de sa pertinence physique. L’étude de la solution linéaire dépendante du temps, associée à des arguments numériques sur la convergence de quantité de mouvement par les vents verticaux m’ont permis d’établir une compréhension globale, cohérente de l’accélération de la superrotation dans l’atmosphère de ces planètes.Avec ce travail, j’ai amélioré ma compréhension théorique des planètes géantes et développé des codes qui peuvent être utilisés pour améliorer nos connaissances sur la structure interne et la dynamique atmosphérique des planètes géantes, que ce soit Jupiter, Saturne ou les Jupiter chaudsThrough this thesis, I have been motivated by the will to improve our knowledge of giant planets, from our neigh- bouring Jupiter to the far away worlds across the galaxy: hot Jupiters.With the latest, extremely precise observations of the satellite Juno, new models of the interior of Jupiter can be derived. A precise enough method is required to take full advantage of these outstanding data, and I therefore studied the concentric Maclaurin spheroid method and its limitations.With contemporary understanding on the equations of state, diffusive properties and phase transition/separation of hydrogen and helium, I could then focus on producing new interior models of Jupiter. Combining the gravitational observations of Juno with the elemental observations of Galileo has proven to be a complicated task, which required to decompose the planet into at least four regions from the outer envelope to the inner, compact core. I have shown that the size of the compact core is degenerated with the entropy variation within the planet.Concerning hot Jupiters, I have reminded of the need to understand their atmospheric dynamics to constrain their interior structure, as the wind circulation can lead to an inflation of their radius. Studying numerically their at- mospheric dynamics was performed with the University of Exeter’s global circulation model as well as with the development of a linear solver that I called ECLIPS3D. An important, robust feature is the presence of a broad equatorial superrotation in the atmosphere of these planets.Finally, I have explored the spin up of this superrotation on theoretical grounds, to assess its physical relevance. I have calculated the linear time dependent solution to show the importance of differential drag and radiative damp- ing, and have used numerical simulations to highlight the importance of vertical momentum acceleration. Globally, a coherent picture of the initial spin up of superrotation was obtained.Through this work, I have improved my theoretical understanding of giant planets and developed various codes that can be used to study and improve our knowledge of the interior structure and atmospheric dynamics of giant planets, from Jupiter and Saturn to hot Jupiters
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Reaman, Daniel M. "Structure, properties, and dynamic behavior of Earth’s inner core." The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1314319456.
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Petr, Radovan. "Městské divadlo v Kuřimi." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2015. http://www.nusl.cz/ntk/nusl-227681.
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The theme of the master´s theses is to design a wooden structure of city theater with internal steel construction. The concept of wooden structure is developed in two versions according to standard ČSN EN. The theses solve the static effect of the construction and design of individual parts and materials. Theater has dimensions 49.0 x 25.6 m, max. height of 12.5 meters. The construstion is devise to withstand a weight and applicability. The supporting structure of the roof is solved using by 13 arched plate girders. The second variant is designed as arched truss girders. The gable wall is glassed-in, glass envelopes support by wooden structure with columns and side runners. The work also includes solutions for joins and construction details. The structure was solved in the program RSTAB Dlubal 8. The assessment of the components was done using additional module TIMBER Pro. First Variant of plate girder was checking by manual report. The work includes drawings.
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Baumgart, Johannes. "The Hair Bundle: Fluid-Structure Interaction in the Inner Ear." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-63810.
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A multitude of processes cooperate to produce the sensation of sound. The key initial step, the transformation from mechanical motion into an electrical signal, takes place in highly specialized mechanosensitive organelles that are called hair bundles due to their characteristic appearance. Each hair bundle comprises many apposed cylindrical stereocilia that are located in a liquid-filled compartment of the inner ear. The viscous liquid surrounding the hair bundle dissipates energy and dampens oscillations, which poses a fundamental physical challenge to the high sensitivity and sharp frequency selectivity of hearing. To understand the structure-function relationship in this complex system, a realistic physical model of the hair bundle with an appropriate representation of the fluid-structure interactions is needed to identify the relevant physical effects. In this work a novel approach is introduced to analyze the mechanics of the fluid-structure interaction problem in the inner ear. Because the motions during normal mechanotransduction are much smaller than the geometrical scales, a unified linear system of equations describes with sufficient accuracy the behavior of the liquid and solid in terms of a displacement variable. The finite-element method is employed to solve this system of partial differential equations. Based on data from the hair bundle of the bullfrog's sacculus, a detailed model is constructed that resolves simultaneously the interaction with the surrounding liquid as well as the coupling liquid in the narrow gaps between the individual stereocilia. The experimental data are from high-resolution interferometric measurements at physiologically relevant amplitudes in the range from a fraction of a nanometer to several tens of nanometers and over a broad range of frequencies from one millihertz to hundred kilohertz. Different modes of motion are analyzed and their induced viscous drag is calculated. The investigation reveals that grouping stereocilia in a bundle dramatically reduces the total drag as compared to the sum of the drags on individual stereocilia moving in isolation. The stereocilia in a hair bundle are interconnected by oblique tip links that transmit the energy in a sound to the mechanotransduction channels and by horizontal top connectors that provide elastic coupling between adjacent stereocilia. During hair-bundle deflections, the tip links induce additional drag by causing small but very dissipative relative motions between stereocilia; this effect is offset by the horizontal top connectors that restrain such relative movements, assuring that the hair bundle moves as a unit and keeping the total drag low. In the model the stiffness of the links, the stiffness of the stereocilia, and the geometry are carefully adjusted to match experimental observations. The references are stiffness and drag measurements, as well as the coherence measurements for the bundle's opposite edges, both with and without the tip links. The results are further validated by a comparison with the relative motions measured in a sinusoidally stimulated bundle for the distortion frequencies at which movements are induced by the nonlinearity imposed by channel gating. The model of the fluid-structure interactions described here provides insight into the key step in the perception of sound and the method presented provides an efficient and reliable approach to fluid-structure interaction problems at small amplitudesBei der Hörwahrnehmung eines Klangs spielen viele komplexe Prozesse zusammen. Der Schlüsselprozess, die Umwandlung mechanischer Schwingungsbewegung in elektrische Signale, findet in den Haarbündeln im