We demonstrate a significant reduction in the limit of label-free detection of individual viral-sized nanoparticles in aqueous solution through the use of a frequency doubled telecom laser constructed from a distributed feedback-periodically poled lithium-niobate (DFB-PPLN) union. By driving a whispering gallery mode biosensor near a wavelength of 650 nm with this device we have detected real-t...

We report microsecond timescale molecular dynamics simulation of the complex formed between Pt(II)-phenanthroline and the 16 N-terminal residues of the Aβ peptide that is implicated in the onset of Alzheimer's disease, along with equivalent simulations of the metal-free peptide. Simulations from a variety of starting points reach equilibrium within 100 ns, as judged by root mean square deviatio...

We find that curvature-driven growth of pores in electrically charged membranes correctly reproduces charge-pulse experiments. Our model, consisting of a Langevin equation for the time dependence of the pore radius coupled to an ordinary differential equation for the number of pores, captures the statistics of the pore population and its effect on the membrane conductance. The calculated pore r...

Stamping simulations usually make the plane stress simplifying assumption. However, this becomes less valid when material draws around features with radius to sheet thickness ratios less than 20. Pereira, Yan & Rolfe (Wear, Vol.265, p.1687 (2008)) predicted that out-of-plane stress equivalent to material yield can occur because a line contact forms briefly at the start of the draw process. The ...

Abstrac tAn in-situ procedure for calibrating the equivalent radius and width of the coil transducer in rotating mode measurements for magnetic field quality analysis is proposed. The standard calibration procedure is not suitable when the coil is longer than the magnet under test, because an average value of the radius and of the width along the length as a whole is obtained. This problem incr...

Perfect weighted coverings of radius one have been often studied in the Hamming metric. In this paper, we study these codes in the Lee metric. To simplify the notation, we use a slightly different description, yet equivalent. Given two integers a and b , an (a, b)-code is a set of vertices such that vertices in the code have a neighbours in the code and other vertices have b neighbours in the c...

We consider the Tree Augmentation problem: given a graph G = (V,E) with edge-costs and a tree T on V disjoint to E, find a minimum-cost edge-subset F ⊆ E such that T ∪ F is 2-edge-connected. Tree Augmentation is equivalent to the problem of finding a minimumcost edge-cover F ⊆ E of a laminar set-family. The best known approximation ratio for Tree Augmentation is 2, even for trees of radius 2. A...

Determination of the regularity radius r∗ of interval matrices is known to be a NP-hard problem. In this paper, a method for determining r∗ is suggested whose numerical complexity is not a priori exponential. The method is based on an equivalent transformation of the original problem to the problem of determining the real maximum magnitude eigenvalue μ∗ of an associated interval generalized eig...

A reiterative technique is developed for finding in normalized form the differential phase shift provided by the circular waveguide, completely filled with azimuthally magnetized ferrite which propagates normal TE01 mode. It consists in a repeated numerical solution of the structure’s characteristic equation, derived in terms of a definite complex Kummer confluent hypergeometric function, follo...

In the present work, we investigate the minimum wear depth of single crystalline Cu(111) under single asperity friction by means of molecular dynamics simulations. The atomistic mechanisms governing the incipient plasticity are elucidated by characterizing specific defect structures and are correlated to the observed mechanical and frictional responses of the material. Furthermore, the effect o...