Results 51 to 60 of about 5,509 (162)

Natural Convection of MHD Double Diffusive Nanoencapsulated Phase Change Material (NEPCM) in the Annulus Between Concentric Horizontal Circular and Square Cylinders

International Journal of Energy Research, Volume 2026, Issue 1, 2026.
The investigation focuses on the natural convection of magnetohydrodynamic (MHD) double‐diffusive nanoencapsulated phase change material (NEPCM) in an annulus composed of square and concentric horizontal circular cylinders. The right, upper, and bottom walls of the outer square cylinder are cooled, while the inner circular cylinder is heated. The NEPCM
Md. Mahadul Islam, Md. Mamun Molla, Preetom Nag, Md. Mahbub Alam, Souhail Souai, Suresh Kannan Balasingam   +5 more
wiley   +1 more source

An Optical Wavefront Sensor Based on a Double Layer Microlens Array

Sensors, 2011
In order to determine light aberrations, Shack-Hartmann optical wavefront sensors make use of microlens arrays (MLA) to divide the incident light into small parts and focus them onto image planes.
Hsiang-Chun Wei, Guo-Dung John Su, Hsin-Ta Hsieh, Vinna Lin   +3 more
doaj   +1 more source

A direct comparison between a MEMS deformable mirror and a liquid crystal spatial light modulator in signal-based wavefront sensing [PDF]

Journal of the European Optical Society-Rapid Publications, 2013
Aberrations degrade the performance of optical systems in terms of resolution and signal-to-noise ratio. This work explores the feasibility of a signal-based wavefront sensor, which employs a search algorithm to estimate Zernike coefficients of given ...
Jewel A. R., Akondi V., Vohnsen B.
doaj   +1 more source

High-resolution imaging and spectroscopy in the visible from large ground-based telescopes with natural guide stars

, 2010
Near-diffraction limited imaging and spectroscopy in the visible on large (8-10 meter) class telescopes has proved to be beyond the capabilities of current adaptive optics technologies, even when using laser guide stars.
King, David, Mackay, Craig, Staley, Tim D., Suess, Frank, Weller, Keith   +4 more
core   +1 more source

Modeling low order aberrations in laser guide star adaptive optics systems [PDF]

, 2007
When using a laser guide star (LGS) adaptive optics (AO) system, quasi-static aberrations are observed between the measured wavefronts from the LGS wavefront sensor (WFS) and the natural guide star (NGS) WFS.
Bouchez, Antonin H., Clare, Richard M., van Dam, Marcos A.   +2 more
core   +1 more source

Retinal Peripheral Defocus and Peripheral Refractive Measurement Techniques: A Review

Journal of Ophthalmology, Volume 2026, Issue 1, 2026.
The theory of retinal peripheral defocus currently represents the prevailing paradigm for myopia prevention and control. Research studies on peripheral refraction indicate that peripheral defocus is significantly associated with the management and progression of myopia.
Lei Chang, Tao Jin, Karuna Sharma
wiley   +1 more source

High-Resolution Imaging in the Visible on Large Ground-Based Telescopes

, 2014
Lucky Imaging combined with a low order adaptive optics system has given the highest resolution images ever taken in the visible or near infrared of faint astronomical objects.
Crass, Jonathan, González-Escélera, Víctor, King, David L., Labadie, Lucas, López, Roberto, Mackay, Craig, Oscoz, Alejandro, Puga, Marta, Pérez-Garrido, Antonio, Pérez-Prieto, Jorge A., Rebolo, Rafael, Rodríguez-Ramos, Luis F., Velasco, Sergio, Villó, Isidro   +13 more
core   +1 more source

Evaluation of Corneal Irregular Astigmatism and Visual Quality Following Bilateral Sequential SMILE and LASEK: A Six‐Year Comparative Study

Journal of Ophthalmology, Volume 2026, Issue 1, 2026.
Purpose To compare the corneal spherical component (SC), regular astigmatism (RA), irregular astigmatism (IA, including asymmetry and irregularity), and visual quality 6 years after small incision lenticule extraction (SMILE) and laser subepithelial keratomileusis (LASEK) for mild‐to‐moderate myopia.
Hua Li, Weinan Hu, Min Li, Yuehui Shi, Lina Sun, Xiaoyun Ma, Jun Zou, Shengjie Li   +7 more
wiley   +1 more source

Adaptive optics design for high-energy kW-class multi-slab laser amplifiers

High Power Laser Science and Engineering
We demonstrate real-time wavefront correction in a high-energy high-average-power DiPOLE100/Bivoj laser using adaptive optics. A bimorph deformable mirror and a Shack–Hartmann wavefront sensor reduced wavefront error 10-fold and improved the Strehl ratio
Tomáš Paliesek, Martin Divoký, Jan Pilař, Martin Smrž, Tomáš Mocek   +4 more
doaj   +1 more source

Fast minimum variance wavefront reconstruction for extremely large telescopes [PDF]

, 2010
We present a new algorithm, FRiM (FRactal Iterative Method), aiming at the reconstruction of the optical wavefront from measurements provided by a wavefront sensor.
Béchet, Ellerbroek, Eric Thiébaut, Fried, Fried, Gendron, Gilles, Gilles, Gilles, Gilles, Herrmann, Lane, Le Louarn, Le Roux, MacMartin, Michel Tallon, Poyneer, Poyneer, Roddier, Skilling, Southwell, Tarantola, Vogel, Vogel, Wild, Yang   +25 more
core   +1 more source