A thermo-reversible silicone elastomer with remotely controlled self-healing

Soft thermoplastic elastomers with increased durability and reliability are in high demand for a broad spectrum of applications. Silicone elastomers are soft and durable, but they are not thermoplastic in nature, and under extreme conditions such as high voltage or large deformations, reliability may also suffer. Thus, as a solution to these shortcomings, which are typical of silicone elastomers, it is natural to propose a thermo-reversible, self-healing, and recyclable silicone-based elastomer. Stimuli-responsivity is imparted to the silicone polymer by incorporating supramolecular 2-ureido-4[1H]-pyrimidone (UPy) self-assembling motifs via free radical polymerisation. Self-healing of the novel elastomer may be triggered by both direct and indirect heating, the latter by means of incorporating Fe(3)O(4) particles into the elastomer and subsequent exposure to an alternating magnetic field. As a consequence of temperature responsiveness and high thermal stability, the elastomer is proven recyclable, by withstanding multiple reprocessing procedures with no substantial effects on the resulting properties. The synergy of these valuable characteristics makes this novel material a smart candidate for innumerable applications where soft and reliable elastomers are sought

Collective oscillations of a stored deuteron beam close to the quantum limit

We investigated coherent betatron oscillations of a deuteron beam in the storage ring COSY, excited by a detuned radio-frequency Wien filter. These beam oscillations were detected by conventional beam position monitors, read out with lock-in amplifiers. The response of the stored beam to the detuned Wien filter was modelled using the ring lattice and time-dependent 3D field maps of the radio-frequency Wien filter. The influence of uncertain system parameters related to manufacturing tolerances and electronics was investigated using the polynomial chaos expansion. With the currently available apparatus, we show that oscillation amplitudes down to \SI{1}{\micro \meter} can be detected. Future measurements of the electric dipole moment of protons will, however, require control of the relative position of counter-propagating beams in the sub-picometer range. Since the stored beam can be considered as a rarefied gas of uncorrelated particles, we moreover demonstrate that the amplitudes of the zero-point betatron oscillations of individual particles are within a factor of 10 of the Heisenberg uncertainty limit. As a consequence of this, we conclude that quantum mechanics does not preclude the control of the beam centroids to sub-picometer accuracy. The smallest Lorentz force exerted on a single particle that we have been able to determine is \SI{10}{aN}.Comment: 38 pages, 16 figure

Pilot bunch and co-magnetometry of polarized particles stored in a ring

In polarization experiments at storage rings, one of the challenges is to maintain the spin-resonance condition of a radio-frequency spin rotator with the spin-precessions of the orbiting particles. Time-dependent variations of the magnetic fields of ring elements lead to unwanted variations of the spin precession frequency. We report here on a solution to this problem by shielding (or masking) one of the bunches stored in the ring from the high-frequency fields of the spin rotator, so that the masked pilot bunch acts as a co-magnetometer for the other signal bunch, tracking fluctuations in the ring on a time scale of about one second. While the new method was developed primarily for searches of electric dipole moments of charged particles, it may have far-reaching implications for future spin physics facilities, such as the EIC and NICA.Comment: 5 pages, 3 figures + references + supplemental material (6 pages, 2 figures, 6 tables + references

Spin decoherence and off-resonance behavior of radiofrequency-driven spin rotations in storage rings

Radiofrequency-driven resonant spin rotators are routinely used as standard instruments in polarization experiments in particle and nuclear physics. Maintaining the continuous exact parametric spin-resonance condition of the equality of the spin rotator and the spin precession frequency during operation constitutes one of the challenges. We present a detailed analytic description of the impact of detuning the exact spin resonance on the vertical and the in-plane precessing components of the polarization. An important part of the formalism presented here is the consideration of experimentally relevant spin-decoherence effects. We discuss applications of the developed formalism to the interpretation of the experimental data on the novel pilot bunch approach to control the spin-resonance condition during the operation of the radiofrequency-driven Wien filter that is used as a spin rotator in the first direct deuteron electric dipole moment measurement at COSY. We emphasize the potential importance of the hitherto unexplored phase of the envelope of the horizontal polarization as an indicator of the stability of the radiofrequency-driven spin rotations in storage rings. The work presented here serves as a satellite publication to the work published concurrently on the proof of principle experiment about the so-called pilot bunch approach that was developed to provide co-magnetometry for the deuteron electric dipole moment experiment at COSY.Comment: 31 pages, 10 figures, 5 table

On the Prediction of Floods Caused by Rainfall in the Area of Action of the Meteorological Radar “Meteor 735CDP10”

Meteorological radar “METEOR 735CDP10” manufactured by “SELEX” (Germany) has been used since 2015 in the operational work of the anti-hail service of Georgia (indication of radar parameters for active exposure to hail dangerous and hail clouds - maximum reflectivity of clouds, height of maximum reflectivity, maximum cloud height, the size of hailstones in the cloud, etc.). Work is carried out in the Kakheti region of Georgia. The working radius of the radar in this case is 100-120 km and covers the entire territory of Kakheti. Season of the anti-hail works continues from April to October. The radar also allows you to determine the intensity of liquid precipitation, and when fixing in its computer program the coordinates of the area where floods often occur during rainfall, it is possibility forecasting these floods. Moreover, out the season of anti-hail works, the radius of the radar can be increased to 200 km and almost cover almost the entire territory of Eastern Georgia. The paper provides a map of points with recurring floods during rainfall in Eastern Georgia and examples of comparing radar data on precipitation intensity with flood data at these points. The accumulation of this information will allow creating an algorithm for flood forecasting in Eastern Georgia based on the results of radar monitoring of the precipitation intensity

Storm Wind in Tbilisi and Rustavi Cities on 21 September 2019. Analysis of Data of Radar, Aerological and Ground-Based Measurements

Results of analysis of the data of radar, aerological and ground-based measurements of the storm wind in Tbilisi and Rustavi cities, which was observed on September 21, 2019, are represented. In particular, it is obtained that the data of radar observation about wind speed at the level 2.0 km above Tbilisi are in the satisfactory agreement with the data of ground-based measurements. Data of radiosonde for the same height show the substantially decreased values of wind spee