Characterization of Finite Length Composites: Part III. Studies on Thin Sections Extracted from Mouldings (Wafers)

2016 ◽  
Author(s):  
A. Cervenka ◽  
P. S. Allan
Keyword(s):  
Finite Length ◽  
Thin Sections

The Immuno-Electron Microscopic Localization of the Mo-Fe Protein Component of Nitrogenase in Cells of Azotobacter Vinelandii

1973 ◽  
Vol 31 ◽  
pp. 574-575
Author(s):  
J. T. Stasny ◽  
R. C. Burns ◽  
R. W. F. Hardy
Keyword(s):  
Cellular Localization ◽  
Direct Evidence ◽  
Azotobacter Vinelandii ◽  
Intracellular Localization ◽  
Protein Component ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Fe Protein ◽  
Intracytoplasmic Membranes

Structure-functlon studies of biological N2-fixation have correlated the presence of the enzyme nitrogenase with increased numbers of intracytoplasmic membranes in Azotobacter. However no direct evidence has been provided for the internal cellular localization of any nitrogenase. Recent advances concerned with the crystallizatiorTand the electron microscopic characterization of the Mo-Fe protein component of Azotobacter nitrogenase, prompted the use of this purified protein to obtain antibodies (Ab) to be conjugated to electron dense markers for the intracellular localization of the protein by electron microscopy. The present study describes the use of ferritin conjugated to goat antitMo-Fe protein immunoglobulin (IgG) and the observations following its topical application to thin sections of N2-grown Azotobacter.

scholarly journals Mineralogical and Microstructure Analysis for Characterization and Provenance of Ceramic Artifacts from Late Helladic Kastrouli Settlement, Delphi (Central Greece)

Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Vayia Xanthopoulou ◽  
Ioannis Iliopoulos ◽  
Ioannis Liritzis
Keyword(s):  
Raw Materials ◽  
Analytical Techniques ◽  
Sem Analysis ◽  
Petrographic Analysis ◽  
Ceramic Assemblage ◽  
Thin Sections ◽  
Central Greece ◽  
High Calcium ◽  
Local Geology

The present study deals with the characterization of a ceramic assemblage from the Late Mycenaean (Late Helladic III) settlement of Kastrouli, at Desfina near Delphi, Central Greece using various analytical techniques. Kastrouli is located in a strategic position supervising the Mesokampos plateau and the entire peninsula and is related to other nearby coeval settlements. In total 40 ceramic sherds and 8 clay raw materials were analyzed through mineralogical, petrographic and microstructural techniques. Experimental briquettes (DS) made from clayey raw materials collected in the vicinity of Kastrouli, were fired under temperatures (900 and 1050 °C) in oxidizing conditions for comparison with the ancient ceramics. The petrographic analysis performed on thin sections prepared from the sherds has permitted the identification of six main fabric groups and a couple of loners. The aplastic inclusions recognized in all fabric groups but one confirmed the local provenance since they are related to the local geology. Fresh fractures of representative sherds were further examined under a scanning electron microscope (SEM/EDS) helping us to classify them into calcareous (CaO > 6%) and non-calcareous (CaO < 6%) samples (low and high calcium was noted in earlier pXRF data). Here, the ceramic sherds with broad calcium separation are explored on a one-to-one comparison on the basis of detailed mineralogical microstructure. Moreover, their microstructure was studied, aiming to estimate their vitrification stage. The mineralogy of all studied samples was determined by means of X-ray powder diffraction (XRPD), permitting us to test the validity of the firing temperatures revealed by the SEM analysis. The results obtained through the various analytical techniques employed are jointly assessed in order to reveal potters’ technological choices.

Mineralogical characterization of fibrous zeolites from the Kahrizak volcanic suite, south Tehran, Iran

Clay Minerals ◽  
2010 ◽  
Vol 45 (4) ◽  
pp. 507-517 ◽  
Author(s):  
M. Kusehlar ◽  
F. Tutti ◽  
H. Mirnejad ◽  
A. E. Lalonde
Keyword(s):  
Volcanic Rocks ◽  
Hydrothermal Activity ◽  
Scattered Electron ◽  
Northern Iran ◽  
Mineralogical Characterization ◽  
Thin Sections ◽  
Rich Solution ◽  
Cavity Filling ◽  
Fibrous Zeolites

AbstractSelected samples of large cavity filling and vein-type fibrous zeolites from Eocene volcanic rocks in the Kahrizak region, northern Iran, have been studied for their mineralogical and chemical characteristics. X-ray powder diffraction and electron microprobe analyses confirmed the presence of natrolite, mesolite and scolecite with compositions of [Na14.922Ca0.202K0.015Ba0.002] [Al15.697Si24.267O80]·nH2O, [Ca15.714Na14.224][Al46.431Si73.398O240]·nH2O and [Ca7.804Na0.142K0.024Ba0.012Mg0.006][Al15.320Si24.437O80]·nH2O, respectively. In addition, examination of textural relationships in thin sections and back-scattered electron images reveals a paragenetic order in which the Ca-rich zeolites crystallized first. It is most probable that the fibrous zeolites of Kahrizak were formed during two pulses of hydrothermal activity in the area. Scolecite and mesolite were precipitated from Ca-rich solution, whereas the second stage Na-rich, low-temperature fluid crystallized natrolite and reacted with Ca-species.

