A MORPHOMETRIC SYSTEM FOR DESCRIBING THE MICROMORPHOLOGY OF ORGANIC SOILS AND ORGANIC LAYERS

1984 ◽  
Vol 64 (4) ◽  
pp. 495-503 ◽  
Author(s):  
C. A. FOX
Keyword(s):  
Granular Material ◽  
Key Words ◽  
Thin Section ◽  
Particulate Material ◽  
Organic Soils ◽  
Thin Sections ◽  
Organic Layers ◽  
Descriptive System ◽  
Descriptive Method

A descriptive system is outlined for characterizing, in thin sections, the micromorphology of organic soils and organic layers. In each thin section, distinct regions of morphology, fabric zones, can be recognized. Each fabric zone may be composed of various combinations of organic constituents. These constituents are designated as basic morphologic units and four main types are defined: particulate material, granular units, discrete compound particles, and massive-appearing fabric. The fabric zone and basic morphologic units can be coded in a fabric description symbol of the following simple general form [Fabric Unit]1 …[Fabric Unit]n, where [Fabric Unit] represents a particular fabric zone and its basic morphologic units. For example, [PpGa] [Ma] is a fabric description symbol indicating that two fabric zones are identified in the thin section. The first [PpBa] is the dominant fabric zone in the thin section (areal proportion) and is composed of two basic morphologic units, mainly recognizable plant fragments, Pp, and a lesser occurrence of amorphous granular material, Ga. The second fabric unit [Ma] indicates a fabric zone composed of one basic morphologic unit: amorphous massive-appearing fabric, Ma. The system is applied to the micromorphological characterization of a Typic Mesisol from Keswick, Ontario. Key words: Microcorphology, organic soils, descriptive method, characterization

A MORPHOMETRIC SYSTEM FOR DESCRIBING THE MICROMORPHOLOGY OF ORGANIC SOILS AND ORGANIC LAYERS: FURTHER QUANTITATIVE AND QUALITATIVE CHARACTERIZATION

1985 ◽  
Vol 65 (4) ◽  
pp. 695-706 ◽  
Author(s):  
C. A. FOX
Keyword(s):  
Thin Section ◽  
Quantitative Information ◽  
Level Of Detail ◽  
Organic Soils ◽  
Organic Layer ◽  
Qualitative Information ◽  
Organic Layers ◽  
Level Ii ◽  
Distinct Morphology

At the first level of detail of description of a thin section, qualitative information about the occurrence of the fabric zones (regions of distinct morphology) and their basic morphologic units (the various components) were recorded with symbols in a fabric description symbol. At a second level of detail of description, Level II, additional quantitative and qualitative micromorphological information can be included with coding into the fabric description symbol according to the following. general format:[Formula: see text]At Level II description, quantitative information on the areal proportions of the fabric zones and basic morphologic units are recorded with indices in the fabric unit; qualitative data on the kind of boundary relationships between adjacent fabric zones, and quantitative data on the areal occurrence of the fabric zones are recorded with the modifier expression; and both quantitative and qualitative information on the occurrence, morphology, and arrangement of specific features observed in the fabric zones are recorded with the fabric unit descriptor. Depending on the requirements of a study, more than one fabric unit descriptor can be written for each fabric zone that is delineated in a thin section. The procedure for writing fabric description symbols at a Level II detail of description of a thin section is presented and applied to the characterization of the micromorphology of an organic layer from a Typic Mesisol. Key words: Micromorphology, descriptive method, organic soils, characterization

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.

The Nature of Polyhedral Inclusion Bodies of Thiobacillus Neopolitanus

1972 ◽  
Vol 30 ◽  
pp. 316-317
Author(s):  
F. L. Ball ◽  
J. M. Shively ◽  
J. P. Breillatt ◽  
J. E. Caton ◽  
D. H. Brownt
Keyword(s):  
Electron Microscopy ◽  
Thin Section ◽  
Unknown Function ◽  
Inclusion Bodies ◽  
Cellular Material ◽  
Alpha Particles ◽  
Partial Characterization ◽  
Thin Sections ◽  
Pressure Cell

Polyhedral inclusion bodies (alpha particles) of unknown function have been observed previously in T. neopolitanus by electron microscopy of thin sections. Partial characterization of these bodies has been accomplished by means of rate-zonal centrifugation. The cells were broken by a French pressure cell, treated with deoxyribonuclease prior to centrifugation.Figure 1 is a thin section of T. neopolitanus showing bacteria with varying numbers of alpha particles.Initial attempts were made to isolate the intact alpha particles by ratezonal and isopycnic methods in both swinging bucket and zonal rotors. Nevertheless, the alpha particles were usually contaminated with membrane fragments and other cellular material as well as inner components (alpha particles) from partially ruptured alpha particles, as shown in Fig. 2.

