scholarly journals Study of the Behavior of Gold and Accompanying Chemical Elements in Weathering Profile on a Quartz Vein in Mintom (South Cameroon, Central Africa)

2021 ◽  
Vol 10 (2) ◽  
pp. 54
Author(s):  
Aurélien Manfred Mbenoun ◽  
Gilbert François Ngon Ngon ◽  
Michel Bertrand Mbog ◽  
Rose Yongeu Fouateu ◽  
Paul Bilong
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Quartz Vein ◽  
Chemical Elements ◽  
Central Africa ◽  
Sem Analysis ◽  
Heavy Minerals ◽  
Gold Particles ◽  
Free Particles ◽  
Scanning Electron

The present study, which focuses on the behavior of gold and its accompanying chemical elements developed on an alteration profile, is carried out in a humid equatorial zone at Mintom in South Cameroon (Central Africa). The methodology used to achieve the results obtained focused on the description of the morphology of the outcrop, the petrography of the rock studied, the study of heavy minerals accompanying gold in the weathering materials on smear slides, mineralogical analysis of weathering materials by X-ray diffraction (XRD), scanning electron microscopy (SEM) analysis of gold and geochemical analyzes by ICP - AES and ICP - MS of weathering materials. The main results obtained from this methodology inform us that on the petrographic level the main rock studied is the gold-bearing quartz vein located in Zom, consisting mainly of quartz and opaque minerals. Morphologically, the weathering materials developed on this granite basement present an advanced ABC-type profile characterized by a significant thickness (4 to 6 m). The morphological and chemical characters of the gold particles have evolved from the mineralized zone to the surface. This development was marked by an increase in blunt, rounded grains. Morphoscopy and scanning electron microscopy of the gold particles have shown hollow, blunt to sub-blunt grains, non-evolved free particles, and evolved free particles, respectively. In most samples of weathered material gold is found in association with chemical elements such as Ag, Cr, Co, Cu, Ni, V and figure 10 show identical behavior between these chemical elements and gold, but particularly between silver and gold, which would testify to an identical origin. Au concentrations are very high in most samples of weathering material. Also, these samples of altered materials with a high proportion of gold (0.01 to 2.28 ppm) also present high concentrations of silver (Ag) which justifies that the occurrence or the gold deposit is associated with silver and can be exploited as a geochemical parameter to prospect for gold in the study area.

SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

Environmental Scanning Electron Microscopy Technique to Identify Asbestos Phases Inside Ferruginous Bodies

2013 ◽  
Vol 19 (2) ◽  
pp. 420-424 ◽  
Author(s):  
Alessandro Croce ◽  
Maya Musa ◽  
Mario Allegrina ◽  
Paolo Trivero ◽  
Caterina Rinaudo
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Elements ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Thin Sections ◽  
The Core ◽  
Microscopy Technique ◽  
Ferruginous Bodies ◽  
Scanning Electron

AbstractFerruginous bodies observed in lungs of patients affected by mesothelioma, asbestosis, and pulmonary carcinoma are important to relate the illness to exposure, environmental or occupational, to asbestos. Identification of the inorganic phase constituting the core of the ferruginous bodies, formed around asbestos but also around phases different from asbestos, is essential for legal purposes. Environmental scanning electron microscopy/energy dispersive spectroscopy was used to identify the fibrous mineral phase in the core of ferruginous bodies observed directly in thin sections of tissue, without digestion of the biological matrix. Spectra were taken with sequential analyses along a line crossing the core of the ferruginous bodies. By comparing the spectra taken near to and far from the core, the chemical elements that make up the core could be identified.

