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X-ray science: The big guns

X-ray science: The big guns | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Powerful X-ray lasers are getting to the heart of matter.
Ath Godelitsas's insight:

X-ray free-electron lasers (XFELs), is a tool for studying challenging forms of matter.

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High-Energy Surface X-Ray Diffraction for Fast Surface Structure Determination

High-Energy Surface X-Ray Diffraction for Fast Surface Structure Determination | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

By using a novel X-ray technique, researchers have observed a catalyst surface at work in real time and were able to resolve its atomic structure in detail. The new technique, pioneered at DESY's X-ray light source PETRA III, may pave the way for the design of better catalysts and other materials on the atomic level. It greatly speeds up the determination of atomic surface structures and enables live recordings of surface reactions like catalysis, corrosion and growth processes with a time resolution of less than a second.

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Detection of solar wind-produced water in irradiated rims on silicate minerals

Detection of solar wind-produced water in irradiated rims on silicate minerals | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

By exploiting the high spatial resolution of TEM and EELS the authors detected water sealed in vesicles within amorphous rims produced by Solar Wind (SW) irradiation of silicate mineral grains on the exterior surfaces of interplanetary dust particles. Their findings establish that water is a byproduct of SW space weathering.

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Silver nanoparticle concentrations within a porous medium via Synchrotron X-ray Computed Microtomography

Silver nanoparticle concentrations within a porous medium via Synchrotron X-ray Computed Microtomography | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

This paper is the first to present a method for high resolution quantification of silver nanoparticle (nAg) concentrations within porous media under controlled experimental conditions. This method makes it possible to extract silver nanoparticle concentrations within individual pores in static and quasi-dynamic (i.e., transport) systems. Quantification is achieved by employing absorption-edge synchrotron X-ray computed microtomography (SXCMT) and an extension of the Beer–Lambert law.

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ZEOLITE 2014

ZEOLITE 2014 | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The 9th International Conference on the Occurrence, Properties, and Utilization of Natural Zeolites - Zeolite 2014 will be held from the 8th to 13th of June 2014 in Belgrade, Serbia. On behalf of the Organizing Committee of Zeolite 2014, we have the pleasure to cordially invite all researchers and interested parties to join us in participating in the scientific conference and related events.

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Mineralogy of a Mudstone at Yellowknife Bay, Gale Crater, Mars

Mineralogy of a Mudstone at Yellowknife Bay, Gale Crater, Mars | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

See also: http://authors.library.caltech.edu/42649/

Ath Godelitsas's insight:

Sedimentary rocks at Yellowknife Bay (Gale crater) on Mars include mudstone sampled by the Curiosity rover. The samples, John Klein and Cumberland, contain detrital basaltic minerals, calcium sulfates, iron oxide or hydroxides, iron sulfides, amorphous material, and trioctahedral smectites.

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National contributions to observed global warming

National contributions to observed global warming | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

There is considerable interest in identifying national contributions to global warming as a way of allocating historical responsibility for observed climate change

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Aluminum Affects Heterogeneous Fe(III) (Hydr)oxide Nucleation, Growth, and Ostwald Ripening

Aluminum Affects Heterogeneous Fe(III) (Hydr)oxide Nucleation, Growth, and Ostwald Ripening | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors, using a Synchrotron-based small-angle X-ray scattering technique, they studied heterogeneous nucleation and growth of Fe(III) (hydr)oxide on quartz under conditions found in acid mine drainage (at pH = 3.7 ± 0.2, [Fe3+] = 10–4 M) with different initial aqueous Al/Fe ratios (0:1, 1:1, and 5:1).

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Influence of Radioactivity on Surface Charging and Aggregation Kinetics of Particles in the Atmosphere

Influence of Radioactivity on Surface Charging and Aggregation Kinetics of Particles in the Atmosphere | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Experimental and theoretical studies have been performed to investigate the influence of radioactivity on surface charging and aggregation kinetics of radioactive particles in the atmosphere.

