scholarly journals Universal Synthesizer of Mueller Matrices Based on the Symmetry Properties of the Enpolarizing Ellipsoid

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 983
Author(s):  
José J. Gil ◽  
Ignacio San José
Keyword(s):  
Mathematical Structure ◽  
Mueller Matrix ◽  
Morphological Properties ◽  
Nondestructive Analysis ◽  
Structural Decomposition ◽  
Symmetry Properties ◽  
Mueller Matrices ◽  
Scattering Measurement ◽  
The Way

Polarimetry is today a widely used and powerful tool for nondestructive analysis of the structural and morphological properties of a great variety of material samples, including aerosols and hydrosols, among many others. For each given scattering measurement configuration, absolute Mueller polarimeters provide the most complete polarimetric information, intricately encoded in the 16 parameters of the corresponding Mueller matrix. Thus, the determination of the mathematical structure of the polarimetric information contained in a Mueller matrix constitutes a topic of great interest. In this work, besides a structural decomposition that makes explicit the role played by the diattenuation-polarizance of a general depolarizing medium, a universal synthesizer of Muller matrices is developed. This is based on the concept of an enpolarizing ellipsoid, whose symmetry features are directly linked to the way in which the polarimetric information is organized.

scholarly journals Extent and properties of the regeneration field in the larval legs of cockroaches (Leucophaea maderae)

Development ◽  
1974 ◽  
Vol 32 (1) ◽  
pp. 81-98
Author(s):  
Horst Bohn
Keyword(s):  
Medial Part ◽  
Medial Region ◽  
Anterior Border ◽  
Leucophaea Maderae ◽  
Symmetry Properties ◽  
Cut Surface ◽  
The Way

Previous papers dealing with the regeneration field of cockroach (Leucophaea maderae) legs have shown that two elements of the leg surroundings are indispensable for regeneration of a leg: the basal sclerites and the ‘leg-inducing membrane’ (LIM). The experiments of this paper partly clarify the way in which these two tissues interact; the origin of the regenerative tissues and the determination of polarity and symmetry in the regenerated legs were studied. By combination of sclerites and LIM of different species or segments it has been shown that each of the tissues makes up half of a leg regenerate - the sclerite tissues the anterior longitudinal half, the LIM the posterior longitudinal half. The trochantin was implanted in four different orientations (normal, turned 90° clockwise or anti-clockwise, turned 180°) into a normally orientated field of LIM. The anteriorposterior and medio-lateral axes of the regenerates had the same orientation as those of the sclerites. Therefore, the sclerites alone determine symmetry of the regenerate; the LIM has no influence in this respect. Neither of the two axes is fixed irreversibly in the cells of the LTM; the cells seem able to accept any polarity which is forced upon them by the sclerites. The symmetry properties are more strongly fixed in the cells of the sclerites, but an inversion of polarity (through 180°) is possible for both axes. Regeneration of a leg from the level of the trochantin seems to be initiated by or dependent on a small medial region of the trochantin. A tiny fragment of the medial wedge ofthe trochantin, when transplanted to a field of LIM, can form a complete leg regenerate; a lateral half of the trochantin never does. As long as this small medial part of the trochantin is prevented from making contact with LIM by a praecoxa fragment, no regeneration takes place at the anterior border of the trochantin, even when the greatest part of the border has contact with LTM. The regenerative capacities of the praecoxal sclerite are different at the anterior and posterior cut surfaces, irrespective of the level of the cut and the orientation of the sclerite. An anterior cut surface never forms a leg regenerate, but a posterior cut surface does.

scholarly journals Optical Chirality Determined from Mueller Matrices

2021 ◽  
Vol 11 (15) ◽  
pp. 6742
Author(s):  
Hans Arwin ◽  
Stefan Schoeche ◽  
James Hilfiker ◽  
Mattias Hartveit ◽  
Kenneth Järrendahl ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Constitutive Relations ◽  
Mueller Matrix ◽  
Optical Path ◽  
Electromagnetic Modeling ◽  
Structural Effects ◽  
Polarization Effects ◽  
Optical Chirality ◽  
Mueller Matrices ◽  
Circular Dichroïsm

Optical chirality, in terms of circular birefringence and circular dichroism, is described by its electromagnetic and magnetoelectric material tensors, and the corresponding optical activity contributes to the Mueller matrix. Here, spectroscopic ellipsometry in the spectral range 210–1690 nm is used to address chiral phenomena by measuring Mueller matrices in transmission. Three approaches to determine chirality parameters are discussed. In the first approach, applicable in the absence of linear polarization effects, circular birefringence and circular dichroism are evaluated directly from elements of a Mueller matrix. In the second method, differential decomposition is employed, which allows for the unique separation of chirality parameters from linear anisotropic parameters as well as from depolarization provided that the sample is homogeneous along the optical path. Finally, electromagnetic modeling using the Tellegen constitutive relations is presented. The last method also allows structural effects to be included. The three methods to quantify optical chirality are demonstrated for selected materials, including sugar solutions, α-quartz, liquid crystals, beetle cuticle, and films of cellulose nanocrystals.

scholarly journals III. Further experiments on the vapour densities of potassium and sodium

1879 ◽  
Vol 29 (196-199) ◽  
pp. 490-493 ◽  
Keyword(s):  
Considerable Error ◽  
Exact Determination ◽  
The Way

