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Polymer/Filler Composites for Optical Diffuse Reflectors
Published in Mahmood Aliofkhazraei, Advances in Nanostructured Composites, 2019
A good understanding of the theories for optical applications is a prerequisite for designing and optimizing polymer-filler nanocomposite reflectors. It is known that the interaction of light with a material includes scattering (reflection and absorption) and transmission of the incident light. Figure 2 presents a simplified schematic diagram of the interaction of an incident light with polymer-filler composites. The polymer-filler composite reflector is treated as spherical fillers of certain radius homogeneously dispersed within the weak-absorbing polymer matrix. When a beam of light strikes on such a material, it is partially scattered from the surface and partially transmitted into the material. The relative fraction of specular reflection and diffuse reflection determines the visual appearance of a bulk material. Usually, the surface of a material looks glossy if specular reflected light is predominated, while it will be matt if the surface-scattered light is the major component. The ceramic fillers (TiO2, SiO2, Al2O3, ZnO, etc.) are strong scattering and non-absorbing in the wavelength of visible light, and the composite reflectors have a largely diffuse appearance. The key factors affecting the reflectance of composites are particle size of fillers, difference of refractive indices between fillers and matrices, and thickness of reflectors (Berger et al. 2007).
Introduction to Human Medical Thermography
Published in James Stewart Campbell, M. Nathaniel Mead, Human Medical Thermography, 2023
James Stewart Campbell, M. Nathaniel Mead
The advent of high-resolution, full-color digital display devices has revolutionized the visual appearance of thermograms. The old scanner FAX and analog displays showed a very limited number of color or greyscale values, obliterating the fine details of the image. Modern color displays have greatly improved the qualitative (visual) interpretation of infrared images, allowing the thermographer to view body surface temperatures much as a radiologist views a properly exposed X-ray. The range of surface temperatures encountered is converted to a smooth greyscale or spectral color image that best matches the capabilities of the human eye.
Lighting Maintenance
Published in Craig DiLouie, Lighting Redesign for Existing Buildings, 2020
Lighting maintenance is essential because the performance of all lighting systems deteriorates over time, which can affect light levels and space appearance. Lighting components fail and must be replaced. Declining light levels, burnouts and color shift can affect the visual appearance of the space. And dirt and dust accumulation on luminaire and room surfaces, and deterioration of those surfaces themselves, will steadily reduce the amount of light output that reaches the workplane where it is needed. Maintenance can mitigate all of these problems.
Graininess characterization by multidimensional scaling
Published in Journal of Modern Optics, 2019
E. Perales, F. J. Burgos, M. Vilaseca, V. Viqueira, F. M. Martínez-Verdú
The visual appearance of a product is important for different reasons. On the one hand, visual appearance allows the manufacturer to know about the reproducibility of its production; i.e. it is an index of the quality control level. In different industrial sectors (leather, glass, cosmetics, ceramics, printed materials, etc.), the final quality control is still done by making visual observations because measurement systems have not yet reached the required level of sensitivity. On the other hand, the visual appearance of a product is a critical parameter implicated in customers’ purchase decisions. For these reasons, in recent years, many different efforts have been made by industrial manufacturers to provide attractive and sophisticated visual effects by using, for instance, goniochromatic pigments (1–5).