Innenohr statt. Diese Haarbündel sind hoch entwickelte mechanosensitive Organellen, bestehend aus vielen nahe beieinander stehenden Stereozilien umgeben von Flüssigkeit. Die beträchtliche Viskosität dieser Flüssigkeit führt zur Energiedissipation und zur Schwingungsdämpfung, was im Gegensatz zur bekannten hohen Empfindlichkeit und der ausgezeichneten Frequenzselektivität der Hörwahrnehmung steht. Um die Komponenten des Haarbündelsystems in ihrem funktionalen Zusammenspiel besser zu verstehen, bedarf es eines wirklichkeitsgetreuen Modells unter Einbeziehung der Wechselwirkung zwischen Flüssigkeit und Struktur. Mit dieser Arbeit wird ein neuer Ansatz vorgestellt, um die Mechanik der Fluid-Struktur-Wechselwirkung im Innenohr zu analysieren. Da die Bewegungen bei der normalen Mechanotransduktion wesentlich kleiner als die geometrischen Abmessungen sind, ist es möglich, das Verhalten von Fluid und Struktur in Form der Verschiebungsvariable in einem linearen einheitlichen System von Gleichungen ausreichend genau zu beschreiben. Dieses System von partiellen Differentialgleichungen wird mit der Finite-Elemente-Methode gelöst. Basierend auf experimentell ermittelten Daten vom Haarbündel des Ochsenfrosches wird ein detailliertes Modell erstellt, welches sowohl die Interaktion mit der umgebenden Flüssigkeit als auch die koppelnde Flüssigkeit in den engen Spalten zwischen den einzelnen Stereozilien erfasst. Die experimentellen Daten sind Ergebnisse von hochauflösenden interferometrischen Messungen bei physiologisch relevanten Bewegungsamplituden im Bereich von unter einem Nanometer bis zu mehreren Dutzend Nanometern, sowie über einen breiten Frequenzbereich von einem Millihertz bis hundert Kilohertz. Das Modell erlaubt die Berechnung der auftretenden viskosen Widerstände aus der numerischen Analyse der verschiedenen beobachteten Bewegungsmoden. Es kann gezeigt werden, dass durch die Gruppierung zu einem Bündel der Gesamtwiderstand drastisch reduziert ist, im Vergleich zur Summe der Widerstände einzelner Stereozilien, die sich individuell und unabhängig voneinander bewegen. Die einzelnen Stereozilien in einem Haarbündel sind durch elastische Strukturen mechanisch miteinander verbunden: Die Energie des Schalls wird durch schräg angeordnete sogenannte Tiplinks auf die mechanotransduktiven Kanäle übertragen, wohingegen horizontale Querverbindungen die Stereozilien direkt koppeln. Während der Haarbündelauslenkung verursachen die Tiplinks zusätzlichen Widerstand durch stark dissipative Relativbewegungen zwischen den Stereozilien. Die horizontalen Querverbindungen unterdrücken diese Bewegungen und sind dafür verantwortlich, dass sich das Haarbündel als Einheit bewegt und der Gesamtwiderstand gering bleibt. Die Steifigkeit der Stereozilien und der Verbindungselemente sowie deren Geometrie sind in dem Modell sorgfältig angepasst, um eine Übereinstimmung mit den Beobachtungen aus verschiedenen Experimenten zu erzielen. Als Referenz dienen Steifigkeits- und Widerstandsmessungen, sowie Kohärenzmessungen für die gegenüberliegenden Außenkanten des Bündels, die jeweils mit und ohne Tiplinks durchgeführt wurden. Darüberhinaus sind die Ergebnisse durch den Vergleich mit experimentell beobachteten Relativbewegungen validiert, die das Haarbündel infolge von sinusförmiger Anregung bei Distorsionsfrequenzen zeigt. Diese haben ihren Ursprung in dem nichtlinearen Prozess des öffnens von Ionenkanälen. Das entwickelte Modell eines Haarbündels liefert neue Einblicke in den Schlüsselprozess der auditiven Wahrnehmung. Zur Behandlung von Problemen der Fluid-Struktur-Wechselwirkungen bei kleinen Amplituden hat sich der hier ausgearbeitete Ansatz als effizient und zuverlässig erwiesen
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Zelenskaya, Alexandra. "Atomic force microscopic studies of inner ear structure and mechanics /." Stockholm, 2004. http://diss.kib.ki.se/2004/91-7140-021-4/.
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Holmberg, Mika. "On the structure and dynamics of Saturn's inner plasma disk." Licentiate thesis, Uppsala universitet, Institutionen för fysik och astronomi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-218772.
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This licentiate thesis presents our investigation of Saturn's inner plasma disk. The thesis gives an overview of the Cassini-Huygens project, what a plasma is and how we use the Langmuir probe to investigate it, various difficulties related to the measurements, the structure of the magnetosphere of Saturn, with special focus on the inner magnetosphere and the region around the Saturnian moon Enceladus. For our investigation we use the Cassini Langmuir probe to derive ion density and ion velocity in the region from 2.5 to 12 Saturn radii. We show that the dominant part of the plasma torus, ion density above ~15 particle/cm3, is located in between 2.5 and 8 Saturn radii (1 RS = 60,268 km) from the planet, with a north-southward extension of
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Lythgoe, Karen Helen. "Seismic structure of Earth's inner core and its dynamical interpretation." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.708926.
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Dougherty, Richard K. Mir Pablo F. "Organizational structure for inter-agency information operations /." Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA389648.
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Thesis (M.S. in Information Systems and Operations) Naval Postgraduate School, March 2001.Thesis advisors, Carl R. Jones, Thomas, Gerblick. Includes bibliographical references (p. 211-219). Also Available online.
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Huang, Haidong. "Optimal design of a flying-wing aircraft inner wing structure configuration." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7439.
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Flying-wing aircraft are considered to have great advantages and potentials in
aerodynamic performance and weight saving. However, they also have many
challenges in design. One of the biggest challenges is the structural design of
the inner wing (fuselage). Unlike the conventional fuselage of a tube
configuration, the flying-wing aircraft inner wing cross section is limited to a
noncircular shape, which is not structurally efficient to resist the internal
pressure load. In order to solve this problem, a number of configurations have
been proposed by other designers such as Multi Bubble Fuselage (MBF),
Vaulted Ribbed Shell (VLRS), Flat Ribbed Shell (FRS), Vaulted Shell
Honeycomb Core (VLHC), Flat Sandwich Shell Honeycomb Core (FLHC), Y
Braced Box Fuselage and the modified fuselage designed with Y brace
replaced by vaulted shell configurations. However all these configurations still
inevitably have structural weight penalty compared with optimal tube fuselage
layout. This current study intends to focus on finding an optimal configuration
with minimum structural weight penalty for a flying-wing concept in a preliminary
design stage.
A new possible inner wing configuration, in terms of aerodynamic shape and
structural layout, was proposed by the author, and it might be referred as
‘Wave-Section Configuration’. The methodologies of how to obtain a structurally
efficient curvature of the shape, as well as how to conduct the initial sizing were
incorporated.
A theoretical analysis of load transmission indicated that the Wave-Section
Configuration is feasible, and this was further proved as being practical by FE
analysis. Moreover, initial FE analysis and comparison of the Wave-Section
Configuration with two other typical configurations, Multi Bubble Fuselage and
Conventional Wing, suggested that the Wave-Section Configuration is an
optimal design in terms of weight saving. However, due to limitations of the
author’s research area, influences on aerodynamic performances have not yet
been taken into account.
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Xinyu, Chang. "Neuron Segmentation and Inner Structure Analysis of 3D Electron Microscopy Data." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1369834525.
