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Dynamic behavior and damping capacity of auxetic foam pads
A novel set of auxetic (negative Poisson's ratio) open cell polyurethane foam has been developed and tested under dynamic
loading conditions to assess the viscoelastic response under white noise random excitation and compressive cycling. Foam pads
normalized to standard ISO 13753 have been tested at room temperature and frequency bandwidth 10-500 Hz to assess
transmissibility characteristics for possible antivibration glove applications. The results show that the ISO 13753 normalized
transmissibility for these foams falls below 0.6 above 100 Hz, with lower peak maximum stresses under indentation compared to
conventional open cell solids. These results suggest possible use of the auxetic foam for pads or linens against « white fingers«
vibration applications. Further tests have been conducted on cyclic compressive loading up to 3 Hz and loading ratios of 0.95 for
loading histories up to 100000 cycles. The damping capacity of the auxetic foams showed and increase by a factor 10 compared
to the conventional foams used to manufacture the negative Poisson's ratio ones, and stiffness degradation stabilized after few tens on cycles
Complications associated with introduction of new neuraxial equipment
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86882/1/j.1365-2044.2011.06742.x.pd
Transfer device for supermorbidly obese patients
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71881/1/j.1365-2044.2007.05388.x.pd
Josephson junctions with negative second harmonic in the current-phase relation: properties of novel varphi-junctions
Several recent experiments revealed a change of the sign of the first
harmonic in the current-phase relation of Josephson junctions (JJ) based on
novel superconductors, e.g., d-wave based or JJ with ferromagnetic barrier. In
this situation the role of the second harmonic becomes dominant and it
determines the scenario of a 0-pi transition. We discuss different mechanisms
of the second harmonic generation and its sign. If the second harmonic is
negative the 0-pi transition becomes continuous and the realization of the
so-called varphi junction is possible. We study the unusual properties of such
a novel JJ and analyze the possible experimental techniques for their
observation.Comment: submitted to PR
Characterization of the spore surface and exosporium proteins of Clostridium sporogenes; implications for Clostridium botulinum group I strains.
Clostridium sporogenes is a non-pathogenic close relative and surrogate for Group I (proteolytic) neurotoxin-producing Clostridium botulinum strains. The exosporium, the sac-like outermost layer of spores of these species, is likely to contribute to adhesion, dissemination, and virulence. A paracrystalline array, hairy nap, and several appendages were detected in the exosporium of C. sporogenes strain NCIMB 701792 by EM and AFM. The protein composition of purified exosporium was explored by LC-MS/MS of tryptic peptides from major individual SDS-PAGE-separated protein bands, and from bulk exosporium. Two high molecular weight protein bands both contained the same protein with a collagen-like repeat domain, the probable constituent of the hairy nap, as well as cysteine-rich proteins CsxA and CsxB. A third cysteine-rich protein (CsxC) was also identified. These three proteins are also encoded in C. botulinum Prevot 594, and homologues (75-100% amino acid identity) are encoded in many other Group I strains. This work provides the first insight into the likely composition and organization of the exosporium of Group I C. botulinum spores
Time-Dependent Symmetries of Variable-Coefficient Evolution Equations and Graded Lie Algebras
Polynomial-in-time dependent symmetries are analysed for polynomial-in-time
dependent evolution equations. Graded Lie algebras, especially Virasoro
algebras, are used to construct nonlinear variable-coefficient evolution
equations, both in 1+1 dimensions and in 2+1 dimensions, which possess
higher-degree polynomial-in-time dependent symmetries. The theory also provides
a kind of new realisation of graded Lie algebras. Some illustrative examples
are given.Comment: 11 pages, latex, to appear in J. Phys. A: Math. Ge
Propagation and interaction of ultrashort electromagnetic pulses in nonlinear media with a quadratic-cubic nonlinearity
Propagation of extremely short unipolar pulses of electromagnetic field
("videopulses") is considered in the framework of a model in which the material
medium is represented by anharmonic oscillators (approximating bound electrons)
with quadratic and cubic nonlinearities. Two families of exact analytical
solutions (with positive or negative polarity) are found for the moving
solitary pulses. Direct simulations demonstrate that the pulses are very robust
against perturbations. Two unipolar pulses collide nearly elastically, while
collisions between pulses with opposite polarities and a small relative
velocity are inelastic, leading to emission of radiation and generation of a
small-amplitude additional pulse.Comment: 12 pages, 10 figure
Performance evaluation of novel square-bordered position-sensitive silicon detectors with four-corner readout
We report on a recently developed novel type of large area (62 mm x 62 mm)
position sensitive silicon detector with four-corner readout. It consists of a
square-shaped ion-implanted resistive anode framed by additional
low-resistivity strips with resistances smaller than the anode surface
resistance by a factor of 2. The detector position linearity, position
resolution, and energy resolution were measured with alpha-particles and heavy
ions. In-beam experimental results reveal a position resolution below 1 mm
(FWHM) and a very good non-linearity of less than 1% (rms). The energy
resolution determined from 228Th alpha source measurements is around 2% (FWHM).Comment: 13 pages, 10 figures, submitted to Nucl. Instr. and Meth.
Invariant solutions of the supersymmetric sine-Gordon equation
A comprehensive symmetry analysis of the N=1 supersymmetric sine-Gordon
equation is performed. Two different forms of the supersymmetric system are
considered. We begin by studying a system of partial differential equations
corresponding to the coefficients of the various powers of the anticommuting
independent variables. Next, we consider the super-sine-Gordon equation
expressed in terms of a bosonic superfield involving anticommuting independent
variables.
In each case, a Lie (super)algebra of symmetries is determined and a
classification of all subgroups having generic orbits of codimension 1 in the
space of independent variables is performed. The method of symmetry reduction
is systematically applied in order to derive invariant solutions of the
supersymmetric model. Several types of algebraic, hyperbolic and doubly
periodic solutions are obtained in explicit form.Comment: 27 pages, major revision, the published versio
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