Astigmatism and Pseudoaccommodation in Pseudophakic Eyes

noAdvanced IOLs with circumferential zones of different power provide pseudoaccommodation. We investigated the potential for power variation with meridian, namely astigmatism, to provide pseudo-accommodation. With appropriate power and axis orientations, acceptable pseudo-accommodation can be achieved

Coloring photovoltaic modules using printed textiles: Fabrication, validation and the prediction of appearance & energy yield

The targets set by many nations to increase renewable energy production lead to a greater demand for photovoltaic modules (PV). In order to reduce the additional area required, it is advisable to first utilize existing areas that were previously unused for energy generation. As a result, building-integrated PV modules, especially those integrated into façades, are gaining in importance. However, such PV modules not only provide energy, they also have to meet aesthetic requirements. For a cost-benefit analysis and the calculation of the payback period, an accurate yield prediction is essential. However, a yield prediction for PV modules modified in appearance and mounted vertically onto a façade is less accurate than a yield prognosis for standard and roof-mounted modules. In this work, I present the Colored Textile (CoTex) method, which alters the appearance of PV modules by using imprinted textiles, such as nonwovens. I validate this method by various laboratory and long-term measurements in terms of durability, energy yield and appearance of such CoTex modules. Depending on the selection of the textile used and the printed color, the energy yield varies. For example, a PV module in light gray design achieves an energy yield of 89% compared to a standard module. The CoTex method allows endless possibilities for the appearance of the manufactured modules by using printed materials. Depending on the textiles and printing parameters used, a different appearance is created. To ensure that the appearance and energy output of specific CoTex modules are known before they are manufactured, I perform the simulation of a digital prototype. After calibration based on eight different colored sample modules, a digital prototype can be simulated for any combination of the three printing inks cyan, magenta and yellow. The deviation between the simulated and the measured color are hardly perceptible for an observer, the deviation of the simulated from the measured energy yield is below 2 %. Using the energy yield determined by the digital prototype, a total yield prediction can be performed for a CoTex module. By applying the ground view factor for vertically mounted PV modules and including ground shading from objects in the surrounding area, I reduce the deviation between measured and simulated energy yield by up to 10.5 % over a 12-month period compared to using the standard model to calculate ground reflectance. By adding an angular correction of the transmission of the CoTex layer depending on the position of the sun, the yield prediction for CoTex modules can be performed with an accuracy comparable to that of standard PV modules

3D hybrid wound devices for spatiotemporally controlled release kinetics

This paper presents localized and temporal control of releasekinetics over 3-dimensional (3D) hybridwounddevices to improve wound-healing process. Imaging study is performed to extract wound bed geometry in 3D. Non-Uniform Rational B-Splines (NURBS) based surface lofting is applied to generate functionally graded regions. Diffusion-based releasekinetics model is developed to predict time-based release of loaded modifiers for functionally graded regions. Multi-chamber single nozzle solid freeform dispensing system is used to fabricate wounddevices with controlled dispensing concentration. Spatiotemporal control of biological modifiers thus enables a way to achieve target delivery to improve wound healing

Redefining A in RGBA: Towards a Standard for Graphical 3D Printing

Advances in multimaterial 3D printing have the potential to reproduce various visual appearance attributes of an object in addition to its shape. Since many existing 3D file formats encode color and translucency by RGBA textures mapped to 3D shapes, RGBA information is particularly important for practical applications. In contrast to color (encoded by RGB), which is specified by the object's reflectance, selected viewing conditions and a standard observer, translucency (encoded by A) is neither linked to any measurable physical nor perceptual quantity. Thus, reproducing translucency encoded by A is open for interpretation. In this paper, we propose a rigorous definition for A suitable for use in graphical 3D printing, which is independent of the 3D printing hardware and software, and which links both optical material properties and perceptual uniformity for human observers. By deriving our definition from the absorption and scattering coefficients of virtual homogeneous reference materials with an isotropic phase function, we achieve two important properties. First, a simple adjustment of A is possible, which preserves the translucency appearance if an object is re-scaled for printing. Second, determining the value of A for a real (potentially non-homogeneous) material, can be achieved by minimizing a distance function between light transport measurements of this material and simulated measurements of the reference materials. Such measurements can be conducted by commercial spectrophotometers used in graphic arts. Finally, we conduct visual experiments employing the method of constant stimuli, and derive from them an embedding of A into a nearly perceptually uniform scale of translucency for the reference materials.Comment: 20 pages (incl. appendices), 20 figures. Version with higher quality images: https://cloud-ext.igd.fraunhofer.de/s/pAMH67XjstaNcrF (main article) and https://cloud-ext.igd.fraunhofer.de/s/4rR5bH3FMfNsS5q (appendix). Supplemental material including code: https://cloud-ext.igd.fraunhofer.de/s/9BrZaj5Uh5d0cOU/downloa