Development of Alginate Based Active Films Containing Turmeric Essential Oil

2020 ◽  
Vol 861 ◽  
pp. 378-382
Author(s):  
Sophoan Phal ◽  
Muhammad Rafiullah Khan ◽  
Pattarin Leelaphiwat ◽  
Vanee Chonhenchob
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Water Vapor ◽  
Essential Oil ◽  
Sem Analysis ◽  
Film Properties ◽  
Elongation At Break ◽  
Control Film ◽  
Scanning Electron

Sodium alginate based films containing turmeric oil (TEO) at different concentrations (1, 2 and 3%) were developed. The film with no TEO was used as control. Incorporation of TEO had the effects on the film properties. With increasing TEO concentrations, thickness, elongation at break, permeability of oxygen and water vapor of the films significantly (p ≤ 0.05) increased. Whereas moisture content, tensile strength and modulus of elasticity significantly (p ≤ 0.05) decreased. Scanning electron microscopy (SEM) analysis showed more numerous pores and rougher surface of the antifungal films than the control film.

Deepwater sculpin, Myoxocephalus thompsoni (Girard) from a Pleistocene nodule, Green Creek, Ontario, Canada

1979 ◽  
Vol 16 (8) ◽  
pp. 1621-1628 ◽  
Author(s):  
Donald E. Champagne ◽  
C. R. Harington ◽  
Don E. McAllister
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Habitat Preferences ◽  
Sem Analysis ◽  
Lake Basin ◽  
Lacustrine Environment ◽  
Clay Matrix ◽  
Summer Temperatures ◽  
Scanning Electron ◽  
Ultraviolet Lamp

A nodule containing the cranium of a deepwater sculpin, Myoxocephalus thompsoni (Girard), was discovered in Pleistocene Champlain Sea deposits at Green Creek, 10 km east of Ottawa, Ontario, Canada, and represents the first fossil reported for the species. It provides an additional basis for refuting derivation of the species from a post-Wisconsin marine submergence and suggests an origin at the beginning of the Wisconsin or earlier. Habitat preferences of the species favour an oligotrophic lacustrine environment with bottom summer temperatures below 8 °C in the Champlain Sea or nearby lake basin. The head length of the fossil is 28 mm, the estimated standard length 86 mm. Use of a longwave ultraviolet lamp with the fossil improved contrast between the bones and the clay matrix in photographs. Scanning electron microscopy (SEM) analysis of bone in the fossil failed to detect the presence of strontium.

scholarly journals Effective diameters of protein A-gold and goat anti-rabbit-gold conjugates visualized by field emission scanning electron microscopy.

1992 ◽  
Vol 40 (6) ◽  
pp. 751-758 ◽  
Author(s):  
P Lea ◽  
D K Gross
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Field Emission ◽  
Gold Particle ◽  
Protein A ◽  
Gold Complexes ◽  
Gold Particles ◽  
Gold Particle Size ◽  
Scanning Electron

High-voltage (15-30 kV) field emission scanning electron microscopy (FESEM) was used to evaluate the effects of gold particle size and protein concentration on the formation of protein-gold complexes. Six colloidal gold sols were prepared, ranging in diameter from 7.6 to 39.8 nm. The minimal protecting amounts (m.p.a.) of protein A and goat anti-rabbit antibody (GAR) were experimentally determined. Gold particles were conjugated at the m.p.a., one half the m.p.a., and ten times the m.p.a. for both proteins, and protein-gold complexes prepared for FESEM. The smallest colloidal gold particles required the most protein per milliliter of gold suspension for stabilization. Transmission electron microscopy was found to be the preferred method for accurate sizing of gold particles, whereas FESEM of protein-gold complexes permitted visualization of a protein halo around a spherical gold core. Protein halo width varied significantly with changes in gold particle size. Measurements of protein halos indicated that conjugation with the m.p.a. of protein A resulted in the thickest protein layers for all gold sizes. GAR conjugation with the m.p.a. again produced the thickest protein layers. However, GAR halos were significantly smaller than those obtained with protein A conjugation. The proteins used showed similar adsorption patterns for the larger gold particles. For smaller gold particles, proteins may act differently, and these complexes should be further characterized by low-voltage FESEM.

