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

Probing the physics of the intracluster medium

McCarthy, Ian G. 10 April 2008 (has links)
No description available.

Les clusters, innovation et développement territorial / Clusters, innovation and territorial development

Khattabi, Mohamed Aissam 23 February 2012 (has links)
L’objectif de ce travail est d’expliciter en premier lieu l’évolution théorique des clusters depuis le XIXème (District marshallien) jusqu’aux clusters d’aujourd’hui, les pôles de compétitivité français ; et d’étudier en deuxième lieu les caractéristiques, les déterminants et les effets des clusters en général sans négliger et oublier de traiter le côté pratique des clusters dans le monde (France, Etats-Unis, Japon, Corée de Sud et l’Inde). Ainsi, la pratique nous montre qu’il y a des liens et des interdépendances réciproques entre les clusters et l’innovation. A cet effet, nous déduisons que les clusters constituent l’écosystème, l’environnement et l’organisation la plus favorable à l’innovation, grâce aux effets des proximités croisées que les clusters réunissent et au capital social créé et développé en son sein entre les parties prenantes des clusters. A partir de là, nous comprendrons bien que les clusters agissent ou ont un effet sur leur territoire d’implantation du fait de tous les éléments (proximités, innovations, capital social…), les intervenants et les acteurs locaux qu’ils réunissent. Donc, ils impactent d’une manière globale le développement territorial et en particulier la compétitivité et l’attractivité territoriale ; tout cela d’une manière endogène ou exogène. Autrement dit, le développement territorial par les clusters est basé sur des ressources « glocales » c’est-à-dire d’origine endogène et exogène en même temps. / The purpose of this work is to clarify firstly the theoretical evolution of clusters since the nineteenth (Marshallian District) to today's clusters, French competitiveness clusters, and secondly, to study the characteristics, determinants and clusters effects in general without neglecting or forgetting to treat the practical side of clusters in the world (France, USA, Japan, South Korea and India).Thus, practice shows that there are links and reciprocal interdependencies between clusters and innovation. To this end, we infer that clusters constitute the ecosystem, the environment and the most conducive organization for innovation, due to effects of cross proximities that clusters gather and social capital created and developed within, between clusters stakeholders.From there, we understand that the clusters act or have an effect on their implantation territory due to all of the elements (proximities, innovations, social capital ...), stakeholders and local actors they assemble. Thus, they impact the territorial development in a global way, and the competitiveness and territorial attractiveness in particular ; all this in an endogenous or exogenous way. In other words, territorial development by the clusters is based on "glocal" resources, i.e. they have endogenous and exogenous origin at the same time.


Glaspey, John Warren, 1944- January 1971 (has links)
No description available.

Catalysis of colloidal transition metal nanoparticles in aqueous medium

Li, Yin 12 1900 (has links)
No description available.

Synthesis and characterization of novel group 13 tridecameric inorganic nanoclusters /

Gatlin, Jason Trevor, January 2007 (has links)
Thesis (Ph. D.)--University of Oregon, 2007. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 233-262). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.

Examination of Abell Clusters of Galaxies in Local Supercluster Environments

Krughoff, Karl Simon January 2004 (has links) (PDF)
No description available.

