1,192 research outputs found
Ghost Chaplygin scalar field model of dark energy
We investigate the correspondence between the ghost and Chaplygin scalar
field dark energy models in the framework of Einstein gravity. We consider a
spatially non-flat FRW universe containing the interacting dark energy with
dark matter. We reconstruct the potential and the dynamics for the Chaplygin
scalar field model according to the evolutionary behavior of the ghost dark
energy which can describe the phantomic accelerated expansion of the universe.Comment: 11 pages, 5 figures, matched to published versio
Tightening the entropic uncertainty bound in the presence of quantum memory
The uncertainty principle is a fundamental principle in quantum physics. It
implies that the measurement outcomes of two incompatible observables can not
be predicted simultaneously. In quantum information theory, this principle can
be expressed in terms of entropic measures. Berta \emph{et al}.
[\href{http://www.nature.com/doifinder/10.1038/nphys1734}{ Nature Phys. 6, 659
(2010) }] have indicated that uncertainty bound can be altered by considering a
particle as a quantum memory correlating with the primary particle. In this
article, we obtain a lower bound for entropic uncertainty in the presence of a
quantum memory by adding an additional term depending on Holevo quantity and
mutual information. We conclude that our lower bound will be tighten with
respect to that of Berta \emph{et al.}, when the accessible information about
measurements outcomes is less than the mutual information of the joint state.
Some examples have been investigated for which our lower bound is tighter than
the Berta's \emph{et al.} lower bound. Using our lower bound, a lower bound for
the entanglement of formation of bipartite quantum states has obtained, as well
as an upper bound for the regularized distillable common randomness.Comment: 6 pages, 1 figure to appear in PRA 201
Metallic multilayers for X-band Bragg reflector applications
We present a structural and high frequency (8.72GHz) electrical characterization of sputter deposited Ti/W, Ti/Ru and Mo/Ti metallic multilayers for potential application as acoustic Bragg reflectors. We prove that all metallic multilayers comprised of different acoustic impedance metals such as Ti, W, Mo are promising candidates for Bragg reflector/bottom electrode in full X-band thin film acoustic resonators. Values for high frequency resistivity of the order of are measured by use of a contact-free/non-invasive sheet resistance method
Interacting viscous entropy-corrected holographic scalar field models of dark energy with time-varying G in modified FRW cosmology
We study the entropy-corrected version of the holographic dark energy (HDE)
model in the framework of modified FRW cosmology. We consider a non-flat
universe filled with an interacting viscous entropy-corrected HDE (ECHDE) with
dark matter. We also include the case of variable gravitational constant G in
our model. We obtain the equation of state and the deceleration parameters of
the interacting viscous ECHDE. Moreover, we reconstruct the potential and the
dynamics of the quintessence, tachyon, K-essence and dilaton scalar field
models according to the evolutionary behavior of the interacting viscous ECHDE
model with time-varying G.Comment: 14 pages, Accepted for publication in Research in Astronomy and
Astrophysic
Universal in vivo Textural Model for Human Skin based on Optical Coherence Tomograms
Currently, diagnosis of skin diseases is based primarily on visual pattern
recognition skills and expertise of the physician observing the lesion. Even
though dermatologists are trained to recognize patterns of morphology, it is
still a subjective visual assessment. Tools for automated pattern recognition
can provide objective information to support clinical decision-making.
Noninvasive skin imaging techniques provide complementary information to the
clinician. In recent years, optical coherence tomography has become a powerful
skin imaging technique. According to specific functional needs, skin
architecture varies across different parts of the body, as do the textural
characteristics in OCT images. There is, therefore, a critical need to
systematically analyze OCT images from different body sites, to identify their
significant qualitative and quantitative differences. Sixty-three optical and
textural features extracted from OCT images of healthy and diseased skin are
analyzed and in conjunction with decision-theoretic approaches used to create
computational models of the diseases. We demonstrate that these models provide
objective information to the clinician to assist in the diagnosis of
abnormalities of cutaneous microstructure, and hence, aid in the determination
of treatment. Specifically, we demonstrate the performance of this methodology
on differentiating basal cell carcinoma (BCC) and squamous cell carcinoma (SCC)
from healthy tissue
Correlation of p-doping in CVD Graphene with Substrate Surface Charges
Correlations between the level of p-doping exhibited in large area chemical vapour deposition (CVD) graphene field effect transistor structures (gFETs) and residual charges created by a variety of surface treatments to the silicon dioxide (SiO(2)) substrates prior to CVD graphene transfer are measured. Beginning with graphene on untreated thermal oxidised silicon, a minimum conductivity (σ(min)) occurring at gate voltage V(g) = 15 V (Dirac Point) is measured. It was found that more aggressive treatments (O(2) plasma and UV Ozone treatments) further increase the gate voltage of the Dirac point up to 65 V, corresponding to a significant increase of the level of p-doping displayed in the graphene. An electrowetting model describing the measured relationship between the contact angle (θ) of a water droplet applied to the treated substrate/graphene surface and an effective gate voltage from a surface charge density is proposed to describe biasing of V(g) at σ(min) and was found to fit the measurements with multiplication of a correction factor, allowing effective non-destructive approximation of substrate added charge carrier density using contact angle measurements
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