a two-dimensional cfd model of a planar solid oxide fuel cell (sofc) has been developed.this model can predict the performance of sofc at various operating and design conditions.the effect of knudsen diffusion is accounted in the porous electrode (backing) and reaction zonelayers. the mathematical model solves conservation of electrons and ions and conservation ofspecies. the model is formulate...

The astronomical gas-phase detection of simple species and small organic molecules in cold pre-stellar cores, with abundances as high as ~10-10 nH, contradicts the generally accepted idea that at 10 K, such species should be fully frozen out on grain surfaces. A physical or chemical mechanism that results in a net transfer from solid-state species into the gas-phase offers a possible explanatio...

 phenytoine derivatives were synthesized , via the  pinacol condensation  with the  reaction of 1,3- diphenyl- propane- 1,3- dione (benzyl) analogs with urea or thiourea in presence of slica gel and solid KOH as Solid phase catalyst  in the mortar / pestle at room temperatures. The reaction was completed at short reaction times (approximately 15min) and pure products were obtained with high yie...

Atmospheric particles adversely affect visibility, health, and climate, yet the kinetics and mechanisms of particle formation and growth are poorly understood. Multiphase reactions between amines and dicarboxylic acids (diacids) have been suggested to contribute. In this study, the reactions of n-butylamine (BA) with solid C3-C8 diacids were studied at 296 ± 1 K using a Knudsen cell interfaced ...

The heats of adsorption on weakly activated ^-aluminium oxide for a number of linear alkanes (from n-butane to n-nonane) and for 2.2.4-trimethylpentane have been determined by GSC and extrapolated to zero surface coverage. The dependance of the adsorption energy on the number of carbon atoms is discussed on the basis of the bidimensional gas model: it is shown that the interactions of the adsor...

The outline of this chapter is as follows: *.1 will show some application areas together with the number of types of reactors available for carrying out gas-solid catalyzed reactions. Section *.2 will focus on the kinetic models suitable for describing these reactions. Section *.3 will show how to set up the reactor models and will also show the mass transport interactions need to be modeled. T...

Ultrasound assisted phase-transfer catalyzed preparation of ethyl 2-(4-nitrophenoxy)acetate from the corresponding p-nitrophenol and ethyl 2-bromoacetate using the mild solid base, anhydrous potassium carbonate, under very mild conditions is reported. The solid-liquid reactions were performed in a batch reactor equipped with reflux condenser, and ultrasonic irradiations were introduced using an...

The alkaline thermal treatment of biomass has recently been proposed as a novel method for producing high purity H2 with suppressed COx formation under moderate reaction conditions (i.e., 523 K and ambient pressure). This technology has a great potential for sustainable bioenergy production because it can handle a wide range of feedstocks including biomass and biogenic wastes with high water co...

In physical adsorption the interaction of adsorbed molecules with solids is mainly due to induction forces acting between the surface electric field and permanent or induced dipoles in the adsorbate, and to L O N D O N dispersion forces, these prevailing, for example, in adsorption of apolar molecules In the last years it has been shown that the dielectric behaviour of the heterogeneous adsorbe...

silica-bonded n-propyltriethylene-tetramine (sbnptt) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4h-chromenes. chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oc under solvent-free conditions. the heterogeneous solid base showed much the same efficiency when u...