Electron microprobe analysis of the distribution of silicon in the leaves of Selaginella emmeliana

1980 ◽  
Vol 58 (23) ◽  
pp. 2459-2466 ◽  
Author(s):  
Nancy G. Dengler ◽  
Eric Y-C. Lin
Keyword(s):  
Electron Microscopy ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Cell Types ◽  
Preliminary Survey ◽  
Leaf Epidermis ◽  
Abaxial Side ◽  
X Ray ◽  
Tangential Wall ◽  
Scanning Electron

Scanning electron microscopy and X-ray microanalysis of the ventral leaves of Selaginella emmeliana demonstrated high levels of silicon in the marginal sclereids and about one-half the abaxial epidermal cells. Although both of these cell types bear rows of knobs or warts on the outer tangential wall, the X-ray spectra indicate that silicon is distributed throughout the wall and that it is not concentrated in these projections. In S. emmeliana, stomata are confined to a band of low silicon cells overlying the midrib on the abaxial side of the leaf. A small proportion of these stomata also contain high levels of silicon and are characterized by a constricted stomatal aperture. A preliminary survey of three other species of Selaginella indicates that accumulation of silicon in the leaf epidermis is characteristic for each.

scholarly journals Efflorescent Sulfate Crystallization on Fractured and Polished Colloform Pyrite Surfaces: A Migration Pathway of Trace Elements

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 12
Author(s):  
Dimitrina Dimitrova ◽  
Vassilka Mladenova ◽  
Lutz Hecht
Keyword(s):  
Electron Microscopy ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
X Ray ◽  
Inductively Coupled ◽  
Migration Pathway ◽  
Plasma Mass Spectrometry ◽  
Scanning Electron

The colloform pyrite variety incorporates many trace elements that are released in the environment during rapid oxidation. Colloform pyrite from the Chiprovtsi silver–lead deposit in Bulgaria and its oxidation efflorescent products were studied using X-ray diffractometry, scanning electron microscopy, electron microprobe analysis, and laser ablation inductively coupled plasma mass spectrometry. Pyrite is enriched with (in ppm): Co (0.1–964), Ni (1.8–3858), Cu (2.9–3188), Zn (3.1–77), Ag (1.2–1771), As (8179–52,787), Se (2.7–21.7), Sb (48–17792), Hg (4–2854), Tl (1.7–2336), Pb (13–7072), and Au (0.07–2.77). Gypsum, anhydrite, szomolnokite, halotrichite, römerite, copiapite, aluminocopiapite, magnesiocopiapite, coquimbite, aluminocoquimbite, voltaite, and ammoniomagnesiovoltaite were identified in the efflorescent sulfate assemblage. Sulfate minerals contain not only inherited elements from pyrite (Cr, Fe, Co, Ni, Cu, Zn, Ag, In, As, Sb, Hg, Tl, and Pb), but also newly introduced elements (Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Mn, Ga, Rb, Sr, Y, Zr, Sn, Cs, Ba, REE, U, and Th). Voltaite group minerals, copiapite, magnesiocopiapite, and römerite incorporate most of the trace elements, especially the most hazardous As, Sb, Hg, and Tl. Colloform pyrite occurrence in the Chiprovtsi deposit is limited. Its association with marbles would further restrict the oxidation and release of hazardous elements into the environment.

scholarly journals How Microanalysis Can Be Discriminant on Black Pompeian Wares

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 879
Author(s):  
Laura Medeghini ◽  
Silvano Mignardi ◽  
Giorgia Di Fusco ◽  
Michela Botticelli ◽  
Fulvio Coletti ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Analytical Approach ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Specific Production ◽  
X Ray ◽  
Black Layer ◽  
Scanning Electron

In the present work the advantages of punctual approaches are discussed in the discrimination of black wares from the Sanctuary of Venus Fisica (Pompeii, Italy), dated between the 2nd and 1st century BC. Black-gloss ware and "bucchero" samples are analyzed by a multi-analytical approach including optical microscopy (OM), X-ray powder diffraction (XRPD), scanning electron microscopy with Energy Dispersive Spectroscopy (SEM-EDS) and electron microprobe analysis (EMPA) to investigate the mineralogical and petrographic features of these artefacts. Grain size, firing conditions and potter’s expertise influenced the final appearance of the superficial decorative black layer. In addition, punctual chemical analysis was fundamental to verify the archaeological indication of specific production sites.

A Study of Natural Metamict Yttrium Niobate as Analogue of Actinide Ceramic Waste Form

2014 ◽  
Vol 1665 ◽  
pp. 313-318 ◽  
Author(s):  
Cao Qiuxiang ◽  
Anton I. Isakov ◽  
Liu Xiaodong ◽  
Sergey V. Krivovichev ◽  
Boris E. Burakov
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Single Phase ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Original Sample ◽  
X Ray Diffraction ◽  
Average Chemical Composition ◽  
X Ray ◽  
Scanning Electron

