Hair Polarized Microscopy

2017 ◽  
pp. 831-834
Author(s):  
Adriana Rakowska
Keyword(s):  
Polarized Microscopy

Evaluation of intercellular lipid lamellae in the stratum corneum by polarized microscopy

2021 ◽  
Author(s):  
Naoki Asada ◽  
Ryo Morita ◽  
Rikae Kamiji ◽  
Mami Kuwajima ◽  
Masahiko Komorisono ◽  
...  
Keyword(s):  
Stratum Corneum ◽  
Polarized Microscopy ◽  
Intercellular Lipid

scholarly journals Optical Microscopy Observations and Construction of Dupin Cyclides at the Isotropic/Smectic A Phase Transition

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4539
Author(s):  
Mikhael Halaby Macary ◽  
Gauthier Damême ◽  
Antoine Gibek ◽  
Valentin Dubuffet ◽  
Benoît Dupuy ◽  
...  
Keyword(s):  
Phase Transition ◽  
Numerical Simulation ◽  
Liquid Crystal ◽  
Optical Microscopy ◽  
Smectic A ◽  
Polarized Microscopy ◽  
Smectic A Phase ◽  
Dupin Cyclides

In this work, we are interested in the nucleation of bâtonnets at the Isotropic/Smectic A phase transition of 10CB liquid crystal. Very often, these bâtonnets are decorated with a large number of focal conics. We present here an example of a bâtonnet obtained by optical crossed polarized microscopy in a frequently observed particular area of the sample. This bâtonnet presents bulges and one of them consists of a tessellation of ellipses. These ellipses are two by two tangent, one to each other, and their confocal hyperbolas merge at the apex of the bâtonnet. We propose a numerical simulation with Python software to reproduce this tiling of ellipses as well as the shape of the smectic layers taking the well-known shape of Dupin cyclides within this particular bâtonnet area.

scholarly journals Enhancement of Birefringence in Reduced Graphene Oxide Doped Liquid Crystal

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 842 ◽  
Author(s):  
Mareddi Bharath Kumar ◽  
Mohammad Awwal Adeshina ◽  
Daekyung Kang ◽  
Youngho Jee ◽  
Taewan Kim ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Liquid Crystal ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Transmission Measurement ◽  
Scanning Calorimetry ◽  
Polarized Microscopy ◽  
Electro Optic ◽  
Reduced Graphene ◽  
5Cb Liquid Crystal

We investigated the effect of reduced graphene oxide (rGO) doping on the birefringence of 5CB liquid crystal (LC). The characteristics of the synthesized rGO and LC-rGO composite with different rGO concentrations were analyzed by atomic force microscopy, X-ray photoelectron spectroscopy, white light polarized microscopy, voltage-dependent transmission measurement, and differential scanning calorimetry. We found that doping LC with an appropriate concentration of rGO enhances the birefringence of the LC. This is mainly due to the improved anisotropy of polarizability, which stems from the high shape anisotropy of rGO. However, the aggregation of rGO reduces the birefringence by decreasing the anisotropy of polarizability as well as the order parameter. Our study shows the promising potential of LC-rGO for developing various electro-optic devices that offer improved electro-optic effects.

scholarly journals From Point to Filament Defects in Hybrid Nematic Films

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Cesare Chiccoli ◽  
Paolo Pasini ◽  
Claudio Zannoni ◽  
Gregor Skačej ◽  
Hiroyuki Yoshida ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Point Defects ◽  
Elastic Constants ◽  
3D Structure ◽  
Support Surface ◽  
Hybrid Films ◽  
Surface Ordering ◽  
Polarized Microscopy ◽  
Homeotropic Alignment

AbstractWe have studied nematic hybrid films with homeotropic alignment at the top surface and various controlled degrees of in plane ordering, going from a random degenerate organization to a completely uniform alignment along one direction, at the bottom one. We show, by Monte Carlo (MC) computer simulations and experiments on photopatterned films with the bottom support surface fabricated with in-plane order similar to the simulated ones, that the point defects observed in the case of random planar orientations at the bottom tend to arrange along a filament as the surface ordering is sufficiently increased. MC simulations complement the polarized microscopy texture observations allowing to inspect the 3D structure of the defects and examine the role of elastic constants.

scholarly journals Natural Stones Used in the Orsi-Marconi Palace Façade (Bologna): A Petro-Mineralogical Characterization

Heritage ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 1109-1123
Author(s):  
Elena Marrocchino ◽  
Chiara Telloli ◽  
Martina Pedrini ◽  
Carmela Vaccaro
Keyword(s):  
Degradation Products ◽  
Mineralogical Composition ◽  
Structural Aspect ◽  
Historical Building ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Polarized Microscopy ◽  
Mineralogical Study ◽  
Natural Stones ◽  
Materials Used

