La recherche vise à appréhender la perception de la notion de performance par les acteurs composants les Réseaux Territorialisés d’Organisations (RTO), non pilotés par une firme leader, mais comportant des instances de gouvernance stratégique. Malgré une littérature abondante portant sur les RTO, les recherches portant sur la perception de leur performance sont encore émergentes. Soutenue par un cadre interprétatif visant à clarifier ce que peut recouvrir le concept de performance dans un RTO, la recherche, mobilisant la théorie des représentations sociales, explore au moyen de la méthodologie des cartes cognitives les perceptions d’acteurs hétérogènes composant les RTO portuaires français. 36 entretiens ont été menés auprès des acteurs des Grands Ports Maritimes français. Les résultats montrent principalement qu’il existe des représentations partagées assez limitées du point de vue des métas-critères et déterminants de performance, avec toutefois l’existence de logiques communes, déclinées en paradigmes et classes de représentations. Les résultats montrent également la focalisation fréquente des perceptions sur un très faible nombre d’acteurs clés de la chaîne servicielle. L’étude conclut sur les perspectives pour le contrôle de gestion dans ces RTO. / The research aims to understand the perception of the performance concept by cluster actors. We focus on clusters which are not controlled by a leading firm, but include strategic governance institutions. Despite a vast literature on clusters, researches on the perception of their performance are still emerging. Supported by an interpretative framework to clarify what can cover the concept of performance in a cluster, this research, mobilizing social representation theory, explores the perception of heterogeneous actors composing French seaports, using the methodology of cognitive maps. 36 interviews were conducted with participants of the main French Seaports. The results show that the shared representations are fairly limited in terms of meta-criterias and performance determinants, but identifies common logics, paradigms and representations classes. The results also show that there is a frequent focalisation of the perceptions on very few keys actors involved in the service chain. The study concludes on the management control perspectives in these clusters.

Galaxy clusters, the largest gravitationally-bound structures in the universe, are composed of 50-1000s of galaxies, hot X-ray emitting gas, and dark matter. They grow in size over time through cluster and group mergers. The merger history of a cluster can be imprinted on the hot gas, known as the intracluster medium (ICM). Merger signatures include shocks, cold fronts, and sloshing of the ICM, which can form spiral structures. Some clusters host double-lobed radio sources driven by active galactic nuclei (AGN). First, I will present a study of the galaxy cluster Abell 2029, which is very relaxed on large scales and has one of the largest continuous sloshing spirals yet observed in the X-ray, extending outward approximately 400 kpc. The sloshing gas interacts with the southern lobe of the radio galaxy, causing it to bend. Energy injection from the AGN is insufficient to offset cooling. The sloshing spiral may be an important additional mechanism in preventing large amounts of gas from cooling to very low temperatures. Next, I will present a study of Abell 98, a triple system currently undergoing a merger. I will discuss the merger history, and show that it is causing a shock. The central subcluster hosts a double-lobed AGN, which is evacuating a cavity in the ICM. Understanding the physical processes that affect the ICM is important for determining the mass of clusters, which in turn affects our calculations of cosmological parameters. To further constrain these parameters, as well as models of galaxy evolution, it is important to use a large sample of galaxy clusters over a range of masses and redshifts. Bent, double-lobed radio sources can potentially act as tracers of galaxy clusters over wide ranges of these parameters. I examine how efficient bent radio sources are at tracing high-redshift (z>0.7) clusters. Out of 646 sources in our high-redshift Clusters Occupied by Bent Radio AGN (COBRA) sample, 282 are candidate new, distant clusters of galaxies based on measurements of excess galaxy counts surrounding the radio sources in Spitzer infrared images.

La presente investigación, se enfoca en los clusters ambientales y su implementación legal en nuestro país, teniendo en cuenta que un cluster es una concentración geográfica de empresas, instituciones y cadenas productivas, que cooperan para lograr un objetivo común, será necesario exponer en primer lugar el rol que presentan las empresas en materia de medio ambiente, para ello, el primer capítulo muestra el marco normativo ambiental general, así como el grado de responsabilidad que tiene el privado en relación al ambiente, enfatizando que el modelo clásico de regulación ambiental debe ceder el paso a una regulación más dinámica, mostrando modelos como la autorregulación y la importancia que presentan las ecoauditorias para las empresas en el cumplimiento de las responsabilidades con el medio ambiente. Atendiendo al particular rasgo cooperativo que se da en un cluster entre los distintos agentes económicos, abordaremos en el segundo capítulo la cooperación existente entre los niveles público y privado en relación al medio ambiente, con ello, se explora los modelos aplicados en los sistemas federales y unitarios, demostrando que estos sistemas presentan importantes similitudes, haciendo factible la aplicación nacional de modelos regulatorios extranjeros, de esta manera, se expone formas de regulación más flexibles, que permiten acercar las políticas ambientales a la realidades particulares, plasmando en la normativa las prioridades que presentan tanto empresas privadas como sociedad civil en relación a una problemática ambiental en concreto y su posible solución, debido al particular grado de cooperación que se da estos modelos. Por último, el tercer capítulo expone el potencial medioambiental del clusters, enfatizando el rol fundamental que presenta el Estado para poder hacer posible que un cluster ambiental genere los resultados deseados, tanto a nivel de política ambiental como económica, requiriendo para ello, un grado de cooperación que se traduzca en incentivos necesarios así como una regulación dinámica que permitan traducir las particularidades de cada realidad regional, en lo productivo y lo ambiental, llegando a concluir que este modelo es viable en nuestro país.

