CMOS level shifters from 0 to 18 V output

A design methodology for level shifters voltage translators, where the output voltage ranges from 0 to 18 V, and the input voltage ranges from 2 to 5.5 V in a 0.6 µm CMOS-HV technology, is presented. This family of circuits have a special interest in the case of implantable medical devices where is common to handle previously unknown voltages either positive or negative, above or below the control logic supply V_DD. Two application examples are presented: a composite switch to control negative stimuli voltage pulses, and a multi-channel programmable charge-pump voltage multiplier, aimed at charging the output capacitors of an IMD.

     

Turbulent mixing and molecular transport in highly under-expanded hydrogen jets

Highly under-expanded hydrogen jets releasing in quiescent air atmosphere are studied using highly resolved numerical simulations accounting for complex multicomponent molecular transport phenomena. In a first step of the analysis, the main overall features of the hydrogen jet structure are described and compared to those of the classical under-expanded air jet at the same nozzle pressure ratio (NPR). Even if the global flow topology remains quite similar in both cases (i.e., hydrogen and air discharges), the modification of both mean density and mean velocity gradients leads to different relative energy levels for each velocity component. The corresponding change of fluid properties mainly leads to an enhanced mixing at the jet periphery. In comparison to the air case, the turbulence development within the internal part of the under-expanded hydrogen jet surrounding the subsonic core also yields a different structure. While a significantly higher peak of streamwise turbulent stress is observed downstream of the reflected shock, the vorticity dynamics is dampened by viscous diffusion and velocity divergence (i.e., volumetric expansion) contributions. Then, the performance of the simplified Hirschfelder and Curtiss approximation of the multicomponent molecular diffusion phenomena is evaluated with respect to the detailed multicomponent transport representation, as deduced from the EGLIB library. The detailed representation of molecular phenomena is shown to have a significant influence on the estimated local levels of hydrogen mass flux, leading to a non-negligible alteration of the global jet structure.     

A current-reuse biomedical amplifier with a NEF < 1

Digital image authenticity is always an imperative question to tackle whenever a digital image is being assessed for its content. Using digital forensic algorithms, the image will be evaluated for various traces left from numerous categories of manipulations including, among others, copy–move operations. Later this is considered an essential block in most digital image forgeries. It results in changing the information incorporated in a scene, hiding information from an image, or emphasizing some parts of the image. In this paper we propose and investigate two main approaches that differ in the feature extraction process in order to detect copy–move traces. In the first method, we use two-dimensional discrete cosine transform. Whereas in the second method, the phase response of Gabor filter is being used. Instead of being applied on the image directly, the two methods are applied over the first, the second or the third principal component of the image after being divided into overlapping blocks. Combining these conditions results in six basic implementations that are investigated under three parameters that must be optimized: block dimension, contrast and similarity thresholds. Results from testing and validation process demonstrate that the highest performance, in terms of false accept rate, is obtained when using Gabor filter associated with the first principal component of the image outperforming a reference method we implemented as well.     

Do sewage treatment plant discharges substantially impair fish reproduction in polluted rivers?

Sewage treatment plants are frequently associated with the release of xenobiotics and, consequently, with alterations of the reproductive function induced by many of these substances in aquatic organisms. In order to assess the impacts of sewage treatment plant (STP) discharges in polluted rivers, two sentinel species (gudgeon Gobio gobio and stoneloach Barbatula barbatula) were caught during their reproductive cycle upstream and downstream two STPs (STP1--Goffontaine, STP2--Wegnez). Gonadosomatic index, histological (testicular and ovarian stages, atretic follicles, intersexuality) and endocrine (sex steroids, aromatase activity, alkali-labile phosphorus) parameters were assayed. In brief, the results revealed no systematic significant differences (p<0.05) between upstream and downstream sites, whatever the STP, species or sampling period. However, stoneloach females displayed some signs of reproductive impairment and endocrine disruption downstream STP1 (reduced GSI, oocyte diameter and ALP concentrations, increased proportion of atretic follicles) and STP2 (changes in gonadal aromatase activity and plasma levels of 11-KT and T). Few significant changes were observed for gudgeon males and females while there were no significant differences between upstream and downstream sites for stoneloach males. Moreover, plasma E(2) concentrations recorded in gudgeon males sampled in all sites were as high as in females and this was confirmed by high ALP levels. Besides, spermatogenesis of gudgeon males was delayed in STP1 upstream and downstream sites compared to the corresponding sites in STP2. These observations for gudgeon males do not seem related to STP discharge but to a probable estrogenicity of the river. Therefore, as shown by the results, stoneloach seemed more sensitive than gudgeon to STP discharges. In the present study, sewage treatment plant discharges do not substantially impair fish reproduction. In this respect, caution is required when generalising negative impacts of STP discharges.     

Polyurethane coatings from liquefied wood containing remains of a copper‐, chromium‐, and boron‐based wood preservative

Preparation of polyurethane wood coatings based on copper‐, chromium‐, and boron (CCB) containing liquefied wood was performed, as an alternative way to manage postconsumed preservative‐contaminated wood. Additionally, we examined the possibility of improvement of selected properties of the liquefied wood‐based coatings by an addition of silica nanoparticles. The constituents of the CCB wood preservative do not exhibit an influence on a liquefaction process and on composition of the liquefied mixture. CCB also does not affect curing of the formulations containing liquefied wood and an isocyanate‐type hardener. Furthermore, influence of CCB on adhesion strength of liquefied wood‐based coatings on a wooden substrate, their hardness, and resistance to scratching and to water, acetone, and alcohol, is not exhibited. However, apart from these, from the applicative point of view, positive results, any improvement of the coating properties by the addition of silica nanoparticles is not shown. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40865.     

Synthesis of 6‐Substituted 7‐Bomoazabicyclo[2.2.1]heptanes via Nucleophilic Addition to 3‐Bromo‐1‐azoniatricyclo[2.2.1.0]‐heptane Bromide

We describe herein an efficient method for the preparation of a functionalised bicyclic framework (6‐substituted 7‐bromo‐aza‐bicyclo[2.2.1]heptane) through the selective opening of the aziridium 2 with organocuprates in up to 90% yield. These interesting chiral building blocks were then utilised as novel ligands in the rearrangement of epoxides to afford chiral allylic alcohols.