scholarly journals High Sorption and Selective Extraction of Actinides from Aqueous Solutions

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7101
Author(s):  
Linfa Bao ◽  
Yawen Cai ◽  
Zhixin Liu ◽  
Bingfeng Li ◽  
Qi Bian ◽  
...  
Keyword(s):  
Natural Environment ◽  
Theoretical Calculations ◽  
Near Field ◽  
Interaction Mechanism ◽  
Selective Extraction ◽  
Solid Particles ◽  
Natural Clay ◽  
Selective Elimination ◽  
High Sorption ◽  
Waste Repositories

The selective elimination of long-lived radioactive actinides from complicated solutions is crucial for pollution management of the environment. Knowledge about the species, structures and interaction mechanism of actinides at solid–water interfaces is helpful to understand and to evaluate physicochemical behavior in the natural environment. In this review, we summarize recent works about the sorption and interaction mechanism of actinides (using U, Np, Pu, Cm and Am as representative actinides) on natural clay minerals and man-made nanomaterials. The species and microstructures of actinides on solid particles were investigated by advanced spectroscopy techniques and computational theoretical calculations. The reduction and solidification of actinides on solid particles is the most effective way to immobilize actinides in the natural environment. The contents of this review may be helpful in evaluating the migration of actinides in near-field nuclear waste repositories and the mobilization properties of radionuclides in the environment.

scholarly journals Research of friction characteristics on the hydraulic transportation in inclined slurry-pipe

2020 ◽  
Vol 198 ◽  
pp. 01030
Author(s):  
Wang Tieli
Keyword(s):  
Experimental Data ◽  
Momentum Transfer ◽  
Interaction Mechanism ◽  
Hydraulic Gradient ◽  
Solid Particles ◽  
Friction Loss ◽  
Acceleration Time ◽  
New Model ◽  
Inclined Pipe ◽  
Inclined Pipes

By analyzing the momentum transfer and velocity both of solid particles and water over the acceleration time of solid particles, as well as interaction mechanism between water and solid particals, a new model is proposed to predict friction loss for setting slurry flow in inclined pipe. The hydraulic gradient formula for inclined pipes summarized by the author is confirmed by a large amount of experimental data. The results show that the deviation between the theoretical value of the model proposed by the author and the measured value is not more than 13.33%, which is the smallest among all reports.

scholarly journals Probing surface interactions of underwater oleophobic polyelectrolyte multilayers

2020 ◽  
Author(s):  
Kai Li ◽  
Wei Wang ◽  
Zhi-Peng Yu ◽  
Hang Jin ◽  
Yun-Tong Ge ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Interaction Mechanism ◽  
Polyelectrolyte Multilayers ◽  
Layer By Layer ◽  
Surface Wetting ◽  
Force Microscopy ◽  
Atomic Force ◽  
Layer Deposition ◽  
Nacl Concentration ◽  
Force Curves

Abstract In the present work, the interaction mechanism of specific polyelectrolyte multilayers (PEMs), fabricated by layer-by-layer deposition of polydiallyldimethylammonium chloride (PDDA) and poly(sodium 4-styrenesulfonate) (PSS), is studied using atomic force microscopy. The underwater oil-repellency of PSS-capped PEMs was further explored by measuring the interaction forces between tetradecane droplets and PEMs-coated silica substrates under various salinities. The force curves were analyzed following the Stokes–Reynolds–Young–Laplace theoretical model. Desirable consistency was achieved between the experimental and theoretical calculations at low NaCl concentrations (0.1 mM and 1 mM); however, underestimation of the attractive force was found as the NaCl concentration increases to moderate (10 mM) and high (100 mM) levels. Discrepancy analyses and incorporated features toward a reduced surface charge density were considered based on the previous findings of the orientation of anionic benzenesulfonate moieties (Liu et al. in Angew Chem Int Ed 54(16):4851–4856, 2015. https://doi.org/10.1002/anie.201411992). Short-range steric hindrance interactions were further introduced to simulate “brush” effect stemming from nanoscale surface roughness. It is demonstrated in our work that the PSS-capped PEMs remains a stable underwater lipophobicity against high salinity, which renders it potential application in surface wetting modification and anti-fouling.

scholarly journals Towards rational design and optimization of near-field enhancement and spectral tunability of hybrid core-shell plasmonic nanoprobes

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Debadrita Paria ◽  
Chi Zhang ◽  
Ishan Barman
Keyword(s):  
Single Molecule ◽  
Rational Design ◽  
Near Infrared ◽  
Theoretical Calculations ◽  
Near Field ◽  
Field Enhancement ◽  
Infrared Region ◽  
Core Shell ◽  
Optimization Strategy ◽  
Design And Optimization

