919 research outputs found
Coexistence of superconductivity and ferromagnetism in two dimensions
Ferromagnetism is usually considered to be incompatible with conventional
superconductivity, as it destroys the singlet correlations responsible for the
pairing interaction. Superconductivity and ferromagnetism are known to coexist
in only a few bulk rare-earth materials. Here we report evidence for their
coexistence in a two-dimensional system: the interface between two bulk
insulators, LaAlO (LAO) and SrTiO (STO), a system that has been studied
intensively recently. Magnetoresistance, Hall and electric-field dependence
measurements suggest that there are two distinct bands of charge carriers that
contribute to the interface conductivity. The sensitivity of properties of the
interface to an electric field make this a fascinating system for the study of
the interplay between superconductivity and magnetism.Comment: 4 pages, 4 figure
On some physics to consider in numerical simulation of erosive cavitation
This paper discusses several mechanisms in erosive cavitation, which are all important to capture, and study, when assessing the risk of erosion. In particular we introduce the concept of primary and secondary cavitation in order to put emphasis on a particular class of mechanisms: cavitation created in the secondary flow field governed by, e.g., a shedding or collapse of a primary created cavity. These secondary cavities are almost always erosive and have previously not been well described in the literature. The role of cloud cavitation is partly reconsidered and a hypothesis for development of vortex group cavitation, a type of secondary cavitation, is presented. An underlying part of the discussion is how the described cavitation mechanisms influence numerical simulation of cavitation nuisance.http://deepblue.lib.umich.edu/bitstream/2027.42/84223/1/CAV2009-final180.pd
Localization of Two-dimensional Electron Gas in LaAlO3/SrTiO3 Heterostructures
We report strong localization of 2D electron gas in LaAlO3 / SrTiO3 epitaxial
thin-film heterostructures grown on (LaAlO3)0.3-(Sr2AlTaO3)0.7 substrates by
using pulsed laser deposition with in-situ reflection high-energy electron
diffraction. Using longitudinal and transverse magnetotransport measurements,
we have determined that disorder at the interface influences the conduction
behavior, and that increasing the carrier concentration by growing at lower
oxygen partial pressure changes the conduction from strongly localized at low
carrier concentration to metallic at higher carrier concentration, with
indications of weak localization. We interpret this behavior in terms of a
changing occupation of Ti 3d bands near the interface, each with a different
spatial extent and susceptibility to localization by disorder, and differences
in carrier confinement due to misfit strain and point defects.Comment: 12 pages, 4 figure
The spectacular self: Jean-Etienne Liotard's Self-Portrait Laughing
An examination of an eighteenth-century painter's interest in performance as depicted through his self-portraits
The Effect of Directing Groups and Various Substituents on Rhodium-Catalyzed Decarbonylation
The activation of carbon-carbon single bonds is difficult due to their nonpolar nature and kinetic stability. The ability to functionalize these bonds can lead to new methodologies valuable in synthetic pathways. Recently, a new method for decarbonylation of aryl ketones via rhodium catalysis has been developed. This study examines the carbon-carbon bond activation of compounds using nitrogen-directing groups. A palladium catalyzed carbon-carbon coupling reaction was utilized and improved upon for the purpose of creating a variety of starting materials. These species are being used to explore the mechanism of the rhodium-catalyzed decarbonylation reaction
Le succes entrepreneurial : Cas de la région Souss Massa
For years, entrepreneurial success has held the attention of both researchers and decision-makers given its strategic role in job creation and regional development.
In this context, several institutional and governmental programs have been set up in Morocco to encourage business creation and support for entrepreneurs. However, the entrepreneurial success has not lived up to expectations.