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Patel, Pryank. "Structural studies of the inner DysF domain of human myoferlin." Thesis, Birkbeck (University of London), 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479383.
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Moreira, Bruno D. "The use of multilocus genotypes to infer population structures." Thesis, University of Reading, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553658.
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Being able to determine the kinship structure and the relatedness of individuals are important prerequisite to test many models of evolution, Cepaea nemoralis is an ideal model organism for studying these processes because it has a rich history of research, and with its relatively low dispersal ability lends itself to a high degree of local adaptation over small and relatively easily studied areas. During this project we developed molecular markers to in an attempt to genotype of a population of C. nemoralis in Berrow Somerset. There are several methods available to exploit the discriminative power of DNA markers. These methods can be grouped into two main categories: moment estimators and likelihood estimators (Blouin, 2003; Thomas, 2005; Van-de-Casteele et a/., 2001). The aim of this project is to extend earlier methods of estimating relatedness and to model the probable recent pedigrees of a group of individuals purely from genetic information. This approach aims to model the multi locus genealogy back to a certain point in the past, prior to the point where the ancestral genotypes are drawn from an appropriate frequency distribution, in a similar way to (Gasbarra et al., 2006), taking into account genotypic errors. We developed a Moran model of evolution allowing for overlap of generations and different levels of mating fitness in a Bayesian framework with the use of importance sampling based on an algorithm developed by Beaumont (2003), called group importance metropolis-Hastings algorithm.
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May, James E. "Non-Linear Control of Long, Flexible Structures Employing Inter-Modal Energy Transfer [Modal Damping]." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1247711518.
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Dale, Edward Robert. "Visualizing the inner structure of n-body data using splatting and skeletonization /." Link to online version, 2006. https://ritdml.rit.edu/dspace/handle/1850/2071.
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Boger, Erich Theodore August. "Structure, localization and function of mouse myosin XVa in the inner ear." College Park, Md. : University of Maryland, 2006. http://hdl.handle.net/1903/4312.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2006.Thesis research directed by: Biology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Leung, Wing-kit, and 梁榮傑. "Three dimensional structure and kinematics of the inner ejecta of supernova 1987A." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45542077.
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Holmberg, Mika. "A study of the structure and dynamics of Saturn's inner plasma disk." Doctoral thesis, Uppsala universitet, Institutet för rymdfysik, Uppsalaavdelningen, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-263278.
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This thesis presents a study of the inner plasma disk of Saturn. The results are derived from measurements by the instruments on board the Cassini spacecraft, mainly the Cassini Langmuir probe (LP), which has been in orbit around Saturn since 2004. One of the great discoveries of the Cassini spacecraft is that the Saturnian moon Enceladus, located at 3.95 Saturn radii (1 RS = 60,268 km), constantly expels water vapor and condensed water from ridges and troughs located in its south polar region. Impact ionization and photoionization of the water molecules, and subsequent transport, creates a plasma disk around the orbit of Enceladus. The plasma disk ion components are mainly hydrogen ions H+ and water group ions W+ (O+, OH+, H2O+, and H3O+). The Cassini LP is used to measure the properties of the plasma. A new method to derive ion density and ion velocity from Langmuir probe measurements has been developed. The estimated LP statistics are used to derive the extension of the plasma disk, which show plasma densities above ~20 cm-3 in between 2.7 and 8.8 RS. The densities also show a very variable plasma disk, varying with one order of magnitude at the inner part of the disk. We show that the density variation could partly be explained by a dayside/nightside asymmetry in both equatorial ion densities and azimuthal ion velocities. The asymmetry is suggested to be due to the particle orbits being shifted towards the Sun that in turn would cause the whole plasma disk to be shifted. We also investigate the ion loss processes of the inner plasma disk and conclude that loss by transport dominates loss by recombination in the entire region. However, loss by recombination is still important in the region closest to Enceladus (~±0.5 RS) where it differs with only a factor of two from ion transport loss.
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Granbom, Camilla. "Mounting of Inner Support Structure on the Swedish Warship Vasa : Product Development." Thesis, Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-79005.
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The master’s thesis is focused around the mounting of an inner support structure to the Swedish warship Vasa and was given by Camatec Industriteknik AB. The Swedish warship Vasa is one of the greatest national treasures of Sweden. The ship was built high and narrow, therefore a small gust of wind made her capsize during her maiden journey. Today it is the world’s bestpreserved ship from the 17th century and has been on display for the public at the Vasa museum since the year 1990. The purpose of the master’s thesis was to generate and evaluate concepts for the mounting of the inner support structure to the Swedish warship Vasa. The master’s thesis had the following goals: To generate and analyse possible concepts regarding the mounting. Final proposals of the mounting created in CAD. FEM calculations of the final proposals to ensure that they handle the load conditions properly. The master’s thesis followed the methodical process of product development with the steps: pilot study, concept generation, concept selection and concept evaluation. Three concepts were selected for further analysis. Two concepts involved a timber tong around the hanging knees. One fastened in a present structure of the ship (concept Y2.1) and the other one attached clamping force created by a spring in the construction (concept Y2.2). The third concept was a metal sheet between the main wales at the outside of the ship (concept G5). The concept Y2.1 was eliminated due to high local stress concentrations at the attachment in the ship. The concept Y2.2 showed some desirable features, including visual representation if tension was present. However, it was not ensured that the concept can keep the surface pressure below the maximum 0.15 MPa. Another uncertainty with the concept was the behaviour of the timber tongs if movement of the hull occurred. Therefore, the concept Y2.2 needs additional work before it can be continued or eliminated. The concept G5 handled the loading case without exceeding the required surface pressure. However, a decision whether the metal sheets would be to visible for visitors needs to be taken before continuing with or eliminate the concept. In summary, the concepts need further analysing before a final concept selection can be done.Examensarbetet har fokuserat på infästningen av en inre stödstrukturen till regalskeppet Vasa och har utförts tillsammans med Camatec Industriteknik AB. Vasaskeppet är idag en av Sveriges största nationalskatter. Skeppet byggdes högt och smalt, således fick en mild bris henne att kantra under sin jungfruresa. Det är idag världens mest bevarade skepp från 1600- talet och har funnits på utställning sen 1990. Syftet med examensarbetet var att generera och utvärdera koncept för infästningen av den inre stödstrukturen till regalskeppet Vasa. Målen med examensarbetet var: Att generera och analysera möjliga koncept till infästningen. Modellera de valda koncepten i CAD. Utföra FEM- simuleringar på de valda koncepten för att säkerställa att lasterna fördelas rätt. Examensarbetet följer produktutvecklingsprocessen och har behandlat följande steg: förstudie, konceptgenerering, konceptval samt konceptutvärdering. Tre koncept valdes att tas vidare för djupare analys. Två koncept involverade en timmersax runt knäna på skeppet. Ett som fästes i skeppets befintliga struktur (koncept Y2.1) medans det andra fäste enbart med klämkraft som uppkom tack vare en fjäder i konstruktionen (koncept Y2.2). Det tredje konceptet var en plåt mellan berghultarna på utsidan av skeppet (koncept G5). Konceptet Y2.1 eliminerades på grund av de lokalt höga spänningskoncentrationer som uppkom. Konceptet Y2.2 visade upp önskvärda funktioner, såsom att visuellt påvisa drag. Dock är det inte säkerställt att konceptet genererar ett yttryck under det maximala trycket på 0.15 MPa. Ytterligare är timmersaxens beteende vid rörelse av skrovet osäkert. Således krävs fortsatt arbete med konceptet Y2.2 innan det kan tas vidare eller elimineras. Konceptet G5 hanterade lasterna utan att överskrida den maximala gränsen för yttrycket. Däremot måste ett beslut fattas, angående om plåtarna mellan berghultarna är för synlig eller inte, innan konceptet kan tas vidare eller elimineras. Sammanfattningsvis behöver vidare analys av koncepten ske innan ett slutligt konceptval kan fattas.
