scholarly journals Bidirectional reflectance measurement of tungsten samples to assess reflection model in WEST tokamak

2021 ◽  
Vol 92 (9) ◽  
pp. 093501
Author(s):  
M. Ben Yaala ◽  
M.-H. Aumeunier ◽  
R. Steiner ◽  
M. Schönenberger ◽  
C. Martin ◽  
...  
Keyword(s):  
Bidirectional Reflectance ◽  
Reflectance Measurement ◽  
Reflection Model

scholarly journals Bidirectional Reflectance Measurement and Reflection Model Fitting of Complex Materials Using an Image-Based Measurement Setup

2018 ◽  
Vol 4 (11) ◽  
pp. 136 ◽  
Author(s):  
Aditya Sole ◽  
Ivar Farup ◽  
Peter Nussbaum ◽  
Shoji Tominaga
Keyword(s):  
Optical Properties ◽  
Model Fitting ◽  
Complex Materials ◽  
Bidirectional Reflectance ◽  
Reflectance Measurement ◽  
Visual Appearance ◽  
Reflection Model ◽  
Packaging Industry ◽  
Reflection Models

Materials with a complex visual appearance, like goniochromatic or non-diffuse, are widely used for the packaging industry. Measuring optical properties of such materials requires a bidirectional approach, and therefore, it is difficult and time consuming to characterize such a material. We investigate the suitability of using an image-based measurement setup to measure materials with a complex visual appearance and model them using two well-established reflection models, Cook–Torrance and isotropic Ward. It was learned that the complex materials typically used in the print and packaging industry, similar to the ones used in this paper, can be measured bidirectionally using our measurement setup, but with a noticeable error. Furthermore, the performance of the reflection models used in this paper shows big errors colorimetrically, especially for the goniochromatic material measured.

Bidirectional Reflectance Measurement of Microstructural Silicon Surfaces

2002 ◽  
Author(s):  
Qunzhi Zhu ◽  
Yu-Jiun Shen ◽  
Zhuomin M. Zhang
Keyword(s):  
Thin Film ◽  
Industrial Applications ◽  
Silicon Wafers ◽  
Silicon Surfaces ◽  
Bidirectional Reflectance ◽  
Reflectance Measurement ◽  
Thin Film Coatings ◽  
Incidence Plane ◽  
Modeling Prediction

Knowledge of the bidirectional reflectance of silicon wafers is needed for the modeling prediction of the emitted and reflected radiation detected by radiometric thermometers, so that these instruments can be properly employed in industrial applications, such as rapid thermal processing chambers [1]. In a previous study [2], the bidirectional reflectance was observed to be sensitive to the surface roughness and coating configuration. For a typical silicon wafer, the surface could be polished, thin-film coated, randomly rough, or patterned. The characteristic parameters of the surface topography fall into the microscale or even nanoscale range. The present paper focuses on the bidirectional reflectance measurement of silicon wafers with thin-film coatings on their randomly rough sides. The reflectance distribution out of the incidence plane is also measured for the sake of a thorough characterization of surface scattering.

A novel predictive method for filler coflocculation with cellulose microfibrils

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK
Keyword(s):  
Negative Impact ◽  
High Strength ◽  
Strength Properties ◽  
Cellulose Microfibrils ◽  
Paper Strength ◽  
Flow Loop ◽  
Cationic Starch ◽  
Reflectance Measurement ◽  
Drainage Rate ◽  
Complete Study

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.

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