25,639 research outputs found
Study made of ductility limitations of aluminum-silicon alloys
Study of the relation between microstructure and mechanical properties of aluminum-silicon alloys determines the cause of the variations in properties resulting from differences in solidification rate. It was found that variations in strength are a consequence of variations in ductility and that ductility is inversely proportional to dendrite cell size
Twelve Theses on Reactive Rules for the Web
Reactivity, the ability to detect and react to events, is an
essential functionality in many information systems. In particular, Web
systems such as online marketplaces, adaptive (e.g., recommender) systems,
and Web services, react to events such as Web page updates or
data posted to a server.
This article investigates issues of relevance in designing high-level programming
languages dedicated to reactivity on the Web. It presents
twelve theses on features desirable for a language of reactive rules tuned
to programming Web and Semantic Web applications
High temperature static strain gage alloy development program
The literature, applicable theory and finally an experimental program were used to identify new candidate alloy systems for use as the electrical resistance elements in static strain gages up to 1250K. The program goals were 50 hours of use in the environment of a test stand gas turbine engine with measurement accuracies equal to or better than 10 percent of full scale for strains up to + or - 2000 microstrain. As part of this effort, a computerized electrical resistance measurement system was constructed for use at temperatures between 300K and 1250K and heating and cooling rates of 250K/min and 10K/min. The two best alloys were an iron-chromium-aluminum alloy and a palladium base alloy. Although significant progress was made, it was concluded that a considerable additional effort would be needed to fully optimize and evaluate these candidate systems
Dependence of nonlocal Gilbert damping on the ferromagnetic layer type in FM/Cu/Pt heterostructures
We have measured the size effect in nonlocal Gilbert relaxation rate in
FM(t) / Cu (5nm) [/ Pt (2nm)] / Al(2nm) heterostructures, FM = \{
NiFe, CoFeB, pure Co\}. Common behavior is
observed for three FM layers, where the additional relaxation obeys both a
strict inverse power law dependence ,
and a similar magnitude
. As the tested FM layers
span an order of magnitude in spin diffusion length , the
results are in support of spin diffusion, rather than nonlocal resistivity, as
the origin of the effect
RR LYRAE VARIABLE STARS: PULSATIONAL CONSTRAINTS RELEVANT TO THE OOSTERHOFF CONTROVERSY
A solution to the old Oosterhoff controversy is proposed on the basis of a
new theoretical pulsational scenario concerning RR Lyrae cluster variables
(Bono and coworkers). We show that the observed constancy of the lowest
pulsation period in both Oosterhoff type I (OoI) and Oosterhoff type II (OoII)
prototypes (M3, M15) can be easily reproduced only by assuming the canonical
evolutionary horizontal-branch luminosity levels of these Galactic globular
clusters and therefore by rejecting the Sandage period shift effect (SPSE).Comment: postscript file of 7 pages and 2 figures; one non postcript figure is
available upon request; for any problem please write to
[email protected]
Strapdown calibration and alignment study. Volume 1 - Development document Final report
Calibration and alignment techniques for inertial sensing uni
Composition profiles of InAsâGaAs quantum dots determined by medium-energy ion scattering
The composition profile along the [001] growth direction of low-growth-rate InAsâGaAs quantum dots (QDs) has been determined using medium-energy ion scattering (MEIS). A linear profile of In concentration from 100% In at the top of the QDs to 20% at their base provides the best fit to MEIS energy spectra
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