A simplified rapid-quench multi-anvil technique

2021 ◽  
Vol 92 (11) ◽  
pp. 113902
Author(s):  
Dmitry Bondar ◽  
Hongzhan Fei ◽  
Anthony C. Withers ◽  
Takayuki Ishii ◽  
Artem Chanyshev ◽  
...  
Keyword(s):  
Rapid Quench

METGLAS ALLOY 2826

Alloy Digest ◽  
1976 ◽  
Vol 25 (11) ◽  
Keyword(s):  
Magnetic Properties ◽  
Metallic Glass ◽  
Liquid State ◽  
Single Phase ◽  
Heat Treating ◽  
High Permeability ◽  
Metallic Material ◽  
Nickel Iron ◽  
Rapid Quench ◽  
Chemical Corporation

Abstract METGLAS Alloy 2826 (Fe40Ni40P14B6) is a ferromagnetic, high permeability, nickel-iron metallic glass which, when appropriately annealed, yields a material similar to the higher nickel containing permalloys in magnetic properties. Alloy 2826 is a single phase, opaque metallic material with a glass-like structure obtained by a very rapid quench from the liquid state. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on forming and heat treating. Filing Code: Ni-235. Producer or source: Allied Chemical Corporation.

Electron transfer and half-reactivity in nitrogenase

2011 ◽  
Vol 39 (1) ◽  
pp. 201-206 ◽  
Author(s):  
Thomas A. Clarke ◽  
Shirley Fairhurst ◽  
David J. Lowe ◽  
Nicholas J. Watmough ◽  
Robert R. Eady
Keyword(s):  
Electron Transfer ◽  
Protein Molecule ◽  
Stopped Flow ◽  
Protein Binding Sites ◽  
Molybdenum Iron Protein ◽  
Iron Protein ◽  
Mofe Protein ◽  
Fe Protein ◽  
Rapid Quench ◽  
Important Enzyme

Nitrogenase is a globally important enzyme that catalyses the reduction of atmospheric dinitrogen into ammonia and is thus an important part of the nitrogen cycle. The nitrogenase enzyme is composed of a catalytic molybdenum–iron protein (MoFe protein) and a protein containing an [Fe4–S4] cluster (Fe protein) that functions as a dedicated ATP-dependent reductase. The current understanding of electron transfer between these two proteins is based on stopped-flow spectrophotometry, which has allowed the rates of complex formation and electron transfer to be accurately determined. Surprisingly, a total of four Fe protein molecules are required to saturate one MoFe protein molecule, despite there being only two well-characterized Fe-protein-binding sites. This has led to the conclusion that the purified Fe protein is only half-active with respect to electron transfer to the MoFe protein. Studies on the electron transfer between both proteins using rapid-quench EPR confirmed that, during pre-steady-state electron transfer, the Fe protein only becomes half-oxidized. However, stopped-flow spectrophotometry on MoFe protein that had only one active site occupied was saturated by approximately three Fe protein equivalents. These results imply that the Fe protein has a second interaction during the initial stages of mixing that is not involved in electron transfer.

Charge State of Copper-Silicide Precipitates in Silicon and its Application to the Understanding of Copper Precipitation Kinetics

1998 ◽  
Vol 510 ◽  
Author(s):  
A.A. Istratov ◽  
O.F. Vyvenko ◽  
C. Flink ◽  
T. Heiser ◽  
H. Hieslmair ◽  
...  
Keyword(s):  
Charge State ◽  
Copper Ions ◽  
Deep Level ◽  
Precipitation Kinetics ◽  
Precipitation Behavior ◽  
Copper Silicide ◽  
Copper Precipitation ◽  
Type Silicon ◽  
Rapid Quench ◽  
P Type

AbstractDeep level spectra obtained on n-type silicon samples after copper diffusion and rapid quench give evidence of a positive charge state of the precipitates in p-type silicon. Non-exponential precipitation behavior of interstitial Cu is demonstrated and explained. The possibility of Coulomb interaction between copper ions and copper precipitates is suggested and its influence on Cu precipitation kinetics is disCussed.

