Synthesis of Benzylidene and Azo Containing Polymers for Photophisical Application

In the present work, the polymers built with the use of the free radical polymerization of methacrylic monomers incorporating an azobenzene side-group and monomers with benzylidene fragments have been synthesized. The polymerization was carried out in DMF with AIBN as initiator. The products of polymerization were characterized by HNMR. The results of investigations of photochemical and optical activities of the corresponding polymers are presented

Non-Gaussian signatures of Tachyacoustic Cosmology

I investigate non-Gaussian signatures in the context of tachyacoustic cosmology, that is, a noninflationary model with superluminal speed of sound. I calculate the full non-Gaussian amplitude $\mathcal{A}$, its size $f_{\rm NL}$, and corresponding shapes for a red-tilted spectrum of primordial scalar perturbations. Specifically, for cuscuton-like models I show that $f_{\rm NL}\sim {\cal O}(1)$, and the shape of its non-Gaussian amplitude peaks for both equilateral and local configurations, the latter being dominant. These results, albeit similar, are quantitatively distinct from the corresponding ones obtained by Magueijo {\it{et. al}} in the context of superluminal bimetric models.Comment: Some comments and references added. Matches the version published in JCA

Quaternionic factorization of the Schroedinger operator and its applications to some first order systems of mathematical physics

We consider the following first order systems of mathematical physics. 1.The Dirac equation with scalar potential. 2.The Dirac equation with electric potential. 3.The Dirac equation with pseudoscalar potential. 4.The system describing non-linear force free magnetic fields or Beltrami fields with nonconstant proportionality factor. 5.The Maxwell equations for slowly changing media. 6.The static Maxwell system. We show that all this variety of first order systems reduces to a single quaternionic equation the analysis of which in its turn reduces to the solution of a Schroedinger equation with biquaternionic potential. In some important situations the biquaternionic potential can be diagonalized and converted into scalar potentials

Effects of Nonlinear Dispersion Relations on Non-Gaussianities

We investigate the effect of non-linear dispersion relations on the bispectrum. In particular, we study the case were the modified relations do not violate the WKB condition at early times, focusing on a particular example which is exactly solvable: the Jacobson-Corley dispersion relation with quartic correction with positive coefficient to the squared linear relation. We find that the corrections to the standard result for the bispectrum are suppressed by a factor $\frac{H^2}{p_c^2}$ where $p_c$ is the scale where the modification to the dispersion relation becomes relevant. The modification is {\it mildly} configuration-dependent and equilateral configurations are more suppressed with respect to the local ones, by a factor of one percent. There is no configuration leading to enhancements. We then analyze the results in the framework of particle creation using the approximate gluing method of Brandenberger and Martin, which relates more directly to the modeling of the trans-Planckian physics via modifications of the vacuum at a certain cutoff scale. We show that the gluing method overestimates the leading order correction to the spectrum and bispectrum by one and two orders, respectively, in $\frac{H}{p_c}$. We discuss the various approximation and conclude that for dispersion relations not violating WKB at early times the particle creation is small and does not lead to enhanced contributions to the bispectrum. We also show that in many cases enhancements do not occur when modeling the trans-Planckian physics via modifications of the vacuum at a certain cutoff scale. Most notably they are only of order O(1) when the Bogolyubov coefficients accounting for particle creation are determined by the Wronskian condition and the minimization of the uncertainty between the field and its conjugate momentum.Comment: v1: 11 pages, 2 figures; v2: references update

Внутрішньовенна інфузія лідокаїну для знеболення під час лапароскопічних холецистектомій

Лапароскопічна холецистектомія є методом вибору для хірургічного лікування гострого холециститу, який дозволяє скоротити перебування пацієнтів у стаціонарі, зменшити витрати коштів та прискорити відновлення працездатності. Але поряд із перевагами постає перешкода – через малий термін госпіталізації після втручання стає неможливим використання інвазивних методів знеболення. Саме тому біль є головною причиною відтермінування виписки пацієнта, що спонукає до пошуків способу підвищення ефективності періопераційного знеболення. Системне введення лідокаїну інтраопераційно може покращити знеболення пацієнтів під час лапароскопічних холецистектомій (ЛХЕ) та зменшити опіат-асоційовані побічні ефекти. Метою дослідження було визначити ефективність та безпечність внутрішньовенної інфузії лідокаїну для знеболення під час ЛХЕ. Проспективне контрольоване дослідження проводилось на клінічній базі кафедри хірургії, анестезіології та інтенсивної терапії Інституту післядипломної освіти НМУ імені О. О. Богомольця. У дослідження було включено 60 дорослих пацієнтів з гострим та хронічним холециститом, яким планувалась ЛХЕ, та рандомізовано до груп дослідження – група Л (лідокаїну) та група К (контрольна). Інтраопераційна внутрішньовенна інфузія лідокаїну під час ЛХЕ зменшувала середню інтенсивність болю у спокої та при рухах, кількість пацієнтів з помірним та сильним болем, кількість знеболень “за вимогою”. Застосування інтраопераційної інфузії лідокаїну дозволяло достовірно зменшити споживання анестетиків та анальгетиків інтраопераційно та у ранньому післяопераційному періоді, та відповідно зменшити частоту опіат-асоційованих побічних ефектів, прискорити відновлення функцій кишечника після ЛХЕ та зменшити інтраопераційну інцидентність артеріальної гіпертензії

