Lithium atom interferometer using laser diffraction : description and experiments

We have built and operated an atom interferometer of the Mach-Zehnder type. The atomic wave is a supersonic beam of lithium seeded in argon and the mirrors and beam-splitters for the atomic wave are based on elastic Bragg diffraction on laser standing waves at 671 nm. We give here a detailed description of our experimental setup and of the procedures used to align its components. We then present experimental signals, exhibiting atomic interference effects with a very high visibility, up to 84.5 %. We describe a series of experiments testing the sensitivity of the fringe visibility to the main alignment defects and to the magnetic field gradient.Comment: 8 avril 200

Non-homogeneous random walks, subdiffusive migration of cells and anomalous chemotaxis

This paper is concerned with a non-homogeneous in space and non-local in time random walk model for anomalous subdiffusive transport of cells. Starting with a Markov model involving a structured probability density function, we derive the non-local in time master equation and fractional equation for the probability of cell position. We show the structural instability of fractional subdiffusive equation with respect to the partial variations of anomalous exponent. We find the criteria under which the anomalous aggregation of cells takes place in the semi-infinite domain.Comment: 18 pages, accepted for publicatio

The Silences Framework: A Method for researching sensitive themes and marginalized health perspectives (English version)

Objective: To describe the experience of applying of The Silences Framework to underpin health research investigating Tuberculosis/HIV/AIDS coinfection . Method: The Silences Framework originally developed following a study exploring the decisions and silences surrounding black Caribbean men living in England, discussing the themes 'sexual health' and 'ethnicity'. Following this study a conceptual a theory for research on sensitive issues and health care of marginalized populations was developed called 'Screaming Silences' which forms the foundation of The Silences Framework. Screaming Silences define research areas and experiences that are poorly studied, little understood or silenced. Results: The Silences Framework supports researchers in revealing "silences" in the subjects they study - as such results may reflect how beliefs, values, and experiences of some groups influence their health. This framework provides the application of four complementary stages: working the silences, hearing silences, voicing silences and working with the silences. The analysis occurs cyclically and can be repeated as long as the silences inherent in a study are not revealed. Conclusion: this article presents The Silences Framework and the application of the notion of "sounds of silence", mapping an antiessentialist theoretical framework for its use in sensitive research in health and nursing areas, being a reference for other researchers in studies involving marginalized populations. KEYWORDS: Inequalities in health. Methods. Nursing. Coinfection. Research. Tuberculosis. Acquired immunodeficiency syndrome

Contribution à la connaissance de Alces palmatus Ham. Smith dans le Quaternaire de la Roumanie

researc

Modélisation des sources de bruit dans les dispositifs MOS

Modeling of noise sources in MOS devicesWe present in this work an investigation of the physical origins of the two main noise sources in MOS devices. In the first part, we interest to the flicker noise and its detailed derivation’s. The thermal noise is discussed in the second part with the explanation of the channel length impact in this noise. At next, we present briefly the induced gate noise

Weakly non-linear dynamics in reaction -- diffusion systems with L\'{e}vy flights

Reaction--diffusion equations with a fractional Laplacian are reduced near a long wave Hopf bifurcation. The obtained amplitude equation is shown to be the complex Ginzburg-Landau equation with a fractional Laplacian. Some of the properties of the normal complex Ginzburg-Landau equation are generalised for the fractional analogue. In particular, an analogue of Kuramoto-Sivashinsky equation is derived

Derrubando Mitos: Como Evitar os Nove Equívocos Básicos no Mundo dos Negócios

Em Derrubando Mitos – Como evitar os nove equívocos básicos no mundo dos negócios (2008), o autor Phil Rosenzweig vê o mundo da administração com olhos críticos, através da análise profunda, muitas vezes ácida, de grandes best-sellers da área. O livro foi eleito pelo Financial Times, em 2007, como um dos melhores na área de negócios. Rosenzweig, professor do IMD em Lausanne na Suíça e doutor na Wharton School, se propõe a analisar os equívocos mais comuns encontrados nos livros e estudos na área de administração

Continuous Time Random Walks with Internal Dynamics and Subdiffusive Reaction-Diffusion Equations

We formulate the generalized master equation for a class of continuous time random walks in the presence of a prescribed deterministic evolution between successive transitions. This formulation is exemplified by means of an advection-diffusion and a jump-diffusion scheme. Based on this master equation, we also derive reaction-diffusion equations for subdiffusive chemical species, using a mean field approximation

ニジゲン カンイ ズカ システム EASYDRAW II ノ ショウカイ

スーパーコンピュータ SX-12特