DIAMANTES EM DEPÓSITOS COLUVIONARES DO TAPAJÓS (ITAITUBA, PARÁ)

2021 ◽  
Vol 8 (2021) (2) ◽  
pp. 1-41
Author(s):  
Marcus Brito ◽  
◽  
Marcondes Costa ◽  
Herbert Pöllmann ◽  
Mário Chaves ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Amazon Region ◽  
Average Weight ◽  
X Ray Diffraction ◽  
Mato Grosso ◽  
X Ray ◽  
Scanning Electron

The diamonds from the Painin garimpo, on the Tapajós River, in Itaituba, state of Pará, were mined in alluvial gravel in geological terrains dominated by the Barreirinha, Itaituba and Monte Alegre Paleozoic formations. 30 diamonds extracted from the concentrates of this garimpo were analyzed by stereomicroscopy, optical microscopy, x-ray diffraction, scanning electron microscopy with EDS and luminescence. The average weight of these specimens is 0.42 ct and the predominant forms are dodecahedral and octahedral, in addition to others such as ballas and bort. Surface figures, microstructures, luminescence, and various inclusions are recognized. The inclusions can be classified as syngenetic (periclase, diopside, among others) and epigenetic (eg minerals of crandallite group). Green covers were also observed. This study, however, was not able to solve the problem of the genesis of the diamond in the studied region, as happens to date with most secondary diamond deposits in the Amazon region (Tapajós, Tocantins and Tepequém-Maú), except for those related to kimberlite pipes of Mato Grosso Rondônia.

Microstructural Evaluation of Clayey Ceramic Incorporated with Sludge from Paper Manufacturing

2016 ◽  
Vol 881 ◽  
pp. 422-426
Author(s):  
Carlos Maurício Fontes Vieira ◽  
Regina Maria Pinheiro ◽  
Sergio Neves Monteiro
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Paper Making ◽  
Paper Manufacturing ◽  
Microstructural Evaluation ◽  
Calcium Compounds ◽  
Scanning Electron

This work has for objective to evaluate the microstructure of clayey ceramic incorporated with a waste in the form of sludge generated during treatment of effluent of a paper making industry. The microstructure of ceramics incorporated with 0 and 10 wt.% of waste, and then fired at 600°C, was evaluated by optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that the waste changes the microstructure of the clayey ceramic increasing the porosity, as well as forming new crystalline phases, mainly with calcium compounds.

Processing of Biodegradable Polymer Composite Using Soy Protein-Based Resin and Nanoclay

2016 ◽  
Author(s):  
Mohammad K. Hossain ◽  
Samira N. Shaily ◽  
Hadiya J. Harrigan ◽  
Terrie Mickens
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Soy Protein ◽  
Poly Vinyl Alcohol ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

A completely biodegradable composite was fabricated from an herbal polymer, soy protein concentrate (SPC) resin. Soy protein was modified by adding 30 wt% of glycerol and 5 wt% of poly vinyl alcohol (PVA) to enhance its mechanical as well as thermal property. 3%, 5%, 10%, and 20% nanoclay (NC) were infused into the system. To evaluate its mechanical properties, crystallinity, thermal properties, bonding interaction, and morphological evaluation, tensile, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) tests, and optical microscopy (OM) and scanning electron microscopy (SEM) evaluation were performed. Tensile tests showed that the addition of nanoclay improved the mechanical properties of the modified resin. Soy protein is hydrophilic due to the presence of amino acids that contain various polar groups such as amine, carboxyl, and hydroxyl. As a result, polar nanoclay particles that are exfoliated can be evenly dispersed in the SPC resin. From experimental results, it is clear that adding of nanoclay with SPC resin significantly increased the stiffness of the SPC resin. A combination of 5% clay, 30% glycerol, and 5% PVA with the modified SPC resulted in the maximum stress of 18 MPa and Young modulus of 958 MPa. The modified SPC showed a reduced failure strain as well. X-ray diffraction curves showed an improvement of crystallinity of the prepared resin with increasing amount of nanoclay. Interaction among soy, glycerol, PVA, and nanoclay was clearly demonstrated from the FTIR analysis. Optical microscopy (OM) and scanning electron microscopy (SEM) micrographs revealed rougher surface in the nanoclay infused SPC samples compared to that of the neat one. SEM evaluation revealed rougher fracture surface in the NC infused samples.