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Eizenhöefer, Paul Reinhold. "Subduction and closure of the Palaeo-Asian Ocean along the Solonker suture zone : constraints from an integrated sedimentary provenance analysis." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/211133.
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The Central Asian Orogenic Belt formed by accretion subsequent to the contraction of the Palaeo-Asian Ocean that ultimately disappeared along the Solonker Suture Zone in East Asia. Since typical regional collisional features are absent, the tectonic evolution of the suture remains speculative. Integrated sedimentary provenance analyses across the accretionary collision zone between the Mongolian Arcs and the North China Craton place new constraints on the events that led to final suturing. An investigation on the geochronological and geochemical variability in Permian strata along a southeast-northwest transect revealed distinct differences across the Solonker Suture Zone: northern basins carry a broad Mesoproterozoic to latest Precambrian age signature, and their provenance terranes are of mixed juvenile to crustal magmatic origin. In contrast, southern basins contain detritus from the North China Craton, and their sources are of dominantly crustal contaminated magmatic origin. Provenance analysis suggests, that in the Early Palaeozoic (ca. 429 Ma) the Palaeo-Asian Ocean was consumed along the Uliastai Arc and the North China Craton, initiating the formation of the Northern and Southern Accretionary Orogens, respectively. By the end of the Middle Carboniferous the Mongolian Arcs consolidated after accretion of the Uliastai Arc. In the Late Carboniferous (ca. 314 Ma) the Hegenshan back-arc basin opened, detaching the Northern Accretionary Orogen. While subduction continued there, it may have temporarily ceased along the Southern Accretionary Orogen after accretion of a microcontinent (ca. 300 Ma). During the Middle Permian back-arc basin closure led to the formation and obduction of the Hegenshan supra-subduction zone ophiolite. Eventually, the Palaeo-Asian Ocean closed after wedge-wedge collision, which would not involve continental deep subduction, thus, leading to cryptic suturing from the Late Permian to Early Triassic. Statistical analyses on the heterogeneity and similarity of the age probability density functions require a complex Permian palaeo-geographic setting, involving a variety of arc basins, which received sediments dependent on the contemporary arc geometry. Early stages of the sequence likely resembled a Pacific-type scenario, including Japan-type back-arc basin opening, whereas the late stages were similar to the archipelago-type setting of present-day Southeast Asia.published_or_final_version
Earth Sciences
Doctoral
Doctor of Philosophy
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Wu, Boxian. "An inter-scale correlation structure of peak flow series." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0007/NQ34249.pdf.
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Rico, Jean-Charles. "Structures de la fonction marketing en milieu inter-organisationnel : composantes, déterminants." Poitiers, 1995. http://www.theses.fr/1995POIT4007.
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La fonction marketing des entreprises industrielles (au sens de business to business) est analysee avec un cadre conceptuel emprunte a la theorie des organisations. Apres une phase exploratoire conduite sur 10 entreprises et principalement destinee a operationnaliser les concepts, 60 organisations de divers secteurs d'activite sont etudiees. Les principaux resultats sont presentes, ainsi qu'une analyse typologique sur l'ensemble des variables structurelles du modele. Une phase explicative permet ensuite de mettre en evidence certains facteurs determinant les variables structurelles. Les implications et limites de la recherche sont enfin discuteesThe marketing function in industrial firms (business to business) is analysed through a conceptual frame from organization theory. First, an exploratory phase on ten firms is set up, in order to define relevant indicators for each concept. Then a confirmatory study is launched, on sixty firms from various businesses. Main results are exposed, with a typology on all the structural variables of the model. Then, an explicative phase allows to identify several determining factors of the structural variables. Finally, the limits and implications of the model are discussed
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Karamertzanis, P. G., G. M. Day, G. W. A. Welch, John Kendrick, Frank J. J. Leusen, M. A. Neumann, and S. L. Price. "Modeling the interplay of inter- and intramolecular hydrogen bonding in conformational polymorphs." American Institute of Physics, 2011. http://hdl.handle.net/10454/4734.
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noThe predicted stability differences of the conformational polymorphs of oxalyl dihydrazide and ortho-acetamidobenzamide are unrealistically large when the modeling of intermolecular energies is solely based on the isolated-molecule charge density, neglecting charge density polarization. Ab initio calculated crystal electron densities showed qualitative differences depending on the spatial arrangement of molecules in the lattice with the greatest variations observed for polymorphs that differ in the extent of inter- and intramolecular hydrogen bonding. We show that accounting for induction dramatically alters the calculated stability order of the polymorphs and reduces their predicted stability differences to be in better agreement with experiment. Given the challenges in modeling conformational polymorphs with marked differences in hydrogen bonding geometries, we performed an extensive periodic density functional study with a range of exchange-correlation functionals using both atomic and plane wave basis sets. Although such electronic structure methods model the electrostatic and polarization contributions well, the underestimation of dispersion interactions by current exchange-correlation functionals limits their applicability. The use of an empirical dispersion-corrected density functional method consistently reduces the structural deviations between the experimental and energy minimized crystal structures and achieves plausible stability differences. Thus, we have established which types of models may give worthwhile relative energies for crystal structures and other condensed phases of flexible molecules with intra- and intermolecular hydrogen bonding capabilities, advancing the possibility of simulation studies on polymorphic pharmaceuticals.
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Davoli, Guido. "Galaxy-galaxy strong lensing as a probe of the inner structure of galaxy clusters." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2017. http://amslaurea.unibo.it/13969/.
