954 resultados para closed chamber-GC


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The European HiPER project aims to demonstrate commercial viability of inertial fusion energy within the following two decades. This goal requires an extensive Research &Development program on materials for different applications (e.g., first wall, structural components and final optics). In this paper we will discuss our activities in the framework of HiPER to develop materials studies for the different areas of interest. The chamber first wall will have to withstand explosions of at least 100 MJ at a repetition rate of 5-10 Hz. If direct drive targets are used, a dry wall chamber operated in vacuum is preferable. In this situation the major threat for the wall stems from ions. For reasonably low chamber radius (5-10 m) new materials based on W and C are being investigated, e.g., engineered surfaces and nanostructured materials. Structural materials will be subject to high fluxes of neutrons leading to deleterious effects, such as, swelling. Low activation advanced steels as well as new nanostructured materials are being investigated. The final optics lenses will not survive the extreme ion irradiation pulses originated in the explosions. Therefore, mitigation strategies are being investigated. In addition, efforts are being carried out in understanding optimized conditions to minimize the loss of optical properties by neutron and gamma irradiation

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An infrared optical wireless system is presented, consisting on autonomous remote nodes communicating with a central node. The network is designed for telecommand/telemetry purposes, comprising a large number of nodes at a low data rate. Simultaneous access is granted by using CDMA techniques, and an appropriate selection of the code family can also keep power consumption to a minimum

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The main objective of ventilation systems in case of fire is the reduction of the possible consequences by achieving the best possible conditions for the evacuation of the users and the intervention of the emergency services. In the last years, the required quick response of the ventilation system, from normal to emergency mode, has been improved by the use of automatic and semi-automatic control systems, what reduces the response times through the support to the operators decision taking, and the use of pre-defined strategies. A further step consists on the use of closedloop algorithms, which takes into account not only the initial conditions but their development (air velocity, traffic situation, etc), optimizing the quality of the smoke control process

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The solutions studied were Plant Vitrification Solutions 1, 2 and 3: (PVS1: Uragami et al. 1989, Plant Cell Rep. 8, 418; PVS2: Sakai et al. 1990, Plant Cell Rep. 9, 30; PVS3: Nishizawa et al. 1993, Plant Sci. 91, 67). Cooling was performed using the calorimeter control (5, 10 and 20°C min-1), or for higher rates, by quenching the closed pan with PVS in LN, either naked (faster - 5580°C min-1) or introduced in cryovials (reduced rate 360°C min-1). Quenched pans were then transferred to the sample chamber, pre-cooled to -196°C. Glass transition temperature was observed by DSC with a TA 2920 instrument, upon warming pans with solution samples from -145°C to room temperature, at standard warming rate10°C min-1.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tritium breeding is an essential component of future fusion nuclear reactors. Nuclear fusion reactors require Kg quantities of tritium per year of operation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Neutronics and activation of the preliminary reacion chamber of HiPER reactor based in a SCLL blanket

