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.     

A sweeping mode integrated fingerprint sensor with 256 tactile microbeams

This paper reports recent advances in the development of a tactile fingerprint sensor made by a CMOS compatible front side bulk micromachining technology. This device enables the measurement of a fingerprint by the way of a mechanical scanning principle of the finger roughness. While this sensing principle has shown good results on a first prototype of reduced width, we present here the design, fabrication and test of a new sensor. This sensor contains 256 pressure sensitive microbeams for a total length of 1.28 cm and is fully integrated with analog and mixed signal electronics. In this paper we will detail the general working principle of the tactile fingerprint sensor and the two prototypes that have been manufactured and tested with a special focus on the electronic architecture and the test results of the second prototype.     

High-level expression of a novel epitope of CD59 identifies a subset of CD34+ bone marrow cells highly enriched for pluripotent stem cells

To further define the hierarchy of human hematopoietic progenitor cells, we have attempted to identify antibodies to cell-surface molecules expressed on CD34+ progenitor cell subsets. Herein we describe the utility of a new monoclonal antibody, HCC-1, which binds to a novel epitope of CD59 differentially expressed among CD34+ progenitor cells. HCC-1 subdivides the adult marrow CD34+ population into HCC-1high and HCC-1low/- fractions of approximately equal size. Cobblestone area-forming cells (CAFC) in long-term bone marrow culture were enriched 10-30-fold in CD34+HCC-1high cells compared with CD34+HCC1-low/- cells and two-fold compared with CD34+ cells. When injected into fetal human bone fragments implanted in SCID mice, the CD34+HCC-1high population showed potent engrafting activity leading to the production of myeloid, lymphoid, and erythroid elements, as well as the retention of progenitor cell phenotype. These studies demonstrate that the CD34+HCC-1high population contains primitive pluripotent hematopoietic stem cells. No hematopoietic engrafting activity was detected in the CD34+HCC-1low/- population. Consistent with this finding, simultaneous five-color flow cytometric analysis revealed that HCC-1high cells include virtually all CD34+Thy-1+Lin- cells, a cell population previously characterized as highly enriched for primitive pluripotent hematopoietic stem cells. The ability of CD34+ cells divided into subsets by HCC-1 to produce T cells was assessed by transplantation of sorted cells into human fetal thymus implanted into SCID mice. A higher frequency of thymus-engrafting activity was observed in the CD34+HCC-1high than in the CD34+HCC-1low/- population. Consistent with the limited ability to engraft in the SCID-hu thymus model, the CD34+HCC-1low/- population was shown to contain a low frequency of CD34+CD10+ lymphoid progenitor cells. We conclude that the HCC-1 epitope is expressed at high levels on a subset of CD34+ cells that contain virtually all primitive pluripotent hematopoietic stem cells and that the population of CD59 molecules expressed on CD34+ cells is not homogeneous.     

Two ways of synthesis of polymer networks based on diglycidyl ether of bisphenol A,bisphenol A,and sulfanilamide: Kinetics study

The kinetics of reactions of ternary systems based on bisphenol A diglycidyl ether, bisphenol A, and a sulfanilamide curing agent were investigated using HPLC, during two different synthesis paths. The influence of tetrabutylphosphonium tetrafluoroborate as a catalyst for the epoxy–phenol reaction was studied. For the same initial composition, polymers differing by the crosslink point distribution and the chain length between crosslinks were synthesized. Different solid‐state behavior is expected in these two categories of networks. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 580–591, 2001     

Effects of crosslink density on mechanical properties of high glass transition temperature polycyanurate networks

Polycyanurate networks of different architecture were synthesized using different curing cycles. Networks with a variable extent of reaction were obtained; the small variation of the cyanate conversion (0.8 to 1) corresponds to a large variation of glass transition temperature (150–290°C) and crosslink density. The mechanical behavior at small and large deformations and the fracture toughness were examined at room temperature and related to the network structural parameters. To explain the puzzling variation of the yield stress and yield strain with the cyanate conversion, recovery experiments were conducted to discriminate anelastic deformation from plastic deformation. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2471–2479, 1997     

Spark Plasma synthesis and diffusion of Cu and Ag in vanadium mixed valence oxides

Spark Plasma sintering (SPS) technique allows powders to be compacted at low temperature with a very short holding time. The powder loaded into a carbon die is heated via direct current pulses and simultaneously submitted to an uni-axial pressure of several MPa. Full density of the sample is achieved within minutes. This process is used to study Cu and Ag metals interactions with V₂O₅ oxide. Syntheses of M _x V₂O₅ phases (M = Cu, Ag) have been achieved within minutes. Thus Cu and Ag atoms penetrate microcrystals of V₂O₅ oxide at a high speed, shearing its crystal network and simultaneously rebuilding the crystal structures of the prototype networks β, β′, ε or δ M _x V₂O₅. To account for the formation of these phases identified by X-ray diffraction, structural mechanisms are proposed. Cu and Ag atomic diffusion parameters have been determined from energy dispersive X-ray spectroscopy (EDX) and electron micropobe analysis (EPMA) line scans. High values of diffusion coefficients have been determined. Cu atoms diffuse faster than Ag, D _Cu ≈ 4 × 10⁻⁸ m²/s and D _Ag ≈ 0.5–1 × 10⁻⁹ m²/s in ε and δ M _x V₂O₅ phases, respectively. Their formation may also be used as a model for further investigations into the diffusion mechanisms of atoms in solids and for a better understanding of the SPS process.

---

Molecular modelling of polyphthalamides thermal properties: Comparison between modelling and experimental results

The aim of this study was to investigate new polyphthalamides (PPA) through the use of molecular modelling techniques and comparison with experimental data. The objectives were to provide a computer simulation method that can be used to predict the properties of polyphthalamides with a good reliability with respect to the experimentally synthesized materials. Several PPA with a variable amount of aromatic units derived from condensation with hexamethylene diamine (HMDA) and terephthalic acid (TPA) or isophthalic acid (IPA) were synthesized. These polymers were characterized using thermal analysis, size-exclusion chromatography, NMR and viscosimetry techniques. The same PPA were modelled at the atomistic level and molecular dynamics simulations were run. The glass transition temperature (T_g) of the various materials was used to make comparisons between simulations and experiments. The results were found to be in good agreement and the simulation method can be used to predict thermal properties of this class of polyamides.     

Intrapericardial fibrinolysis: a useful treatment in the management of purulent pericarditis

Since the introduction of antibiotics into clinical practice, purulent pericarditis has become a rare disease. The major complication of the standard management for this condition is constrictive pericarditis. We report two cases of purulent pericarditis in which intrapericardial fibrinolysis was performed in order to minimize this complication. The first case was a 38-year-old man admitted to our intensive care unit (ICU) for management of constrictive pericarditis complicating purulent pericarditis diagnosed 17 days previously. The patient was treated with four intrapericardial injections of streptokinase (250,000 IU each). Fluid drainage and cardiac output were improved. No change in clotting parameters was noted. Pericardiectomy and esophagectomy were then performed for a diagnosis of esophageal neoplasm. The postoperative course was uneventful. The second case was a 16-year-old boy admitted with loss of consciousness due to cardiac tamponade. Percutaneous pericardiocentesis drained 900 ml of cloudy fluid. Two intrapericardial injections were performed (day 1 and day 5) without any complication. Pericardial drainage was withdrawn on day 13 and the patient was discharged from ICU on the same day. Six months later, there was no evidence of constrictive pericarditis. Intrapericardial fibrinolysis appears to be safe and effective when prescribed rapidly in the course of purulent pericarditis.