In order to understand this problem, this article aims to determine the key factors of entrepreneurial success in the Souss Massa region. To do this, we have treated the theoretical framework addressing the key factors of entrepreneurial success based on three elements: the profile of the entrepreneur, the preparatory elements and the environmental characteristics, on the one hand. On the other hand, we conducted a quantitative study in the form of a questionnaire with a sample of 40 entrepreneurs in the Souss Massa region. The data analysis method adopted is based on a structural equation model. The results obtained showed that the environment of the entrepreneur (the social capital and the accompaniment of the entrepreneur) impact, according to the interviewed entrepreneurs, the success of the project, which reinforces the conclusions of Fafchamps and Minten (1998) who argue that the success of a business depends on social capital and business relationships.
Key words: Entrepreneurship, Success, factors, promotion. Souss Massa region.
JEL Classification : M13, L26
Type of paper: Applied ResearchDepuis des années, le succès entrepreneurial retient l’attention à la fois des chercheurs et des décideurs compte tenu de son rôle stratégique dans la création de l’emploi et le développement des régions.
Dans ce cadre, plusieurs programmes institutionnels et gouvernementaux ont été mis en place au Maroc pour encourager la création de l’entreprise et l’accompagnement des entrepreneurs. Cependant le succès entrepreneurial n’a pas été à la hauteur des espérances.
Dans le but de comprendre ce problème, cet article vise à déterminer les facteurs clés de sucés entrepreneurial dans la région Souss Massa. Pour ce faire, nous avons traité le cadre théorique abordant les facteurs clés de la réussite entrepreneuriale en se basant sur trois éléments : le profil de l’entrepreneur, les éléments préparatifs et les caractéristiques environnementales, d’une part. D’autre part, nous avons mené une étude quantitative sous forme d’un questionnaire auprès d’un échantillon de 40 entrepreneurs de la région Souss Massa. La méthode d’analyse de données adoptée est basée sur un modèle des équations structurelles. Les résultats obtenus ont montré que l’environnement de l’entrepreneur (Le capital social et l’accompagnement de l’entrepreneur) impactent, selon les entrepreneurs interrogés, la réussite du projet, Ce qui renforce les conclusions de Fafchamps et Minten (1998) qui avancent que la réussite d’une entreprise dépend du capital social et des relations d’affaires.
Mots -Clés : L’entrepreneuriat, réussite, facteurs, la promotion, région Souss Massa
Classification JEL : M13, L26
Type de papier : Recherche Appliqué
Conductance asymmetry in point-contacts on epitaxial thin films of Ba(FeCo)As
Point-contact spectroscopy is a powerful tool for probing superconductors.
One of the most common observations in the point-contact spectra on the
recently discovered ferropnictide superconductors is a large conductance
asymmetry with respect to voltage across the point-contact. In this paper we
show that the antisymmetric part of the point-contact spectrum between a silver
tip and an epitaxial thin film of Ba(FeCo)As shows
certain unique features. These features have an interesting evolution with
increasing temperature up to a temperature that is 30% larger than the critical
temperature of the superconductor. We argue that this evolution can be
associated with the rich normal state properties of these materials.Comment: 4 pages, 2 figure
Evaluating an interdisciplinary research project: Lessons learned for organisation, researchers and funders
Interdisciplinary research is often essential to develop the integrated systems understanding needed to manage complex environmental issues that are faced by decision-makers world-wide. The scientific, institutional and funding challenges to interdisciplinary research have been the subject of considerable discussion. Funders remain willing to support such research and to evaluate its impact. In this paper, we develop and apply a set of review concepts to systematically evaluate a large interdisciplinary research project. The project was conducted at a national research organisation that seeks to facilitate interdisciplinary integration. We categorise evaluation concepts as process- and outcome-related and propose five practical management interventions to bridge the concepts to improve interdisciplinary integration. These management interventions are: agree on a conceptual model, incorporate independent review, support synthesisers, foster intra-project communication, and build-in organisational learning. We end with reflections on lessons for the structure of research organisations and of the research team to develop effective interdisciplinary research as well as providing a set of recommendations for interdisciplinary research funders
The in vivo study of cardiac mechano-electric and mechano-mechanical coupling during heart development in zebrafish
In the adult heart, acute adaptation of electrical and mechanical activity to changes in mechanical load occur
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