13,283 research outputs found
Particle density and non-local kinetic energy density functional for two-dimensional harmonically confined Fermi vapors
We evaluate analytically some ground state properties of two-dimensional
harmonically confined Fermi vapors with isotropy and for an arbitrary number of
closed shells. We first derive a differential form of the virial theorem and an
expression for the kinetic energy density in terms of the fermion particle
density and its low-order derivatives. These results allow an explicit
differential equation to be obtained for the particle density. The equation is
third-order, linear and homogeneous. We also obtain a relation between the
turning points of kinetic energy and particle densities, and an expression of
the non-local kinetic energy density functional.Comment: 7 pages, 2 figure
Statistical Description of Hydrodynamic Processes in Ionic Melts with taking into account Polarization Effects
Statistical description of hydrodynamic processes for ionic melts is proposed
with taking into account polarization effects caused by the deformation of
external ionic shells. This description is carried out by means of the Zubarev
nonequilibrium statistical operator method, appropriate for investigations of
both strong and weak nonequilibrium processes. The nonequilibrium statistical
operator and the generalized hydrodynamic equations that take into account
polarization processes are received for ionic-polarization model of ionic
molten salts when the nonequilibrium averaged values of densities of ions
number, their momentum, dipole momentum and total energy are chosen for the
reduced description parameters. A spectrum of collective excitations is
investigated within the viscoelastic approximation for ion-polarization model
of ionic melts.Comment: 24 pages, RevTex4.1-format, no figure
Shannon entropies of atomic structure factors, off-diagonal order and electron correlation
Shannon entropies of one- and two-electron atomic structure factors in the
position and momentum representations are used to examine the behavior of the
off-diagonal elements of density matrices with respect to the uncertainty
principle and to analyze the effects of electron correlation on off-diagonal
order. We show that electron correlation induces off-diagonal order in position
space which is characterized by larger entropic values. Electron correlation in
momentum space is characterized by smaller entropic values as information is
forced into regions closer to the diagonal. Related off-diagonal correlation
functions are also discussed
Preferred orientation of n-hexane crystallized in silicon nanochannels: A combined x-ray diffraction and sorption isotherm study
We present an x-ray diffraction study on n-hexane in tubular silicon channels
of approximately 10 nm diameter both as a function of the filling fraction f of
the channels and as a function of temperature. Upon cooling, confined n-hexane
crystallizes in a triclinic phase typical of the bulk crystalline state.
However, the anisotropic spatial confinement leads to a preferred orientation
of the confined crystallites, where the crystallographic direction
coincides with the long axis of the channels. The magnitude of this preferred
orientation increases with the filling fraction, which corroborates the
assumption of a Bridgman-type crystallization process being responsible for the
peculiar crystalline texture. This growth process predicts for a channel-like
confinement an alignment of the fastest crystallization direction parallel to
the long channel axis. It is expected to be increasingly effective with the
length of solidifying liquid parcels and thus with increasing f. In fact, the
fastest solidification front is expected to sweep over the full silicon
nanochannel for f=1, in agreement with our observation of a practically perfect
texture for entirely filled nanochannels
Power, norms and institutional change in the European Union: the protection of the free movement of goods
How do institutions of the European Union change? Using an institutionalist approach, this article highlights the interplay between power, cognitive limits, and the normative order that underpins institutional settings and assesses their impact upon the process of institutional change. Empirical evidence from recent attempts to reinforce the protection of the free movement of goods in the EU suggests that, under conditions of uncertainty, actors with ambiguous preferences assess attempts at institutional change on the basis of the historically defined normative order which holds a given institutional structure together. Hence, path dependent and incremental change occurs even when more ambitious and functionally superior proposals are on offer
Practical dispersion relations for strongly coupled plasma fluids
Very simple explicit analytical expressions are discussed, which are able to
describe the dispersion relations of longitudinal waves in strongly coupled
plasma systems such as one-component plasma and weakly screened Yukawa fluids
with a very good accuracy. Applications to other systems with soft pairwise
interactions are briefly discussed.Comment: 11 pages, 3 figures; Related to arXiv:1711.0615
EVALUASI CAPAIAN PENERAPAN EARLY WARNING ALERT SYSTEM DI PROPINSI SULAWESI UTARA TAHUN 2015
