Up-Conversion in Yb,Er-Doped Y2O3 Nanoparticles for Cell Imaging

2007 ◽  
Vol 555 ◽  
pp. 383-388 ◽  
Author(s):  
Aurelie Bessière ◽  
Fabienne Pellé ◽  
Claire Mathieu ◽  
Bruno Viana ◽  
Philippe Vermaut
Keyword(s):  
Particle Size ◽  
Combustion Synthesis ◽  
Cell Imaging ◽  
Small Particles ◽  
Emission Efficiency ◽  
Direct Excitation ◽  
Er Doped

Y2O3:19%Yb,1%Er nanoparticles were synthesized with the aim of imaging the luminescent cell. Coprecipitation and combustion synthesis were used to obtain particulate sizes ranging from 25 up to 140 nm. The powders showed predominant red upconversion and the emission efficiency is controlled by the particle size. A colloidal route was also followed and 2-5 nm-large agglomerated nanoparticles were obtained. In that case, the luminescence of Er3+ was only observed by direct excitation and no upconversion light has been detected on these very small particles.

scholarly journals Comparison of the Bone Harvesting Capacity of an Intraoral Bone Harvesting Device and Three Different Implant Drills

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Hyun-Chang Lim ◽  
Kyung-In Ha ◽  
Ji-Youn Hong ◽  
Ji-Young Han ◽  
Seung-Il Shin ◽  
...  
Keyword(s):  
Particle Size ◽  
Dry Weight ◽  
Volumetric Measurement ◽  
Small Particles ◽  
Low Speed ◽  
Bone Particle ◽  
Bone Harvesting ◽  
Bone Particles

The aim of the present study was to compare bone-collecting capacity of bone harvesting device and minimally irrigated low-speed drilling using three implant systems. One bone harvesting device and three commercially available drill systems were compared using the osteotomies on bovine rib bones. The amount of the collected bone particle and particle size (<500 μm: small, 500–1000 μm: medium, and >1000 μm: large) were measured. Total wet (1.535±0.232 mL) and dry volume (1.147±0.425 mL) of the bone particles from bone harvesting device were significantly greater than three drill systems (wet volume: 1.225±0.187–1.27±0.29 mL and dry volume: 0.688±0.163–0.74±0.311 mL) (P<0.05). In all groups, the amount of large sized particles in wet and dry state was the greatest compared to that of medium and small particles. The dry weight of the bone particles showed the same tendency to volumetric measurement. In conclusion, total bone particles and large sized particles (>1000 μm) were harvested significantly greater by bone harvesting device than minimally irrigated low-speed drilling. The composition of particle size in all harvesting methods was similar to each other.

A Convenient Method for Preparing Well-Dispersed Er2Zr2O7 Nanocrystals

2010 ◽  
Vol 123-125 ◽  
pp. 611-614 ◽  
Author(s):  
Yu Ping Tong ◽  
Rui Zhu Zhang ◽  
Shun Bo Zhao ◽  
Chang Yong Li
Keyword(s):  
Particle Size ◽  
Combustion Synthesis ◽  
Crystal Size ◽  
Lattice Distortion ◽  
Combustion Method ◽  
Treatment Temperature ◽  
Synthesis Process ◽  
Thermal Treatment Temperature ◽  
Average Size ◽  
Xrd And Tem

Well-dispersed fluorite Er2Zr2O7 nanocrystals have been successfully prepared by a convenient salt-assistant combustion method. The effects of calcinations temperature and salt category on the characteristics of the products were investigated by XRD and TEM. The thermal treatment temperature has an important effect on crystal size and lattice distortion of the nanocrystals. The experiment showed that the introduction of salt in the combustion synthesis process resulted in the formation of well-dispersed Er2Zr2O7 nanocrystals. The average size was 30 nm and was in agreement with the XRD result, which indicated that the nanocrystals were uniform in particle size distribution. Moreover, the possible formation process in the salt-assisted combustion synthesis was also analyzed.

