Wood Petrifaction: and aspect of biomineralogy

1979 ◽  
Vol 27 (4) ◽  
pp. 377 ◽  
Author(s):  
G Scurfield
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
X Ray Diffraction ◽  
Intercellular Substance ◽  
X Ray ◽  
Colloidal Form ◽  
Cell Lumina ◽  
Mineral Deposition ◽  
Wall Components ◽  
Scanning Electron

Light microscopy, scanning electron microscopy, X-ray diffraction and differential thermal analysis have been used to examine the structure and mineralogical make-up of 79 Australian petrified woods. Initiation of petrifaction appears to rely on the provision of a substrate with inherent porosity, with the substrate components chemically rather inert and only slowly degraded at normal temperatures and pressures under conditions probably most often acid and tending to anaerobic, and the pores sufficiently large to allow access of an appropriate mineral in ionic or colloidal form in water. Stages in the process include entry of mineral solution into the wood via splits or checks, cell lumina, and other voids; permeation of cell walls; progressive dissolution of cell wall components beginning largely with lignin and accompanied by a build-up of a mineral framework adequate for maintaining the dimensional stability of the wood; mineral deposition in cell lumina after cell wall replacement as a continuous, intermittent, perhaps separate, but not obligatory event; mineral deposition in voids present or formed by dissolution of intercellular substance as a separate, but not obligatory event; and final lithification involving loss of water and perhaps replacement of one mineral by another.

The effects of thermal treatment on the nanomechanical behavior of bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) cell walls observed by nanoindentation, XRD, and wet chemistry

Holzforschung ◽  
2017 ◽  
Vol 71 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Yanjun Li ◽  
Chengjian Huang ◽  
Li Wang ◽  
Siqun Wang ◽  
Xinzhou Wang
Keyword(s):  
Cell Wall ◽  
Thermal Treatment ◽  
Cell Walls ◽  
Treatment Time ◽  
Lignin Content ◽  
Phyllostachys Pubescens ◽  
X Ray Diffraction ◽  
Wet Chemistry ◽  
X Ray ◽  
Wet Chemical

Abstract The effects of thermal treatment of bamboo at 130, 150, 170, and 190°C for 2, 4, and 6 h were investigated in terms of changes in chemical composition, cellulose crystallinity, and mechanical behavior of the cell-wall level by means of wet chemical analysis, X-ray diffraction (XRD), and nanoindentation (NI). Particularly, the reduced elastic modulus (Er), hardness (H), and creep behavior were in focus. Both the temperature and treatment time showed significant effects. Expectedly, the hemicelluloses were degraded and the relative lignin content was elevated, while the crystallinity of the cellulose moiety was increased upon thermal treatment. The Er and H data of the cell wall were increased after 6 h treatment at 190°C, from 18.4 to 22.0 GPa and from 0.45 to 0.65 GPa, respectively. The thermal treatment led to a decrease of the creep ratio (CIT) under the same conditions by ca. 28%. The indentation strain state (εi) also decreased significantly after thermal treatment during the load-holding stage.

Osmium Staining Fails to Detect Early Cell Wall Damage in Brown Rot Wood Decay

IAWA Journal ◽  
1994 ◽  
Vol 15 (2) ◽  
pp. 133-136
Author(s):  
W. Wayne Wilcox
Keyword(s):  
Cell Wall ◽  
Electron Microscope ◽  
Cell Walls ◽  
Osmium Tetroxide ◽  
Wood Decay ◽  
Brown Rot ◽  
X Ray ◽  
Polarised Light ◽  
Early Manifestation ◽  
Scanning Electron

Loss of cell wall birefringence under polarised light in the light microscope is an important diagnostic characteristic for early stages of brown rot wood decay not available with the scanning electron microscope (SEM). Osmium tetroxide staining was explored as a means of visualising this early manifestation of decay in the SEM, but proved unsuccessful as X-ray spectroscopy indicated that osmium was evenly distributed across both distorted and non-distorted cell walls.