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Design of Nanosensors for Fissile Materials in Nuclear Waste Water

Design of Nanosensors for Fissile Materials in Nuclear Waste Water | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors performed ab initio density functional theory calculations of U and Pu complexes with graphene and graphene oxide to examine the applicability of a graphene-based fissile sensor. They found that graphene needs to be functionalized to act as an effective sensor for detection of fissile materials such as uranium and plutonium complexes.

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Oriented Calcite Micropillars and Prisms Formed through Aggregation and Recrystallization of Poly(Acrylic Acid) Stabilized Nanoparticles

Oriented Calcite Micropillars and Prisms Formed through Aggregation and Recrystallization of Poly(Acrylic Acid) Stabilized Nanoparticles | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The authors show that by combining the effects of poly(acrylic acid) (PAA) and calcite substrates we can direct the formation of calcite through an intermediate complex of PAA and Ca2+ into oriented calcite micropillars with {104} faceted coaligned platelike subunits.

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The stability of Fe–Ni carbides in the Earthʼs mantle

The stability of Fe–Ni carbides in the Earthʼs mantle | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

Possible Fe–Ni–C phase associations at ∼400 km depth in the adiabatic deep mantle (1475 °C) and in metasomatized mantle domains.

Ath Godelitsas's insight:

The Earthʼs mantle contains significant amounts of carbon and is at depths greater than ∼250–300 km potentially so reducing that the Fe–C redox couple determines the nature of the reduced phase(s), which may be diamond, metal and carbides. Carbides will be Fe-rich but their stability also depends on the presence of Ni. We thus have experimentally investigated the Fe–Ni–C subsolidus ternary at 10 GPa, and secondly determined eutectic melting temperatures in this system.

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When Earth's Crust Was Drippy

Ath Godelitsas's insight:

Today, Earth’s crust is made of tectonic plates that jostle across its surface and are sometimes, via collisions, gradually shoved back into the depths. But long before this mode of geological recycling arose, large blobs of dense material solidified on the undersides of Earth’s nascent tectonic plates and then dripped back toward our planet’s core, a new study suggests.

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Thermal equation of state and spin transition of magnesiosiderite at high pressure and temperature

Thermal equation of state and spin transition of magnesiosiderite at high pressure and temperature | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The research team, with funding from the Deep Carbon Observatory, used an intense Synchrotron X-ray diffraction beamline at the Advanced Photon Source to deduce the spin states of iron from X-ray diffraction patterns of a tiny ferromagnesite sample in a high pressure-temperature diamond anvil cell. Their results show that the spin transition of iron in ferromagnesite is strongly associated with a unit cell volume collapse from the high-spin to the low-spin state, resulting in significant changes in physical and potentially chemical properties of carbonate.

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From nanometer aggregates to micrometer crystals: Insight into the coarsening mechanism of calcite

From nanometer aggregates to micrometer crystals: Insight into the coarsening mechanism of calcite | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Scanning electron microscopy (SEM) and BET surface area analysis showed rapid coarsening at 100 and 200 °C. Evidence of particle growth at 23 °C was not visible by SEM but high resolution X-ray diffraction (XRD) data demonstrated steady growth of nanometer crystallites. The results can be described by theory where grains coarsen preferentially by aggregation at early times and high temperatures and by Ostwald ripening at later stages.

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Nanoparticles Meet Cell Membranes

Nanoparticles Meet Cell Membranes | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The propensities for nanoparticles to attach to and disrupt cell membranes are still not well understood due to the heterogeneous and dynamic nature of biological membranes. Model biological membranes can be employed for systematic investigations of nanoparticle−membrane interactions.

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Elemental Geochemistry of Sedimentary Rocks at Yellowknife Bay, Gale Crater, Mars

Elemental Geochemistry of Sedimentary Rocks at Yellowknife Bay, Gale Crater, Mars | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

See also: http://authors.library.caltech.edu/42646/

Ath Godelitsas's insight:

Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition.

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Exploring Martian Habitability

Exploring Martian Habitability | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Five articles presented in the 24 January edition of Science describe the detection at Gale crater of a system of ancient environments that would have been habitable by chemoautotrophic microorganisms. A sixth article details a more ancient and also potentially habitable environment detected in Noachian age (>~3.7 billion years) rocks at Meridiani Planum. A seventh article describes the present radiation environment on the surface of Mars at Gale crater.