ABSTRACTNatural metamict mineral found as large (1-3 cm in size) homogeneous grains (as assumed, former single crystals), was investigated by X-ray powder diffraction (pXRD), high-temperature pXRD, scanning electron microscopy (SEM) and electron microprobe analysis (EMPA). The average chemical composition obtained by EMPA is (wt. %): Nb2O5 – 42.6; Ta2O5 – 4.4; TiO2 – 9.2; UO3 – 4.4; ThO2 – 1.0; MnO – 1.3; FeO – 19.4; Y2O3 – 16.6.The untreated (original) sample is X-ray amorphous. The sample remained amorphous after annealing at 400 °C for 1 hour. The sample became almost fully crystalline after annealing at 700 °C for 1 hour with an X-ray diffraction pattern similar to that of Fe-columbite (ICCD: 01-074-7356). Further annealing at 1000 °C and higher temperatures caused changes in the phase composition of the sample. It was proposed that under self-irradiation a single-phase U-Th-bearing solid solution, based on monocrystalline Y-niobate, became metamict but remained homogeneous without evidence of solid solution destruction. However, this metamict solid solution is unstable under thermal treatment and recrystallization.

scholarly journals Aqua Traiana, a Roman Infrastructure Embedded in the Present: The Mineralogical Perspective

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 703
Author(s):  
Michela Botticelli ◽  
Laura Calzolari ◽  
Caterina De Vito ◽  
Silvano Mignardi ◽  
Laura Medeghini
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Building Materials ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Construction Materials ◽  
Petrographic Analysis ◽  
X Ray ◽  
Selection Of ◽  
Scanning Electron

Construction materials from the internal ducts of Aqua Traiana, a still operative Roman aqueduct built in 109 AD to supply water to Rome, were characterized by optical microscopy (OM), scanning electron microscopy (SEM-EDS), X-ray powder diffraction (XRPD) and electron microprobe analysis (EMPA). Petrographic analysis and XRPD revealed that mortar aggregates are compatible with Vitruvius’ harena fossicia and allowed the distinction of the original mortars from those of the 17th-century papal restoration. The first showed an amorphous binder while the latter have a typical lime binder. By SEM-EDS and EMPA, the microstructure of mortar aggregates was analyzed and the composition of specific minerals quantified. Microanalysis testifies the Romans’ great expertise in the selection of pozzolanic building materials, giving evidence of the possible use of local tuffs from the Sabatini Volcanic District. It also confirms the exploitation of red pozzolan from the Roman Magmatic Province, specifically from the Alban Hills district. OM also proves a high compatibility with local supplies for bricks and cocciopesto. Of these, the first were fired at moderately low temperature, while the latter show an amorphous binder as in the original Trajan mortars. All building materials thus stand for similar technological choices and a coeval production.

Scanning Electron Microscopy and Electron Microprobe Analysis of Malignant Cell Cultures

1968 ◽  
Vol 26 ◽  
pp. 164-165
Author(s):  
R. I. Johnsson-Hegyeli ◽  
A. F. Hegyeli ◽  
D. K. Landstrom ◽  
W. C. Lane
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Cultures ◽  
Electron Microprobe ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Three Dimensional ◽  
Malignant Cell ◽  
Interference Microscopy ◽  
Scanning Electron

Last year we reported on the use of reflected light interference microscopy (RLIM) for the direct color photography of the surfaces of living normal and malignant cell cultures without the use of replicas, fixatives, or stains. The surface topography of living cells was found to follow underlying cellular structures such as nuceloli, nuclear membranes, and cytoplasmic organelles, making possible the study of their three-dimensional relationships in time. The technique makes possible the direct examination of cells grown on opaque as well as transparent surfaces. The successful in situ electron microprobe analysis of the elemental composition and distribution within single tissue culture cells was also reported.This paper deals with the parallel and combined use of scanning electron microscopy (SEM) and the two previous techniques in a study of living and fixed cancer cells. All three studies can be carried out consecutively on the same experimental specimens without disturbing the cells or their structural relationships to each other and the surface on which they are grown. KB carcinoma cells were grown on glass coverslips in closed Leighto tubes as previously described. The cultures were photographed alive by means of RLIM, then fixed with a fixative modified from Sabatini, et al (1963).

Jahnsite—whiteite solid solutions and associated minerals in the phosphate pegmatite at Hagendorf-Süd, Bavaria, Germany

2010 ◽  
Vol 74 (6) ◽  
pp. 969-978 ◽  
Author(s):  
I. E. Grey ◽  
W. G. Mumme ◽  
S. M. Neville ◽  
N. C. Wilson ◽  
W. D. Birch
Keyword(s):  
Electron Microscopy ◽  
Solid Solutions ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Full Range ◽  
Intensity Data ◽  
Compositional Zoning ◽  
Phosphate Mineral ◽  
End Members ◽  
Scanning Electron

AbstractSecondary phosphate assemblages from the Hagendorf Süd granitic pegmatite, containing the new Mn-Al phosphate mineral, nordgauite, have been characterized using scanning electron microscopy and electron microprobe analysis. Nordgauite nodules enclose crystals of the jahnsite—whiteite group of minerals, showing pronounced compositional zoning, spanning the full range of Fe/Al ratios between jahnsite and whiteite. The whiteite-rich members are F-bearing, whereas the jahnsite-rich members contain no F. Associated minerals include sphalerite, apatite, parascholzite, zwieselite-triplite solid solutions and a kingsmountite-related mineral. The average compositions of whiteite and jahnsite from different zoned regions correspond to jahnsite-(CaMnMn), whiteite-(CaMnMn) and the previously undescribed whiteite-(CaMnFe) end-members. Mo-Kα CCD intensity data were collected on a twinned crystal of the (CaMnMn)-dominant whiteite and refined in P2/a to wRobs = 0.064 for 1015 observed reflections.

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