Metallography, Microanalysis & Corrosion of the Athlit Ram

2011 ◽  
Vol 1319 ◽  
Author(s):  
M. R. Notis ◽  
M. Hoban ◽  
D-N. Wang
Keyword(s):  
Electron Microscopy ◽  
Cell Walls ◽  
Optical Metallography ◽  
Metal Corrosion ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Matrix ◽  
Wood Analysis ◽  
Maritime Museum ◽  
Scanning Electron

ABSTRACTThe Athlit ram, a bronze warship ram from a 2nd Century BCE Roman-era galley, was found in 1980 off the coast of Israel at Athlit, and is now displayed at the National Maritime Museum, Haifa, Israel. It meant to fit on the prow of a medium-sized oared warship. This ram is the only known surviving example of this ancient naval weapon. Inside the bronze ram some of the ship’s wood is still preserved. We have recently studied a piece of the ram removed during early conservation. Remnant metal, corrosion products, and mineralized and pseudomorphed wood have all been found and examined by light optical metallography, x-ray diffraction, scanning electron microscopy, and microanalysis using energy dispersive x-ray mapping. The main corrosion product on the Athlit Ram is identified as covellite (CuS), and the entrained material is pseudomorphed cedar wood. Analysis indicates the lumen to be replaced by calcium carbonate and the cell walls to be replaced by covellite, consistent with the matrix.

Structure of chitin in the cell walls of newly formed and mature conidia of Fusarium sulphureum

1982 ◽  
Vol 28 (5) ◽  
pp. 531-535 ◽  
Author(s):  
E. F. Schneider ◽  
W. L. Seaman
Keyword(s):  
Cell Wall ◽  
Acetic Acid ◽  
Cell Walls ◽  
Molecular Hydrogen ◽  
Spectroscopic Analysis ◽  
Conidiogenous Cell ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Fusarium Sulphureum

Samples of 7-day-old septate conidia (mature conidia) and newly released aseptate ones (immature conidia) of Fusarium sulphureum were hydrolyzed successively in KOH, acetic acid – H2O2, and H2SO4. The cell wall residue of the mature conidia remained intact throughout the hydrolysis but that of immature conidia dissolved in the H2SO4. Thus, the immature conidial cell wall is substantially different from that of mature conidial cells or growing hyphae and the cell wall undergoes a structural transformation following conidium release from the conidiogenous cell. X-ray diffraction analyses of the wall residues following KOH and acetic acid – H2O2 hydrolysis showed that the mature conidial wall residue had a crystalline chitin component, while the residue of the immature conidial wall was more amorphous and had smaller crystals. An X-ray diffraction pattern of the dissolved immature conidial wall that was recovered from the H2SO4 hydrolysate showed that it contained crystalline chitin.Infrared spectroscopic analysis of the mature conidial cell wall residue showed absorption bands due to inter- and intra-molecular hydrogen bonding and for hydrogen stretching associated with crystalline chitin. Such bands were lacking in the immature cell wall analogue.

Structure and composition of the cell wall of Choanephora cucurbitarum

1976 ◽  
Vol 22 (4) ◽  
pp. 486-494 ◽  
Author(s):  
D. R. Letourneau ◽  
J. M. Deven ◽  
M. S. Manocha
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Free Cell ◽  
Infrared Spectrophotometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
Neutral Sugars ◽  
Choanephora Cucurbitarum ◽  
Hyphal Wall

Mechanically isolated, cytoplasm-free cell walls of Choanephora cucurbitarum were analyzed qualitatively and quantitatively by use of microchemical methods, infrared spectrophotometry, and X-ray diffraction. Chemical analysis of cell wall revealed the presence of chitin (17%), chitosan (28.4%), neutral sugars (7.2%), uronic acid (2.4%), proteins (8.2%), and lipids (13.8%). The structure of hyphal wall, investigated by electron microscopy of shadowed replicas before and after alkali-acid hydrolysis, showed two distinct regions: microfibrillar and amorphous. The microfibrils, which were composed of mainly chitin, were organized into two distinct layers; an outer, thicker layer of randomly oriented microfibrils, and an inner, thin layer of parallel microfibrils. In its structure and chemical composition the cell wall of C. cucurbitarum resembles those of other zygomycetous fungi.

