scholarly journals Spatiotemporal reaction kinetics of an ultrafast photoreaction pathway visualized by time-resolved liquid x-ray diffraction

2006 ◽  
Vol 103 (25) ◽  
pp. 9410-9415 ◽  
Author(s):  
T. K. Kim ◽  
M. Lorenc ◽  
J. H. Lee ◽  
M. Lo Russo ◽  
J. Kim ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

Kinetics of Intercalation in Lamellar Hosts Using Time-Resolved X-Ray Diffraction

1998 ◽  
pp. 153-158
Author(s):  
Dermot O’Hare ◽  
John S. O. Evans ◽  
Stephen Price
Keyword(s):  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

Kinetics of Multi-Step Redox Processes by Time-Resolved In Situ X-ray Diffraction

2016 ◽  
Vol 88 (11) ◽  
pp. 1684-1692 ◽  
Author(s):  
Lukas C. Buelens ◽  
Vladimir V. Galvita ◽  
Hilde Poelman ◽  
Christophe Detavernier ◽  
Guy B. Marin
Keyword(s):  
Redox Processes ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

Kinetics of the lamellar-inverse hexagonal phase transition determined by time-resolved x-ray diffraction

Biochemistry ◽  
1992 ◽  
Vol 31 (4) ◽  
pp. 1081-1092 ◽  
Author(s):  
Mark W. Tate ◽  
Erramilli Shyamsunder ◽  
Sol M. Gruner ◽  
Kevin L. D'Amico
Keyword(s):  
Phase Transition ◽  
Hexagonal Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

Isothermal nucleation and growth kinetics of Pd/Ag alloy phase via in situ time-resolved high-temperature X-ray diffraction (HTXRD) analysis

2008 ◽  
Vol 316 (1-2) ◽  
pp. 97-111 ◽  
Author(s):  
M. Engin Ayturk ◽  
E.A. Payzant ◽  
S.A. Speakman ◽  
Y.H. Ma
Keyword(s):  
High Temperature ◽  
Growth Kinetics ◽  
Nucleation And Growth ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Kinetics Of

Influence of oxygen partial pressure on the kinetics of YBa2Cu3O7−x formation

1994 ◽  
Vol 9 (2) ◽  
pp. 275-285 ◽  
Author(s):  
V. Milonopoulou ◽  
K.M. Forster ◽  
J.P. Formica ◽  
J. Kulik ◽  
J.T. Richardson ◽  
...  
Keyword(s):  
X Ray Diffraction ◽  
Decomposition Products ◽  
Time Resolved ◽  
X Ray ◽  
Formation Kinetics ◽  
Dimensional Diffusion ◽  
Diffusion Controlled ◽  
Gas Atmosphere ◽  
Kinetics Of

The YBa2Cu3O7−x formation kinetics from a spray-roasted precursor powder containing Y2O3, BaCO3, and CuO was followed via in situ, time-resolved x-ray diffraction as a function of gas atmosphere and temperature. In inert atmospheres, BaCO3 and CuO form BaCu2O2 which subsequently reacts with Y2O3 to form YBa2Cu3O6. However, YBa2Cu3O6 decomposes at temperatures exceeding 725 °C with Y2BaCuO5 being one of the decomposition products. In oxidizing atmospheres, YBa2Cu3O7−x formation involves the BaCuO2. At high temperatures (800–840 °C), oxygen increases the yield of YBa2Cu3O6. A nuclei growth model assuming two-dimensional, diffusion-controlled growth with second-order nucleation rate fits the experimental data.

Reaction Kinetics of Acetone Peroxide Formation and Structure Investigations Using Raman Spectroscopy and X-Ray Diffraction

2009 ◽  
Vol 63 (1) ◽  
pp. 92-97 ◽  
Author(s):  
L. Jensen ◽  
P. M. Mortensen ◽  
R. Trane ◽  
P. Harris ◽  
R. W. Berg
Keyword(s):  
Raman Spectroscopy ◽  
Reaction Kinetics ◽  
X Ray Diffraction ◽  
Peroxide Formation ◽  
X Ray ◽  
Acetone Peroxide ◽  
Structure Investigations ◽  
Kinetics Of

Properties of Pure and Sulfided NiMoO4 and CoMoO4 Catalysts: Tpr, Xanes and Time-Resolved XRD Studdzs

