4,848 research outputs found
Cluster glasses of ultrasoft particles
We present molecular dynamics (MD) simulations results for dense fluids of
ultrasoft, fully-penetrable particles. These are a binary mixture and a
polydisperse system of particles interacting via the generalized exponential
model, which is known to yield cluster crystal phases for the corresponding
monodisperse systems. Because of the dispersity in the particle size, the
systems investigated in this work do not crystallize and form disordered
cluster phases. The clustering transition appears as a smooth crossover to a
regime in which particles are mostly located in clusters, isolated particles
being infrequent. The analysis of the internal cluster structure reveals
microsegregation of the big and small particles, with a strong
homo-coordination in the binary mixture. Upon further lowering the temperature
below the clustering transition, the motion of the clusters' centers-of-mass
slows down dramatically, giving way to a cluster glass transition. In the
cluster glass, the diffusivities remain finite and display an activated
temperature dependence, indicating that relaxation in the cluster glass occurs
via particle hopping in a nearly arrested matrix of clusters. Finally we
discuss the influence of the microscopic dynamics on the transport properties
by comparing the MD results with Monte Carlo simulations.Comment: 17 pages, 23 figure
Ultra-Stretchable Interconnects for High-Density Stretchable Electronics
The exciting field of stretchable electronics (SE) promises numerous novel
applications, particularly in-body and medical diagnostics devices. However,
future advanced SE miniature devices will require high-density, extremely
stretchable interconnects with micron-scale footprints, which calls for proven
standardized (complementary metal-oxide semiconductor (CMOS)-type) process
recipes using bulk integrated circuit (IC) microfabrication tools and
fine-pitch photolithography patterning. Here, we address this combined
challenge of microfabrication with extreme stretchability for high-density SE
devices by introducing CMOS-enabled, free-standing, miniaturized interconnect
structures that fully exploit their 3D kinematic freedom through an interplay
of buckling, torsion, and bending to maximize stretchability. Integration with
standard CMOS-type batch processing is assured by utilizing the Flex-to-Rigid
(F2R) post-processing technology to make the back-end-of-line interconnect
structures free-standing, thus enabling the routine microfabrication of
highly-stretchable interconnects. The performance and reproducibility of these
free-standing structures is promising: an elastic stretch beyond 2000% and
ultimate (plastic) stretch beyond 3000%, with 10
million cycles at 1000% stretch with <1% resistance change. This generic
technology provides a new route to exciting highly-stretchable miniature
devices.Comment: 13 pages, 5 figure, journal publicatio
Power Spectra in a Zero-Range Process on a Ring: Total Occupation Number in a Segment
We study the dynamics of density fluctuations in the steady state of a
non-equilibrium system, the Zero-Range Process on a ring lattice. Measuring the
time series of the total number of particles in a \emph{segment} of the
lattice, we find remarkable structures in the associated power spectra, namely,
two distinct components of damped-oscillations. The essential origin of both
components is shown in a simple pedagogical model. Using a more sophisticated
theory, with an effective drift-diffusion equation governing the stochastic
evolution of the local particle density, we provide reasonably good fits to the
simulation results. The effects of altering various parameters are explored in
detail. Avenues for improving this theory and deeper understanding of the role
of particle interactions are indicated.Comment: 21 pages, 15 figure
Patterson Function from Low-Energy Electron Diffraction Measured Intensities and Structural Discrimination
Surface Patterson Functions have been derived by direct inversion of
experimental Low-Energy Electron Diffraction I-V spectra measured at multiple
incident angles. The direct inversion is computationally simple and can be used
to discriminate between different structural models. 1x1 YSi_2 epitaxial layers
grown on Si(111) have been used to illustrate the analysis. We introduce a
suitable R-factor for the Patterson Function to make the structural
discrimination as objective as possible. From six competing models needed to
complete the geometrical search, four could easily be discarded, achieving a
very significant and useful reduction in the parameter space to be explored by
standard dynamical LEED methods. The amount and quality of data needed for this
analysis is discussed.Comment: 5 pages, 4 figure
Forensic Anthropology Case Team
