Mechanisms of hydrides’ nucleation and the effect of hydrogen pressure induced driving force on de-/hydrogenation kinetics of Mg-based nanocrystalline alloys

2021 ◽  
Author(s):  
Fenghai Guo ◽  
Tiebang Zhang ◽  
Limin Shi ◽  
Yu Chen ◽  
Lin Song
Keyword(s):  
Driving Force ◽  
Hydrogen Pressure ◽  
Nanocrystalline Alloys ◽  
Hydrogenation Kinetics ◽  
Kinetics Of

Hydrogenation Kinetics of N-Ethylcarbaozle as a Heteroaromatic Liquid Organic Hydrogen Carrier

2014 ◽  
Vol 953-954 ◽  
pp. 981-984 ◽  
Author(s):  
Ming Yang ◽  
Yuan Dong ◽  
Han Song Cheng
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Hydrogen Pressure ◽  
Reaction Rate ◽  
Hydrogenation Reaction ◽  
First Order ◽  
First Order Kinetics ◽  
Hydrogenation Kinetics ◽  
Hydrogen Carrier ◽  
Kinetics Of

The catalytic hydrogenation kinetics of N-ethylcarbazole over 5 wt% Ru/Al2O3 was investigated at various temperatures. The results shows that the hydrogenation reaction was exothermic and high temperature is unfavorable for the reaction rate. Fully hydrogenation was achieved within 1 hour under the best reaction temperature of 170 °C. The kinetics of N-ethylcarbazole follows the first-order kinetics in terms of the reactant concentration but independent of hydrogen pressure, which was maintained as a constant in the reaction process. The apparent activation energy of N-ethylcarbazole hydrogenation reaction at 150-180 °C was found to be 71.2 kJ/mol.

Dynamic Transformation of Austenite at Temperatures above the Ae3

2018 ◽  
Vol 941 ◽  
pp. 633-638
Author(s):  
John Joseph Jonas ◽  
Clodualdo Aranas Jr. ◽  
Samuel F. Rodrigues
Keyword(s):  
Electron Microscopy ◽  
Driving Force ◽  
Energy Difference ◽  
Accelerated Cooling ◽  
Free Energy Difference ◽  
Dynamic Transformation ◽  
Plate Rolling ◽  
Temperature Transformation ◽  
Mn Steel ◽  
Kinetics Of

Under loading above the Ae3 temperature, austenite transforms displacively into Widmanstätten ferrite. Here the driving force for transformation is the net softening during the phase change while the obstacle consists of the free energy difference between austenite and ferrite as well as the work of shear accommodation and dilatation during the transformation. Once the driving force is higher than the obstacle, phase transformation occurs. This phenomenon was explored here by means of the optical and electron microscopy of a C-Mn steel deformed above their transformation temperatures. Strain-temperature-transformation (STT) curves are presented that accurately quantify the amount of dynamically formed ferrite; the kinetics of retransformation are also specified in the form of appropriate TTRT diagrams. This technique can be used to improve the models for transformation on accelerated cooling in strip and plate rolling.

The effect of hydrogen pressure on the kinetics of the HDDR-process of bulk Nd-Fe-B-type alloys

1994 ◽  
Vol 30 (2) ◽  
pp. 642-644 ◽  
Author(s):  
O. Gutfleisch ◽  
C. Short ◽  
M. Verdier ◽  
I.R. Harris
Keyword(s):  
Hydrogen Pressure ◽  
Kinetics Of

scholarly journals THE KINETICS OF EXOSMOSIS OF WATER FROM LIVING CELLS

1927 ◽  
Vol 10 (5) ◽  
pp. 659-664 ◽  
Author(s):  
Morton McCutcheon ◽  
Baldwin Lucke
Keyword(s):  
Osmotic Pressure ◽  
Salt Concentration ◽  
Driving Force ◽  
Temperature Characteristic ◽  
Living Cells ◽  
Velocity Constant ◽  
Osmotic Equilibrium ◽  
Kinetics Of

1. The rate of exosmosis of water was studied in unfertilized Arbacia eggs, in order to bring out possible differences between the kinetics of exosmosis and endosmosis. 2. Exosmosis, like endosmosis, is found to follow the equation See PDF for Equation, in which a is the total volume of water that will leave the cell before osmotic equilibrium is attained, x is the volume that has already left the cell at time t, and k is the velocity constant. 3. The velocity constants of the two processes are equal, provided the salt concentration of the medium is the same. 4. The temperature characteristic of exosmosis, as of endomosis, is high. 5. It is concluded that the kinetics of exosmosis and endosmosis of water in these cells are identical, the only difference in the processes being in the direction of the driving force of osmotic pressure.