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Monitoring of Stainless-Steel Slag Carbonation Using X-ray Computed Microtomography

Monitoring of Stainless-Steel Slag Carbonation Using X-ray Computed Microtomography | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Steel production is one of the largest contributors to industrial CO2 emissions. This industry also generates large amounts of solid byproducts, such as slag and sludge. High-resolution X-ray computed tomography (HRXCT) is applied to visualize and quantify the changes in situ during the carbonation process.

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Arsenic Species Formed from Arsenopyrite Weathering along a Contamination Gradient in Circumneutral River Floodplain Soils

Arsenic Species Formed from Arsenopyrite Weathering along a Contamination Gradient in Circumneutral River Floodplain Soils | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Soil samples collected in the floodplain of Ogosta River (Bulgaria) were size-fractionated and subsequently analyzed using a combination of X-ray fluorescence (XRF) spectrometry, powder X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and selective chemical extraction of poorly crystalline mineral phases. Arsenic and Fe were found to be spatially correlated and both elements were strongly enriched in the fine soil particle size fractions (<2 μm and 2–50 μm).

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Spatial Arrangement of Organic Compounds on a Model Mineral Surface: Implications for Soil Organic Matter Stabilization

Spatial Arrangement of Organic Compounds on a Model Mineral Surface: Implications for Soil Organic Matter Stabilization | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

The complexity of the mineral–organic carbon interface may influence the extent of stabilization of organic carbon compounds in soils, which is important for global climate futures. The nanoscale structure of a model interface was examined here by depositing films of organic carbon compounds of contrasting chemical character, hydrophilic glucose and amphiphilic stearic acid, onto a soil mineral analogue (Al2O3).

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Goldschmidt2014 (Session 22a): Environmental and Nanominerals

Goldschmidt2014 (Session 22a): Environmental and Nanominerals | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

This session focuses on nanominerals and mineral nanoparticles, particularly the ways in which their properties deviate from those of bulk minerals. Additional themes include the ways in which nanoparticles contribute to environmental pollution and how they might help in remediation of existing pollution or prevent future problems. Presentations will address the nature, reactivity, and quantity of nanoparticles in soils, sediments, waste forms, sub-surface, rivers, oceans and air, and how we characterize their properties. Of specific interest is the transport of contaminants within or on the surfaces of nanoparticles and the reactivity of nanoparticulate materials toward contaminants. We seek a balanced combination of field, laboratory, and computational studies which will present the recent advances and the future challenges in this field.

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Nanomagnetic intergrowths in Fe–Ni meteoritic metal: The potential for time-resolved records of planetesimal dynamo fields

Nanomagnetic intergrowths in Fe–Ni meteoritic metal: The potential for time-resolved records of planetesimal dynamo fields | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it
Ath Godelitsas's insight:

Nanoscale intergrowths unique to the cloudy zones (CZs) of meteoritic metal display novel magnetic behaviour with the potential to reveal new insight into the early development of magnetic fields on protoplanetary bodies. The nanomagnetic state of the CZ within the Tazewell IIICD iron meteorite has been imaged using off-axis electron holography. The CZ is revealed to be a natural nanocomposite of magnetically hard islands of tetrataenite (ordered FeNi) embedded in a magnetically soft matrix of ordered Fe3Ni.

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Supervolcano triggers recreated in Synchrotron

Supervolcano triggers recreated in Synchrotron | Mineralogy, Geochemistry, Mineral Surfaces & Nanogeoscience | Scoop.it

The X-ray beam penetrates the sample inside the press and its interaction with the magma rock is recorded in an X-ray detector behind the press. The insert shows a typical absorbance map recorded by the detector from which the density of the sample is derived. Credit ESRF/Nigel Hawtin; see also: http://www.esrf.eu/home/news/general/content-news/general/supervolcano-triggers-recreated-in-x-ray-laboratory.html

Ath Godelitsas's insight:

The authors have used Synchrotron measurements of X-ray absorption to determine the density of silica-rich magmas at pressures and temperatures of up to 3.6 GPa and 1,950 K, respectively.

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