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Structural Health Monitoring (SHM) requires integrated "all in one" electronic devices capable of performing analysis of structural integrity and on-board damage detection in aircraft?s structures. PAMELA III (Phased Array Monitoring for Enhanced Life Assessment, version III) SHM embedded system is an example of this device type. This equipment is capable of generating excitation signals to be applied to an array of integrated piezoelectric Phased Array (PhA) transducers stuck to aircraft structure, acquiring the response signals, and carrying out the advanced signal processing to obtain SHM maps. PAMELA III is connected with a host computer in order to receive the configuration parameters and sending the obtained SHM maps, alarms and so on. This host can communicate with PAMELA III through an Ethernet interface. To avoid the use of wires where necessary, it is possible to add Wi-Fi capabilities to PAMELA III, connecting a Wi-Fi node working as a bridge, and to establish a wireless communication between PAMELA III and the host. However, in a real aircraft scenario, several PAMELA III devices must work together inside closed structures. In this situation, it is not possible for all PAMELA III devices to establish a wireless communication directly with the host, due to the signal attenuation caused by the different obstacles of the aircraft structure. To provide communication among all PAMELA III devices and the host, a wireless mesh network (WMN) system has been implemented inside a closed aluminum wingbox. In a WMN, as long as a node is connected to at least one other node, it will have full connectivity to the entire network because each mesh node forwards packets to other nodes in the network as required. Mesh protocols automatically determine the best route through the network and can dynamically reconfigure the network if a link drops out. The advantages and disadvantages on the use of a wireless mesh network system inside closed aerospace structures are discussed.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Of the south of Spain, near the province of Cordova, in a tributary of the Guadalquivir River it has been constructed during the years 2004 to 2007 the reservoir called El Arenoso. El Arenoso reservoir that belongs to Environment Ministry is destined to downstream Guadalquivir’s water supply and the general regulation of the river. The dam is located on the same name river and it is next to the Montoro’s municipal district, 41 km northeast of Cordova. The main work consists on an embankment dam, with central clay core, and slates and greywacke shoulders. The core is covered downstream with a filter material and upstream with a transition material. The dimensions of the dam are 80 m high, 1.480 m long at its crest, and it has been needed more than 3 million m3 of materials, creating a waterproof barrier able to keep 160 hm3 as a useful reservoir. In the zone of the core is located the chamber of valves with a horizontal clearance of 10 m and a vertical clearance of 14,517 m. The present article exposes the most important characteristics of project and construction, of valves chamber of the Arenoso reservoir.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En esta tesis se investiga de forma experimental el transporte pasivo de magnitudes físicas en micro-sistemas con carácter de inmediata aplicación industrial, usando métodos innovadores para mejorar la eficiencia de los mismos optimizando parámetros críticos del diseño o encontrar nuevos destinos de posible aplicación. Parte de los resultados obtenidos en estos experimentos han sido publicados en revistas con un índice de impacto tal que pertenecen al primer cuarto del JCR. Primero de todo se ha analizado el efecto que produce en un intercambiador de calor basado en micro-canales el hecho de dejar un espacio entre canales y tapa superior para la interconexión de los mismos. Esto genera efectos tridimensionales que mejoran la exracción de calor del intercambiador y reducen la caída de presión que aparece por el transcurso del fluido a través de los micro-canales, lo que tiene un gran impacto en la potencia que ha de suministrar la bomba de refrigerante. Se ha analizado también la mejora producida en términos de calor disipado de un micro-procesador refrigerado con un ampliamente usado plato de aletas al implementar en éste una cámara de vapor que almacena un fluido bifásico. Se ha desarrollado de forma paralela un modelo numérico para optimizar las nuevas dimensiones del plato de aletas modificado compatibles con una serie de requerimientos de diseño en el que tanto las dimensiones como el peso juegan un papel esencial. Por otro lado, se han estudiado los fenomenos fluido-dinámicos que aparecen aguas abajo de un cuerpo romo en el seno de un fluido fluyendo por un canal con una alta relación de bloqueo. Los resultados de este estudio confirman, de forma experimental, la existencia de un régimen intermedio, caracterizado por el desarrollo de una burbuja de recirculación oscilante entre los regímenes, bien diferenciados, de burbuja de recirculación estacionaria y calle de torbellinos de Karman, como función del número de Reynolds del flujo incidente. Para la obtención, análisis y post-proceso de los datos, se ha contado con la ayuda de un sistema de Velocimetría por Imágenes de Partículas (PIV). Finalmente y como adición a este último punto, se ha estudiado las vibraciones de un cuerpo romo producidas por el desprendimiento de torbellinos en un canal de alta relación de bloqueo con la base obtenida del estudio anterior. El prisma se mueve con un movimiento armónico simple para un intervalo de números de Reynolds y este movimiento se transforma en vibración alrededor de su eje a partir de un ciero número de Reynolds. En relación al fluido, el régimen de desprendimiento de torbellinos se alcanza a menores números de Reynolds que en el caso de tener el cuerpo romo fijo. Uniendo estos dos registros de movimientos y variando la relación de masas entre prisma y fluido se obtiene un mapa con diferentes estados globales del sistema. Esto no solo tiene aplicación como método para promover el mezclado sino también como método para obtener energía a partir del movimiento del cuerpo en el seno del fluido. Abstract In this thesis, experimental research focused on passive scalar transport is performed in micro-systems with marked sense of industrial application, using innovative methods in order to obtain better performances optimizing critical design parameters or finding new utilities. Part of the results obtained in these experiments have been published into high impact factor journals belonged to the first quarter of the Journal Citation Reports (JCR). First of all the effect of tip clearance in a micro-channel based heat sink is analyzed. Leaving a gap between channels and top cover, letting the channels communicate each other causes three-dimensional effects which improve the heat transfer between fluid and heat sink and also reducing the pressure drop caused by the fluid passing through the micro-channels which has a great impact on the total cooling pumping power needed. It is also analyzed the enhancement produced in terms of dissipated heat in a micro-processor cooling system by improving the predominantly used fin plate with a vapour chamber based heat spreader which contains a two-phase fluid inside. It has also been developed at the same time a numerical model to optimize the new fin plate dimensions compatible with a series of design requirements in which both size and wight plays a very restrictive role. On the other hand, fluid-dynamics phenomena that appears downstream of a bluff body in the bosom of a fluid flow with high blockage ratio has been studied. This research experimentally confirms the existence of an intermediate regime characterized by an oscillating closed recirculation bubble intermediate regime between the steady closed recirculation bubble regime and the vortex shedding regime (Karman street like regime) as a function of the incoming flow Reynolds number. A particle image velocimetry technique (PIV) has been used in order to obtain, analyze and post-process the fluid-dynamic data. Finally and as an addition to the last point, a study on the vortexinduced vibrations (VIV) of a bluff body inside a high blockage ratio channel has been carried out taking advantage of the results obtained with the fixed square prism. The prism moves with simple harmonic motion for a Reynolds number interval and this movement becomes vibrational around its axial axis after overcoming at definite Reynolds number. Regarding the fluid, vortex shedding regime is reached at Reynolds numbers lower than the previous critical ones. Merging both movement spectra and varying the square prism to fluid mass ratio, a map with different global states is reached. This is not only applicable as a mixing enhancement technique but as an energy harvesting method.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

