Thermalized polarization dynamics of a discrete optical-waveguide system with four-wave mixing

Statistical mechanics of two coupled vector fields is studied in the tight-binding model that describes propagation of polarized light in discrete waveguides in the presence of the four-wave mixing. The energy and power conservation laws enable the formulation of the equilibrium properties of the polarization state in terms of the Gibbs measure with positive temperature. The transition line T=∞ is established beyond which the discrete vector solitons are created. Also in the limit of the large nonlinearity an analytical expression for the distribution of Stokes parameters is obtained, which is found to be dependent only on the statistical properties of the initial polarization state and not on the strength of nonlinearity. The evolution of the system to the final equilibrium state is shown to pass through the intermediate stage when the energy exchange between the waveguides is still negligible. The distribution of the Stokes parameters in this regime has a complex multimodal structure strongly dependent on the nonlinear coupling coefficients and the initial conditions

Soliton transmission through disordered system

An exact formula for the transmission time in the disordered nonlinear soliton-bearing classical one-dimensional system is obtained

Modulation control and spectral shaping of optical fiber supercontinuum generation in the picosecond regime

Numerical simulations are used to study how fiber supercontinuum generation seeded by picosecond pulses can be actively controlled through the use of input pulse modulation. By carrying out multiple simulations in the presence of noise, we show how tailored supercontinuum Spectra with increased bandwidth and improved stability can be generated using an input envelope modulation of appropriate frequency and depth. The results are discussed in terms of the non-linear propagation dynamics and pump depletion.Comment: Aspects of this work were presented in Paper ThJ2 at OECC/ACOFT 2008, Sydney Australia 7-10 July (2008). Journal paper submitted for publication 30 July 200

Novel management paradigms for urogenital infections in pregnancy

S.A.&nbsp;Gasparyan1, A.A.&nbsp;Khazhbiev1,2, T.I.&nbsp;Derevyanko1 1Stavropol State Medical University, Stavropol, Russian Federation 2Nevinnomyssk City Hospital, Nevinnomyssk, Russian Federation In the last decade, our knowledge on normal vaginal microbiome has evolved greatly. Species composition of normal vaginal microflora of women of reproductive age is diverse and is in a dynamic equilibrium. The representation of various microbes in female urogenital tract is affected by various factors, i.e., genetic and environmental factors, general health, age, and hormonal profile. During pregnancy, compositional shift in vaginal microecosystem occurs with Candida spp. predominance thus resulting in higher rate of vulvovaginal candidiasis. When Candida albicans is identified in pregnant and non-pregnant women, azoles are recommended. When other fungi species are identified, polyene drugs as well as topical azoles (which are highly safe for fetus) are recommended. Nearly every tenth pregnant woman has asymptomatic bacteriuria. The lack of the treatment for asymptomatic bacteriuria in pregnant women is associated with higher (up to 30%) risk of pyelonephritis which threatens&nbsp; the health of both the mother and the child. In Russia, screening for asymptomatic bacteriuria in pregnant women after 14 weeks of pregnancy and etiological treatment for excessive bacterial colonization are recommended by clinical protocols. Short-course antibiotic treatment which provides minimum effects on fetus is preferable. Keywords: vagina, microbiota, pregnancy, vulvovaginal candidiasis, Candida, asymptomatic bacteriuria, antibiotic treatment. For citation: Gasparyan S.A., Khazhbiev A.A., Derevyanko T.I. Novel management paradigms for urogenital infections in pregnancy. Russian Journal of Woman and Child Health. 2019;2(4):296–300. </p

Research on processes of texture formation in "NiW substrate and TiN coating" system and creation of the new type textured paramagnetic substrates for HTS based on YBa₂Cu₃O₇

The paper investigates the processes of texture formation in thin-film two-component system based on paramagnetic Ni - 9.5 at. % W substrate with TiN coating. It is studied the influence of deposition time and pressure of nitrogen on the cubic texture formation in both components of "NiW/TiN" system by using XRD methods. It is observed the effect of re-orientation of crystal planes in the Ni - 9.5 at. % W tape exposed the influence of the coating that leads to a substantial enhancing the cubic texture of the paramagnetic substrate. It is also established that optimization of the conditions of thin TiN layer deposition makes it possible to obtain quasi single crystalline TiN coatings with cubic texture. These textured Ni - 9.5 at. % W/TiN substrates admit the epitaxial growth of high quality HTS films with the high current carrying capacity

Structural aspects of the phase and texture formation processes in thin-layer Ni-W/TiN systems which are perspective for creating high-temperature superconductors of the second generation

The investigation objective is searching for the new ways of controlling the structural properties of paramagnetic substrates for creating the high temperature coated superconductors for power applications. Processes of the texture formation in two-component Ni-W/TiN system is studied for paramagnetic Ni - 9.5 at. % W tape with TiN coating, which is deposited by ion-plasma deposition of Ti in nitrogen atmosphere. It is investigated by means of XRD analysis the influence of the deposition time and pressure of nitrogen on the phase and cubic texture formation in the both subsystems of Ni - 9.5 at. % W/TiN. It is found the effect of the crystal planes reorienting in the tape of Ni - 9.5 at. % W under the influence of TiN coating, that leads to a substantial strengthening of the cubic texture of the metallic ribbon. It is also observed the difference in the mechanism of coating formation during the deposition of TiN on the front and the back(shady) side of the substrate. It is also revealed that optimization of the conditions of thin TiN layer deposition makes it possible to obtain quasi single crystalline TiN coatings with a cubic texture. These textured Ni - 9.5 at. % W/TiN substrates admit the epitaxial growth of the high quality HTS films with high current carrying capacity

Researches and developments on production of Ni-W alloy based substrates for second generation high-temperature superconductors

The possibilities to prepare high quality substrates for second generation high temperature superconductors based on Ni—W alloys in the 0-9.5 at. % W concentration range was studied. Researches and developments were carried out in the following directions: a) Ni—W alloy synthesis; b) preparation of Ni—W alloy tapes by rolling with subsequent heat treatment; c) coating the tape by TiN layer. For the first time, the possibility was established to obtain the {001} cubic texture favour to YBa₂Cu₃O₇₋₈ superconductor subsequent epitaxial growth on the high W paramagnetic Ni—W tape surface by varying the regimes of TiN deposition