2,705 research outputs found
Perbedaan House Indeks (HI) Berdasarkan Stratifikasi Daerah DBD di Wilayah Kerja UPT Puskesmas Martapura Kecamatan Martapura Kota Tahun 2012
Demam Berdarah Dengue (DBD) disebabkan oleh virus dan disebarkan oleh nyamuk. Penyakit ini adalah salah satu masalah bagi kesehatan masyarakat Indonesia yang cenderung terus menyebar dengan meningkatnya mobilitas dan kepadatan populasi. Dari tahun 2009 sampai dengan 2011 kasus DBD selalu ditemukan di wilayah kerja Puskesmas Martapura. Jika dilihat dari stratifikasi kasus DBD per kelurahan/desa tahun 2012, terdapat 1 kelurahan dan 3 desa yang termasuk dalam kategori daerah endemis DBD serta 7 desa yang termasuk dalam kategori daerah sporadis DBD. Belum pernah dilakukan pemeriksaan House Indeks (HI) oleh petugas P2DBD Puskesmas Martapura dan Dinas Kesehatan Kabupaten Banjar di wilayah kerja Puskesmas Martapura. Penelitian ini merupakan penelitian observasional analitik untuk mengetahui perbedaan HI daerah endemis DBD dengan daerah sporadis DBD di wilayah kerja UPT Puskesmas Martapura. Subjek penelitian adalah HI daerah endemis dan sporadis yang diuji dengan uji statistik Independent 2-samples t-test. Hasil menunjukkan bahwa tidak ada perbedaan HI antara daerah endemik dan sporadis dengue di wilayah kerja Puskesmas Martapura pada tahun 2012
Suppression of Kondo effect in a quantum dot by external irradiation
We demonstrate that the external irradiation brings decoherence in the spin
states of the quantum dot. This effect cuts off the Kondo anomaly in
conductance even at zero temperature. We evaluate the dependence of the DC
conductance in the Kondo regime on the power of irradiation, this dependence
being determined by the decoherence.Comment: 4 pages, 1 figur
Floquet states and persistent currents transitions in a mesoscopic ring
We consider the effect of an oscillating potential on the single-particle
spectrum and the time-averaged persistent current of a one-dimensional
phase-coherent mesoscopic ring with a magnetic flux. We show that in a ring
with an even number of spinless electrons the oscillating potential has a
strong effect on the persistent current when the excited side bands are close
to the eigen levels of a pure ring. Resonant enhancement of side bands of the
Floquet state generates a sign change of the persistent current.Comment: 2 figure
Determination of the complex microwave photoconductance of a single quantum dot
A small quantum dot containing approximately 20 electrons is realized in a
two-dimensional electron system of an AlGaAs/GaAs heterostructure. Conventional
transport and microwave spectroscopy reveal the dot's electronic structure. By
applying a coherently coupled two-source technique, we are able to determine
the complex microwave induced tunnel current. The amplitude of this
photoconductance resolves photon-assisted tunneling (PAT) in the non-linear
regime through the ground state and an excited state as well. The out-of-phase
component (susceptance) allows to study charge relaxation within the quantum
dot on a time scale comparable to the microwave beat period.Comment: 5.5 pages, 6 figures, accepted by Phys. Rev. B (Jan. B15 2001
Singularities, Lax degeneracies and Maslov indices of the periodic Toda chain
The n-particle periodic Toda chain is a well known example of an integrable
but nonseparable Hamiltonian system in R^{2n}. We show that Sigma_k, the k-fold
singularities of the Toda chain, ie points where there exist k independent
linear relations amongst the gradients of the integrals of motion, coincide
with points where there are k (doubly) degenerate eigenvalues of
representatives L and Lbar of the two inequivalent classes of Lax matrices
(corresponding to degenerate periodic or antiperiodic solutions of the
associated second-order difference equation). The singularities are shown to be
nondegenerate, so that Sigma_k is a codimension-2k symplectic submanifold.
