77 research outputs found

    Effect of AlN Seed Layer on Crystallographic Characterization of Piezoelectric AlN

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    Ultrathin aluminum nitride (AlN) films are of great interest for integration into nanoelectromechanical systems for actuation and sensing. Given the direct relationship between crystallographic texture and piezoelectric response, x-ray diffraction has become an important metrology step. However, signals from layers deposited below the piezoelectric (PZE) AlN thin film may skew the crystallographic analysis and give misleading results. In this work, we compare the use of a Ti or AlN seed layer on the crystallographic quality of PZE AlN. We also analyze the influence of several AlN seed layer thicknesses on the rocking curve FWHM of PZE AlN and demonstrate an larger effect of the AlN seed layer on the {\theta}-2{\theta} AlN crystallographic peak for increasing AlN seed layer thickness.Comment: 16 pages, 4 figures, 1 tabl

    Local densities, distribution functions, and wave function correlations for spatially resolved shot noise at nanocontacts

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    We consider a current-carrying, phase-coherent multi-probe conductor to which a small tunneling contact is attached. We treat the conductor and the tunneling contact as a phase-coherent entity and use a Green's function formulation of the scattering approach. We show that the average current and the current fluctuations at the tunneling contact are determined by an effective local non-equilibrium distribution function. This function characterizes the distribution of charge-carriers (or quasi-particles) inside the conductor. It is an exact quantum-mechanical expression and contains the phase-coherence of the particles via local partial densities of states, called injectivities. The distribution function is analyzed for different systems in the zero-temperature limit as well as at finite temperature. Furthermore, we investigate in detail the correlations of the currents measured at two different contacts of a four-probe sample, where two of the probes are only weakly coupled contacts. In particular, we show that the correlations of the currents are at zero-temperature given by spatially non-diagonal injectivities and emissivities. These non-diagonal densities are sensitive to correlations of wave functions and the phase of the wave functions. We consider ballistic conductors and metallic diffusive conductors. We also analyze the Aharonov-Bohm oscillations in the shot noise correlations of a conductor which in the absence of the nano-contacts exhibits no flux-sensitivity in the conductance.Comment: 17 pages, 8 figure

    Political Economy of Civil Society

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    This chapter explores the role of civil society in relation to the economy and the polity by focusing on three distinct yet related dimensions: (1) the conceptual history of civil society in relation to political economy; (2) the theory underpinning a political economy of civil society; (3) the implications of a political economy of civil society for policy-making. The main argument is that there is a fundamental difference between ancient and medieval conceptions, which emphasise natural sociability, and modern accounts that accentuate a violent ‘state of nature’. As a result, civil society either reflects the fundamental embeddedness of economic and political processes in social relations or is an artificial construct. The chapter develops a typology of four modern models, provides a theory of the political economy of civil society and outlines a series of policy ideas

    La maturation des immuno-globulines chez l’homme

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    Fongemies a Candida. [Candida fungemia]

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    From 1980 to 1986, 52 patients presented with an episode of fungemia due to Candida species at the Centre Hospitalier Universitaire Vaudois (representing 2% of the patients with positive blood cultures). In 51 of the 52 patients (98%) the infection was nosocomial, occurring after a median hospital stay of 24 days (range 4-250 days). Only 36 patients (69%) presented with an underlying condition (neoplasms in 18 patients, alcoholism in 7, diabetes in 6, immunosuppressive therapy in 5). In 19 patients (37%) an episode of bacteremia occurred prior to fungemia (median time 14 days, range 1-70 days). Candida albicans was the most commonly isolated species (71%). In 50 patients (96%) the episode of fungemia was associated with a significant, although nonspecific, clinical impairment. The digestive tract (38%) and N intravascular catheter (31%) were the two most common portals of entry for the fungemia. 32 patients (62%) received specific antifungal therapy consisting of amphotericin B in 29 patients (median total dose 450 mg, administered either alone or in association) or of ketoconazole in 3 patients. The global mortality was 46% and the fungemia-related mortality was 21%. Global and fungemia-related mortalities were significantly higher in patients not treated with antifungals than in those treated with them (87% versus 30%, p less than 0.001, and 47% versus 11%, p = 0.01 respectively)

    Effect of AlN seed layer on crystallographic characterization of piezoelectric AlN

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    Ultrathin aluminum nitride (AlN) films are of great interest for integration into nanoelectromechanical systems for actuation and sensing. Given the direct relationship between crystallographic texture and piezoelectric (PZE) response, x-ray diffraction has become an important metrology step. However, signals from layers deposited below the PZE AlN thin film may skew the crystallographic analysis and give misleading results. In this work, the authors compare the use of a Ti or AlN seed layer on the crystallographic quality of PZE AlN. The authors also analyze the influence of several AlN seed layer thicknesses on the rocking curve FWHM of PZE AlN and demonstrate a larger effect of the AlN seed layer on the theta-2 theta AlN crystallographic peak for increasing AlN seed layer thickness. Published by the AVS

    A imanência, apresentação de um roteiro de estudo sobre Gilles Deleuze Immanence plan and forms of life presenting a study guide about Gilles Deleuze

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    O texto pretende mostrar um tipo de abordagem e de entrada no texto deleuziano. A partir do problema do fato da não existência de consenso no mundo da vida sentiu-se a necessidade de começar a pensar e formular um conceito de formas de vida. Escolheu-se, para isto, a idéia de plano de imanência e o conceito de multiplicidade virtual de Deleuze. Apresentamos, então, uma espécie de roteiro desse percurso. É o conceito de formas de vida, articulado e pensado a partir de Deleuze, a resposta ao problema da pluralidade e da diferença.<br>This text intends to show a kind of aprproach and introduction to Deleuze's work. Based on the problem of the non-existence of consensus in the world of life, we feel the need to start thinking and formulating the concept of virtual multiplicity. Then we present a kind of guide to do so. The solution to the problem of plurality and difference is the concept of forms of life formulated and thought in acordance with Deleuze
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