A Full Fingerprint Verification System for a Single-Line Sweep Sensor

This paper presents a full fingerprint verification system. It is composed of a tactile fingerprint sensor, integrated read out and conversion circuits, and dedicated recognition algorithms. The sensor is a single-line sweep mode sensor, e.g., it is made of a single line of sensing elements, thus covering the minimum surface of silicon. Compared with cm² sized touch sensors, it offers a large cost reduction and possibility of easy integration into portable devices. The use of a single line to measure a fingerprint requires the user to sweep its finger along the sensor. This sensing scheme produces fingerprint images with several distortions that needs further image processing to allow efficient fingerprint recognition. This is why we developed and present here specific algorithms to take care of the sensor's specifications. This paper will present measurement results, as well as a performance evaluation of the entire verification system.     

Thermal Monitoring of Self-Checking Systems

With the increasing power density in integrated systems resulting from scaling down, the occurrence of field failures due to overheating has considerably increased. Faulty operation can be prevented by on-line temperature monitoring. This paper deals with questions of on-line temperature monitoring in safety-critical systems. First the possible temperature sensors are reviewed and basic principles of self-checking systems including such sensors are detailed, then a new temperature sensor cell with extremely good parameters designed especially for DfTT applications is presented. The basic questions of integrating thermal sensors into self-checking systems are also discussed.     

Mechanical simulations of SANDIA II tests OECD ISP 48 benchmark

This paper illustrates the work carried out by EDF within the framework of ISP 48 post-test analysis of NUPEC/NRC 1:4-scale model of a prestressed pressure containment vessel of a nuclear power plant [Hessheimer, M.F., Klamerus, E.W., Rightly, G.S., Lambert, L.D., Dameron, R.A., 2003. Overpressurization test of a 1:4-scale prestressed concrete containment vessel model. NUREG/CR-6810, SAND2003-0840P. Sandia National Laboratories, Albuquerque, NM]. EDF as a participant of the International Standard Problem no. 48 [Mathet, E., Hessheimer, M., Ali, S., Tegeler, B., 2005. An international standard problem: analysis of 1:4-scale prestressed concrete containment vessel model under severe accident conditions. Proceedings of 18th International Conference on Structural Mechanics in Reactor Technology. SMiRT 18. Beijing, China] has participated in this program, within the framework of its research and development program on the simulation of non-linear behaviour of nuclear power plant prestressed concrete pressure containment vessels. EDF performed several simulations to determine the ultimate response of the scale model. To determine the most influent parameters in such an analysis several studies were carried out. A full 3D mesh of the entire structure was then created. The mesh was built using a parametric tool to measure the influence of discretization on results. To represent the cracking of concrete, two material laws were then used. The purpose of this paper is to illustrate the ultimate behaviour of SANDIA II model obtained by Code_Aster^® finite element platform, with comparison to tests records, and also to share the lessons learned from the parametric computations and underline precautions that must be taken in such studies.     

Catalytic wall reactor: Catalytic coatings of stainless steel by VOx/TiO2 and Co/SiO2 catalysts

Catalytic wall (structured) reactors and structured supports are suitable to study the catalytic properties of nanosized materials. The coating of metallic (aluminum and stainless steel) plates by thin layers of active phase is presented in two cases, VO_x/TiO₂ and Co/SiO₂, catalysts used in the oxidative dehydrogenation (ODH) of propane and in Fischer–Tropsch synthesis (FTS) of clean fuels, respectively. The preparation of coated plates and their characterisation by various methods of physicochemical analysis are described. Both chemical and physical methods were used for coating. VO_x/TiO₂ layers were obtained by grafting of Ti (on Al or stainless-steel plates) and V (on TiO₂) alkoxides and use of sol–gel media or suspension. A silica primer was deposited (on stainless-steel plate) by plasma-assisted chemical vapour deposition (PACVD) onto which Co oxide and silica were coprecipitated from sol–gel. The catalytic experiments in the respective reactions were carried out in special plate reactors and compared with those of catalytic powders. The study shows that the coating of a metallic substrate by a catalyst is not straightforward and requires specific studies dealing with both chemistry (chemical affinity between substrate and catalytic layers) and catalytic engineering (catalytic performance in taylor-made reactors).     

Characterisation by TPR, XRD and NOx Storage Capacity Measurements of the Ageing by Thermal Treatment and SO2 Poisoning of a Pt/Ba/Al NOx-Trap Model Catalyst

The deactivation of a Pt/Ba/Al₂O₃ NO _x -trap model catalyst submitted to SO₂ treatment and/or thermal ageing at 800 °C was studied by H₂ temperature programmed reduction (TPR), X-ray diffraction (XRD) and NO _x storage capacity measurements.The X-ray diffractogram of the fresh sample exhibits peaks characteristic for barium carbonate. Thermal ageing leads to the decomposition of barium carbonate and to the formation of BaAl₂O₄. The TPR profile of the sulphated sample shows the presence of (i) surface aluminium sulphates, (ii) surface barium sulphates, (iii) bulk barium sulphates. The exposure to SO₂ after ageing leads to a small decrease of the surface barium-based sulphates, expected mainly as aluminate barium sulphates. This evolution can be attributed to a sintering of the storage material. TPR experiments also show that thermal treatment at 800 °C after the exposure to SO₂ involves the decomposition of aluminium surface sulphates to give mainly bulk barium sulphates, also pointed out by XRD. Thus, the thermal treatment at 800 °C leads to a stabilization of the sulphates.These results are in accordance with the NO _x storage capacity measurements. On non-sulphated catalysts, the treatment at 800 °C induces to a decrease of the NO _x storage capacity, showing that barium aluminate presents a lower NO _x storage capacity than barium carbonate. Sulphation strongly decreases the NO _x storage capacity of catalysts, whatever the initial thermal treatment, showing that barium sulphates inhibit the NO₂ adsorption. Moreover, the platinum activity for the NO to NO₂ oxidation is lowered by thermal treatments.