Electro-Less Ni-P Plating Coating of In Situ TiCp/Al-4.5wt.%Cu Vomposites

2015 ◽  
Vol 817 ◽  
pp. 593-598
Author(s):  
Yan Feng Liang ◽  
Sheng Quan Dong ◽  
Gao Hong Li
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Citric Acid ◽  
Optical Microscopy ◽  
X Ray Diffraction ◽  
Citric Acid Concentration ◽  
X Ray ◽  
In Situ Tic ◽  
Scanning Electron

In situ TiCp/Al-4.5wt.%Cu composites have been coated using an electro-less Ni-P plating technique. The morphology and composition of the plating coating have been examined by scanning electron microscopy, optical microscopy, and X-ray diffraction. The results indicated that the coating had a high-phosphorus amorphous microstructure. The coatings microstructures showed significantly changes when the citric acid concentration in the chemical bath was varied in the range 16-20g/L.

Partitioning of Cesium in Phases Produced by Grouted Waste Injection

1983 ◽  
Vol 26 ◽  
Author(s):  
D. P. Stinton ◽  
E. W. Mcdaniel ◽  
H. O. Weerent
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stable Cesium ◽  
The Core ◽  
Calcium Silicates ◽  
Hydrated Calcium ◽  
Scanning Electron

ABSTRACTPhases present in injected grouts were characterized by use of optical microscopy, scanning electron microscopy, x-ray diffraction, and β-γ autoradiography. A laboratoryproduced sample containing 1 wt % stable cesium and an actual grout sheet obtained by core drilling were examined. The phases present in these samples were identified, and cesium was found to be absorbed almost entirely by illite clay agglomerates. These clay agglomerates were tightly bound within the grout structure by hydrated calcium silicates. The β-γ autoradiography of the core-drilled sample verified that cesium and other radionuclides were trapped within the 20-year-old grout and had not migrated into trapped shale fragments.

ANALYTICAL INVESTIGATIONS ON A FIRED STUCCO WINDOW IN THE ISLAMIC ART MUSEUM STORE OF CAIRO, EGYPT

2021 ◽  
Vol 21 (3) ◽  
pp. 789-806
Author(s):  
MONA F. ALI ◽  
HALA A. M. AFIFI ◽  
AML M. LOTFY
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Infrared Spectroscopy ◽  
Optical Microscopy ◽  
Art Museum ◽  
Islamic Art ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The stucco window in this study is kept in the stores of the Museum of Islamic Art in Cairo, Egypt, and bears the number 454/7. This window has been exposed to many damage factors, the most important of which is the fire that broke out in the museum in 2006 AD, in addition to the effect of the water that was used to extinguish the fire. This research aims to study the components of the window (stucco - glass - wood) and identify the transformations resulting from the effect of fire using optical microscopy, scanning electron microscopy coupled with EDX, X-ray diffraction, and infrared spectroscopy. In addition, the microbiological damage resulting from the moisture that saturates the plaster and wood was investigated.

Morphology Control of Sulfide in Fe-Cr-S alloys during the solidification

1999 ◽  
Vol 580 ◽  
Author(s):  
Katsunari Oikawa ◽  
Tamio Ikeshoji ◽  
Hajime Mitsui ◽  
Kiyohito Ishida
Keyword(s):  
Electron Microscopy ◽  
Phase Diagram ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Fine Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cr Content ◽  
Morphology Changes ◽  
Scanning Electron

AbstractThe evolution of sulfide morphology in the Fe- (0.3 to 18) mass% Cr -0.3 mass% S alloys during solidification and its modification by additions of elements such as Mn, Ti, Zr and C have been investigated by means of optical microscopy, scanning electron microscopy and X-ray diffraction. The sulfide morphologies in the Fe-Cr-S ternary alloy are classified under three types: (i) cellwall (ii) fine particle and (iii) globular sulfides. The iron-rich cellwall sulfide is formed in the Fe-(0.3-1) %Cr-0.3 %S alloys. This sulfide morphology changes to the globular type with increasing Cr content and the size of that is more than 51gm. Fine sulfide particles of size smaller than 2 gtm also coexist in the Fe-(0.3-5) %Cr-0.3 %S alloys. Zr or Ti additions change this morphology from the globular type to the rod-like type in the Fe-18 %Cr-0.3 %S alloy, but Mn addition does not have the same effect. The mechanism of the formation of different sulfide morphologies is discussed on the basis of phase diagram information.

