Objective. To evaluate the degree of axial elongation with soft radial refractive gradient (SRRG) contact lenses, orthokeratology (OK), and single vision (SV) spectacle lenses (control) during a period 1 year before treatment 2 years after treatment. Methods. This was prospective, longitudinal, nonrandomized study. The study groups consisted 30, 29, 41 children, respectively. length (AL) measured recruitment lens fitting. Results. baseline sphere correlated significantly (Spearman’s Rho ( ρ...

To assess the optical performance of four extended range vision (ERV) intraocular lenses (IOLs) and predict visual quality average pseudophakic patient.Four ERV IOLs (LuxSmart, Bausch & Lomb; Vivity, Alcon Laboratories, Inc; Tecnis Eyhance, Johnson Vision; Isopure, PhysIOL) were inserted in an on-bench model eye. Their was assessed using through-focus modulation transfer function (MTF)-based metrics, point spread function, halo analysis for three pupils (2.0, 3.0, 4.5 mm). The expected...

We study the feasibility of femtosecond laser writing optical waveguides in bulk 35PbO∙35Bi2O3∙15Ga2O3∙15GeO2 glass, motivated by extended transparency interval heavy metal oxide glasses mid-infrared regime. Its large linear and nonlinear refractive indices cause critical self-focusing to occur even at low energies, leading filamentary propagation material damage. However, vicinity laser-damaged region shows a considerable increase index, which we attribute collateral, stress-induced...

To evaluate changes in the peripheral refraction (PR), visual quality, and accommodative lag with a novel soft radial refractive gradient (SRRG) experimental contact lens that produces myopic defocus.59 right eyes were fitted lens. The PR was measured up to 30° nasal temporal horizontal fields compared values obtained without monocularly using distance-induced condition method at 40 cm, higher-order aberrations (HOAs) of entire eye for 3- 5-mm pupils by aberrometry. Visual performance...

This article studies the relationship between two metrics, area under modulation transfer function (MTFa) and energy efficiency (EE), their ability to predict visual quality of patients implanted with multifocal intraocular lenses (IOLs). The optical IOLs is assessed in vitro using MTFa EE. We measured them for three different parabolic phase profile image formation, through-focus (TF) scanning, R, G, B wavelengths, pupils. analyzed correlation In parallel, clinical defocus curves acuity...

It is shown that optical surfaces traditionally ground in conventional glasses with high coefficients of thermal expansion may be polished by irradiation a space- and time-controlled uniform CO(2) laser beam. Comparisons theoretical simulation model the laser-driven heating process experimental results allow us to determine conditions for successful reliable use this technique. The technique can applied indiscriminately preheated samples made different glasses, any topography, and, size...

We report on the mechanisms responsible for formation of optical waveguides upon femtosecond laser irradiation an alkaline lead-oxide silicate glass. MicroRaman spectroscopy and nonlinear fluorescence were employed to probe local glass network structure optically active defects respectively. At low pulse energies, modified region is formed by a single light guiding region, whereas pulses above 14 μJ central dark zone, which does not guide light, accompanied zones located in surrounding one....

In this work, a new approach to experimental study of cutting forces and heating in milling is carried out. Work done without cooling, over type AISI 316L austenitic stainless steel, comparison between up-milling down-milling performed. Maximum values force (Fc), resultant (R) or maximum temperature (Tmax) are used obtain qualitative quantitative analyses. The results show that major influencing determinant not the instant undeformed chip thickness. This significant if orthogonal turning...

This study aims to detect alterations in the spatio-chromatic pseudophakic vision produced by multifocal diffractive intraocular lenses (IOLs) and provides a physical interpretation.In vitro characterization of imaging performance two IOLs: AT LISA Tri (Zeiss) FineVision (PhysIOL) on-bench model eye illuminated with red (R, 625 nm), green (G, 530 nm) blue (B, 455 lights. We used metrics: energy efficiency (EE), area under modulation transfer function, longitudinal chromatic aberration (LCA),...

The strong wavelength dependency of diffractive elements casts reasonable doubts on the reliability near-infrared- (NIR)-based clinical instruments, such as aberrometers and double-pass systems, for assessing, post-surgery, visual quality eyes implanted with multifocal intraocular lenses (DMIOLs). results obtained patients when using NIR light can be misleading. Ordinary compensation refractive error bound to chromatic aberration is not enough because it only considers best focus shift but...

Abstract This paper describes a model for the analysis of quality teaching and learning in higher education. Empirically validated through an extensive student‐focused survey, this puts forward concept that challenges which is commonly used institutional analysis. Research indicates quality, rather than being simple technical outcome, construction responding to principle situated action, different well‐aligned functions exist within certain settings contexts. The ELQ/AQA08 proves valuable...