The faint end of the luminosity function in clusters of galaxies

De Propris, Roberto 13 July 2018 (has links)
We have determined luminosity functions, surface density distributions and color distributions for galaxies in eight clusters of galaxies at moderate redshift (z ~ 0.02) observed at the CFHT. 1) In the inner 2' of four cD clusters (Abell 2052, 2107, 2199 and 2666) we find very steep LFs, with α ~ -2.2 ± 0.2, where [special characters omitted](L) α Lα, where L is luminosity 2) For Abell 262, we find no significant contribution from cluster dwarfs in the field around NGC708 (the central cluster elliptical), although there is a small excess over background counts in the inner 3' of this field. For galaxies near UGC1308, we derive a LF with α ~ -1.4 ± 0.1. Galaxies in this field are concentrated towards UGC1308, so that the LF may be due to a population of satellites. 3) For the field centred on NGC1275 in Abell 426 we find a very steep LF, with α ~ -1.9 ± 0.1. We find that galaxies are not centrally concentrated towards NGC1275, except for a central ‘spike’ in their surface density distribution. We see a weak sequence of galaxies in the V vs V - I plot. There is a small color gradient in the sense of bluer galaxies near NGC1275. 4) For the field centred on NGC1265, we find again a very steep LF. Galaxies in this field tend to avoid the neighbourhood of NGC1265 and there is a mild red color gradient towards NGC1265. The LF within 100 kpc of NGC1265 is somewhat flatter than outside of this region, although the significance of this result is marginal. 5) For the field centred on UGC3274 in A539 we find a LF with α ~ -1.4 ± 0.1. We see that the galaxy distribution as a function of distance from UGC3274 is flat, except for a central spike. The LF appears to steepen towards UGC3274. There is a tight sequence of cluster galaxies in the V vs. V - I plot. There also appears to be a blueing trend towards UGC3274. 6) For Hercules (A2151) we derive a LF with α ~ -1.5 and M* = 12.2, where M* is a characteristic luminosity here converted to magnitudes. We interpret these results as supporting the conclusions by Biviano et al. (1995b) in Coma, namely that a population of dwarf galaxies with a steep LF constitutes the main body of the cluster, into which brighter giants fall later, thereby flattening the LF. We also find evidence that steep LFs are correlated with high gas densities. The blueing trend towards NGC1275 and UGC3274 is also consistent with recent star formation in dwarfs due to accretion of intracluster gas. / Graduate

A photometric and morphological study of compact groups of galaxies and their environments

Kindl, Enrico January 1987 (has links)
This thesis examines properties of galaxies in and around compact groups. Astrometry, photometry and morphological classifications are derived from CCD images for all 463 galaxies in Hickson's sample of 100 compact groups. Some minor revisions to the membership of the original catalog are made. At high galactic latitude (b > 30°), the catalog is estimated to be 90% complete for groups with total B[formula omitted] magnitude 13.0 or less. 49% of all the catalogued galaxies, and 48% of first-ranked galaxies are spiral. No significant difference is found between the distribution of morphological types of first-ranked galaxies and all group galaxies. Morphological concordance occurs among galaxies within a group: more galaxies are the same type (spiral or nonspiral), than would be expected by chance. Galaxy morphological type correlates with group optical luminosity and, more strongly, with velocity dispersion, but not with galaxy space density. These results imply that the morphological types of galaxies in compact groups are strongly influenced by the environment, and that this influence occurs mostly at the time of galaxy formation. Fields surrounding 97 compact groups with known redshifts were examined on the Palomar Observatory Sky Survey prints. 3889 galaxies were identified within 1.125h⁻¹ Mpc of the centre of each group. Coordinates, magnitudes, diameters, and Hubble types are derived for these galaxies. 78% of the groups show no significant excess of field galaxies within 0.5h⁻¹ Mpc. This indicates that most compact groups are truly isolated. 59% of these field galaxies were classified as spiral, a higher fraction that for the group galaxies. This difference is more pronounced for groups which do show a significant field galaxy excess. These results indicate that most groups are dense dynamical entities. Monte-Carlo calculations indicate that 35% of galaxy quintets are predicted to contain a single discordant redshift due to the chance alignment of an unrelated field galaxy. This is in agreement with the observed number of four discordant quintets in 10. These results are consistent with the cosmological interpretation of galaxy redshifts. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Les tensions coopération/concurrence au niveau local/global et leur articulation au sein des réseaux d’innovation : le cas des secteurs de haute technologie en Europe / Tensions cooperation/competition and local/global and their articulation within innovation networks : the case of high-tech sectors in Europe

