117,783 research outputs found
Feasibility study in the application of optical signal analysis to non-destructive testing of complex structures
Advantages of the large time bandwidth product of optical processing are presented. Experiments were performed to study the feasibility of the use of optical spectral analysis for detection of flaws in structural elements excited by random noise. Photographic and electronic methods of comparison of complex spectra were developed. Limitations were explored, and suggestions for further work are offered
Investigation of the Problems of Lunar and Planetary Exploration Annual Report, 1 Dec. 1964 - 30 Nov. 1965
Problems of lunar and planetary exploratio
The joint law of the extrema, final value and signature of a stopped random walk
A complete characterization of the possible joint distributions of the
maximum and terminal value of uniformly integrable martingale has been known
for some time, and the aim of this paper is to establish a similar
characterization for continuous martingales of the joint law of the minimum,
final value, and maximum, along with the direction of the final excursion. We
solve this problem completely for the discrete analogue, that of a simple
symmetric random walk stopped at some almost-surely finite stopping time. This
characterization leads to robust hedging strategies for derivatives whose value
depends on the maximum, minimum and final values of the underlying asset
New effective interaction for -shell nuclei and its implications for the stability of the ==28 closed core
The effective interaction GXPF1 for shell-model calculations in the full
shell is tested in detail from various viewpoints such as binding energies,
electro-magnetic moments and transitions, and excitation spectra. The
semi-magic structure is successfully described for or Z=28 nuclei,
Mn, Fe, Co and Ni, suggesting the
existence of significant core-excitations in low-lying non-yrast states as well
as in high-spin yrast states. The results of odd-odd nuclei, Co
and Cu, also confirm the reliability of GXPF1 interaction in the isospin
dependent properties. Studies of shape coexistence suggest an advantage of
Monte Carlo Shell Model over conventional calculations in cases where
full-space calculations still remain too large to be practical.Comment: 29pages, 26figures, to be published in Physical Review
New T=1 effective interactions for the f5/2 p3/2 p1/2 g9/2 model space; Implications for valence-mirror symmetry and seniority isomers
New shell model Hamiltonians are derived for the T=1 part of the residual
interaction in the f5/2 p3/2 p1/2 g9/2 model space based on the analysis and
fit of the available experimental data for 57Ni-78Ni isotopes and 77Cu-100Sn
isotones. The fit procedure, properties of the determined effective interaction
as well as new results for valence-mirror symmetry and seniority isomers for
nuclei near 78Ni and 100Sn are discussed.Comment: 4 pages, 5 figure
Molecular weight effects on chain pull-out fracture of reinforced polymeric interfaces
Using Brownian dynamics, we simulate the fracture of polymer interfaces
reinforced by diblock connector chains. We find that for short chains the
interface fracture toughness depends linearly on the degree of polymerization
of the connector chains, while for longer chains the dependence becomes
. Based on the geometry of initial chain configuration, we propose a
scaling argument that accounts for both short and long chain limits and
crossover between them.Comment: 5 pages, 3 figure
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