8,258 research outputs found
Visibility and aerosol measurement by diode-laser random-modulation CW lidar
Examples of diode laser (DL) random-modulation continuous wave (RM-CW) lidar measurements are reported. The ability of the measurement of the visibility, vertical aerosol profile, and the cloud ceiling height is demonstrated. Although the data shown here were all measured at night time, the daytime measurement is, of course, possible. For that purpose, accurate control of the laser frequency to the center frequency of a narrow band filter is required. Now a new system with a frequency control is under construction
Characteristics of the wavelength of ripples on icicles
It is known that the wavelength of the ripples on icicles in nature is of
centimeter-scale. Such study on morphological instability of ice-water
interface during ice growth from flowing supercooled water film with one side
being a free surface has recently been made [K. Ueno, Phys. Rev. E 68, 021603
(2003)]. This is a first theoretical study taking into account the influence of
the shape of the water-air surface on the growth condition of infinitesimal
disturbances of the ice-water interface. A simpler formula to determine the
wavelength of the ripples than that in the previous paper is derived. It seems
that the wavelength of ripples is insensitive to the water supply rates,
diameters of the icicles and surrounding air temperatures. The details of
dependence of the wavelengh of ripples on these parameters are investigated.Comment: 15 pages, 6 figure
Morphological instability of the solid-liquid interface in crystal growth under supercooled liquid film flow and natural convection airflow
Ring-like ripples on the surface of icicles are an example of morphological
instability of the ice-water interface during ice growth under supercooled
water film flow. The surface of icicles is typically covered with ripples of
about 1 cm in wavelength, and the wavelength appears to be almost independent
of external temperature, icicle radius, and volumetric water flow rate. One
side of the water layer consists of the water-air surface and growing ice is
the other. This is one of the more complicated moving phase boundary problems
with two interfaces. A recent theoretical work [K. Ueno, Phys. Rev. E 68,
(2003) 021603] to address the underlying instability that produces ripples is
based on the assumption of the absence of airflow around icicles. In this
paper, we extend the previous theoretical framework to include a natural
convection airflow ahead of the water-air surface and consider whether the
effect of natural convection airflow on the wavelength of ripples produced on
an ice surface is essential or not.Comment: 19 pages, 5 figure
Ordered phase and phase transitions in the three-dimensional generalized six-state clock model
We study the three-dimensional generalized six-state clock model at values of
the energy parameters, at which the system is considered to have the same
behavior as the stacked triangular antiferromagnetic Ising model and the
three-state antiferromagnetic Potts model. First, we investigate ordered phases
by using the Monte Carlo twist method (MCTM). We confirmed the existence of an
incompletely ordered phase (IOP1) at intermediate temperature, besides the
completely ordered phase (COP) at low-temperature. In this intermediate phase,
two neighboring states of the six-state model mix, while one of them is
selected in the low temperature phase. We examine the fluctuation the mixing
rate of the two states in IOP1 and clarify that the mixing rate is very stable
around 1:1.
The high temperature phase transition is investigated by using
non-equilibrium relaxation method (NERM). We estimate the critical exponents
beta=0.34(1) and nu=0.66(4). These values are consistent with the 3D-XY
universality class. The low temperature phase transition is found to be of
first-order by using MCTM and the finite-size-scaling analysis
Pattern formation in crystal growth under parabolic shear flow
Morphological instability of the solid-liquid interface occuring in a crystal
growing from an undercooled thin liquid being bounded on one side by a free
surface and flowing down inclined plane is investigated by a linear stability
analysis under shear flow. It is found that restoring forces due to gravity and
surface tension is important factor for stabilization of the solid-liquid
interface on long length scales. This is a new stabilizing effect different
from the Gibbs-Thomson effect. A particular long wavelength mode of about 1 cm
of wavy pattern observed on the surface of icicles covered with thin layer of
flowing water is obtained from the dispersion relation including the effect of
flow and restoring forces.Comment: 30 pages, 4 figure
Cultural differences in deliberate counterfeit purchase behavior
Purpose
This paper explores the moderating effects of four personal cultural orientations or PCOs (independence, interdependence, risk aversion and ambiguity intolerance) on the relationships among counterfeit proneness, subjective norms, ethical judgments, product evaluation and purchase intentions for counterfeit products.
Design/methodology/approach
A field study with 840 consumers in Hong Kong using a self-administered structured questionnaire is used to test all the hypotheses.
Finding
Consumers with high (low) scores on interdependence (independence) show stronger positive effects of counterfeit proneness on subjective norms and its effects on the counterfeit evaluation and purchase intentions. In contrast, consumers with high (low) scores on independence (interdependence) show stronger positive effects of counterfeit proneness on ethical judgments and its effects on counterfeit evaluation and purchase intentions. Consumers with higher scores on risk aversion and ambiguity intolerance show negative moderating effects on most of the relationships in the unified conceptual framework.
Research limitations/implications
The authors collected data in Hong Kong, which is predominantly Chinese in culture. Hence, future research in other parts of the world with more diverse cultural values would help test the validity and generalizability of the results.
Practical implications
The findings would be useful for managers of genuine brands to learn more about the process that explains deliberate counterfeit purchase behavior.
Originality/value
The authors extend the unified conceptual framework for deliberate counterfeit purchase behavior by incorporating four PCOs to explore cultural differences in the socio-psychological decision-making process underlying this behavior
ON THE LOW-TEMPERATURE ORDERING OF THE 3D ATIFERROMAGNETIC THREE-STATE POTTS MODEL
The antiferromagnetic three-state Potts model on the simple-cubic lattice is
studied using Monte Carlo simulations. The ordering in a medium temperature
range below the critical point is investigated in detail. Two different regimes
have been observed: The so-called broken sublattice-symmetry phase dominates at
sufficiently low temperatures, while the phase just below the critical point is
characterized by an effectively continuous order parameter and by a fully
restored rotational symmetry. However, the later phase is not the
permutationally sublattice symmetric phase recently predicted by the cluster
variation method.Comment: 20 pages with 9 figures in a single postscript file (compressed and
uuencoded by uufiles -gz -9) plus two big figures in postscript file
Generarized Cubic Model for BaTiO-like Ferroelectric Substance
We propose an order-disorder type microscopic model for BaTiO-like
Ferroelectric Substance. Our model has three phase transitions and four phases.
The symmetry and directions of the polarizations of the ordered phases agree
with the experimental results of BaTiO. The intermediate phases in our
model are known as an incompletely ordered phase, which appears in a
generalized clock model.Comment: 6 pages, 4figure
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