Eine Methode der quantitativen Bestimmung der Aepfels?ure

Ohne Zusammenfassung     

Zum gerichtlich-chemischen Nachweis der Alkaloide und narkotischen Bitterstoffe

Ohne Zusammenfassung     

Qualitative und quantitative Spektralanalyse

Ohne Zusammenfassung     

Maghemite nanoparticles with very high AC-losses for application in RF-magnetic hyperthermia

Maghemite nanoparticles covalently coated with polyethylene glycol are investigated with respect to different loss processes in magnetic AC-fields. Transmission electron microscopy reveals a narrow size distribution which may be well approximated by a normal distribution (mean diameter 15.3 nm and distribution width 4.9 nm). Aqueous ferrofluids were characterised by DC-magnetometry, by measuring susceptibility spectra for a frequency range 20 Hz to 1 MHz and by calorimetric measurements of specific loss power (SLP) at 330 and 410 kHz for field amplitudes up to 11.7 kA/m. Extremely high values of SLP in the order of 600 W/g result for 400 kHz and 11 kA/m. In addition to liquid ferrofluids measurements were performed with suspensions in gel in order to elucidate the role of Brownian relaxation. The measured susceptibility spectra may be well reproduced by a model using a superposition of Néel and Brown loss processes under consideration of the observed narrow normal size distribution. In this way the observed very high specific heating power may be well understood. Results are discussed with respect to further optimisation of SLP for medical as well as technical RF-heating applications.     

Photoproduction of neutral pions on deuterium at forward angles in the first resonance region

At the 500 MeV electron synchrotron in Bonn differential cross sections of the reaction γ + d → π⁰ + d were measured in forward pion c.m. angles and photon energies between 340 and 420 MeV.     

Measurement of the target asymmetry for the reaction γp↑ → π+n at photon energies between 0.7 and 2.2 GeV and a pion CM-angle of 65°

At the Bonn 2.5.GeV electron synchrotron the target asymmetry for the photoproduction of positive pions has been measured. Data were taken at photon energies between 0.7 and 2.2 GeV and a pion CM-angle of 65°.     

Synthesis of Necatorone

The mutagenic fungal alkaloid necatorone has been obtained by a six-step synthesis starting from 2-(3,4-dimethoxyphenyl) ethylamine and 2-nitro-5-methoxybenzoyl chloride.