<p><span style="font-family: Arial; font-size: x-small;">Las cuatro experiencias que presentamos en este artículo utilizan el portafolio como método para ayudar al estudiante aprendizaje de conocimientos y competencias transversales. En tres ellas se integra un elemento ayuda a organizar su trabajo la asignatura, reflexionar sobre valorar sus resultados. El también presenta instrumento evaluación sumativa formativa. última experiencia tiene objetivo ofrecer oportunidad grado...

This work describes the phase transitions occurring at film-substrate interface of amorphous germanium films upon nanosecond laser-pulse-induced melting surface. Films with thickness ranging from 50 to 130 nm deposited on glass substrates were studied. Real-time reflectivity measurements subnanosecond time resolution performed both air-film and interfaces used obtain surface in-depth information process. In thicker (⩾80nm), enthalpy released solidification a shallow molten layer induces thin...

<p><span style="font-family: Arial; font-size: x-small;">Preguntarse por la calidad del aprendizaje en Educación Superior (E.S.) no es una cuestión nada simple. Como toda apreciación de naturaleza evaluadora, fundamentalmente depende los referentes empleados hacerlo y modo cómo se realiza. Ello convierte a dicha noción un concepto complejo controvertido debido las distintas aproximaciones posibles sobre el mismo. Por lo tanto, preguntarse acerca "qué calidad" "para quién" punto...

Algorithmic State Machines are a 40-year old tool for the design of digital circuits. They good alternative to finite state machines, where only states can be properly described, but actions must annotated as lateral comments. However, current notation these diagrams has several limitations medium-large designs, and often annotations finally needed. This paper presents an ASM diagrams, trying overcome limitations. new is more consistent thus convenient CAD tools.

Rapid solidification dynamics in amorphous germanium films melted by nanosecond laser pulses has been analyzed means of single-shot subnanosecond time resolved reflectivity measurements using a streak camera based setup. The results show that once minimum melt depth is induced, bulk process followed the release enthalpy dominates scenario. Moreover, laser-melted material solidifies completely before being remelted as consequence release, something only observed, up to date, upon irradiation...

An analysis is given of how nonuniformities in the laser beam intensity translate into variations on induced temperature distribution an irradiated sample. The study involves materials with different thermal conductivities. By use a reshaped irradiating obtained multifaceted integrating mirror, three-dimensional numerical calculation allows us to establish both surface and in-depth distributions. results show that case such as glass (i.e., low conductivity) large gradients occur depth during...

Laser heating of glass samples is a simple and versatile method for obtaining polished surfaces optical quality. Since laser beam intensity non-uniformity can translate into significant variations in the induced surface temperature, success surface-polishing process strongly depends on uniform profiles or flat-top distributions at sample plane. In this paper we present comparison between large-area CO<SUB>2</SUB> laser-polishing experiments carried out substrates following two different...

A new integration method suited for spatially coherent high-power laser beams is demonstrated. The integrator system based on a mirror with two facets, one of which can vibrate under the action piezoelectric translator. After reflection in faceted mirror, beam intensity distribution modified to obtain greater uniformity. However, because coherence reflected beamlets, this affected by an interference pattern. active consists periodic displacement moving facet that causes pattern vibrate, and...

Heavy metal oxide (HMO) glasses include, among others, compound with high Bi- and/or Pb-oxide content. These materials are very atttractive for photonic applications because they show phonon energies lower than those of silicates or borates, which provides them an extended transparency interval in the mid infrared (&#955; &le; 7-8 &#956;m). This feature makes specially suitable transmission applications. In addition, have density, a relatively low glass transition temperature, and excellent...

This paper reports the latest advances achieved in ASM++ methodology since its presentation FPGAworld Conference 2007 and 2008. A fully new compiler has been built, with an improved graphical interface, but also implementing a hierarchical compilation. It allows easy behavioral description of very low level digital designs at register transfer (a dual port RAM memory, for example), it can manage complex structural easily reusable components small System-on-a-Chip example developed USB...

ResumenEste artículo muestra la estrecha relación que existe entre los diagramas de estado algorítmicos (ASM charts) y modernos lenguajes descripción circuitos, ambos empleados en el diseño circuitos digitales.Se proponen sustanciales mejoras sobre notación actual con objetivo desarrollar un compilador capaz procesar automáticamente estos generar código VHDL o Verilog correspondiente.El uso esta metodología facilita aprendizaje del digitales a nivel transferencia registros (RTL).El lenguaje...