232,221 research outputs found
Laboratory discharge studies of a 6 V alkaline lantern-type battery Eveready Energizer no. 528, under various ambient temperatures (-15 deg C and + 22 deg C) and loads (30 omega and 60 omega)
The voltages of two Eveready No. 528 batteries, one the test battery, the other the control battery, were simultaneously recorded as they were discharged across 30 omega loads using a dual chart recorder. The test battery was initially put in a freezer at -15 + or - 3 C. After its voltage had fallen to .6 V, it was brought back out into the room at 22 + or - 3 C. A second run was made with 60 omega loads. Assuming a 3.0 V cut-off, the total energy output of the test battery at -15 C was 26 WHr 30 omega and 35 WHr 60 omega, and the corresponding numbers for the control battery at 22 C were 91 WHr and 100 WHr. When the test battery was subsequently allowed to warm up, the voltage rose above 4 V and the total energy output rose to 80 WHr 30 omega and 82 WHR 60 omega
Omega flight-test data reduction sequence
Computer programs for Omega data conversion, summary, and preparation for distribution are presented. Program logic and sample data formats are included, along with operational instructions for each program. Flight data (or data collected in flight format in the laboratory) is provided by the Ohio University Omega receiver base in the form of 6-bit binary words representing the phase of an Omega station with respect to the receiver's local clock. All eight Omega stations are measured in each 10-second Omega time frame. In addition, an event-marker bit and a time-slot D synchronizing bit are recorded. Program FDCON is used to remove data from the flight recorder tape and place it on data-processing cards for later use. Program FDSUM provides for computer plotting of selected LOP's, for single-station phase plots, and for printout of basic signal statistics for each Omega channel. Mean phase and standard deviation are printed, along with data from which a phase distribution can be plotted for each Omega station. Program DACOP simply copies the Omega data deck a controlled number of times, for distribution to users
Level truncation and the quartic tachyon coupling
We discuss the convergence of level truncation in bosonic open string field
theory. As a test case we consider the calculation of the quartic tachyon
coupling . We determine the exact contribution from states up to
level L=28 and discuss the extrapolation by means of the BST
algorithm. We determine in a self-consistent way both the coupling and the
exponent of the leading correction to at finite that we
assume to be . The results are and
.}Comment: 17 pages, 2 eps figure
Clock synchronization experiments using OMEGA transmissions
The OMEGA transmissions from North Dakota on 13.10 and 12.85 kHz were monitored at several sites using a recently developed OMEGA timing receiver specifically designed for this purpose. The experiments were conducted at Goddard Space Flight Center, Greenbelt, Maryland; U.S. Naval Observatory, Washington, D.C.; and at the NASA tracking station, Rosman, North Carolina. Results show that cycle identification of the two carrier frequencies was made at each test site, thus, coarse time (76 microseconds) from the OMEGA transmitted signals to within the ambiguity period of each OMEGA frequency was extracted. The fine time determination, which was extracted from the phase difference between the received OMEGA signals and locally generated signals, was about + or - 2 microseconds for daytime reception and about + or - 5 microseconds for nighttime reception
Nonanalytic Magnetization Dependence of the Magnon Effective Mass in Itinerant Quantum Ferromagnets
The spin wave dispersion relation in both clean and disordered itinerant
quantum ferromagnets is calculated. It is found that effects akin to
weak-localization physics cause the frequency of the spin-waves to be a
nonanalytic function of the magnetization m. For low frequencies \Omega, small
wavevectors k, and small m, the dispersion relation is found to be of the form
\Omega ~ m^{1-\alpha} k^2, with \alpha = (4-d)/2 (2<d<4) for disordered
systems, and \alpha = (3-d) (1<d<3) for clean ones. In d=4 (disordered) and d=3
(clean), \Omega ~ m ln(1/m) k^2. Experiments to test these predictions are
proposed.Comment: 4 pp., REVTeX, no fig
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