10,656 research outputs found
Interface creation and stress dynamics in plasma-deposited silicon dioxide films
The stress in amorphous silicon dioxide filmgrown by plasma-assisted deposition was investigated both during and after film growth for continuously and intermittently depositedfilms. It is shown that an intermittent deposition leads to the creation of interfacial regions during film growth, but also causes dynamical structural change in already-deposited film which results in a significantly different stress-thickness profile measured after deposition.Film growth in the continuously depositedfilm was also monitored using an in situ laser reflection technique, and a strong change in stress was detected at about 145nm which was attributed to the onset of island coalescence
Q-Dependent Susceptibilities in Ferromagnetic Quasiperiodic Z-Invariant Ising Models
We study the q-dependent susceptibility chi(q) of a series of quasiperiodic
Ising models on the square lattice. Several different kinds of aperiodic
sequences of couplings are studied, including the Fibonacci and silver-mean
sequences. Some identities and theorems are generalized and simpler derivations
are presented. We find that the q-dependent susceptibilities are periodic, with
the commensurate peaks of chi(q) located at the same positions as for the
regular Ising models. Hence, incommensurate everywhere-dense peaks can only
occur in cases with mixed ferromagnetic-antiferromagnetic interactions or if
the underlying lattice is aperiodic. For mixed-interaction models the positions
of the peaks depend strongly on the aperiodic sequence chosen.Comment: LaTeX2e, 26 pages, 9 figures (27 eps files). v2: Misprints correcte
Comment on ``A new efficient method for calculating perturbative energies using functions which are not square integrable'': regularization and justification
The method recently proposed by Skala and Cizek for calculating perturbation
energies in a strict sense is ambiguous because it is expressed as a ratio of
two quantities which are separately divergent. Even though this ratio comes out
finite and gives the correct perturbation energies, the calculational process
must be regularized to be justified. We examine one possible method of
regularization and show that the proposed method gives traditional quantum
mechanics results.Comment: 6 pages in REVTeX, no figure
Generalized Supersymmetric Perturbation Theory
Using the basic ingredient of supersymmetry, we develop a simple alternative
approach to perturbation theory in one-dimensional non-relativistic quantum
mechanics. The formulae for the energy shifts and wave functions do not involve
tedious calculations which appear in the available perturbation theories. The
model applicable in the same form to both the ground state and excited bound
states, unlike the recently introduced supersymmetric perturbation technique
which, together with other approaches based on logarithmic perturbation theory,
are involved within the more general framework of the present formalism.Comment: 13 pages article in LaTEX (uses standard article.sty). No Figures.
Sent to Ann. Physics (2004
A qualitative case study of ethnic Chinese instrumental music teachers’ perceptions of teacher identity and status at an international school in Hong Kong
STR-808: RE-TESTING OF A FIRE-DAMAGED BRIDGE
A proof load test was performed on a fire-damaged bridge in October 2008 and its load capacity was confirmed. The bridge was then re-opened for full traffic shortly after the load test. It was further repaired in 2009 which included concrete patching and carbon fibre reinforced polymer (CFRP) warping of 6 girders in the main span. The bridge is located at one of the busiest highways of the country with many heavy trucks passing daily. Also, reinforced concrete could deteriorate much faster than usual after the fire accident. In 2014, the Bridge Office was requested to re-test the bridge in order to re-confirm its performance. The re-testing of the bridge was carried out in November 2014, 6 years after the first load test. The objective of this test was to re-confirm the bridge performance. Therefore, strain gauges and linear voltage displacement transducers (LVDT) were installed on the bridge at the locations almost identical to that installed in 2008’s load test. The applied loads were also similar to that from the original load test. This second load test was successfully completed and the load effects from both load tests were compared. It was observed that the bridge performances in 2008 and 2014 were similar. Therefore, the conclusions from the 2008 load test are still applicable
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