3,032 research outputs found
Research support: models and professionalisation
This presentation was given by Mr Simon Kerridge, Secretary of the Association of Research Managers and Administrators (ARMA), at the BRAM-NET Annual Event on the 17th February 2011. The event was organised by Dr Rosa Scoble and hosted at Brunel University. BRAM-NET (The Brunel Research Administrators & Managers Network) is a forum to share best practice and information on new initiatives between colleagues supporting research in the centre and academic areas at Brunel University
Torsional solutions of convection in rotating fluid spheres
A numerical study of the nonlinear torsional solutions of convection in rotating, internally heated, self-gravitating fluid spheres is presented. Their dependence on the Rayleigh number has been found for two pairs of Ekman (E) and small Prandtl (Pr) numbers in the region of parameters where, according to Zhang et al. [J. Fluid Mech. 813, R2 (2017)], the linear stability of the conduction state predicts that they can be preferred at the onset of convection. The bifurcation to periodic torsional solutions is supercritical for sufficiently small Pr. They are not rotating waves, unlike the nonaxisymmetric case. Therefore they have been computed by using continuation methods for periodic orbits. Their stability with respect to axisymmetric perturbations and physical characteristics have been analyzed. It was found that the time- and space-averaged equatorially antisymmetric part of the kinetic energy of the stable orbits splits into equal poloidal and toroidal parts, while the symmetric part is much smaller. Direct numerical simulations for E=10-4 at higher Rayleigh numbers (Ra) show that this trend is also valid for the nonperiodic flows and that the mean values of the energies remain almost constant with Ra. However, the modulated oscillations bifurcated from the quasiperiodic torsional solutions reach a high amplitude, compared with that of the periodic, increasing slowly and decaying very fast. This repeated behavior is interpreted as trajectories near heteroclinic chains connecting unstable periodic solutions. The torsional flows give rise to a meridional propagation of the kinetic energy near the outer surface and an axial oscillation of the hot nucleus of the metallic fluid sphere.Postprint (published version
Anti-bribery and corruption reporting disclosures
Part of a series of research projects which analyses disclosures on areas of non-financial performance by Australian Securities Exchange (ASX) companies.Publisher PD
RAIN
Volume 14, Number 2
Inside: Working Communities; Community Supported Agriculture; Downtown Community Television; Workbikes and Society; Self-Reliance and Activism in India; Real and Imagined Communities; Cities Against Centralization; Neighborhood Controlled Food and Transport; Direct Self-Government; Respected Local Labor
RAIN began in October 1974 as a publication of ECO-NET, an environmental education network funded by the Hill Foundation and an Environmental Education grant. Its office was based in the Environmental Education Center at Portland State University. With a focus on the Pacific Northwest, particularly Oregon, RAIN originally described itself as a “bulletin board” with an “emphasis on environmental/energy related and communications kinds of information” and interested in “the evolutionary possibilities of inter-disciplinary connections.”https://pdxscholar.library.pdx.edu/rain_japt/1099/thumbnail.jp
Relacions de la medicina catalana amb les diferents escoles mèdiques d'Europa i Amèrica durant el període 1890-1939
RAIN
Volume 7, Number 10
Inside: Lost Latin Ecotopia; The Values of Waste
RAIN began in October 1974 as a publication of ECO-NET, an environmental education network funded by the Hill Foundation and an Environmental Education grant. Its office was based in the Environmental Education Center at Portland State University. With a focus on the Pacific Northwest, particularly Oregon, RAIN originally described itself as a “bulletin board” with an “emphasis on environmental/energy related and communications kinds of information” and interested in “the evolutionary possibilities of inter-disciplinary connections.”https://pdxscholar.library.pdx.edu/rain_japt/1067/thumbnail.jp
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West African monsoon 2012
Living up to its reputation as a highly variable climate system, the West African Monsoon (WAM) 2012 contrasted strikingly with the previous year. In 2011, the West African rainy season was delayed, patchy, and irregular. In 2012, whilst it was anomalously wet in many area, the Guinea coastal countries and some crucial agricultural regions remained very dry, persisting from the previous year. As a result, 2012 generated the third big food crisis to hit the region in the last seven years. The 2012 WAM forecast, observed climate conditions and the ongoing socio-economic implications for the region are reviewed here
