Search results for " Structures"
showing 10 items of 4162 documents
Drifts in real-time partial wavefront correction and how to avoid them
2017
In visual experiments that require real-time partial correction of wavefront aberrations, small errors occur that accumulate over time and lead to drifts in Zernike coefficients of the uncorrected aberrations. A simple algorithm that does not require the inclusion of an additional optical path to obtain independent measurements of the eye's aberrations is described here, and its effectiveness in preventing these drifts is demonstrated.
The tear film and the optical quality of the eye
2010
The stability of the tear film plays an important role in the optical quality of the eye. Various methods have been developed to quantify the contribution of the tear film to optical quality, including the double-pass optical method, Hartmann-Shack wavefront sensing, videokeratoscopy, retroillumination analysis, and interferometry. In addition to assessing the effect of tear film irregularities, these methods can aid in the diagnosis of dry-eye related conditions and the monitoring of therapy. This review describes the methodologies used to assess the relationship between the tear film and optical quality of the eye and summarizes the most important findings obtained with these methods with…
Efficient excitation of dielectric-loaded surface plasmon-polariton waveguide modes at telecommunication wavelengths
2008
International audience; The excitation of surface plasmon-polariton (SPP) waveguide modes in subwavelength dielectric ridges deposited on a thin gold film has been characterized and optimized at telecommunication wavelengths. The experimental data on the electromagnetic mode structure obtained using scanning near-field optical microscopy have been directly compared to full vectorial three-dimensional finite element method simulations. Two excitation geometries have been investigated where SPPs are excited outside or inside the dielectric tapered region adjoint to the waveguide. The dependence of the efficiency of the SPP guided mode excitation on the taper opening angle has been measured an…
Cylindrical metal-coated optical fibre devices for filters and sensors
1996
Novel fibre-optic components suitable for sensor applications and wavelength filters are reported. The devices consist of a tapered fibre whose uniform waist has been coated with a thin layer of gold. The operation principle is the resonant excitation of a surface plasma mode of the metal film.
Study of Photo-Induced Thin Film Growth on Cds Substrates.*
1983
ABSTRACTPhoto-induced growth of ZnS on CdS has been studied using amorphous (thin film) and single-crystal substrates. The effect has been found to occur for light of wavelength shorter than the CdS absorption edge; a maximum light-induced thickness enhancement of 700 Å has been obtained for the ZnS film, with a growth rate of 2000 Å/min. The lightinduced growth, with its observed “memory” of several minutes is consistent with photo-desorption of an adlayer.
Pattern Dystrophy of the Macula in a Case of Steinert Disease
2013
<b><i>Introduction:</i></b> Myotonic dystrophies are typically associated with ocular complications like ptosis, weakness of the ocular muscle and cataracts, but also with less recognized retinal changes. <b><i>Case Report:</i></b> A 41-year-old female with type 1 myotonic dystrophy complained of progressive vision loss. Slit lamp examination revealed the presence of typical bilateral polychromatic cataract with posterior subcapsular component. Dilated fundus examination was remarkable for bilateral macular depigmented changes. Multimodal imaging analysis of the macula suggested the presence of a butterfly-shaped pattern dystrophy. <b>&l…
Architetture lignee per lo spettacolo tra XVII e XVIII secolo a Palermo (Theatral wooden architectures in Palermo during XVIII and XIX centuries)
2016
La realizzazione di architetture per lo spettacolo, stabili o temporanee, interamente realizzate in legno fu una consuetudine sette-ottocentesca diffusa sia in molte grandi città europee sia in centri di minori. Anche a Palermo anfiteatri, teatri-circo e casotti occuparono anche a lungo le piazze del centro storico e grandi edifici "contenitori" pubblici o di facoltosi cittadini, ospitando giochi equestri, spettacoli con animali esotici. La connotazione temporanea suggeriva l'uso del legno a costruttori e progettisti: realizzate rapidamente, potevano con semplicità essere smontate e riproposte altrove. Sebbene si trattasse di "architetture provvisorie", era necessario che fossero non solo s…
The foaming properties of camel and bovine whey: The impact of pH and heat treatment
2018
International audience; he effect of heat treatment (70 degrees C or 90 degrees C for 30 min) on the foaming and interfacial properties of acid and sweet whey obtained from bovine and camel fresh milk was examined. The maximum foamability and foam stability were observed for acid whey when compared to sweet whey for both milks, with higher values for the camel whey. This behavior for acid whey was explained by the proximity of the pI of whey protein (4.9-5.2), where proteins were found to carry the lowest negative charge as confirmed by the zeta potential measurements. Interfacial properties of acid camel whey and acid bovine whey were preserved at air water interface even after a heat trea…
Water vapour permeability, thermal and wetting properties of whey protein isolate based edible films
2010
Abstract This study deals with the effect of whey protein isolate (WPI) and glycerol (GLY) used as a plasticizer on some physical properties of cast whey protein isolate (WPI) films. Films were prepared from heated (80 °C for 30 min) aqueous solutions of WPI at 7, 8, 9 and 10% (w/w), GLY (40%, w/w, of WPI) and WPI at 8% (w/w), GLY (30, 40, and 60%, w/w, of WPI). For all types of films, water vapour permeability for four relative humidity differentials (30–100%, 30–84%, 30–75%, and 30–53%), surface and thermal properties were measured. Varying the proportion of WPI and GLY in edible films had some effect on water vapour permeability, wetting and thermal properties of WPI films. A cumulative …
Lightweight LCP construction for next-generation sequencing datasets
2012
The advent of "next-generation" DNA sequencing (NGS) technologies has meant that collections of hundreds of millions of DNA sequences are now commonplace in bioinformatics. Knowing the longest common prefix array (LCP) of such a collection would facilitate the rapid computation of maximal exact matches, shortest unique substrings and shortest absent words. CPU-efficient algorithms for computing the LCP of a string have been described in the literature, but require the presence in RAM of large data structures. This prevents such methods from being feasible for NGS datasets. In this paper we propose the first lightweight method that simultaneously computes, via sequential scans, the LCP and B…