12,626 research outputs found
Drip and Mate Operations Acting in Test Tube Systems and Tissue-like P systems
The operations drip and mate considered in (mem)brane computing resemble the
operations cut and recombination well known from DNA computing. We here
consider sets of vesicles with multisets of objects on their outside membrane
interacting by drip and mate in two different setups: in test tube systems, the
vesicles may pass from one tube to another one provided they fulfill specific
constraints; in tissue-like P systems, the vesicles are immediately passed to
specified cells after having undergone a drip or mate operation. In both
variants, computational completeness can be obtained, yet with different
constraints for the drip and mate operations
Improved zinc oxide thermal control coatings
Ferricyanide/ferrocyanide couple prevents zinc oxide pigment degradation in thermal control coatings. Chemical couple retards physical optical property changes
Priorities, Promoters and Inhibitors in Deterministic Non-Cooperative P Systems
Membrane systems (with symbol objects) are distributed controlled multiset
processing systems. Non-cooperative P systems with either promoters or inhibitors (of
weight not restricted to one) are known to be computationally complete. Since recently,
it is known that the power of the deterministic subclass of such systems is subregular. We
present new results on the weight of promoters and inhibitors, as well as for characterizing
the systems with priorities only
Low-energy diffraction; a direct-channel point of view: the background
We argue that at low-energies, typical of the resonance region, the
contribution from direct-channel exotic trajectories replaces the Pomeron
exchange, typical of high energies. A dual model realizing this idea is
suggested. While at high energies it matches the Regge pole behavior, dominated
by a Pomeron exchange, at low energies it produces a smooth, structureless
behavior of the total cross section determined by a direct-channel nonlinear
exotic trajectory, dual to the Pomeron exchange.Comment: 6 pages, 1 figure. Talk presented at the Second International
"Cetraro" Workshop & NATO Advanced Research Workshop "Diffraction 2002",
Alushta, Crimea, Ukraine, August 31 - September 6, 200
Ultrasonic Doppler measurement of renal artery blood flow
An extensive evaluation of the practical and theoretical limitations encountered in the use of totally implantable CW Doppler flowmeters is provided. Theoretical analyses, computer models, in-vitro and in-vivo calibration studies describe the sources and magnitudes of potential errors in the measurement of blood flow through the renal artery, as well as larger vessels in the circulatory system. The evaluation of new flowmeter/transducer systems and their use in physiological investigations is reported
Effect of environment on thermal control coatings
Ferrocyanide and ferricyanide additives for prevention of optical degradation of coatings by ultraviolet radiation and vacuu
Dislocation plasticity in thin metal films
This article describes the current level of understanding of dislocation plasticity in thin
films and small structures in which the film or structure dimension plays an important
role. Experimental observations of the deformation behavior of thin films, including
mechanical testing as well as electron microscopy studies, will be discussed in light of
theoretical models and dislocation simulations. In particular, the potential of applying
strain-gradient plasticity theory to thin-film deformation is discussed. Although the
results of all studies presented follow a “smaller is stronger” trend, a clear functional
dependence has not yet been established
Equilibrium orbit analysis in a free-electron laser with a coaxial wiggler
An analysis of single-electron orbits in combined coaxial wiggler and axial
guide magnetic fields is presented. Solutions of the equations of motion are
developed in a form convenient for computing orbital velocity components and
trajectories in the radially dependent wiggler. Simple analytical solutions are
obtained in the radially-uniform-wiggler approximation and a formula for the
derivative of the axial velocity with respect to Lorentz factor
is derived. Results of numerical computations are presented and the
characteristics of the equilibrium orbits are discussed. The third spatial
harmonic of the coaxial wiggler field gives rise to group orbits which
are characterized by a strong negative mass regime.Comment: 13 pages, 9 figures, to appear in phys. rev.
The DVCS Measurement at HERA
The recent results of the studies of Deeply Virtual Compton Scattering (DVCS)
events at HERA are presented. The possibility offered by this process to gain
information about skewed parton distributions (SPD) is emphasized.Comment: Talk given at New Trends in HERA Physics 2001, Ringberg Castle,
Tegernsee, Germany, 17-22 Jun 2001, 13 pages, 10 figures, recent ZEUS data
discussed, references update
Ultrasonic Doppler measurement of renal artery blood flow
Studies were made of (1) blood flow redistribution during lower body negative pressure (LBNP), (2) the profile of blood flow across the mitral annulus of the heart (both perpendicular and parallel to the commissures), (3) testing and evaluation of a number of pulsed Doppler systems, (4) acute calibration of perivascular Doppler transducers, (5) redesign of the mitral flow transducers to improve reliability and ease of construction, and (6) a frequency offset generator designed for use in distinguishing forward and reverse components of blood flow by producing frequencies above and below the offset frequency. Finally methodology was developed and initial results were obtained from a computer analysis of time-varying Doppler spectra
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