Excited states in 163,164Ho populated through incomplete-fusion reactions

High-spin states in ^163,164Ho were investigated by means of in-beam -ray spectroscopy techniques using the multidetector array GASP. Excited states in ^163,164Ho were populated predominantly through the incomplete-fusion mechanism in the ¹⁶⁰Gd (¹¹B reaction at a beam energy of 61 MeV. Known rotational bands in ¹⁶³ Ho have been extended to higher spins and a three-quasiparticle band has been observed in this nucleus. Rotational bands have been identified in ¹⁶⁴Ho and their configurations have been discussed. Empirical Gallagher-Moszkowski (GM) splitting energies were extracted from the and GM doublets. Alignments, band crossing frequencies, and electromagnetic properties have been analyzed in the framework of the cranking model.Received: 13 February 2004, Revised: 18 March 2004, Published online: 14 September 2004PACS: 21.10.Re Collective levels - 21.60.Ev Collective models - 23.20.Lv transitions and level energies - 27.70. + q      

Schl?sing's L?throhr

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Second-harmonic generation in a doubly resonant semiconductor microcavity

We demonstrate second-harmonic generation in a doubly resonant semiconductor microcavity. The monolithic cavity consists of an AlGaAs active medium sandwiched between two AlGaAs/AlAs dual-wavelength mirrors. The mirrors do not have any apparent periodicity because, unlike single- or dual-wavelength Bragg reflectors, they are engineered with dispersion taken into account. Quasi-phase matching is obtained by addition of the appropriate phases at reflection so as to compensate for the dephasing between the fundamental and the second-harmonic fields.     

Hybridized bands and parity splitting in the odd-odd nucleus220Ac

The high spin state structure of the nucleus²²⁰Ac was investigated by means of the²⁰⁹Bi(¹⁴C, 3n) reaction. In beamγ ray spectroscopy was carried out using the Château de Cristal multidetector array. Gamma ray multipolarities were established by extracting directional correlation ratios from the Ge—Ge coincidence data and by intensity balance considerations. The level scheme, established up to 18 ? above the lowest observed state, consists of three alternating parity bands. The data are interpreted in terms of the reflection asymmetric shapes of the nucleus. The analysis of the parity doublet candidates does not show the decrease of the parity splitting predicted for an odd-odd nucleus.     

Numerical vibration analysis on defect detection in revolving machines using two bearing models

Summary Monitoring by vibration measurement and analysis is largely used in the industry for detection of defects in revolving parts of machines. The determination of good sensor positions is one of the main research goals in the field of predictive maintenance. This paper proposes a numerical methodology based on the FEM and spectral analysis in order to find the optimum sensor positions. Bearings are key components in the vibration propagation from moving parts to immobile ones. Two existing nonlinear models of bearings are recalled and implemented in a FE code. The obtained tangent stiffness matrices of bearings are then put in the global system to-study the dynamic behaviour. The dynamic response of the whole system under defect excitations is used to determine the optimum sensor placements for the defect detection in the predictive maintenance.     

Ueber eine Reaction des Quecksilberchlorids

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