Characterization of Individual Airborne Particles by Light Microscopy, Electron and Ion Probe Microanalysis, And Electron Microscopy

Author(s):  
M. Grasserbauer
Author(s):  
George Guthrie ◽  
David Veblen

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).


Chromosoma ◽  
2005 ◽  
Vol 115 (1) ◽  
pp. 50-59 ◽  
Author(s):  
Elizabeth Schroeder-Reiter ◽  
Andreas Houben ◽  
Jürke Grau ◽  
Gerhard Wanner

Author(s):  
Reyes Peña-Santiago ◽  
Marcel Ciobanu ◽  
Joaquin Abolafia

Several populations of four known species of the genus Pungentus (P. clavatus, P. engadinensis, P. marietani and P. silvestris), collected in the wild and in cultivated soils from the Iberian Peninsula, are studied. Detailed redescriptions and morphometrics are presented for each species. Illustrations are provided, including line drawings, light microscopy pictures of the four species as well as scanning electron microscopy observations of P. engadinensis. The Iberian populations are compared to type and other known populations, and new data are given that provide a better characterization of these taxa. Pungentus engadinensis is the most widely distributed species in the Iberian Peninsula.


Author(s):  
Richard E. Crang

Acid resistant components of the pollen wall and tapetal membrane in flowering plants have long been known to be composed of sporopollenin—a highly resistant mixture of organic compounds. Recent light microscopy and cytochemical analyses have led to the recognition that additional organic compounds comprise a significant part of these anther structures. However, comparatively little consideration has been given to the inorganic composition of the pollen exine and the morphologically similar tapetal membrane. Electron microscopy allows the morphological characterization of components and, when coupled with energy dispersive x-ray analysis, offers the opportunity to characterize elemental composition.


2017 ◽  
Vol 4 (2) ◽  
Author(s):  
Gabriele Patricia Vitoria da Silva ◽  
Bruna Tereza Possamai ◽  
Gabriel da Rosa Schroeder ◽  
Nilton Paulo Vieira Junior ◽  
Enderlei Dec ◽  
...  

Clerodendrum splendens A. Chev., Clerodendrum x speciosum Tiej. & Binn, Clerodendrum thomsonae Balf. F., Clerodendrum ugandense L., Congea tomentosa Roxb., Duranta erecta L., Petrea volubilis L. and Petrea volubilis f. albiflora (Standl.) Standl. pollen grains were acetolyzed, photographed and measured under light microscopy and scanning electron microscopy. Values presented are averages in micrometers. Grains are monads, radially symmetrical, isopolar, large (C. ugandense, very large, C. tomentosa, small-medium and D. erecta, medium),tricolpate (P. volubilis f. albiflora, dimorphic grains with 3-4 colpus). Ambitus is circular (C. tomentosa and D. erecta, sub-circular, P. volubilis , triangular, P. volubilis f. albiflora, triangular-quadrangular). The form is oblate-spheroidal (C. splendens, C. x speciosum, C. ugandense), prolate-spheroidal (C. thomsonae), prolate (C. tomentosa), suboblate (D. erecta) and oblate (P. volubilis, P. volubilis f. albiflora). Exine thickness is in C. splendens 4,28, C. x speciosum 4,19, C. ugandense 4,33, C. thomsonae 4,18, C. tomentosa 1,4, D. erecta 1,55, P. volubilis 2,49, P. volubilis f. albiflora 2,68. Ornamentation is micro-echinate (C. splendens, C. x speciosum, C. thomsonae), echinate (C. ugandense), reticulate (C. tomentosa), psilate (D. erecta, P. volubilis, P. volubulis f. albiflora). Duranta and Petrea are close to Verbenaceae pattern, Congea to Lamiaceae and Clerodendrum loosely to Lamiaceae.


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