Problems of radiation pattern synthesis, sidelobe suppression, or back suppression appear when using antennas with reflectors ground planes. The use a semitransparent surface allows the required shape to be synthesized efficiently through variation reflection and transmission coefficients. Effective synthesis is possible analytical formulas designed for patterns reflectors. In this article, we ...

Material and methods We have used the Formetric 4D-Dicom II system, which is supplied also with lateral Cobb angle measurement. We have examined 616 patients (432 females and 184 males), age 5 y to 21 y. The patients have been visited clinically by inspection, Adams forward bending test and Perdriolle scoliometer. We have fit, to every patient, 4-8 reflectors on the apex of T1 through L4 spinal...

The confined modes of surface plasmon polaritons in boxing ring-shaped nanocavities have been investigated and imaged by using cathodoluminescence spectroscopy. The mode of the out-of-plane field components of surface plasmon polaritons dominates the experimental mode patterns, indicating that the electron beam locally excites the out-of-plane field component of surface plasmon polaritons. Qual...

We present the design, fabrication and characterization of Bragg reflectors on silicon-on-insulator rib waveguides. The fabrication is based on a new double lithographic process, combining electron-beam lithography for the grating and photolithography for the waveguides. This process allows the realization of low loss reflectors, which were fully characterized. The influence of the etching dept...

We present a novel device based on four orthogonal reflections that displaces an optical beam while preserving the state of polarization. The principle of operation is the overall compensation of the phase shifts that s and p polarization components of the light acquire at each reflection. This compensation, which relies on the use of four identical reflectors, is independent of the actual valu...

Light reflectors are widely used to enhance scintillation light collection. Their enhancement level depends on the reflector’s reflectance at scintillator’s emission wavelength. We report UV–Visible spectra, relative BaSO4, for several common reflectors. Also reported is their radiation hardness against an ionization dose up 100 Mrad. The results of this investigation provide a reference applic...

In this paper we describe changes in spectral reflectivity of the light reflectors (iridophores) of the squid Alloteuthis subulata. The spectral changes that can be seen in living squid, can also be brought about by superfusing whole skin preparations with acetylcholine (ACh) (20 micro mol l(-1)) and muscarine (30 micro mol l(-1)) but not nicotine (up to 50 mmol l(-1)), suggesting that choliner...

On the turn of the twentieth century the refractor was rapidly approaching its limits in terms of aperture. The main reason for this was the difficulty in manufacturing discs of crown and flint glass with diameters greater than 100 cm. Manufactures of plate-glass could however cast large disks of ordinary crown glass, of lower optical quality, that were suitable for mirrors. It was also known t...

Within classical optics, one may add microscopic “roughness” to a macroscopically flat mirror so that parallel rays of a given angle are reflected at different outgoing angles. Taking the limit (as the roughness becomes increasingly microscopic) one obtains a flat surface that reflects randomly, i.e., the transition from incoming to outgoing ray is described by a probability kernel (whose form ...

Influence of the Graded Index Cholesteric Liquid Crystal Reflectors on Luminescent Solar Concentrator Efficiency