3,463 research outputs found
Translation-Rotation Coupling in Transient Grating Experiments : Theoretical and Experimental Evidences
The results of a Transient Grating experiment in a supercooled molecular
liquid of anisotropic molecules and its theoretical interpretation are
presented. These results show the existence of two distinct dynamical
contributions in the response function of this experiment, density and
orientation dynamics. These dynamics can be experimentally disentangled by
varying the polarisation of the probe and diffracted beams and they have been
identified and measured in a Heterodyne Detected experiment performed on
m-toluidine. The results of the theory show a good qualitative agreement with
the measurements at all temperatures.Comment: PDF format, 14 pages including 4 figures, accepted for publication in
EPL. minor modification
Abolishing Exclusive Jurisdiction in the Federal Circuit: A Response to Judge Wood
Part of a symposium of responses to Chief Judge Wood’s suggestion for giving regional circuits a share of the Federal Circuit’s authority over patent law, this article argues that now that a degree of nationwide uniformity in patent law has been achieved, it would be a pity to disrupt it. While Chief Judge Wood is right that the law would improve with percolation, a change in the composition of the court, new procedures for challenging patents in the Patent and Trademark Office, a District Court pilot program, and satellite patent offices will bring to the debate new voices, different kinds of expertise, and diverse experience. It is worth waiting to see how these changes play out
Abolishing Exclusive Jurisdiction in the Federal Circuit: A Response to Judge Wood
Part of a symposium of responses to Chief Judge Wood’s suggestion for giving regional circuits a share of the Federal Circuit’s authority over patent law, this article argues that now that a degree of nationwide uniformity in patent law has been achieved, it would be a pity to disrupt it. While Chief Judge Wood is right that the law would improve with percolation, a change in the composition of the court, new procedures for challenging patents in the Patent and Trademark Office, a District Court pilot program, and satellite patent offices will bring to the debate new voices, different kinds of expertise, and diverse experience. It is worth waiting to see how these changes play out
Morphology of rain water channelization in systematically varied model sandy soils
We visualize the formation of fingered flow in dry model sandy soils under
different raining conditions using a quasi-2d experimental set-up, and
systematically determine the impact of soil grain diameter and surface wetting
property on water channelization phenomenon. The model sandy soils we use are
random closely-packed glass beads with varied diameters and surface treatments.
For hydrophilic sandy soils, our experiments show that rain water infiltrates
into a shallow top layer of soil and creates a horizontal water wetting front
that grows downward homogeneously until instabilities occur to form fingered
flows. For hydrophobic sandy soils, in contrast, we observe that rain water
ponds on the top of soil surface until the hydraulic pressure is strong enough
to overcome the capillary repellency of soil and create narrow water channels
that penetrate the soil packing. Varying the raindrop impinging speed has
little influence on water channel formation. However, varying the rain rate
causes significant changes in water infiltration depth, water channel width,
and water channel separation. At a fixed raining condition, we combine the
effects of grain diameter and surface hydrophobicity into a single parameter
and determine its influence on water infiltration depth, water channel width,
and water channel separation. We also demonstrate the efficiency of several
soil water improvement methods that relate to rain water channelization
phenomenon, including pre-wetting sandy soils at different level before
rainfall, modifying soil surface flatness, and applying superabsorbent hydrogel
particles as soil modifiers
Observation of a nanophase segregation in LiCl aqueous solutions from Transient Grating Experiments
Transient Grating experiments performed on supercooled LiCl, RH2O solutions
with R>6 reveal the existence of a strong, short time, extra signal which
superposes to the normal signal observed for the R=6 solution and other glass
forming systems. This extra signal shows up below 190 K, its shape and the
associated timescale depend only on temperature, while its intensity increases
with R. We show that the origin of this signal is a phase separation between
clusters with a low solute concentration and the remaining, more concentrated,
solution. Our analysis demonstrates that these clusters have a nanometer size
and a composition which are rather temperature independent, while increasing R
simply increases the number of these clusters.Comment: 19 pages+ 8 figures+ 2 table
Regeneration of the tropical legume Aeschynomene sensitiva Sw. from root explants
Regeneration of #Aeschynomene sensitiva Sw. after callogenesis was obtained form small (2-5 mm long) root explants of 30-day-old seedlings aseptically cultivated on Murashige and Skoog medium supplemented with various concentrations of growth regulators. After 4 weeks, the best results were observed with 0.54 microM alpha-naphthaleneacetic acid and 2.22 microM benzyladenine. On this medium, the rate of regeneration depended on seedling age and agar concentration. The highest number of shoots per explant was obtained with small cuttings from 30-day-old seedlings grown on a medium containing 8 g/l of agar. Regeneration success was also dependent on explant size. When longer explants (7-20 mm) were cut from the main root, direct regeneration was obtained in two weeks. These cuttings also generated shoots through callogenesis in four weeks but always in lower quantities than with direct regeneration, whatever the seedling age. Here also, the best regeneration was obtained with cuttings from 30-day-old seedlings maintained on a medium with 8 g/l of agar. Regenerants were rooted on growth-regulator-free Murashige and Skoog medium and then acclimatized in a greenhouse. A better survival to transplantation was observed when plantlets were inoculated with the photosynthetic #Bradyrhizobium strain ORS 278. Stem and root nodules developed on the inoculated plantlets and were able to fix nitrogen. (Résumé d'auteur
Comparing dynamic correlation lengths from an approximation to the four-point dynamic susceptibility and from the picosecond vibrational dynamics
Recently a new approach to the determination of dynamic correlation lengths,
{\xi}, for supercooled liquids, based on the properties of the slow
(picosecond) vibrational dynamics, was carried out [L. Hong, V.N. Novikov, and
A.P. Sokolov, Phys. Rev. E 83, 061508 (2011)]. Although these vibrational
measurements are typically conducted well below the glass transition
temperature, Tg, the assumption is that the structure of the liquid is frozen
at Tg, so that the {\xi} characterize dynamic heterogeneity in the supercooled
liquid state. We compare {\xi} from this method to values calculated using an
approximation to the four-point dynamic susceptibility. For 26 different
materials we find good correlation between the two measures; moreover, the
pressure dependences are consistent within the large experimental error.
However, {\xi} from Boson peak measurements above Tg have a different, and
unrealistic, temperature dependence.Comment: 10 pages, 3 figure
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