Facile variation of reagent concentrations in rapid quench enzymology

2003 ◽  
Vol 312 (1) ◽  
pp. 80-83
Author(s):  
Jungsan Sohn ◽  
Johannes Rudolph
Keyword(s):  
Rapid Quench

Defect Induced Amortization in Silicon: A Tight Binding Molecular Dynamics Simulation

1993 ◽  
Vol 321 ◽  
Author(s):  
D. Maric ◽  
L. Colombo
Keyword(s):  
Molecular Dynamics ◽  
Electronic Properties ◽  
Structural Properties ◽  
Crystalline Silicon ◽  
Ion Beam ◽  
Tight Binding ◽  
Dynamics Simulation ◽  
Rapid Quench ◽  
Amorphous Network ◽  
Different Temperatures

ABSTRACTWe present an investigation on the amorphization process of crystalline silicon induced by ion beam bombardment by simulating the insertion of self-interstitials at different temperatures. The simulation is carried out by tight-binding molecular dynamics which allows for a detailed characterization of the chemical bonding and electronic properties of the irradiated samples. The irradiation process consists of two steps: (i) insertion of defects at a constant rate; (ii) annealing of the sample and observation of its structural properties. Thanks to the large size of the simulation cell (up to 276 atoms) we can characterize the amorphous network both on the short-range and Medium-range length scale. Electronic properties are investigated as well and their evolution is monitored during the insertion process. Finally, we present a thorough comparison of the structural properties of the irradiated sample with amorphous silicon as obtained by rapid quench from the Melt.

scholarly journals The mechanism of Klebsiella pneumoniae nitrogenase action. Pre-steady-state kinetics of H2 formation

1984 ◽  
Vol 224 (3) ◽  
pp. 877-886 ◽  
Author(s):  
D J Lowe ◽  
R N Thorneley
Keyword(s):  
Steady State ◽  
Klebsiella Pneumoniae ◽  
Necessary Condition ◽  
H2 Evolution ◽  
Mofe Protein ◽  
Fe Protein ◽  
Steady State Kinetics ◽  
Rapid Quench ◽  
Steady State Kinetic ◽  
H2 Formation

A comprehensive model for the mechanism of nitrogenase action is used to simulate pre-steady-state kinetic data for H2 evolution in the presence and in the absence of N2, obtained by using a rapid-quench technique with nitrogenase from Klebsiella pneumoniae. These simulations use independently determined rate constants that define the model in terms of the following partial reactions: component protein association and dissociation, electron transfer from Fe protein to MoFe protein coupled to the hydrolysis of MgATP, reduction of oxidized Fe protein by Na2S2O4, reversible N2 binding by H2 displacement and H2 evolution. Two rate-limiting dissociations of oxidized Fe protein from reduced MoFe protein precede H2 evolution, which occurs from the free MoFe protein. Thus Fe protein suppresses H2 evolution by binding to the MoFe protein. This is a necessary condition for efficient N2 binding to reduced MoFe protein.

scholarly journals Preparation of Electron Probe Microanalyzer Standards using a Rapid Quench Method

1966 ◽  
Vol 10 ◽  
pp. 431-446
Author(s):  
J. I. Goldstein ◽  
F. J. Majeske ◽  
H. Yakowitz
Keyword(s):  
Electron Probe ◽  
Microprobe Analysis ◽  
Test Cases ◽  
Electron Probe Microanalyzer ◽  
Cooling Method ◽  
Analytical Results ◽  
Rapid Quench ◽  
Quench Method

AbstractStandards for microprobe analysis can be made to serve two purposes: (a) proposed correction models can be tested with them, and (b) analysis can be performed more accurately in the system which includes the standard. Few microprobe standards presently are available because they must be homogeneous on the micron scale and their composition must be known accurately. A modified Duwez splat cooling method is described which enables the investigator to prepare suitable standards in most cases. The apparatus which is relatively simple and inexpensive is described in detail. The systems Au-Si and Al-Mg were chosen as test cases. Suitable standards were prepared at different concentrations in each system. The analytical results for all compositions in Al-Mg are presented and discussed.

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