scholarly journals An Explanation of Subsurface Optical Pathways through Food Myosystems and their Effect on Colorimetry

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Howard James Swatland
Keyword(s):  
Diffuse Reflectance ◽  
Incident Light ◽  
Muscle Fibers ◽  
Anaerobic Glycolysis ◽  
Post Mortem ◽  
Electrical Capacitance ◽  
Scattering Of Light ◽  
Light Passing ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity

Light may pass along and across the long axes of muscle fibers in any food myosystem. Thus, incident light may be scattered in several ways before some of it reappears at the surface as diffuse reflectance.  Pathways may be short if scattering is strong, or long if scattering is weak. Short pathways minimize selective absorbance by chromophores such as myoglobin, while long pathways maximize selective absorbance.  Many food myosystems exhibit a post-mortem decrease in pH caused by anaerobic glycolysis with a series of microstructural changes – glycogen granules between myofibrils are lost, myofibrils shrink laterally as myofilaments move closer together, water moves from within myofibrils to the space between them, muscle fiber membranes leak and lose their electrical capacitance, and myoglobin is flushed into the fluid filled spaces between muscle fibers. These changes increase scattering of light passing across the long axes of muscle fibers.  Scattering of light along muscle fibers is caused by sarcomere discs (A-bands).  Interference from one or a small number of sarcomere discs may cause iridescence, but in most cases interference from numerous discs causes achromatic diffuse reflectance. Commission International de l’Éclairage (CIE) chromaticity coordinates were calculated for various subsurface optical pathways. Pathways across versus along muscle fibers had a strong effect on CIE y (r = 0.84, P < 0.01) and an even stronger effect on CIE Y% (r = 0.95, P < 0.005).

scholarly journals Effects of Bi3+ Ion-Doped on the Microstructure and Photoluminescence of La0.97Pr0.03VO4 Phosphor

2021 ◽  
Vol 6 (3) ◽  
pp. 191-198
Author(s):  
Hao-Long Chen ◽  
Hung-Rung Shih ◽  
Sean Wu ◽  
Yee-Shin Chang
Keyword(s):  
White Light ◽  
Emission Intensity ◽  
Sol Gel ◽  
Blue Shift ◽  
Light Emitting ◽  
Light Region ◽  
Chromaticity Coordinates ◽  
Ion Doping ◽  
Ion Contents ◽  
Cie Chromaticity

The objective of this paper is to enhance the emission intensity of La0.97Pr0.03VO4 single-phased white light emitting phosphor. The Bi3+ ion-doped La0.97Pr0.03VO4 single-phased white light emitting phosphors are synthesized using a sol-gel method. The structure and photoluminescence properties of (La0.97-yBiy)Pr0.03VO4 (y = 0-0.05) phosphor are also examined. The XRD results show that the structure of La0.97Pr0.03VO4 phosphors with different concentrations of Bi3+ ion doping keeps the monoclinic structure. The SEM results show that the phosphor particles become smoother when the Bi3+ ion is doped. The excitation band for La0.97Pr0.03VO4 phosphor exhibits a blue shift from 320 nm to 308 nm as the Bi3+ ion contents are increased. The maximum emission intensity is achieved for a Bi3+ ion content of 0.5 mol%, which is about 30% greater than that with no Bi3+ ion doped. The CIE chromaticity coordinates are all located in the near white light region for different Bi3+ ion-doped La0.97Pr0.03VO4 phosphors.

A New Deep Red-Emitting Mn2+-Activated SrLaGa3S6O Phosphor

2012 ◽  
Vol 531-532 ◽  
pp. 145-148 ◽  
Author(s):  
Rui Jin Yu ◽  
Jin Young Park ◽  
Hyun Kyoung Yang ◽  
Byung Kee Moon ◽  
Byung Chun Choi ◽  
...  
Keyword(s):  
Broad Band ◽  
Emission Spectra ◽  
Solid State Reaction Method ◽  
White Led ◽  
Photoluminescence Excitation ◽  
Led Lighting ◽  
Display Devices ◽  
Chromaticity Coordinates ◽  
Standard Values ◽  
Cie Chromaticity

A new deep red-emitting Mn2+-activated SrLaGa3S6O phosphor was first prepared by a solid-state reaction method. Their luminescence properties were investigated by photoluminescence excitation and emission spectra. The emission spectrum shows a broad band with an emission maximum at 668 nm under the host excitation of 340 nm. The full width at half maximum (FWHM) of the emission peak is about 83 nm. The CIE chromaticity coordinates (x = 0.673 and y = 0.312) shows that the phosphor emission is in the deep red region and were very near to the NTSC standard values for red. Since the excitation band of the phosphor lies in the near UV excitable region, giving a deep red emission, it can be used for applications in near UV phosphor converted white LED lighting and display devices.

scholarly journals Lead Borate Glasses and Glass-Ceramics Singly Doped with Dy3+ for White LEDs

