Magnetization Reversal in CsNiIICrIII(CN)6 Coordination Nanoparticles: Unravelling Surface Anisotropy and Dipolar Interaction Effects

CsNiCr(CN)₆ coordination nanoparticles with sizes ranging from 6 to 30 nm are highly diluted in an organic polymer matrix. Their static and dynamic magnetic behaviour allows unravelling of surface anisotropy and interparticle dipolar interaction effects. The single magnetic domain critical size is thus evaluated to be around 22 nm with a blocking temperature of 21 K (at ν = 1 Hz) and an effective energy barrier for the reversal of the magnetization of 426 K.     

A multiparameter wearable physiologic monitoring system for space and terrestrial applications.

A novel, unobtrusive and wearable, multiparameter ambulatory physiologic monitoring system for space and terrestrial applications, termed LifeGuard, is presented. The core element is a wearable monitor, the crew physiologic observation device (CPOD), that provides the capability to continuously record two standard electrocardiogram leads, respiration rate via impedance plethysmography, heart rate, hemoglobin oxygen saturation, ambient or body temperature, three axes of acceleration, and blood pressure. These parameters can be digitally recorded with high fidelity over a 9-h period with precise time stamps and user-defined event markers. Data can be continuously streamed to a base station using a built-in Bluetooth RF link or stored in 32 MB of on-board flash memory and downloaded to a personal computer using a serial port. The device is powered by two AAA batteries. The design, laboratory, and field testing of the wearable monitors are described.     

A Gauss-Newton-like optimization algorithm for“weighted” nonlinear least-squares problems

The Gauss-Newton algorithm is often used to minimize a nonlinear least-squares loss function instead of the original Newton-Raphson algorithm. The main reason is the fact that only first-order derivatives are needed to construct the Jacobian matrix. Some applications as, for instance multivariable system identification, give rise to “weighted” nonlinear least-squares problems for which it can become quite hard to obtain an analytical expression of the Jacobian matrix. To overcome that struggle, a pseudo-Jacobian matrix is introduced, which leaves the stationary points untouched and can be calculated analytically. Moreover, by slightly changing the pseudo-Jacobian matrix, a better approximation of the Hessian can be obtained resulting in faster convergence     

Modelling mechanical properties of spruce and Douglas fir timber by means of X-ray and grain angle measurements for strength grading purpose

This study proposes a model using data from a scanner (X-ray and grain angle measurements) to perform strength grading. The research also includes global measurements of modulus of elasticity (obtained by vibrations and ultrasound methods), static bending stiffness and bending strength of 805 boards of Douglas fir and 437 boards of spruce. This model can be used in an industrial context since it requires low computational time. The results of this study show that the developed model gives better results than the global non-destructive measurements of the elastic modulus commonly used in the industry. It also shows that this improvement is particularly higher in the case of Douglas fir than for spruce. The comparison has been made on both the quality of the mechanical properties assessment and on the improvement of the grading process according to the European standards by using different index.     

A new concept of planar self-reconfigurable modular robot for conveying microparts

Modularity and self-healing are two interesting properties that could help to design more flexible conveyors of micro-objects. In the Smart Blocks project, we propose to design a 2D modular and self-reconfigurable robot composed of centimeter-scale sliding blocks that embed their own actuators and control electronics. This article presents a proof-of-concept of the linkage and of the traveling system as well as an algorithm able to reconfigure a set of blocks from a spatial configuration to another one. Prototype blocks have been realized using electro-permanent magnets which show a good motion speed while saving power consumption during the linkage. Our reconfiguration algorithm is implemented in a simulator software showing in real-time the reconfiguration of the robot.     

Biomonitoring of the adverse effects induced by the chronic exposure to lead and cadmium on kidney function: usefulness of alpha-glutathione S-transferase

A successful prevention of renal diseases induced by occupational exposure to lead (Pb) and/or cadmium (Cd) largely relies on the capability to detect nephrotoxic effects at a stage when they are still reversible or at least not yet compromising renal function. Hence, the aim of this cross-sectional study was to evaluate the usefulness of a set of early biological markers of oxidative stress or nephrotoxicity for the biomonitoring of workers occupationally exposed to Pb and/or Cd in a non-ferrous metal smelter, and gender, age, socioeconomic status, smoking habits, and drug use-matched control individuals. In exposed subjects, mean levels of Pb in blood and urine were also 387.1+/-99.1 microg Pb/L (1.868+/-0.478 micromol Pb/L) and 217.7+/-117.7 microg Pb/g creatinine (1.051+/-0.568 micromol Pb/g creatinine), and mean levels of Cd in blood and urine were 3.26+/-2.11 microg Cd/L (0.029+/-0.019 micromol Cd/L) and 2.51+/-1.89 microg Cd/g creatinine (0.022+/-0.017 micromol Cd/g creatinine), suggesting thereby relatively low occupational exposure levels. Statistically significant variations in zinc protoporphyrin, malondialdehyde, retinol binding protein, alpha-glutathione S-transferase, and urinary protein levels were reported between the two groups, and were closely correlated with Pb and/or Cd exposure levels. Variations in alphaGST levels were closely associated with Pb exposure. Taken together, these results suggest the use of alpha-glutathione S-transferase excretion in urine as a hallmark of early changes in the proximal tubular integrity.     

Performance of Sulfate-reducing Passive Bioreactors for the Removal of Cd and Zn from Mine Drainage in a Cold Climate

Mine Water and the Environment - Passive treatment is a promising, green technology that is increasingly being used for mine drainage treatment. However, several challenges remain concerning its...     

Operational transfer path analysis

One of the tools used to study the NVH behaviour of a system is the transfer path analysis. It aims to identify the operational forces and the propagation paths of the vibrations and is especially interesting in the case when the system is composed of different subsystems. The classical techniques identify the transfer paths when the system is disassembled. This way one eliminates flanking transfer paths. Yet it is very time-consuming and the boundary conditions are not correct anymore. The presented method makes it possible to identify the transfer paths without disassembling the system. The advantages are that the overall testing time is reduced and that the real boundary conditions are present. In this article the theory will be reviewed and it will be validated using data generated by finite element simulations.