Maximization of FDM-3D-Objects Gonio-Appearance Effects Using PLA and ABS Filaments and Combining Several Printing Parameters: "A Case Study".

In order to consider 3D objects from suitable Fused Deposition Modelling (FDM) printers as prototypes for the automotive sector, this sample must be able to reproduce textural effects (sparkle or graininess) or metallic or gonio-appearance to reinforce the attractive appeal of these materials. This study worked with two different commercial filaments: grey metallic PLA (poly(lactic acid)) and ABS (acrylonitrile-butadiene-styrene copolymer) with diffractive pigments. For both materials, a statistical design of experiments (DoE) was carried out to find the printing parameters effect on the final 3D-objects gonio-appearance.

Number of discernible colors for color-deficient observers estimated from the MacAdam limits.

We estimated the number of colors perceived by color normal and color-deficient observers when looking at the theoretic limits of object-color stimuli. These limits, the optimal color stimuli, were computed for a color normal observer and CIE standard illuminant D65, and the resultant colors were expressed in the CIELAB and DIN99d color spaces. The corresponding color volumes for abnormal color vision were computed using models simulating for normal trichromatic observers the appearance for dichromats and anomalous trichomats.

[Health Surveillance Guide of workers using video display terminals: evaluation from a visual health perspective].

Background: Visual health surveillance is essential in the protection of workers who use video display terminals (VDT). In Spain, the most used is the Specific Health Surveillance Guide published in 1999 by the Ministry of Health. The increase of the scientific production upon computer related occupational visual hazards and the experience in its applicability during the last decade justify the aim of this work: reviewing the quality of the guide from the point of view of visual health.