Two classes of trimetal nitride metallofullerenes, Sc3N@C n (n=68, 78) and MxSc3-xN@C80 (x=0-2), are investigated by Density Functional Theory with respect to their electronic properties and related geometric, energetic, and magnetic features. The substantial electron transfer from the metallic core to the fullerene cage makes these systems promising candidates for nonlinear optical devices. Pronounced magnetic effects associated with complexes that enclose lanthanide constituents suggest their suitability as contrast agents in biomedical imaging.

This research, conducted via interviews at 32 biotechnology firms, which provide rare information on actual firm interactions, elucidates the factors that influence the location and growth of the biotechnology sector in a typical American metropolitan area. Results indicate that most of the biotechnology firms within the Cincinnati region are there because of entrepreneurial ties with universities and research hospitals in the area, not because the region has specific advantages for biotechnology firms compared to other metropolitan areas of similar size. The authors find that interfirm linkages range from extremely weak to nonexistent. No specialized labor force exists to support biotechnology firms, nor are there specialized infrastructure and business services. No biotechnology-dedicated government office exists. In summary, the authors see more colocation than interactive clustering of biotechnology firms, implying that economic development efforts to enhance interfirm linkages are likely to be less effective than support for hospital and university research and education.

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Recent experiments have shown that Ta@Si16+ is a very stable cation from which it should be possible to create Si-based cluster assembled materials. In this paper we have studied, by means of first-principles spin-dependent generalized gradient approximation calculations, the structural and electronic properties of the following systems: (i) Ta@Sin+ clusters in the range n = 14–18; (ii) (Ta@Si16F)m aggregates with sizes m = 1–8 formed by Ta@Si16F molecules; (iii) infinite wires formed by stacking triangular (Ta@Si16F)3 aggregates twisted 60◦ to each other along the vertical axis; and (iv) the fcc phase of bulk Ta@Si16F. The minimum-energy Ta@Si16+ cluster shows C3v symmetry, having 40 meV smaller total energy than a fullerenelike D4d isomer. However, the molecule Ta@Si16F formed with that D4d isomer is 40 meV more stable than that formed with the C3v one. We have optimized several [Ta@Si16F]n aggregates (n = 1–8) which contain the Ta@Si16 unit with D4d symmetry. The more bound (Ta@Si16F)6 aggregate is formed by stacking vertically two triangular (Ta@Si16F)3 aggregates which are twisted 60◦ to each other. The infinite wire formed with that (Ta@Si16F)6 aggregate as the unit cell has a cohesive energy 1.88 eV and a small highest occupied molecular orbital–lowest occupied molecular orbital gap. We have optimized also a metastable fcc bulk phase having the Ta@Si16F supermolecule as the unit cell. A Birch-Murnaghan fit to that phase produces a cohesive energy 0.84 eV at lattice constant 12.27 A, with bulk modulus 7.55 GPa and a phase stability to isotropic compression smaller than 0.75 GPa. That phase is nonmagnetic and shows a band gap of 0.20 eV. Using the values of hardness of Ta@Si16F molecules, we estimated a correction enhancement factor ∼3 to that small band gap. For that metastable solid we performed a 13.5-ps run of first-principles molecular dynamics annealing at 300 K and constant volume, and we found that the Ta@Si16F supermolecule in the fcc cell becomes severely distorted after the first 5 ps.

Using the redMaPPer catalog of 21709 galaxy clusters and photometric information for 455946 galaxies from SDSS DR8, we study the effects of local and global environment on galaxy evolution within clusters in the redshift range 0.2 ≤ z ≤ 0.5 and the richness range 20 ≤ λ ≤ 236. We use cluster richness λ as a proxy for global environment and cluster-centric radius dBCG to represent the local environ- ment within clusters. We measure giant-to-dwarf ratio (GDR) which gives insight regarding the composition of the red sequence, and we measure red fraction which holds information about the rate at which galaxies falling into clusters cease to form new stars and build up the red sequence in a phenomenon called quenching. We ob- serve that red fraction decreases with redshift, increases with λ, and decreases with dBCG. GDR, meanwhile, decreases with redshift, does not vary significantly with λ, and decreases with dBCG. All together, our results tell the story of clusters starting with bright, massive galaxies which accrete smaller and smaller galaxies over time. The galaxies are quickly quenched upon entering clusters environment. We observe that most quenching occurs on smaller richness scales than our data covers, and that by the time clusters have grown to the richnesses redMaPPer is sensitive to, ram pressure stripping is likely to be the dominant quenching mechanism. / Graduate

This dissertation contains three essays on debts of different forms that make contributions to the areas of international macroeconomics and spatial economics. In particular, the first two essays study sovereign debts. They examine sovereign default behaviors together with interactions between sovereign defaults and countries’ costs of borrowing. The third essay looks at bank loans. It explores the possibility of understanding economic agglomeration through distance-related financial frictions firms face when borrowing from banks.

Developing chemical bonding models in clusters is one of the most challenging tasks of modern theoretical chemistry. There are two reasons for this. The first one is that clusters are relatively new objects in chemistry and have been extensively studied since the middle of the 20th century. The second reason is that clusters require high-level quantum-chemical calculations; while for many classical molecules their geometry and properties can be reasonably predicted by simpler methods. The aim of this dissertation was to study doped clusters and explain their chemical bonding. The research was focused on three classes of compounds: aluminum clusters doped with one nitrogen atom, planar compounds with hypercoordinate central atom, partially mixed carbon-boron clusters, and transition metal clusters. The geometry of the two latter classes of compounds was explained using the concept of aromaticity, previously developed in our group.