Carrier-Free Separation of the Individual Rare Earth Radionuclides from Fission Product Mixtures

1963 ◽  
Author(s):  
L. Wish ◽  
S. C. Foti
Keyword(s):  
Rare Earth ◽  
Fission Product ◽  
Carrier Free ◽  
The Individual

scholarly journals Nanophosphors-Based White Light Sources

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 1048 ◽  
Author(s):  
Maura Cesaria ◽  
Baldassare Di Bartolo
Keyword(s):  
Rare Earth ◽  
White Light ◽  
Volume Ratio ◽  
Light Sources ◽  
Co Doping ◽  
New Class ◽  
Luminescence Efficiency ◽  
Metal Doped ◽  
The Individual ◽  
The Impact

Miniaturization requests and progress in nanofabrication are prompting worldwide interest in nanophosphors as white-emission mercury-free lighting sources. By comparison with their bulk counterparts, nanophosphors exhibit reduced concentration quenching effects and a great potential to enhance luminescence efficiency and tunability. In this paper, the physics of the nanophoshors is overviewed with a focus on the impact of spatial confinement and surface-to-volume ratio on the luminescence issue, as well as rare earth-activated multicolor emission for white light (WL) output. In this respect, the prominently practiced strategies to achieve WL emission are single nanophosphors directly yielding WL by means of co-doping and superposition of the individual red, green, and blue emissions from different nanophosphors. Recently, a new class of efficient broadband WL emitting nanophosphors has been proposed, i.e., nominally un-doped rare earth free oxide (yttrium oxide, Y2O3) nanopowders and Cr transition metal-doped garnet nanocrystals. In regard to this unconventional WL emission, the main points are: it is strictly a nanoscale phenomenon, the presence of an emitting center may favor WL emission without being necessary for observing it, and, its inherent origin is still unknown. A comparison between such an unconventional WL emission and the existing literature is presented to point out its novelty and superior lighting performances.

Understanding Persistent Luminescence: Rare-Earth- and Eu2+-doped Sr2MgSi2O7

2014 ◽  
Vol 69 (2) ◽  
pp. 171-182 ◽  
Author(s):  
Mika Lastusaari ◽  
Högne Jungner ◽  
Aleksei Kotlov ◽  
Taneli Laamanen ◽  
Lucas C. V. Rodrigues ◽  
...  
Keyword(s):  
Rare Earth ◽  
Band Gap ◽  
Charge Compensation ◽  
Band Gap Energy ◽  
Persistent Luminescence ◽  
Excitation Spectra ◽  
Co Doping ◽  
The Individual ◽  
Initial Intensity ◽  
The Eu

Similar to many other Eu2+,RE3+-co-doped persistent luminescence materials, for Sr2MgSi2O7:Eu2+,RE3+ the initial intensity and duration of persistent luminescence was also found to depend critically on the rare-earth (RE) co-doping. An enhancement of 1 - 2 orders of magnitude in these properties could be obtained by Dy3+ co-doping whereas total quenching of persistent luminescence resulted from the use of Sm3+ and Yb3+. To solve this drastic disparity, the effects of the individual RE3+ ions were studied with thermoluminescence (TL) spectroscopy to derive information about the formation of traps storing the excitation energy. The charge compensation defects were concluded to be the origin of the complex TL glow curve structure. The tuning of the band gap of the Sr2MgSi2O7 host and especially the position of the bottom of the conduction band due to the Eu2+,RE3+ co-doping was measured with the synchrotron radiation vacuum UV (VUV) excitation spectra of the Eu2+ dopant. The model based on the evolution of the band gap energy with RE3+ co-doping was found to explain the intensity and duration of the persistent luminescence.

scholarly journals Ni-Cu-Zn Ferrite Research: A Brief Review

2013 ◽  
Vol 5 (2) ◽  
pp. 215-234 ◽  
Author(s):  
M. F. Huq ◽  
D. K. Saha ◽  
R. Ahmed ◽  
Z. H. Mahmood
Keyword(s):  
Rare Earth ◽  
High Frequency ◽  
Sintering Temperature ◽  
Electromagnetic Properties ◽  
Sintering Aids ◽  
Cu Content ◽  
Zn Concentration ◽  
Zn Ferrite ◽  
The Individual ◽  
Better Than

The temperature at which the ferrite is sintered critically depends on the chemical composition. The electromagnetic properties are dependent on the densification and microstructure. Substitutions and addition of sintering aids is an attractive approach to enhance the electromagnetic properties. Various compositions in the system Ni1-x-yCuxZnyFe2O4 were investigated. Cu is used to decrease the sintering temperature. However, Cu decreases the resistivity, which is not desirable for its high frequency applications. So, optimization of Cu content is necessary. Different ranges of electromagnetic properties have been reported with various Zn concentrations. Optimization of Zn concentration with respect to Ni and Cu is essential to achieve desirable electromagnetic properties. Influence of rare earths has also been reported. The investigations showed an improved densification in Ni-Zn and increased permeability in Cu-Zn ferrite by Sm substitution. La substitutions showed an improved resistivity in Ni-Zn ferrites. Similarly, these substitutions may improve the electromagnetic properties in Ni-Cu-Zn ferrites. V2O5, MoO3 and Bi2O3 were reported to be the most widely used sintering additives. Bi2O3-WO3 and V2O5-MoO3 mixed additives were better than the individual additives in Ni-Cu-Zn ferrite, respectively. Further research is needed on the mixed sintering additivesKeywords: Additives; Ferrite preparation; Ni-Cu-Zn ferrite; Rare Earth; Sintering aids.© 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v5i2.12434 J. Sci. Res. 5 (2), 215-233 (2013)

