11,207 research outputs found

    Parasitic pumping currents in an interacting quantum dot

    Full text link
    We analyze the charge and spin pumping in an interacting dot within the almost adiabatic limit. By using a non-equilibrium Green's function technique within the time-dependent slave boson approximation, we analyze the pumped current in terms of the dynamical constraints in the infinite-U regime. The results show the presence of parasitic pumping currents due to the additional phases of the constraints. The behavior of the pumped current through the quantum dot is illustrated in the spin-insensitive and in the spin-sensitive case relevant for spintronics applications

    Rancang Bangun Aplikasi Pelayanan dan Rekam Medis Calon Tenaga Kerja Indonesia pada AL-HUDA MEDICAL CENTER

    Full text link
    Al-Huda Medical Center is special unit of Al-Huda hospital which manages check-up service for Prospective Indonesian Migrant Worker (CTKI). Al-Huda Medical Center wants to improve the service process and medical record of CTKI using computer system. There are five main problems found in the field regarding this matter, they include (1) all data reports consisting of registration to medical record database is still in paper-based documents, (2) the registration number is processed manually, (3) there is no barcode in health certificate, (4) specimen is labelled using handwriting (5) registration report, medical record, form, and film paper is done manually in terms of calculation and writing. The solution offered for the aforementioned problems is developing a web-based application which is able to manage service process, medical record, and report. Furthermore, this application provides health certificate which fulfills the standardization of the destination country of CTKI. This application also offers the more accurate reports compared to paper-based documentation

    Low energy phases of bilayer Bi predicted by structure search in two dimensions

    Get PDF
    We employ an ab-initio structure search algorithm to explore the configurational space of Bi in quasi two dimensions. A confinement potential restricts the movement of atoms within a pre-defined thickness during structure search calculations within the minima hopping method to find the stable and metastable forms of bilayer Bi. In addition to recovering the two known low-energy structures (puckered monoclinic and buckled hexagonal), our calculations predict three new structures of bilayer Bi. We call these structures the α\alpha, β\beta, and γ\gamma phases of bilayer Bi, which are, respectively, 63, 72, and 83 meV/atom higher in energy than that of the monoclinic ground state, and thus potentially synthesizable using appropriate substrates. We also compare the structural, electronic, and vibrational properties of the different phases. The puckered monoclinic, buckled hexagonal, and β\beta phases exhibit a semiconducting energy gap, whereas α\alpha and γ\gamma phases are metallic. We notice an unusual Mexican-hat type band dispersion leading to a van Hove singularity in the buckled hexagonal bilayer Bi. Notably, we find symmetry-protected topological Dirac points in the electronic spectrum of the γ\gamma phase. The new structures suggest that bilayer Bi provides a novel playground to study distortion-mediated metal-insulator phase transitions

    3D numerical analysis of the unsteady turbulent swirling flow in a conical diffuser using Fluent and OpenFOAM

    Get PDF
    The paper presents three-dimensional numerical investigations of the unsteady swirling flow in a conical diffuser with a precessing vortex rope. The helical vortex breakdown, also known as precessing vortex rope in the engineering literature, benefits from a large body of literature aimed either at elucidating the physics of the phenomenon and building mathematical models, or at developing and testing practical solutions to control the causes and/or the effects. In this paper we investigate the unsteady hydrodynamic fields with a well-known precessing vortex rope computed with the FLUENT and OpenFOAM CFD codes. The main goal is to elucidate the physics of the phenomenon. The three-dimensional computational domain corresponds to the test section of a test rig designed and developed at Politehnica University of Timisoara. The same domain and grid with two millions cells is considered in both codes. The boundary conditions and problem setup are presented for each case. The unsteady pressure fluctuations along to the element of the conical diffuser are recorded. The numerical pressure fluctuations are validated against experimental data measured on the wall of the test rig. Consequently, the fundamental frequency and higher harmonics of the vortex rope is determined by a Fourier analysis

    3D numerical analysis of the unsteady turbulent swirling flow in a conical diffuser using Fluent and OpenFOAM

    Get PDF
    The paper presents three-dimensional numerical investigations of the unsteady swirling flow in a conical diffuser with a precessing vortex rope. The helical vortex breakdown, also known as precessing vortex rope in the engineering literature, benefits from a large body of literature aimed either at elucidating the physics of the phenomenon and building mathematical models, or at developing and testing practical solutions to control the causes and/or the effects. In this paper we investigate the unsteady hydrodynamic fields with a well-known precessing vortex rope computed with the FLUENT and OpenFOAM CFD codes. The main goal is to elucidate the physics of the phenomenon. The three-dimensional computational domain corresponds to the test section of a test rig designed and developed at Politehnica University of Timisoara. The same domain and grid with two millions cells is considered in both codes. The boundary conditions and problem setup are presented for each case. The unsteady pressure fluctuations along to the element of the conical diffuser are recorded. The numerical pressure fluctuations are validated against experimental data measured on the wall of the test rig. Consequently, the fundamental frequency and higher harmonics of the vortex rope is determined by a Fourier analysis

    Reference Profile Correlation Reveals Estrogen-like Trancriptional Activity of Curcumin

    Get PDF
    Background: Several secondary metabolites from herbal nutrient products act as weak estrogens (phytoestrogens), competing with endogenous estrogen for binding to the estrogen receptors and inhibiting steroid converting enzymes. However, it is still unclear whether these compounds elicit estrogen dependent transcription of genes at physiological concentrations. Methods: We compare the effects of physiological concentrations (100 nM) of the two phytoestrogens Enterolactone and Quercetin and the suspected phytoestrogen Curcumin on gene expression in the breast cancer cell line MCF7 with the effects elicited by 17-beta-estradiol (E2). Results: All three phytocompounds have weak effects on gene transcription; most of the E2 genes respond to the phytoestrogens in the same direction though to a much lesser extent and in the order Curcumin > Quercetin > Enterolactone. Gene regulation induced by these compounds was low for genes strongly induced by E2 and similar to the latter for genes only weakly regulated by the classic estrogen. Of interest with regard to the treatment of menopausal symptoms, the survival factor Birc5/survivin and the oncogene MYBL1 are strongly induced by E2 but only marginally by phytoestrogens. Conclusion: This approach demonstrates estrogenic effects of putative phytoestrogens at physiological concentrations and shows, for the first time, estrogenic effects of Curcumin. Copyright (C) 2010 S. Karger AG, Base

    Inclusion for Cultural Education in Museums, Audio and Touch Interaction

    Get PDF
    Inclusive access to culture for all people in institutions, such as museums, is an important issue specified in French laws and is also recognized internationally. This article investigates inclusion of blind and partially blind visitors in museums. The pilot study conducted involves blind, partially blind, and sighted people and observes their perception of audio descriptions and different tactile representations within a museum. 12 participants were asked to experience three different conditions for 3 scenes of the Bayeux Tapestry using inclusive and co-created audio descriptions, simplified swell paper representations, and high relief representations. Overall, a high level of interest was found across all conditions, with multimodality through audio and tactile stimulus found to have enriched participants’ experience. However, more guided tactile exploration would be better. From participants’ feedback, some observations have emerged which could be explored for the development of new technologies to better respond to museum visitors’ expectations
    • …
    corecore