Density and loss on ignition as indicators of the fossilization of silicified wood

IAWA Journal ◽  
2016 ◽  
Vol 37 (1) ◽  
pp. 98-111 ◽  
Author(s):  
George E. Mustoe
Keyword(s):  
Electron Microscopy ◽  
Weight Loss ◽  
Organic Matter ◽  
Polarized Light ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laboratory Facilities ◽  
Hydrous Silica ◽  
Original Organic Matter

Measuring density of silicified wood and determining weight loss after 450°C heating provides useful data for interpreting the process of permineralization. These simple gravimetric methods do not replace X-ray diffraction, electron microscopy, polarized light microscopy, Raman spectroscopy, and other specialized techniques for studying fossil wood, but they can be performed rapidly, and require minimal laboratory facilities. Woods mineralized with opal have densities of 1.9–2.1 g/cm3, compared to 2.3–2.6 g/cm3 for wood mineralized with chalcedony or quartz. Weight loss after 450°C heating, commonly described as “loss on ignition” can be used to roughly estimate the % of original organic matter that remains in chalcedony or quartz-mineralized wood, using the density of extant taxa for comparison. For opalized wood, 450°C weight loss mostly represents dehydration of the hydrous silica. Data from specimens from 20 localities reveal two characteristics: 1) silicified woods typically consist either of opal or chalcedony/quartz, not an intermediate mixture of the two silica polymorphs; 2) the percentage of organic matter that remains after petrifaction is usually very small.

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.

Preparation of Construction Bricks from Iron Ore Tailings

2012 ◽  
Vol 557-559 ◽  
pp. 839-844 ◽  
Author(s):  
Gao Xiang Du ◽  
Ran Fang Zuo ◽  
Wei Juan Guo ◽  
Jing Hui Liao
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Iron Ore ◽  
Sintering Temperature ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Ore Tailings ◽  
Scanning Electron

Based on the background that large amount of iron ore tailings are stockpiled in China, the utilization of iron ore tailings to prepare sintering brick was studied. The main objective of this paper was to investigate the influence of sintering temperature on sintering bricks from iron ore tailings, in the presence of clay, coal refuses and bentonite. Sintering bricks were prepared at different temperature with 40 wt% iron ore tailings. Drying was investigated as well as the loss on ignition, bulk density and compressive strength of the specimens. Their mechanical and microstructure properties were also investigated by radioactivity, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the specimens produced were higher than that required by the standards MU20 of GB5101-2003, up to 128.0Mpa at 1100°C corresponding to its higher bulk density completely.

Preparation and Properties of Sintering Brick from Iron Tailings

2012 ◽  
Vol 512-515 ◽  
pp. 1023-1027
Author(s):  
Ran Fang Zuo ◽  
Gao Xiang Du ◽  
Le Fu Mei ◽  
Wei Juan Guo ◽  
Jing Hui Liao
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Raw Materials ◽  
Loss On Ignition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Freeze Thaw ◽  
Scanning Electron

The main objective of this paper was to investigate the addition of iron tailing sintering brick production, in the presence of clay, coal refuses and bentonite. Mixtures containing raw materials of sintering brick and iron tailings were prepared at different proportions (up to 55 wt %), fired at 980°C. Freeze/thaw durability, drying and firing shrinkages were investigated as well as the loss on ignition, bulk density and compressive strength of the fired samples. Their mechanical and microstructure properties were also investigated by differential thermal analysis (DTA/TG), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results showed that compressive strengths of the brick samples are higher than that required by the standards MU15 of GB5101-2003, up to 21.79Mpa with 40% iron tailings corresponding to its higher bulk density completely. Moreover, the results showed that it has such advantages as no lime blowing, uniform color, good freeze/thaw resistance and slight universal frost.

Clay minerals in the Namacotche Pegmatite Group from Zambezia Province, Mozambique: main constituents of late-stage secondary paragenesis

Clay Minerals ◽  
2008 ◽  
Vol 43 (4) ◽  
pp. 597-613 ◽  
Author(s):  
M. A. Sequeira Braga ◽  
C. Leal Gomes ◽  
J. Duplay ◽  
H. Paquet
Keyword(s):  
Electron Microscopy ◽  
Clay Minerals ◽  
Late Stage ◽  
Polarized Light ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Close Relationship ◽  
Xrd Patterns