Phonon-Coupled Electron Tunneling in Two and Three-Dimensional Tunneling Configurations

We treat a tunneling electron coupled to acoustical phonons through a realistic electron phonon interaction: deformation potential and piezoelectric, in two or three-dimensional tunneling configurations. Making use of slowness of the phonon system compared to electron tunneling, and using a Green function method for imaginary time, we are able to calculate the change in the transition probability due to the coupling to phonons. It is shown using standard renormalization procedure that, contrary to the one-dimensional case, second order perturbation theory is sufficient in order to treat the deformation potential coupling, which leads to a small correction to the transmission coefficient prefactor. In the case of piezoelectric coupling, which is found to be closely related to the piezoelectric polaron problem, vertex corrections need to be considered. Summing leading logarithmic terms, we show that the piezoelectric coupling leads to a significant change of the transmission coefficient.Comment: 17 pages, 4 figure

Role of beam polarization in the determination of WWγWW\gamma and WWZWWZ couplings from e+e−→W+W−e^+e^-\to W^+W^-

We evaluate the constraints on anomalous trilinear gauge-boson couplings that can be obtained from the study of electron-positron annihilation into $W$ pairs at a facility with either the electron beam longitudinally polarized or both electron and positron beams transversely polarized. The energy ranges considered in the analysis are the ones relevant to the next-linear collider and to LEP~200. We discuss the possibilities of a model independent analysis of the general $CP$ conserving anomalous effective Lagrangian, as well as its restriction to some specific models with reduced number of independent couplings. The combination of observables with initial and final state polarizations allows to separately constrain the different couplings and to improve the corresponding numerical bounds.Comment: 24 pages, LaTeX, 9 figures (available on request from the authors

Discrete breathers in classical spin lattices

Discrete breathers (nonlinear localised modes) have been shown to exist in various nonlinear Hamiltonian lattice systems. In the present paper we study the dynamics of classical spins interacting via Heisenberg exchange on spatial $d$-dimensional lattices (with and without the presence of single-ion anisotropy). We show that discrete breathers exist for cases when the continuum theory does not allow for their presence (easy-axis ferromagnets with anisotropic exchange and easy-plane ferromagnets). We prove the existence of localised excitations using the implicit function theorem and obtain necessary conditions for their existence. The most interesting case is the easy-plane one which yields excitations with locally tilted magnetisation. There is no continuum analogue for such a solution and there exists an energy threshold for it, which we have estimated analytically. We support our analytical results with numerical high-precision computations, including also a stability analysis for the excitations.Comment: 15 pages, 12 figure

Can residuals of the Solar system foreground explain low multipole anomalies of the CMB ?

The low multipole anomalies of the Cosmic Microwave Background has received much attention during the last few years. It is still not ascertained whether these anomalies are indeed primordial or the result of systematics or foregrounds. An example of a foreground, which could generate some non-Gaussian and statistically anisotropic features at low multipole range, is the very symmetric Kuiper Belt in the outer solar system. In this paper, expanding upon the methods presented by Maris et al. (2011), we investigate the contributions from the Kuiper Belt objects (KBO) to the WMAP ILC 7 map, whereby we can minimize the contrast in power between even and odd multipoles in the CMB, discussed discussed by Kim & Naselsky (2010). We submit our KBO de-correlated CMB signal to several tests, to analyze its validity, and find that incorporation of the KBO emission can decrease the quadrupole-octupole alignment and parity asymmetry problems, provided that the KBO signals has a non-cosmological dipole modulation, associated with the statistical anisotropy of the ILC 7 map. Additionally, we show that the amplitude of the dipole modulation, within a 2 sigma interval, is in agreement with the corresponding amplitudes, discussed by Lew (2008).Comment: 24 pages, 9 figures, 5 tables. Matches version in JCA