Integral method of analysis for chemical reaction in a nonisothermal finite cylindrical catalyst pellet-II. Robin problem

1987 ◽  
Vol 42 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Suryanarayana Mukkavilli ◽  
Lawrence L. Tavlarides ◽  
Charles V. Wittmann
Keyword(s):  
Chemical Reaction ◽  
Integral Method ◽  
Robin Problem ◽  
Catalyst Pellet

scholarly journals Adsorption with chemical reaction in porous catalyst pellets under alternate concentration fields. Uniform temperature case

2016 ◽  
Vol 37 (4) ◽  
pp. 473-484
Author(s):  
Katarzyna Bizon ◽  
Bolesław Tabiś
Keyword(s):  
Chemical Reaction ◽  
Reaction Diffusion ◽  
Freundlich Isotherm ◽  
Entire Volume ◽  
Porous Catalyst ◽  
Linear Isotherm ◽  
Catalyst Pellet ◽  
Catalyst Pellets ◽  
The Impact ◽  
Sorption Phenomenon

Abstract The work concerns the dynamic behaviour of a porous, isothermal catalyst pellet in which a simultaneous chemical reaction, diffusion and adsorption take place. The impact of the reactant adsorption onto the pellet dynamics was evaluated. A linear isotherm and a non-linear Freundlich isotherm were considered. Responses of the pellet to sinusoidal variations of the reactant concentration in a bulk gas were examined. It was demonstrated that the dynamics of the pellet is significantly affected both by accounting for the adsorption and by the frequency of the bulk concentration variations. The sorption phenomenon causes damping of the concentration oscillations inside the pellet and damping of its effectiveness factor oscillations. Depending on the frequency of the concentration oscillations in the bulk, the remarkable oscillations can involve an entire volume of the pellet or its portion in the vicinity of the external surface.

Directional observation on lipid of male nectary of Lindera megaphylla hemsl. by the rapid embedding method with polyethylene glycol (PEG)

1990 ◽  
Vol 48 (3) ◽  
pp. 718-719
Author(s):  
Dai Dalin ◽  
Guo Jianmin
Keyword(s):  
Electron Microscope ◽  
Polyethylene Glycol ◽  
Chemical Reaction ◽  
Traditional Method ◽  
Osmium Tetroxide ◽  
Unsaturated Lipid ◽  
Embedding Method ◽  
Long Period ◽  
New Methods

Lipid cytochemistry has not yet advanced far at the EM level. A major problem has been the loss of lipid during dehydration and embedding. Although the adoption of glutaraldehyde and osmium tetroxide accelerate the chemical reaction of lipid and osmium tetroxide can react on the double bouds of unsaturated lipid to from the osmium black, osmium tetroxide can be reduced in saturated lipid and subsequently some of unsaturated lipid are lost during dehydration. In order to reduce the loss of lipid by traditional method, some researchers adopted a few new methods, such as the change of embedding procedure and the adoption of new embedding media, to solve the problem. In a sense, these new methods are effective. They, however, usually require a long period of preparation. In this paper, we do research on the fiora nectary strucure of lauraceae by the rapid-embedding method wwith PEG under electron microscope and attempt to find a better method to solve the problem mentioned above.

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