IMPACT. 1: FACT offers scientific expertise in archeological field methods and osteological laboratory methods to the community to help resolve medicolegal death investigations, at no charge. -- 2. Since 2010, FACT has been involved in over 25 prehistoric, historic, and modern investigations involving human and non-human remains. -- 3. FACT provides team members with opportunities for professional development, improving leadership and transdisciplinary team-based skills, and applying advanced training in anthropology, anatomy, and statistics received from OSU.OSU PARTNERS: Department of Anthropology; Department of Public Safety; Division of AnatomyCOMMUNITY PARTNERS: Academy of Pharmacy of Central Ohio; Belmont County Sherriff's Office; Clark County Coroner's Office; Clark County Sherriff's Office; Columbus Police Department; Franklin County Coroner's Office; K9 Response Search and Rescue; Lima Police Department; Mansfield Police Department; Mount Tabor Cemetery Association; Ohio Bureau of Criminal Investigation and Identification; Ohio State Chapter of Sigma Xi; Ohio Valley Archaeology, Inc.; PAST Innovation Lab; Perry County Sherriff's Office; Powell Police Department; Search and Rescue Ohio; Six River Valley Chapter of the Archaeological Society of Ohio; Upper Arlington Citizen; Police Academy; Village of Fort Jennings, OH; Westerville Police DepartmentPRIMARY CONTACT: Timothy P. Gocha ([email protected]); Samuel D. Stout ([email protected]); Jules R. Angel (angel.29@edu)FACT serves the Ohio community by assisting government agencies search for, recover, and identify human remains. The team comprises faculty and graduate students possessing a high level of scientific competence and ethical standing while promoting the highest quality of professional and personal conduct. FACT facilitates training programs for medicolegal, law enforcement, and search and rescue professionals. The team engages in outreach to dispel myths about forensic science and mentors students interested in forensic science
Quantum simulation of Anderson and Kondo lattices with superconducting qubits
We introduce a mapping between a variety of superconducting circuits and a
family of Hamiltonians describing localized magnetic impurities interacting
with conduction bands. This includes the Anderson model, the single impurity
one- and two-channel Kondo problem, as well as the 1D Kondo lattice. We compare
the requirements for performing quantum simulations using the proposed circuits
to those of universal quantum computation with superconducting qubits, singling
out the specific challenges that will have to be addressed.Comment: Longer versio
Electron electric dipole moment experiment using electric-field quantized slow cesium atoms
A proof-of-principle electron electric dipole moment (e-EDM) experiment using
slow cesium atoms, nulled magnetic fields, and electric field quantization has
been performed. With the ambient magnetic fields seen by the atoms reduced to
less than 200 pT, an electric field of 6 MV/m lifts the degeneracy between
states of unequal mF and, along with the low (approximately 3 m/s) velocity,
suppresses the systematic effect from the motional magnetic field. The low
velocity and small residual magnetic field have made it possible to induce
transitions between states and to perform state preparation, analysis, and
detection in regions free of applied static magnetic and electric fields. This
experiment demonstrates techniques that may be used to improve the e-EDM limit
by two orders of magnitude, but it is not in itself a sensitive e-EDM search,
mostly due to limitations of the laser system.Comment: 9 pages, 8 figures, accepted for publication in Phys. Rev.
FORMULATION AND EVALUATION OF FLOATING ORAL IN SITU GEL OF DILTIAZEM HYDROCHLORIDE
Objective: The objective of the present study was to formulate and evaluate the floating in-situ gelling system of diltiazem hydrochloride.Methods: Sodium alginate based diltiazem hydrochloride floating in situ gelling systems were prepared by dissolving hydroxyl propyl methyl cellulose (HPMC) in 25% of water, to which calcium carbonate and diltiazem hydrochloride were added with stirring to form, a proper and a homogenous dispersion of diltiazem hydrochloride. Meanwhile, 30% of water was heated to 60 ËšC on a hot plate to dissolve sodium alginate and cooled to 40 ËšC. The resulting solution was added to HPMC solution and mixed well. To 5% of water at 60 ËšC, sodium methyl paraben was added and dissolved and cooled to 40 ËšC and was added to the above mixture and mixed well. The volume was adjusted finally to 100% with distilled water. Prepared formulae were evaluated for physicochemical properties, drug content, pH, in vitro gelling capacity, in vitro buoyancy, viscosity, water uptake and in vitro drug release.Results: Formulation variables such as type and concentration of viscosity enhancing polymer (sodium alginate) and HPMC affected the formulation viscosity, gelling properties, floating behavior, and in vitro drug release. Formulation F5 and F6 showed the floating time of 5 min and more than 20 h respectively. A significant decrease in the rate and extent of the drug release was observed with the increase in polymer concentration in in-situ gelling preparation. Formulation F4, F5, F6 were shown to have extended drug release until the end of 7 h.Conclusion: The prepared in situ gelling formulations of diltiazem hydrochloride could float in the gastric conditions and released the drug in a sustained manner. The present formulation was non-irritant, easy to administer along with good retention properties, better patient compliant and with greater efficacy of the drug
Forced motion of a probe particle near the colloidal glass transition
We use confocal microscopy to study the motion of a magnetic bead in a dense
colloidal suspension, near the colloidal glass transition volume fraction
. For dense liquid-like samples near , below a threshold force
the magnetic bead exhibits only localized caged motion. Above this force, the
bead is pulled with a fluctuating velocity. The relationship between force and
velocity becomes increasingly nonlinear as is approached. The
threshold force and nonlinear drag force vary strongly with the volume
fraction, while the velocity fluctuations do not change near the transition.Comment: 7 pages, 4 figures revised version, accepted for publication in
Europhysics Letter
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