scholarly journals The structure of the cell wall in some species of the filamentous green alga Cladophora

1940 ◽  
Vol 129 (854) ◽  
pp. 54-76 ◽  
Keyword(s):  
Cell Wall ◽  
Green Alga ◽  
Cell Elongation ◽  
Cell Walls ◽  
Opposite Sign ◽  
Periodic Change ◽  
X Ray Diffraction ◽  
X Ray ◽  
Filamentous Green Alga ◽  
Flat Spiral

With a view to extending the work on Valonia , the cell walls of several species of Cladophora have been examined in detail by means of X-ray diffraction photographs and the microscope. The walls are found to consist of layers in which the cellulose chains in any one layer are inclined to those in the preceding and subsequent layers at an angle whose average is less than 90°. The two sets of striations on the layers of the wall correspond closely to the directions of the cellulose chains. Each set of chains forms a spiral round the cell, and the spirals are of opposite sign. One tends to be flat and th e other steep. On the whole, th e steep spiral tends to become steeper on passing from the base of the filament to the tip, and the flat spiral flatter. In any one cell of the filament, the steep spiral is steepest at the end nearer the filament tip and the flat spiral flattest. Wherever such changes in inclination occur, the angle between the chains tends to remain constant. It is suggested that cell elongation is the factor causing the inclination of the steeper spiral to vary, and that the behaviour of the flatter spiral is best explained by the assumption of a protoplasmic mechanism causing a periodic change in the direction of cellulose chains through a constant angle. The development of a branch cell is reviewed and is found to proceed as the above suggestions would indicate.

Biocrystallization of mineral material on forage plant cell walls

1979 ◽  
Vol 30 (4) ◽  
pp. 635 ◽  
Author(s):  
WR McManus ◽  
RG Anthony ◽  
LL Grout ◽  
AS Malin ◽  
VNE Robinson
Keyword(s):  
Cell Wall ◽  
General Pattern ◽  
Cellulose Fibre ◽  
X Ray Diffraction ◽  
Plant Materials ◽  
X Ray ◽  
Transmission Electron ◽  
Mineral Deposition ◽  
Major Increase ◽  
Calcium And Phosphorus

Seventeen mature roughage plant materials (10 grasses, 7 legumes) were chemically analysed for cell wall content and other fractions. The nature and distribution of the less soluble mineral depositions found on structural elements of the mature plants was investigated by means of X-ray diffraction and electron optical techniques. Energy-dispersive X-ray analysis of the ash fractions of the dry matter (DM), cell wall (cw) and acid detergent matter (ADM) of five grasses, and of the DM of three legumes, the cw of five legumes and the ADM of two legumes, showed the plant structures examined to be highly mineralized. DM, cw and ADM fractions showed different patterns of mineralization. Within each chemical fraction fibres had elemental compositions similar to those found in general fields of the same fraction. This suggests that a general pattern of mineral deposition occurs during plant growth. Cell wall ash fractions of both grasses and legumes were shown to be relatively high in calcium and phosphorus and, in the case of grasses, silicon. Following acid detergent extraction, there was a major increase in the amount of silicon underlying the calcium and phosphorus-rich (and, in grasses, silicon-rich) hemicellulose fraction. Examination of the cellulose fibre matter of lucerne and of wheat straw after potassium permanganate extraction but not ashing showed silicon to be the dominant element in the external layer. Eight plant roughages, yielding 20 specimen fractions (cw, ADM, lignin) were examined by X-ray diffraction. Four plant cw materials were examined by transmission electron microscopy. At least two crystalline forms of calcium and phosphorus, hydroxylapatite and Whitlockite, were shown to exist in cw ash. α-Quartz, in rod and tube-like structures, was also identified in cw ash and ADM ash. These findings are discussed in terms of the concept of the plant as a solar still.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

Identification of calcium oxalate crystals in dried or fixed tobacco leaf

1984 ◽  
Vol 42 ◽  
pp. 288-289
Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Calcium Oxalate ◽  
Growth And Development ◽  
Polarized Light ◽  
Calcium Oxalate Crystals ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

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