6,307 research outputs found
Applications of elastic-viscoplastic constitutive models in dynamic analyses of crack run-arrest events
Applications of nonlinear techniques to the first series of six HSST wide-plate crack-arrest tests that were performed are described. The experiments include crack initiations at low temperatures and relatively long (20 cm) cleavage propagation phases which are terminated by arrest in high temperature regions. Crack arrest are then followed by ductile tearing events. Consequently, the crack front regions are exposed to wide ranges of strain rates and temperatures
Transverse Momentum in Semi-Inclusive Polarized Deep Inelastic Scattering and the Spin-Flavor Structure of the Proton
The non-valence spin-flavor structure of the nucleon extracted from
semi-inclusive measurements of polarized deep inelastic scattering depends
strongly on the transverse momentum of the detected hadrons which are used to
determine the individual polarized sea distributions. This physics may explain
the recent HERMES observation of a positively polarized strange sea through
semi-inclusive scattering, in contrast to the negative strange sea polarization
deduced from inclusive polarized deep inelastic scattering.Comment: 4 pages, revtex style, 2 figure
Synthesis of imide/arylene ether copolymers for adhesives and composite matrices
A series of imide/arylene ether copolymers were prepared from the reaction of an amorphous arylene ether oligomer and a semi-crystalline imide oligomer. These copolymers were thermally characterized and mechanical properties were measured. One block copolymer was endcapped and the molecular weight was controlled to provide a material that displayed good compression moldability and attractive adhesion and composite properties
Finite hadronization time and unitarity in quark recombination model
The effect of finite hadronization time is considered in the recombination
model, and it is shown that the hadron multiplicity turns out to be
proportional to the initial quark density and unitarity is conserved in the
model. The baryon to meson ratio increases rapidly with the initial quark
density due to competition among different channels.Comment: 4 pages in RevTeX, 3 eps figures, to appear in J. Phys.G as a lette
Manifestation of the Roughness-Square-Gradient Scattering in Surface-Corrugated Waveguides
We study a new mechanism of wave/electron scattering in multi-mode
surface-corrugated waveguides/wires. This mechanism is due to specific
square-gradient terms in an effective Hamiltonian describing the surface
scattering, that were neglected in all previous studies. With a careful
analysis of the role of roughness slopes in a surface profile, we show that
these terms strongly contribute to the expression for the inverse attenuation
length (mean free path), provided the correlation length of corrugations is
relatively small. The analytical results are illustrated by numerical data.Comment: 13 pages, 3 figure
Elliptic flow of resonances at RHIC: probing final state interactions and the structure of resonances
We propose the measurement of the elliptic flow of hadron resonances at the
Relativistic Heavy Ion Collider as a tool to probe the amount of hadronic final
state interactions for resonances at intermediate and large transverse momenta.
This can be achieved by looking at systematic deviations of the measured flow
coefficient from the scaling law given by the quark recombination
formalism. Our method can be generalized to explore the structure of exotic
particles, such as the recently found pentaquark .Comment: 5 pages, 2 figures; v2: accepted version for publication in Physical
Review C rapid communication
Er3+Ylif4 Continuous Wave Cascade Laser Operation At 1620 And 2810 Nm At Room-Temperature
For the first time cw, cascade lasing was demonstrated in 1% Er doped yttrium lithium fluoride (YLF) at room temperature at both 1620 and 2810 nm. In addition, cw lasing in Er[1%]:YLF at 1640 nm and in Er[5%]:YLF at 2810 nm at room temperature is reported for the first time in material of such low concentration
Gradient and Amplitude Scattering in Surface-Corrugated Waveguides
We investigate the interplay between amplitude and square-gradient scattering
from the rough surfaces in multi-mode waveguides (conducting quantum wires).
The main result is that for any (even small in height) roughness the
square-gradient terms in the expression for the wave scattering length
(electron mean free path) are dominant, provided the correlation length of the
surface disorder is small enough. This important effect is missed in existing
studies of the surface scattering.Comment: 4 pages, one figur
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