Search results for "dance"
showing 10 items of 2075 documents
Recent progress in electrical impedance tomography
2003
We consider the inverse problem of finding cavities within some body from electrostatic measurements on the boundary. By a cavity we understand any object with a different electrical conductivity from the background material of the body. We survey two algorithms for solving this inverse problem, namely the factorization method and a MUSIC-type algorithm. In particular, we present a number of numerical results to highlight the potential and the limitations of these two methods.
Distribution patterns of epiphytic reed-associated macroinvertebrate communities across European shallow lakes
2021
So far, research on plant-associated macroinvertebrates, even if conducted on a large number of water bodies, has mostly focused on a relatively small area, permitting limited conclusions to be drawn regarding potentially broader geographic effects, including climate. Some recent studies have shown that the composition of epiphytic communities may differ considerably among climatic zones. To assess this phenomenon, we studied macroinvertebrates associated with the common reed Phragmites australis (Cav.) Trin. ex Steud in 46 shallow lakes using a common protocol. The lakes, located in nine countries, covered almost the entire European latitudinal range (from <48°N to 61°N) and captured much …
Analysis of an impedance function of zinc anodic dissolution
2004
Zinc anodic dissolution has been studied by means of electrochemical impedance spectroscopy (EIS). The kinetic study of the oxidation mechanism has allowed us to propose a theoretical impedance function for this system in deaerated sulphate medium. Relevant information on the faradaic process is provided by analysis of the theoretical impedance function. Kinetic parameters of this system can be calculated from the fitting of experimental data to the faradaic impedance function deduced theoretically. The physical measurements of this function are analysed by means of the dependence of simulated EIS spectra on kinetic parameters.
De l'obligation de transparence de l'arbitre
2002
International audience; (Cass. 2e civ., 6 déc. 2001, inédit, Sté Fremarc c/ Sté ITM entreprises)
La désignation d'un arbitre dans un arbitrage antérieur par l'une des parties ne porte pas atteinte à son indépendance
1999
International audience; (TGI Paris, 22 févr. 1998, inédit, SARL SuperCham c/ M. X ; Cass. 1re civ., 16 mars 1999, Rev. arb. 1999. 308, Etat du Qatar c/ Sté Creighton)
A Neural Solution for a Mobile Robot Navigation into Unknown Indoor Environments Using Visual Landmarks
1998
In this paper we present a neural solution for a mobile robot navigation into unknown indoor environments by using landmarks. Robot navigation task is implemented by two groups of processes based on MLP neural networks classifiers: a Low Level Vision System performs obstacle avoidance and corridor following, while an High Level Vision System extracts landmarks contents and performs goal directed navigation. A path-planner manages the two navigation systems and interacts with the robot hardware. The proposed solution is very strong and flexible and can be used to drive a mobile robot in real indoor environments. In the paper experimental results are also reported.
A new apparatus for the study of avoidance conditioning in fishes
1981
An apparatus for the study of avoidance conditioning in fishes is described. The chamber is cylindrical in shape, with shocking electrodes placed above and below the animals, and response is defined as swimming a predetermined distance in either direction along a circumferential path. This apparatus has several advantages over the conventional shuttlebox: (1)There is little constraint on the direction of swimming; (2) the magnitude of response (swimming distance) required for avoidance can easily be varied over a wide range; and (3) variation in the effectiveness of shock with the position of the animal relative to the position of the electrodes is minimized. Some sample data obtained in a …
Comparing the effects of introduced signal crayfish and native noble crayfish on the littoral invertebrate assemblages of boreal lakes
2015
The introduced North American signal crayfish Pacifastacus leniusculus (Dana) has replaced the native noble crayfish (Astacus astacus) in many European freshwaters and can be considered a new component of these ecosystems. The 2 species are apparently similar in many respects, but their ecological equivalence is uncertain and has been little investigated, especially at the whole-lake scale. We compared the effects of the 2 species on the abundance, species richness, and composition of littoral macroinvertebrate assemblages in a set of small- and mediumsized boreal lakes, which included 8 lakes with noble crayfish, 8 lakes with signal crayfish, and 8 lakes without crayfish. We collected semi…
H-2, H-3(+) and the age of molecular clouds and prestellar cores
2012
Measuring the age of molecular clouds and prestellar cores is a difficult task that has not yet been successfully accomplished although the information is of paramount importance to help in understanding and discriminating between different formation scenarios. Most chemical clocks suffer from unknown initial conditions and are therefore difficult to use. We propose a new approach based on a subset of deuterium chemistry that takes place in the gas phase and for which initial conditions are relatively well known. It relies primarily on the conversion of H 3 + into H 2D + to initiate deuterium enrichment of the molecular gas. This conversion is controlled by the ortho/para ratio of H2 that i…
Oxygen depletion in dense molecular clouds: a clue to a low O2 abundance?
2011
Context: Dark cloud chemical models usually predict large amounts of O2, often above observational limits. Aims: We investigate the reason for this discrepancy from a theoretical point of view, inspired by the studies of Jenkins and Whittet on oxygen depletion. Methods: We use the gas-grain code Nautilus with an up-to-date gas-phase network to study the sensitivity of the molecular oxygen abundance to the oxygen elemental abundance. We use the rate coefficient for the reaction O + OH at 10 K recommended by the KIDA (KInetic Database for Astrochemistry) experts. Results: The updates of rate coefficients and branching ratios of the reactions of our gas-phase chemical network, especially N + C…