Search results for "Lens"
showing 10 items of 948 documents
Sensibilidad al contraste tras cirugía de cristalino transparente con lente intraocular multifocal asférica difractiva
2013
PURPOSE: To evaluate distance and near contrast sensitivity (CS) under photopic and mesopic conditions before and after refractive lens exchange (RLE) and implantation of the aspheric AcrySof®ReSTOR® (SN6AD3 model) intraocular lens (IOL). METHODS:Seventy-four eyes of 37 patients after RLE underwent bilateral implantation with the aspheric AcrySof ReSTOR IOL. The patient sample was divided into myopic and hyperopic groups. Monocular uncorrected visual acuity at distance and near (UCVA and UCNVA, respectively) and monocular best corrected visual acuity at distance and near (BCVA and BCNVA, respectively) were measured before and 6 months postoperatively. Monocular CS function was measured at t…
Some topological properties of the Inverse Lens Mapping
2011
Away from critical curves, lens mapping can be seen as a linear invertible transformation of the plane even for regions (cells) of relatively large size. However, close to critical curves the departures from linearity can be very strong. We discuss the topological problems induced by the mapping of regions of the image plane that include critical curves (critical cells).
Cultivation of Dill (Anethum graveolens L.) with Different Row Arrangements
2011
Dill (Anethum graveolens L.) is an annual plant from the Umbelliferae. Although in cookery also sprouts and tender leaves are used, the drug from dill is represented by the scented fruits (“seeds”), largely used for flavouring conserved foods and liqueurs, but also by the herbal and cosmetic industry. In this work, we present the results of a trial performed in Sicily, putting under comparison four different row arrangements: CR30 (continuous rows 30 cm apart), CR60 (continuous rows 60 cm apart), CR90 (continuous rows 90 cm apart) and TR (twin rows with a distance of 30 cm inside and 60 cm between twin rows). The plant population on the row (12 plants m-1) was constant and according the row…
Clasificación molecular de los componentes de los aceites de Eucalyptus camaldulensis y de Mentha pulegium
2020
Eucalyptus and Mentha remain flavours in agro-food manufacturing. Oils and components present antifungal potency vs . decay of fruits; E. camaldulensis is led by 1,8-cineole and a -pinene, unlike M. pulegium , which is led by pulegone. The antifungal activity of M. pulegium is three times more frequent than that of E. camaldulensis . The phytochemicals present synergy. Categorization is recommended on the basis of information entropy . The quantity of C-C double bonds, O-atoms and cycles cluster structures. The procedure undergoes a combinatorial upsurge. Nevertheless, following equipartition conjecture, one gets a criterion for selection. Entropy allows clustering phytochemicals according …
Effect of cooking and legume species upon calcium, iron and zinc uptake by Caco-2 cells
2006
Abstract An in vitro system, consisting of simulated gastrointestinal digestion and Caco-2 cell culture, was used to estimate the uptake of calcium, iron and zinc from white beans, chickpeas and lentils, and the effect of cooking upon uptake, with the ultimate aim of evaluating legumes as a dietary source of the aforementioned minerals. In raw products, differences were observed in the uptake percentages by Caco-2 cells of a same mineral from different legumes, although these were not related to the total mineral content. In the three elements studied, the highest uptake values corresponded to chickpeas. Traditional cooking significantly ( p 0.05 ) increased the uptake (%) of calcium, iron …
Thermal lens spectrometry in biochemical analysis.
1994
The photothermal spectroscopic techniques, with special emphasis on the thermal lens spectrometry (TLS), are introduced to the non-specialist in laser spectroscopy. The following topics are treated on an elementary basis: fundamentals and analytical characteristics, instrumentation, selectivity and multi-wavelength capability, the models describing the signal-concentration relationship, the sensitivity, background noise and limits of detection, the influence of light scattering and flow. Applications related to the fields of clinical and biochemical analysis and organic pollution are given. The thermal lens circular dichroism and the infrared TLS are also briefly outlined.
Multiple-plane image formation by Walsh zone plates.
2018
[EN] A radial Walsh filter is a phase binary diffractive optical element characterized by a set of concentric rings that take the phase values 0 or ¿, corresponding to the values + 1 or ¿1 of a given radial Walsh function. Therefore, a Walsh filter can be re-interpreted as an aperiodic multifocal zone plate, capable to produce images of multiple planes simultaneously in a single output plane of an image forming system. In this paper, we experimentally demonstrate for the first time the focusing capabilities of these structures. Additionally, we report the first achievement of images of multiple-plane objects in a single image plane with these aperiodic diffractive lenses.
Electro-optic control of photographic imaging quality through ‘Smart Glass’ windows in optics demonstrations
2017
An experimental setup allowing the modeling of conditions in optical devices and in the eye at various degrees of scattering such as cataract pathology in human eyes is presented. The scattering in cells of polymer-dispersed liquid crystals (PDLCs) and 'Smart Glass' windows is used in the modeling experiments. Both applications are used as optical obstacles placed in different positions of the optical information flow pathway either directly on the stimuli demonstration computer screen or mounted directly after the image-formation lens of a digital camera. The degree of scattering is changed continuously by applying an AC voltage of up to 30–80 V to the PDLC cell. The setup uses a camera wi…
Automatic image enhancement by picture fusion
2005
This paper describes an automatic technique able to fuse different images of the same scene, acquired with different camera settings, in order to obtain an enhanced single representation of the interested. This allows to extend the functionalities (depth of field, dynamic range) of medium and low cost digital cameras. When Multi-Scale Decomposition (MSD) is used on differently focused images, magnification and blurring effects of lens focusing systems often compromise the final image with unpleasant artifacts. In our approach new techniques able to reduce these artifacts are introduced. Even if the algorithm has been essentially designed to extend depth of field it can be also used on multi…
Improved multi-resolution image fusion
2005
This work describes an automatic technique able to fuse different images of the same scene, acquired at different settings, in order to obtain an enhanced single representation of the scene of interest by an improved picture fusion scheme. This allows the extending of the functionalities (depth of field, dynamic range) of medium and low cost digital cameras. When multi-scale decomposition is used on multi-focused images, magnification effects of the lens focusing system cause an incorrect estimation of all pixels in the final image. In our approach new techniques able to reduce these artifacts are introduced. The algorithm has been applied both on full RGB and on color filter array (CFA) im…