Periodic orbits in tall laterally heated rectangular cavities
This study elucidates the origin of the multiplicity of stable oscillatory flows detected by time integration in tall rectangular cavities heated from the side. By using continuation techniques for periodic orbits, it is shown that initially unstable branches, arising at Hopf bifurcations of the basic steady flow, become stable after crossing Neimark-Sacker points. There are no saddle-node or pitchfork bifurcations of periodic orbits, which could have been alternative mechanisms of stabilization. According to the symmetries of the system, the orbits are either fixed cycles, which retain at any time the center symmetry of the steady flow, or symmetric cycles involving a time shift in the global invariance of the orbit. The bifurcation points along the branches of periodic flows are determined. By using time integrations, with unstable periodic solutions as initial conditions, we determine which of the bifurcations at the limits of the intervals of stable periodic orbits are sub- or supercritical.Postprint (author's final draft
Architectural Model for Evaluating Space Communication Networks
[ANGLÈS] The space exploration endeavor started in 1957 with the launch and operation of the first manmade satellite, the URSS Sputnik 1. Since then, multiple space programs have been developed, pushing the limits of technology and science but foremost unveiling the mysteries of the universe. In all these cases, the need for flexible and reliable communication systems has been primordial, allowing the return of collected science data and, when necessary, ensuring the well-being and safety of astronauts. To that end, multiple space communication networks have been globally deployed, be it through geographically distributed ground assets or through space relay satellites. Until now most of these systems have relied upon mature technology standards that have been adapted to the specific needs of particular missions and customers. Nevertheless, current trends in the space programs suggest that a shift of paradigm is needed: an Internet-like space network would increase the capacity and reliability of an interplanetary network while dramatically reducing its overall costs. In this context, the System Architecting Paradigm can be a good starting point. Through its formal decomposition of the system, it can help determine the architecturally distinguishing decisions and identify potential areas of commonality and cost reduction. This thesis presents a general framework to evaluate space communication relay systems for the near Earth domain. It indicates the sources of complexity in the modeling process, and discusses the validity and appropriateness of past approaches to the problem. In particular, it proposes a discussion of current models vis-à-vis the System Architecting Paradigm and how they fit into tradespace exploration studies. Next, the thesis introduces a computational performance model for the analysis and fast simulation of space relay satellite systems. The tool takes advantage of a specifically built-in rule-based expert system for storing the constitutive elements of the architecture and perform logical interactions between them. Analogously, it uses numerical models to assess the network topology over a given timeframe, perform physical layer computations and calculate plausible schedules for the overall system. In particular, it presents a newly developed heuristic scheduler that guarantees prioritization of specific missions and services while ensuring manageable computational times.[CASTELLÀ] El inicio de la carrera espacial se inició en 1957 con el lanzamiento y operación del primer satélite artificial, el Sputnik 1 de la URSS. Desde entonces se han desarrollado múltiples programas espaciales que han llevado al límite tanto la tecnología como la ciencia y han permitido desvelar los misterios del universo. En todos estos casos, la necesidad de sistemas de comunicación flexibles y fiables ha sido primordial con el fin de asegurar el retorno de los datos científicos recopilados y, en ciertos casos, garantizar la seguridad de los astronautas. Como consecuencia, múltiples redes de comunicaciones espaciales han sido desplegadas, ya sea a través de antenas globalmente distribuidas a través de la superficie terrestre o mediante satélites repetidores. Hasta ahora la mayoría de estos sistemas se ha basado en estándares tecnológicos maduros y testeados, los cuales se han adaptado con el fin de satisfacer las necesidades específicas de cada misión y cliente. Sin embargo, las tendencias actuales en el diseño de los nuevos programas espaciales indica que un cambio de paradigma es necesario: una red espacial a imagen de Internet permitiría incrementar la capacidad y fiabilidad de las comunicaciones interplanetarias y, a la vez, reducir dramáticamente sus costes. En este contexto, el paradigma de arquitectura de sistemas puede ser un buen punto de partida. Mediante la descomposición formal del sistema, puede ayudar a determinar