344 research outputs found
Improvement Of A Beam-bending Viscosimeter For Fast Measurement
The beam-bending method is very useful for the viscosity determination of glasses, but the time spent to run the measurement is usually very long. The present note describes the performance of an improved beam-bending viscosimeter at the support stand and loading rod to get the faster measurements of high viscosity glasses with better reliability and precision. The testing time was reduced from 8 to less than 4 hours to run one measurement at three different temperatures (1100, 1200, and 1300°C), with the precision of almost one order of magnitude better (±0.01 for 1g η in poise).6593028302
Anomalous thermal conductivity and local temperature distribution on harmonic Fibonacci chains
The harmonic Fibonacci chain, which is one of a quasiperiodic chain
constructed with a recursion relation, has a singular continuous
frequency-spectrum and critical eigenstates. The validity of the Fourier law is
examined for the harmonic Fibonacci chain with stochastic heat baths at both
ends by investigating the system size N dependence of the heat current J and
the local temperature distribution. It is shown that J asymptotically behaves
as (ln N)^{-1} and the local temperature strongly oscillates along the chain.
These results indicate that the Fourier law does not hold on the harmonic
Fibonacci chain. Furthermore the local temperature exhibits two different
distribution according to the generation of the Fibonacci chain, i.e., the
local temperature distribution does not have a definite form in the
thermodynamic limit. The relations between N-dependence of J and the
frequency-spectrum, and between the local temperature and critical eigenstates
are discussed.Comment: 10 pages, 4 figures, submitted to J. Phys.: Cond. Ma
Influence of Homeotropic Anchoring Walls upon Nematic and Smectic Phases
McMillan liquid crystal model sandwiched between strong homeotropic anchoring
walls is studied. Phase transitions between isotropic, nematic, and smectic A
phases are investigated for wide ranges of an interaction parameter and of the
system thickness. It is confirmed that the anchoring walls induce an increase
in transition temperatures, dissappearance of phase transitions, and an
appearance of non-spontaneous nematic phase. The similarity between influence
of anchoring walls and that of external fields is discussed.Comment: 5 pages, 6 figure
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