Micromorphological evidence of pedogenetic pathway of a Podzolic Gray Luvisol (Falmouth series) in Nova Scotia

1995 ◽  
Vol 75 (4) ◽  
pp. 491-496 ◽  
Author(s):  
C. Wang ◽  
G. R. Brewster ◽  
K. T. Webb
Keyword(s):  
Organic Matter ◽  
Nova Scotia ◽  
Key Words ◽  
Thin Sections ◽  
Parent Materials ◽  
Acidic Nature ◽  
Gray Luvisol ◽  
Bt Horizon

A catena of Podzolic Gray Luvisols (Falmouth series) – Gleyed Gray Luvisols (Queens series) – Orthic Gleysols (Kingsville series) is commonly found on fine loamy, weakly calcareous parent materials in Nova Scotia, with Podzolic Gray Luvisols occupying the best drained landscape positions. The hypothesis that podzolic B horizons of Podzolic Gray Luvisols were developed on degraded Bt horizons was investigated by micromorphological characterization of one Podzolic Gray Luvisol pedon. Although not visible in field examinations, argillans were common in thin sections of the Bf and Bm horizons. These argillans were not associated with the walls of voids or the surface of grains. Argillans of the Bt horizons, however, were associated with features such as cracks, vughs, and channels. The upper Bt horizon (i.e., Bt1gj) showed signs of degradation. The pale brown matrix color was more like the Bm horizon above than the dark brown Bt2gj horizon below. The strongly acidic nature of the Bt1gj horizon may have triggered degradation. It is concluded that the Bf and Bm horizons were developed on degraded Bt horizons through the translocation of amorphous Fe and Al and organic matter. Key words: Pedogenesis, micromorphology, Luvisols, bisequal soils

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.

A TEM study of the interface between organic matrix and aragonite in a biological hard tissue, nacre

1992 ◽  
Vol 50 (2) ◽  
pp. 1024-1025
Author(s):  
Jun Liu ◽  
Katie E. Gunnison ◽  
Mehmet Sarikaya ◽  
Ilhan A. Aksay
Keyword(s):  
Mechanical Properties ◽  
Ion Beam ◽  
Laminated Composite ◽  
Organic Matrix ◽  
Pearl Oyster ◽  
Interfacial Structure ◽  
Interfacial Region ◽  
Thin Sections ◽  
Organic Layers ◽  
Transmission Electron

The interfacial structure between the organic and inorganic phases in biological hard tissues plays an important role in controlling the growth and the mechanical properties of these materials. The objective of this work was to investigate these interfaces in nacre by transmission electron microscopy. The nacreous section of several different seashells -- abalone, pearl oyster, and nautilus -- were studied. Nacre is a laminated composite material consisting of CaCO3 platelets (constituting > 90 vol.% of the overall composite) separated by a thin organic matrix. Nacre is of interest to biomimetics because of its highly ordered structure and a good combination of mechanical properties. In this study, electron transparent thin sections were prepared by a low-temperature ion-beam milling procedure and by ultramicrotomy. To reveal structures in the organic layers as well as in the interfacial region, samples were further subjected to chemical fixation and labeling, or chemical etching. All experiments were performed with a Philips 430T TEM/STEM at 300 keV with a liquid Nitrogen sample holder.

Stability of bounded rapid shear flows of a granular material

1996 ◽  
Vol 308 ◽  
pp. 31-62 ◽  
Author(s):  
Chi-Hwa Wang ◽  
R. Jackson ◽  
S. Sundaresan
Keyword(s):  
Growth Rate ◽  
Stability Analysis ◽  
Granular Material ◽  
Bulk Density ◽  
Particulate Material ◽  
Dominant Mode ◽  
Marginal Stability ◽  
Sheared Layer ◽  
The Stability ◽  
Unusual Type

This paper presents a linear stability analysis of a rapidly sheared layer of granular material confined between two parallel solid plates. The form of the steady base-state solution depends on the nature of the interaction between the material and the bounding plates and three cases are considered, in which the boundaries act as sources or sinks of pseudo-thermal energy, or merely confine the material while leaving the velocity profile linear, as in unbounded shear. The stability analysis is conventional, though complicated, and the results are similar in all cases. For given physical properties of the particles and the bounding plates it is found that the condition of marginal stability depends only on the separation between the plates and the mean bulk density of the particulate material contained between them. The system is stable when the thickness of the layer is sufficiently small, but if the thickness is increased it becomes unstable, and initially the fastest growing mode is analogous to modes of the corresponding unbounded problem. However, with a further increase in thickness a new mode becomes dominant and this is of an unusual type, with no analogue in the case of unbounded shear. The growth rate of this mode passes through a maximum at a certain value of the thickness of the sheared layer, at which point it grows much faster than any mode that could be shared with the unbounded problem. The growth rate of the dominant mode also depends on the bulk density of the material, and is greatest when this is neither very large nor very small.

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.

Effect of forest harvesting and slash piling on microbial biomass and respiration in Newfoundland boreal forests

2007 ◽  
Vol 87 (4) ◽  
pp. 455-458 ◽  
Author(s):  
Martin T Moroni ◽  
Paul Q Carter ◽  
Dean W Strickland ◽  
Franz Makeschin ◽  
Don-Roger Parkinson ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Key Words ◽  
Boreal Forests ◽  
Fungal Biomass ◽  
Forest Harvesting ◽  
Organic Layer ◽  
Total Microbial Biomass ◽  
Organic Layers ◽  
Respiration Rates ◽  
Fumigation Extraction

Clearcutting Newfoundland boreal forests significantly reduced organic layer fungal and total microbial biomass in clearcut areas with and without slash cover, compared with forested plots. However, aerobically incubated respiration rates were highest in organic layers from clearcut areas under slash, intermediate under forests, and lowest from clearcut areas without slash. Key words: Carbon, ergosterol, fumigation–extraction, fungal biomass, harvest slash, nitrogen

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