Search results for "Industrial and Manufacturing Engineering"
showing 10 items of 1866 documents
Physical compensation of phase curvature in digital holographic microscopy by use of programmable liquid lens.
2015
Quantitative phase measurements obtained with digital holographic microscopes are strongly dependent on the optical arrangement of the imaging system. The nontelecentric operation provides phase measurements affected by a parabolic phase factor and requires numerical postprocessing, which does not always remove all the perturbation. Accurate phase measurements are achieved by using the imaging system in telecentric mode. Unfortunately, this condition is not accomplished when a commercial microscope is used as the imaging system. In this paper, we present an approach for obtaining accurate phase measurements in nontelecentric imaging systems without the need for numerical postprocessing. The…
Spatial light modulator phase mask implementation of wavefront encoded 3D computational-optical microscopy
2015
Spatial light modulator (SLM) implementation of wavefront encoding enables various types of engineered pointspread functions (PSFs), including the generalized-cubic and squared-cubic phase mask wavefront encoded (WFE) PSFs, shown to reduce the impact of sample-induced spherical aberration in fluorescence microscopy. This investigation validates dynamic experimental parameter variation of these WFE-PSFs. We find that particular design parameter bounds exist, within which the divergence of computed and experimental WFE-PSFs is of the same order of magnitude as that of computed and experimental conventional PSFs, such that model-based approaches for solving the inverse imaging problem can be a…
Experimental validation of a customized phase mask designed to enable efficient computational optical sectioning microscopy through wavefront encodin…
2017
In this paper, wavefront-encoded (WFE) computational optical sectioning microscopy (COSM) using a fabricated square cubic (SQUBIC) phase mask, designed to render the system less sensitive to depth-induced aberration, is investigated. The WFE-COSM system is characterized by a point spread function (PSF) that does not vary as rapidly with imaging depth compared to the conventional system. Thus, in WFE-COSM, image restoration from large volumes can be achieved using computationally efficient space-invariant (SI) algorithms, thereby avoiding the use of depth-variant algorithms. The fabricated SQUBIC phase mask was first evaluated and found to have a 75% fidelity compared to the theoretical desi…
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.
Hydroxypropyl Cellulose Films Filled with Halloysite Nanotubes/Wax Hybrid Microspheres
2021
The design of novel nanocomposite films based on hydroxypropyl cellulose (HPC) and wax/halloysite hybrid microspheres has been reported. In particular, we first prepared wax/clay Pickering emulsions which were characterized by thermogravimetric analysis and microscopy. SEM images allowed more detailed insights on the nanotubes disposition at the wax/water interface, acting as an outer stabilizing shell. Therefore, the cellulosic biopolymer was added, and it was found that HPC enhances the colloidal stability of the particles, preventing their coalescence and sedimentation. The preparation of the composite films was carried out by the solvent casting method, which enabled the development of …
Geo-visual analytics for urban design in the context of future Internet
2009
The internet, where much of the information has reference to location, together with the latest generation of geographical web services, represent a very large information space that can be used for planning and design. The wealth of information accessible, which requires new forms of interaction and management of the data available, has brought in recent year to the growth of the domain of visual analytics. In addition, the availability of 3D geobrowsers provides the technological means for interactive 3D environments which can be used to access large-scale geographical information. This technological scenario is paving the way to 3D web-based, geo-visual analytics tools for land planning …
Expected principal stress directions under multiaxial random loading. Part I: theoretical aspects of the weight function method
1999
As has been observed experimentally by many authors, the position of the fatigue fracture plane appears to strongly depend on the directions of the principal stresses or strains. In Part I of the present work the expected principal stress directions under multiaxial random loading are theoretically obtained by averaging the instantaneous values of the three Euler angles through some suitable weight functions which are assumed to take into account the main factors influencing fatigue behaviour. Then, in Part II, it is examined how such theoretical principal directions determined by applying the proposed procedure are correlated to the position of the experimental fracture plane for some fati…
Validation and biochemical characterisation of beneficial argan oil treatment in biomass propagation for industrial active dry yeast production
2019
Abstract Biomass propagation for the production of active dry yeasts (ADY) is an economically important industrial process where cellular oxidative stress significantly limits yield and fermentative capacity in the final product. Oxidative stress affects macromolecular cell components, such as lipid and proteins, thus impairing many different cellular processes. Its detrimental effect is prevented and alleviated by complex signalling, detoxifying and protein protecting systems, which can be induced by antioxidant treatments. Here we validate the general beneficial effect of argan oil treatment in bench-top simulations of industrial yeast biomass propagation as an effective technological str…
Wine Oxidation and the Role of Cork
2009
The present review aims to show the state of the art of oxidation mechanisms occurring especially in white wines by taking into account knowledge from different fields in relation to the subject. It is therefore divided into three main parts. First, the mechanisms of oxidation relevant to white wine are discussed in the light of recent scientific literature. Next, the phenomenon of oxygen solubility in wine during the winemaking process, and in particular during bottling is stated theoretically as well as practically. Finally, the aspect of wine conservation after bottling is examined with respect to mass transfers which may occur through the closure, with a special emphasis on cork. Curren…
The affinity for oxygen of polyphenoloxidase in grapes
1973
The influence of oxygen on the reaction of polyphenoloxidase in grapes was determined. Using crude extracts of grapes with a sufficiently high polyphenoloxidase activity on a substrate of pyrocatechol, apparentKm values for oxygen, at 25° C were calculated as 1.1 × 10−4mol (or 9% 02) for Sultana, and 1 × 10−4mol (or 8% O2) for Doradillo grapes. The importance of these figures for wine making is discussed.