A5008001134- Radioactive element chemistry and processing
- Geochemistry and Elemental Analysis
- Bone Tissue Engineering Materials
- Atmospheric and Environmental Gas Dynamics
- Ferroelectric and Negative Capacitance Devices
- Semiconductor materials and devices
- Semiconductor materials and interfaces
- Radioactive contamination and transfer
- Calcium Carbonate Crystallization and Inhibition
- Hydrocarbon exploration and reservoir analysis
- Geochemistry and Geologic Mapping
- X-ray Diffraction in Crystallography
- Intermetallics and Advanced Alloy Properties
- Electronic and Structural Properties of Oxides
- Nanoparticles: synthesis and applications
- Catalysis and Oxidation Reactions
- Catalytic Processes in Materials Science
- Physics of Superconductivity and Magnetism
- Chalcogenide Semiconductor Thin Films
- Ion-surface interactions and analysis
- Radioactivity and Radon Measurements
- Crystallization and Solubility Studies
- Nonlinear Optical Materials Research
- Liquid Crystal Research Advancements
- Geological Studies and Exploration
Russian Academy of Sciences
2014-2024
École Polytechnique Fédérale de Lausanne
2009-2024
A.V. Shubnikov Institute of Crystallography
2013-2023
Federal Scientific Research Centre Crystallography and Photonics
2017-2023
Saint Petersburg State University of Aerospace and Instrumentation
2017-2018
Moscow Institute of Physics and Technology
2016-2017
École Polytechnique
2013
Stanford Synchrotron Radiation Lightsource
2008-2010
Pacific Northwest National Laboratory
2008-2009
Los Alamos National Laboratory
2008
Because of their immense scalability and manufacturability potential, the HfO2-based ferroelectric films attract significant attention as strong candidates for application in memories related electronic devices. Here, we report behavior ultrathin Hf0.5Zr0.5O2 films, with thickness just 2.5 nm, which makes them suitable use tunnel junctions, thereby further expanding area practical application. Transmission electron microscopy diffraction analysis grown on highly doped Si substrates confirms...
A promising remediation approach to mitigate subsurface uranium contamination is the stimulation of indigenous bacteria reduce mobile U(VI) sparingly soluble U(IV). The product microbial reduction often reported as mineral uraninite. Here, we show that end products by several environmentally relevant (Gram-positive and Gram-negative) their spores include a variety U(IV) species other than were prepared in chemically variable media characterized using transmission electron microscopy (TEM)...
This work investigates the potential for harnessing association of bacterial proteins to biogenic selenium nanoparticles (SeNPs) control size distribution and morphology resultant SeNPs. We conducted a proteomic study compared associated with SeNPs produced by E. coli chemically synthesized as well magnetite nanoparticles. identified four (AdhP, Idh, OmpC, AceA) that bound specifically observed narrower more spherical when particles were in presence proteins. A detailed AdhP (alcohol...
The reduction of soluble hexavalent uranium to tetravalent can be catalyzed by bacteria and minerals. end-product this is often the mineral uraninite, which was long assumed only product U(VI) reduction. However, recent studies report formation other species including an adsorbed U(IV) species, operationally referred as monomeric U(IV). discovery important because likely more labile susceptible reoxidation than uraninite. Because there a need distinguish between these two we propose here wet...
The stability of biogenic uraninite with respect to oxidation is seminal the success in situ bioreduction strategies for remediation subsurface U(VI) contamination. properties and hence are dependent on its size, structure, composition. In this study, local-, intermediate-, long-range molecular-scale structure nanoscale produced by Shewanella oneidensis strain MR-1 was investigated using EXAFS, SR-based powder diffraction TEM. products were found be structurally homologous stoichiometric UO2...
Since the discovery of ferroelectricity (FE) in HfO2-based thin films, they are gaining increasing attention as a viable alternative to conventional FE next generation non-volatile memory devices. In order further increase density elements integrated circuits, it is essential adopt three-dimensional design. atomic layer deposition (ALD) processes extremely conformal, ALD favored approach production 3D ferroelectric random access memory. Here, we report fabrication fully ALD-grown capacitors...
