Hopf structures on ambiskew polynomial rings

We derive necessary and sufficient conditions for an ambiskew polynomial ring to have a Hopf algebra structure of a certain type. This construction generalizes many known Hopf algebras, for example U(sl₂), U_q(sl₂) and the enveloping algebra of the three-dimensional Heisenberg Lie algebra. In a torsion-free case we describe the finite-dimensional simple modules, in particular their dimensions, and prove a Clebsch-Gordan decomposition theorem for the tensor product of two simple modules. We construct a Casimir type operator and prove that any finite-dimensional weight module is semisimple.     

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.     

Novel highly soluble 3,3′-bicarbazolyl based polymers for optoelectronics

Novel family of highly soluble polymers containing 3.3′-bicarbazolyl moieties is reported. Utilizing simple and efficient chemical oxidation of carbazole and its derivatives by iron trichloride exclusively and quantitatively yields the bicarbazolyl dimmers with reactive oxirane groups. The polymers were prepared in polyaddition reaction of bicarbazolyl-containing diepoxydes with 4,4′-thiobisbenzenethiol, 2,5-dimercapto-1,3,4-thiadiazole, or 1,3-benzenedithiol in the presence of catalyst triethylamine. Obtained compounds were characterized using GPC, DSC, IR, UV, fluorescence and ¹H NMR spectroscopy. The hole drift mobility reaches 10⁻⁴ cm²/Vs at high electric fields. Such processable polymers with conjugated-nonconjugated repeating units in the main chain and good charge carrier mobility are quite promising for fabrication of optoelectronic devices.