Robust sideslip angles observer for accurate off-road path tracking control

This paper proposes a control strategy to achieve high accurate path tracking in off-road conditions. The approach is based on adaptive and predictive techniques to account for sliding effects and actuator properties. An extended kinematic model is designed using sideslip angles definition. An observer is proposed to estimate online these variables, independently from the reference path and robot velocity. Thanks to the proposed approach, high accurate path tracking can then be achieved whatever the shape of the reference path and the task to be achieved (practical stabilization or moving object tracking).     

Managing the Acronym/Expansion Identi cation Process for Text-Mining Applications

This paper deals with an acronym/de nition extraction approach from textual data (corpora) and the disambiguation of these de nitions (or expansions). Both steps of our global process of acquisition and management of acronyms are precisely described. The first step consists in using markers such as brackets to identify expansion candidates. The alignment of the letters allows to select the acronym/de nition couples. The second step is to de ne the relevant expansion of an acronym in a given context. Our method is based on statistical measurements (Mutual Information, Cubic Mutual Information, Dice Measure) and the results provided by search engines. This paper presents an evaluation of the global process from real data (general and specialized domains).     

Design and performance of a combined secondary ion mass spectrometry-scanning probe microscopy instrument for high sensitivity and high-resolution elemental three-dimensional analysis

State-of-the-art secondary ion mass spectrometry (SIMS) instruments allow producing 3D chemical mappings with excellent sensitivity and spatial resolution. Several important artifacts however arise from the fact that SIMS 3D mapping does not take into account the surface topography of the sample. In order to correct these artifacts, we have integrated a specially developed scanning probe microscopy (SPM) system into a commercial Cameca NanoSIMS 50 instrument. This new SPM module, which was designed as a DN200CF flange-mounted bolt-on accessory, includes a new high-precision sample stage, a scanner with a range of 100 μm in x and y direction, and a dedicated SPM head which can be operated in the atomic force microscopy (AFM) and Kelvin probe force microscopy modes. Topographical information gained from AFM measurements taken before, during, and after SIMS analysis as well as the SIMS data are automatically compiled into an accurate 3D reconstruction using the software program "SARINA," which was developed for this first combined SIMS-SPM instrument. The achievable lateral resolutions are 6 nm in the SPM mode and 45 nm in the SIMS mode. Elemental 3D images obtained with our integrated SIMS-SPM instrument on Al/Cu and polystyrene/poly(methyl methacrylate) samples demonstrate the advantages of the combined SIMS-SPM approach.     

Fall Composition of Storage Lipids is Associated with the Overwintering Strategy of <Emphasis Type="Italic">Daphnia</Emphasis>

Diapause, which occurs through the production of dormant eggs, is a strategy used by some zooplankton to avoid winter months of persistent low temperatures and low food availability. However, reports of active zooplankton under the ice indicate that other strategies also exist. This study was aimed at evaluating whether the composition of storage lipids in the fall differs between diapausing and active overwintering Daphnia. We assessed the quantity of storage lipids and fatty acid (FA) composition of Daphnia species, along with FA content of seston, in six boreal, alpine and subarctic lakes at the onset of winter, and evaluated the association between storage lipids and Daphnia overwintering strategy. We found that active overwintering Daphnia had >55% body fat and the highest FA concentrations. Polyunsaturated FA, especially stearidonic acid (18:4n-3; SDA) and high ratios of n-3:n-6, were preferentially retained to a greater extent in active overwintering Daphnia than in those that entered diapause. Daphnia FA composition was independent of that of the seston diet, indicating that Daphnia adjusted their storage lipids according to the physiological requirements of a given overwintering strategy. The occurrence of an active overwintering strategy has consequences for zooplankton community structure, and can have important implications for the transfer of high-quality energy at higher trophic levels.     

