16,370 research outputs found
Zeta-Regularization of the O(N) Non-Linear Sigma Model in D dimensions
The O(N) non-linear sigma model in a -dimensional space of the form , , or is studied, where , and
correspond to flat space, a torus and a sphere, respectively. Using zeta
regularization and the expansion, the corresponding partition functions
and the gap equations are obtained. Numerical solutions of the gap equations at
the critical coupling constants are given, for several values of . The
properties of the partition function and its asymptotic behaviour for large
are discussed. In a similar way, a higher-derivative non-linear sigma model is
investigated too. The physical relevance of our results is discussed.Comment: 26 page
Parasitic pumping currents in an interacting quantum dot
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
Conformal Sector in Quantum Gravity
We discuss the conformal factor dynamics in . Accepting the proposal
that higher-derivative dimensionless terms in the anomaly-induced effective
action may be dropped, we obtain a superrenormalizable (like in )
effective theory for the conformal factor. The one-loop analysis of this theory
gives the anomalous scaling dimension for the conformal factor and provides a
natural mechanism to solve the cosmological constant problem.Comment: 9 pages, Oct 27 199
Rancang Bangun Aplikasi Pelayanan dan Rekam Medis Calon Tenaga Kerja Indonesia pada AL-HUDA MEDICAL CENTER
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
Arthroscopic Anterior Shoulder Stabilization With Incorporation of a Comminuted Bony Bankart Lesion.
Bony Bankart lesions are a common finding in patients with anterior glenohumeral dislocation. Although there are no defined guidelines, small bony Bankart fractures are typically treated arthroscopically with suture anchors. The 2 main techniques used are double- and single-row suture anchor stabilization, with debate over superiority. Biomechanical studies have shown improved reduction and stabilization with the double-row over the single-row suture anchor technique; however, this has not been reported for small or comminuted bony fragments. Both techniques have shown promising preliminary clinical outcomes. In this Technical Note, we describe our preferred technique for arthroscopic instability repair using a single-row all-suture anchor method with the incorporation of a comminuted bony Bankart fragment in the lateral decubitus position
Electrical switching and interferometry of massive Dirac particles in topological insulators constrictions
We investigate the electrical switching of charge and spin transport in a
topological insulator nanoconstriction in a four terminal device. The switch of
the edge channels is caused by the coupling between edge states which overlap
in the constriction and by the tunneling effects at the contacts and therefore
can be manipulated by tuning the applied voltages on the split-gate or by
geometrical etching. The switching mechanism can be conveniently studied by
electron interferometry involving the measurements of the current in different
configurations of the side gates, while the applied bias from the external
leads can be tuned to obtain pure charge or pure spin currents (charge- and
spin- bias configurations). Relevant signatures of quantum confinement effects,
quantum size effects and energy gap are evident in the Fabry-Perot physics of
the device allowing for a full characterization of the charge and spin
currents. The proposed electrical switching behavior offers an efficient tool
to manipulate topological edge state transport in a controllable way.Comment: 10 pages; 14 figure
Stellar population gradients from cosmological simulations: dependence on mass and environment in local galaxies
The age and metallicity gradients for a sample of group and cluster galaxies
from N-body+hydrodynamical simulation are analyzed in terms of galaxy stellar
mass. Dwarf galaxies show null age gradient with a tail of high and positive
values for systems in groups and cluster outskirts. Massive systems have
generally zero age gradients which turn to positive for the most massive ones.
Metallicity gradients are distributed around zero in dwarf galaxies and become
more negative with mass; massive galaxies have steeper negative metallicity
gradients, but the trend flatten with mass. In particular, fossil groups are
characterized by a tighter distribution of both age and metallicity gradients.
We find a good agreement with both local observations and independent
simulations. The results are also discussed in terms of the central age and
metallicity, as well as the total colour, specific star formation and velocity
dispersion.Comment: 9 pages, 5 figures, accepted for publication on MNRA
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