Self and On-selfadjoint Sturm-Liouville Operators with Exponentially Decaying Potentials

In this thesis we investigate the properties of a class of linear differential operators known as Sturm-Liouville operators. Sturm-Liouville operators arise from differential equations of the form - y”+q(x)y = λy, where q is known as the potential and λ is a spectral parameter. This differential equation has been of great importance in mathematics and physics alike. We allow the potential to be real or complex valued and assume that q satisfies |q(x)|≤ce-ax, x≥0, where a \u3e0 and c \u3e 0. We first give a brief account of the mathematical background we will be using and then proceed to give a summary of Sturm-Liouville theory on the half-line, following Weyl, Titchmarsh, Sims and Naimark. In chapter three, we investigate the properties of a series derived initially by Eastham, identify zero-free regions for the Jost solution of the Sturm-Liouville equation and conclude by highlighting the significance of our results in terms of the eigenvalues, resonances and spectral singularities of the Sturm-Liouville operator. We also give several examples to support the validity of our results. The last chapter is dedicated to the study of a series derived by Harris and Gilbert. We show that this series can be used to complement the results obtained in the previous chapter and, finally, we use the property of this series to investigate the points of spectral concentration associated with the Sturm-Liouville operator

Muséologie, patrimoine, humanités numériques et 3D

International audienceLa communication se propose d’approfondir les réflexions menées sur la place et le rôle des publics dans le cadre de recherches interdisciplinaires menées au sein des établissements d’enseignement supérieurs et de recherche de Nantes. A partir de cas d’études patrimoniaux, elle vise à définir une nouvelle approche de la médiation culturelle et patrimoniale et tend à établir les nouvelles bases du processus de création/recréation des espaces et objets patrimoniaux (patrimoine matériel et immatériel) à partir de nou-veaux paradigmes épistémologiques des Humanités Numériques unissant tant les approches en science humaine et sociale qu’en ingénierie 3D

Creating interactivity of our heritage stored in Museums: Experimentation with Château des Ducs de Bretagne History Museum of Nantes, France

International audienceFor the 2006 VRIC conference, we presented a scientific article dealing with a new way of thinking our technical heritage. We propose to preserve it as a digital object. However it does not mean beautiful 3D animation with nice static rendering; indeed, we create virtual mock-up which are dynamically operating. We use CAD software and engineering simulation tools. Nowadays the global methodology has been improved: it is named Advanced Industrial Archaeology. In this communication, we will detail a new experimentation done in partnership with a French museum: the Château des Ducs de Bretagne in France. This project deals with a physical mock-up of Nantes city built in 1899 and exposed in 1900 for the World Fair that took place in Paris, France. The heritage object is nowadays in the museum but exposed as “a fish inside an aquarium”. Thanks to a virtual system coupling a tactile screen with semantic research modules, a 3D active screen and a light pointer, it will allow the visitor to better understand the mock-up and emphasize important places of Nantes city life

Angoulins – ZA des Ormeaux

Le projet d’extension d’un ensemble commercial sur la ZA des Ormeaux, à Angoulins, est à l’origine du diagnostic mené du 30 janvier au 3 février 2017 sur une emprise de 16 173 m2. Il se situe à proximité immédiate du site des Ormeaux, fouillé en 2005 par P. Maguer et qui a fait l’objet de plusieurs publications. La fouille réalisée en 2005 avait permis d’explorer un site littoral de La Tène sur un peu plus de 14 000 m2, sur lequel trois principales phases d’occupation avaient pu être mises en..

Barbezieux – ZA Plaisance

Le projet d’implantation d’une concession de matériel agricole est à l’origine de la présente fouille, réalisée au printemps 2017 sur une partie de la parcelle cadastrée F1034, sur la frange orientale de la ZA de Plaisance. Situé à proximité immédiate du site des Petits Clairons sur lequel plusieurs opérations archéologiques ont été réalisées à partir du début des années 1990 dans le cadre de l’aménagement de la déviation de la RN 10 et des routes permettant de desservir la nouvelle zone arti..