Layered Simple Hydroxides Functionalized by Fluorene‐Phosphonic Acids: Synthesis,Interface Theoretical Insights,and Magnetoelectric Effect

Copper‐ and cobalt‐based layered simple hydroxides (LSH) are successfully functionalized by a series of fluorene mono‐ and diphosphonic acids, using anionic exchange reactions and a preintercalation strategy. The lateral functionalization of the fluorene moieties has only little impact on the overall structure of the obtained layered hybrid materials but it influences the organization of the molecules within the interlamellar spacing. For bulky fluorene (9,9‐dioctyl derivative), luminescence is preserved when inserted into copper and cobalt hydroxydes, whereas it is completely quenched for the other fluorenes. Detailed characterization of the internal structure and chemical bonding properties for copper‐ and cobalt‐based hybrids is performed via ancillary experimental techniques. For the copper‐based LSH class, for which more elusive findings are found, first‐principles molecular dynamics simulations unravel the fundamental stabilizing role of the H‐bonding network promoted within the local environments of the fluorene mono‐ and diphosphonic acids. The cobalt series of compounds constitute a new class of hybrid magnets, with ordering temperatures ranging from 11.8 to 17.8 K and show a clear magnetoelectric effect. This effect appears above a threshold magnetic field, which is null below the magnetic ordering temperature, and it persists in the paramagnetic regime till about 110 K.     

Design and Synthesis of Galactosylated Bifurcated Ligands with Nanomolar Affinity for Lectin LecA from Pseudomonas aeruginosa

Lectin A (LecA) from Pseudomonas aeruginosa is an established virulence factor. Glycoclusters that target LecA and are able to compete with human glycoconjugates present on epithelial cells are promising candidates to treat P. aeruginosa infection. A family of 32 glycodendrimers of generation 0 and 1 based on a bifurcated bis‐galactoside motif have been designed to interact with LecA. The influences both of the central multivalent core and of the aglycon of these glycodendrimers on their affinity toward LecA have been evaluated by use of a microarray technique, both qualitatively for rapid screening of the binding properties and also quantitatively (K_d). This has led to high‐affinity LecA ligands with K_d values in the low nanomolar range (K_d=22 nm for the best one).     

Effect of adding phosphate to drinking water on bacterial growth in slightly and highly corroded pipes

The effect of phosphate addition in drinking water was tested under static conditions as batch tests and under dynamic conditions using continuously fed reactors. Phosphate supplements in batch tests from 0.1 to 2 mg P-PO4 L(-1) did not show any relationship between bacterial growth and phosphate concentration. Dynamic tests in slightly corroded reactor (stainless steel) treated at 1 mg P-PO4 L(-1) showed only a moderate improvement in the growth of microorganisms. On the contrary, phosphate treatment applied to the highly corroded reactor (unlined cast iron) led to an immediate, drastic drop in iron oxide release and bacterial production. Phosphate uptake by the reactor wall was less than 14% with the stainless-steel reactor and 70-90% with the corroded cast iron reactor. Moreover, about 5% of the phosphate associated to corroded iron pipe walls was released for 20 days after the end of treatment.     

Virus recovery from wastewater treatment plant sludges

A virus extraction method which combines elution with a 10% beef-extract with agitation and sonication, was used to recover enteric viruses from 4 types of sludge sampled at a treatment plant and from 2 types of stored sludge. Titers were measured using BGM continuous cell line with the plaque technique. No viruses were recovered from any of the 16 stored sludge samples analysed. All samples of fresh mixed sludge and of activated sludge contained viruses. 44% of digested sludge and 10% of dehydrated sludge samples were positives for virus.     

Model for calculating the refractive index of a III–V semiconductor

An empirical relationship modeled by a theoretical numerical model has been presented for estimating the refractive indices of semiconductors, especially the III–V semiconductors, relative to their energy gaps.

This model is based on the fact that there is a strong correlation between the energy gap and the refractive index of a given material. This physical relationship remains strictly intrinsic and specific to the material considered.

The performance of this model is compared with that of some other numerical models established by other authors. An analysis based on calculations of the errors between this model and the experimental data has also been carried out.

For the first time, the present model is applicable to the whole range of energy gaps, taking into account the fact that the refractive index for an infinite energy gap is equal to one.

Good agreement is observed between the computed values and the refractive indices reported in the literature for well-known semiconductors.