11,469 research outputs found
Magnetoresistor monitors relay performance
Magnetoresistor monitors the action of relays without disturbing circuit parameters or degrading relay performance. The magnetoresistor measures the relay magnetic flux produced under transient conditions to establish the characteristic signature of the relay
The reaction pi N -> pi pi N in chiral effective field theory with explicit Delta(1232) degrees of freedom
The reaction pi N -> pi pi N is studied at tree level up to next-to-leading
order in the framework of manifestly covariant baryon chiral perturbation
theory with explicit Delta(1232) degrees of freedom. Using total cross section
data to determine the relevant low-energy constants, predictions are made for
various differential as well as total cross sections at higher energies. A
detailed comparison of results based on the heavy-baryon and relativistic
formulations of chiral perturbation theory with and without explicit Delta
degrees of freedom is given.Comment: 30 pages, 13 figure
Design, Fabrication and Test of Composite Curved Frames for Helicopter Fuselage Structure
Aspects of curved beam effects and their importance in designing composite frame structures are discussed. The curved beam effect induces radial flange loadings which in turn causes flange curling. This curling increases the axial flange stresses and induces transverse bending. These effects are more important in composite structures due to their general inability to redistribute stresses by general yielding, such as in metal structures. A detailed finite element analysis was conducted and used in the design of composite curved frame specimens. Five specimens were statically tested and compared with predicted and test strains. The curved frame effects must be accurately accounted for to avoid premature fracture; finite element methods can accurately predict most of the stresses and no elastic relief from curved beam effects occurred in the composite frames tested. Finite element studies are presented for comparative curved beam effects on composite and metal frames
Complex-mass renormalization in hadronic EFT: applicability at two-loop order
We discuss the application of the complex-mass scheme to multi-loop diagrams
in hadronic effective field theory by considering as an example a two-loop
self-energy diagram. We show that the renormalized two-loop diagram satisfies
the power counting.Comment: 8 pages, 2 figures, version accepted for publication in EPJ
Test instrumentation evaluates electrostatic hazards in fluid system
RJ-1 fuel surface potential is measured with a probe to determine the degree of hazard originating from static electricity buildup in the hydraulic fluid. The probe is mounted in contact with the fluid surface and connected to an electrostatic voltmeter
Concentration for One and Two Species One-Dimensional Reaction-Diffusion Systems
We look for similarity transformations which yield mappings between different
one-dimensional reaction-diffusion processes. In this way results obtained for
special systems can be generalized to equivalent reaction-diffusion models. The
coagulation (A + A -> A) or the annihilation (A + A -> 0) models can be mapped
onto systems in which both processes are allowed. With the help of the
coagulation-decoagulation model results for some death-decoagulation and
annihilation-creation systems are given. We also find a reaction-diffusion
system which is equivalent to the two species annihilation model (A + B ->0).
Besides we present numerical results of Monte Carlo simulations. An accurate
description of the effects of the reaction rates on the concentration in
one-species diffusion-annihilation model is made. The asymptotic behavior of
the concentration in the two species annihilation system (A + B -> 0) with
symmetric initial conditions is studied.Comment: 20 pages latex, uuencoded figures at the en
Injection seeded, diode pumped regenerative ring Nd:YAG amplifier for spaceborne laser ranging technology development
A small, all solid state, regenerative ring amplifier designed as a prototype for space application is discussed. Novel features include dual side pumping of the Nd:YAG crystal and a triangular ring cavity design which minimizes the number of optical components and losses. The amplifier is relatively small (3 ns round trip time) even though standard optical elements are employed. The ring regeneratively amplifies a 100 ps single pulse by approximately 10(exp 5) at a repetition rate of 10 to 100 Hz. The amplifier is designed to be injection seeded with a pulsed, 100 ps laser diode at 1.06 microns, but another Nd:YAG laser system supplying higher pulse energies was employed for laboratory experiment. This system is a prototype laser oscillator for the Geoscience Laser Ranging System (GLRS) platform. Results on measurements of beam quality, astigmatism, and gain are given
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