scholarly journals Numerical methods for reaction kinetics parameters: identification of low-temperature propane conversion in the presence of methane

2017 ◽  
Vol 201 ◽  
pp. 612-616 ◽  
Author(s):  
L.F. Akhmadullina ◽  
L.V. Enikeeva ◽  
I.M. Gubaydullin
Keyword(s):  
Numerical Methods ◽  
Low Temperature ◽  
Reaction Kinetics ◽  
Parameters Identification ◽  
Propane Conversion ◽  
Kinetics Parameters

Kinetics of catalytic conversion of methanol at higher pressures

1980 ◽  
Vol 45 (12) ◽  
pp. 3402-3407 ◽  
Author(s):  
Jaroslav Bartoň ◽  
Vladimír Pour
Keyword(s):  
Low Temperature ◽  
Reaction Kinetics ◽  
Water Vapour ◽  
Kinetic Data ◽  
Catalytic Conversion ◽  
The Given ◽  
Kinetics Of

The course of the conversion of methanol with water vapour was followed on a low-temperature Cu-Zn-Cr-Al catalyst at pressures of 0.2 and 0.6 MPa. The kinetic data were evaluated together with those obtained at 0.1 MPa and the following equation for the reaction kinetics at the given conditions was derived: r = [p(CH3OH)p(H2O)]0.5[p(H2)]-1.3.

The Present and the Future Perspectives of Biological Network Inference

2011 ◽  
pp. 118-140 ◽  
Author(s):  
Paola Lecca ◽  
Alida Palmisano
Keyword(s):  
Reaction Kinetics ◽  
Network Structure ◽  
Network Inference ◽  
Biological Network ◽  
Reaction Pathway ◽  
Model Identification ◽  
Chemical Species ◽  
Kinetics Parameters ◽  
Common Opinion ◽  
Genomic Biology

Biological network inference is based on a series of studies and computational approaches to the deduction of the connectivity of chemical species, the reaction pathway, and the reaction kinetics of complex reaction systems from experimental measurements. Inference for network structure and reaction kinetics parameters governing the dynamics of a biological system is currently an active area of research. In the era of post-genomic biology, it is a common opinion among scientists that living systems (cells, tissues, organs and organisms) can be understood in terms of their network structure as well as in term of the evolution in time of this network structure. In this chapter, the authors make a survey of the recent methodologies proposed for the structure inference and for the parameter estimation of a system of interacting biological entities. Furthermore, they present the recent works of the authors about model identification and calibration.

Low-temperature vulcanizable chloroprene rubber–bromobutyl rubber blend for encapsulation of undersea sensors: Nonconventional cure systems and reaction kinetics

2019 ◽  
Vol 52 (4) ◽  
pp. 322-336
Author(s):  
PN Mohanadas ◽  
T Mukundan ◽  
T Santhanakrishnan
Keyword(s):  
Zinc Oxide ◽  
High Temperature ◽  
Low Temperature ◽  
Reaction Kinetics ◽  
Weight Ratio ◽  
Temperature Sensitive ◽  
Encapsulation Process ◽  
Red Lead ◽  
Chloroprene Rubber ◽  
Cure Temperature

Blends of chloroprene rubber (CR) and bromobutyl rubber (BIIR) are used in making the undersea sensors watertight by a process of encapsulation. The encapsulation process is conventionally done at high temperature approximately 150°C and above using high-temperature vulcanization (HTV). However, the new class of acoustic sensors like polyvinilidenefluride (PVDF) and thin film PZT are highly temperature sensitive and fragile in nature and hence they require low-temperature vulcanization (LTV) process to avoid damages and protect their full functionalities. However, conventional cure systems are not adoptable in LTV process and hence there is a need for the search of alternate cure systems. Not much work has been reported in this area. This article reports a nonconventional cure system vulcanizable with LTV and the associated reaction kinetics for a commonly used CR–BIIR blend for encapsulation of undersea sensors. Formulations have been attempted with cure systems based on red lead (Pb3O4) and zinc oxide (ZnO) for CR–BIIR blend in 80:20 weight ratio, instead of zinc oxide, magnesium oxide, and ethylene thiourea system, which are conventionally used in HTV. The cure parameters at low temperature between 70°C and 120°C and the activation energy for cure reactions ( E a) were estimated using MDR 2000 rheometer. Essential prerequisites like water resistance, electrical resistivity, and physicomechanical properties for sensor application are qualitatively analyzed for the blend cured at 90°C. The results reveal that the proposed nonconventional cure systems are able to bring down the cure temperature of CR–BIIR blend to 90°C from 150°C enabling the suitability of the materials for undersea sensor encapsulation.

scholarly journals A self-adjusting platinum surface for acetone hydrogenation

2020 ◽  
Vol 117 (7) ◽  
pp. 3446-3450 ◽  
Author(s):  
Benginur Demir ◽  
Thomas Kropp ◽  
Keishla R. Rivera-Dones ◽  
Elise B. Gilcher ◽  
George W. Huber ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Density Functional ◽  
Surface Coverage ◽  
Binding Energies ◽  
Microkinetic Modeling ◽  
Reaction Conditions ◽  
Platinum Surface ◽  
Kinetics Parameters ◽  
Supported Platinum Catalysts ◽  
Wide Range

We show that platinum displays a self-adjusting surface that is active for the hydrogenation of acetone over a wide range of reaction conditions. Reaction kinetics measurements under steady-state and transient conditions at temperatures near 350 K, electronic structure calculations employing density-functional theory, and microkinetic modeling were employed to study this behavior over supported platinum catalysts. The importance of surface coverage effects was highlighted by evaluating the transient response of isopropanol formation following either removal of the reactant ketone from the feed, or its substitution with a similarly structured species. The extent to which adsorbed intermediates that lead to the formation of isopropanol were removed from the catalytic surface was observed to be higher following ketone substitution in comparison to its removal, indicating that surface species leading to isopropanol become more strongly adsorbed on the surface as the coverage decreases during the desorption experiment. This phenomenon occurs as a result of adsorbate–adsorbate repulsive interactions on the catalyst surface which adjust with respect to the reaction conditions. Reaction kinetics parameters obtained experimentally were in agreement with those predicted by microkinetic modeling when the binding energies, activation energies, and entropies of adsorbed species and transition states were expressed as a function of surface coverage of the most abundant surface intermediate (MASI, C3H6OH*). It is important that these effects of surface coverage be incorporated dynamically in the microkinetic model (e.g., using the Bragg–Williams approximation) to describe the experimental data over a wide range of acetone partial pressures.

Steady-state reaction kinetics of CO oxidation catalyzed by uni-sized Pt30 clusters directly bound to Si surface

2016 ◽  
Vol 6 (18) ◽  
pp. 6910-6915 ◽  
Author(s):  
H. Yasumatsu ◽  
N. Fukui
Keyword(s):  
Steady State ◽  
Low Temperature ◽  
Co Oxidation ◽  
Reaction Kinetics ◽  
Co Poisoning ◽  
Si Substrate ◽  
Catalytic Co Oxidation ◽  
Kinetics Of

Catalytic CO oxidation driven by uni-sized Pt30 bound to a Si substrate, at the interface of which electrons are accumulated. The low-temperature and anti-CO-poisoning performance has been evidenced with continuous and simultaneous supply of CO and O2.

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