Kementerian Kesehatan bekerjasama dengan WHO dan the United States Centers for Disease Control and Prevention (US CDC) membangun suatu sistem dalam upaya kewaspadaan dini dan respon terhadap penyakit â penyakit potensial KLB. Sistem ini dikenal dengan nama Early Warning Alert and Response System (EWARS) atau Sistem Kewaspadaan Dini dan Respon (SKDR). Sistem Kewaspadaan Dini dan Respon merupakan suatu system yang berfungsi untuk mengetahui pergerakan suatu penyakit menular tertentu dari waktu ke waktu dengan memberikan sinyal atau âalertâ bila jumlah kasusnya melebihi nilai ambang yang telah ditentukan. Jenis penelitian ini adalah penelitian deskripsi dengan menilai kelengkapan data dan ketepatan waktu pelaporan melalui aplikasi e-wars. Hasil penelitian menemukan Adanya penurunan tingkat kelengkapan dan ketepatan laporan pada tahun 2015, dibandingkan dengan tahun 2014. Kurangnya kapasitas tenaga kesehatan di bidang Surveilans dan Imunisasi yang ada di kabupaten/kota dan puskesmas-puskesmas sehingga program EWARS belum berjalan semaksimal mungkin. Masih ada puskesmas-puskesmas di daerah tertantu seperti di Talaud, Sangihe, Sitaro yang belum terjangkau jaringan internet atau sinyal. Aplikasi EWARS yang bermasalah atau rusak. Alur pelaporan penyakit yang prosesnya masih tergolong memakan waktu lama. Kata kunci : E-Wars, Capaian, Kelengkapan Data  ABSTRACTThe Ministry of Health in collaboration with WHO and the United States Centers for Disease Control and Prevention (US CDC) builds a system for early awareness and response to potential outbreaks of outbreaks. This system is known as the Early Warning Alert and Response System (EWARS) or the Early Warning and Response System (SKDR). The Early Alert and Response System is a system that have a function to determine the movement of a particular infectious disease from time to time by giving a signal or "alert" if the number of cases exceeds a predetermined threshold value. This type of research is description research by assessing the completeness of the data and the timeliness of reporting through the e-wars application. The result of this study is, there is a decrease in the level of completeness and accuracy of reports in 2015, compared to 2014. Lack of capacity of health workers in the field of surveillance and immunization in regencies / cities and public health centers so that the EWARS program has not run as much as possible. There are still health centers in certain areas such as Talaud, Sangihe, Sitaro which have not been reached by internet or signal networks. EWARS applications that are problematic or damaged. The flow of reporting on diseases whose processes are still relatively long-term. Keywords: e-wars, Performance, Data Completenes
Ab initio wavefunction based methods for excited states in solids: correlation corrections to the band structure of ionic oxides
Ab initio wavefunction based methods are applied to the study of electron
correlation effects on the band structure of oxide systems. We choose MgO as a
prototype closed-shell ionic oxide. Our analysis is based on a local
Hamiltonian approach and performed on finite fragments cut from the infinite
solid. Localized Wannier functions and embedding potentials are obtained from
prior periodic Hartree-Fock (HF) calculations. We investigate the role of
various electron correlation effects in reducing the HF band gap and modifying
the band widths. On-site and nearest-neighbor charge relaxation as well as
long-range polarization effects are calculated. Whereas correlation effects are
essential for computing accurate band gaps, we found that they produce smaller
changes on the HF band widths, at least for this material. Surprisingly, a
broadening effect is obtained for the O 2p valence bands. The ab initio data
are in good agreement with the energy gap and band width derived from
thermoreflectance and x-ray photoemission experiments. The results show that
the wavefunction based approach applied here allows for well controlled
approximations and a transparent identification of the microscopic processes
which determine the electronic band structure
Accurate Computation of the Screening of Scalar Fifth Forces in Galaxies
Screening mechanisms allow light scalar fields to dynamically avoid the
constraints that come from our lack of observation of a long-range fifth force.
Galactic scale tests are of particular interest when the light scalar is
introduced to explain the dark matter or dark energy that dominates our
cosmology. To date, much of the literature that has studied screening in
galaxies has described screening using simplifying approximations. In this
work, we calculate numerical solutions for scalar fields with screening
mechanisms in galactic contexts, and use these to derive new, precise
conditions governing where fifth forces are screened. We show that the commonly
used binary screened/unscreened threshold can predict a fifth force signal in
situations where a fuller treatment does not, leading us to conclude that
existing constraints might be significantly overestimated. We show that various
other approximations of the screening radius provide a more accurate proxy to
screening, although they fail to exactly reproduce the true screening surface
in certain regions of parameter space. As a demonstration of our scheme, we
apply it to an idealised Milky Way and thus identify the region of parameter
space in which the solar system is screened.Comment: 28 pages, 5 figure
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