El barrio de Chamberí, situado la norte del casco histórico de Madrid, fue en su origen un arrabal exterior al recinto cercado de la Villa. Se ubicó sobre una infraestructura viaria previa formada por la carretera de Francia, cuyo trazado había sido regularizado a principios del s XIX, y los paseos arbolados creados treinta años después. La Administración intentó controlar el incipiente núcleo de población surgido de forma espontánea. Los Arquitectos Municipales levantaron un plano del estado del lugar, redactaron unas escuetas reglas de construcción y dibujaron sucesivos planos de alineaciones en los que se prefiguraba la ciudad. Pero el traslado de la ciudad planeada al terreno dependía de la iniciativa de los propietarios del suelo y el proceso fue lento y difícil. Al finalizar el cuarto de siglo que discurrió entre 1833 y 1858, en que Chamberí fue un arrabal independiente al margen de la Villa, el tejido urbano consolidado era discontinuo y desigual. La puesta en marcha del Ensanche de Madrid marcó un cambio de rumbo. Los terrenos ocupados por el arrabal entraron a formar parte de él. Se proyectó una nueva ordenación para el barrio en relación con el conjunto del Ensanche que alteraba el planeamiento vigente. Las protestas de los propietarios de Chamberí, que veían como sus casas podían llegar a ser arrasadas, influyeron de forma decisiva, entre otras cuestiones, en el desmantelamiento del Plan Castro. Las trazas del arrabal planeadas a mediados del siglo XIX que se habían materializado en el terreno permanecen en la ciudad actual. En esta investigación se ha analizado la forma urbana del barrio y su evolución en el tiempo, intentando descifrar sus causas. Se describe el territorio donde se ubicó Chamberí, los asentamientos existentes y los elementos que limitaron su extensión: la ciudad cercada por el sur, los cuatro cementerios que jalonaban la antigua carretera de Francia por poniente y la vaguada de la Castellana por el este. Se compara el crecimiento del tejido urbano en la realidad con los proyectos de ordenación realizados para el arrabal. También se han estudiado las arquitecturas no construidas y los proyectos de ciudad no realizados. Estas ideas, que solo fueron líneas y manchas en el papel, nos permiten imaginar como pudo haber sido el barrio si la historia hubiera seguido otros caminos posibles. En la búsqueda de esas ciudades perdidas, tanto las que existieron como las tan solo pensadas, se ha utilizado el dibujo como medio irrefutable de proyectar el pasado y expresar su forma. Se ha realizado una secuencia cronológica de 22 planimetrías que muestra la transformación de Chamberí y su entorno, y los proyectos realizados para ese territorio con idénticos criterios -misma escala y recursos gráficos similares- que se encuentran en las primeras páginas del tomo II de este documento. La narración gráfica del proceso evolutivo se concluye con un plano a mayor escala, subdividido en cuatro cuadrantes, en el que se superponen sobre el parcelario actual varios de los momentos para evidenciar las permanencias y mutaciones. Así mismo, el discurso general es gráfico y literal; las palabras se complementan con las imágenes existentes sobre las cuestiones tratadas y con los dibujos elaborados que las reconstituyen.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The HiPER reactor design is exploring different reaction chambers. In this study, we tackle the neutronicsand activation studies of a preliminary reaction chamber based in the following technologies: unpro-tected dry wall for the First Wall, self-cooled lead lithium blanket, and independent low activation steelVacuum Vessel. The most critical free parameter in this stage is the blanket thickness, as a function ofthe6Li enrichment. After a parametric study, we select for study both a ?thin? and ?thick? blanket, with?high? and ?low?6Li enrichment respectively, to reach a TBR = 1.1. To help to make a choice, we com-pute, for both blanket options, in addition to the TBR, the energy amplification factor, the tritium partialpressure, the203Hg and210Po total activity in the LiPb loop, and the Vacuum Vessel thickness requiredto guarantee the reweldability during its lifetime. The thin blanket shows a superior performance in thesafety related issues and structural viability, but it operates at higher6Li enrichment. It is selected forfurther improvements. The Vacuum Vessel shows to be unviable in both cases, with the thickness varyingbetween 39 and 52 cm. Further chamber modifications, such as the introduction of a neutron reflector,are required to exploit the benefits of the thin blanket with a reasonable Vacuum Vessel.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper describes the new anechoic chamber available at The University of Kent, UK. This facility includes a spherical near/far field, planar near field, cylindrical near field and a compact range. The facility allows measurement from 600 MHz up to 110 MHz. The spherical, planar and cylindrical ranges covers up to 40 GHz and the compact range is available from 50 GHz up to 110 MHz. Immediate plans are to use the new facility to measure body-centric antennas and sensing nodes together with near field sampling of finite sized Frequency Selective Surfaces.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

