Light absorption by a marine diatom: experimental observations and theoretical calculations of the package effect in a small Thalassiosira species

1987 ◽  
Vol 96 (2) ◽  
pp. 299-308 ◽  
Author(s):  
R. J. Geider ◽  
B. A. Osborne
Keyword(s):  
Light Absorption ◽  
Theoretical Calculations ◽  
Marine Diatom ◽  
Package Effect

scholarly journals Development of an improved two-sphere integration technique for quantifying black carbon concentrations in the atmosphere and seasonal snow

2020 ◽  
Vol 13 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Xin Wang ◽  
Xueying Zhang ◽  
Wenjing Di
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Optical Method ◽  
Theoretical Calculations ◽  
Dominant Role ◽  
Northern China ◽  
Least Squares Regression ◽  
Seasonal Snow ◽  
Empirical Procedure ◽  
Total Light

Abstract. An improved two-sphere integration (TSI) technique has been developed to quantify black carbon (BC) concentrations in the atmosphere and seasonal snow. The major advantage of this system is that it combines two distinct integrated spheres to reduce the scattering effect due to light-absorbing particles and thus provides accurate determinations of total light absorption from BC collected on Nuclepore filters. The TSI technique can be calibrated using a series of 15 filter samples of standard fullerene soot. This technique quantifies the mass of BC by separating the spectrally resolved total light absorption into BC and non-BC fractions. To assess the accuracy of the improved system, an empirical procedure for measuring BC concentrations with a two-step thermal–optical method is also applied. Laboratory results indicate that the BC concentrations determined using the TSI technique and theoretical calculations are well correlated (R2=0.99), whereas the thermal–optical method underestimates BC concentrations by 35 %–45 % compared to that measured by the TSI technique. Assessments of the two methods for atmospheric and snow samples revealed excellent agreement, with least-squares regression lines with slopes of 1.72 (r2=0.67) and 0.84 (r2=0.93), respectively. However, the TSI technique is more accurate in quantifications of BC concentrations in both the atmosphere and seasonal snow, with an overall lower uncertainty. Using the improved TSI technique, we find that light absorption at a wavelength of 550 nm due to BC plays a dominant role relative to non-BC light absorption in both the atmosphere (62.76 %–91.84 % of total light absorption) and seasonal snow (43.11 %–88.56 %) over northern China.

scholarly journals Phytoplankton light absorption and the package effect in relation to photosynthetic and photoprotective pigments in the northern tip of Antarctic Peninsula

2017 ◽  
Vol 122 (9) ◽  
pp. 7344-7363 ◽  
Author(s):  
Amabile Ferreira ◽  
Áurea M. Ciotti ◽  
Carlos Rafael B. Mendes ◽  
Julia Uitz ◽  
Annick Bricaud
Keyword(s):  
Antarctic Peninsula ◽  
Light Absorption ◽  
Package Effect

scholarly journals Development of an improved two-sphere integration technique for quantifying black carbon concentrations in the atmosphere and seasonal snow

2019 ◽  
Author(s):  
Xin Wang ◽  
Xueying Zhang
Keyword(s):  
Black Carbon ◽  
Light Absorption ◽  
Optical Method ◽  
Theoretical Calculations ◽  
Dominant Role ◽  
Northern China ◽  
Least Squares Regression ◽  
Seasonal Snow ◽  
Empirical Procedure ◽  
Total Light

Abstract. An improved two-sphere integration (TSI) technique has been developed to quantify black carbon (BC) concentrations in the atmosphere and seasonal snow. The major advantage of this system is that it combines two distinct spheres to reduce the scattering effect due to light-absorbing particles, and thus provides accurate determinations of total light absorption from BC collected on Nuclepore filters. The TSI technique can be calibrated using a series of 15 filter samples of standard fullerene soot. This technique quantifies the mass of BC by separating the spectrally resolved total light absorption into BC and non-BC fractions. To assess the accuracy of the improved system, an empirical procedure for measuring BC concentrations by a two-step thermal–optical method is also applied. Laboratory results indicate that BC concentrations determined using the TSI technique and theoretical calculations are well correlated, whereas the thermal–optical method underestimates BC concentrations by 35 %–45 %. Assessments of the two methods for atmospheric and snow samples revealed excellent agreement, with least-squares regression lines with slopes of 1.72 (r2 = 0.67) and 0.84 (r2 = 0.93), respectively. However, the TSI technique is more accurate in quantifications of BC concentrations in both the atmosphere and seasonal snow, with an overall lower uncertainty. Using the improved TSI technique, we find that light absorption due to BC plays a dominant role, relative to non-BC light absorption, in both the atmosphere (68.5 %–95.9 % of total light absorption) and seasonal snow (52.3 %–93.3 %) over northern China.

