2,065 research outputs found
A precisely controlled, low range humidity system
Development of environmental control system for determining effects of relative humidity and dry heat on inactivation of microorganism
Numerical Study of Wave Propagation in Uniaxially Anisotropic Lorentzian Backward Wave Slabs
The propagation and refraction of a cylindrical wave created by a line
current through a slab of backward wave medium, also called left-handed medium,
is numerically studied with FDTD. The slab is assumed to be uniaxially
anisotropic. Several sets of constitutive parameters are considered and
comparisons with theoretical results are made. Electric field distributions are
studied inside and behind the slab. It is found that the shape of the
wavefronts and the regions of real and complex wave vectors are in agreement
with theoretical results.Comment: 6 pages, figure
Tunneling of Cooper pairs across voltage biased asymmetric single-Cooper-pair transistors
We analyze tunneling of Cooper pairs across voltage biased asymmetric
single-Cooper-pair transistors. Also tunneling of Cooper pairs across two
capacitively coupled Cooper-pair boxes is considered, when the capacitive
coupling and Cooper pair tunneling are provided by a small Josephson junction
between the islands. The theoretical analysis is done at subgap voltages, where
the current-voltage characteristics depend strongly on the macroscopic
eigenstates of the island(s) and their coupling to the dissipative environment.
As the environment we use an impedance which satisfies Re[Z]<<R_Q and a few
LC-oscillators in series with Z. The numerically calculated I-V curves are
compared with experiments where the quantum states of mesoscopic SQUIDs are
probed with inelastic Cooper pair tunneling. The main features of the observed
I-V data are reproduced. Especially, we find traces of band structure in the
higher excited states of the Cooper-pair boxes as well as traces of multiphoton
processes between two Cooper-pair boxes in the regime of large Josephson
coupling.Comment: 9 pages, 9 figures, Revtex
Design requirements for laminar airflow clean rooms and devices
Laminar airflow and airborne contamination control concepts with clean room specifications and laminar flow facility design
Observation of shot-noise-induced asymmetry in the Coulomb blockaded Josephson junction
We have investigated the influence of shot noise on the IV-curves of a single
mesoscopic Josephson junction. We observe a linear enhancement of zero-bias
conductance of the Josephson junction with increasing shot noise power.
Moreover, the IV-curves become increasingly asymmetric. Our analysis on the
asymmetry shows that the Coulomb blockade of Cooper pairs is strongly
influenced by the non-Gaussian character of the shot noise.Comment: 4 pages, 5 figures, RevTE
A Flexible Privacy-preserving Framework for Singular Value Decomposition under Internet of Things Environment
The singular value decomposition (SVD) is a widely used matrix factorization
tool which underlies plenty of useful applications, e.g. recommendation system,
abnormal detection and data compression. Under the environment of emerging
Internet of Things (IoT), there would be an increasing demand for data analysis
to better human's lives and create new economic growth points. Moreover, due to
the large scope of IoT, most of the data analysis work should be done in the
network edge, i.e. handled by fog computing. However, the devices which provide
fog computing may not be trustable while the data privacy is often the
significant concern of the IoT application users. Thus, when performing SVD for
data analysis purpose, the privacy of user data should be preserved. Based on
the above reasons, in this paper, we propose a privacy-preserving fog computing
framework for SVD computation. The security and performance analysis shows the
practicability of the proposed framework. Furthermore, since different
applications may utilize the result of SVD operation in different ways, three
applications with different objectives are introduced to show how the framework
could flexibly achieve the purposes of different applications, which indicates
the flexibility of the design.Comment: 24 pages, 4 figure
Symmetry and reciprocity constraints on diffraction by gratings of quasi-planar particles
Symmetry and reciprocity constraints on polarization state of the field
diffracted by gratings of quasi-planar particles are considered. It is shown
that the optical activity effects observed recently in arrays of quasi-planar
plasmonic particles on a dielectric substrate are due to the reflection of the
field at the air-dielectric slab interface and are proportional to this
reflection coefficient.Comment: 11 pages, 3 figures, 12 references; minor corrections for better
appearanc
Anisotropy and oblique total transmission at a planar negative-index interface
We show that a class of negative index (n) materials has interesting
anisotropic optical properties, manifest in the effective refraction index that
can be positive, negative, or purely imaginary under different incidence
conditions. With dispersion taken into account, reflection at a planar
negative-index interface exhibits frequency selective total oblique
transmission that is distinct from the Brewster effect.
Finite-difference-time-domain simulation of realistic negative-n structures
confirms the analytic results based on effective indices.Comment: to appear in Phys. Rev.
Towards a systematic design of isotropic bulk magnetic metamaterials using the cubic point groups of symmetry
In this paper a systematic approach to the design of bulk isotropic magnetic
metamaterials is presented. The role of the symmetries of both the constitutive
element and the lattice are analyzed. For this purpose it is assumed that the
metamaterial is composed by cubic SRR resonators, arranged in a cubic lattice.
The minimum symmetries needed to ensure an isotropic behavior are analyzed, and
some particular configurations are proposed. Besides, an equivalent circuit
model is proposed for the considered cubic SRR resonators. Experiments are
carried out in order to validate the proposed theory. We hope that this
analysis will pave the way to the design of bulk metamaterials with strong
isotropic magnetic response, including negative permeability and left-handed
metamaterials.Comment: Submitted to Physical Review B, 23 page
Repulsive Casimir Force in Chiral Metamaterials
We demonstrate theoretically that one can obtain repulsive Casimir forces and
stable nanolevitations by using chiral metamaterials. By extending the Lifshitz
theory to treat chiral metamaterials, we find that a repulsive force and a
minimum of the interaction energy exist for strong chirality, under realistic
frequency dependencies and correct limiting values (for zero and infinite
frequencies) of the permittivity, permeability, and chiral coefficients.Comment: 4 pages, 4 figures, letter. submitted to Phys. Rev. Let
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