Development and Application of Different Non-thermal Plasma Reactors for the Removal of Perfluorosurfactants in Water: A Comparative Study

Plasma Chemistry and Plasma Processing - The degradation of perfluorosurfactants (PFS), particularly of PFOS, has been studied in dielectric barrier discharge (DBD) and nano-pulse corona discharge...     

Volume integrals for low-energy p+208Pb optical potentials

Real and imaginary volume integrals for p+²⁰⁸Pb scattering are determined from sub-Coulomb cross section and analyzing power data. Additional consideration of neutron data yields the real symmetry potential. The results are compared with different theoretical approaches.     

Pearl chain formation of nanoparticles in microelectrode gaps by dielectrophoresis

The integration of molecular structures into microscopic electrode arrays is achieved by dielectrophoresis of gold nanoparticles in electrode gaps. Using microelectrodes realized by photolithography, we demonstrate here the generation of pearl chain arrangements of nanoparticles in structures accessible for standard technologies. To preserve the individual particle structures in the final nanowire arrangement, various strategies were employed. An electrical characterization of the pearl chains yielded an Ohmic behavior. The effect of increased current on these structures is studied at the ultramicroscopic level.     

The strange case of the “oscillating” catalysts

The field of stereoselective propene polymerization has been dramatically innovated by the discovery of homogeneous metallocene-based catalysts with well-defined and tunable molecular structure. Of all, “oscillating” metallocenes are probably the most ingenious and challenging example of catalyst design. Their catalytic species were built to “flip-flop” between a chiral and an achiral conformation, at a rate intermediate between those of monomer insertion and chain transfer. The result of this molecular switching would be a polypropylene with an isotactic/atactic stereoblock structure, performing as a thermoplastic elastomer. This essay discusses how the real polymerization mechanism differs from what the catalyst inventors had in mind, but also how - through fortunate circumstances -their optimism has been rewarded.     

Polarization transfer observables in π-d elastic scattering

Polarization transfer measurements in π⁺ elastic scattering have been performed at two incident pion energies, one below and one at the Δ(3, 3)-resonance. Using a vector polarized deuteron target four polarization transfer observables are determined. The results are compared to predictions from Faddeev calculations.     

Crystal and Molecular Structures of Modified Progestagens (I). 17α-Cyanomethyl-17β-hydroxy-estr-4-en-3-one,C20H27NO2

17α-Cyanomethyl-17β-hydroxy-estr-4-en-3-one is the first member in a series of progestagens investigated systematically by X-ray structure analyses. It crystallizes in the orthorhombic space group P 2₁2₁2₁ with cell parameters α = 8.887(6), b = 11.814(7), and c = 16.263(2) A. The structure was solved by MULTAN-82 and refined to R = 0.045 for 1453 observed reflections. The steroid ring A has an 1β-sofa conformation, the rings B and C adopt chair forms, ring D is intermediate between 13β,14α-half chair and 13β-envelope. All rings are trans-fused. In the present structure, O H… N hydrogen bonds link the molecules into chains parallel to α.     

The Molecular and Crystal Structure of 1Ref, 3trans-bis (4-chlorophenyl)-2cis-nitro-5-oxo-perhydropyrazolo [1,2-a]pyrazol

The structure of the title compound has been determined by means of an X-ray analysis. This product has been obtained by a 1,3-dipolar cycloaddition according to the concerted [π⁴S⁺π²S]-mechanism. The substance crystallizes in the monoclinic space group C 2/c with 8 molecules in the unit cell of dimensions a = 23.587; b = 11.789; c = 12.932 Å; β = 95.47°. The molecular structure determined by X-ray analysis agrees with the results of the chemical investigations. The final R-value is 0.081.