COMPARISON OF ANGLES AND THE CORRESPONDING MOMENTS IN KNEE AND HIP DURING RESTRICTED AND UNRESTRICTED SQUATS

The aim of this study is the comparison of angles and the corresponding moments in knee and hip during squatting. The five subjects performed restricted and unrestricted squats. The experimental set-up consisted of a motion capture system and two force plates. The loading conditions were 0, ¼ and ½ BW. The moments and the force were calculated using inverse dynamics. Overall, the maximal moments were observed in the knee during unrestricted squats and in the hip during restricted squats. Comparing the moments at a knee angle of 60º, the loading conditions have a larger influence than the type of execution. The moment in the knee is 10.4%, respectively 11.2% lower with ¼ and ½ body weight during restricted squats. In the hip, the moment is 15.5 %, respectively 14 % higher for the same conditions. The angle of the hip remains rather constant. This most likely implies a higher load to the lower back. Hence, the exercise instruction should be adapted to the aims and the training condition of the athlete

The beta-spectrum of 35S^{35}S and search for the admixture of heavy neutrinos

The $\eta$-spectrum of $^{35}$S has been measured with highstatistical precision. A total of $2.2 \times 10^{10}$ eventshave been accumulated with a signal to background ratio of $10^{3}$ or better. A systematic search for neutrino mixing has been performedfor assumed neutrino masses up to 105 keV. In the mass range10 to 90 keV, an upper limit around $10^{-3}$ or less wasset for the mixing probability

A β\beta-spectrometer for searching effects of finite neutrino masses

A detailed description of a Tret'yakov-type magnetic$\beta$--spectrometer with electrostatic acceleration is presented.The instrument is being used for high precision measurements of the$\beta$--spectra of various isotopes and to search for neutrinomixing and heavy neutrinos with masses up to $100 \,$keV$/c^2$.The relative momentum resolution, obtained with an extendedsource ($3 \times 2 \,$cm$^2$) and a large silicon stripdetector, is $\delta p/p = 6.9 \times 10^{-4}$ (FWHM).The width of the energy band, which can simultaneously be measuredwith this resolution, is typically 50 times larger than thecorresponding width of the energy resolution.The detector delivers pulse-height and one-dimensional positioninformation. The read-out electronics provides a seperate channelfor each detector strip, allowing measurements to be madewith high count rate and small dead-time losses.The detection of scattered electrons was minimized by thearrangement of baffles and by the use of materials with smallatomic number. Experimentally, scattering in the spectrometerwas investigated by accelerating photoelectrons up to $60 \,$keV energy. A system for measuring the corresponding high voltageis described.Extensive Monte Carlo simulations of scattering in the spectrometerhave been performed. Good agreement with the experimental datawas obtained and there was no need to adjust any scatteringcross section to the particular experimental situation. Weconclude that calculated scattering probabilities can reliablybe used in the analysis of experimental $\beta$--spectra,which is important as otherwise scattering would constitute amajor uncertainty

Search for heavy neutrinos in the β\beta-spectrum of 63Ni^{63}Ni

The $\beta$-spectrum of $^{63}$Ni has been measured with highprecision in order to search for effects of heavy neutrinos.For assumed neutrino masses in the range 4 to $30 \,$keV,upper limits of $10^{-3}$ or less are reported for themixing probability