scholarly journals Optical properties and masking capacity of flowable giomers

2020 ◽  
Author(s):  
Mara Elena Rusnac ◽  
Cristina Gasparik ◽  
Ada Gabriela Delean ◽  
Alexandra Iulia Aghiorghiesei ◽  
Diana Dudea
Keyword(s):  
Optical Properties ◽  
Spectral Reflectance ◽  
Statistical Analyses ◽  
Significance Tests ◽  
Color Coordinates ◽  
Paired Samples ◽  
Color Differences ◽  
Colored Background

Background and aims. To assess the color, translucency and masking properties of novel flowable giomers. Methods. Three flowable giomers were used for the fabrication of 1-mm thick samples (n=126) in three consistencies (Beautifil flow Plus X F00; Beautifil flow F02; Beautifil flow Plus X F03, Shofu Dental Corporation, Japan) and two shades (A2 and A3). The relative spectral reflectance was recorded over white, black, C3, and a tested-sample colored background. Lightness (L*), and color coordinates a* and b*, Relative Translucency parameter (RTP00) and masking capacity of C3 background were calculated; differences in color and translucency were compared with thresholds for perceptibility and acceptability (PT and AT). Statistical analyses used significance tests for paired samples. Results. All tested materials displayed increased values of L*: for A2 F00=86.16(±0.86), F02=86.39(±0.63), F03=86.40(±0.63); for A3: F00=84.24(±0.58), F02=83.34(±0.3), F03=84.19(±0.4), as well as of RTP: for A2 F00=30.34(±0.88), F02=31.37(±0.94), F03=31.11(±1.15), for A3 F00=29.64(±1.64), F02=30.79(±1.02), F03=30.1(±1.26). For A2 samples, the masking capacity was significantly different for all materials, whilst for A3 there were differences only between F00-F03 and F02-F03. Conclusions. The tested flowable giomers proved high lightness and translucency. The color differences between the materials with the same designation were below the perceptibility threshold in most cases. In addition, the differences in relative translucency parameters ranged between the perceptibility and acceptability thresholds. All tested flowable giomers had an unacceptable masking capacity for a C3 background.

scholarly journals Plant ecophysiological processes in spectral profiles: perspective from a deciduous broadleaf forest

2021 ◽  
Author(s):  
Hibiki M. Noda ◽  
Hiroyuki Muraoka ◽  
Kenlo Nishida Nasahara
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Spectral Reflectance ◽  
Canopy Structure ◽  
Terrestrial Ecosystems ◽  
Optical Remote Sensing ◽  
Canopy Reflectance ◽  
Broadleaf Forest ◽  
Leaf Optical Properties ◽  
Deciduous Broadleaf Forest

AbstractThe need for progress in satellite remote sensing of terrestrial ecosystems is intensifying under climate change. Further progress in Earth observations of photosynthetic activity and primary production from local to global scales is fundamental to the analysis of the current status and changes in the photosynthetic productivity of terrestrial ecosystems. In this paper, we review plant ecophysiological processes affecting optical properties of the forest canopy which can be measured with optical remote sensing by Earth-observation satellites. Spectral reflectance measured by optical remote sensing is utilized to estimate the temporal and spatial variations in the canopy structure and primary productivity. Optical information reflects the physical characteristics of the targeted vegetation; to use this information efficiently, mechanistic understanding of the basic consequences of plant ecophysiological and optical properties is essential over broad scales, from single leaf to canopy and landscape. In theory, canopy spectral reflectance is regulated by leaf optical properties (reflectance and transmittance spectra) and canopy structure (geometrical distributions of leaf area and angle). In a deciduous broadleaf forest, our measurements and modeling analysis of leaf-level characteristics showed that seasonal changes in chlorophyll content and mesophyll structure of deciduous tree species lead to a seasonal change in leaf optical properties. The canopy reflectance spectrum of the deciduous forest also changes with season. In particular, canopy reflectance in the green region showed a unique pattern in the early growing season: green reflectance increased rapidly after leaf emergence and decreased rapidly after canopy closure. Our model simulation showed that the seasonal change in the leaf optical properties and leaf area index caused this pattern. Based on this understanding we discuss how we can gain ecophysiological information from satellite images at the landscape level. Finally, we discuss the challenges and opportunities of ecophysiological remote sensing by satellites.

PRESENTATION OF STATISTICAL ANALYSES

2001 ◽  
Vol 37 (1) ◽  
pp. 115-123 ◽  
Author(s):  
JANET RILEY
Keyword(s):  
Statistical Analyses ◽  
Significance Tests ◽  
Estimated Parameters ◽  
Selection Of

Instructions are given for the presentation of the results of statistical analyses in Experimental Agriculture. Statistical codes accepted by the journal are defined. Appropriate styles of presentation are illustrated for estimated parameters and variances for a selection of standard statistical analyses. The value of presentations of results of significance tests is discussed. Formats for acceptable tables and graphs are shown. References to further guiding texts are included for non-standard situations.

Wet-Chemical Processing and Angle-Dependent Optical Properties Characterization of Mica/TiO2/Al2O3/M2O3 (M = Fe, Cr, Co) Pigments

2010 ◽  
Vol 663-665 ◽  
pp. 1053-1056
Author(s):  
Hai Yan Du ◽  
Cai Xia Liu ◽  
Jia Yue Sun
Keyword(s):  
Optical Properties ◽  
Metal Ions ◽  
Spectral Reflectance ◽  
Layer Structure ◽  
Chemical Processing ◽  
Color Changes ◽  
Optical Effects ◽  
Coating Method ◽  
Wet Chemical

The four-layer structure angle-dependent pigments with compositions of Mica/TiO2 /Al2O3/Fe2O3, Mica/TiO2/Al2O3/Cr2O3 and Mica/TiO2/Al2O3/Co2O3 were firstly prepared by the wet-chemical coating method, respectively. The as-prepared pigments were performed by precipitating different metal ions, such as Cr3+, Fe3+, Co2+and Al3+, on the pretreated substrates, mica titanium. The optical effects of four-layer structure pigments were investigated in detail by using the five angles’ spectrophotometer. The angle-dependent spectral reflectance and color changes can be quantitatively measured, and the results show that the angle-dependent effects for the as-prepared pigment were improved by the increasing coated Al2O3 layers.

scholarly journals Models of Reflection Nebulae

1965 ◽  
Vol 7 ◽  
pp. 111-121
Author(s):  
T. P. Roark ◽  
J. Mayo Greenberg
Keyword(s):  
Optical Properties ◽  
Simple Model ◽  
Electromagnetic Scattering ◽  
Interstellar Dust ◽  
Radial Direction ◽  
Dust Cloud ◽  
Mie Theory ◽  
Color Differences ◽  
Reflection Nebulae ◽  
Observational Program

A Feasibility Study For an Observational Program was made to investigate models of reflection nebulae. Specifically, for a relatively simple model of an interstellar dust cloud with a source of illumination nearby, predictions of the color of the nebula, relative to the source color, at points along any radial direction from the source are sought. Furthermore, from these color differences, the possibility is studied of discriminating between the effects produced by the cloud-source-observer geometry and those due to the assumed optical properties of the scattering particles. If such discrimination is feasible, the types of observations that would be most useful in separating the effects must be known to the investigator.Plane-parallel slab models similar to those of reference 1 in which the scattering particles are distributed isotropically and homogeneously were used. The scattering properties of the particles were assumed to be those obtained by using the Mie theory of electromagnetic scattering.

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