AbstractNamacotche gem-bearing pegmatites of Alto Ligonha pegmatite district are heterogeneous, strongly fractionated, and have large Li and Ta and extremely large Cs contents. Clay samples were collected in fracture infillings and dilation cavities with gemstones and were studied using X-ray diffraction (XRD), polarized light microscope, scanning electron microscopy-energy dispersive spectroscopy, high-resolution transmission electron microscopy and chemical analyses. The <2 μm fraction contains cookeite, illite, illite-smectite and suggested irregular mixed-layer cookeite-smectite, beidellite, montmorillonite, kaolinite and goethite.The XRD patterns of chlorite and their d values suggest the presence of ‘di-trioctahedral chlorite’ similar to cookeite-Ia polytype. Cookeite chemical analyses show that Li contents range from 0.82 to 1.08 atoms per half unit cell.A close relationship has been established between occurrences of gemstones and clay minerals. Some important textures and crystal chemistry are discussed.The main gemstones related to the Namacotche Pegmatite are: morganite (pink cesian beryl), kunzite (spodumene) and elbaite tourmaline. As the mechanisms responsible for the gemstone formation take place at low temperature, the clay minerals paragenesis cookeite ± cookeite-smectite interstratification ± beidellite + montmorillonite ± illite-smectite interstratification, represents a late-stage secondary paragenesis, generated by hydrothermal alteration.

scholarly journals Advanced Characterization of Organic Matter Decaying during Composting of Industrial Waste Using Spectral Methods

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1364
Author(s):  
Saloua Biyada ◽  
Mohammed Merzouki ◽  
Hamada Imtara ◽  
Mohamed F. Alajmi ◽  
Karima Elkarrach ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Organic Matter ◽  
Microbiological Analysis ◽  
Least Squares Regression ◽  
X Ray Diffraction ◽  
Compost Maturity ◽  
X Ray ◽  
Physical Chemical ◽  
Scanning Electron

To date, compost maturation monitoring is carried out by physical-chemical and microbiological analysis, which could be considered an overweening consumption of time and products. Nowadays, spectroscopy is chosen as a simple tool for monitoring compost maturity. In the present investigation, spectroscopy analysis was performed in the interest of corroborating the compost maturity. This goal was achieved by using the X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. X-ray diffraction analysis showed the presence of the cellulose fraction in compost samples. At the same time, the intensity of pics decreased depending on composting time, thus proving that there was organic matter degradation. Infrared and scanning electron microscopy analysis allow for confirming these results. The correlation between spectroscopies analysis and physical-chemical properties was employed by partial least squares-regression (PLS-R) model. PLS-R model was applied to build a model to predict the compost quality depending on the composting time, the results obtained show that all the parameters analysis are well predicted. The current study proposed that final compost was more stabilized compared with the initial feedstock mixture. Ultimately, spectroscopy techniques used allowed us to confirm the physical-chemical results obtained, and both of them depict maturity and stability of the final compost, thus proving that spectral techniques are more reliable, fast, and promising than physical-chemical analyses.

Biomorphous Porous Carbon Prepared from Cotton Stalk

2012 ◽  
Vol 253-255 ◽  
pp. 871-874
Author(s):  
Qing Wang ◽  
Xi Cheng ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Weight Loss ◽  
Porous Carbon ◽  
Cotton Stalk ◽  
Pyrolysis Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Structures ◽  
Scanning Electron

The biomorphic porous carbon was prepared by high temperature pyrolysis at 1000oC. The pyrolysis process of cotton stalk was measured by thermogravimetric analysis (TG). The morphology and microstructure of carbon were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. As compared with the dried cotton stalk, the carbon has an anisotropic shrinkage with 20–40% and about 80% weight loss. The carbon retains the tubular cell structures.

Effects of selected bleaching agents on the functional and structural properties of orange albedo starch-based bioplastics

2020 ◽  
Vol 40 (2) ◽  
pp. 120-128
Author(s):  
Adewale G. Adeniyi ◽  
Oluwaseyi D. Saliu ◽  
Joshua O. Ighalo ◽  
Adebayo I. Olosho ◽  
Deborah T. Bankole ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Weight Loss ◽  
Sodium Perborate ◽  
X Ray Diffraction ◽  
Flow Properties ◽  
X Ray ◽  
Infrared Scanning ◽  
Wide Range ◽  
Scanning Electron

