A model for a proton collecting apparatus on a protein surface includes a ring-shaped collecting domain on which reversible receptors are scattered. These transport a proton by surface diffusion, until it reaches a central orifice where it is absorbed. Mathematically, this scenario is represented approximately by twodimensional diffusion on the ring, with steady-state rate coefficients for adso...

Switching of intramolecular energy transfer is a challenging subject [ l-3 1. The problem is: is it possible to use a photochromic molecule F as central part of a supermolecule D-F-A to allow or to hinder energy transfer from D (donor) to A (acceptor) by switching F with light of the appropriate wavelength from one of its photochromic configurations into the other one and back? Promising candid...

PURPOSE To assess the outcome of Ferrara intracorneal ring segments for keratoconus. SETTING Private practice and university hospital, Porto Alegre, Brazil. METHODS In this retrospective noncomparative interventional case series, 51 keratoconus eyes of 47 patients that had Ferrara intracorneal ring segment implantation were reviewed. Uncorrected visual acuity (UCVA), best spectacle-correcte...

M06-2X/6-31+G(d,p) computations are reported for the 8π-6π electrocyclization cascades of 1,3,5,7-tetraenes. The rate-determining step for these cascades is typically the second (6π) ring closure. According to experiment and theory, un- and monosubstituted tetraenes readily undergo 8π electrocyclic ring closure to form 1,3,5-cyclooctatrienes; however, the 6π electrocyclizations of these cyclooc...

in this paper, we introduce the new notion of strongly j-clean rings associatedwith polynomial identity g(x) = 0, as a generalization of strongly j-clean rings. we denotestrongly j-clean rings associated with polynomial identity g(x) = 0 by strongly g(x)-j-cleanrings. next, we investigate some properties of strongly g(x)-j-clean.

Quantum-dot Cellular Automata (QCA) is an emerging and promising technology that provides significant improvements over CMOS. Recently QCA has been advocated as an applicant for implementing reversible circuits. However QCA, like other Nanotechnologies, suffers from a high fault rate. The main purpose of this paper is to develop a fault tolerant model of QCA circuits by redundancy in hardware a...

We investigate parallelizable schemes for simulating dynamics of conservative systems admitting a decomposition into weakly coupled subsystems. A new method, related to Reversible Averaging [20], is introduced for constrained and unconstrained dynamics. Stability issues are discussed.

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