107,552 research outputs found
Adjustable wrench for electronic connectors
Standard crescent wrench has been modified to provide a means whereby one adjustable tool can be used with all sizes of electronic connectors. The machined wrench jaws provide lugs for engaging the standard size slots on the different connectors
A new puzzle for random interaction
We continue a series of numerical experiments on many-body systems with
random two-body interactions, by examining correlations in ratios in excitation
energies of yrast = 0, 2, 4, 6, 8 states. Previous studies, limited only to
= 0,2,4 states, had shown strong correlations in boson systems but not
fermion systems. By including states and considering different
scatter plots, strong and realistic correlations appear in both boson and
fermion systems. Such correlations are a challenge to explanations of random
interactions.Comment: 4 pages, 4 figure
Method of resolving clock synchronization error and means therefor Patent
Development of method for synchronizing clocks at several ground stations based on signals received from spacecraft or satellite
Coupled Mode Theory of Electron‐Beam Parametric Amplification
A theory of parametric amplification in a filamentary electron beam by transverse fields is developed in coupled mode form. Space charge effects are neglected. In addition to beam modes at the signal frequency, beam modes at frequencies ωn=ω+ω_p, n=0, ±1, ±2…, where ω_p is the pump frequency, are coupled together. A discussion of the general form of the equations is given and reveals the circumstances under which exponential gain or periodic energy transfer between various modes can occur. When applied to quadrupole electric pump fields, a description of the quadrupole amplifiers of Adler, Wade, and Gordon is obtained. This theory is then used to evaluate the noise contribution from synchronous beam modes and higher cyclotron idler modes. Coupling by axially symmetric electric fields and by axially symmetric magnetic fields is discussed, and other amplification schemes suggested. The theory of coupling by axially symmetric fields can also be used to study lens effects on noise in the gun region
A system of regional agricultural land use mapping tested against small scale Apollo 9 color infrared photography of the Imperial Valley (California)
System of regional agricultural land use mapping tested against Apollo 9 color infrared photography of Imperial Valley, Calif
Maximum thickness of amorphous NiZr interlayers formed by a solid-state reaction technique
Formation of the equilibrium intermetallic compound NiZr in sputter deposited Ni/Zr diffusion couples is suppressed by the formation of a metastable amorphous NiZr alloy until a critical thickness of the amorphous NiZr interlayer is reached. The temperature dependence of this critical thickness is studied experimentally. A phenomenological model based on the premise of interfacial heterogeneous nucleation is proposed to understand the evolution of Ni/Zr diffusion couples
A new fault lineament in Southern California
ERTS-1 imagery clearly shows a 50-mile wide tectonic zone across Southern California oriented about 15 deg to the structures of the Transverse Ranges or with an azimuth of 70 deg. The zone is delineated on the imagery by terrian alignments and vegetational differences. A previously undisclosed tectonic lineament extends across the Mojave Desert and appears as a line of crustal upwarping. Pressure which would have caused this plus the occurrence of many thrust faults with the 70 deg azimuth indicate this to be a zone of crustal compression. Recent earthquake epicenters appear to be related to this compression zone rather than the traditional fault network of Southern California
Model space truncation in shell-model fits
We carry out an interacting shell-model study of binding energies and spectra
in the -shell nuclei to examine the effect of truncation of the shell-model
spaces. Starting with a Hamiltonian defined in a larger space and truncating to
the shell, the binding energies are strongly affected by the truncation,
but the effect on the excitation energies is an order of magnitude smaller. We
then refit the matrix elements of the two-particle interaction to compensate
for the space truncation, and find that it is easy to capture 90% of the
binding energy shifts by refitting a few parameters. With the full parameter
space of the two-particle Hamiltonian, we find that both the binding energies
and the excitation energy can be fitted with remaining residual error about 5%
of the average error from the truncation. Numerically, the rms initial error
associated with our Hamiltonian is 3.4 MeV and the remaining residual error is
0.16 MeV. This is comparable to the empirical error found in -shell
interacting shell model fits to experimental data\cite{br06}.Comment: 10 pages, 3 figure
Viscous flow of the Cu47-Ti34-Zr11-Ni8 glass forming alloy
The viscosity of the Cu47-Ti34-Zr11-Ni8 glass forming alloy was determined by beam bending experiments and by a noncontact oscillating drop technique. These viscosity data can be described with the Vogel-Fulcher-Tammann relation. Using the strong/fragile classification of glasses, Cu47-Ti34-Zr11-Ni8 is more fragile than the strong Zr-Ti-Cu-Ni-Be metallic glass formers
Microstructure Controlled Shear Band Pattern Formation and Enhanced Plasticity of Bulk Metallic Glasses Containing in situ Formed Ductile Phase Dendrite Dispersions
Results are presented for a ductile metal reinforced bulk metallic glass matrix composite based on glass forming compositions in the Zr-Ti-Cu-Ni-Be system. Primary dendrite growth and solute partitioning in the molten state yields a microstructure consisting of a ductile crystalline Ti-Zr-Nb β phase, with bcc structure, in a Zr-Ti-Nb-Cu-Ni-Be bulk metallic glass matrix. Under unconstrained mechanical loading organized shear band patterns develop throughout the sample. This results in a dramatic increase in the plastic strain to failure, impact resistance, and toughness of the metallic glass
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