1,465,112 research outputs found
The lifetime cost of a magnetic refrigerator
The total cost of a 25 W average load magnetic refrigerator using commercial
grade Gd is calculated using a numerical model. The price of magnetocaloric
material, magnet material and cost of operation are considered, and all
influence the total cost. The lowest combined total cost with a device lifetime
of 15 years is found to be in the range \^{+++}$ refrigeration unit. In a
rough life time cost comparison between the magnetic refrigeration device and
such a unit we find similar costs, the former being slightly cheaper, assuming
the cost of the magnet can be recuperated at end of life.Comment: 17 pages, 17 figure
Traffic control system and method
Frequency of carrier received by aircraft is measured and compared with reference to indicate magnitude of Doppler shift. One Doppler frequency range is selected and indicated by digital signal. Difference between frequency is offset of apparent carrier frequency transmitted by aircraft
Magnetoresistance of PrLaOsSb: Disentangling local crystalline-electric-field physics and lattice effects
Resistivity measurements were performed on PrLaOsSb
single crystals at temperatures down to 20 mK and in fields up to 18 T. The
results for dilute-Pr samples ( and 0.67) are consistent with model
calculations performed assuming a singlet crystalline-electric-field (CEF)
ground state. The residual resistivity of these crystals features a smeared
step centered around 9 T, the predicted crossing field for the lowest CEF
levels. The CEF contribution to the magnetoresistance has a
weaker-than-calculated dependence on the field direction, suggesting that
interactions omitted from the CEF model lead to avoided crossing in the
effective levels of the Pr ion. The dome-shaped magnetoresistance
observed for and 0.05 cannot be reproduced by the CEF model, and likely
results from fluctuations in the field-induced antiferroquadrupolar phase
Traffic control system and method Patent
Traffic control system for supersonic transports using synchronous satellite for data relay between vehicles and ground statio
Digital second-order phase-locked loop
A digital second-order phase-locked loop is disclosed in which a counter driven by a stable clock pulse source is used to generate a reference waveform of the same frequency as an incoming waveform, and to sample the incoming waveform at zero-crossover points. The samples are converted to digital form and accumulated over M cycles, reversing the sign of every second sample. After every M cycles, the accumulated value of samples is hard limited to a value SGN = + or - 1 and multiplied by a value delta sub 1 equal to a number of n sub 1 of fractions of a cycle. An error signal is used to advance or retard the counter according to the sign of the sum by an amount equal to the sum
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