62,186 research outputs found
Interleaving device
An interleaving device for processing energy signals between various logic devices has a first number of spaced energy carrying layer mateials. Each of the first layer materials has a number of juxtaposed conduits passing energy signals through which are passed. Each of the conduits has a longitudinal axis substantially parallel to a diagonal of each of the first layers. A second group of energy carrying materials is arranged between adjacent ones of the spaced first layer materials. Each of the second layer materials has a number of juxtaposed conduits through which the energy signals are also passed. Each of the conduits in the second layer has a longitudinal axis substantially parallel to a diagonal of each of the second layer materials and substantially perpendicular to the axes of the conduits of the first layer materials
Smooth relativistic Hartree-Fock pseudopotentials for H to Ba and Lu to Hg
We report smooth relativistic Hartree-Fock pseudopotentials (also known as
averaged relativistic effective potentials or AREPs) and spin-orbit operators
for the atoms H to Ba and Lu to Hg. We remove the unphysical extremely
non-local behaviour resulting from the exchange interaction in a controlled
manner, and represent the resulting pseudopotentials in an analytic form
suitable for use within standard quantum chemistry codes. These
pseudopotentials are suitable for use within Hartree-Fock and correlated wave
function methods, including diffusion quantum Monte Carlo calculations.Comment: 13 pages, 3 figure
Quantum sine-Gordon dynamics on analogue curved spacetime in a weakly imperfect scalar Bose gas
Using the coherent state functional integral expression of the partition
function, we show that the sine-Gordon model on an analogue curved spacetime
arises as the effective quantum field theory for phase fluctuations of a weakly
imperfect Bose gas on an incompressible background superfluid flow when these
fluctuations are restricted to a subspace of the single-particle Hilbert space.
We consider bipartitions of the single-particle Hilbert space relevant to
experiments on ultracold bosonic atomic or molecular gases, including, e.g.,
restriction to high- or low-energy sectors of the dynamics and spatial
bipartition corresponding to tunnel-coupled planar Bose gases. By assuming full
unitary quantum control in the low-energy subspace of a trapped gas, we show
that (1) appropriately tuning the particle number statistics of the
lowest-energy mode partially decouples the low- and high-energy sectors,
allowing any low-energy single-particle wave function to define a background
for sine-Gordon dynamics on curved spacetime and (2) macroscopic occupation of
a quantum superposition of two states of the lowest two modes produces an
analogue curved spacetime depending on two background flows, with respective
weights continuously dependent on the corresponding weights of the superposed
quantum states.Comment: 12 pages, 1 figur
Amplification of the quantum superposition macroscopicity of a flux qubit by a magnetized Bose gas
We calculate a measure of superposition macroscopicity for a
superposition of screening current states in a superconducting flux qubit
(SFQ), by relating to the action of an instanton trajectory
connecting the potential wells of the flux qubit. When a magnetized
Bose-Einstein condensed (BEC) gas containing
atoms is brought into a proximity of the flux
qubit in an experimentally realistic geometry, we demonstrate the appearance of
a two- to five-fold amplification of over the bare value without
the BEC, by calculating the instantion trajectory action from the
microscopically derived effective flux Lagrangian of a hybrid quantum system
composed of the flux qubit and a spin- atomic Bose gas. Exploiting the
connection between and the maximal metrological usefulness of a
multimode superposition state, we show that amplification of in
the ground state of the hybrid system is equivalent to a decrease in the
quantum Cram\'{e}r-Rao bound for estimation of an externally applied flux. Our
result therefore demonstrates the increased usefulness of the BEC--SFQ hybrid
system as a sensor of ultraweak magnetic fields below the standard quantum
limit.Comment: 10 pages, 2 figure
Electronic position indicator for latching solenoid valves
Electronic circuit connected to solenoid valve coils visually indicates the position of the valve stem. Transient suppression is provided to prevent damaging voltage spikes
Method for reducing snap in magnetic amplifiers
Method of reducing snap in magnetic amplifiers uses a degenerative feedback circuit consisting of a resistor and a separate winding on a magnetic core. The feedback circuit extends amplifier range by allowing it to be used at lower values of output current
Experiments shed new light on nickel-fluorine reactions
Isotopic tracer experiments and scale-impingement experiments show fluorine to be the migrating species through the nickel fluoride scale formed during the fluorination of nickel. This is in contrast to nickel oxide scales, where nickel is the migrating species
An Introduction to Conformal Ricci Flow
We introduce a variation of the classical Ricci flow equation that modifies
the unit volume constraint of that equation to a scalar curvature constraint.
The resulting equations are named the Conformal Ricci Flow Equations because of
the role that conformal geometry plays in constraining the scalar curvature.
These equations are analogous to the incompressible Navier-Stokes equations of
fluid mechanics inasmuch as a conformal pressure arises as a Lagrange
multiplier to conformally deform the metric flow so as to maintain the scalar
curvature constraint. The equilibrium points are Einstein metrics with a
negative Einstein constant and the conformal pressue is shown to be zero at an
equilibrium point and strictly positive otherwise. The geometry of the
conformal Ricci flow is discussed as well as the remarkable analytic fact that
the constraint force does not lose derivatives and thus analytically the
conformal Ricci equation is a bounded perturbation of the classical
unnormalized Ricci equation. That the constraint force does not lose
derivatives is exactly analogous to the fact that the real physical pressure
force that occurs in the Navier-Stokes equations is a bounded function of the
velocity. Using a nonlinear Trotter product formula, existence and uniqueness
of solutions to the conformal Ricci flow equations is proven. Lastly, we
discuss potential applications to Perelman's proposed implementation of
Hamilton's program to prove Thurston's 3-manifold geometrization conjectures.Comment: 52 pages, 1 figur
A video display interface for the LORAN-C navigation receiver development system
A microprocessor-based development system was designed and fabricated for prototype test of navigation receiver designs. During use of this system in the development of low-cost LORAN-C receiver/processor concepts, the limitations of the integral KIM-1 display were severely felt. It was to augment this numerical display that the video character display was produced. The circuit design presented meets the need for a flexible-format display capable of driving a small standard video monitor with only minimal demands upon microprocessor memory and MPU cycles
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