Research on the High-Power Directional Acoustic Transducer

2014 ◽  
Vol 912-914 ◽  
pp. 753-756
Author(s):  
Guo Zhu Zhao ◽  
Li Xuan Ma
Keyword(s):  
Rare Earth ◽  
Sound Source ◽  
Beam Width ◽  
Directivity Pattern ◽  
Acute Angle ◽  
The Other ◽  
Acoustic Transducer ◽  
Element Number ◽  
The Individual ◽  
Selection Of

Through studying how to affect acoustic directivity with MATLAB software, it show that selection of a relatively larger surface of the transducer and a relatively closer transducer interval will be more preferable for directivity. While an array which possess more array element number and whose frequency of the drive signal can be as large as possible in a range, directivity will be more preferable. On the other hand, when the structure of the sound radiating surface of the transducer or array layout is symmetrical, the corresponding directivity pattern will be symmetrical. At a frequency of 10kHz, the individual rare earth magnetostrictive transducers its first point of the simulation carried out before the test. Sounding board with aluminum by the method used to improve the sound source diameter. With the sound plate diameter incrementing, the smaller the angle of the directivity. The beam width of the 3×3 array is about at 23kHz, and the directivity acute angle is about 10°, with a sounding board by the method used to improve their the diameter of the sound source, so as to realize the sound has directivity is feasible.

Hydrogenation of Nitro Compounds over Catalytic Systems Containing Rare-Earth Oxides

2021 ◽  
Vol 316 ◽  
pp. 684-688
Author(s):  
G. M. Kurunina ◽  
O.M. Ivankina ◽  
G.M. Butov
Keyword(s):  
Rare Earth ◽  
Palladium Catalysts ◽  
Nitro Compounds ◽  
Rare Earth Oxides ◽  
Partial Replacement ◽  
Hydrogenation Rate ◽  
Catalytic Systems ◽  
Liquid Phase Hydrogenation ◽  
The Individual ◽  
Reference Catalyst

The paper studies the activity of 1 % palladium catalysts containing rare earth oxides (REOs) and alumina as a carrier in the hydrogenation of nitro compounds exemplified by nitrobenzene and o-nitro anisole. Under the liquid-phase hydrogenation conditions, these catalytic systems provide high selectivity of the process and a quantitative yield. It has been found that the partial replacement of Al2O3 with REO allows increasing the hydrogenation rate by 5–6 times, as compared with the reference catalyst and by 1.2–1.7 times as compared with the individual carrier. The oxide mixtures (REO and Al2O3) containing 20–40 % REO allow reaching the same hydrogenation rate with that over an REO-containing 1 % Pd catalyst.

scholarly journals Nanosized Pinning Centers in the Rare Earth-Barium-Copper-Oxide Thin-Film Superconductors

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1429 ◽  
Author(s):  
Filip Antončík ◽  
Ondřej Jankovský ◽  
Tomáš Hlásek ◽  
Vilém Bartůněk
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Mixed Oxides ◽  
High Temperature Superconductivity ◽  
Barium Copper Oxide ◽  
Oxide Thin Film ◽  
Pinning Centers ◽  
Barium Copper ◽  
The Individual ◽  
Copper Oxide Thin Film

Since the discovery of high-temperature superconductivity, significant progress in the fabrication of REBCO-based (Rare Earth Barium Copper mixed Oxides) thin-films superconductors has been achieved. In our review, we described the approaches and possibilities of the improvement of superconducting properties by the introduction of nanosized pinning centers. We focused on the synthesis and viability of the material for artificial pinning centers and methods used for the introduction of the pinning centers into superconducting REBCO-based thin-films. This article summarizes available materials and procedures regardless of the financial cost of the individual method. According to available literature, the most significant superconducting REBCO tapes can be obtained when a combination of 1D and 0D nanoparticles are used for nanoscale pinning.

scholarly journals Potencial management of waste phosphogypsum with particular focus on recovery of rare earth metals

2015 ◽  
Vol 17 (1) ◽  
pp. 55-61 ◽  
Author(s):  
Kinga Podbiera-Matysik ◽  
Katarzyna Gorazda ◽  
Zbigniew Wzorek
Keyword(s):  
Rare Earth ◽  
Industrial Waste ◽  
Rare Earth Metals ◽  
Construction Materials ◽  
Calcium Sulphate ◽  
Individual Characteristics ◽  
Economic Problems ◽  
Global Environmental ◽  
The Individual ◽  
The Given

Abstract Phosphogypsum is a noxious industrial waste contributing to global environmental and economic problems. This publication focuses above all on phosphogypsum resulting from the processing of apatite as a phosphorus bearing compound, since it contains considerable amounts of lanthanides due to its magma origin. The possibilities of its waste-free processing are large, however they require the application of suitable technologies, frequently expensive ones, and allowing for the individual characteristics of the given waste. The research works conducted so far confirm the possibility of applying phosphogypsum for the recovery of lanthanides, and the process enhances the removal of remaining impurities, thanks to which the purified calcium sulphate (gypsum) may find application for the production of construction materials.

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