In one former communication “On the Vapour Densities of Potas­sium and Sodium,” we pointed out the chief obstacles which lay in the way of an exact determination of these constants. Having overcome the chief manipulative difficulties in connexion with the method we described, there still remained the problem for solution as to how far the use of iron bottles in our experiments might affect the results. If the iron retained the metals or allowed their vapours to diffuse with rapidity through it, a considerable error might be produced without its being easily detected.

scholarly journals Dispersive evaluation and surface chemistry of advanced, multifunctional silica/lignin hybrid biomaterials

2013 ◽  
Vol 11 (11) ◽  
pp. 1860-1873 ◽  
Author(s):  
Magdalena Nowacka ◽  
Łukasz Klapiszewski ◽  
Małgorzata Norman ◽  
Teofil Jesionowski
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Electrochemical Sensors ◽  
Relevant Information ◽  
Structural Features ◽  
Kraft Lignin ◽  
Morphological Properties ◽  
Wide Range ◽  
Hybrid Biomaterials

AbstractAdvanced silica/lignin hybrid biomaterials were obtained using hydrated or fumed silicas (Aerosil®200) and Kraft lignin as precursors, which is a cheap and biodegradable natural polymer. To extend the possible range of applications, the silicas were first modified with N-2-(aminoethyl)-3-aminopropyltrimethoxsysilane, and then with Kraft lignin, which had been oxidized with sodium periodate. The SiO2/lignin hybrids and precursors were characterised by means of determination of their physicochemical and dispersive-morphological properties. The effectiveness of silica binding to lignin was verified by FT-IR spectroscopy. The zeta potential value provides relevant information regarding interactions between colloid particles. Measurement of the zeta potential values enabled an indirect assessment of stability for the studied hybrid systems. Determination of zeta potential and density of surface charge also permitted the quantitative analysis of changes in surface charge, and indirectly confirmed the effectiveness of the proposed method for synthesis of SiO2/lignin hybrid materials. A particularly attractive feature for practical use is their stability, especially electrokinetic stability. It is expected that silica/lignin hybrids will find a wide range of applications (polymer fillers, biosorbents, electrochemical sensors), as they combine the unique properties of silica with the specific structural features of lignin. This makes these hybrids biomaterials advanced and multifunctional.

On the Inadequacy of existing Data for determining the Rate of Mortality among Select Lives

1854 ◽  
Vol 4 (1) ◽  
pp. 1-9
Author(s):  
William Spens
Keyword(s):  
First Year ◽  
Sufficient Data ◽  
Existing Data ◽  
Selection Of ◽  
The Way

I. While so much improvement has recently taken place in the arrangement and construction of various tables for facilitating calculations founded on existing data, very little has been done in the way of investigating and correcting the data themselves; and it is feared that the question of the rate of mortality among select lives is still involved in the greatest doubt and obscurity.II. It is not proposed in the present paper to go farther than to show that the rate of mortality, during the first year of selection, of select assured lives is so materially different from what it has hitherto been represented, as to lead to the inference that the data from which the erroneous deduction has been made cannot be true data for the ascertainment of the value of selection. To investigate the rate of mortality of select lives at separate ages, I conceive to be of the utmost importance for the elucidation of truth, and the proper direction of sanatory inquiries; but I do not consider that sufficient data at present exist for the determination of this, and these can only be obtained by a united inquiry. I shall be very happy if the present observations have any effect in hastening such an investigation, which sooner or later must be entered upon.

Study on Calculation of Rock Pressure and Determination of Depth for Shallow Asymmetric Tunnel

2011 ◽  
Vol 261-263 ◽  
pp. 1034-1038 ◽  
Author(s):  
Xiao Jun Zhou
Keyword(s):  
Rock Pressure ◽  
Calculation Method ◽  
Tunnel Structure ◽  
The Way

The method to calculate rock pressure for shallow asymmetric tunnel is analyzed by means of taking a mountainous tunnel with semicircular crown and straight sidewall as the object in this paper. The calculation method of tunnel rock pressure has been presented with consideration of both tunnel structure size and its overburden depth. Finally the way to determine the shallow or profound depth of asymmetric tunnel is also obtained.

scholarly journals Statistical error in counting experiments

1935 ◽  
Vol 149 (868) ◽  
pp. 467-486 ◽  
Keyword(s):  
Finite Number ◽  
Statistical Error ◽  
Single Particles ◽  
Exact Determination ◽  
Statistical Laws ◽  
The Way

Experiments in which single particles are studied with the aid of counters would, in principle, lead to an exact determination of the statistical laws governing the behaviour of these particles if the number of counted particles were infinitely large. With a finite number of counts, however, a finite statistical error will always remain. This error depends upon the number of counts and upon the way in which one makes use of the counter readings to calculate the parameters entering into the statistical laws. The purpose of the following investigation is to show for some typical cases which way of calculating has to be adopted in order to make the error a minimum.

scholarly journals Direct Determination of Ascorbic Acid in a Grapefruit: Paving the Way for In Vivo Spectroelectrochemistry

2017 ◽  
Vol 89 (3) ◽  
pp. 1815-1822 ◽  
Author(s):  
Jesus Garoz-Ruiz ◽  
Aranzazu Heras ◽  
Alvaro Colina
Keyword(s):  
Ascorbic Acid ◽  
Direct Determination ◽  
The Way

Symmetry properties of the Mueller matrix

1987 ◽  
Vol 115 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Alfred Schönhofer ◽  
Hans-Georg Kuball
Keyword(s):  
Mueller Matrix ◽  
Symmetry Properties
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