Reductive bioremediation is currently being explored as a possible strategy for uranium-contaminated aquifers such the Old Rifle site (Colorado). The stability of U(IV) phases under oxidizing conditions key to performance this procedure. An in situ method was developed study oxidative dissolution biogenic uraninite (UO₂), desirable U(VI) bioreduction product, Rifle, CO, aquifer different variable oxygen conditions. Overall uranium loss rates were 50-100 times slower than laboratory rates....
In this study, we report the results of in situ U(VI) bioreduction experiments at Integrated Field Research Challenge site Rifle, Colorado, USA. Columns filled with sediments were deployed into a groundwater well and, after period conditioning groundwater, amended mixture soluble U(VI), and acetate to stimulate growth indigenous microorganisms. Individual reactors collected as various redox regimes column achieved: (i) during iron reduction, (ii) just onset sulfate (iii) later reduction. The...
Arsenic contamination in groundwater is pervasive throughout deltaic regions of Southeast Asia and threatens the health millions. The speciation As sediments overlying contaminated aquifers poorly constrained. Here, we investigate chemical mineralogical compositions sediment cores collected from Mekong Delta Vietnam, elucidate iron arsenic, relate them to depositional environment. Gradual dissolution ferric (oxyhydr)oxides with depth observed down 7 m, corresponding establishment reducing...
Because of their compatibility with modern Si-based technology, HfO2-based ferroelectric films have recently attracted attention as strong candidates for applications in memory devices, particular, field-effect transistors or tunnel junctions. A key property defining the functionality these devices is polarization dependent change electronic band alignment at metal/ferroelectric interface. Here, we report on effect reversal functional TiN/Hf0.5Zr0.5O2/TiN capacitors potential distribution...
Wetlands often act as sinks for uranium and other trace elements. Our previous work at a mining-impacted wetland in France showed that labile noncrystalline U(IV) species consisting of bound to Al-P-Fe-Si aggregates was predominant the soil locations exhibiting U-containing clay-rich layer within top 30 cm. Additionally, porewater, association with Fe(II) organic matter colloids significantly increased mobility wetland. In present study, same wetland, we further demonstrate speciation U...
While the product of microbial uranium reduction is often reported to be "UO(2)", a comprehensive characterization including stoichiometry and unit cell determination available for only one Shewanella species. Here, we compare products batch uranyl by collection dissimilatory metal- sulfate-reducing bacteria genera Shewanella, Geobacter, Anaeromyxobacter, Desulfovibrio under similar laboratory conditions. Our results demonstrate that U(VI) bioreduction this assortment commonly studied,...
Chromate is a highly toxic oxyanion. Extensive industrial use and inadequate waste management has caused the pollution of several field sites. Understanding chromate resistance mechanisms that enable organisms to thrive under these conditions fundamental develop (micro)biological strategies applications aiming at bioremediation contaminated soils or waters. Potential detoxifying microorganisms are often not sufficient in their characteristics effectively perform, e.g., reduction biosorption....
This study presents field experiments conducted in a contaminated aquifer Rifle, CO, to determine the speciation and accumulation of uranium sediments during situ bioreduction. We applied synchrotron-based X-ray spectroscopy imaging techniques as well aqueous chemistry measurements identify changes U water sediment first days follwing electron donor amendment. Limited solid were observed throughout duration this study, non-crystalline U(IV) was identified all samples obtained. However, rates...
A comparative characterization of the structure normal and abnormal (osteoporotic) human lumbar thoracic vertebrae samples was carried out to reveal type possible disorder. Samples from bone fragments extracted during surgery due vertebra fractures were examined by scanning electron microscopy (SEM), conventional high resolution transmission (TEM HRTEM), X-ray energy dispersive spectroscopy (EDS). Contrary what might be expected in accordance with processes dissolution, formation...
The efficacy of a site remediation strategy involving the stimulation microbial U(VI) reduction hinges in part upon long-term stability product, biogenic uraninite, toward environmental oxidants. Geological sedimentary uraninites (nominal formula UO2) reportedly contain abundant cation impurities that enhance their resistance to oxidation. By analogy, incorporation common groundwater solutes into uraninite could also impart stability-enhancing properties. Mn(II) is cation, which has...