En este trabajo se han identificado los deslizamientos y desprendimientos que se pueden desarrollar en el acantilado de El Rincón (Gran Canaria) y sus repercusiones sobre la Autovía GC-2, en la base del acantilado. El análisis de estabilidad realizado para las condiciones actuales indica que la ladera es estable. El análisis a largo plazo considera el sustrato saturado en agua y se limita a los dos bloques rocosos más susceptibles de experimentar deslizamiento: uno a media ladera y otro en coronación. El deslizamiento del bloque de coronación parece más probable ya que sólo requiere la saturación de los piroclastos y está favorecido por la progresiva apertura de la grieta subvertical. Por último, la evaluación de los desprendimientos rocosos que afectan al acantilado indica que los bloques no alcanzarían la calzada de la autovía GC-2; sino que se acumularían en los conos de deyección presentes al pie de la ladera.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This paper includes the experimental study, analysis, redesign and subsequent test of the parts of a closed circuit, low speed wind tunnel which are relevant in terms of total pressure loss. The objective is to lower the energy consumption of this system for given conditions in test chamber, so as to reduce the operational costs. In order to achieve this objective, several tasks were performed as the text shows in its different parts. For these tasks, the ETSIAE wind tunnel was used, although the results of this work can be extrapolated to any wind tunnel with the same characteristics. Part II presents a theoretical previous study of the general running of a closed circuit, low speed wind tunnel, as well as the followed procedure to conduct experimental tests for obtaining the total pressure loss in its parts. Results from these tests and their analysis are included in this part. In part III, the analysis of the influence of corner 1 on the pressure loss takes place. As it is said in this part, corner 1 has great importance in the total pressure loss of the wind tunnel. Therefore, it is the first part that should be modified in order to improve the performances of the wind tunnel. During part IV, an optimised guide vane is designed in order to reduce the pressure loss in corner 1 of the wind tunnel. Software MISES is used to achieve this goal by means of selecting the optimum guide vane. In order to introduce the new guide vane in wind tunnels with affordable costs, the easily constructable criterion is kept during design. For this reason, the guide vane will consist of simple aerodynamic contours. Part V includes some possible improvements for the proposed guide vane, in order to evaluate if there is room for improvement in its design. Finally, part VI includes the tests that were conducted in the wind tunnel with the new guide vane cascade and the analysis of their results, in order to asses whether the proposed design fulfills the requirement of lowering the total pressure loss in the wind tunnel. Part VII gathers the main ideas resulting from the whole work.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Fundación Ciudad de la Energía (CIUDEN) is carrying out a project of geological storage of CO2, where CO2 injection tests are planned in saline aquifers at a depth of 1500 m for scientific objectives and project demonstration. Before any CO2 is stored, it is necessary to determine the baseline flux of CO2 in order to detect potential leakage during injection and post-injection monitoring. In November 2009 diffuse flux measurements of CO2 using an accumulation chamber were made in the area selected by CIUDEN for geological storage, located in Hontomin province of Burgos (Spain). This paper presents the tests carried out in order to establish the optimum sampling methodology and the geostatistical analyses performed to determine the range, with which future field campaigns will be planned.