scholarly journals Smectitization as a Trigger of Bacterially Mediated Mn-Fe Micronodule Generation in Felsic Glass (Livno-Tomislavgrad Paleolake, Bosnia and Herzegovina)

Minerals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 899
Author(s):  
Luka Badurina ◽  
Branimir Šegvić ◽  
Oleg Mandic ◽  
Giovanni Zanoni
Keyword(s):  
Eastern Europe ◽  
Microbial Activity ◽  
Volcanic Glass ◽  
Initial Step ◽  
X Ray Diffraction ◽  
Pyroclastic Material ◽  
X Ray ◽  
Microbial Life ◽  
Dioctahedral Smectite ◽  
South Eastern Europe

Miocene tuffs preserved in argillaceous sediment interbedded with lacustrine successions are commonly encountered throughout the Dinarides Lake System (DLS) in south-eastern Europe. In this contribution the volcanic glass degradation and co-genetic Mn-Fe precipitation were studied in a 14.68 Ma felsic tuff from DLS Livno-Tomislavgrad Basin. Microbial activity has been involved in both reactions thus adding the interest of revealing effects of biotic and abiotic processes taking place during tuff eogenesis. X-ray diffraction and electron microbeam analysis with energy-dispersive X-ray spectroscopy revealed the pitting or granular structures developed at glass rims along with smectite flakes protruding from a degrading glass. Mn-Fe mineralization emerges in the form of Mn-Fe coatings, an initial step to micronodule formation, where traces of biogenetic influence included a high content of phases rich in structural Mn (IV) (i.e., ranciéite and jacobsite) and presence of microbial microfossils. Co-genetic ties between glass degradation and Mn-Fe precipitation were established through the report of dioctahedral smectite formed out of altered glass; which then served as nuclei of the ongoing biotic and abiotic Mn-Fe mineralization. These processes manifest on a continuous involvement of microbial life in the course of eogenesis of pyroclastic material in lacustrine environments.

scholarly journals Modification of Spent Bleaching Earth with WO3 and the Application for Photocatalytic Degradation of Waste Dyestuff under Solar Light

2020 ◽  
Vol 8 (2) ◽  
pp. 84-89
Author(s):  
Noor Hindryawati ◽  
Aman Sentosa Panggabean ◽  
Dirgarini Julia Nurlianti Subagyono ◽  
Rinda Anisyah Putri ◽  
Prilianda Kusmiaty ◽  
...  
Keyword(s):  
Bleaching Earth ◽  
Catalytic Performance ◽  
Morphological Characterization ◽  
Solar Light ◽  
Blue Dye ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dioctahedral Smectite ◽  
Dioctahedral Mica ◽  
Scanning Electron

Degradation of blue dye waste in Sarong Samarinda production using WO3-bleaching earth (BE) has been conducted. Structural and morphological characterization has conducted using X-ray diffraction (XRD), and Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX). The X-ray diffraction results show the mineral on bleaching earth is rectorite dioctahedral mica layer and dioctahedral smectite with a ratio 2:1. The WO3 pattern is appeared after the calcination. After calcination at 500°C, the WO3 is deposited homogeneously on the BE surface. The catalytic performance of WO3-BE for photodegradation of the blue dye waste under the solar light is 99.85 % within 1 h.

Allophanic and ferric root-associated stalactites: biomineralization induced by microbial activity (Galeria da Queimada lava tube, Terceira, Azores)

2014 ◽  
Vol 152 (3) ◽  
pp. 504-520 ◽  
Author(s):  
R. DAZA ◽  
M. A. BUSTILLO
Keyword(s):  
Manganese Oxide ◽  
Microbial Activity ◽  
Mineralogical Composition ◽  
Filamentous Bacteria ◽  
X Ray Diffraction ◽  
Lava Tube ◽  
Raman Spectrometry ◽  
X Ray ◽  
Oxide Minerals ◽  
Inorganic Precipitation

AbstractRoot-associated stalactites (rootsicles) in Galeria da Queimada lava tube have a mineralogical composition and developmental association with microbes that render them unique. Samples were examined by X-ray diffraction, micro-Raman spectrometry and scanning electron microscopy/X-ray energy-dispersive spectroscopy. Three types of rootsicle were defined: incipient; hard (white and red); and black spongy. The incipient rootsicles still contained rotten organic material and showed the beginning of mineralization by allophane. The white hard and black spongy types were also composed of allophane, while the red hard type was composed of hydrous ferric oxi-hydroxide minerals (HFO). The allophane and HFO in the andisol covering the cave roof precipitated out of the dripwater running along the roots to form the studied rootsicles. All three types of rootsicle showed black layers, coatings, spots or patches composed of manganese oxide minerals and, occasionally, hisingerite (iron (III) phyllosilicate). An alternation of organic precipitation caused by filamentous bacteria and inorganic precipitation (the latter facilitated by pH changes in the dripwater and the cave's temperature) built up both the porous and compact rings observed in the white and red hard rootsicles. The largely straight filaments seen in the porous rings of the white hard rootsicles may be indicative of the previous presence ofLeptothrixspp., while the helical morphologies seen in the red hard rootsicles may be indicative of that ofGallionellaspp. The manganese oxide minerals detected probably formed via microbial activity. This study reflects the important role of filamentous bacteria in rootsicle formation, independent of their mineralogy.

