Time-dependent internal Quantum Efficiency and diffusion Modulation Transfer Function of N/P photodiodes

The minority carrier continuity equation has been solved with the Green’s function approach in a N/P photodiode under the low-level injection assumption. The analytical solution obtained with this approach depends on the three spatial coordinates and on time. The diffusion and the collection of the excess minority carriers have been studied during the transitional period corresponding to very short integration times. The internal Quantum Efficiency and the diffusion Modulation Transfer Function have been calculated according to time. The simulations showed that they evolve with time until their steady-state values. When the integration time is very short, this evolution has to be taken into account for the estimation of the sensitivity of a photodiode and the contrast on an image of a sensor based on several adjacent N/P-type photodiodes.     

Ultra performance liquid chromatography – mass spectrometry studies of formalin‐induced alterations of human brain lipidome

The development of ‘omics’ sciences offers new opportunities for the study of neurodegenerative diseases but increases at the same time the sample demand on brain banks that collect and store valuable human post‐mortem tissue. Our study aims to evaluate in lipidomics the potential of formalin‐fixed tissue compared with the cryopreservation method, considered as the gold standard for biochemical research. Two complementary liquid chromatography/mass spectrometry analytical platforms were used on the basis of hybrid quadrupole time‐of‐flight and triple quadrupole mass spectrometers. Untargeted fingerprinting, semitargeted profiling of specific lipid classes and targeted monitoring of lipid species were performed in formalin‐fixed and cryopreserved samples to provide detailed information at the molecular level on the formalin‐induced alterations of the brain tissue. In vitro incubations of lipid standards were also performed to further describe the degradation processes induced by formaldehyde. Phospholipid compounds were found to be extensively hydrolysed, whilst the sphingolipid ones were preserved. N‐methylation and N‐formylation of amine‐containing phospholipids have also been evidenced. These findings show that the potential detrimental effect of formalin on the analytes of interest must be taken into account when analysing formalin‐fixed samples. Copyright © 2014 John Wiley & Sons, Ltd.     

U and Pu separation with U/TEVA resin: Influence of some parameters on chromatographic cycle performances

Journal of Radioanalytical and Nuclear Chemistry - Due to unexpected Pu behavior using the U/TEVA resin and the most-recognized reagents, some key separation stages need to be studied for the...     

Linear stability of WENO schemes coupled with explicit Runge–Kutta schemes

This paper focuses on the results of the linear stability analysis of the finite‐difference weighted essentially non‐oscillatory (WENO) schemes with optimal weights. The standard WENO schemes between the third and 11th order, the order‐optimised WENO schemes of the sixth and eighth order and the bandwidth‐optimised WENO schemes of the third and fourth order are considered. Several explicit Runge–Kutta schemes including the recently published strong stability‐preserving explicit Runge–Kutta schemes are considered for time discretisation. The stability limits as well as dissipation and dispersion properties dependent on the Courant–Friedrichs–Lewy number are presented for a hyperbolic model equation. The different combinations of space and time discretisation schemes are compared in terms of their accuracy and efficiency. For a parabolic model equation, the viscous term is discretised with high‐order central differences. The stability limits for the parabolic problem are presented as well. Numerical results of linear test cases are shown. Copyright © 2011 John Wiley & Sons, Ltd.