scholarly journals Phytoplankton light absorption and the package effect in California coastal waters

1993 ◽  
Vol 94 ◽  
pp. 217-227 ◽  
Author(s):  
NB Nelson ◽  
BB Prezelin ◽  
RR Bidigare
Keyword(s):  
Coastal Waters ◽  
Light Absorption ◽  
Package Effect

scholarly journals Changes in light absorption by the chloroplast, related to its structural transformations

2015 ◽  
Vol 46 (2) ◽  
pp. 369-380 ◽  
Author(s):  
J. Zurzycki ◽  
H. Gabryś
Keyword(s):  
Light Absorption ◽  
Theoretical Calculations ◽  
Structural Transformations ◽  
Mean Intensity ◽  
Low Intensity ◽  
Maximal Amount ◽  
True Shape ◽  
Ellipsoid Of Revolution ◽  
The Mean ◽  
The One

The changes in light absorption of single chloroplasts and one layer of chloroplasts related to their structural transformations were considered. Theoretical calculations of light absorption (E<sub>A</sub>) and transmission (E<sub>T</sub>) as well as for the mean intensity of absorption (I<sub>A</sub>) for the ellipsoid of revolution were given by the formulas 3,2 and l respectively. It was shown that the true shape of <i>Funaria</i> chloroplasts can be considered as ellipsoid of revolution. From the four conformational states of chloroplasts the most flattened one (corresponding to the low intensity of illumination) absorbs maximal amount of light energy. For the one layer of chloroplasts the changes in light absorption connected with structural transformations were estimated as ca. 4%.

scholarly journals Sulfur-Doped BiOCl with Enhanced Light Absorption and Photocatalytic Water Oxidation Activity

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2221
Author(s):  
Ruilian Qi ◽  
Jian Liu ◽  
Huanxiang Yuan ◽  
Yu Yu
Keyword(s):  
Light Absorption ◽  
Water Oxidation ◽  
Photocatalytic Performance ◽  
Theoretical Calculations ◽  
Environmental Concerns ◽  
Oxidation Activity ◽  
Co Catalyst ◽  
Oxidation Properties ◽  
Powerful Strategy ◽  
Visible Light Photocatalytic

Photocatalysis is a powerful strategy to address energy and environmental concerns. Sulfur-doped BiOCl was prepared through a facial hydrothermal method to improve the photocatalytic performance. Experimental results and theoretical calculations demonstrated that the band structure of the sulfur-doped BiOCl was optimally regulated and the light absorption range was expanded. It showed excellent visible-light photocatalytic water oxidation properties with a rate of 141.7 μmol h−1 g−1 (almost 44 times of that of the commercial BiOCl) with Pt as co-catalyst.

Electrochromism of alkylene-linked discrete chromophore polymers with broad radical cation light absorption

2018 ◽  
Vol 9 (22) ◽  
pp. 3055-3066 ◽  
Author(s):  
Dylan T. Christiansen ◽  
David L. Wheeler ◽  
Aimée L. Tomlinson ◽  
John R. Reynolds
Keyword(s):  
Radical Cation ◽  
Light Absorption ◽  
Theoretical Calculations ◽  
Polymeric Materials

This paper details the theoretical calculations, synthesis, and electrochromism of polymeric materials consisting of conjugated chromophores separated by nonconjugated linkers.

The Calculation and Analysis of the InP/InxGa1-xAsyP1-y Optical Properties by Molecular Dynamics

2012 ◽  
Vol 590 ◽  
pp. 143-147
Author(s):  
Ji Ming Zhu
Keyword(s):  
Molecular Dynamics ◽  
Optical Properties ◽  
Light Absorption ◽  
Fiber Optic ◽  
Theoretical Calculations ◽  
Semiconductor Materials ◽  
Absorption Properties ◽  
Temperature Conditions ◽  
Fiber Optic Sensing ◽  
Doping Ratio

This paper has studied the optical properties of the semiconductor materials InP/InGaAsP from the molecular dynamics under different temperature conditions, and analyzed the effect of the different doping ratio on the light absorption properties of InxGa1-xAsyP1-y。 The research of this topic provides a method from the theoretical calculations for in search of new fiber-optic sensing materials.

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