Porous flow model for cellular foams

Relations for the permeability of a cellular foam structure are obtained using the equations of the theory of flow through porous media. It is shown that in calculating the flow through a foam using a polyhedral model gives values of the flow rate that are several times too low, and this error does not completely disappear with increase in the polyhedricity of the foam structure (with increase in multiplicity).Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 2, pp. 86–89, March–April, 1990.     

Intermolecular Pauson-Khand reactions on a galactose scaffold

An intermolecular Pauson-Khand reaction involving a carbohydrate scaffold having a pendant alkyne provides galactose derivatives with a cyclopentenone moiety in the C3-position in up to 85% yield.     

Carbon-carbon and carbon-heteroatom bond formation on solid phase using cationic iron carbonyl complexes

Iron-mediated methodology for the formation of carbon-carbon and carbon-heteroatom sp(3) bonds on solid phase has been developed. Treatment of a polymer-bound cationic iron cyclohexadienyl complex with carbon, oxygen, nitrogen, and phosphorus nucleophiles, followed by cleavage with amines and subsequent decomplexation, yielded 18 different cyclohexadienoic acid amides of high purity. [reaction: see text]     

A Film Model of Sound Propagation in Gas–Liquid Foams: 2. The Sound Absorption

The concepts of the sound energy dissipation in gas–liquid foams are described within the framework of the film model of sound propagation. The high absorption of sound in foams is explained by hydrodynamic losses in foam films. The experimental dependence of the absorption coefficient on the foam expansion is explained. The calculated expansion corresponding to the absorption maximum is close to the experimental value.     

Polyfluorinated heterocyclic compounds

The condensation of sodium acetoacetate ester with polyfluoroaromatic compounds proceeds according to a type of S-arylation with subsequent ring formation or deacetylation depending on the condition employed.For part III, see [5].     

Modular synthesis of ChiraClick ligands: a library of P-chirogenic phosphines

A library of novel and diverse P-chirogenic phosphine ligands containing a triazole moiety (ChiraClick ligands) were prepared in high yield in a modular fashion that allows for variation of both the phosphine and the triazole structure, as well as giving access to the two enantiomers of the ligand.     

Steady filtration through foam

The process of filtration of a liquid through a deformable porous medium with the structure of a gas-liquid foam is considered. A basis is provided for a model of fluid flow through foam. Expressions are obtained for the differential law of steady filtration and the integral laws of filtration through a vertical column of foam under the influence of body and surface forces.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 98–103, May–June, 1986.