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La disponibilità di osservazioni profonde di ammassi di galassie, ottenute con telescopi spaziali, ha permesso la scoperta di diversi casi di lensing forte che coinvolgono una galassia d'ammasso e una sorgente retrostante (eventi di galaxy-galaxy strong lensing, GGSL). Ciononostante, questo tipo di eventi sembra essere molto raro nelle più recenti simulazioni idrodinamiche di ammassi di galassie. Questo apparente contrasto fra teoria e osservazioni è uno dei motivi che ci hanno spinto ad indagare sulla fenomenologia degli eventi di GGSL negli ammassi di galassie. Inoltre, lo studio delle sottostrutture presenti negli ammassi è di fondamentale importanza per vincolare le proprietà della materia oscura. In particolare, nella presente tesi abbiamo cercato di verificare la possibile esistenza di un collegamento fra le proprietà fisiche degli ammassi di galassie e la probabilità di osservare eventi di GGSL. Abbiamo quantificato questa probabilità definendo la sezione d'urto per il GGSL. Nel corso del lavoro sono state impiegate simulazioni numeriche di lensing da ammassi di galassie, le cui proprietà rispettano le predizioni del modello cosmologico Lambda-CDM. Nel corso della tesi abbiamo messo in luce come alcune proprietà degli ammassi, quali la pendenza del loro profilo di densità, la funzione di distribuzione radiale e la funzione di massa delle sottostrutture influenzino la sezione d'urto. Questi risultati sono stati confermati quando abbiamo applicato la nostra procedura all'ammasso MACSJ1149. Inoltre, grazie al nostro metodo, abbiamo potuto saggiare la validità di due modelli di massa, ottenuti da un'analisi di lensing forte degli ammassi MACSJ1149 e MACSJ1206, confrontando il numero di eventi di GGSL predetti dai modelli con quelli effettivamente osservati.
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Brattgård, Nils. "Sustainable stormwater management in Stockholm's inner city." Thesis, KTH, Urbana och regionala studier, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298539.
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Much like other cities Stockholm has traditionally used a technical system for managing stormwater. With time this system has become overburdened and has led to large environmental concerns. To reach water quality goals set by the EU Stockholm needs to decrease pollution released to recipients by 70-80%. Green infrastructure (GI) has increasingly been used as an alternative and addition to technical stormwater systems. Many studies have been conducted on different solutions and their stormwater management performance. The City of Stockholm have done research on numerous solutions to evaluate their performance in the context of Stockholm as well. However, implementation in the inner city is slow, thus this study explores why this is the case, and how Stockholm’s stormwater management goals can be reached. Stockholm predominately uses trees planted in plant beds using structural soil, and a combination of constructed wetlands and wet ponds for stormwater management. In new developments there is no real concern, as the GI can be included in planning at an early stage. Including these solutions in existing environments causes issues related to space, both above and below ground, and costs. Therefore, other solutions need to be found. This study explored green roofs, green walls and permeable pavements as possible options. Additionally, it found that finding new space that has previously not been used for GI could be an option. To mitigate financing issues new ways of promoting investment into GI from private property owners could be utilized, but that there also is a mismatch between supposed support for sustainable stormwater management on the political side and funds allocated. Finally, the study recommends that Stockholm takes the technical systems into account and explores what GI measures best work together with it to more effectively decrease pollution.
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Weaver, Yvette Sarah. "A Project Of Discovering The Elements Of Belonging At Mt. Olivet Baptist Church, Columbus, Ohio." Ashland Theological Seminary / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=atssem1618855760437517.
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Varga, Liz. "The Coevolution Of The Firm And The Supply Network: A Complex Systems Perspective." Thesis, Cranfield University, 2009. http://hdl.handle.net/1826/3787.
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A complex adaptive systems approach has been permeating organizational studies and
the field of supply network management helping to describe and explain supply
network dynamics and emergent inter-firm structures. This has improved our
theoretical knowledge of the nature of supply networks transforming raw materials
into products, within a constantly changing environment. From the early days of
simple structures, describing bi-lateral, local arrangements between firms for the
creation of relatively simple products, we are now in an environment of various
supply network archetypes, describing different global sourcing regimes of highly
integrated, sophisticated products within multi-tier networks.
This thesis is a study of the coevolution of the firm and supply network in the
commercial aerospace manufacturing sector producing jetliners of 100 or more seats.
One of the contributions of this research is to demonstrate how the holistic approach
of complexity science can be applied to describe, understand and gain new insight
into the coevolution of the firm and the supply network. Based on the findings of
multiple interviews and questionnaires in eight global aerospace firms across multiple
supply chain tiers, this research finds high-performing clusters of inter-firm
characteristics, plus the aspects of structure and integration which deliver the supply
network performance. Practitioners can use these specific results to examine their
own firms and the new coevolutionary conceptual framework developed in the thesis
may aid future research studies of complex adaptive systems in practice.
The simple survey design and analysis method used in the final research stage of this
research, has the potential for use in other industries, markets and other complex
adaptive systems generally to examine performance outcomes and the effects of
having or adopting new inter-firm characteristics. Finally, implications for policy
include the potential to legitimize supply networks in order to stimulate competition
and innovation in the economy.
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Drachenko, Oleksiy. "Resonance Magnetophonon Inter Sous-Bandes dans les Structures Unipolaires à Cascades Quantiques." Phd thesis, Université Paul Sabatier - Toulouse III, 2004. http://tel.archives-ouvertes.fr/tel-00008037.
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Cette thèse aborde la problématique de la durée de vie des électrons dans des puits quantiques unipolaires soumis à un fort champ magnétique selon l'axe de confinement. Plus particulièrement, le blocage de l'émission de phonons optiques longitudinaux en régime de confinement des électrons à 0-dimension est clairement démontré par la mise en évidence d'oscillations quantiques de la durée de vie. Cet effet est baptisé « résonance magnétophonon inter sous-bandes ». Le blocage de l'émission de phonons LO a été détecté sur la mesure de l'intensité de lasers à cascades quantiques GaAs/GaAlAs, émettant dans le moyen infra rouge autour de 10 µm, soumis à un champ balayé jusqu'à 60T. Le champ magnétique confine les électrons sur des orbites cyclotron, et transforme la dispersion quadratique de l'énergie des sous-bandes en niveaux de Landau discrets. Les oscillations de magnétophonons ont été également trouvées sur la magnétorésistance de la structure. La résonance magnétophonon inter sous-bande réalise une spectroscopie directe des modes de phonons pertinents pour la relaxation inter sous-bande. Entre autres, une contribution des modes de phonon LO de AlAs a été observée tandis que l'intervention attendue de modes confinés n'est pas apparue. La durée de vie inter sous-bandes en fonction du champ magnétique, obtenue par une méthode proposée, est comparée aux prévisions récentes d'un modèle de couplage fort électron-phonon (magnéto polarons). En conclusion, ces travaux ont dégagé des résultats et un nouvel outil performant de spectroscopie de phonons et de diagnostic des interactions électron-phonon dans un système à zéro dimension, analogue à un système de boites quantiques.
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Fuchs, Gunter. "L-Strukturen [Lambda-Strukturen] und S-Strukturen." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2003. http://dx.doi.org/10.18452/14903.
