Oscillator experiments

MARE [32-38], Neutrino oscillation experiments have proved that neutrinos are massive particles, but cannot determine their absolute mass scale. Therefore, the neutrino mass is still an open question in elementary particle physics. An international collaboration is growing around the project of microcalorimeter arrays for a rhenium experiment (MARE) for directly measuring the neutrino mass with a sensitivity of about 0.2eV/c1 2 4. 

In the last decade, neutrino experiments have demonstrated that neutrinos are massive particles which may oscillate among three autostates. Such experiments [77-82] have evidenced the mass difference between the autostates, but not the neutrino mass scale value. The only way to determine the neutrino mass is the knowledge of the shape of the end point of energy spectrum in beta decays. In the hypothesis of the Majorana neutrino (neutrino coincides with antineutrino and its rest mass is different from zero), the measure of the decay half-life in the neutrinoless double-beta decay (DBD) would be necessary. A number of recent theoretical interpretations of neutrino oscillation experiments data imply that the effective Majorana mass of the electron neutrino (as measured in neutrinoless DBD) could be in the range 0.01 eV to the present bounds. 

Rheological measurements, 21 702-758 techniques in, 21 739-747 viscometers, 21 725-739 Rheological oscillation experiments,... 

The formulas obtained in section 2 can be used to estimate a sensitivity of oscillation experiments to different structures in the density profile. Apparently, an integration over the neutrino energy leads to averaging of oscillations and therefore to lost of the sensitivity. To estimate this effect we introduce the energy resolution function f(E, E) and perform averaging of the probability ... 

There are not a great number of studies on the viscoelastic behaviour of quasi-hard spheres. The studies of Mellema and coworkers13 shown in Figure 5.5 indicate the real and imaginary parts of the viscosity in a high-frequency oscillation experiment. Their data can be normalised to a characteristic time based on the diffusion coefficient given above. 

Since these processes are strongly dependent on temperature, it is appropriate to carry out torsion-oscillation experiments over a wide range of temperature, and to plot the values for the modulus and d against temperature (see Fig. 2.22). 

Schneider, F. W. (1985). Periodic perturbations of chemical oscillators experiments. Ann. Rev. Phys. Chem., 36, 347-78. 

Mixtures of chemically homogeneous methyl methacrylate— n-butyl acrylate copolymers appear homogeneous optically (clear) and in torsional oscillation experiments (one damping maximum) for A MM A 10-25 mole %. There is no... 

Oscillation experiments are performed in a polymer melt with cone-plate geometry, obtaining G and G" = 10 and 10 N/m, respectively, at CD = 10 rad/s. If in this region G and G" are linear functions of frequency, estimate the force per unit area tending to separate the cone and the upper plate when the lower plate rotates at an angular velocity O = 10 " rad/s. The cone-plate angle is or = 2°. 

If we take the same damped mass and spring system and, instead of driving the system with a motor, simply displace the mass and let it go, we find that it will oscillate with its natural resonance frequency and the amplitude of the oscillation will decay in time. The decay will be exponential with the amplitude proportional to exp(-t/T2p where the viscosity of the liquid will determine T. It is interesting to note that if you pluck the system, its oscillation and decay contains all the information of the system s behavior just as the frequency dependence of the amplitude in the driven simple harmonic oscillator experiment does. In the one case, the full width at half height of the resonance curve is 2/T, while in the other, the decay time constant is T. ... 

Forced-Oscillation Experiments. The dynamic moduli were measured as a function of frequency. At high strains (ca. 0.6), the Instron rheometer was used, whereas at lower strains (typically 0.16), the Bohlin VOR rheometer was used because of its greater sensitivity. Figure 6 shows the results obtained for the storage (G ) and loss (G") moduli for a 0.5-g dL" ... 

Forced-oscillation experiments indicated the presence of a relatively sharp relaxation process that appeared to show little dependence on polymer... 

Harmonic and transient relaxation experiments for dodecyl dimethyl phosphine oxide solutions were performed with the elastic ring method by Loglio [240]. This methods allows oscillation experiments in the frequency range from about 0.5 to 0.001 Hz and is suitable for comparatively slow relaxing systems. Slow oscillation experiments can be performed much easier now with the pendent drop apparatus [186]. Both techniques are also able to perform transient relaxation experiments. The two types of experiments have a characteristic frequency defined in the same way by Eq. (4.110). 

Example 14.2 Comment on the physical significance of the quantities measured in dynamic mechanical (oscillating) experiments. 

Derived from an analysis of neutrino-oscillation experiments. 

An oscillation experiment consists of submitting a fluid to a sinusoidal strain or stress. Mathematically, a sinusoidal strain can be written as... 

The change in interfacial tension during a sinusoidal surface area change for a sunflower oil drop in a protein solution at a eomparatively low oscillation frequency is shown in Fig. 18. Due to flie time required for image acquisition in the ADSA experiments faster oscillations are not possible wifliout the use of VCR (with a frame frequency of 25 Hz one can perform oscillation experiments at a maximum frequency of 1 Hz). 

Emulsion properties and stability can be measured by rheological studies and dielectric spectroscopy. Rheological studies include forced oscillation experi ments. The formation of stable emulsions is marked by a sharp increase in the elastic modulus. Water con tent is not a good indicator of emulsion characteristics other than that low water contents (<50%) indicate that an emulsion has not been formed and that the product is entrained water-in-oil. Interfacial measure ments are useful for measuring the film strength of... 

The instrument shown schematically in Fig. 26 is suitable for slow oscillation experiments, as it was performed for the first time by Miller et al. in 1993. The frequency limit of the oscillations is given by the condition for the liquid meniscus shape, which has to be Laplacian. Under too fast deformations this condition is not fulfilled and hence the method does not provide reliable results. To reach higher frequencies of oscillation, the above mentioned oscillating drop or bubble experiments are suitable, because the shape of the menisci is spherical due to the small diameter. The instrument of Fig. 26 can be designed such that a pressure sensor and piezo translator are built in and the video system serves as optical control and determines the drop/bubble diameter accurately. 

In Fig. 35 an oscillation experiment with a Triton X-100 solution is shown with a 400 s oscillation period. This oscillation can be quantitatively interpreted by a Fourier analysis, as it is implemented in most of the profile analysis tensiometer software. Another way of data... 

The Raman medium is taken as consisting of N harmonic oscillators per unit volume, which are independent of each other. Because of the combined action of the incident laser wave and the Stokes wave, the oscillators experience a driving force F that depends on the total field amplitude E... 

Fig. 5 Experimental layout for electrowetting-induced droplet shapemode oscillation experiments showing electrowetting chip, highspeed camera, and driving signal-generation system...

For H18 we observe an increase of the network stability (yield point 10 Pa) in the oscillation experiment and a decrease of the relaxation time to less than 3 s in the presence of Palatal P4. Both effects can be put down to the fact that the polarity of the mixture is enhanced by the resin oligomers, which increases the interaction energy with respect to PDMS-PDMS entanglement and the phase separation between the grafted PDMS layer and the surrounding medium occurs faster. 

When hydrophilic fumed silica N20 is dispersed in a vinyl ester Adac S90/styrene mixture the oscillation experiment reveals that the fumed silica is not able to build up a percolating network, as indicated by the lack of a yield point (Fig. 5b). This is also supported by the observation that the relaxation time of the N20/Atlac 590/styrene system is markedly longer than the time frame of the viscosity relaxation experiment of 500 s (Fig. 5a). 

Thus the steady state oscillator experiment determines Fn si - -Sn) as a function of only one transform variable at a time. It is easily seen that the result (16) corresponds to the assumption... 

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