Structure and Composition of Rhinoceros Horn

1992 ◽  
Vol 292 ◽  
Author(s):  
Ann Chidester Van Orden ◽  
Joseph C. Daniel
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Breeding Success ◽  
The Other ◽  
X Ray Diffraction ◽  
Structural Morphology ◽  
X Ray ◽  
Metal Ceramic ◽  
Scanning Electron

AbstractRhinoceros horn has been used medicinally and as a talisman in many cultures and animals are slaughtered to obtain the horn. With the dwindling populations of rhinos, and the limited number and breeding success of captive rhinos, there is a critical need to learn as much as is possible about their horns to find an adequate substitute. Examination of rhino horn was made using optical microscopy, scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDS), and x-ray diffraction (XRD). The structure of the horn is unusual and consists of two separate phases, one of hair-like filaments, built around a central core in circumferential layers and the other surrounding and filling in the spaces between the filaments as a matrix. Together, these two structures make up a biological composite, structurally similar to metal, ceramic or polymer based composites. The structural morphology, the dimensions of the structures, and the chemistry of the horn are discussed. Comparisons are made between horn, hoof, and hair of rhinos and hoof and hair from horses, their nearest living relatives.

AMORPHIZATION OF CERIUM MONONITRIDE DURING OXIDIZATION CHARACTERIZED BY OPTICAL MICROSCOPY, SCANNING ELECTRON MICROSCOPY, X-RAY DIFFRACTION AND X-RAY PHOTOELECTRON SPECTROSCOPY

2019 ◽  
Vol 26 (04) ◽  
pp. 1850180
Author(s):  
WEI LIANG ◽  
QIFA PAN ◽  
YIN HU ◽  
LIZHU LUO ◽  
KEZHAO LIU ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Optical Microscopy ◽  
Photoelectron Spectroscopy ◽  
Ion Beam ◽  
Film Surface ◽  
Ambient Atmosphere ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Cerium mononitride (CeN) film was fabricated by dual ion beam sputtering deposition method on silicon wafer. The oxidization process of CeN film was monitored by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), respectively. The results showed that, when the CeN film was exposed to ambient atmosphere, bubbles appeared on the film surface rapidly and then the surface flaked off to powders. Meanwhile, the CeN film changed from polycrystalline to amorphous. XPS analysis indicated that the CeN was oxidized to Ce2O3 initially, and then further oxidized to CeO2. These results indicated that the CeN film degraded easily in ambient atmosphere, exhibiting little or no passivation.

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.

Environmental scanning electron microscopy of fresh human gallstones reveals new morphologies of precipitated calcium salts

1992 ◽  
Vol 50 (2) ◽  
pp. 1322-1323
Author(s):  
Howard S. Kaufman ◽  
Keith D. Lillemoe ◽  
John T. Mastovich ◽  
Henry A. Pitt
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
X Ray Diffraction ◽  
Calcium Salts ◽  
Cholesterol Gallstones ◽  
X Ray ◽  
Ca Carbonate ◽  
Scanning Electron

Gallstones contain precipitated cholesterol, calcium salts, and proteins. Calcium (Ca) bilirubinate, palmitate, phosphate, and carbonate occurring in gallstones have variable morphologies but characteristic windowless energy dispersive x-ray (EDX) spectra. Previous studies of gallstone microstructure and composition using scanning electron microscopy (SEM) with EDX have been limited to dehydrated samples. In this state, Ca bilirubinates appear as either glassy masses, which predominate in black pigment stones, or as clusters, which are found mostly in cholesterol gallstones. The three polymorphs of Ca carbonate, calcite, vaterite, and aragonite, have been identified in gallstones by x-ray diffraction, however; the morphologies of these crystals vary in the literature. The purpose of this experiment was to study fresh gallstones by environmental SEM (ESEM) to determine if dehydration affects gallstone Ca salt morphology.Gallstones and bile were obtained fresh at cholecystectomy from 6 patients. To prevent dehydration, stones were stored in bile at 37°C. All samples were studied within 4 days of procurement.

Sign in / Sign up

Export Citation Format

Share Document