Morphological and physicochemical properties of dip-coated poly {(2,5-diyl pyrrole) [4-nitrobenzylidène]} (PPNB) thin films: towards photovoltaic applications

A new material: conjugated poly {(2,5-diyl pyrrole) [4-nitrobenzylidène]}, that we called (PPNB), has been synthesized and characterized. The cyclic voltammetry has been used in order to estimate first oxidation (Ep) and reduction (En) potentials of our polymer. These values have been assigned, respectively, to the position of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) and determination of the energy band gap which have been estimated to be 6.16, 3.89 and 2.27 eV respectively. Energy levels values of the HOMO and LUMO of the PPNB polymeric donor material were evaluated and the results are compatible with an electron transfer to C60 within an eventual junction, such values show that PPNB could be probed for applications in organic solar cells as donor material. PPNB Thin films have been deposited by dip-coating technique from Dichloromethane solvent with different polymer concentrations, and a dipping speed of 3.0 cm/min. For morphological characterization of the films scanning electron microscopy (SEM) was carried out. The samples, when observed by SEM, reveals that the films deposited are less dense, uniform. Cross-sectional SEM micrographs PPNB films show that thickness of the layers is homogeneous and has value of 35–40 nm. Optical characteristics of the polymer thin films were studied using UV-vis spectroscopy; absorption of wide range of wavelengths from 350 to 700 nm was observed. The optical band gap energy ranges between 1.9 eV and 1.94 eV. Based on these analyzes we realized heterojunction organic solar cells with the structure: ITO/Au/PPNB/C60/BCP/Al, the cells had a photovoltaique effect after J-V measuring, however the efficiency of photo generation under AM1.5 illumination was weak (about 0.02%) and needs to be improved

Association of Spermatogenic Failure with the b2/b3 Partial AZFc Deletion

Infertility affects around 1 in 10 men and in most cases the cause is unknown. The Y chromosome plays an important role in spermatogenesis and specific deletions of this chromosome, the AZF deletions, are associated with spermatogenic failure. Recently partial AZF deletions have been described but their association with spermatogenic failure is unclear. Here we screened a total of 339 men with idiopathic spermatogenic failure, and 256 normozoospermic ancestry-matched men for chromosome microdeletions including AZFa, AZFb, AZFc, and the AZFc partial deletions (gr/gr, b1/b3 and b2/b3)

Effect of shielded electrodes dimensions on corona charging systems

International audienceDual-type corona electrodes, consisting of a thin ionizing wire attached to a larger radius metallic cylinder, both connected to the same high-voltage supply, are widely used to generate corona discharges in several electrostatic processes such as charging granular materials in electrostatic separation and charging of fibrous media in the manufacturing processes of industrial air filters. The principal aim of this work is to experimentally investigate the effect of geometric dimensions (width and height) of a ground-shielded wire-type dual electrode on the current to a nearby metallic plate. The experimental results of this work clearly show that the current intensity generated by the corona electrode is higher using a narrower shield width. Otherwise, as long as the lower limits of the shield exceed the horizontal axis of the ionizing wire, the shield height does not affect significantly the current intensity produced by the discharge. These experimental results are validated by a series of corona-charging tests of insulating granules in the belt-type electrostatic separator. The quantities of particles recovered in the electro-separator are higher in presence of the shield, with well-chosen dimensions producing the highest possible corona current. These results may help to formulate some recommendations concerning the design of this type of electrode configuration. As the shield increases the output current of the electrode and broadens the ionized field, the proposed arrangement may be very useful for various industrial electrostatic processes

Synthesis, structural study and electrochemical properties of copper(II) complexes derived from benzene- and p-toluenesulphonylhydrazones

The synthesis and characterization of benzene- and p-toluenesulphonylhydrazones derived from salicylaldehyde and 2-hydroxy-1-naphthaldehyde and their Cu(II) complexes are reported. The compounds were characterized on the basis of elemental analyses, electronic and IR spectra, magnetic moments, and conductance measurements. The electrochemical behavior of the Cu(II) complexes was investigated in DMSO by cyclic voltammetry (CV), rotating disc electrode (RDE) and coulometry. The oxidative polymerization of the copper complexes on a glassy carbon electrode was carried out in DMSO

A novel biometric authentication approach using ECG and EMG signals

International audienceSecurity biometrics is a secure alternative to traditional methods of identity verification of individuals, such as authentication systems based on user name and password. Recently, it has been found that the electrocardiogram (ECG) signal formed by five successive waves (P, Q, R, S and T) is unique to each individual. In fact, better than any other biometrics' measures, it delivers proof of subject's being alive as extra information which other biometrics cannot deliver. The main purpose of this work is to present a low-cost method for online acquisition and processing of ECG signals for person authentication and to study the possibility of providing additional information and retrieve personal data from an electrocardiogram signal to yield a reliable decision. This study explores the effectiveness of a novel biometric system resulting from the fusion of information and knowledge provided by ECG and EMG (Electromyogram) physiological recordings. It is shown that biometrics based on these ECG/EMG signals offers a novel way to robustly authenticate subjects. Five ECG databases (MIT-BIH, ST-T, NSR, PTB and ECG-ID) and several ECG signals collected in-house from volunteers were exploited. A palm-based ECG biometric system was developed where the signals are collected from the palm of the subject through a minimally intrusive one-lead ECG set-up. A total of 3750 ECG beats were used in this work. Feature extraction was performed on ECG signals using Fourier descriptors (spectral coefficients). Optimum-Path Forest classifier was used to calculate the degree of similarity between individuals. The obtained results from the proposed approach look promising for individuals' authentication

Human Authentication System Based on ECG Signal Using FFT and Random Forests

International audienceno abstrac

Analysis of ECG Using FFT and random Forests for Human Identification Based on LabVIEW

International audienceno abstrac

ECG Based Human Identification Using Random Forests

International audienceSecurity concerns increase as the technology for falsification advances. There are strong evidences that a difficult to falsify biometric trait, the human heartbeat, can be used for identity recognition. Traditional solutions for biometric recognition from electrocardiogram (ECG) signals are limited in its power. They are based on temporal and amplitude distances between detected fiducial points. The current fiducial detection tools are inadequate for this application since the boundaries of waveforms are difficult to detect, locate and define. In this study, the ECG signals were used to identify a total of 120 individuals obtained from four ECG databases obtained from the Physionet database (MIT-BIH, ST-T, NSR, PTB) and an ECG database collected from 40 student volunteers from Paris Est University. Feature extraction from the ECG signals was performed by using Discrete Wavelet Transform (DWT). The Random Forest was then presented for the ECG signals identification. Preliminary experimental results indicate that the system is accurate and can achieve a low false negative rate, low false positive rate and a 100% subject recognition rate for healthy subjects with the reduced set of features