scholarly journals Polyphase white mica growth in low-grade metapelites from La Cebila Metamorphic Complex (Famatinian Belt, Argentina): evidence from microstructural and XRD investigations.

2011 ◽  
Vol 38 (2) ◽  
pp. 268 ◽  
Author(s):  
Sebastian O. Verdecchia ◽  
Gilda Collo ◽  
Edgardo G. Baldo
Keyword(s):  
White Mica ◽  
Low Grade ◽  
Metamorphic Complex ◽  
Mineral Analysis ◽  
Chemical Parameter ◽  
Sierras Pampeanas ◽  
Kübler Index ◽  
Event Based ◽  
Parameter Values

Two tectono-thermal metamorphic events, M1-D1 (S1, with associated white mica and chlorite: WM1-Chl1) and M2-D2 (S2, with development of WM2-Chl2), are established from polyphase white mica growth for low-grade units from the Ordovician metasedimentary successions of La Cebila Metamorphic Complex in the Famatinian belt (western-central Argentina). The thermobarometric characterization of the M1 main event was carried out by means of clay-mineral analysis and crystallo-chemical parameter measurements. Epizonal (temperatures between 300 and 400ºC) and low-pressure conditions are suggested for M1 event, based in Kübler index values ranging from 0.23 to 0.17 Δº2θ, white mica b parameter values between 9.004 and 9.022 Å (mean of 9.014 Å, n=16) and Si contents between 3.13-3.29 a.p.f.u. Temperatures of ~180-270ºC are estimated for the M2 event, with Kübler index values ranging from 0.31 to 0.46 Δº2θ. The M1-D1 event of La Cebila could be linked to highstrain heating tectono-metamorphic Ordovician regime recorded in others complexes from Famatinian foreland region of Sierras Pampeanas.

scholarly journals The thrust contact between the Canastra and Vazante groups in the Southern Brasília Belt: structural evolution, white mica crystallinity and implications for the Brasiliano orogeny

2016 ◽  
Vol 46 (4) ◽  
pp. 567-583 ◽  
Author(s):  
Manuela de Oliveira Carvalho ◽  
◽  
Claudio de Morisson Valeriano ◽  
Pamela Alejandra Aparicio González ◽  
Gustavo Diniz Oliveira ◽  
...  
Keyword(s):  
Structural Evolution ◽  
White Mica ◽  
Low Grade ◽  
Kink Bands ◽  
Metasedimentary Rocks ◽  
Kübler Index ◽  
Crenulation Cleavage ◽  
Thrust Sheets ◽  
Brasiliano Orogeny ◽  
Carbonaceous Phyllite

ABSTRACT: Two regional thrust-sheets of Neoproterozoic metasedimentary rocks occur in the Southern Brasília Belt, northwest Minas Gerais. The lower one comprises the Vazante Group, that is formed in the studied area, from base to top, by the Serra do Garrote (metapelites interlayered with carbonaceous phyllite), Serra do Poço Verde (beige to pink stromatolitic metadolomite with interlayered greenish slates), Morro do Calcário (gray stromatolitic metadolomite interlayered with gray slates) and Serra da Lapa (phyllite with dolarenitic lenses interlayered with slates) formations. The upper thrust sheet consists of the Canastra Group (Paracatu formation): laminated sericite phyllites and carbonaceous phyllites interlayered with quartzite. The Braziliano orogeny resulted in four phases of contractional deformation, associated with low-grade metamorphism. The first two (D1 and D2) are ductile, while the third and fourth ones (D3 and D4) are brittle-ductile. D1 developed a slaty S1 cleavage subparallel to the primary layering, with shallow to steep dips to NW. D2 developed a crenulation cleavage (S2) that dips moderately to NW and is associated with tight to isoclinal folds. D3 and D4 phases developed crenulations and open folds and kink bands. S3 dips steeply to NW, while S4 has moderate to steep dips to NE and SW. White mica crystallinity (Kübler index) measurements in metapelites indicate that both the Canastra and Vazante groups reached anchizone/epizone conditions, and metamorphic discontinuities along thrusts indicate that the peak of metamorphism is pre or syn-thrusting.

Diagenesis to metamorphism transition in an episutural basin: the late Paleozoic St. Mary’s Basin, Nova Scotia, Canada

2010 ◽  
Vol 47 (2) ◽  
pp. 121-135 ◽  
Author(s):  
Isabel Abad ◽  
J. Brendan Murphy ◽  
Fernando Nieto ◽  
Gabriel Gutiérrez-Alonso
Keyword(s):  
Fluid Flow ◽  
Sedimentary Basins ◽  
Early Carboniferous ◽  
White Mica ◽  
Low Grade ◽  
Northern Margin ◽  
Clastic Rocks ◽  
Kübler Index ◽  
Dextral Shear ◽  
Mixed Layers

