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A reduced set of measurement geometries allows the spectral reflectance of special effect coatings to be predicted for any other geometry. A physical model based on flake-related parameters has been used to determine nonredundant measurement geometries for the complete description of the spectral bidirectional reflectance distribution function (BRDF). The analysis of experimental spectral BRDF was carried out by means of principal component analysis. From this analysis, a set of nine measurement geometries was proposed to characterize special effect coatings. It was shown that, for two different special effect coatings, these geometries provide a good prediction of their complete color shift.
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http://dx.doi.org/10.1364/JOSAA.30.000206 | DOI Listing |
J Prosthet Dent
September 2025
Professor, Washington Dental Service Endowed Chair in Dentistry, and Chair, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash.
A practical and novel technique used both in testing and in practice when tightening dental implant screw systems is described for determining the preload implant screw systems, which differs from traditional tightening procedures that are based solely on the application of a predetermined manufacturer specified torque value. Preload is the critical quantity for a reliable joint: about 90% of tightening torque goes into overcoming friction and the remaining amount, approximately 10%, goes into preload. Because of the heavy dependence of torque on friction, the actual preload achieved is subject to large variability of up ±35%, depending on surface conditions (dry, wet, or contaminated).
View Article and Find Full Text PDFObjective: Estimating the probability of pedestrian injuries at different impact speeds is important for research and regulatory efforts related to infrastructure and vehicle design. However, a risk curve is only valuable if it is based on crash data that accurately represent the current vehicle fleet. This study, therefore, aimed to provide an updated estimate of pedestrian injury risk at different severity levels using recent crash data from U.
View Article and Find Full Text PDFJ Endod
September 2025
Dental Specialty Center, Brazilian Military Police, Minas Gerais, Brazil.
Introduction: To evaluate how stepwise enlargement in the mesial root canals of mandibular first molars affect shaping outcomes and irrigant dynamics.
Methods: The shaping ability and irrigant flow patterns in mesial canals of mandibular first molars enlarged with ProTaper Next instruments (25/.06v, 30/.
Rev Sci Instrum
September 2025
LAPLACE, Université de Toulouse, CNRS, INPT, UPS, 118 route de Narbonne, 31062 Toulouse, France.
A two-axis thrust stand is developed and validated experimentally, enabling direct and simultaneous measurements of two components of the thrust vector of an electric thruster. It is made of two piled-up single-axis stages, each having a hanging deformable parallelogram geometry. A mass deposition calibration method is used to calibrate the thrust stand, including crosstalk between axes.
View Article and Find Full Text PDFJ Acoust Soc Am
September 2025
College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266590, China.
The single-difference positioning method could eliminate the systematic error of long periods, which is one of the major factors affecting the seafloor geodetic acoustic positioning accuracy. Due to the poor observation geometry in short observation time, there is collinearity in the coefficient matrix. Therefore, a small observation error may lead to a large error in the least square solution, which is the ill-posed problem of single-difference positioning.
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