Sigma_k is shown to be of elliptic type, and the frequencies of transverse
oscillations under Hamiltonians which fix Sigma_k are computed in terms of
spectral data of the Lax matrices. If mu(C) is the (even) Maslov index of a
closed curve C in the regular component of R^{2n}, then (-1)^{\mu(C)/2} is
given by the product of the holonomies (equal to +/- 1) of the even- (or odd-)
indexed eigenvector bundles of L and Lmat.Comment: 25 pages; published versio
Nonlinear Response of a Kondo system: Direct and Alternating Tunneling Currents
Non - equilibrium tunneling current of an Anderson impurity system subject to
both constant and alternating electric fields is studied. A time - dependent
Schrieffer - Wolff transformation maps the time - dependent Anderson
Hamiltonian onto a Kondo one. Perturbation expansion in powers of the Kondo
coupling strength is carried out up to third order, yielding a remarkably
simple analytical expression for the tunneling current. It is found that the
zero - bias anomaly is suppressed by an ac - field. Both dc and the first
harmonic are equally enhanced by the Kondo effect, while the higher harmonics
are relatively small. These results are shown to be valid also below the Kondo
temperature.Comment: 7 pages, RevTeX, 3 PS figures attached, the article has been
significantly developed: time - dependent Schrieffer - Wolff transformation
is presented in the full form, the results are applied to the change in the
direct current induced by an alternating field (2 figures are new
Resonant Photon-Assisted Tunneling Through a Double Quantum Dot: An Electron Pump From Spatial Rabi Oscillations
The time average of the fully nonlinear current through a double quantum dot,
subject to an arbitrary combination of ac and dc voltages, is calculated
exactly using the Keldysh nonequilibrium Green function technique. When driven
on resonance, the system functions as an efficient electron pump due to Rabi
oscillation between the dots. The pumping current is maximum when the coupling
to the leads equals the Rabi frequency.Comment: 6 pages, REVTEX 3.0, 3 postscript figure
Unconventional Superconductivity in Heavy Fermion Systems
We review the studies on the emergent phases of superconductvity and
magnetism in the -electron derived heavy-fermion (HF) systems by means of
the nuclear-quadrupole-resonance (NQR) under pressure. These studies have
unraveled a rich variety of the phenomena in the ground state of HF systems. In
this article, we highlight the novel phase diagrams of magnetism and
unconventional superconductivity (SC) in CeCuSi, HF antiferromagnets
CeRhIn, and CeIn. A new light is shed on the difference and common
features on the interplay between magnetism and SC on the magnetic criticality.Comment: 15 pages, 13 figures, to appear in J. Phys. Soc. JPN, 74, No.1
(2005), special issue "Kondo Effect- 40 Years after the Discovery
Scattering Theory of Photon-Assisted Electron Transport
The scattering matrix approach to phase-coherent transport is generalized to
nonlinear ac-transport. In photon-assisted electron transport it is often only
the dc-component of the current that is of experimental interest. But
ac-currents at all frequencies exist independently of whether they are measured
or not. We present a theory of photon-assisted electron transport which is
charge and current conserving for all Fourier components of the current. We
find that the photo-current can be considered as an up- and down-conversion of
the harmonic potentials associated with the displacement currents. As an
example explicit calculations are presented for a resonant double barrier
coupled to two reservoirs and capacitively coupled to a gate. Two experimental
situations are considered: in the first case the ac-field is applied via a
gate, and in the second case one of the contact potentials is modulated. For
the first case we show that the relative weight of the conduction sidebands
varies with the screening properties of the system. In contrast to the
non-interacting case the relative weights are not determined by Bessel
functions. Moreover, interactions can give rise to an asymmetry between
absorption and emission peaks. In the contact driven case, the theory predicts
a zero-bias current proportional to the asymmetry of the double barrier. This
is in contrast to the discussion of Tien and Gordon which, in violation of
basic symmetry principles, predicts a zero-bias current also for a symmetric
double barrier.Comment: 15 pages, 6 figures, REVTE
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