Ancient buildings are important components of the Italian Cultural Heritage and, since the Etruscan Period, Bologna (north-eastern Italy) has always been one of the most flourishing cities both culturally and economically in the Italian and European panorama. The Orsi-Marconi Palace in Bologna presents a monumental façade decorated with many sandstone ornaments of the 16th century. Different samples from different parts of the façade of the building were collected and firstly characterised by macroscopic observations to determine the structural aspect. A petro-mineralogical study on the surfaces of the samples was conducted using a stereomicroscope and Optical Transmitted Light Polarized Microscopy. In addition, X-Ray Fluorescence and X-Ray Powder Diffractometer analyses were carried out to better understand the mineralogical composition of the sandstone materials used and the degradation products from the façades of this historical building. The aim of this work was to better understand how to revalue the sandstone decorations severely affected by deterioration phenomena.

scholarly journals Synthesis and Characterization of Certain Photoactive Liquid Crystalline Poly(ester amides) from 2,5-Pyridine Dicarboxylic Acid

2019 ◽  
Vol 31 (5) ◽  
pp. 997-1001
Author(s):  
V. Chitra ◽  
D. Roopsingh
Keyword(s):  
Dicarboxylic Acid ◽  
Liquid Crystalline ◽  
Uv Light ◽  
Polymeric Materials ◽  
Gel Permeation Chromatography ◽  
Information Storage ◽  
Storage Devices ◽  
Polarized Microscopy ◽  
Pyridine Dicarboxylic Acid ◽  
Optical Information Storage

A new series of four photo-crosslinkable thermotropic liquid crystalline poly(ester amides) were synthesized by direct polycondensation of 2,5-pyridine dicarboxylic acid with two different varying diols and diamines. Two diamines employed in the synthesis were 4,4′-diaminodiphenyl methane and 1,4-diaminobenzene. The arylidene diols 2,5-bis(4-hydroxy-3-methoxybenzylidene)cyclopentanone and 2,6-bis(4-hydroxy-3-methoxybenzylidene)cyclohexanone were also used. The synthesized poly(ester amides) were characterized by qualitative solubility test, FT-IR, 1H and 13C NMR spectra. The monomeric moieties were found to be well incorporated in the polymer back bone. The molecular weight of the polymer was assessed by gel permeation chromatography (GPC). The thermal phase transition behavior and liquid crystallinity of the poly(ester amides) were investigated by differential thermogravimetry (DTG) and hot stage optical polarized microscopy (HOPM), respectively. Interestingly, these poly(ester amides) in dimethylacetamide were found to possess photo-crosslinking characteristics when irradiated by UV light. These polymeric materials may find utility value in optical information storage devices.

scholarly journals Titanium pigment in tissues of drug addicts: report of 5 necropsied cases

2004 ◽  
Vol 59 (2) ◽  
pp. 86-88 ◽  
Author(s):  
Marcus Aurelho de Lima ◽  
Vitorino Modesto dos Santos ◽  
Samia Demachki ◽  
Javier Lazo
Keyword(s):  
Bone Marrow ◽  
Titanium Dioxide ◽  
Forensic Pathology ◽  
Drug Addicts ◽  
Potential Contribution ◽  
Tissue Samples ◽  
Polarized Microscopy ◽  
Body Tissues ◽  
Pathologic Findings ◽  
Morphologic Data

The aim of this report is to describe the anatomic-pathologic findings from necropsies of 5 drug addicts with titanium pigment in several organs after chronic intravenous injection of crushed propoxyphene hydrochloride tablets. Samples from liver, spleen, lungs, lymph nodes, and bone marrow were obtained, and after being grossly studied, they were submitted to evaluation using common light and polarized microscopy. In all 5 cases, a pigment with characteristics of titanium dioxide was found within tissue samples of the organs studied. Our findings suggest that research concerning titanium pigment within body tissues should be enhanced, considering the potential contribution of this morphologic data to forensic pathology.

In-plane Molecular Alignment in Thin Films of Pentacene Grown by Solution Casting and Performance of Thin Film Transistors

2007 ◽  
Vol 1003 ◽  
Author(s):  
Takashi Minakata ◽  
Yutaka Nastume
Keyword(s):  
Thin Films ◽  
Single Crystal ◽  
Crystalline Structure ◽  
Grazing Incidence ◽  
Growth Direction ◽  
Molecular Alignment ◽  
Patterned Substrate ◽  
Polarized Microscopy ◽  
Transmission Electron ◽  
And Performance

AbstractWe have fabricated solution-processed thin films of pentacene by casting solution on a substrate and vaporizing solvent. The films with large oriented platelet domains were obtained by directionally grown condition. Molecular alignment in the directionally grown grains has been studied by several kinds of structural analysis. Oriented domains with the width of several hundreds microns and the length in an order of cm of the films were confirmed by polarized microscopy. In-plane crystalline structure of the domain has been studied by grazing incidence X-ray diffraction (GIXD) and strong anisotropy of in-plane crystalline structure was confirmed. Crystalline growth direction of the film was determined to be b-axis from both transmission electron diffraction and GIXD. Thin films transistors (TFTs) with directionally oriented domains of the films were fabricated on electrode patterned substrate. The observed maximum carrier mobility of 2.7 cm2/Vs was comparable to that of single crystal, which indicated that the quality of the film was almost identical with the single crystal. Correlation between FET performance and growth direction was studied and preferred performance of TFTs with the film grown perpendicularly to the channel was observed.

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