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In dieser Arbeit werden lambda-Strukturen und s-Strukturen eingeführt, und Funktionen S und Lambda entwickelt, die lambda-Strukturen auf s-Strukturen abbilden und umgekehrt. lambda-Strukturen sind eng verwandt mit den in von Jensen untersuchten Prämäusen (iterierbare Prämäuse dieser Art sind lambda-Strukturen), und s-Strukturen wurden in Anlehnung an die von Mitchell und Steel betrachteten Prämäuse definiert. Wieder sind iterierbare Prämäuse dieser Art auch s-Strukturen. Für die Definition dieser Strukturen wurde eine neue, schwache Form der initial segment condition entwickelt (die s'-ISC), die stark genug für die Anwendungen ist. Um zu zeigen, dass die hier entwickelten Funktionen die gewünschte Korrespondenz realisieren, wurden Methoden zur Übersetzung von Formeln entwickelt, die teilweise sehr allgemein gehalten sind. So ist die Übersetzung von Sigma-1-Formeln, die in einer Nachfolgerstufe der Jensen-Hierarchie gelten, in entsprechende Sigma-omega-Formeln in der Vorgängerstufe, anwendbar auf beliebige J-Strukturen. Es werden normale s-Iterationen eingeführt, die den normalen Iterationen von Prämäusen im Sinne von Mitchell-Steel nachgebildet sind, aber auf lambda-Strukturen angewandt werden, und es wird gezeigt, dass die entwickelten Funktionen komponentenweise auf Iterationen angewandt werden können, um normale s-Iterationen von lambda-Strukturen in normale Iterationen von s-Strukturen zu übersetzen, und umgekehrt. Mit diesen Methoden lassen sich auch Iterationsstrategien übersetzen, und man erhält, dass die entwickelten Funktionen normal s-iterierbare lambda-Strukturen auf normal iterierbare s-Strukturen abbilden, und umgekehrt. Auch bleiben die wesentlichen feinstrukturellen Größen, wie bspw. Projekta, und unter gewissen Voraussetzungen (soundness und 1-solidity) auch die Standard-Parameter, erhalten.In this work we introduce lambda-structures and s-structures, and develop functions S and Lambda, which map lambda-structures to s-structures and vice versa. lambda-structures are closely related to the premice studied in recent work of Jensen (iterable premice of this kind are lambda-structures), and s-structures were defined with the premice developed by Mitchell and Steel in mind. Again, iterable premice of this kind are s-structures. For the definition of these structures, a new form of the initial segment condition condition, called s'-ISC, was developed, which is a common weakening of the versions used in by Steel and Jensen. It still suffices for the applications. In order to show that the functions introduced establish the desired correspondence, we developed methods for translating formulae, which in part are very generally applicable. For instance, the translation of Sigma-1-formulae which hold in a successor level of the Jensen-hierarchy into corresponding Sigma-omega-formulae in the predecessor level, can be applied to arbitrary J-structures. We introduce normal s-iterations, which have been designed so as to rebuild the iterations of premice in the sense of Mitchell-Steel but are applied to lambda-structures. It is shown that the translation functions can be applied component-wise to normal iterations, in order to translate normal s-iterations of lambda-structures into normal iterations of s-structures, and vice versa. Using these methods, we can also translate iteration strategies and the result is that the functions introduced in this work map normally s-iterable lambda-structures to normally iterable s-structures, and vice versa. Also,the fundamental fine structural notions, such as projecta, and under additional hypotheses (soundness and 1-solidity) standard-parameters, are preserved.
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Pan, Lei. "The earliest members of the genus Homo in South Africa : evidence from inner structure of lower postcanine dentition." Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30087/document.
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Cette thèse se compose de deux projets individuels et six chapitres, qui sont basées sur l'examen de la structure interne dentaire inférieure dentition postcanine dans un certain nombre de fossiles et modernes spécimens, à travers lesquels une étude approfondie a été effectuée à l'aide de micro-tomodensitométrie et ordinateur-outils de paleonanthropology assistée. Nous avons d'abord recensé et évalué la valeur taxinomique de l'épaisseur de l'émail et des modèles de distribution de l'épaisseur de l'émail 3D entier couronne dans un certain nombre des premiers membres du genre Homo en Afrique du Sud, et examiné dans le relavence taxonomique de EDJ morphologie long postcanine dentition, et discuté de la facteurs d'adaptation possibles / développement qui tiennent compte de la variation de la morphologie EDJ nous avons observé ici. Les trois premiers chapitres (Introduction, Matériel et méthodes) donnent un aperçu des objectifs de cette thèse, et d'examiner les études précédentes. En outre, ils fournissent une introduction détaillée des matières fossiles, les sites et un arrière-plan de la méthode assistée par ordinateur (micro-XCT) pour analyser la structure interne dentaire. Le chapitre des résultats comprend deux documents de recherche indépendants, dans les différentes étapes de soumission et de publication. Les résultats et les chapitres de discussion offrent un résumé détaillé de l'épaisseur de l'émail, EDJ morphométrie géométrique et 3D-EDJ variation métamérique entre les espèces, et de comparer les résultats avec un certain nombre d'études morphologiques et de développement, et de fournir une perspective d'étude future. Le dernier chapitre atteint des points décisifs de cette thèse, il met en évidence la valeur taxinomique des prémolaires EDJ, et met l'accent sur les caractéristiques de la mosaïque de la dentition des premiers membres du genre Homo sud-africaineThis thesis consists of two individual projects and six chapters, which are based on the examination of dental inner structure of lower postcanine dentition in a number of fossil and modern specimens, through which a comprehensive study has been done using micro-computed tomography and computer-assisted paleonanthropology tools. We first documented and assessed the taxonomical value of enamel thickness and 3D whole-crown enamel thickness distribution patterns in a number of earliest members of the genus Homo in South Africa, and looked into the taxonomic relavence of EDJ morphology along postcanine dentition, and discussed the possible adaptive/developmental factors that account for the variation of EDJ morphology we observed here. The first three chapters (Introduction, Materials and Methods) provide an overview of the objectives of this thesis, and review previous studies. Also, they provide a detailed introduction of fossil materials, sites and a background of computer-aided method (micro-XCT) to analyze the dental inner structure. The Results chapter comprises of two independent research papers, in different stages of submission and publication. The Results and Discussion chapters offer an extensive summary of enamel thickness, EDJ geometric morphometrics and 3D-EDJ metameric variation between species, and compare the results with a number of morphological and developmental studies, and provide an outlook of future study. The last chapter reaches the conclusive points of this thesis, it highlights the taxonomical value of premolar EDJ, and emphasizes the mosaic features of the dentition of South African early Homo
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Mannerstedt, Karin. "Synthesis of oligosaccharides from the inner core structure of Haemophilus influenzae and Neisseria meningitidis lipopolysaccharides /." Stockholm : Dept. of organic chemistry, Stockholm university, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-894.
