Kinetics of partly diffusion controlled reactions. III. Competition between physical and chemical kinetics. Experimental results

1979 ◽  
Vol 37 (1) ◽  
pp. 119-131 ◽  
Author(s):  
J.C. Andre ◽  
M. Bouchy ◽  
W.R. Ware
2014 ◽  
Vol 20 (1) ◽  
pp. 71-86 ◽  
Author(s):  
Vesna Nadjalin ◽  
Zika Lepojevic ◽  
Mihailo Ristic ◽  
Jelena Vladic ◽  
Branislava Nikolovski ◽  
...  

In this study essential oil content was determined in lavender flowers and leaves by hydrodistillation. Physical and chemical characteristics of the isolated oils were determined. By using CO2 in supercritical state the extraction of lavender flowers was performed with a selected solvent flow under isothermal and isobaric conditions. By the usage of gas chromatography in combination with mass spectrometry (GC/MS) and gas chromatography with flame ionisation detector (GC/FID) the qualitative and quantitative analysis of the obtained essential oil and supercritical extracts (SFE) was carried out. Also, the analysis of individual SFE extracts obtained during different extraction times was performed. It turned out that the main components of the analysed samples were linalool, linalool acetate, lavandulol, caryophyllene oxide, lavandulyl acetate, terpinen-4-ol and others. Two proposed models were used for modelling the extraction system lavender flower - supercritical CO2 on the basis of experimental results obtained by examining the extraction kinetics of this system. The applied models fitted well with the experimental results.


Author(s):  
H. C. Grigg ◽  
M. H. Syed

Two simple models for the rate of heat release in diesel engines are described. The factors taken into account in the models are rate of entrainment of air into the fuel sprays, the rate of turbulent mixing of fuel and air within the spray, and the chemical kinetics of burning. The models differ in their treatment of the rate of air entrainment. Comparisons are made with experimental results for a diesel engine running at two speeds and a variety of turbocharging ratios. The overall agreement with experiment in respect of shape of rate of heat release diagram is good, with the exception of the naturally aspirated cases where the rate of air entrainment is too low.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1686
Author(s):  
Andrey Galukhin ◽  
Roman Nosov ◽  
Ilya Nikolaev ◽  
Elena Melnikova ◽  
Daut Islamov ◽  
...  

A new rigid tricyanate ester consisting of seven conjugated aromatic units is synthesized, and its structure is confirmed by X-ray analysis. This ester undergoes thermally stimulated polymerization in a liquid state. Conventional and temperature-modulated differential scanning calorimetry techniques are employed to study the polymerization kinetics. A transition of polymerization from a kinetic- to a diffusion-controlled regime is detected. Kinetic analysis is performed by combining isoconversional and model-based computations. It demonstrates that polymerization in the kinetically controlled regime of the present monomer can be described as a quasi-single-step, auto-catalytic, process. The diffusion contribution is parameterized by the Fournier model. Kinetic analysis is complemented by characterization of thermal properties of the corresponding polymerization product by means of thermogravimetric and thermomechanical analyses. Overall, the obtained experimental results are consistent with our hypothesis about the relation between the rigidity and functionality of the cyanate ester monomer, on the one hand, and its reactivity and glass transition temperature of the corresponding polymer, on the other hand.


Soil Science ◽  
1993 ◽  
Vol 155 (1) ◽  
pp. 53-60 ◽  
Author(s):  
SADAO SHOJI ◽  
MASAMI NANZYO ◽  
YASUHITO SHIRATO ◽  
TOYOAKI ITO

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