Electron microscope and physical chemical characterization of C-phycocyanin from fresh extracts of two blue-green algae

1973 ◽  
Vol 19 (7) ◽  
pp. 831-836 ◽  
Author(s):  
Martin Kessel ◽  
Robert MacColl ◽  
Donald S. Berns ◽  
Mercedes R. Edwards
Keyword(s):  
Red Light ◽  
Chemical Characterization ◽  
Thylakoid Membranes ◽  
Sedimentation Velocity ◽  
Particulate Material ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Physical Chemical ◽  
Sedimentation Velocity Centrifugation

The particulate material (intact and dissociated phycobilisomes), adjacent to the thylakoids of Plectonema boryanum and Calothrix parietina, was examined in thin sections and in freshly prepared C-phycocyanin extracts. For the latter a method was developed using spheroplasts of log-phase cells. When examined by sedimentation velocity centrifugation, the sedimentation coefficients of the rapidly extracted C-phycocyanin were found to be 18 S and 5 S. Also, a 10-S boundary was observed with P. boryanum. When C. parietina was grown under red light the 18-S aggregates increased to 20 S. The 18 S particles, in electron micrographs of negatively stained preparations, displayed eight subunits surrounding a central one. The possibility that some subunits fall out of the plane of view is contemplated in proposing a dodecamer arrangement for such particles. The 20-S particles were also examined by electron microscopy. However, the precise number of monomer units associated with either the 18-S or 20-S particles has not yet been ascertained. Thin sections of intact algal cells are presented to demonstrate the presence of phycobilisomes along the outer faces of the thylakoid membranes.

scholarly journals Microstructural characterization of snow, firn and ice

2019 ◽  
Vol 377 (2146) ◽  
pp. 20180162 ◽  
Author(s):  
Ian Baker
Keyword(s):  
Optical Microscopy ◽  
Microstructural Characterization ◽  
Theme Issue ◽  
Thin Sections ◽  
X Ray ◽  
The Future ◽  
Microscopy Techniques

This paper provides an overview of techniques used to characterize the microstructure of snow, firn and ice. These range from traditional optical microscopy techniques such as examining thin sections between crossed polarizers to various electron-optical and X-ray techniques. Techniques that could have an impact on microstructural characterization of snow, firn and ice in the future are briefly outlined. This article is part of the theme issue ‘The physics and chemistry of ice: scaffolding across scales, from the viability of life to the formation of planets’.

Physical Methods and Instruments for Characterizing Hailstones

1961 ◽  
Vol 42 (7) ◽  
pp. 452-466 ◽  
Author(s):  
Roland List
Keyword(s):  
Surface Temperature ◽  
Liquid Water ◽  
Physical Characterization ◽  
Aerodynamic Forces ◽  
Thin Sections ◽  
Physical Methods ◽  
Roughness Surface ◽  
Ice Particles ◽  
Free Falling

All methods and instruments currently being used for the physical characterization of hailstones are listed and discussed. Apart from the simpler measurements of diameter, shape, roughness, surface temperature, etc., particular attention is paid to the aerodynamic forces acting on free-falling hailstones and to the way these forces are ascertained. Further paragraphs are devoted to the technique for obtaining thin sections and to their importance in explaining the growth of ice particles. The application of calorimeters and separators in demonstrating the presence of liquid water in the hailstones is also discussed. All these methods can be used for investigating artificially produced ice particles.

Characterization of Finite Length Composites: Part IV - Structural Studies on Injection Moulded Composites

2016 ◽  
Author(s):  
G. J. Von Bradsky ◽  
R. S. Bailey ◽  
A. J. Cervenka ◽  
H. G. Zachmann ◽  
P. S. Allan
Keyword(s):  
Finite Length ◽  
Structural Studies

scholarly journals Comparison of digital image analysis methods for morphometric characterization of soil aggregates in thin sections

2020 ◽  
pp. 199-222
Author(s):  
O. O. Plotnikova ◽  
T. V. Romanis ◽  
P. G. Kust
Keyword(s):  
Soil Aggregates ◽  
Morphometric Parameters ◽  
Thin Sections ◽  
Whitney Test ◽  
Semiautomatic Segmentation ◽  
Mann Whitney Test ◽  
Segmentation Methods ◽  
Adobe Photoshop ◽  
High Degree

The purpose of this study was to investigate the applicability of semiautomatic segmentation methods for obtaining and evaluating morphometric parameters of soil aggregates in artificially prepared loose samples in soil thin sections. The object of the research is typical arable Chernozem. The aggregates were separated by wet sieving method from loose sample of upper 10 cm of the plowing horizon after erosion by a model shallow water flow on a large erosion tray. The aggregates, loosely scattered on the glass and fixed with polyester resin, were used to produce the thin sections. Images of the thin sections were taken under a polarizing microscope and then were processed using two methods compared: Adobe Photoshop + CTan and Thixomet Pro. Data on morphometric parameters of aggregates were obtained: the shape factor, the degree of roundness and the coefficient of aggregate surface roughness. The convergence of the results obtained using Photoshop + CTan by three researchers was evaluated by comparing samples using the Student's test and the Mann-Whitney test. The convergence of the averaged results obtained using Photoshop + CTan and the results obtained using Thixomet Pro was evaluated using the Mann - Whitney test. No significant differences were found between the parameters of the same aggregates obtained using a combination of Adobe Photoshop and CTan programs by different researchers. No significant differences were found between the parameters of the same aggregates obtained by the compared methods. So, one can conclude that the reliability of determining the morphometric parameters of soil aggregates using Thixomet Pro is comparable to the reliability of results when working with images of sectionsin CTan after binarization in Adobe Photoshop. The method of obtaining data on morphometric parameters of soil aggregates using Thixomet Pro completely eliminates the possibility of subjective error, shows a high degree of automation, reproducibility and reliability of the results obtained, and is faster.

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