5,150 research outputs found
Bell's Theorem from Moore's Theorem
It is shown that the restrictions of what can be inferred from
classically-recorded observational outcomes that are imposed by the no-cloning
theorem, the Kochen-Specker theorem and Bell's theorem also follow from
restrictions on inferences from observations formulated within classical
automata theory. Similarities between the assumptions underlying classical
automata theory and those underlying universally-unitary quantum theory are
discussed.Comment: 12 pages; to appear in Int. J. General System
Instrument manual for the retarding ion mass spectrometer on Dynamics Explorer-1
The retarding ion mass spectrometer (RIMS) for Dynamics Explorer-1 is an instrument designed to measure the details of the thermal plasma distribution. It combines the ion temperature determining capability of the retarding potential analyzer with the compositional capabilities of the mass spectrometer and adds multiple sensor heads to sample all directions relative to the spacecraft ram direction. This manual provides a functional description of the RIMS, the instrument calibration, and a description of the commands which can be stored in the instrument logic to control its operation
Variables Affecting Measurements of Vertical Occlusal Force
Previous studies of occlusal force have provided conflicting results. The purpose of these studies was to determine whether the extent of vertical opening, contralateral occlusal support, or head posture influenced vertical occlusal forces during swallowing, simulated chewing, and maximum biting effort. Three samples of subjects with normal vertical facial proportions - one each of children, adolescents, and young adults - were evaluated to determine the effects of changes in small (2.5 vs. 6.0 mm) vertical separation of the first molars. A sample of young adults was used to evaluate changes in large (10-40 mm) vertical openings, and a sample of adolescents was used to investigate the effect of contralateral support and head posture. All between-group comparisons were evaluated using non-parametric statistics. For the small vertical openings, there was significantly more vertical occlusal force at 6.0 than 2.5 mm in children during swallowing and chewing but not during maximum biting effort. In adults, there was significantly more force during swallowing at 6.0 than at 2.5 mm separation, but no differences in chewing or maximum biting. Increasingly large vertical openings resulted in a progressive increase in maximum bite force to a maximum at about 20 mm, followed by a decrease and then a second increase to near-maximum force at about 40 mm for young adults. There were no significant differences in vertical force with or without contralateral support or between flexed, normal, and extended head postures at either of the small openings.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68036/2/10.1177_00220345860650020901.pd
The retarding ion mass spectrometer on dynamics Explorer-A
An instrument designed to measure the details of the thermal plasma distribution combines the ion temperature-determining capability of the retarding potential analyzer with the compositional capabilities of the mass spectrometer and adds multiple sensor heads to sample all directions relative to the spacecraft ram directions. The retarding ion mass spectrometer, its operational modes and calibration are described as well as the data reduction plan, and the anticipated results
Loading tests of a wing structure for a hypersonic aircraft
Room-temperature loading tests were conducted on a wing structure designed with a beaded panel concept for a Mach 8 hypersonic research airplane. Strain, stress, and deflection data were compared with the results of three finite-element structural analysis computer programs and with design data. The test program data were used to evaluate the structural concept and the methods of analysis used in the design. A force stiffness technique was utilized in conjunction with load conditions which produced various combinations of panel shear and compression loading to determine the failure envelope of the buckling critical beaded panels The force-stiffness data did not result in any predictions of buckling failure. It was, therefore, concluded that the panels were conservatively designed as a result of design constraints and assumptions of panel eccentricities. The analysis programs calculated strains and stresses competently. Comparisons between calculated and measured structural deflections showed good agreement. The test program offered a positive demonstration of the beaded panel concept subjected to room-temperature load conditions
Radioactive Probes of the Supernova-Contaminated Solar Nebula: Evidence that the Sun was Born in a Cluster
We construct a simple model for radioisotopic enrichment of the protosolar
nebula by injection from a nearby supernova, based on the inverse square law
for ejecta dispersion. We find that the presolar radioisotopes abundances
(i.e., in solar masses) demand a nearby supernova: its distance can be no
larger than 66 times the size of the protosolar nebula, at a 90% confidence
level, assuming 1 solar mass of protosolar material. The relevant size of the
nebula depends on its state of evolution at the time of radioactivity
injection. In one scenario, a collection of low-mass stars, including our sun,
formed in a group or cluster with an intermediate- to high-mass star that ended
its life as a supernova while our sun was still a protostar, a starless core,
or perhaps a diffuse cloud. Using recent observations of protostars to estimate
the size of the protosolar nebula constrains the distance of the supernova at
0.02 to 1.6 pc. The supernova distance limit is consistent with the scales of
low-mass stars formation around one or more massive stars, but it is closer
than expected were the sun formed in an isolated, solitary state. Consequently,
if any presolar radioactivities originated via supernova injection, we must
conclude that our sun was a member of such a group or cluster that has since
dispersed, and thus that solar system formation should be understood in this
context. In addition, we show that the timescale from explosion to the creation
of small bodies was on the order of 1.8 Myr (formal 90% confidence range of 0
to 2.2 Myr), and thus the temporal choreography from supernova ejecta to
meteorites is important. Finally, we can not distinguish between progenitor
masses from 15 to 25 solar masses in the nucleosynthesis models; however, the
20 solar mass model is somewhat preferred.Comment: ApJ accepted, 19 pages, 3 figure
Construction of the Soudan 2 detector
Progress in the construction of the Soudan 2 nucleon decay detector which is being built at the Soudan iron mine in Minnesota is discussed. The expected event rate and characteristics of low energy neutrino events, muon events, multiple muon events, and other cosmic ray phenomena are discussed
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