The Late Devonian – Early Carboniferous St. Mary’s Basin in the Canadian Appalachians consists of Horton Group fluviatile and lacustrine clastic rocks. The basin occurs along the boundary between the Avalon and Meguma terranes and developed during coeval dextral shear along that boundary. X-ray diffraction reveals that the rocks contain ubiquitous quartz, K-white mica, and albite; illite–smectite mixed layers and chlorite are very common and Na–K mica, kaolinite, chlorite–smectite mixed layers, K-feldspar, berthierine, and rutile occur in some samples. Crystal-chemical parameters of white mica indicate the pressure and temperature of mineral growth and discriminate between diagenetic, anchizone, and low-grade metamorphic processes. Kübler index values measured in the 5 Å peak and the presence of chlorite–mica stacks are indicative of high-anchizone–epizone grades, with a crystallinity (crystal size and number of defects) that increases towards the Chedabucto Fault, which defines the northern margin of the basin. Kübler index values measured in the 10 Å peak indicate that a late fluid-rich event could have produced the observed illite–smectite mixed layers. The overall clay-mineral content and the b-cell dimension of the K-white micas are typical of postdepositional evolution in extensional sedimentary basins with high heat flow (>35 °C/km). Taken together, our data record two superposed events related to deformation along the basin margins and coeval regional fluid flow, in which retrograde reactions at temperature T < 200 °C were superimposed on a pre-existing prograde assemblage typical of high-anchizone – lower greenschist-facies conditions (T > 300 °C). Regional syntheses indicate that this fluid flow may have occurred during episodes of Late Carboniferous dextral shear along the Avalon–Meguma terrane boundary.

Comparison of Immunological and Functional Assays for Measurement of Soluble Fibrin

1995 ◽  
Vol 74 (02) ◽  
pp. 673-679 ◽  
Author(s):  
C E Dempfle ◽  
S A Pfitzner ◽  
M Dollman ◽  
K Huck ◽  
G Stehle ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Low Grade ◽  
Plasma Samples ◽  
Normal Range ◽  
Soluble Fibrin ◽  
Discriminating Power ◽  
Fibrin Monomer ◽  
Cerebral Ischemic

SummaryVarious assays have been developed for quantitation of soluble fibrin or fibrin monomer in clinical plasma samples, since this parameter directly reflects in vivo thrombin action on fibrinogen. Using plasma samples from healthy blood donors, patients with cerebral ischemic insult, patients with septicemia, and patients with venous thrombosis, we compared two immunologic tests using monoclonal antibodies against fibrin-specific neo-epitopes, and two functional tests based on the cofactor activity of soluble fibrin complexes in tPA-induced plasminogen activation. Test A (Enzymun®-Test FM) showed the best discriminating power among normal range and pathological samples. Test B (Fibrinostika® soluble fibrin) clearly separated normal range from pathological samples, but failed to discriminate among samples from patients with low grade coagulation activation in septicemia, and massive activation in venous thrombosis. Functional test C (Fibrin monomer test Behring) displayed good discriminating power between normal and pathological range samples, and correlated with test A (r = 0.61), whereas assay D (Coa-Set® Fibrin monomer) showed little discriminating power at values below 10 μg/ml and little correlation with other assays. Standardization of assays will require further characterization of analytes detected.

scholarly journals The low-grade basement at Península La Carmela, Chilean Patagonia: new data for unraveling the pre-Permian basin nature of the Eastern Andean Metamorphic Complex

2021 ◽  
Author(s):  
D. Rojo ◽  
M. Calderón ◽  
M. C. Ghiglione ◽  
R. J. Suárez ◽  
P. Quezada ◽  
...  
Keyword(s):  
Low Grade ◽  
Metamorphic Complex ◽  
Permian Basin ◽  
Chilean Patagonia

scholarly journals Synthesis of a New Phosphonate-Based Sorbent and Characterization of Its Interactions with Lanthanum (III) and Terbium (III)

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1513
Author(s):  
Yuezhou Wei ◽  
Khalid A. M. Salih ◽  
Mohammed F. Hamza ◽  
Toyohisa Fujita ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
High Tech ◽  
Low Grade ◽  
Acid Solutions ◽  
Hydrogel Beads ◽  
Secondary Sources ◽  
Composite Sorbents ◽  
Synthesis Procedure ◽  
New Generation ◽  
Mild Acid

High-tech applications require increasing amounts of rare earth elements (REE). Their recovery from low-grade minerals and their recycling from secondary sources (as waste materials) are of critical importance. There is increasing attention paid to the development of new sorbents for REE recovery from dilute solutions. A new generation of composite sorbents based on brown algal biomass (alginate) and polyethylenimine (PEI) was recently developed (ALPEI hydrogel beads). The phosphorylation of the beads strongly improves the affinity of the sorbents for REEs (such as La and Tb): by 4.5 to 6.9 times compared with raw beads. The synthesis procedure (epicholorhydrin-activation, phosphorylation and de-esterification) is investigated by XPS and FTIR for characterizing the grafting route but also for interpreting the binding mechanism (contribution of N-bearing from PEI, O-bearing from alginate and P-bearing groups). Metal ions can be readily eluted using an acidic calcium chloride solution, which regenerates the sorbent: the FTIR spectra are hardly changed after five successive cycles of sorption and desorption. The materials are also characterized by elemental, textural and thermogravimetric analyses. The phosphorylation of ALPEI beads by this new method opens promising perspectives for the recovery of these strategic metals from mild acid solutions (i.e., pH ~ 4).