Fabrication and Characterization of Optically Transparent PVDF Films Embedded with Gold Nanoparticles

2021 ◽  
Author(s):  
Caleb Duff ◽  
Alan Rowland ◽  
Alexander Long ◽  
Yanwen Wu
Keyword(s):  
Gold Nanoparticles ◽  
Polyvinylidene Fluoride ◽  
Optoelectronic Devices ◽  
Initial Step ◽  
X Ray Diffraction ◽  
Poling Field ◽  
X Ray ◽  
Piezoelectric Polymer ◽  
Fabrication And Characterization

Abstract Polyvinylidene fluoride is a piezoelectric polymer that can be cast into transparent thin films. New properties can be introduced by embedding nanoparticles in this polymer, making it an excellent platform for flexible and tunable electronic and optoelectronic devices. We develop a recipe for embedding plasmonic gold nanoparticles into these films while maintaining their transparency as an initial step to activate optical response in the film. We characterize films made under different poling conditions with and without nanoparticle inclusions using X-ray diffraction. We find that the inclusion of gold nanoparticles screens the poling field and has a sizable effect on the phase of the produced films.

Mineralogy and geochemical affinities of bentonites from Kapıkaya (Eskişehir, western Turkey)

Clay Minerals ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 339-360 ◽  
Author(s):  
A. Yildiz ◽  
İ. Dumlupunar
Keyword(s):  
Rare Earth ◽  
Clay Minerals ◽  
Volcanic Rocks ◽  
X Ray Diffraction ◽  
Western Turkey ◽  
X Ray ◽  
Geochemical Properties ◽  
Mineral Assemblages ◽  
Parent Rocks ◽  
Dioctahedral Smectite

AbstractThere are numerous bentonite deposits, formed by the alteration of volcanic rocks, in the Kapıkaya area (Eskişehir, western Turkey). These deposits can be classified into three groups according to their stratigraphical levels. X-ray diffraction (XRD), scanning electron microscope (SEM), major, rare-earth and trace-element analyses of bentonites and their parent rocks from the Kapıkaya area were used to evaluate the mineralogical and geochemical properties of bentonites and their parental affinities. Mineral assemblages resulting from bentonite deposits consist mostly of clay minerals, gypsum, cristobalite/opal-CT, quartz, feldspar, calcite and dolomite. The clay minerals are represented mainly by dioctahedral smectite and lesser amounts of illite and chlorite. The enrichment and depletion of the elements indicates open-system alteration conditions. The enrichments in MgO, Fe2O3, TiO2, Co, Pb, Zn, and Ni are related to the precipitation of hydrothermal solutions channelled throughout ultramafic sources. The main differences in mineralogy and geochemistry of bentonites from the Kapıkaya area are in the smectite composition and the contents of major, rare-earth and other trace elements. The data obtained show that the types of parent rock the influenced the mineralogical and geochemical compositions of the bentonites.

The hydrolytic water molecule in trypsin, revealed by time-resolved Laue crystallography

Science ◽  
1993 ◽  
Vol 259 (5095) ◽  
pp. 669-673 ◽  
Author(s):  
PT Singer ◽  
A Smalas ◽  
RP Carty ◽  
WF Mangel ◽  
RM Sweet
Keyword(s):  
Water Molecule ◽  
Three Dimensional ◽  
Initial Step ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Density Maps ◽  
Before And After ◽  
Ph Jump ◽  
Hydrolysis Of

Crystals of bovine trypsin were acylated at the reactive residue, serine 195, to form the transiently stable p-guanidinobenzoate. Hydrolysis of this species was triggered in the crystals by a jump in pH. The hydrolysis was monitored by three-dimensional Laue crystallography, resulting in three x-ray diffraction structures, all from the same crystal and each representing approximately 5 seconds of x-ray exposure. The structures were analyzed at a nominal resolution of 1.8 angstroms and were of sufficient quality to reproduce subtle features in the electron-density maps for each of the structures. Comparison of the structures before and after the pH jump reveals that a water molecule has positioned itself to attack the acyl group in the initial step of the hydrolysis of this transient intermediate.

scholarly journals GEOLOGICAL AND MINERALOGICAL CHARACTERIZATION OF SOME ZEOLITIZED TUFFS FROM NWRN TRANSYLVANIA, ROMANIA