Morphology of Lignin-Polyurethane Blends

1989 ◽  
Vol 153 ◽  
Author(s):  
D. Feldman ◽  
M.A. Lacasse
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Sem Analysis ◽  
Accelerated Weathering ◽  
Dsc Analysis ◽  
Mechanical Mixing ◽  
Scanning Calorimetry ◽  
Two Phases ◽  
Scanning Electron

AbstractThe morphology of blended polyurethane (PU) sealants was studied by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The PU was modifided by mechanical mixing with various amounts of Lignin (L) to achieve a homogeneous blend. Specimens were subjected to control (C), accelerated weathering (AW), and natural weathering (NW) conditions. Results obtained from SEM analysis reveal an even distribution of L particles in the PU matrix. Furthermore, the SEM photomicrographs clearly emphasize the differing morphologies of the constituent phases. They also depict the differences in surface texture between control and aged specimens. The DSC analysis shows that the two phases are immiscible which is in agreement with observations by microscopy.

scholarly journals Ecological and micromorphological research of soils of the central floodplain of the Samara river

2014 ◽  
Vol 15 (3-4) ◽  
pp. 89-99
Author(s):  
O. V. Strizhak
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Soil Profile ◽  
Chemical Elements ◽  
Pore Space ◽  
Chip Surface ◽  
Secondary Electrons ◽  
Thin Sections ◽  
Electron Mode ◽  
Scanning Electron

The influence of environmental factors on the formation of microforms typical for soils of the central river floodplain Samara and mechanisms of formation of the soil profile have been considered. The attention is paid to the identification and soil genesis of cutana. To achieve the goals the micromorphological research methods and techniques of scanning electron microscopy have been used. The decoding of soil thin sections has been carried out in the standard scheme. The relief of chip surface was studied in the secondary electrons, the homogeneity of the distribution of chemical elements - by the surface of the secondary electrons, the chemical composition of the studied surface areas was received by a microroentgen-spectral analysis. The studies have shown the main features in the microstructure of these soils. In the profile the microstructure is inhomogeneous, in the upper horizons is silty-plasma, changes with the depth to sand-plasma and in the lower horizons – plasma-sand. The skeleton grains are characterized by the following transfer on their surface (scratches) and by a good roundness. Plasma is humus-clay, with the depth the clayey plasma decreases. It is typical for the clay part of the plasma two refractive indices, the orientation and the ability to restructure. The pore space is the most developed in the upper horizons, thanks to digging activity of earthworms. With the depth the pore area decreases and often the pore walls cover with clayey cutanas for the illuvial processes. As a result of intensive impacts of nutrient factors, the upper horizons are well-structured. In each profile you can select several kaprolit horizons. For this kind of profile the humus mull is more typical. Kutana complex is represented by clay cutana. In the upper horizons they are poorly expressed, are not present in all pores. Down to the profile their quantity in the pores increases, they become more pronounced. The explanation of the chip surface using a scanning electron microscopy confirmes the mobility of plasma and illuvial origin of cutana. The data obtained in the secondary electron mode and microanalysis shows the monotony of addition with minor bright zones which belongs to titanium or chromium-containing minerals. The features of the microstructure of the soil profile in central floodplain are conditioned by the floodplain processes. With the reduction of their influence, because of the increase between the periods of flood and their intensity, the forming role of biological factors increases.

Interaction of Al-Si Alloys with SiC/C Ceramic Particles and their Influence on Microstructure of Composites

2011 ◽  
Vol 176 ◽  
pp. 55-62 ◽  
Author(s):  
Anna J. Dolata
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Chemical Composition ◽  
Chemical Analysis ◽  
Chemical Elements ◽  
Chemical Compositions ◽  
Structural Studies ◽  
Liquid Aluminium ◽  
Ceramic Particles ◽  
Scanning Electron

Interaction of Al-Si alloys with SiC/C ceramic particles and their influence on microstructure of composites was discussed. This article presents a significant effect of modifying additives introduced into liquid aluminium. As it was shown in the research, Mg and Sr modifiers improve wetting conditions in Al/SiCp+Cp systems, as well as influence the composite’s structure and the structure of the interface between the components. The microstructure observations were performed using light microscopy (OLYMPUS GX 71) and scanning electron microscopy (PHILIPS XL30). Moreover, local analyses of chemical compositions as well as chemical elements mapping were performed using an EDX module for microarea chemical analysis. Based on structural studies, it was found that chemical composition of the aluminium alloy and its modification are equally important parameters.

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