9,724 research outputs found
Boys and Girls in No Man’s Land: English Canadian Children and the First World War (Book Review) by Susan R. Fisher
Individual Expression Versus the Submissive Woman in France
While still in the midst of their study abroad experiences, students at Linfield College write reflective essays. Their essays address issues of cultural similarity and difference, compare lifestyles, mores, norms, and habits between their host countries and home, and examine changes in perceptions about their host countries and the United States. In this essay, Fatima Falcon Ontiveros describes her observations during her study abroad program at the Institut Américain Universitaire in Aix-en-Provence, France
Gravity wave turbulence revealed by horizontal vibrations of the container
We experimentally study the role of the forcing on gravity-capillary wave
turbulence. Previous laboratory experiments using spatially localized forcing
(vibrating blades) have shown that the frequency power-law exponent of the
gravity wave spectrum depends on the forcing parameters. By horizontally
vibrating the whole container, we observe a spectrum exponent that does not
depend on the forcing parameters for both gravity and capillary regimes. This
spatially extended forcing leads to a gravity spectrum exponent in better
agreement with the theory than by using a spatially localized forcing. The role
of the vessel shape has been also studied. Finally, the wave spectrum is found
to scale linearly with the injected power for both regimes whatever the forcing
type used
Simulations of dense granular gases without gravity with impact-velocity-dependent restitution coefficient
We report two-dimensional simulations of strongly vibrated granular materials
without gravity. The coefficient of restitution depends on the impact velocity
between particles by taking into account both the viscoelastic and plastic
deformations of particles, occurring at low and high velocities respectively.
Use of this model of restitution coefficient leads to new unexpected behaviors.
When the number of particles N is large, a loose cluster appears near the fixed
wall, opposite the vibrating wall. The pressure exerted on the walls becomes
independent of N, and linear in the vibration velocity V, quite as the granular
temperature. The collision frequency at the vibrating wall becomes independent
of both N and V, whereas at the fixed wall, it is linear in both N and V. These
behaviors arise because the velocity-dependent restitution coefficient
introduces a new time scale related to the collision velocity near the cross
over from viscoelastic to plastic deformation.Comment: Final version - To be published in Powder Technolog
Alloyed Nanoparticles with Lipid Coatings
Monodisperse silver and gold alloy nanoparticles of controlled composition and size were synthesized for the development of a potential drug delivery system. The seeded growth of the alloy nanoparticles through a co-reduction of gold and silver salts, using the Turkevich approach, was used for synthesizing the nanoparticles. The size of the nanoparticles was characterized using a NanoSight LM10 HS and their composition with a UV-Vis spectrophotometer. These alloys and earlier gold nanoparticles of varying sizes were introduced to live wild-type S. cerevisiae cells in their exponential growth phase, and the absorbance of the cells after incubation with nanoparticles was measured with a UV-Vis spectrophotometer. Absorbance data suggests that the number of nanoparticles taken up by the yeast cells is negligible as no peak was observed in the yeast cells after they had been washed and centrifuged to discard excess alloy nanoparticles. Further research is necessary to see if the addition of antibodies increases the number of nanoparticles attached to the yeast cells, future coating with lipids and a SERS tag, and maybe even attaching a therapeutic agent
Glyph-aware Embedding of Chinese Characters
Given the advantage and recent success of English character-level and
subword-unit models in several NLP tasks, we consider the equivalent modeling
problem for Chinese. Chinese script is logographic and many Chinese logograms
are composed of common substructures that provide semantic, phonetic and
syntactic hints. In this work, we propose to explicitly incorporate the visual
appearance of a character's glyph in its representation, resulting in a novel
glyph-aware embedding of Chinese characters. Being inspired by the success of
convolutional neural networks in computer vision, we use them to incorporate
the spatio-structural patterns of Chinese glyphs as rendered in raw pixels. In
the context of two basic Chinese NLP tasks of language modeling and word
segmentation, the model learns to represent each character's task-relevant
semantic and syntactic information in the character-level embedding.Comment: Workshop on Subword and Character level models in NLP at EMNLP 2017.
Source code availabl
Some aspects of electrical conduction in granular systems of various dimensions
We report on measurements of the electrical conductivity in both a 2D
triangular lattice of metallic beads and in a chain of beads. The
voltage/current characteristics are qualitatively similar in both experiments.
At low applied current, the voltage is found to increase logarithmically in a
good agreement with a model of widely distributed resistances in series. At
high enough current, the voltage saturates due to the local welding of
microcontacts between beads. The frequency dependence of the saturation voltage
gives an estimate of the size of these welded microcontacts. The DC value of
the saturation voltage (~ 0.4 V per contact) gives an indirect measure of the
number of welded contact carrying the current within the 2D lattice. Also, a
new measurement technique provides a map of the current paths within the 2D
lattice of beads. For an isotropic compression of the 2D granular medium, the
current paths are localized in few discrete linear paths. This
quasi-onedimensional nature of the electrical conductivity thus explains the
similarity between the characteristics in the 1D and 2D systems.Comment: To be published in The European Physical Journal
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