Hakizimana, Bonaventure 08 July 2014 (has links)
Au cours du XXIeme siècle, les clusters ont émergé comme un élément central desdébats économiques, par exemple en ce qui concerne leur rôle sur la croissanceéconomique. Diverses études académiques sur les clusters et réseaux d'innovation ontproduit un large éventail d'approches dans ce domaine. Les chercheurs ont tenté dedéfinir les concepts des clusters et réseaux d’innovation et d'analyser le cadre de lacoopération / concurrence au niveau local ou global.L'objectif de cette thèse est d'étudier un aspect spécifique des clusters, à savoir la tensionpotentielle entre coopération et concurrence et entre les activités au niveau local et global.Nous soutenons que la relation antagonistique entre la coopération et la concurrence n’apas été jusqu'à présent suffisamment étudiée, bien que la tension sous-jacente puisse êtreclairement identifiée et a joué un rôle important dans l'évolution des valeurs sociétalespréconisant ce comportement compétitive ou coopérative. Dans le cadre des clusterséconomiques, la tension se manifeste dans des comportements qui combinent deséléments de la concurrence et de la coopération, par exemple, si une entreprise décide decoopérer avec un concurrent pour être en mesure d'observer de près la menace de leursaffaires que ce concurrent représente. Grâce à une analyse qualitative et quantitative, la thèse a prêté plus d'attention à cescomportements hybrides de « coopétition glocal » permet une meilleure compréhensiondu comportement des entreprises dans des réseaux d’innovation. Nous proposons denouvelles méthodes et concepts concernant la représentation de la notion de«concurrence» et soulignons l’utilité de la notion de « coopétition globale » pourcomprendre le comportement des entreprises telles que la coopération antagonistique.Nos résultats montrent que la coopétition est une stratégie originale pour gérer laconcurrence du marché et implique de travailler avec des concurrents afin de capturersouvent des avantages communs. Notre recherche empirique a analysé les déterminantssous-jacents de ces comportements et les relie aux caractéristiques des clusters enfonction de leur structure d’information, leurs types de coopération, les compétencesdisponibles et l'échelle géographique du marché. / Over the last decades, clusters have emerged as a central element of economic debates,for instance as regards their on role in economic growth. Various academic studies onclusters and innovation networks have produced a wide range of approaches in this area.Scholars have attempted to define the concepts of clusters and innovation networks andanalyze the framework of cooperation / competition at the local or global level.The objective of this thesis is to explore a specific aspect of clusters, namely the potentialtension between cooperation and competition and between activities at the local andglobal level. We argue that the antagonistic relationship between cooperation andcompetition have so far not sufficiently studied, although the underlying tension can beclearly identified and has played a significant role in changing societal values advocatingeither competitive or collaborative behavior. In the context of economic clusters, thetension manifests itself in behaviors that combine elements of both competition andcooperation, for instance if a company decides to cooperate with a competitor only to beable to observe closely the threat to their business threat that this competitor represents.Through qualitative and quantitative analysis, the thesis shows that paying more attentionto such hybrid behaviors of ‘glocal coopetition’ provides a better understanding of firmbehavior in innovation networks. We propose new methods and concepts regarding therepresentation of the concept of "competition" and stress the usefulness of the idea of‘global coopetition’ for understanding firm behavior such as antagonistic cooperation.Our results underline that coopetition is an original strategy for managing marketcompetition and often entails working with competitors in order to capture a commonbenefits. Our empirical research analyses the underlying determinants for these behaviorsand links them to the characteristics of clusters in terms of their information structure,type of cooperation, available skills and geographic scale of the market.

Study of the structural and electronic properties of aluminum nano clusters by DFT

Raparla, Mrudula. January 2009 (has links)
Thesis (M.S.)--University of Texas at El Paso, 2009. / Title from title screen. Vita. CD-ROM. Includes bibliographical references. Also available online.

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