las decisiones que tienen un impacto cabal en el diseño de la arquitectura así como identificar las áreas con tecnologías similares y de menor coste. Esta tesis presenta un marco teórico general para evaluar sistemas de comunicaciones espaciales para misiones que orbitan la Tierra. Adicionalmente, la tesis indica los principales orígenes de complejidad durante el modelado del sistema y presenta una discusión sobre la validez de anteriores estrategias para analizar el problema. En concreto, propone una comparación de anteriores modelos respecto el paradigma de arquitectura de sistemas y su grado de adecuación para evaluar y comprar arquitecturas. A continuación, la tesis introduce un modelo computacional para simular y evaluar el rendimiento de sistemas de repetidores por satélite. La herramienta utiliza un rule-based expert system específicamente diseñado con el fin de almacenar los principales elementos constitutivos de la arquitectura y comprender las interacciones lógicas entre ellos. Análogamente, el modelo usa métodos numéricos con el fin de calcular la evolución temporal de la topología de la red en un determinado intervalo de tiempo, así como su capa física y un posible programa de contactos. En concreto, presenta un nuevo scheduler heurístico que garantiza la correcta ordenación de las misiones y servicios a la vez que asegura un tiempo computacional aceptable.[CATALÀ] L'inici de la cursa espacial va iniciar-se l'any 1957 amb el llançament i operació del primer satèl·lit artificial, l'Sputnik 1 de la URSS. Des d'aleshores s'han dut a terme múltiples programes espacials que han portat al límit tant la tecnologia com la ciència i han permès desvelar els misteris de l'univers. En tots aquests casos, la necessitat de sistemes de comunicació flexibles i fiables ha sigut primordial per tal d'assegurar el retorn de les dades científiques recopilades i, en certs casos, garantir el benestar i seguretat dels astronautes. Com a conseqüència, múltiples xarxes de comunicacions espacials han sigut desplegades, ja sigui a través d'antenes globalment distribuïdes a través de la superfície terrestre o mitjançant satèl·lits repetidors. Fins ara la majoria d'aquests sistemes s'han basat en estàndards tecnològics madurs i testats, els quals s'han adaptat per tal de satisfer les necessitats específiques de cada missió i client. Això no obstant, les tendències actuals en el disseny dels nous programes espacials indica que un canvi de paradigma és necessari: una xarxa espacial a imatge d'Internet permetria incrementar la capacitat i fiabilitat de les comunicacions interplanetàries i, alhora, reduir dramàticament els seu costs. En aquest context, el paradigma d'arquitectura de sistemes pot ser un bon punt de partida. Mitjançant la descomposició formal del sistema, pot ajudar a determinar les decisions que tenen un impacte cabdal en el disseny de l'arquitectura així com permetre identificar àrees amb tecnologies similars i de menor cost. Aquesta tesi presenta un marc teòric general per avaluar sistemes de comunicacions espacials per missions orbitant la Terra. Addicionalment, la tesi indica els principals orígens de complexitat durant el modelatge del sistema i presenta una discussió sobre la validesa d'anteriors estratègies per analitzar el problema. En concret, proposa una comparació d'anteriors models respecte el paradigma d'arquitectura de sistemes i el seu grau d'adequació per avaluar i comparar arquitectures. A continuació, la tesi introdueix un model computacional per simular i avaluar el rendiment de sistemes de repetidors per satèl·lit. L'eina empra un rule-based expert system específicament dissenyat per tal d'emmagatzemar els principals elements constitutius de l'arquitectura i comprendre les interaccions lògiques entre ells. Anàlogament, el model utilitza mètodes numèrics per tal de calcular l'evolució temporal de la topologia de la xarxa en un determinat interval de temps, així com calcular la seva capa física i un possible programa de contactes. En concret, presenta un nou scheduler heurístic que garanteix la correcte ordenació de les missions i serveis tot assegurant un temps de computació acceptable
Programmes in transition - between closure and start. Review of programme developments: Winter-Summer 2007
The past six months have seen a shift in emphasis from the 2000-2006 to the 2007-2013 programmes. Programme managers and other implementing organisations have not only been negotiating draft programmes for 2007-2013 with European Commission staff, but have also been undertaking a range of tasks to prepare for implementing these programmes. A number of initiatives have also occurred at EU level, which direct policymakers’ attention forward to the EU budget review of 2008-2009 and beyond. In addition, ongoing efforts have been needed to ensure that the remaining funds under the 2000-2006 programmes are effectively absorbed, and that all technical preparations for programme closure are underway
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