4,906 research outputs found

    Cluster glasses of ultrasoft particles

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    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

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    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

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    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

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    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

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    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

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    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

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    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

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    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

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    We use confocal microscopy to study the motion of a magnetic bead in a dense colloidal suspension, near the colloidal glass transition volume fraction ϕg\phi_g. For dense liquid-like samples near ϕg\phi_g, 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 ϕg\phi_g 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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