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Vanek, Raymond, and Sophie Walker. "A study of inter-generational activities in structured environments for seniors." CSUSB ScholarWorks, 1996. https://scholarworks.lib.csusb.edu/etd-project/1236.
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This survey research project explored different factors influencing the desire of seniors living in structured residential centers to have inter-generational activities with children from their communities.
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Vandellos, Thomas. "Développement d’une stratégie de modélisation du délaminage dans les structures composites stratifiées." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14380/document.
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Les composites stratifiés de plis unidirectionnels en carbone/époxy sont fortement utilisés pour alléger les structures aéronautiques tout en conservant de bonnes propriétés structurales. Toutefois, les avantages de ce type de matériau ne sont pas encore pleinement exploités de par le manque de confiance accordée aux modèles de prévision de l’endommagement, dont notamment ceux concernant le délaminage. C’est pourquoi l’objectif de cette thèse était de développer une stratégie de modélisation du délaminage adaptée aux structures composites stratifiées. Cette stratégie s’est appuyée sur le développement d’un modèle de zone cohésive prenant en compte les ingrédients nécessaires à la bonne description de l’amorçage et de la propagation de la fissure : (i) un critère d’amorçage avec un renforcement en compression/cisaillement hors-plan, (ii) une loi de propagation décrivant l’évolution de la ténacité en fonction de la mixité de mode et (iii) la prise en compte du couplage inter/intralaminaire. Pour identifier ce nouveau modèle, une procédure d’identification efficace, s’appuyant sur un essai de traction sur plaque rainurée, a été mise en place. Cette procédure d’identification a permis de démontrer que la ténacité semble indépendante (i) de l’orientation des plis adjacents à l’interface et (ii) de l’empilement étudié. De même, pour décrire l’évolution de la ténacité, une nouvelle loi de propagation adaptée au matériau carbone/époxy a été proposée. Pour finir, la stratégie de modélisation, complétée par une stratégie de calcul, a été appliquée sur différents cas structuraux pour mettre en avant ses apports et ses premières limitesThe carbon/epoxy laminated composites of unidirectional plies are strongly used in order to reduce the weight of aeronautical structures while at the same time proposing good structural properties. However, the advantages of this kind of material are not fully exploited due to the lack of confidence in damage models, like ones concerning delamination. Then, the purpose of this work was the development of a strategy to model delamination in laminated composite structures. This strategy was based on the development of a cohesive zone model taking into account the ingredients necessary to the well description of the onset of delamination and the crack growth: (i) an onset criterion with an out-of-plan compression/shearing reinforcement, (ii) a propagation law describing the evolution of the fracture toughness as a function of mixed mode ratio and (iii) the inter/intralaminar coupling. To identify this new model, an efficient identification procedure, basing on a tensile test on notched specimen, has been proposed. This identification procedure has demonstrated that the fracture toughness seems to be independent of (i) the orientation of plies closed to the interface and (ii) the stacking sequence. Furthermore, to describe the evolution of the fracture toughness, a new propagation law adapted to carbon/epoxy material has been proposed. Finally, the strategy to model delamination, completed by a calculation strategy, has been applied on several structural cases to prove its contributions and its first limitations
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Al-Saud, K. F. T. "The inter-penetration of agency and structure within the Saudi bureaucracy." Thesis, Swansea University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635722.
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The place of the public sector bureaucracy in the political, social and economic life of Saudi Arabia is central. It plays a major role in both policy making and implementation and it is charged with development, planning and administration. Therefore whether or not the bureaucracy is succeeding in meeting this responsibility is of interest to and directly affects every member of the society. The purpose of this study is to demonstrate that there are two forces at work within the Saudi bureaucracy. First, there is an overt, formal, systematic and rational structure that has been planned and organised. Secondly, there is a covert, informal, network that has no official status or recognition, yet is immensely powerful. We conceive of the inter-relation of these forces, following its discussion in the literature as 'the dialectic of agency and structure'. This work shows that trying to understand one without the other will deliver at best only a partial understanding. The formal structure follows the overt model of other bureaucracies in the modern world. The second, is based around relationships and personal power differences: between the people who work in the bureaucracy and between those officials and the public. We attempt to show how there is an ever-present interpenetration of agency and structure in Saudi bureaucratic organisational life. By demonstrating that this state of affairs exists, we are not claiming to be able to find a final resolution, much less a solution, to the problems faced by the bureaucracy.
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Westacott, Paul. "Understanding the structure/property/processing inter-relationships in organic semiconducting blends." Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/32261.
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Over the last few years organic semiconductors have seen a dramatic rise in interest from both academia and industry alike. This has been largely due to their promise of low-cost, high-throughput manufacture, combined with many other positive attributes including their: flexibility; semi-transparency and light-weight nature. This combination of factors show that organic semiconductors hold strong potential to compete with inorganic technologies in a number of existing and emerging applications. More specifically, blends comprised of a number organic semiconductors offer significant promise for devices such as organic photovoltaics (OPVs) and organic light emitting diodes (OLEDs), as tuning the chemical nature of the constituting materials can influence the blend’s optoelectronic properties. However, during processing, such as blending, complex mixture of phases are formed which renders understanding these systems challenging. This thesis examines the relationships between the three critical aspects that affect organic semiconducting blends, namely: the processing route selected, the resulting microstructure and, as a consequence, the induced optoelectronic properties. A more comprehensive understanding is developed of how the processing route (solution casting from common solvent vs. bilayer fabrication via lamination) can affect the structural formation processes in organic semiconductor systems, such as crystallisation, vitrification etc. Additionally, this thesis elucidates how the structural formation processes influence the mixture of phases that evolve and discusses how the microstructure that is created affects the photo-physical processes such as exciton quenching and charge generation, within these systems. The results within this thesis highlight the sensitive interplay between the three areas of structure, property and processing. Clear insights into how to manipulate these aspects to positively impact the photo-physical processes are conferred. The findings discussed here give, thus, clear guidelines as to how to further enhance understanding and terminally improve the performance of devices such as organic solar cells.
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McDowell, Melanie A. "Structural studies of the inner membrane ring of the bacterial type III secretion system." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:0c877900-d171-495b-80c1-6a7e5d6c2b21.