Abstract In biology, sensing is a major driver of discovery. A principal challenge is to create a palette of probes that offer near single-molecule sensitivity and simultaneously enable multiplexed sensing and imaging in the “tissue-transparent” near-infrared region. Surface-enhanced Raman scattering and metal-enhanced fluorescence have shown substantial promise in addressing this need. Here, we theorize a rational design and optimization strategy to generate nanostructured probes that combine distinct plasmonic materials sandwiching a dielectric layer in a multilayer core shell configuration. The lower energy resonance peak in this multi-resonant construct is found to be highly tunable from visible to the near-IR region. Such a configuration also allows substantially higher near-field enhancement, compared to a classical core-shell nanoparticle that possesses a single metallic shell, by exploiting the differential coupling between the two core-shell interfaces. Combining such structures in a dimer configuration, which remains largely unexplored at this time, offers significant opportunities not only for near-field enhancement but also for multiplexed sensing via the (otherwise unavailable) higher order resonance modes. Together, these theoretical calculations open the door for employing such hybrid multi-layered structures, which combine facile spectral tunability with ultrahigh sensitivity, for biomolecular sensing.

Assessment of Redox Conditions in the Near Field of Nuclear Waste Repositories: Application to the Swiss high-level and intermediate level waste disposal concept

2003 ◽  
Vol 807 ◽  
Author(s):  
Paul Wersin ◽  
Lawrence H. Johnson ◽  
Bernhard Schwyn
Keyword(s):  
Solid Phase ◽  
Near Field ◽  
Intermediate Level ◽  
Redox Conditions ◽  
High Level Waste ◽  
Redox Potentials ◽  
Spent Fuel ◽  
Reducing Conditions ◽  
High Level ◽  
Waste Repositories

ABSTRACTRedox conditions were assessed for a spent fuel and high-level waste (SF/HLW) and an intermediate-level waste (ILW) repository. For both cases our analysis indicates permanently reducing conditions after a relatively short oxic period. The canister-bentonite near field in the HLW case displays a high redox buffering capacity because of expected high activity of dissolved and surface-bound Fe(II). This is contrary to the cementitious near field in the ILW case where concentrations of dissolved reduced species are low and redox reactions occur primarily via solid phase transformation processes.For the bentonite-canister near field, redox potentials of about -100 to -300 mV (SHE) are estimated, which is supported by recent kinetic data on U, Tc and Se interaction with reduced iron systems. For the cementitious near field, redox potentials of about -200 to -800 mV are estimated, which reflects the large uncertainties related to this alkaline environment.

Laser Writing of Nanostructures on Magnetic Film Surfaces With Optical Near Field Effects

2001 ◽  
Vol 697 ◽  
Author(s):  
S. M. Huang ◽  
M. H. Hong ◽  
B. S. Luk'yanchuk ◽  
W. D. Song ◽  
Y. F. Lu ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Near Field ◽  
Resonance Effect ◽  
Field Enhancement ◽  
Magnetic Film ◽  
Original Position ◽  
Single Shot ◽  
Optical Resonance ◽  
Field Effects ◽  
Laser Fluences

AbstractLaser directly writing of nanostrucrures on magnetic film surfaces with optical near field effects has been investigated. Spherical 0.99 m or 0.47 m silica particles were placed on Cr/CoCrPt multilayers. After laser illumination with an excimer laser for a single shot, pits were obtained at the original position of the particles using different laser fluences or particle size parameters. The mechanism of the formation of nanostructure pattern was discussed and found to be the near-field optical resonance effect induced by particles on the surface. A comparison with accurate theoretical calculations of near-field light intensity distribution showed good agreement with the experiment results. The method of particle enhanced laser irradiation allows the study of field enhancement effects as well as its potential applications for nanolithography.

scholarly journals Multibarrier system preventing migration of radionuclides from radioactive waste repository

Nukleonika ◽  
2015 ◽  
Vol 60 (3) ◽  
pp. 557-563 ◽  
Author(s):  
Wioleta Olszewska ◽  
Agnieszka Miśkiewicz ◽  
Grażyna Zakrzewska-Kołtuniewicz ◽  
Leszek Lankof ◽  
Leszek Pająk
Keyword(s):  
Radioactive Waste ◽  
Near Field ◽  
Storage Site ◽  
Radionuclide Migration ◽  
Radioactive Waste Repository ◽  
Geological Barrier ◽  
Radioactive Waste Repositories ◽  
Waste Repository ◽  
Waste Repositories ◽  
Migration Modeling

