scholarly journals Nano-Scale Hydroxyapatite: Synthesis, Two-Dimensional Transport Experiments, and Application for Uranium Remediation

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
S. R. Kanel ◽  
T. P. Clement ◽  
M. O. Barnett ◽  
M. N. Goltz
Keyword(s):  
Complete Removal ◽  
Saturated Porous Media ◽  
Two Dimensional ◽  
Tracer Transport ◽  
Flow Conditions ◽  
X Ray Diffraction ◽  
Nano Scale ◽  
Groundwater Systems ◽  
Transport Patterns

Synthetic nano-scale hydroxyapatite (NHA) was prepared and characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. The XRD data confirmed that the crystalline structure and chemical composition of NHA correspond to Ca5OH(PO4)3. The SEM data confirmed the size of NHA to be less than 50 nm. A two-dimensional physical model packed with saturated porous media was used to study the transport characteristics of NHA under constant flow conditions. The data show that the transport patterns of NHA were almost identical to tracer transport patterns. This result indicates that the NHA material can move with water like a tracer, and its movement was neither retarded nor influenced by any physicochemical interactions and/or density effects. We have also tested the reactivity of NHA with 1 mg/L hexavalent uranium (U(VI)) and found that complete removal of U(VI) is possible using 0.5 g/L NHA at pH 5 to 6. Our results demonstrate that NHA has the potential to be injected as a dilute slurry forin situtreatment of U(VI)-contaminated groundwater systems.

Thermally boosted upconversion and downshifting luminescence in Sc2(MoO4)3:Yb/Er with two-dimensional negative thermal expansion

2021 ◽  
Author(s):  
Jinsheng Liao ◽  
Minghua Wang ◽  
Fulin Lin ◽  
Zhuo Han ◽  
Datao Tu ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Near Infrared ◽  
Negative Thermal Expansion ◽  
Thermal Quenching ◽  
Relative Sensitivity ◽  
Strong Temperature Dependence ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Higher Temperature

Abstract Lanthanide (Ln3+)-doped phosphors generally suffer from thermal quenching, in which their photoluminescence (PL) intensities decrease at the higher temperature. Herein, we report a class of unique two-dimensional negative-thermal-expansion phosphor of Sc2(MoO4)3:Yb/Er. By virtue of the reduced distances between sensitizers and emitters as well as confined energy migration with increasing the temperature, a 45-fold enhancement of green upconversion (UC) luminescence and a 450-fold enhancement of near-infrared downshifting (DS) luminescence of Er3+ are achieved from 25 to 500 ˚C. The thermally boosted UC and DS luminescence mechanism is systematically investigated through in situ temperature-dependent Raman spectroscopy, synchrotron X-ray diffraction and PL dynamics. Moreover, the luminescence lifetime of 4I11/2 of Er3+ in Sc2(MoO4)3:Yb/Er displays a strong temperature dependence, enabling ratiometric thermometry with the highest relative sensitivity of 13.4%/K at 298 K. These findings may gain a vital insight into the design of negative-thermal-expansion Ln3+-doped phosphors for versatile applications.

Evolution of implicate order from amorphous to polycrystalline Sn-doped In2O3 films determined by in situ two-dimensional X-ray diffraction measurements

2020 ◽  
Vol 13 (6) ◽  
pp. 065502
Author(s):  
Yutaka Furubayashi ◽  
Shintaro Kobayashi ◽  
Makoto Maehara ◽  
Kazuhiko Ishikawa ◽  
Katsuhiko Inaba ◽  
...  
Keyword(s):  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Implicate Order

Surface Structure of LiNi0.8Co0.2O2: a New Experimental Technique Using in Situ X-ray Diffraction and Two-Dimensional Epitaxial Film Electrodes

2009 ◽  
Vol 21 (13) ◽  
pp. 2632-2640 ◽  
Author(s):  
Kazuyuki Sakamoto ◽  
Masaaki Hirayama ◽  
Noriyuki Sonoyama ◽  
Daisuke Mori ◽  
Atsuo Yamada ◽  
...  
Keyword(s):  
Surface Structure ◽  
Experimental Technique ◽  
Epitaxial Film ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray

A 1000°C furnace forin situX-ray diffraction

2001 ◽  
Vol 34 (5) ◽  
pp. 677-678 ◽  
Author(s):  
Anna Puig-Molina ◽  
Bernard Gorges ◽  
Heinz Graafsma
Keyword(s):  
Solid State ◽  
Detector System ◽  
Solid State Reactions ◽  
Controlled Atmosphere ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Geometry ◽  
Melting And Crystallization

A furnace covering the temperature range from 25 to 1000°C has been designed and constructed to studyin situsolid-state reactions and melting and crystallization processes, with X-ray diffraction in transmission geometry using a two-dimensional-detector system. The oven can work in low vacuum and under a controlled atmosphere.

In-Situ X-ray Diffraction as a Tool to Probe Mechanical Phenomena Down to the Nano-Scale

2006 ◽  
Vol 8 (11) ◽  
pp. 1084-1088
Author(s):  
J. Keckes ◽  
E. Eiper ◽  
K. J. Martinschitz ◽  
P. Boesecke ◽  
W. Gindl ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Nano Scale ◽  
Mechanical Phenomena

Aging-time-resolvedin situmicrostructural investigation of tin films electroplated on copper substrates, applying two-dimensional-detector X-ray diffraction

2013 ◽  
Vol 46 (6) ◽  
pp. 1645-1653 ◽  
Author(s):  
Jendrik Stein ◽  
Udo Welzel ◽  
Werner Huegel ◽  
Sabine Blatt ◽  
Eric Jan Mittemeijer
Keyword(s):  
Diffraction Method ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Sn Whisker ◽  
Grain Rotation ◽  
Tin Films ◽  
X Ray ◽  
Layer Deposition ◽  
Growth Phenomenon

Pure thin tin films, electroplated on copper substrates, were investigated byin situX-ray diffraction analysis during room-temperature aging, using a laboratory diffractometer equipped with a two-dimensional detector. Diffraction spots of single Sn grains in the Sn film could be observed and traced over time by using the diffraction method adopted. For the as-deposited specimens, striking changes of the Sn reflection spots, concerning their position and intensity, as well as sudden appearances and disappearances of additional diffraction spots, were observed. This could be ascribed to local microstructural changes in the films such as grain rotation, grain growth and grain dissolution. In contrast to the as-deposited specimens, so-called post-baked specimens (i.e.annealed at 423 K for 1 h after layer deposition) exhibited a stable microstructure. The results obtained are discussed with respect to their relevance for the Sn whisker-growth phenomenon.

In situ structural analysis of BPDA-PPD polyimide thin film using two-dimensional grazing incidence X-ray diffraction

2008 ◽  
Vol 23 (2) ◽  
pp. 109-112 ◽  
Author(s):  
J. Kikuma ◽  
T. Nayuki ◽  
T. Ishikawa ◽  
S. Matsuno ◽  
G. Asano
Keyword(s):  
Thin Film ◽  
Grazing Incidence ◽  
Molecular Chain ◽  
Curing Temperature ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Cooling Process ◽  
X Ray ◽  
Plane Direction

Structural development of BPDA-PPD polyimide thin film has been investigated by in situ grazing incidence X-ray diffraction at the BL24XU beamline of the SPring-8. Optimizing the sample shape, two-dimensional images were measured successfully without sacrificing angle resolution. It has been clearly shown that the crystallization first begins in the in-plane direction, at the curing temperature of 180 °C, in which the periodic structure of the molecular chain axis (c axis) is developed. The crystallization in the surface normal (out-of-plane) direction is observed later, at the curing temperature above 300 °C. A slight increase of the d spacing of the c axis during heating process has been observed, suggesting the stretching of the contracted molecular chain in accordance with the curing process. In the cooling process, the decrease of the d spacings for a and b axes was considerable, which indicates thermal expansion of the crystals at high temperatures. The increases in the peak intensities during the cooling process have been observed, which indicate the d spacing of each axis becomes close to the equilibrium value to produce higher periodicity.

Sign in / Sign up

Export Citation Format

Share Document