Gomez de Soto J., Kerouanton I., 2009. Les premiers objets en fer en France, à l'âge du Bronze. (actes du XXXe colloque international de l'A.F.E.A.F., Saint-Romain-en-Gal, 26-28 mai 2006)

International audienceInventory of first iron Bronze Age artefacts in France, & iron diffusion road during IX th c. B.C.Inventaire critique des objets en fer de l'âge du Bronze en France. Voies de diffusion du fer au IXe s. av. J.-C

A case study of capitalisation and valorisation of our technical heritage

International audienceFor the 2008 CIRP Design conference, we have presented a scientific article dealing with a new way of thinking our technical heritage: we would like to preserve it as a digital object. Project deals with a physical mock-up of Nantes city built in 1899 and used for the Universal exposition in France in 1900 in Paris. The heritage object is nowadays in the museum but exposed as a fish inside an aquarium. Thanks to a virtual system coupling a tactile screen with semantic research modules, 3D active screen and light pointer, it will allow the visitor to better understand the mock-up and emphasize important places of Nantes city life. However it does not mean beautiful 3D animation with nice static rendering; indeed, we create virtual mockups which are dynamically operating. We use CAD software and engineering simulation tools. Nowadays the global methodology has been improved: it is named Advanced Industrial Archaeology. In this communication, we will detail a new experimentation done in partnership with a French museum: the Château des Ducs de Bretagne in France. This project deals with a physical mock-up of Nantes city built in 1899 and exposed in 1900 for the World Fair that took place in Paris, France. The heritage object is nowadays in the museum but exposed as “a fish inside an aquarium”. Thanks to a virtual system coupling a tactile screen with semantic research modules, a 3D active screen and a light pointer, it will allow the visitor to better understand the mock-up and emphasize important places of the city. The mock-up represents our industrial heritage with old shipyards of Nantes

Récit historique et objet technique : outil de valorisation mutuelle

National audienceDans le domaine de l’histoire des techniques et du patrimoine matériel, l’informatisation est massive, autant sur le plan de l’écriture, que des sources (archives) ou de la valorisation. Cependant les articulations entre ces plans (archive, recherche, valorisation) restent faibles. Ce travail propose un outil numérique de gestion de contenu historique (récits et sources) pour documenter et valoriser les objets du patrimoine technique. En fonction des situations, différentes interfaces permettent d’accéder aux connaissances, une interface de navigation en 3D est ici proposée en exemple. L’objet technique et le travail de l’historien sont conjointement valorisés

Occurrence and genetic diversity of Salmonella in organic and conventional pig productions in France

The objectives of this study were 1) to assess the occurrence of Salmonella in organic pig production, in comparison with conventional pig production, 2) to evaluate the genetic diversity of strains isolated from these two productions and 3) to estimate the cross-contamination on slaughter line between conventional pig and organic pig. In one slaughterhouse, 26 organic herds and 31 conventional herds (2 pigs per herd) were sampled for Salmonella detection. Analyses were realized on colon content and swabs of carcass for each pig. Two isolates by positive samples were serotyped and typed by PFGE using XbaI enzyme. All S. Typhimurim and monophasic variant of serovar Typhimurium were subtyped by MLVA. Prevalence of Salmonella in colon content was higher for organic pigs, 37.9% IC95than for conventional pigs, 32.7% but difference was not significant (p=0.563). Salmonella prevalence was lowest on carcasses and very close between the two productions: 10.7% for organic and 10.3% for conventional. The 104 isolates were distributed in 7 serovars: Derby (46 isolates), Brandenburg (18), Typhimurium (13), monophasic variant of Typhimurium 4,12:i:- (11) and 4,5,12:i:- (10), Infantis (2) and Mbandaka (2). Sixteen PFGE profiles were obtained: 1 per serovar for serovars Mbandaka, Infantis, and Brandenbrug, 3 for Derby, 4 for Typhimurium and 4 for monophasic variant 4,12:i:-. Seven PFGE profiles, representing 84% of the isolates, were common between organic and conventional pigs. A major profile gathered 79% of the S. Derby strains. S. Brandenburg strains were also very clonal, all presented the same PFGE profiles whereas they came from 5 different herds. With 20 isolates from 12 carcasses, it has not been possible to show with certainty Salmonella cross-contamination between organic and conventional pigs during the process. For S. Typhimurium, MLVA gave a better discrimination than PFGE, 8 patterns against 4; particularly for 6 isolates with the same PFGE pattern which was subdivided into 5 MLVA patterns. While on the 21 monophasic isolates, MLVA and PFGE gave similar discrimination (7 patterns with MLVA and 6 with PFGE)

Récit historique et objet technique : outil de valorisation mutuelle

National audienceDans le domaine de l’histoire des techniques et du patrimoine matériel, l’informatisation est massive, autant sur le plan de l’écriture, que des sources (archives) ou de la valorisation. Cependant les articulations entre ces plans (archive, recherche, valorisation) restent faibles. Ce travail propose un outil numérique de gestion de contenu historique (récits et sources) pour documenter et valoriser les objets du patrimoine technique. En fonction des situations, différentes interfaces permettent d’accéder aux connaissances, une interface de navigation en 3D est ici proposée en exemple. L’objet technique et le travail de l’historien sont conjointement valorisés