An improved HPTLC method for the rapid identification and quantification of sulfonamides

Summary R_f values of twenty therapeutic sulfonamides have been estimated in seven solvent systems. Based on these data a simple identification scheme was developed demanding only three solvent systems for complete separation.Quantification of corresponding fluorescamine derivatives at nanogram level was performed by the use of an TLC-scanner configured online with a microcomputer. Mathematical treatment of standard curves using the computer program Curve Fitter are discussed. Validity and reproducibility of results are compared with data obtained by HPLC and show good correlation.     

Inertia and damping effects on the damage-dependent burst size distribution of fiber bundles

Distributions of simultaneous fiber failures—bursts—in loaded fiber bundles are studied considering inertia and damping. Resulting burst size distributions have universal properties: all approach the power law D_ΔΔ^−2.5 for larger burst sizes Δ. Momentary burst size distributions evolve with increasing damage and do not follow power laws but are still universal. Finally, it is briefly outlined how to use distribution progression to assess damage state.     

Intorno ad una classe notevole di cicli formati da quattro trasformazioni di Laplace nello spazio ordinario

Annali di Matematica Pura ed Applicata (1923 -) -