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Ekberg J.-E.,Advanced Development | Kostiainen K.,ETH Zurich | Asokan N.,University of Helsinki
IEEE Security and Privacy

Hardware-based trusted execution environments (TEEs) have been available in mobile devices for more than a decade, but their use has been limited. The On-board Credential system safely opens up TEEs so application developers can use their functionality to improve security and usability. © 2014 IEEE. Source

Chalet D.,Ecole Centrale Nantes | Mahe A.,Ecole Centrale Nantes | Migaud J.,Advanced Development | Hetet J.-F.,Ecole Centrale Nantes
Applied Energy

The simulation of pressure waves in inlet and exhaust manifolds of internal combustion engines remains challenging. In this paper, a new model is presented in order to analyze these pressures waves without the use of a one-dimensional description of the system. It consists on studying the system using a frequency approach. In order to establish this model, a dynamic flow bench is used. The latter has been modified in order to generate waves in a gas which can be in motion or not. The inlet system is then characterized by its geometrical characteristics as well as the fluid characteristics. Indeed, the gas temperature and the gas velocity have a major impact on the fluid behaviour. The new model is then used in order to simulate the pressure waves into a 1-m pipe which is connected to a driven engine acting as a pulse generator. The experimental and the numerical results are in good agreement. © 2011 Elsevier Ltd. Source

Chalet D.,Ecole Centrale Nantes | Mahe A.,Ecole Centrale Nantes | Hetet J.-F.,Ecole Centrale Nantes | Migaud J.,Advanced Development
Journal of Thermal Science

This paper presents a new model used to describe the propagation of pressure waves at the inlet systems of internal combustion engine. In the first part, an analogy is made between the compressible air in a pipe and a mechanical ideal mass damper spring system. A new model is then presented and the parameters of this model are determined by the use of an experimental setup (shock tube test bench). With this model, a transfer function is defined in order to link directly the pressure and the air mass flow rate. In the second part, the model is included into an internal combustion engine simulation code. The results obtained with this code are compared to experimental ones which are measured on a one-cylinder engine test bench. This last one is driven by an electric motor in order to study only the effect of the pressure waves on the engine behavior. A good agreement is obtained between the experimental results and the numerical ones and the new approach is an alternative method for modeling the pressure wave phenomena in an internal combustion engine manifold. © Science Press and Institute of Engineering Thermophysics, CAS and Springer-Verlag Berlin Heidelberg 2010. Source

Van Gastel S.,Advanced Development
SMT Surface Mount Technology Magazine

Assemblers currently looking to upgrade their production lines need to look not only at today's equipment requirements, but those of their next equipment generations. What will mobile phones, computers and other equipment look like in five years? The answer to this question will determine future assembly requirements. Source

Strohm G.S.,Purdue University | Son S.F.,Purdue University | Boucher C.J.,Advanced Development
48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition

The move from conventional energetic composites to nanoscale energetic mixtures (nanoenergetics) has shown dramatic improvement in energy release rate and sensitivity to ignition. A possible application of nanoenergetics is on a semiconductor bridge (SCB). An SCB typically requires a tenth of the energy input as compared to a bridge wire design with the same no-fire and is capable of igniting in tens of microseconds. For very low energy applications SCBs can be manufactured to extremely small sizes and it is necessary to find materials with particle sizes that are even smaller to function, since reactive particles of comparable size to the bridge can lead to problems with ignition reliability for small bridges. Nanoenergetic composites and the use of SCBs have been significantly studied individually, however, the process of combining nanoenergetics with an SCB has not been investigated extensively and is the focus of this paper. Goals of this study are to determine if nanoenergetics can be used with SCBs to further reduce the minimum energy required and improve reliability. The performance of nanoscale aluminum (nAl) and bismuth oxide (Bi2O3) with nitrocellulose (NC), Fluorel™ FC 2175 (chemically equivalent to Viton®) and the Glycidyl Azide Polymer (GAP) as binders was quantified using the Neyer algorithm at three weight fractions (5, 7, and 9%) of binder. The threshold energy was also calculated and compared to previous data using conventional materials such as zirconium potassium chlorate (ZPC), mercuric 5-Nitrotetrazol (DXN-1) and titanium sub-hydride potassium perchlorate (TSPP). It was found that even though there was negligible difference in performance between the binders with nAl/Bi2O 3 at any of the three binder weight fractions, the results show that these nanoenergetic materials require about half of the threshold energy compared to conventional materials using an SCB with an 84×42 μm bridge. A 36×15 μm bridge size was also tested using the 9% GAP nAl/Bi2O3 slurry, creating a functioning SCB compared to previous no ignition results using TSPP. These are initial results and further testing is required for full characterization and no optimization has been pursued yet. © 2010 by the American Institute of Aeronautics and Astronautics, Inc. Source

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