Study of Low-Grade Nickel Laterite Processing Using Palm Shell Charcoal as Reductant

2020 ◽  
Vol 1000 ◽  
pp. 436-446
Author(s):  
Bambang Suharno ◽  
Nolzha Primadha Ilman ◽  
Achmad Shofi ◽  
Deni Ferdian ◽  
Fajar Nurjaman
Keyword(s):  
Sodium Sulfate ◽  
Selective Reduction ◽  
Reduction Process ◽  
Low Grade ◽  
X Ray Diffraction ◽  
X Ray ◽  
Palm Shell ◽  
Higher Temperature ◽  
Nickel Grade

This study was conducted to investigate the effect of palm shell charcoal reductant in the selective reduction of nickel ore with the addition of additive at various temperatures and times. In this present work, 10 wt. % of sodium sulfate as additive and 5, 10, 15 wt. % of palm shell charcoal as reductants were used. The reduction of nickel ore was performed at 950oC, 1050oC, and 1150oC for 60, 90, and 120 minutes. A wet magnetic separation method was then carried out to separate the concentrates and tailings. Characterization of reduced ore was performed by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM) with Energy Dispersive X-ray Spectroscopy (EDS), while the composition of ferronickel in concentrate was identified by X-Ray Fluorescence (XRF). The result showed that the higher temperature reduction, the higher of nickel grade, and its recovery at the concentrate. Nevertheless, the longer reduction time and the more reductant in nickel ore lowering the nickel grade and its recovery in the concentrate. The optimum condition in this selective reduction process was obtained with the addition of 5 wt. % of reductant and 10 wt. % of sodium sulfate in nickel ore, which was reduced at 1150oC for 60 minutes. It resulted in 4.60% and 73.23% for nickel grade and its recovery, respectively.

Structural characterization of two K2SnX(PO4)3 (X=Fe,Yb) with langbeinite structure

2006 ◽  
Vol 21 (3) ◽  
pp. 214-219 ◽  
Author(s):  
Abderrahim Aatiq ◽  
Btissame Haggouch ◽  
Rachid Bakri ◽  
Youssef Lakhdar ◽  
Ismael Saadoune
Keyword(s):  
Solid State ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Cell Parameter ◽  
Rietveld Analysis ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Octahedral Sites ◽  
Parameter Values

Structures of two K2SnX(PO4)3(X=Fe,Yb) phosphates, obtained by conventional solid state reaction techniques at 950 °C, were determined at room temperature by X-ray powder diffraction using Rietveld analysis. The two materials exhibit the langbeinite-type structure (P213 space group, Z=4). Cubic unit cell parameter values are: a=9.9217(4) Å and a=10.1583(4) Å for K2SnFe(PO4)3 and K2SnYb(PO4)3, respectively. Structural refinements show that the two crystallographically independent octahedral sites (of symmetry 3) have a mixed Sn∕X (X=Fe,Yb) population although ordering is stronger in the Yb phase than in the Fe phase.

scholarly journals Analysis of EGFR and HER-2 expressions in ductal carcinomas in situ in canine mammary glands

2014 ◽  
Vol 66 (3) ◽  
pp. 763-768 ◽  
Author(s):  
I.L.D. Silva ◽  
A.P.M. Dias ◽  
A.C. Bertagnolli ◽  
G.D. Cassali ◽  
E. Ferreira
Keyword(s):  
Ductal Carcinoma ◽  
Mammary Glands ◽  
Statistical Correlation ◽  
Low Grade ◽  
Neoplastic Progression ◽  
Her 2 ◽  
Epidermal Growth ◽  
Ductal Carcinomas

Biomolecular evidence has shown that ductal carcinoma in situ(DCIS) may develop into invasive carcinoma of the canine mammary gland, and mutations in proto-oncogenes HER2 and EGFR; two members of the family of epidermal growth factor receptors, may be involved in this process. The purpose of this study was the characterization of the immunohistochemical expression of the EGFR and HER2 proteins in the process of neoplastic transformation, supposedly present in ductal carcinomas in situin canine mammary glands. Fifteen cases of DCIS were evaluated, with a higher expression of HER2 and EGFR being observed in low-grade carcinomas when compared with high-grade neoplasms, and with a high positive statistical correlation in the latter. Results suggest that aggressive tumors tend to lose the expression of EGFR and HER2 simultaneously. The loss of the expression of these markers may be related to the process of neoplastic progression in canine mammary tumors.

scholarly journals OGLE-2009-BLG-023/MOA-2009-BLG-028: characterization of a binary microlensing event based on survey data

2011 ◽  
Vol 413 (2) ◽  
pp. 1244-1250
Author(s):  
K.-H. Hwang ◽  
C. Han ◽  
A. Udalski ◽  
T. Sumi ◽  
A. Gould ◽  
...  
Keyword(s):  
Survey Data ◽  
Event Based
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