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Shigella flexneri attacks cells of the intestinal tract, causing over 1 million deaths annually from bacterial dysentery. A type III secretion system (T3SS) initiates the host-pathogen interaction and transports virulence factors directly into host cells via a needle complex (NC) comprising an extracellular needle and membrane-spanning basal body. Rings formed by the single-pass membrane proteins MxiG and MxiJ are arranged concentrically within the inner membrane ring (IMR) of the NC. The Neterminal domain of MxiG (MxiG-N) is the predominant IMR cytoplasmic structure, however it was structurally and functionally uncharacterised. Determination of the solution structure of MxiG-N in this study revealed it to be a forkhead associated (FHA) domain, although subsequent analyses of conserved residues suggested it does not have the canonical role in cell-signalling via phospho-threonine recognition. Subsequent positioning of the structure in the electron microscopy (EM) density for the S. flexneri NC supported models with 24-fold symmetry in the IMR. Both MxiG and MxiJ also have significant periplasmic domains, which were purified to homogeneity in this study, facilitating preliminary characterisation of their structures and intermolecular interactions. In addition, the entire IMR within the context of intact basal bodies was isolated and visualised in vitro by EM. The essential function of MxiG-N could be to localise the putative cytoplasmic ring (Cering) at the base of the T3SS. Although absolutely required for secretion, the Csring component, Spa33, was structurally uncharacterised. The crystal structure of the Cvterminal domain of Spa33 (Spa33-C) was determined in this study, showing an intertwined dimer that aligned with homologous structures and exhibited a novel interaction with the N-terminus of the ATPase regulator, MxiN. Subsequently, Spa33-C was identified as an altemative translation product of spa33 that formed a 2: 1 complex with Spa33 in vitro. This complex oligomerised further, demonstrating for the first time that Spa33 has the propensity to form the ordered, high molecular weight assemblies that would be required for C-ring formation in S. flexneri.
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Zhang, Hui. "Structural studies of the inner-membrane platform of the bacterial type II secretion system." Thesis, Queen Mary, University of London, 2018. http://qmro.qmul.ac.uk/xmlui/handle/123456789/42808.
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The type II secretion system (T2SS) is widespread in Gram-negative bacteria that cause disease in animals and plants. In human and animal pathogens toxins are secreted (e.g. cholera toxin) and in plant pathogens lytic enzymes that breakdown the plant cell wall are exported in to the extracellular milieu (e.g. pectate lyase). Structurally the T2SS comprises at least 11 core proteins that form three major subassemblies spanning the inner-membrane, periplasmic space and outer-membrane: (i) the inner-membrane platform and associated cytoplasmic ATPase (E); (ii) the pseudopilus, which consists of five pseudopilins, G to K; and (iii) a large, pore-forming outer-membrane complex secretin D. The inner-membrane platform comprises three single transmembrane helix proteins, and one three transmembrane helix protein, OutF. The evidence from cryo-electron microscopy on the related type IVa pilus machine (T4PS) places the protein corresponding to OutF at the centre of this platform. This platform is responsible for assembling the pilus and for communicating between the periplasm and the cytoplasmic ATPase. To date, no high-resolution structure of a full-length OutF/PilC family protein is available. A low-resolution electron microscopy reconstruction of isolated PilG (PilC ortholog from Neisseria meningitides T4PS) showed a tetrameric two lobed structure. Here I report the results of studying the structure of the inner-membrane protein OutF from Dickeya dadantii and the complete inner-membrane platform comprising 9 proteins: OutEFGHIJKLM. This work involved cloning the corresponding operon, purifying the proteins, and using crystallography and electron microscopy. Key results reported here are the crystal structure of the first cytoplasmic domain of Dickeya dadantii, OutF65-172 and a preliminary three-dimensional model of the Dickeya dadantii inner-membrane platform. This model, and higher-resolution models to come, will provide valuable information about the oligomeric state, and arrangement of the inner-membrane proteins. These studies will help us to understand how the type II secretion system works.
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Dunn, A. G. "Bactericidal/permeability-increasing protein, autoimmunity, structural and functional inter-relationships." Thesis, University of Cambridge, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598691.
Full textAbstract:
This thesis describes the investigation into the interactions between anti-neutrophil cyptoplasm antibody (ANCA) autoantibodies to Bactericidal/Permeability Increasing Protein (BPI) and BPI. BPI is located in the azurophilic granules of cells of the myeloid lineage and functions to kill gram negative bacteria, neutralise endotoxin and opsonise bacteria for phagocytosis. Autoantibodies to BPI have been discovered in a range of diseases raising interest in their role in pathogenesis, either through perturbation of BPI's biological function, or through their interaction with BPI expressed on the surface of the primed neutrophils. This thesis describes studies which investigate the epitopes recognised by anti-BPI ANCA, their effect on the functions of BPI in vitro, and their relationship to clinical parameters in a population with the unifying diagnosis of cystic fibrosis. Using molecular fusion proteins of BPI, synthesised by recombinant DNA technology it was found that anti-BPI ANCA recognised epitopes located in the carboxyl domain of BPI, but not the amino terminal. Furthermore they inhibited the BPI mediated opsonisation/phagocytosis of bacteria by neutrophils, a recently characterised function of the carboxyl domain. Anti-BPI autoantibodies, had no effect on the amino terminal functions of BPI. In addition anti-BPI ANCA were found to cause primed neutrophils to undergo respiratory burst. When a cystic fibrosis population was investigated for the prevalence of anti-BPI ANCA it was found that anti-BPI antibody levels showed a strong association with patient bacterial colonisation status. These results suggest that anti-BPI ANCA may contribute to chronic infection and inflammation in diseases such as cystic fibrosis by impairing bacterial phagocytosis and activating neutrophils.
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Boyer, Marissa. "Towards Solving the Structure of Inner Ear and Synaptic Proteins, Cadherin-23 and Calsyntenins 1-3." The Ohio State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1587661520008493.
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Thompson, Buckley Rodger. "Urban [infra]structure : using neglected infrastructure as a framework for the regeneration of inner city voids." Diss., University of Pretoria, 2016. http://hdl.handle.net/2263/53347.
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November of 2014 saw the approval and commission of Tshwane's 2055 vision for the city (Tshwane municipality, 2013: 6). It seeks the restructuring and rejuvenation of the inner city in an attempt to remedy a state of stasis resulting from urban decentralization and fragmentation. Although Tshwane's proposal has potential, its formal exclusive nature and prioritization of the city centre has initiated a process of decay in the informal zones of the urban periphery. This process of decay is particularly evident within the city block of Brown Street. Once a place where many a union march started, Brown Street now exists as a shadow of its former self (Valeska, 2013). A lack of supporting infrastructure and appropriate spatial conditions have facilitated a sharp increase in crime. The consequent privation of safety has, in turn, prompted vacancies of onsite industries. (Valeska, 2013). The loss of formal economic infrastructure (energy) alongside the simultaneous degradation of adjoining infrastructure has inevitably led to the decay of this city block.
This dissertation focuses on the possibility of rehabilitating and regenerating the decaying "in-between" (Woods, 1997: 13) spaces of the city block within its urban periphery. A theoretical approach to transformation is proposed, which, instead of opting for demolition, seeks to expand on existing systems. Therefore, by harnessing site potential, the project suggests that the neglected infrastructure become part of a regenerative machine; a system of components that will stimulate the re-investment and development of the city block. The main intention of the [infra]structure is to establish a coordinated relationship between the formal and informal of the city, the vision and the void. The goal is to create an organized centrality, where fragmented realities are brought together harmoniously using the neglected infrastructures as mediator.Mini Dissertation (MArch(Prof))--University of Pretoria, 2016.
tm2016
Architecture
MArch(Prof)
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