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5022
Author(s):  
Agata Górny ◽  
Marta Kuwik ◽  
Wojciech A. Pisarski ◽  
Joanna Pisarska
Keyword(s):  
White Light ◽  
Glass Ceramics ◽  
Borate Glasses ◽  
Spectroscopic Techniques ◽  
Lead Borate ◽  
White Leds ◽  
Lead Borate Glasses ◽  
Chromaticity Coordinates ◽  
Potential Applications ◽  
Cie Chromaticity

In this paper, some series of lead borate glasses and glass ceramics singly doped with Dy3+ ions were prepared and then studied using spectroscopic techniques. Our research includes mainly studies of the luminescence properties of received materials for white light. The luminescence bands associated with the characteristic 4F9/2→6H15/2 (blue), 4F9/2→6H13/2 (yellow) and 4F9/2→6H11/2 (red) transitions of trivalent dysprosium in lead borate systems are well observed. In particular, the Commission Internationale de I’Eclairage (CIE) chromaticity coordinates (x, y) were calculated in relation to potential applications for white light-emitting diodes (W-LEDs). Their values depend on the relative B2O3/PbO ratios and PbX2 contents (where X = Cl, F, Br) in glass composition. For glass-ceramics, the chromaticity coordinates are changed significantly under different excitation wavelengths.

Perovskite white light-emitting diodes with a perovskite emissive layer blended with rhodamine 6G

2020 ◽  
Vol 8 (37) ◽  
pp. 12951-12958 ◽  
Author(s):  
Che-Yu Chang ◽  
Wei-Li Hong ◽  
Pei-Hsuan Lo ◽  
Tzu-Hsiang Wen ◽  
Sheng-Fu Horng ◽  
...  
Keyword(s):  
White Light ◽  
Light Emitting Diodes ◽  
Rhodamine 6G ◽  
Light Emitting ◽  
Emissive Layer ◽  
Chromaticity Coordinates ◽  
Halide Perovskites ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

Perovskite white light-emitting diodes with only a single emissive layer of halide perovskites and rhodamine 6G were realized with the CIE chromaticity coordinates of (0.33, 0.40).

Optical Characterization of Si Nanowires: Dependence with Substrate Orientation and Light Polarization

2014 ◽  
Vol 1666 ◽  
Author(s):  
Juan A. Badán ◽  
Ricardo E. Marotti ◽  
Enrique A. Dalchiele ◽  
Daniel Ariosa ◽  
Francisco Martín ◽  
...  
Keyword(s):  
Self Assembly ◽  
Diffuse Reflectance ◽  
Incident Light ◽  
Light Polarization ◽  
Nanowire Arrays ◽  
Angle Of Incidence ◽  
Interference Effects ◽  
Si Nanowires ◽  
Total Reflectance

ABSTRACTOptical properties of Si nanowire arrays (SiNWs) prepared on p-doped Si(111) and Si(100) substrates are studied. The SiNWs were synthesized by self-assembly electroless metal deposition nanoelectrochemistry in an ionic silver HF solution through selective etching. Total reflectance (Rt) and total diffuse reflectance (Rdt) of SiNWs change drastically in comparison to polished Si. To understand these changes diffuse reflectance (Rd) with polarized incident light was studied. For samples prepared on Si(111), the wavelength integrated Rd (wIRd) shows maxima at certain angle of incidence θ and it does not depend on light polarization. Moreover, Rdt of SiNWs prepared on Si(111) can be modeled as an ensemble of diffuse reflectors. For samples prepared on Si(100) wIRd increases with θ, being greater when the light electric field is parallel to the plane of incidence. Also, Rd spectra show structures due to interference effects. For these reasons SiNWs prepared on Si(100) can be considered as a thin film whose refractive index depends on light polarization.

Synthesis and Luminescence Properties of a Blue-Emitting Sr3NaLu(PO4)3F:Eu2+ Phosphor

2017 ◽  
Vol 727 ◽  
pp. 623-627 ◽  
Author(s):  
Zai Fa Yang ◽  
Deng Hui Xu ◽  
Xue Dong Gao ◽  
Jiang Nan Du ◽  
Jia Yue Sun
Keyword(s):  
Blue Emission ◽  
Fluorescence Decay ◽  
Ultraviolet Region ◽  
X Ray Diffraction ◽  
Blue Emission Band ◽  
Light Emitting ◽  
Near Ultraviolet ◽  
Chromaticity Coordinates ◽  
Cie Chromaticity ◽  
White Light Emitting Diodes

A novel blue-emitting Sr3NaLu (PO4)3F:Eu2+ phosphor for white light-emitting diodes (w-LEDs) have been successfully prepared via the solid-state reaction. The crystal structure and phase of the prepared phosphors were investigated using X-ray diffraction (XRD). The band gap of Sr3NaLu (PO4)3F was estimated to be about 5.79 eV from the diffuse reflection spectrum. The Sr3NaLu (PO4)3F:0.05Eu2+ phosphor exhibits an intense and broad excitation band ranging from 200 to 450 nm in the near ultraviolet region and produces a bright blue emission band with the CIE chromaticity coordinates of x = 0.133 and y = 0.148 under the excitation of 365 nm, which were ascribed to the 4f-5d transitions of Eu2+. Moreover, the fluorescence decay curves were also investigated in detail. All the results suggest that Sr3NaLu (PO4)3F:Eu2+ might be a promising blue-emitting phosphor used in w-LEDs.