2007 ◽  
Vol 40 (2) ◽  
pp. 666 ◽  
Author(s):  
H. Bedelean ◽  
V. Codrea ◽  
Ο. Barbu
Keyword(s):  
Construction Industry ◽  
Polarized Light ◽  
Volcanic Glass ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Silicic Volcanic ◽  
Wet Chemical ◽  
Representative Samples

Zeolites are the most common products of transformation of silicic volcanic glass in the NW-rn part of Transylvania (Romania). Representative samples of volcanic tuffs from Mäcicas (Cluj county) were investigated by using optical (polarized light) microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and wet chemical analyses. The volcanic tuffare vitreous with an acid composition. Vitreous matrix and glass shards are replaced by zeolite minerals, mainly clinoptilolite and trace amounts ofopal-CT and mordenite. X-ray diffraction semiquantitative analysis indicated that clinoptilolite represent between 60 % and 70 % of the crystalline fraction of the tuff. The clinoptilolite content of the Mäcicas tuff deposits is one of the richest in Romania. According to the present status in the zeolite market in Europe, this deposit could have industrial potential in the construction industry and in environmental applications.

scholarly journals Prograde and retrograde diagenetic and metamorphic evolution in metapelitic rocks of Sierra Espuña (Spain)

Clay Minerals ◽  
2003 ◽  
Vol 38 (1) ◽  
pp. 1-23 ◽  
Author(s):  
I . Abad ◽  
F. Nieto ◽  
D. R. Peacor ◽  
N. Velilla
Keyword(s):  
Electron Microscopy ◽  
Tectonic Stress ◽  
Complete Sequence ◽  
Reaction Series ◽  
X Ray Diffraction ◽  
Metamorphic Evolution ◽  
X Ray ◽  
Dioctahedral Smectite ◽  
Intermediate Units ◽  
Pelitic Rocks

AbstractAn unusually complete sequence of pelitic rocks ranging from diagenetic to greenschist-facies metamorphic grades occurs in southern Sierra Espun˜a, Spain. Prograde and retrograde reactions have been studied by X-ray diffraction and electron microscopy (SEM, TEM and AEM). The prograde reaction series, with reactions facilitated by tectonic stress, includes: (1) R4 interstratified illite-smectite in the diagenetic Malaguide Complex that preserves the variable orientation of original smectite packets, and has 1Md polytypism; (2) chemically heterogeneous illite and Na-K dioctahedral white micas that progressively evolve toward chemical and textural equilibrium in the anchizonal Intermediate Units; and (3) thick, defect-free packets of phengite, paragonite and clinochlore which have a typical metamorphic texture, in the Alpujarride Complex. Two superimposed retrograde episodes produced: (a) sudoite at near-peak metamorphic conditions and (b) dioctahedral smectite during low-temperature retrograde diagenesis.

Origin of the Basoren (Kutahya, W Turkey) bentonite deposits

Clay Minerals ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 219-231 ◽  
Author(s):  
A. Yildiz ◽  
M. Kuscu
Keyword(s):  
Chemical Composition ◽  
Hydrothermal Alteration ◽  
Volcanic Glass ◽  
Hydrothermal Solutions ◽  
X Ray Diffraction ◽  
Pyroclastic Rocks ◽  
X Ray ◽  
Alteration Zones ◽  
Parent Rocks ◽  
Ophiolitic Rocks

AbstractBentonite deposits in Basoren Kutahya, West Anatolia, Turkey formed from alteration of perlite and pyroclastic rocks of Pliocene age. The distribution of bentonite deposits along faults in the study area indicates that the alteration solutions were hydrothermal. Although lateral zonation is observed in bentonite deposits in some regions (i.e. Demirli, Akyokus, Seklice- Sarıokuz, etc.), alteration zones are extremely irregular in the Cayırlık bentonite deposit.X-ray diffraction studies have shown that Basoren bentonites contain dioctahedral Ca-smectite.The Greene-Kelly test (Li-saturation and heating) showed that the Demirli and Akyokus bentonites consist of montmorillonite and that the Cayırlık bentonite consists of montmorillonite and/or beidellite. Spherulitic or hemispherical ‘crystals’ of opal-CT minerals formed from hydrothermal alteration of volcanic glass. The MgO, CaO and total Fe2O3 enrichment in bentonites, compared to parent rocks, is related to the chemical composition of hydrothermal solutions that passed through the ophiolitic rocks such as serpentinite.

scholarly journals Investigation of dioctahedral smectite hydration properties by modeling of X-ray diffraction profiles: Influence of layer charge and charge location

2007 ◽  
Vol 92 (10) ◽  
pp. 1731-1743 ◽  
Author(s):  
E. Ferrage ◽  
B. Lanson ◽  
B. A. Sakharov ◽  
N. Geoffroy ◽  
E. Jacquot ◽  
...  
Keyword(s):  
Layer Charge ◽  
X Ray Diffraction ◽  
Hydration Properties ◽  
X Ray ◽  
Dioctahedral Smectite
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