Matrix polymerization and polyelectrolyte complex formation

We developed a model of the formation of symplexes by photoinitiated matrix polymerization. Symplexes are insoluble in water and all known solvents. They result from contrarily charged polyelectrolytes. In our model a polyelectrolyte is matrix and binder simultaneously. At the matrix a contrarily charged monomer is polymerized radically to the second polyelectrolyte. Different mechanisms are discussed for the matrix polymerization. As polymerizable monomers acrylic compounds with terminal tertiary amino group were used. Modified styrene/maleic acid copolymers served as polyanion. The influence of the composition of the components in this layers on the polymerization rate was investigated. The sensitivity of the developed photo-material is compared with other photo-polymerization systems and the conventional photographic materials basing on silver halogenides. A high resolution and an easy fixation result.     

Projecting systems of linear inequalities with binary variables

We investigate methods for projecting out 0–1 variables from a system of linear inequalities. After reviewing some special cases like monotone polyhedra and the satisfiability problem, we examine why Fourier elimination cannot be applied to the general case. Finally, we give a procedure based on disjunctive programming for solving the general case. We also discuss a simpler procedure applicable only under certain conditions.     

Cross‐Polarization Electron‐Nuclear Double Resonance Spectroscopy

Magnetic nuclei in the proximity of a paramagnetic center can be polarized through electron‐nuclear cross‐polarization and detected in electron‐nuclear double resonance (ENDOR) spectroscopy. This principle is demonstrated in a single‐crystal model sample as well as on a protein, the β2 subunit of E.coli ribonucleotide reductase (RNR), which contains an essential tyrosyl radical. ENDOR is a fundamental technique to detect magnetic nuclei coupled to paramagnetic centers. It is widely employed in biological and materials sciences. Despite its utility, its sensitivity in real samples is about one to two orders of magnitude lower than conventional electron paramagnetic resonance, thus restricting its application potential. Herein, we report the performance of a recently introduced concept to polarize nuclear spins and detect their ENDOR spectrum, which is based on electron‐nuclear cross polarization (eNCP). A single‐crystal study permits us to disentangle eNCP conditions and CP‐ENDOR intensities, providing the experimental foundation in agreement with the theoretical prediction. The CP‐ENDOR performance on a real protein sample is best demonstrated with the spectra of the essential tyrosyl radical in the β2 subunit of E.coli RNR.     

Über nitriertems-Phenyl-dinaphthopyrane

Ohne Zusammenfassung2. Mitteilung, Monatsh. f. Ch.49 (1928).     

Improvements in the selection of real components forming a substitute mixture for petroleum fractions

Complex mixtures, particularly petroleum fractions, usually need to be suitably modeled before providing the simulation and other types of chemical engineering calculations. The most convenient way is to describe the original mixture by a substitute mixture. The formerly published approach based on the employment of substitute mixtures of real components can be improved in order to get a closer match between the behavior of the original and substitute mixtures. In the first phase of the algorithm, a new concept of a band around the characterization curves brings wider possibilities for the selection of real components into the substitute mixture. The second phase, which is used to determine the composition of the substitute mixture, can be also improved by considering the global or bulk properties of the original mixture if available. Typically, some of the properties e.g. liquid density, molecular mass and PNA (Paraffinic/Naphthenic/Aromatic carbon) analysis can be measured and used to improve the adjustment of the composition. The improved algorithm is illustrated by an example.