scholarly journals On the theory of scattering of light

1938 ◽  
Vol 166 (926) ◽  
pp. 425-449 ◽  
Keyword(s):  
Scattered Light ◽  
Incident Light ◽  
Incident Beam ◽  
The State ◽  
Reciprocity Relation ◽  
Scattering Of Light ◽  
Plane Parallel ◽  
Solid Media ◽  
State Of Polarization ◽  
Light Components

In a series of recent investigations R. S. Krishnan (1934-8) demonstrated the existence of a new effect which will be called the Krishnan effect. It relates to the state of polarization of the light scattered by certain liquid or solid media in directions normal to the incident beam. To describe the effect let us denote with π the plane parallel to the direction of observation and to that of the incident beam. Since in the experiment this plane is usually horizontal we denote by H the intensity of those scattered light components which vibrate parallel to this plane, and by V those vibrating normal to π. In a similar manner subscripts h or v indicate whether the incident light vibrates parallel or normal to the plane. We distinguish therefore (see fig. 1) the four light components H h , H v , V h and V v . Following Krishnan the depolarizations are defined by P h = V h / H h , p v = H v / V v , p u = ( H h + H v )/( V h / V v ). p u is the depolarization for natural incident light. For most liquids the observations give, in agreement with the theories of temperature scattering, H h = V h = H v , hence p h = 1, p u = 2 p v /(1+ p v ). The Krishnan effect is the observation that in a number of liquid and solid systems p h = V h / H h ≠ 1, and V h = H v . Krishnan has called (2) the reciprocity relation. All observations have given p h < 1, but none of the present theories exclude the possibility that p h may assume values larger than 1.

High color rendering index single phase white light emitting phosphors based on Tb3+/Sm3+ co-doped CePO4 nanocrystals: the role of Tb3+ as a bridge between Ce3+ and Sm3+

2019 ◽  
Vol 43 (44) ◽  
pp. 17367-17382 ◽  
Author(s):  
Sisira S. ◽  
Linju Ann Jacob ◽  
Kamal P. Mani ◽  
Biju P. R. ◽  
N. V. Unnikrishnan ◽  
...  
Keyword(s):  
White Light ◽  
Single Phase ◽  
Color Temperature ◽  
Light Emitting ◽  
Chromaticity Coordinates ◽  
Color Rendering Index ◽  
Cie Chromaticity ◽  
Color Rendering

Single phase white light emitting CePO4 nanocrystals doped with Tb3+ and Sm3+ were synthesized. The quality of white light is characterized by CIE chromaticity coordinates, color temperature, color rendering index and quantum yield.

Synthesis and Luminescent Properties of Eu3+ Doped CaGd4O7 Phosphors by Solvothermal Reaction Method

2015 ◽  
Vol 15 (10) ◽  
pp. 8028-8033 ◽  
Author(s):  
Yeon Woo Seo ◽  
Mi Noh ◽  
Byung Kee Moon ◽  
Jung Hyun Jeong ◽  
Hyun Kyoung Yang ◽  
...  
Keyword(s):  
Broad Band ◽  
Luminescent Properties ◽  
Solvothermal Reaction ◽  
Sem Images ◽  
Reaction Method ◽  
X Ray ◽  
Chromaticity Coordinates ◽  
Potential Applications ◽  
Xrd Patterns ◽  
Cie Chromaticity

Eu3+ doped CaGd4O7 phosphors have been newly synthesized using a solvothermal reaction method and sintered at 1400 °C. The phase, composition, morphologies, and photoluminescent properties of the phosphors have been well characterized by means of the X-ray diffraction (XRD) patterns, energy dispersive X-ray spectroscopy (EDX), field emission scanning electron microscopy (FE-SEM), photoluminescence (PL) spectroscopy, and decay curves, respectively. The XRD patterns of the as-prepared phosphors confirm their monoclinic structure and the FE-SEM images reveal flower-like morphology, formed through agglomeration. The calculated size of the crystallites was approximately 83 nm. The photoluminescence excitation (PLE) spectra of CaGd4O7: Eu3+ phosphors consist of a broad band due to the charge transfer (CT) electronic transition, and several sharp peaks that can be attributed to the f–f transitions of Eu3+ and Gd3+. The PL spectra exhibited a stronger red emission corresponding to the 5D0→7F2 transition. The CIE chromaticity coordinates of the phosphors were calculated and all the chromaticity coordinates have been placed in the red spectral region. These luminescent powders are expected to have potential applications for white light-emitting diodes (WLEDs) and optical display systems.

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