The kinetics of Fe-rich intermetallic formation in aluminium alloys: In situ observation

2009 ◽  
Vol 60 (7) ◽  
pp. 516-519 ◽  
Author(s):  
J WANG ◽  
P LEE ◽  
R HAMILTON ◽  
M LI ◽  
J ALLISON
Keyword(s):  
Aluminium Alloys ◽  
In Situ Observation ◽  
Intermetallic Formation ◽  
Kinetics Of

In situ observation of the martensitic transformation in (Mg,Y)-PSZ

1986 ◽  
Vol 44 ◽  
pp. 500-501
Author(s):  
R-R. Lee
Keyword(s):  
Martensitic Transformation ◽  
High Strength ◽  
Nucleation And Growth ◽  
In Situ Observation ◽  
Considerable Potential ◽  
Transmission Electron ◽  
Structural Applications ◽  
Applied Stresses ◽  
Kinetics Of

Partially-stabilized ZrO2 (PSZ) ceramics have considerable potential for advanced structural applications because of their high strength and toughness. These properties derive from small tetragonal ZrO2 (t-ZrO2) precipitates in a cubic (c) ZrO2 matrix, which transform martensitically to monoclinic (m) symmetry under applied stresses. The kinetics of the martensitic transformation is believed to be nucleation controlled and the nucleation is always stress induced. In situ observation of the martensitic transformation using transmission electron microscopy provides considerable information about the nucleation and growth aspects of the transformation.

Highly explosive basaltic eruptions: magma fragmentation induced by rapid crystallisation

2020 ◽  
Author(s):  
Fabio Arzilli ◽  
Giuseppe La Spina ◽  
Mike R. Burton ◽  
Margherita Polacci ◽  
Nolwenn Le Gall ◽  
...  
Keyword(s):  
Ex Situ ◽  
Explosive Eruptions ◽  
In Situ Observation ◽  
Sudden Increase ◽  
Crystallisation Kinetics ◽  
Magma Fragmentation ◽  
Crystallization Experiments ◽  
Basaltic Magmas ◽  
Kinetics Of

<p>Basaltic eruptions are the most common form of volcanism on Earth and planetary bodies. The low viscosity of basaltic magmas generally favours effusive and mildly explosive volcanic activity. Highly explosive basaltic eruptions occur less frequently and their eruption mechanism still remains subject to debate, with implications for the significant hazard associated with explosive basaltic volcanism. Particularly, highly explosive eruptions require magma fragmentation, yet it is unclear how basaltic magmas can reach the fragmentation threshold.</p><p>In volcanic conduits, the crystallisation kinetics of an ascending magma are driven by degassing and cooling. So far, the crystallisation kinetics of magmas have been estimated through ex situ crystallization experiments. However, this experimental approach induces underestimation of crystallization kinetics in silicate melts. The   crystallization experiments reported in this study were performed in situ at Diamond Light Source (experiment EE12392 at the I12 beamline), Harwell, UK, using basalt from the 2001 Etna eruption as the starting material. We combined a bespoke high-temperature environmental cell with fast synchrotron X-ray microtomography to image the evolution of crystallization in real time. After 4 hours at sub-liquidus conditions (1170 °C and 1150 °C) the system was perturbed through a rapid cooling (0.4 °C/s), inducing a sudden increase of undercooling. Our study reports the first in situ observation of exceptionally rapid plagioclase and clinopyroxene crystallisation in trachybasaltic magmas. We combine these constraints on crystallisation kinetics and viscosity evolution with a numerical conduit model to show that exceptionally rapid syn-eruptive crystallisation is the fundamental process required to trigger basaltic magma fragmentation under high strain rates. Our in situ experimental and natural observations combined with a numerical conduit model allow us to conclude that pre-eruptive temperatures <1,100°C can promote highly explosive basaltic eruptions, such as Plinian volcanism, in which fragmentation is induced by fast syn-eruptive crystal growth under high undercooling and high decompression rates. This implies that all basaltic systems on Earth have the potential to produce powerful explosive eruptions.</p>

scholarly journals In-situ observation microstructure evolution and growth kinetics of lamellar γ phases in Ti44Al alloy during heat treatment

2020 ◽  
Vol 9 (6) ◽  
pp. 12157-12166 ◽  
Author(s):  
Yangli Liu ◽  
Xiang Xue ◽  
Hongze Fang ◽  
Yingmei Tan ◽  
Ruirun Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Growth Kinetics ◽  
Microstructure Evolution ◽  
In Situ Observation ◽  
Kinetics Of

scholarly journals In Situ Continuous Wave Electron Paramagnetic Resonance Investigation of the Amyloid Aggregation of Parkinson’s Protein Alpha-Synuclein—the Second Spin-Label Position

2021 ◽  
Author(s):  
Enrico Zurlo ◽  
Leonardo Passerini ◽  
Pravin Kumar ◽  
Martina Huber
Keyword(s):  
Spin Label ◽  
Continuous Wave ◽  
Alpha Synuclein ◽  
Local Information ◽  
In Situ Observation ◽  
Paramagnetic Resonance ◽  
Electron Paramagnetic Resonance Investigation ◽  
Electron Paramagnetic ◽  
Kinetics Of

AbstractSelf-aggregation of amyloid proteins is a crucial step in neurodegenerative disease. The protein alpha-synuclein (αS) is implicated in Parkinson’s disease. In an extension of the demonstration of in situ observation of intermediates in αS-aggregation by continuous wave (cw) EPR at room temperature (Zurlo et al. PLoS One 16: e0245548, 2021) by spin-label EPR, here the spin label is attached to position 90 (R1αS90), rather than at position 56. The aim is to determine, if the spin-label position affects the kinetics of aggregation and if local information on the intermediates is accessible. Probed by the MTSL ((1-Oxyl-2,2,5,5-tetramethylpyrroline-3-methyl) methanethiosulfonate) spin label at position 90, using diamagnetic dilution of 9:1 wild type αS to R1αS90, similar aggregation kinetics are found. Rotation correlation times for the spin label in the oligomer cannot be determined with sufficient accuracy to obtain local information on the oligomer under the conditions used. At the present stage, higher resolution EPR approaches, such as high-field EPR are more promising.

Influence of the supersaturation on the nucleation-growth process of scale electrodeposition by in situ observation through a transparent quartz crystal microbalance

2004 ◽  
Vol 49 (2) ◽  
pp. 145-152 ◽  
Author(s):  
O. Devos ◽  
C. Gabrielli ◽  
B. Tribollet
Keyword(s):  
Growth Process ◽  
Quartz Crystal ◽  
Pure Water ◽  
In Situ Observation ◽  
Nucleation Process ◽  
Mass Measurements ◽  
Kinetics Of ◽  
Scale Deposition ◽  
Nucleation Growth

An original technique allowed three in situ measurements to be obtained simultaneously, i.e. electrochemical and mass measurements and a microscope image of the interface between electrode and solution. The nucleation-growth process of CaCO3 deposition was investigated by varying different parameters which influenced the supersaturation coefficient, the Ca2+ concentration, pH and convection of the carbonically pure water near the substrate. The results showed that the variation of the scaling rate was due, for the two first cases, to an influence of the nucleation process whereas for the last case, the kinetics of scale deposition were modified by a shift of the growth rate.

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