Felix Becker

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The reductive biotransformation of mercuric ions to elemental mercury was studied by applying a model system with a genetically engineered Pseudomonas putida strain in a lab scale three-phase fluidized bed (TPFB). The aim was to demonstrate the suitability of the TPFB to demercurize effluent streams containing up to 10 mg Hg2+ dm(-3). The TPFB is used,(More)
Non-selective effects, like genetic drift, are an important factor in modern conceptions of evolution, and have been extensively studied for constant population sizes (Kimura, 1955; Otto and Whitlock, 1997). Here, we consider non-selective evolution in the case of growing populations that are of small size and have varying trait compositions (e.g. after a(More)
Specific ion effects ranking in the Hofmeister sequence are ubiquitous in biochemical, industrial, and atmospheric processes. In this experimental study specific ion effects inexplicable by the classical DLVO theory have been investigated at curved water-metal interfaces of gold nanoparticles synthesized by a laser ablation process in liquid in the absence(More)
The molar mass distribution (MMD) of synthetic polymers is frequently analyzed by size exclusion chromatography (SEC) coupled to multi angle light scattering (MALS) detection. For ultrahigh molar mass (UHM) or branched polymers this method is not sufficient, because shear degradation and abnormal elution effects falsify the calculated molar mass(More)
Overview Due to the high-current operation at UNILAC nonintercepting beam diagnostics is mandatory. In October 2008 a Beam Induced Fluorescent (BIF) monitor for transverse profile determination was set up in the UNILAC section US1. It serves as a prototype for the installation at 7 locations at UNILAC and the transfer channel to SIS. The comissioning and(More)
W hen approaching the gas/liquid critical point, earth gravity (1 g) induces growing density inhomogeneities in a fluid. This is due to the critical divergence of the compressibility. A microgravity (~tg) environment, e.g. in a Spacelab is considered to be a prerequisite for maintaining a homogeneous density distribution in a fluid in thermal equilibrium(More)
Scintillating screens are a direct but destructive method to observe transverse ion beam profiles. Depending on ion species, beam current and energy, scintillators can be selected from a large variety of materials and were subject of detailed investigations at UNILAC [1]. In this article we report on a pilot study for FAIR in which scintillating properties(More)
Scintillation screens are widely used since decades for qualitative beam profile measurement. Via scintillation screens one can obtain a direct and entire image of the transversal beam profile. Moreover, these screens are an essential part of a pepper-pot emittance system [1, 2] for which the imaged beam width σ is important. Therefore, we investigated the(More)