AbstractRecent research has proven that starch offers a wide range of industrial, commercial, and utility applications if they are optimally processed and refined. In this study, the effect of hydrogen peroxide (HP), sodium persulfite, peracetic acid (PAA), and sodium perborate (SPB) bleaching agents on the physiochemical, surface, mechanical, and flow properties were investigated. The various bleached starch bioplastics were characterized using Fourier transform infrared, scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. Hydroxyl and carbonyl (C=O) stretching were seen for HP- and PAA-bleached starch bioplastics at 3285 and 1736 and 3265 and 1698 cm−1, respectively. The C=O band was absent for SPB-treated starch, whereas the C=S band was seen on sodium hyposulfite (SHS)-treated starch. The morphologies of starch were retained with little agglomerations, except for HP-treated starch bioplastics with a morphology change. HP-treated starch had the highest percentage crystallinity (66%) and the highest thermal stability (74% weight loss), whereas PAA-treated starch had the lowest percentage crystallinity (34%) and the lowest thermal stability (88% weight loss). HP- and SHS-bleached starch bioplastics had the best surface, mechanical, and expansion properties.

Electron Microscopy of Human Gallstones

1971 ◽  
Vol 29 ◽  
pp. 296-297
Author(s):  
C. Wolpers ◽  
R. Blaschke
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Bile Pigment ◽  
X Ray Diffraction ◽  
Triclinic Crystal System ◽  
X Ray ◽  
Follow Up Study ◽  
Infra Red ◽  
Main Components

Scanning microscopy was used to study the surface of human gallstones and the surface of fractures. The specimens were obtained by operation, washed with water, dried at room temperature and shadowcasted with carbon and aluminum. Most of the specimens belong to patients from a series of X-ray follow-up study, examined during the last twenty years. So it was possible to evaluate approximately the age of these gallstones and to get information on the intensity of growing and solving.Cholesterol, a group of bile pigment substances and different salts of calcium, are the main components of human gallstones. By X-ray diffraction technique, infra-red spectroscopy and by chemical analysis it was demonstrated that all three components can be found in any gallstone. In the presence of water cholesterol crystallizes in pane-like plates of the triclinic crystal system.

Electron Microscopy of Shock Loaded Polycrystalline Beryllium

1974 ◽  
Vol 32 ◽  
pp. 506-507 ◽  
Author(s):  
J. M. Galbraith ◽  
L. E. Murr ◽  
A. L. Stevens
Keyword(s):  
Electron Microscopy ◽  
Wave Propagation ◽  
Structural Change ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Shock Loading ◽  
Slip Systems ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray

Uniaxial compression tests and hydrostatic tests at pressures up to 27 kbars have been performed to determine operating slip systems in single crystal and polycrystal1ine beryllium. A recent study has been made of wave propagation in single crystal beryllium by shock loading to selectively activate various slip systems, and this has been followed by a study of wave propagation and spallation in textured, polycrystal1ine beryllium. An alteration in the X-ray diffraction pattern has been noted after shock loading, but this alteration has not yet been correlated with any structural change occurring during shock loading of polycrystal1ine beryllium.This study is being conducted in an effort to characterize the effects of shock loading on textured, polycrystal1ine beryllium. Samples were fabricated from a billet of Kawecki-Berylco hot pressed HP-10 beryllium.

Freeze-Fracture Replication of Frozen Outer Segments of Rat Retinal Rods

1969 ◽  
Vol 27 ◽  
pp. 392-393
Author(s):  
Thomas S. Leeson ◽  
C. Roland Leeson
Keyword(s):  
Electron Microscopy ◽  
Cross Section ◽  
Outer Segment ◽  
Freeze Fracture ◽  
X Ray Diffraction ◽  
X Ray ◽  
Outer Segments ◽  
Retinal Rods ◽  
Temperature Electron ◽  
Freeze Etching

Numerous previous studies of outer segments of retinal receptors have demonstrated a complex internal structure of a series of transversely orientated membranous lamellae, discs, or saccules. In cones, these lamellae probably are invaginations of the covering plasma membrane. In rods, however, they appear to be isolated and separate discs although some authors report interconnections and some continuities with the surface near the base of the outer segment, i.e. toward the inner segment. In some species, variations have been reported, such as longitudinally orientated lamellae and lamellar whorls. In cross section, the discs or saccules show one or more incisures. The saccules probably contain photolabile pigment, with resulting potentials after dipole formation during bleaching of pigment. Continuity between the lamina of rod saccules and extracellular space may be necessary for the detection of dipoles, although such continuity usually is not found by electron microscopy. Particles on the membranes have been found by low angle X-ray diffraction, by low temperature electron microscopy and by freeze-etching techniques.

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