25,650 research outputs found
The third-order law for increments in magnetohydrodynamic turbulence with constant shear
We extend the theory for third-order structure functions in homogeneous
incompressible magnetohydrodynamic (MHD) turbulence to the case in which a
constant velocity shear is present. A generalization is found of the usual
relation [Politano and Pouquet, Phys. Rev. E, 57 21 (1998)] between third-order
structure functions and the dissipation rate in steady inertial range
turbulence, in which the shear plays a crucial role. In particular, the
presence of shear leads to a third-order law which is not simply proportional
to the relative separation. Possible implications for laboratory and space
plasmas are discussed
Caging phenomena in reactions: Femtosecond observation of coherent, collisional confinement
We report striking observations of coherent caging of iodine, above the B state dissociation threshold, by single collisions with rare gas atoms at room-temperature. Despite the random nature of the solute–solvent interaction, the caged population retains coherence of the initially prepared unbound wave packet. We discuss some new concepts regarding dynamical coherent caging and the one-atom cage effect
Generation of non-Gaussian statistics and coherent structures in ideal magnetohydrodynamics
Spectral method simulations of ideal magnetohydrodynamics are used to investigate production of coherent small scale structures, a feature of fluid models that is usually associated with inertial range signatures of nonuniform dissipation, and the associated emergence of non-Gaussian statistics. The near-identical growth of non-Gaussianity in ideal and nonideal cases suggests that generation of coherent structures and breaking of self-similarity are essentially ideal processes. This has important implications for understanding the origin of intermittency in turbulence
Mechanical and rheological properties of selected varieties of peppers.
Stress-relaxation rates for eight varieties of peppers were measured. The specimens were loaded at 454,907 and 1361 grams and allowed to relax for time periods of 3.8 and 30 minutes. Stress levels used were 914, 1828 and 2741 gm/cm2. Floral Gem and Jalapeno varieties of peppers received the most attention
Possible origin of the 0.5 plateau in the ballistic conductance of quantum point contacts
A non-equilibrium Green function formalism (NEGF) is used to study the
conductance of a side-gated quantum point contact (QPC) in the presence of
lateral spin-orbit coupling (LSOC). A small difference of bias voltage between
the two side gates (SGs) leads to an inversion asymmetry in the LSOC between
the opposite edges of the channel. In single electron modeling of transport,
this triggers a spontaneous but insignificant spin polarization in the QPC.
However, the spin polarization of the QPC is enhanced substantially when the
effect of electron-electron interaction is included. The spin polarization is
strong enough to result in the occurrence of a conductance plateau at 0.5G0 (G0
= 2e2/h) in the absence of any external magnetic field. In our simulations of a
model QPC device, the 0.5 plateau is found to be quite robust and survives up
to a temperature of 40K. The spontaneous spin polarization and the resulting
magnetization of the QPC can be reversed by flipping the polarity of the source
to drain bias or the potential difference between the two SGs. These numerical
simulations are in good agreement with recent experimental results for
side-gated QPCs made from the low band gap semiconductor InAs
Ellipsometric measurements of the refractive indices of linear alkylbenzene and EJ-301 scintillators from 210 to 1000 nm
We report on ellipsometric measurements of the refractive indices of LAB-PPO,
Nd-doped LAB-PPO and EJ-301 scintillators to the nearest +/-0.005, in the
wavelength range 210-1000 nm.Comment: 7 pages, 4 figure
Calculation of some properties of the vacuum
In this article, we calculate the dressed quark propagator with the flat
bottom potential in the framework of the rain-bow Schwinger-Dyson equation,
which is determined by mean field approximation of the global colour model
lagrangian. The dressed quark propagator exhibits a dynamical symmetry breaking
phenomenon and gives a constituent quark mass about 392 MeV, which is close to
the value of commonly used constituent quark mass in the chiral quark model.
Then based on the dressed quark propagator, we calculate some properties of the
vacuum, such as quark condensate, mixed quark condensate , four quark condensate , tensor, vacuum susceptibilities. The
numerical results are compatible with the values of other theoretical
approaches.Comment: 10 pages, 2 figures, 3 tables, some writing errors are correcte
Incorporation of Pleurotus sajor-caju powder in cinnamon biscuit: study on nutritional, physical, colour and sensorial properties
Discovery of novel dietary fibre (DF)-rich food ingredient is of great interest to meet the rising
consumer demand for healthy food. Intake of DF-enriched food has been positively associated
with a decreased risk of chronic diseases. Pleurotus sajor-caju (PSC), one of the prominent
edible mushrooms widely cultivated in Malaysia, is useful for its culinary and medicinal
purpose. This study aimed to determine the nutritional, physical, colour and sensorial properties
of cinnamon biscuit formulated with PSC powder as partial replacement (0, 4, 8 and 12%) for
wheat flour. Results indicated that elevated incorporation levels of PSC powder significantly
(P<0.05) increased nutritional values of cinnamon biscuits; with 12% PSC cinnamon biscuit
recorded the highest DF (9.84%), protein (7.85%) and ash (1.00%) content. In texture profile
analyses, slight increment in firmness and reduction in crispiness of the cinnamon biscuits
were detected with increasing levels of PSC powder. PSC-enriched cinnamon biscuits were
reported to have lower L* value (ranged from 65.49 to 69.25) compared to control cinnamon
biscuit (70.84), indicating darker surface colour. In comparison to control cinnamon biscuit,
incorporation of PSC powder up to 8% produced higher scores in term of aroma, colour and
appearance. In summary, incorporation of 8% PSC powder could be an effective way to develop
nutritious cinnamon biscuit without jeopardizing its desirable physical and sensorial properties
Phase Diagram Of The Biham-Middleton-Levine Traffic Model In Three Dimensions
We study numerically the behavior of the Biham-Middleton-Levine traffic model
in three dimensions. Our extensive numerical simulations show that the phase
diagram for this model in three dimensions is markedly different from that in
one and two dimensions. In addition to the full speed moving as well as the
completely jamming phases, whose respective average asymptotic car speeds
equal one and zero, we observe an extensive region of car densities with
a low but non-zero average asymptotic car speed. The transition from this
extensive low average asymptotic car speed region to the completely jamming
region is at least second order. We argue that this low speed region is a
result of the formation of a spatially-limited-extended percolating cluster.
Thus, this low speed phase is present in dimensional
Biham-Middleton-Levine model as well.Comment: Minor clarifications, 1 figure adde
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