scholarly journals Low Temperature Illitization through Illite-Dioctahedral Vermiculite Mixed Layers in a Tropical Saline Lake Rich in Hydrothermal Fluids (Sochagota Lake, Colombia)

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 523
Author(s):  
Gabriel Ricardo Cifuentes ◽  
Juan Jiménez-Millán ◽  
Claudia Patricia Quevedo ◽  
Fernando Nieto ◽  
Javier Cuadros ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Organic Matter ◽  
Low Temperature ◽  
High Salinity ◽  
Source Rocks ◽  
Temperate Climate ◽  
Lake Basin ◽  
X Ray ◽  
Saline Waters ◽  
Mixed Layers

In this investigation, we showed that high salinity promoted by hydrothermal inputs, reducing conditions of sediments with high content in organic matter, and the occurrence of an appropriate clay mineral precursor provide a suitable framework for low-temperature illitization processes. We studied the sedimentary illitization process that occurs in carbonaceous sediments from a lake with saline waters (Sochagota Lake, Colombia) located at a tropical latitude. Water isotopic composition suggests that high salinity was produced by hydrothermal contribution. Materials accumulated in the Sochagota Lake’s southern entrance are organic matter-poor sediments that contain detrital kaolinite and quartz. On the other hand, materials formed at the central segment and near the lake exit (north portion) are enriched in organic matter and characterized by the crystallization of Fe-sulfides. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray spectrometry (EDX) data allowed for the identification of illite and illite-dioctahedral vermiculite mixed layers (I-DV), which are absent in the southern sediments. High humidity and temperate climate caused the formation of small-sized metastable intermediates of I-DV particles by the weathering of the source rocks in the Sochagota Lake Basin. These particles were deposited in the low-energy lake environments (middle and north part). The interaction of these sediments enriched in organic matter with the saline waters of the lake enriched in hydrothermal K caused a reducing environment that favored Fe mobilization processes and its incorporation to I-DV mixed layers that acted as mineral precursor for fast low temperature illitization, revealing that in geothermal areas clays in lakes favor a hydrothermal K uptake.

Magnesium Nitrate as Additive for Synthesis of Mg(OH)2 Nanoparticles

2012 ◽  
Vol 198-199 ◽  
pp. 99-102
Author(s):  
Qing Gang Kong ◽  
Hai Yan Qian
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Magnesium Nitrate ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Size And Morphology ◽  
Scanning Electron

Magnesium nitrate was used as additive for synthesis of Mg(OH)2 (MH) nanoparticles at low temperature (70°C). Mg(OH)2 nanoparticles have platelet-like structure and approximately 40-60nm in thicknesses. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were applied to characterize the crystal phase. The supersaturation degree of solution effects the size and morphology of MH nanoparticles.

Intrinsic non-stoichiometry and anomalous transport properties of layered oxysulfide LaOPbBiS3

2021 ◽  
Author(s):  
Céline Roux-Byl ◽  
David Berardan
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Transport Properties ◽  
Anomalous Transport ◽  
Fluorine Doping ◽  
X Ray Diffraction ◽  
X Ray

We report on the intrinsic non-stoichiometry and the influence of fluorine doping on the low temperature transport properties of layered oxysulfide LaOPbBiS3. From X-ray diffraction coupled to electron microscopy studies,...

SiO2ZrO2 Thin Films as Low Temperature NO2 and O3 Sensors

2015 ◽  
Vol 1088 ◽  
pp. 81-85 ◽  
Author(s):  
T.N. Myasoedova ◽  
Victor V. Petrov ◽  
Nina K. Plugotarenko ◽  
Dmitriy V. Sergeenko ◽  
Galina Yalovega ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Scanning Electron Microscopy ◽  
Low Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Operating Temperatures ◽  
Scanning Electron

Thin SiO2ZrO2films were prepared, up to 0.2 μm thick, by means of the sol–gel technology and characterized by a Scanning electron microscopy and X-ray diffraction. It is shown the presence of monoclinic, cubic and tetragonal phases of ZrO2in the SiO2matrix. The crystallites sizes depend on the annealing temperature of the film and amount to 35 and 56 nm for the films annealed at 773 and 973 K, respectively. The films resistance is rather sensitive to the presence of NO2and O3impurity in air at lower operating temperatures in the range of 30-60°C.

MOCVD ZnS:Mn Films: Grain Size Distribution and Crystal Structure as a Function of the Growth Parameters

2001 ◽  
Vol 672 ◽  
Author(s):  
Kathleen A. Dunn ◽  
Katharine Dovidenko ◽  
Anna W. Topol ◽  
Serge R. Oktyabrsky ◽  
Alain E. Kaloyeros
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Grain Size ◽  
Low Temperature ◽  
Film Thickness ◽  
Growth Parameters ◽  
X Ray Diffraction ◽  
Direction Parallel ◽  
X Ray ◽  
Average Grain Size

