8,757 research outputs found
Automatic closed circuit television arc guidance control Patent
Automatic closed circuit television arc guidance control for welding joint
Closed circuit TV system automatically guides welding arc
Closed circuit television /CCTV/ system automatically guides a welding torch to position the welding arc accurately along weld seams. Digital counting and logic techniques incorporated in the control circuitry, ensure performance reliability
A filter spectrometer concept for facsimile cameras
A concept which utilizes interference filters and photodetector arrays to integrate spectrometry with the basic imagery function of a facsimile camera is described and analyzed. The analysis considers spectral resolution, instantaneous field of view, spectral range, and signal-to-noise ratio. Specific performance predictions for the Martian environment, the Viking facsimile camera design parameters, and a signal-to-noise ratio for each spectral band equal to or greater than 256 indicate the feasibility of obtaining a spectral resolution of 0.01 micrometers with an instantaneous field of view of about 0.1 deg in the 0.425 micrometers to 1.025 micrometers range using silicon photodetectors. A spectral resolution of 0.05 micrometers with an instantaneous field of view of about 0.6 deg in the 1.0 to 2.7 micrometers range using lead sulfide photodetectors is also feasible
Bosonic molecules in a lattice: unusual fluid phase from multichannel interactions
We show that multichannel interactions significantly alter the phase diagram
of ultracold bosonic molecules in an optical lattice. Most prominently, an
unusual fluid region intervenes between the conventional superfluid and the
Mott insulator. In it, number fluctuations remain but phase coherence is
suppressed by a significant factor. This factor can be made arbitrarily large,
at least in a two-site configuration. We calculate the phase diagram using
complementary methods, including Gutzwiller mean-field and density matrix
renormalization group (DMRG) calculations. Although we focus on bosonic
molecules without dipolar interactions, we expect multichannel interactions to
remain important for dipolar interacting and fermionic molecules.Comment: 6 pages incl. refs, 4 figure
Emergent Time Scale in Entangled Quantum Dynamics of Ultracold Molecules in Optical Lattices
We derive a novel lattice Hamiltonian, the \emph{Molecular Hubbard
Hamiltonian} (MHH), which describes the essential many body physics of
closed-shell ultracold heteronuclear molecules in their absolute ground state
in a quasi-one-dimensional optical lattice. The MHH is explicitly
time-dependent, making a dynamic generalization of the concept of quantum phase
transitions necessary. Using the Time-Evolving Block Decimation (TEBD)
algorithm to study entangled dynamics, we demonstrate that, in the case of hard
core bosonic molecules at half filling, the MHH exhibits an emergent time scale
over which spatial entanglement grows, crystalline order appears, and
oscillations between rotational states self-damp into an asymptotic
superposition. We show that this time scale is a non-monotonic function of the
physical parameters describing the lattice. We also point out that experimental
mapping of the static phase boundaries of the MHH can be used to measure the
molecular polarizability tensor.Comment: 31 pages, 13 figure
- …