Abstract Safety of radioactive waste repositories operation is associated with a multibarrier system designed and constructed to isolate and contain the waste from the biosphere. Each of radioactive waste repositories is equipped with system of barriers, which reduces the possibility of release of radionuclides from the storage site. Safety systems may differ from each other depending on the type of repository. They consist of the natural geological barrier provided by host rocks of the repository and its surroundings, and an engineered barrier system (EBS). The EBS may itself comprise a variety of sub-systems or components, such as waste forms, canisters, buffers, backfills, seals and plugs. The EBS plays a major role in providing the required disposal system performance. It is assumed that the metal canisters and system of barriers adequately isolate waste from the biosphere. The evaluation of the multibarrier system is carried out after detailed tests to determine its parameters, and after analysis including mathematical modeling of migration of contaminants. To provide an assurance of safety of radioactive waste repository multibarrier system, detailed long term safety assessments are developed. Usually they comprise modeling of EBS stability, corrosion rate and radionuclide migration in near field in geosphere and biosphere. The principal goal of radionuclide migration modeling is assessment of the radionuclides release paths and rate from the repository, radionuclides concentration in geosphere in time and human exposure to ionizing radiation

Modeled Near-Field Environment Porosity Modification due to Coupled Thermohydrologic and Geochemical Processes

1999 ◽  
Vol 556 ◽  
Author(s):  
John J. Nitao ◽  
William E. Glassley
Keyword(s):  
Reactive Transport ◽  
Near Field ◽  
Mineral Dissolution ◽  
Rock Properties ◽  
Actual Distribution ◽  
Porosity Reduction ◽  
Field Environment ◽  
Flow Pathways ◽  
Waste Repositories ◽  
Dissolution And Precipitation

AbstractHeat generated by waste packages in nuclear waste repositories can modify rock properties by instigating mineral dissolution and precipitation along hydrothermal flow pathways. Modeling this reactive transport requires coupling fluid flow to permeability changes resulting from dissolution and precipitation. Modification of the NUFT thermohydrologic (TH) code package to account for this coupling in a simplified geochemical system has been used to model the timedependent change in porosity, permeability, matrix and fracture saturation, and temperature in the vicinity of waste-emplacement drifts, using conditions anticipated for the potential Yucca Mountain repository. The results show dramatic porosity reduction approximately 10 m above emplacement drifts within a few hundred years. Most of this reduction is attributed to deposition of solute load at the boiling front, although some of it also results from decreasing temperature along the flow path. The actual distribution of the nearly sealed region is sensitive to the time-dependent characteristics of the thermal load imposed on the environment and suggests that the geometry of the sealed region can be engineered by managing the waste-emplacement strategy and schedule.

scholarly journals Mesoscale Acoustical Cylindrical Superlens

2018 ◽  
Vol 155 ◽  
pp. 01029 ◽  
Author(s):  
Igor Minin ◽  
Oleg Minin
Keyword(s):  
Wave Scattering ◽  
Near Field ◽  
Elastic Solid ◽  
Diffraction Limit ◽  
Solid Particles ◽  
Acoustic Metamaterials ◽  
Field Zone ◽  
Sharp Focusing ◽  
Plane Wave Scattering ◽  
First Time

We demonstrate experimentally for the first time the acoustojet (acoustic jets) formed from acoustic plane wave scattering by a penetrable cylindrical particle with dimensions of several wavelengths. It acts as a superlens with subwavelength localization of acoustical wave. During the scattering by elastic solid particles, additional internal shear waves are excited due to modes conversion. This mechanism allows achieving sharp focusing in the near-field zone. Such mesoscale single particle cylindrical lens may be considered as acoustic metamaterials free superlenses with resolution beyond the diffraction limit.

scholarly journals Carbon nanotubes functionalized with copper hexacyanoferrate nanoparticles for a selective extraction of cesium from liquid waste

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
H. Draouil ◽  
L. Alvarez ◽  
J. Causse ◽  
V. Flaud ◽  
M.A. Zaibi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Copper Ions ◽  
Liquid Waste ◽  
Single Walled Carbon Nanotubes ◽  
Selective Extraction ◽  
Carbon Supports ◽  
Copper Hexacyanoferrate ◽  
Single Walled Carbon ◽  
High Sorption ◽  
Walled Carbon Nanotubes

Single-walled carbon nanotubes are functionalized with copper hexacyanoferrate nanoparticles for the liquid-solid extraction of cesium from liquid waste and contaminated water. The functionalization process is followed mainly by x-ray photoemission spectroscopy. Indeed, determining the chemical environment around carbon or nitrogen atoms allows to evidence the formation of covalent bounding. In addition, the signatures of iron and copper ions give information on the effective growth of hexacyanoferrate nanoparticles. Furthermore, the cesium sorption mechanism is investigated by comparing the peak intensities associated to the response of potassium and cesium ions. Finally, based on the liquid chromatography analyzes, the sorption of cesium with the functionalized carbon supports is studied. The main results of this work are the demonstration of both a good selectivity of cesium trapping and a high sorption capacity by hybrid single-walled carbon nanotubes.

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