941 resultados para Full-thickness burns
Resumo:
Interfacial waves on the surface of a falling liquid film are known to modify heat and mass transfer. Under non-isothermal conditions, the wave topology is strongly influenced by the presence of thermocapillary (Marangoni) forces at the interface which leads to a destabilization of the film flow and potentially to critical film thinning. In this context, the present study investigates the evolution of the surface topology and the evolution of the surface temperature for the case of regularly excited solitary-type waves on a falling liquid film under the influence of a wall-side heat flux. Combining film thickness (chromatic confocal imaging) and surface temperature information (infrared thermography), interactions between hydrodynamics and thermocapillary forces are revealed. These include the formation of rivulets, film thinning and wave number doubling in spanwise direction. Distinct thermal structures on the films’ surface can be associated to characteristics of the surface topology.
Resumo:
This paper describes how modeling technology has been used in providing fatigue life time data of two flip-chip models. Full-scale three-dimensional modeling of flip-chips under cyclic thermal loading has been combined with solder joint stand-off height prediction to analyze the stress and strain conditions in the two models. The Coffin-Manson empirical relationship is employed to predict the fatigue life times of the solder interconnects. In order to help designers in selecting the underfill material and the printed circuit board, the Young's modulus and the coefficient of thermal expansion of the underfill, as well as the thickness of the printed circuit boards are treated as variable parameters. Fatigue life times are therefore calculated over a range of these material and geometry parameters. In this paper we will also describe how the use of micro-via technology may affect fatigue life
Resumo:
A toxicity model on dividing the computational domain into two parts, a control region (CR) and a transport region (TR), for species calculation was recently developed. The model can be incorporated with either the heat source approach or the eddy dissipation model (EDM). The work described in this paper is a further application of the toxicity model with modifications of the EDM for vitiated fires. In the modified EDM, chemical reaction only occurs within the CR. This is consistent with the approach used in the species concentration calculations within the toxicity model in which yields of combustion products only change within the CR. A vitiated large room-corridor fire, in which the carbon monoxide (CM) concentrations are very high and the temperatures are relatively low at locations distant from the original fire source, is simulated using the modified EDM coupled with the toxicity model. Compared with the EDM, the modified EDM provide significant improvements in the predictions of temperatures at remote locations. Predictions of species concentrations at various locations follow the measured trends. Good agreements between the measured and predicted species concentrations are obtained at the vitiated fire stage.
Resumo:
The electric current and the associated magnetic field in aluminium electrolysis cells create effects limiting the cell productivity and possibly cause instabilities: surface waving, ‘anode effects’, erosion of pot lining, feed material sedimentation, etc. The instructive analysis is presented via a step by step inclusion of different physical coupling factors affecting the magnetic field, electric current, velocity and wave development in the electrolysis cells. The full time dependent model couples the nonlinear turbulent fluid dynamics and the extended electromagnetic field in the cell, and the whole bus bar circuit with the ferromagnetic effects. Animated examples for the high amperage cells are presented. The theory and numerical model of the electrolysis cell is extended to the cases of variable cell bottom of aluminium layer and the variable thickness of the electrolyte due to the anode non-uniform burn-out process and the presence of the anode channels. The problem of the channel importance is well known Moreau-Evans model) for the stationary interface and the velocity field, and was validated against measurements in commercial cells, particularly with the recently published ‘benchmark’ test for the MHD models of aluminium cells [1]. The presence of electrolyte channels requires also to reconsider the previous magnetohydrodynamic instability theories and the dynamic wave development models. The results indicate the importance of a ‘sloshing’ parametrically excited MHD wave development in the aluminium production cells.
Resumo:
This deliverable outlines the design blueprints for the RAGE application scenario games and forms the rest of the scope for WP4’s tasks. The game designs have been developed in collaboration with application scenario partners in WP5, and informed by WP1, 2 & 3. Additionally peer-feedback has been provided by game developers across WP4. The designs outline the integration of the RAGE assets developed in WP2 and WP3. Each section provides in detail the game play descriptions, game dynamics and mechanics, pedagogies and technical implementation of the RAGE assets into the game applications as described in detailed in WP5’s application documents. The full description of the application objectives and associated learning outcomes has been provided in the project’s MS2 Application Scenario Outlines document.
Resumo:
El presente estudio tiene el objetivo de ofrecer una visión general sobre los Modelos de Desarrollo y Organización Territorial desde la perspectiva de las relaciones entre el medio urbano, “rururbano” y rural, en España. Para ello, tras conocer y valorar los enfoque conceptuales y temáticos, se estudia el crecimiento urbano en nuestro país en las últimas décadas, analizando de manera pormenorizada la importancia que ha cobrado y cobra la aplicación legislativa de leyes, planes y normas, tanto en el propio crecimiento urbano como en la demanda de viviendas en las ciudades españolas y, de igual modo, la vinculación de ambas con el precio de las viviendas, relacionándolo con la problemática de la “rururbanización”, y del medio rural.