Group analysis and renormgroup symmetries

An original regular approach to constructing special type symmetries for boundary value problems, namely renormgroup symmetries, is presented. Different methods of calculating these symmetries, based on modern group analysis are described. Application of the approach to boundary value problems is demonstrated with the help of a simple mathematical model.Comment: 17 pages, RevTeX LATeX file, to appear in Journal of Mathematical Physic

Calculation of thermal parameters of SiGe microbolometers

The thermal parameters of a SiGe microbolometer were calculated using numerical modeling. The calculated thermal conduction and thermal response time are in good agreement with the values found experimentally and range between 2x10$^-7$ and 7x10$^-8$ W/K and 1.5 and 4.5 ms, respectively. High sensitivity of microbolometer is achieved due to optimization of the thermal response time and thermal conduction by fitting the geometry of supporting heat-removing legs or by selection of a suitable material providing boundary thermal resistance higher than 8x10$^-3$ cm$^2$K/W at the SiGe interface.Comment: 11 pages, 6 figure

The neutron-proton charge-exchange amplitudes measured in the dp -> ppn reaction

The unpolarised differential cross section and the two deuteron tensor analysing powers A_{xx} and A_{yy} of the pol{d}p -> (pp)n charge-exchange reaction have been measured with the ANKE spectrometer at the COSY storage ring. Using deuteron beams with energies 1.2, 1.6, 1.8, and 2.27 GeV, data were obtained for small momentum transfers to a (pp) system with low excitation energy. The results at the three lower energies are consistent with impulse approximation predictions based upon the current knowledge of the neutron-proton amplitudes. However, at 2.27GeV, where these amplitudes are far more uncertain, agreement requires a reduction in the overall double-spin-flip contribution, with an especially significant effect in the longitudinal direction. These conclusions are supported by measurements of the deuteron-proton spin-correlation parameters C_{x,x} and C_{y,y} that were carried out in the pol{d}pol{p} -> (pp)n reaction at 1.2 and 2.27GeV. The values obtained for the proton analysing power also suggest the need for a radical re-evaluation of the neutron-proton elastic scattering amplitudes at the higher energy. It is therefore clear that such measurements can provide a valuable addition to the neutron-proton database in the charge-exchange region.Comment: 13 pages with 13 figure

The Fabrication of Bioresorbable Implants for Bone Defects Replacement Using Computer Tomogram and 3D Printing

The present work demonstrates the possibility of production of personalized implants from bioresorbable polymers designed for replacement of bone defects. The stages of creating a personalized implant are described, which include the obtaining of 3D model from a computer tomogram, development of the model with respect to shape of bone fitment bore using Autodesk Meshmixer software, and 3D printing process from bioresorbable polymers. The results of bioresorbable polymer scaffolds implantation in pre-clinical tests on laboratory animals are shown. The biological properties of new bioresorbable polymers based on poly(lactic acid) were studied during their subcutaneous, intramuscular, bone and intraosseous implantation in laboratory animals. In all cases, there was a lack of a fibrous capsule formation around the bioresorbable polymer over time. Also, during the performed study, conclusions were made on osteogenesis intensity depending on the initial state of bone tissue

First measurements of spin correlations in the np -> d pi^0 reaction

The transverse spin correlations Axx and Ayy in the np-> d pi^0 reaction have been measured for the first time in quasi-free kinematics at the COSY-ANKE facility using a polarised deuteron beam incident on a polarised hydrogen cell target. The results obtained for neutron energies close to 353 MeV and 600 MeV are in good agreement with the partial wave analysis of data on the isospin-related pp-> d pi^+ reaction, though the present results cover also the small-angle region, which was largely absent from these data

The Fabrication of Bioresorbable Implants for Bone Defects Replacement Using Computer Tomogram and 3D Printing

The present work demonstrates the possibility of production of personalized implants from bioresorbable polymers designed for replacement of bone defects. The stages of creating a personalized implant are described, which include the obtaining of 3D model from a computer tomogram, development of the model with respect to shape of bone fitment bore using Autodesk Meshmixer software, and 3D printing process from bioresorbable polymers. The results of bioresorbable polymer scaffolds implantation in pre-clinical tests on laboratory animals are shown. The biological properties of new bioresorbable polymers based on poly(lactic acid) were studied during their subcutaneous, intramuscular, bone and intraosseous implantation in laboratory animals. In all cases, there was a lack of a fibrous capsule formation around the bioresorbable polymer over time. Also, during the performed study, conclusions were made on osteogenesis intensity depending on the initial state of bone tissue

Spin tune mapping as a novel tool to probe the spin dynamics in storage rings

Precision experiments, such as the search for electric dipole moments of charged particles using storage rings, demand for an understanding of the spin dynamics with unprecedented accuracy. The ultimate aim is to measure the electric dipole moments with a sensitivity up to 15 orders in magnitude better than the magnetic dipole moment of the stored particles. This formidable task requires an understanding of the background to the signal of the electric dipole from rotations of the spins in the spurious magnetic fields of a storage ring. One of the observables, especially sensitive to the imperfection magnetic fields in the ring is the angular orientation of stable spin axis. Up to now, the stable spin axis has never been determined experimentally, and in addition, the JEDI collaboration for the first time succeeded to quantify the background signals that stem from false rotations of the magnetic dipole moments in the horizontal and longitudinal imperfection magnetic fields of the storage ring. To this end, we developed a new method based on the spin tune response of a machine to artificially applied longitudinal magnetic fields. This novel technique, called \textit{spin tune mapping}, emerges as a very powerful tool to probe the spin dynamics in storage rings. The technique was experimentally tested in 2014 at the cooler synchrotron COSY, and for the first time, the angular orientation of the stable spin axis at two different locations in the ring has been determined to an unprecedented accuracy of better than $2.8\mu$rad.Comment: 32 pages, 15 figures, 7 table