Pulps. Determination of fibre coarseness by automated optical analysis. Polarized light method

2015 ◽  
Keyword(s):  
Polarized Light ◽  
Optical Analysis

scholarly journals An empirical method for absolute calibration of coccolith thickness

2017 ◽  
Author(s):  
Saúl González-Lemos ◽  
José Guitián ◽  
Miguel-Ángel Fuertes ◽  
José-Abel Flores ◽  
Heather M. Stoll
Keyword(s):  
Laboratory Data ◽  
Polarized Light ◽  
Empirical Method ◽  
Absolute Calibration ◽  
Light Spectra ◽  
Independent Determination ◽  
Data Comparability ◽  
Calibration Materials ◽  
Constant Slope

Abstract. As major calcifiers in the open ocean, coccolithophores play a key role in the marine carbon cycle. Because they may be sensitive to changing CO2 and ocean acidification, there is significant interest in quantifying past and present variations in their cellular calcification by quantifying the thickness of the coccoliths or calcite plates that cover their cells. Polarized light microscopy has emerged as a key tool for quantifying the thickness of these calcite plates, but the reproducibility and accuracy of such determinations has been limited by the absence of suitable calibration materials in the thickness range of coccoliths (0–4 microns). Here, we describe the fabrication of a calcite wedge with a constant slope over 15 this thickness range, and the independent determination of calcite thickness along the wedge profile. We show how the calcite wedge provides more robust calibrations in the 0 to 1.55 μm range than previous approaches using rhabdoliths. We show the particular advantages of the calcite wedge approach for developing equations to relate thickness to the interference colors that arise in calcite in the thickness range between 1.55 and 4 μm. The calcite wedge approach can be applied to develop equations relevant to the particular light spectra and intensity of any polarized light microscope system and could significantly improve within and inter-laboratory data comparability.

Infrared Spectrum in Polarized Light of CH2Br2 and CD2Br2. Determination of the Crystal Structure

1968 ◽  
Vol 49 (12) ◽  
pp. 5438-5444 ◽  
Author(s):  
M. P. Marzocchi ◽  
P. Manzelli ◽  
V. Schettino ◽  
S. Califano
Keyword(s):  
Crystal Structure ◽  
Infrared Spectrum ◽  
Polarized Light

scholarly journals Histochemical Differential Diagnosis and Polarization Optical Analysis of Amyloid and Amyloidosis

2006 ◽  
Vol 6 ◽  
pp. 154-168 ◽  
Author(s):  
M. Bély
Keyword(s):  
Differential Diagnosis ◽  
Congo Red ◽  
Early Recognition ◽  
Polarized Light ◽  
Optical Analysis ◽  
Early Start ◽  
Amyloid Deposits ◽  
Protein Fibrils ◽  
Congo Red Staining ◽  
Sensitive Method

Amyloidosis is characterized by extracellular deposition of protein fibrils of chemically heterogeneous composition. Early recognition and identification of amyloid deposits allows an early start of therapy, which may entail a better prognosis. Congo red staining according to Romhányi (1971) is a highly specific and sensitive method for early microscopic recognition of amyloidosis. The main and most important types of amyloidosis may be distinguished by classic histochemical methods of performate pretreatment according to Romhányi (1979), or by KMnO4oxidation according to Wright (1977) followed by Congo red staining and viewed under polarized light. Differences in the speed of breakdown (disintegration) of amyloid deposits according to Bély and Apáthy allow a more precise distinction of various types of amyloid.

scholarly journals Problems of Menotactic Orientation According to the Polarized Light of the Sky

1975 ◽  
Vol 30 (1-2) ◽  
pp. 88-90 ◽  
Author(s):  
Kuno Kirschfeld ◽  
M. Lindauer ◽  
H. Martin
Keyword(s):  
Infinite Number ◽  
Polarized Light ◽  
The Sun ◽  
Number Of Solutions ◽  
Special Cases ◽  
Linearly Polarized ◽  
Vector Direction

Abstract It is shown that the knowledge of the E-vector direction of the linearly polarized light at any point of the sky alone is insufficient for the determination of the position of the sun. If the E-vector direction of a second point is not known the knowledge of at least one other parameter is necessary. This parameter might be the height of the sun over the horizon. With the knowledge of the height the infinite number of solutions for the sun’s position becomes reduced to two, or in special cases to one. These cases are derived.

scholarly journals I. On the determination of Verdet’s constant in absolute units

1877 ◽  
Vol 167 ◽  
pp. 1-34 ◽  
Keyword(s):  
Magnetic Force ◽  
Polarized Light ◽  
The Subject

In the year 1845 Faraday discovered that if plane polarized light passes through certain media, and these media be acted on by a sufficiently powerful magnetic force, the plane of polarization is rotated. About the year 1853 M. Verdet commenced a long and exhaustive examination of the subject, and his first result was published in Ann. de Chimie et de Phys. 3 sér. tom. xli.

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