Single metallic bowtie nanoantennas provide a controllable environment for surface-enhanced Raman scattering (SERS) of adsorbed molecules. Bowties have experimentally measured electromagnetic enhancements, enabling estimation of chemical enhancement for both the bulk and the few-molecule regime. Strong fluctuations of selected Raman lines imply that a small number of p-mercaptoaniline molecules...

A bowtie is a graph consisting of two triangles with one vertex identified. We show that the class of all (countable) graphs not containing a bowtie as a subgraph have a Ramsey lift (expansion). This is the first non-trivial Ramsey class with a non-trivial algebraic closure. ∗The Computer Science Institute of Charles University (IUUK) is supported by grant ERC-CZ LL-1201 of the Czech Ministry o...

This paper presents a multiband CPW-fed slot antenna with L-slot bowtie tuning stub. The proposed antenna has been designed for PCS 1900, UMTS, WLAN 802.11 a/b/g and bluetooth applications, with a cost-effective FR4 substrate. The proposed antenna still radiate as omni-directional in azimuth plane and sufficient bandwidth for all above mentions. The proposed antenna works as dual-wideband, band...

Nanoscale ridge aperture antennas have been shown to have high transmission efficiency and confined nanoscale radiation in the near field region compared with regularly-shaped apertures. The radiation enhancement is attributed to the fundamental electric-magnetic field propagating in the TE(10) mode concentrated in the gap between the ridges. This paper reports experimental demonstration of fie...

A 4-wheel is a simple graph on 5 vertices with 8 edges, consisting of a 4-cycle, with a fifth vertex joined to each vertex in the 4-cycle. A A-fold 4-wheel system of order n is an edge-disjoint decomposition of AKn into 4-wheels. If two non-adjacent edges of the 4-cycle are removed, the result is a bowtie (that is, two triangles with a common vertex). In this paper necessary and sufficient cond...

ABSTRACT In this paper, we propose a novel method for beam hardening correction in polychromatic transmission tomography. A family of polynomials is firstly determined in a training phase, which forms a complete set in the sense of X-ray physics of medical diagnostic imaging. In particular, every polynomial in the set is indexed by a beam hardening factor, i.e. effective atomic number, which is...

Metallic “bowtie” nanoantennas consisting of two opposing tip-to-tip Au triangles have been fabricated with triangle lengths of 75 nm and gaps ranging from 16 to 488 nm. For light polarized along the line between the two triangles, the plasmon scattering resonance first blueshifts with increasing gap, and then red-shifts as the particles become more and more uncoupled, while perpendicularly pol...