Combustion Synthesis of Nanostructured ZrC: Formation Process and Influencing Factors

2021 ◽  
Vol 21 (4) ◽  
pp. 2196-2202
Author(s):  
Xian-Rui Zhao ◽  
Dun-Wen Zuo ◽  
Yong Chen ◽  
Qin-Tao Li ◽  
Gui-Xiang Liu ◽  
...  
Keyword(s):  
Particle Size ◽  
Combustion Synthesis ◽  
Influencing Factors ◽  
Combustion Wave ◽  
Formation Process ◽  
Combustion Temperature ◽  
Ceramic Particle ◽  
Displacement Reaction ◽  
Synthesis Mechanism ◽  
By Products

ZrC was produced by the combustion synthesis technology using Cu, Zr, and graphite as the starting element powders. The synthesis mechanism of ZrC was investigated by the combustion wave quenching experiment. Furthermore, the effects of sizes of C and Cu on the combustion synthesis behavior and products were also explored. Results revealed that ZrC was fabricated through the displacement reaction between C and Cu–Zr liquid. The Cu size hardly affected the combustion temperature and resultant products, indicating that the preparation cost of ZrC could be decreased by employing coarse Cu powders. With increasing C size, the burning temperature and ceramic particle size reduced. Graphite with size of 2.6 μm was used as the C source, and only ZrC nanoparticles and Cu were obtained. The products could be employed to prepare nano-sized ZrC/Cu composites without the elimination of by-products.

Dispersion of Particles on Liquid Surfaces

2011 ◽  
Author(s):  
Shriram B. Pillapakkam ◽  
Pushpendra Singh
Keyword(s):  
Numerical Simulation ◽  
Particle Size ◽  
Vertical Motion ◽  
Liquid Interface ◽  
Water Interface ◽  
Small Particles ◽  
Air Water Interface ◽  
Large Velocity ◽  
Simulation Results ◽  
Air Liquid Interface

In a recent study we have shown that when small particles, e.g., flour, pollen, glass, etc., contact an air-liquid interface, they disperse rapidly as if they were in an explosion. The rapid dispersion is due to the fact that the capillary force pulls particles into the interface causing them to accelerate to a large velocity. The vertical motion of a particle during its adsorption causes a radially-outward lateral (secondary) flow on the interface that causes nearby particles to move away. We present direct numerical simulation results for the adsorption of particles and show that the inertia of a particle plays an important role in its motion in the direction normal to a fluid-liquid interface. Although the importance of inertia diminishes with decreasing particle size, on an air-water interface the inertia continues to be important even when the size is as small as a few nanometers.

SIZE-DEPENDENT UPCONVERSION PROPERTIES OF Er3+ DOPED NANO Y2O3 PARTICLES

2011 ◽  
Vol 25 (04) ◽  
pp. 265-272 ◽  
Author(s):  
SIGUO XIAO ◽  
XIAOLIANG YANG
Keyword(s):  
Particle Size ◽  
Intensity Ratio ◽  
Radiative Decay ◽  
Luminescence Properties ◽  
Small Particles ◽  
Decay Probability ◽  
Size Dependent ◽  
Energy Transfers ◽  
Nano Crystal

Size-dependent upconversion properties for Er 3+-doped Y 2 O 3 nano-crystal have been investigated. The investigation shows that the reduction of the particle size intensifies the hypersensitive 2 H 11/2 → 4 I 15/2 transition, decreasing the intensity ratio of the 4 S 3/2 → 4 I 15/2 transition to the 2 H 11/2 → 4 I 15/2 one. The enhanced non-radiative decay probability and the intensified energy transfers in the small particles also enhance the population of the 4 F 9/2 level, leading to the increase of the intensity ratio of the red to the green one. It is believed that the absorbed hydroxyl and carbonate groups on the surface as well as the lowered symmetry of the local surroundings of the doped Er 3+ ions near the surface result in the size-dependent luminescence properties in the nano-crystal.

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