Experimental investigation of phase equilibria in the ZrCu-Al system at 500º C

Weight is of a fundamental importance in the performance of aircraft. Finding new materials for the structural elements of an aircraft that are lighter while giving the performance needed is crucial. Al alloys are commonly utilized materials because of their relatively low density and good mechanical properties. This is why the Zr-Cu-Al ternary system has been chosen in this study. There is no agreement on the shape of the isothermal phase diagram of this system. This study has the goal of adding some light on this matter, by finding yet another result that can help us understand better this system. In this study the isothermal section of the Zr-Cu-Al system at 500 ºC is experimentally determined

HfS, Hyperfine Structure Fitting Tool

Hyperfine Structure Fitting (HfS) is a tool to fit the hyperfine structure of spectral lines with multiple velocity components. The HfS_nh3 procedures included in HfS simultaneously fit the hyperfine structure of the NH3 (J, K) = (1, 1) and (2, 2) transitions, and perform a standard analysis to derive ${T}_{\mathrm{ex}}$, NH3 column density, ${T}_{\mathrm{rot}}$, and ${T}_{{\rm{k}}}$. HfS uses a Monte Carlo approach for fitting the line parameters. Special attention is paid to the derivation of the parameter uncertainties. HfS includes procedures that make use of parallel computing for fitting spectra from a data cube

Reflexió sobre l'economia i el territori a Catalunya

Le College dees Économistes de la Catalogne a organisé au mois de Novembre de 1989 des Journées sur le présent et l'avenir de l'économie Catalane qui ont compris un cycle de tables rondes autour de sujets fonamentaux sur la situtation actuelle et les perspectives économiques, sociales et territoriales de la Catalogne. Les grands sujets-clé ont été: «Cavenir économique de la Catalogne dans le contexte espagnol et européen», «Captitude financiere de la Catalogne», «La production d'idées économiques en Catalogne», «Les aspects institutionnels dans la vie économique de la Catalogne» et «Economie et territoire: vers un modele de croissance équilibré?».In November 1989, the Catalan College of Economists held a conference on the present and future of the Catalan Economy. A series of round table meetings dealt with the fundamental topics related to the present economic, social and regional situation and Catalonia's perspectives for the future. The main questions posed were: the future of Catalonia's economy in the Spanish and European context; the proposal of ideas in the field of economics in Catalonia; the financial capacity of Catalonia; institutional aspects of the economic life of Catalonia and the possibility of a model of balanced growth.El Colegio de Economistas de Cataluña realizó el mes de noviembre de 1989 unas Jornadas sobre el presente y futuro de la Economia catalana. Las jornadas consistieron en un ciclo de mesas redondas acerca de los temas fundamentales relatives a la situaci6n actual y a las perspectiva~ económicas, sociales y territoriales de Cataluña. Los grandes temas-clave fueron: el futuro económico de Cataluña en el contexto español y europeo; la generaci6n de ideas económicas en Cataluña; los aspectos institucionales de la vida economica en Cataluña; y economia y territorio: hacia un modelo de crecimiento equilibrado?El Col·legi d'Economistes de Catalunya va realitzar el mes de novembre de 1989 unes Jornades sobre el present i futur de l'Economia catalana. Les jornades consistiren en un cicle de taules rodones al voltant dels temes fonamentals relatius a la situació actual i a les perspectives economiques, socials i territorials de Catalunya. Els grans temes -clau varen ser: el futur economic de Catalunya en el context espanyol i europeu; la generació d'idees economiques a Catalunya; l'aptitud financera de Catalunya; els aspectes institucionals en la vida econbmica de Catalunya i economia i territori: vers un model de creixement equilibrat

Hope assemblages. An ethnography of passionate blogging

Internet y las tecnologías digitales han estado acompañadas de promesas de futuro desde su nacimiento. En este artículo nombro esa particular orientación hacia el porvenir con el concepto de esperanza y exploro la heterogeneidad de entidades que toman parte en su emergencia. Lo hago a través de una etnografía de bloggers apasionados, individuos que bloguean de manera intensiva, reflexivos con su práctica y comprometidos con la transformación de la sociedad. Presento y discuto la producción de expectativas que acompañan a su esperanza y me refiero a dos aspectos clave en su emergencia. Primero la performación de intensas temporalidades en el bloguear en las que interviene la infraestructura material de la Blogosfera, a través de ella la producción de hechos del pasado proporciona las condiciones de posibilidad para la elaboración de expectativas de futuro. Segundo, conceptualizo la esperanza de los bloggers como un ensamblaje heterogéneo que produce la desestabilización de la ontología del presente al abrir espacios de posibilidad futura.The Internet and digital technologies have been accompanied by promises of future since their birth. I use the concept of hope in this article to refer to this particular orientation towards the future. I elaborate my argument drawing on ethnography of passionate bloggers, individuals that blog intensively, that are highly reflective with their practice and are engaged with the transformation of society. I present and discuss the production of expectations that accompany their hope and point out to two key issues in its coming into being. First, I refer to the performance of intense temporalities in blogging and discuss the decisive role of the Blogosphere infrastructure in this instance, it is by producing past facts that infrastructure provide the conditions of possibility for elaborating future expectations. Second, I conceptualize bloggers’ hope as a heterogeneous assemblage that destabilizes the ontology of the present by opening spaces of future possibility