ABSTRACTZinc sulfide doped with manganese is extensively used for thin film electroluminescent device applications. In order to assess the key material and process challenges, ZnS:Mn layers were fabricated by metalorganic chemical vapor deposition in the 250°-500°C range on an AlTiO/InSnO/glass stack. The microstructure of the ZnS:Mn films was examined by Transmission Electron Microscopy (TEM) as part of a larger study which fully characterizes these films by a variety of structural and chemical characterization techniques, including Rutherford Backscattering, Secondary Ion Mass Spectroscopy, Atomic Force Microscopy, Scanning Electron Microscopy and X-ray Diffraction. For all the growth conditions, the films were found to be polycrystalline having predominantly 2H hexagonal ZnS structure. The ZnS grains are found to grow columnar as the film thickness increases, also widening in the direction parallel to the substrate surface and reaching the 100 - 200 nm average lateral size at the 650 nm film thickness. The presence of the 8H ZnS polytype was detected in the low-temperature ZnS:Mn films by TEM selected area electron diffraction and confirmed by X-ray diffraction analysis. Dark field TEM imaging correlated this 8H ring with very small (∼2.5 nm) grains present throughout the low temperature film with a slightly higher density at the film/substrate interface. The 700°C post-deposition annealing was found to initiate a solid state transformation to the cubic (3C) ZnS crystal structure, and resulted in an average grain size of ∼250 nm at the surface of the annealed film.

Low-temperature instability of Ti2SnC: A combined transmission electron microscopy, differential scanning calorimetry, and x-ray diffraction investigations

2009 ◽  
Vol 24 (1) ◽  
pp. 39-49 ◽  
Author(s):  
J. Zhang ◽  
B. Liu ◽  
J.Y. Wang ◽  
Y.C. Zhou
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Low Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Temperature Instability ◽  
X Ray ◽  
Transmission Electron ◽  
Ceramic Microstructure

Transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and x-ray diffraction (XRD) investigations were conducted on the hot-pressed Ti2SnC bulk ceramic. Microstructure features of bulk Ti2SnC ceramic were characterized by using TEM, and a needle-shaped β-Sn precipitation was observed inside Ti2SnC grains with the orientation relationship: (0001) Ti2SnC // (200) Sn and Ti2SnC // [001] Sn. With the combination of DSC and XRD analyses, the precipitation of metallic Sn was demonstrated to be a thermal stress-induced process during the cooling procedure. The reheating temperature, even as low as 400 °C, could trigger the precipitation of Sn from Ti2SnC, which indicated the low-temperature instability of Ti2SnC. A substoichiometry Ti2SnxC formed after depletion of Sn from ternary Ti2SnC phase. Under electron beam irradiation, metallic Sn was observed diffusing back into Ti2SnxC. Furthermore, a new Ti7SnC6 phase with the lattice constants of a = 0.32 and c = 4.1 nm was identified and added in the Ti-Sn-C ternary system.

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.

Mineralization of Sialoliths Investigated by Ex Vivo and In Vivo X-ray Computed Tomography

2019 ◽  
Vol 25 (1) ◽  
pp. 151-163 ◽  
Author(s):  
Pedro Nolasco ◽  
Paulo V. Coelho ◽  
Carla Coelho ◽  
David F. Angelo ◽  
J. R. Dias ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Computed Tomography ◽  
Organic Matter ◽  
Ex Vivo ◽  
Correct Selection ◽  
Quantitative Relation ◽  
Helical Computed Tomography ◽  
X Ray ◽  
X Ray Computed

AbstractThe fraction of organic matter present affects the fragmentation behavior of sialoliths; thus, pretherapeutic information on the degree of mineralization is relevant for a correct selection of lithotripsy procedures. This work proposes a methodology for in vivo characterization of salivary calculi in the pretherapeutic context. Sialoliths were characterized in detail by X-ray computed microtomography (μCT) in combination with atomic emission spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Correlative analysis of the same specimens was performed by in vivo and ex vivo helical computed tomography (HCT) and ex vivo μCT. The mineral matter in the sialoliths consisted essentially of apatite (89 vol%) and whitlockite (11 vol%) with average density of 1.8 g/cm3. In hydrated conditions, the mineral mass prevailed with 53 ± 13 wt%, whereas the organic matter, with a density of 1.2 g/cm3, occupied 65 ± 10% of the sialoliths’ volume. A quantitative relation between sialoliths mineral density and X-ray attenuation is proposed for both HCT and μCT.

A Novel Low-Temperature-Fired Multifunctional Varistor-Magnetic Ferrite Materials

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000641-000649
Author(s):  
Li-Then Mei ◽  
Hsing-I Hsiang ◽  
Hui-Wen Ye
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Grain Boundary ◽  
Schottky Barriers ◽  
Energy Dispersion Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
Donor Dopant ◽  
Type Semiconductor ◽  
The Relationship

A novel low temperature-fired (950°C) multifunctional varistor-magnetic ferrite materials can be obtained by adding V2O5 into CuCr0.2Fe1.8O4 ferrites. The relationship between the grain-boundary composition and varistor properties were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersion spectroscopy (EDS), and X-ray photoelectric spectroscopy (XPS). The addition of V2O5 can effectively reduce the sintering temperature of CuCr0.2Fe1.8O4 ferrites to temperatures of lower than 950°C. Moreover, the V5+ ions occupied the octahedral site of spinel structure and acted as donor dopant, which resulted in the semiconductive grain. The copper-rich observation at the grain boundary based on the TEM and EDS results implied that copper oxide would possibly develop at the grain boundary as the acceptor state, forming double Schottky barriers with the n-type semiconductor grains.

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