1997 ◽  
Vol 497 ◽  
Author(s):  
S. Chaturvedi ◽  
J. A. Rodriguez ◽  
J. C. Hanson ◽  
A. Albornoz ◽  
J. L. Brito
Keyword(s):  
Electronic Properties ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
Direct Transformation ◽  
X Ray ◽  
Β Phase ◽  
Structural And Electronic Properties ◽  
X Ray Absorption ◽  
Kinetics Of ◽  
Cobalt And Nickel

ABSTRACTX-ray absorption near-edge spectroscopy (XANES) was used to characterize the structural and electronic properties of a series of cobalt- and nickel-molybdate catalysts (AMoO4.nH20, α-AMoO4, β-AMoO4; A= Co or Ni). The results of XANES indicate that the Co and Ni atoms are in octahedral sites in all these compounds, while the coordination of Mo varies from octahedral in the a-phases to tetrahedral in the β-phases and hydrate. Time-resolved x-ray diffraction shows a direct transformation of the hydrates into the β-AMoO4 compounds (following a kinetics of first order) at temperatures between 200 and 350 °C. This is facilitated by the similarities that the AMoO4.nH20 and β-AMoO4 compounds have in their structural and electronic properties. The molybdates react with H 2 at temperatures between 400 and 600 °C, forming gaseous water and oxides in which the oxidation state of Co and Ni remains +2 while that of Mo is reduced to +5 or +4. After exposing α-NiMoO4 and P-NiMoO4 to H2S, both metals get sulfided and a NiMoSx phase is formed. For the β phase of NiMoO4 the sulfidation of Mo is more extensive than for the a phase, making the former a better precursor for catalysts of hydrodesulfurization reactions.

In Situ Time-Resolved X-Ray Diffraction Investigation of the ω→ψ Transition in Al-Cu-Fe Quasicrystal-Forming Alloys

2007 ◽  
Vol 558-559 ◽  
pp. 943-947 ◽  
Author(s):  
E. Otterstein ◽  
R. Nicula ◽  
J. Bednarčík ◽  
M. Stir ◽  
E. Burkel
Keyword(s):  
Large Scale ◽  
Applied Pressure ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
In Situ Xrd ◽  
Kinetics Of

Quasicrystals are aperiodic long-range ordered solids with a high potential for many modern applications. Interest is nowadays paid to the development of economically viable large-scale synthesis procedures of quasicrystalline materials involving solid-state transformations. The kinetics of the high-temperature phase transition from the complex ω-phase to the icosahedral quasicrystalline (iQC) ψ-phase in AlCuFe nanopowders was here examined by in-situ time-resolved X-ray diffraction experiments using synchrotron radiation. In-situ XRD experiments will allow insight on the influence of uniaxial applied pressure on the kinetics of phase transitions leading to the formation of single-phase QC nanopowders and further contribute to the optimization of sintering procedures for nano-quasicrystalline AlCuFe alloy powders.

scholarly journals GLYCEROLYSIS USING KF/CAO-MGO CATALYST: OPTIMISATION AND REACTION KINETICS

2020 ◽  
Vol 82 (5) ◽  
Author(s):  
Luqman Buchori ◽  
Mohammad Djaeni ◽  
R. Ratnawati ◽  
Diah Susetyo Retnowati ◽  
H. Hadiyanto ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Gas Chromatography Mass Spectrometry ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Base Catalysts ◽  
Cooking Oil ◽  
Surface Method ◽  
Kinetics Of ◽  
Glycerolysis Reaction

Monoglycerides can be produced through glycerolysis using a heterogeneous catalyst. The purpose of this study is to analyse the optimum conditions for the production of monoglycerides from glycerol and cooking oil using KF/CaO-MgO base catalysts and to investigate the kinetics of the monoglyceride glycerolysis reaction. The response surface method (RSM) was used to determine the favourable conditions by varying the catalyst amount (X1) between 0.1, 0.2 and 0.3% (w/w); the reaction temperature (X2) between 210, 220 and 230°C and reaction time (X3) between 2, 3 and 4 hours. Gas chromatography-mass spectrometry (GC-MS) was used to determine the monoglycerides, while catalysts were characterised by X-ray diffraction (XRD) and the Brunauer-Emmett-Teller method (BET). The results showed that, among the three factors examined, temperature shows the most control over this glycerolysis reaction. The most favourable conditions are X1 = 0.19% (w/w), X2 = 208.37°C and X3 = 3.20 hours, which provide a monoglyceride yield of 41.58%. The constants for the reaction kinetics of the monoglyceride formation, k1 and k2 are 1.04189 and 0.88965 hour-1, respectively.

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