Anonimous cowar. Conflicts due to open participation in a colaborative comunity Simetric ethnography of a cooperative weblog focused in the news’s production through filtering

The present study is the result of an ethnographic research in a cooperative weblog, an open community where anybody can participate. The community’s objective of news’s productio relies in a colaborative system of filtering thouigh which the community hierarchize users’s contributions. Through this filtering system and through the registry mechanism (by which users create a permanent identity) the community segments information’s visibility and credibility depending on the user’s identity, whter he is a registered user or an anonomous one. The study demonstrates how the filtering processes not only hierarchize the information but organize and structre the community.El presente estudio es el resultado de la investigación etnográfica de un weblog colaborativo. Un entorno abierto a la participación y libre expresión de cualquier usuario. La comunidad tiene como objetivo la producción de noticias significativas, para lo cual recurre a un sistema colectivo de filtrado de la información que sirve para jerarquizar las contribuciones de los usuarios. A través de este sistema de filtrado y mediante el mecanismo de registro (por el que los usuarios crean una identidad permanente) la comunidad segmenta la visibilidad y credibilidad de las informaciones según procedan de usuarios registrados o anónimos. El estudio demuestra que los procesos de selección y filtrado no sólo jerarquizan la información, sino que organizan y estructuran socialmente a la comunidad

L'estructuració del territori per la propietat de la terra. El cas de la "província" de Girona

Le but de ce travail est l'étude de la configuration d'un espace juridique, celui de la propiété foncière, qui est en méme temps un espace générateur d'excédent dans le cadre de la production agraire. On est parti de l'hypothèse que cet espace spécifique s'organise en suivant le modèle de la valorisation du capital et qui répond à la "théorie des lieux centraux" de W. Christaller. La confirmation de cette hypothèse, dans le cadre de la province de Gérone, a permis de tirer la conclusion qu'il existe un rapport étroit entre la taille d'une commune et l'étendue des propriétés foncières de ses habitants. Les résultats obtenus permettent d'affirmer qu'il existe cinq niveaux d'accumulation d'excédents agraires échelonnés hyérarchiquement. On a pu aussi établir des aires d'extraction des excédents pour chacun des centres des cinq niveaux, l'étendue de ces aires étant en rapport avec la taille des centres, de sorte qu'il existe une hyérarchisation des aires en fonction des différents niveaux. C'est ainsi qu'on a pu tracer sur des cartes les limites des aires de dépendance de chacun des niveaux. On doit d'ailleurs souligner que, dans le cas de la province de Gérone, les niveaux hyérarchiques ne jouent pas toujours le méme rôle dans la structuration territoriale: ainsi dans cer tains cas (le pays de la Garrotxa, par exemple) c'est le niveau I qui structure le territoire tandis que dans d'autres contrées (La Selva notamment) c'est le niveau III qui aura ce même rôle.The objective of this study is the analysis of the configuration of a juridical unit, that of land property, a unit which generates a surplus of agricultural production. The analysis has been applied to the province of Girona. It has been presumed that the structure of this specific unit corresponds to the same model as that which conforms to capital valuation, as in W. Christaller's central place theory. On. testing the validity of this hypotesis, it has been possible to conclude that there exists a close relationship between the size of a population nucleus and the size of the agricultural properties of its inhabitants. Likewise, the results obtained make it possible to assert the existence of a series of five successively ranked levels of accumulation of agricultural surplus. It has also been possible to identify an area of surplus extraction for each centre and at each level; and to demonstrate that the size of these areas is related to the size of the centre, and likewise, that their size varies according to level

The molecular condensations ahead of Herbig-Haro objects. II: a theoretical investigation of the HH 2 condensation

Clumps of enhanced molecular emission are present close to a number of Herbig-Haro (HH) objects. These enhancements may be the consequence of an active photochemistry driven by the UV radiation originating from the shock front of the HH object. On the basis of this picture and as a follow up to a molecular line survey toward the quiescent molecular clump ahead of the HH object, HH 2 (Girart et al. 2002), we present a detailed time and depth dependent chemical model of the observed clump. Despite several difficulties in matching the observations, we constrain some of the physical and chemical parameters of the clump ahead of HH 2. In particular, we find that the clump is best described by more than one density component with a peak density of 3 × 105 cm-3 and a visual extinction of ≤3.5 mag; its lifetime can not be much higher than 100 years and the impinging radiation is enhanced with respect to the ambient one by probably no more than 3 orders of magnitude. Our models also indicate that carbon-bearing species should not completely hydrogenate as methane when freezing out on grains during the formation of the clump