Hydrogenation kinetics of toluene on Pt/ZSM-22

2002 ◽  
Vol 90 (1-2) ◽  
pp. 117-129 ◽  
Author(s):  
Joris W. Thybaut ◽  
Mark Saeys ◽  
Guy B. Marin
Keyword(s):  
Hydrogenation Kinetics ◽  
Kinetics Of

Enhanced dehydrogenation/hydrogenation kinetics of the Mg(NH2)2–2LiH system with NaOH additive

2011 ◽  
Vol 36 (3) ◽  
pp. 2137-2144 ◽  
Author(s):  
Chu Liang ◽  
Yongfeng Liu ◽  
Zhijun Wei ◽  
Ying Jiang ◽  
Fan Wu ◽  
...  
Keyword(s):  
Hydrogenation Kinetics ◽  
Kinetics Of

Syneresis in Silica Gel

1988 ◽  
Vol 121 ◽  
Author(s):  
George W. Scherer
Keyword(s):  
Fluid Flow ◽  
Sample Size ◽  
Silica Gel ◽  
Chemical Reactions ◽  
Driving Force ◽  
Viscoelastic Behavior ◽  
Accurate Representation ◽  
Flow Through ◽  
Kinetics Of ◽  
Gel Network

ABSTRACTThe driving force for syneresis is generally attributed to the same chemical reactions that produce gelation, but it has also been proposed that shrinkage could be driven by interracial energy. The latter possibility is explored and discounted. The kinetics of syneresis depend on the driving force, the mobility of the gel network, and the rate of fluid flow through the contracting gel. A model that allows for viscoelastic behavior of the gel and fluid flow according to Darcy's law is shown to provide a quantitatively accurate representation of the shape of the shrinkage curves and the dependence of the shrinkage rate on sample size.

Kinetics of ο-Chloronitrobenzene Hydrogenation on Palladium/Carbon Catalyst

2011 ◽  
Vol 239-242 ◽  
pp. 161-167
Author(s):  
Xiao Zhen Wang ◽  
Yi Feng Zhu ◽  
Xiao Nian Li
Keyword(s):  
High Selectivity ◽  
Total Yield ◽  
Hydrogenation Reaction ◽  
Commercial Application ◽  
Reaction Conditions ◽  
Solvent Free Conditions ◽  
Hydrogenation Kinetics ◽  
Favorable Reaction ◽  
Kinetics Of ◽  
Very High

A 2 wt % Pd/C catalyst has been prepared by chemical impregnation and used to catalyze the hydrogenation of o-chloronitrobenzene (o-CNB) to o-chloroaniline (o-CAN) in solvent-free conditions. The effects of reaction temperature, H2 pressure, and stirring intensity on the hydrogenation kinetics have been investigated. The hydrogenation reaction showed very high selectivity with dehalogenation side products as low as 0.3% of total yield. The favorable reaction conditions were found to be temperature T = 383 K, stirring speed = 900 rpm, and feeding ratio CNB/catalyst = 200/1 (m/m). The recycled Pd/C still retained more than 98% of its original selectivity after 12 repeat used, indicating the catalyst had strong potentials for commercial application at industrial scale.

Hydrogenation Kinetics of N -Ethylindole on a Supported Ru Catalyst

2018 ◽  
Vol 6 (3) ◽  
pp. 558-562 ◽  
Author(s):  
Yuan Dong ◽  
Ming Yang ◽  
Ting Zhu ◽  
Xuedi Chen ◽  
Chenguang Li ◽  
...  
Keyword(s):  
Ru Catalyst ◽  
Hydrogenation Kinetics ◽  
Kinetics Of
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