1,057 research outputs found
Simple quasi-exponential slope generator
Circuitry for digitally generating an exponentially decaying wave function permits discrete values to be sampled from the exponential waveform for comparison with a binary number of specified accuracy. This exponential-decay generator employs a simple binary counter to count in the sequence of exponential decay
Digital filter for reducing sampling jitter in digital control systems Patent
Digital filter for reducing jitter in digital control system
Technique minimizes the effects of dropouts on telemetry records
Recorder deficiencies are minimized by using two-channel system to prepare two tapes, each having noise, wow and flutter, and dropout characteristics of channel on which it was made. Processing tapes by computer and combining signals from two channels produce single tape free of dropouts caused by recording process
A method for reducing sampling jitter in digital control systems
Digital phase lock loop system is designed by smoothing the proportional control with a low pass filter. This method does not significantly affect the loop dynamics when the smoothing filter bandwidth is wide compared to loop bandwidth
Synchronizer for random binary data
Simplified binary-data transition detector, for synchronization of relatively noise-free signals, can be used with radio or cable data-control links. It permits reception of binary data in absence of clock signal or self-clocking coder
Digital data transition tracking loop improves data reception
Transition tracking loop eliminates drifts, leakages, and instabilities inherent in analog filters. Major components are the phase detector, loop filter, voltage-controlled oscillator and timing logic
Slatted pen floors reduce Salmonella in market swine held in abattoirs
The objective of this study was to directly compare Salmonella isolation rates from pig slaughtered after 4 hours holding on slatted or solid concrete floors. Seven truckloads (replicates) of market swine ( 120 kg) from a fully integrated farrow-to-slaughter operation were studied. At unloading, groups of pigs (15-30) were sorted to 1) no-hold (20-45 minutes waiting), 2) pens with solid concrete floors (4 hours), 3) slatted concrete floors (4 hours). Postmortem samples were cultured for Salmonella. Those pigs held in pens with slatted floors (63.6%) had significantly (P \u3c 0.05) less Salmonella in their ceca than those held on solid floors (72.7%)
c-axis magnetotransport in CeCoIn
We present the results of out-of-plane electrical transport measurements on
the heavy fermion superconductor CeCoIn at temperatures from 40 mK to 400
K and in magnetic field up to 9 T. For 10 K transport measurements show
that the zero-field resistivity changes linearly with temperature
and extrapolates nearly to zero at 0 K, indicative of non-Fermi-liquid (nFL)
behavior associated with a quantum critical point (QCP). The longitudinal
magnetoresistance (LMR) of CeCoIn for fields applied parallel to the
c-axis is negative and scales as between 50 and 100 K, revealing
the presence of a single-impurity Kondo energy scale K.
Beginning at 16 K a small positive LMR feature is evident for fields less than
3 tesla that grows in magnitude with decreasing temperature. For higher fields
the LMR is negative and increases in magnitude with decreasing temperature.
This sizable negative magnetoresistance scales as from 2.6 K to
roughly 8 K, and it arises from an extrapolated residual resistivity that
becomes negative and grows quadratically with field in the nFL temperature
regime. Applying a magnetic field along the c-axis with B B restores
Fermi-liquid behavior in at less than 130 mK. Analysis of the
resistivity coefficient's field-dependence suggests that the QCP in
CeCoIn is located \emph{below} the upper critical field, inside the
superconducting phase. These data indicate that while high- c-axis transport
of CeCoIn exhibits features typical for a heavy fermion system, low-
transport is governed both by spin fluctuations associated with the QCP and
Kondo interactions that are influenced by the underlying complex electronic
structure intrinsic to the anisotropic CeCoIn crystal structure
Correlation between the Extraordinary Hall Effect and Resistivity
We study the contribution of different types of scattering sources to the
extraordinary Hall effect. Scattering by magnetic nano-particles embedded in
normal-metal matrix, insulating impurities in magnetic matrix, surface
scattering and temperature dependent scattering are experimentally tested. Our
new data, as well as previously published results on a variety of materials,
are fairly interpreted by a simple modification of the skew scattering model
Giant Josephson current through a single bound state in a superconducting tunnel junction
We study the microscopic structure of the Josephson current in a single-mode
tunnel junction with a wide quasiclassical tunnel barrier. In such a junction
each Andreev bound state carries a current of magnitude proportional to the
{\em amplitude} of the normal electron transmission through the junction.
Tremendous enhancement of the bound state current is caused by the resonance
coupling of superconducting bound states at both superconductor-insulator
interfaces of the junction. The possibility of experimental observation of the
single bound state current is discussed.Comment: 11 pages, [aps,preprint]{revtex
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