The dynamics of the cellular composition of urine sediment in conditions of an artificial bladder

The evaluation of the urine cytological profile in the dynamics of adaptation of the orthotopic bladder to the functional properties of the urinary reservoir and determination of the connection between the cellular composition of the urine with the functional role of the formed from the intestinal fragment neocyst in experimental conditions and in humans. The material in experimental study were the results of a cytological study of the urine sediment obtained from 21 female pigs (mini-pigs). The portion of urine had received in experimental animals one month after orthotopic ileocystoplasty, 6 months and 1 year later and prepared as smear from the resulting precipitate. The level of lymphocytes, neutrophils, erythrocytes, as well as the superficial, intermediate and basal epitheliocytes evaluated during study. An analysis of the cell composition of centrifugal smears from the neocyst were performed in 21 patients with bladder cancer undergoing cystectomy and the formation of an orthotopic bladder, at various periods after surgery, from 3 months to 5 years. The preparation of a centrifugal sediment and the subsequent production of smears carried out as well as experimental animals

Superconductivity in multi-phase Mg-B-O compounds

Structures of MgB2-based materials manufactured under pressure (up to 2 GPa) by different methods having high superconducting performance and connectivity are multiphase and contain different Mg-B-O compounds. Some oxygen can be incorporated into MgB2 and boron into MgO structures, MgBx (X=4-20) inclusions contain practically no oxygen. Regulating manufacturing temperature, pressure, introducing additions one can influence oxygen and boron distribution in the materials and thus, affect the formation, amount and sizes of Mg-B-O and MgBx inclusions and changing type of pinning, pinning force and so affect critical current density jc. The boron concentration increase in initial Mg and B mixture allows obtaining sample containing 88.5 wt% of MgB12 with Tc of 37.4 K (estimated magnetically)

ОЦІНКА ПОТЕР ЕЛЕКТРОЕНЕРГІЇ В ТЯГОВІЙ МЕРЕЖІ МАГІСТРАЛЬНИХ ЗАЛІЗНИЦЬ

An indirect method of electric power losses determination in catenary has been examined. An example of solving such task with the help of specialized imitation model has been given and results of statistic analysis have been presented. Possible ways of using the obtained results have been exemplified.Рассмотрен косвенный метод определения потерь электроэнергии в тяговой сети. Приведен пример решения такой задачи с помощью специализированной имитационной модели и результаты статистического анализа полученных результатов. Показано возможное применение достигнутых результатов.Розглянуто непрямий метод визначення втрат електроенергії в тяговій мережі. Наведено приклад розв’язання такої задачі за допомогою спеціалізованої імітаційної моделі та результати статистичного аналізу отриманих результатів. Показане можливе застосування досягнутих результатів

Synthesis Pressure–Temperature Effect on Pinning in MgB2-Based Superconductors

International audienceThe volume pinning force, F p(max), increases with increasing synthesis or sintering pressure (0.1 MPa–2 GPa) in materials prepared at high temperature (1050 °C) while it stays practically unchanged in those prepared at low temperature (800 °C). The position of F p(max) can be shifted to higher magnetic fields by: (1) increasing the manufacturing pressure or decreasing the temperature (2) additions (Ti, SiC, or C, for example), and (3) in-situ preparation. Grain boundary pinning (GBP) dominates in materials prepared at low temperatures (600–800 °C), while high-temperature preparation induces strong point pinning (PP) or mixed pinning (MP) leading to outstanding properties. In materials produced by spark plasma sintering (SPS), the position of F p(max) is higher than expected for both grain boundary and point pinning. The distribution of boron and oxygen in MgB2 based material, which can changed by additions or the preparation conditions, significantly affects the type and strength of pining.Materials prepared under a pressure of 2 GPa with a nominal composition of Mg:7B or Mg:12B consist of 88.5 wt % MgB12, 2.5 wt % MgB2, 9 wt % MgO or 53 wt % MgB12, 31 wt % MgB20 16 wt % MgO, respectively. Their magnetic shielding fractions at low temperatures are 10 % and 1.5 %, with a transition temperature, T c of 37.4–37.6 K. Although their magnetic critical current density at zero field and 20 K was 2–5×102 A/cm2, they were found to be insulating on the macroscopic level

Synthesis Pressure–Temperature Effect on Pinning in MgB2-Based Superconductors

International audienc

Superconductivity in multi-phase Mg-B-O compounds

Structures of MgB2-based materials manufactured under pressure (up to 2 GPa) by different methods having high superconducting performance and connectivity are multiphase and contain different Mg-B-O compounds. Some oxygen can be incorporated into MgB2 and boron into MgO structures, MgBx (X=4-20) inclusions contain practically no oxygen. Regulating manufacturing temperature, pressure, introducing additions one can influence oxygen and boron distribution in the materials and thus, affect the formation, amount and sizes of Mg-B-O and MgBx inclusions and changing type of pinning, pinning force and so affect critical current density jc. The boron concentration increase in initial Mg and B mixture allows obtaining sample containing 88.5 wt% of MgB12 with Tc of 37.4 K (estimated magnetically)

Pinning in MgB2\hbox{MgB}_{2}- and YBaCuO-Based Superconductors: Effect of Manufacturing Pressure and Temperature

International audienceBulk MgB 2 - and YBaCuO-based materials are competitive candidates for applications. The properties of both compounds can be significantly improved by high temperature-high pressure preparation methods. The transformation of grain boundary pinning to point pinning in MgB 2 -based materials with increasing manufacturing temperature from 800 to 1050 ° C under pressures from 0.1 MPa to 2 GPa correlates well with an increase in critical current density in low and intermediate magnetic fields and with the redistribution of boron and oxygen in the material structure. As the manufacturing temperature increases (to 2 GPa), the discontinuous oxygen-enriched layers transform into distinct Mg-B-O inclusions, and the size and amount of inclusions of higher borides MgB X (X>;2) are reduced. The effect of oxygen and boron redistribution can be enhanced by Ti or SiC addition. The oxygenation of melt-textured YBa 2 Cu 3 O 7 - δ (MT-YBaCuO) under oxygen pressure (16 MPa) allows one to increase the oxygenation temperature from 440°C to 700-800°C, which leads to an increase of the twin density in the Y123 matrix and to a decrease of dislocations, stacking faults, and the density of microcracks, and as a result, to an increase of the critical current density, J c , and the trapped magnetic field. In MT-YBaCuO, practically free form dislocations and stacking faults and with a twin density of 22-35 μm -1 , J c of 100 kA/cm 2 (at 77 K, 0 T) has been achieved, and the importance of twins in Y123 for pinning was demonstrated experimentally

Pinning in MgB2\hbox{MgB}_{2}- and YBaCuO-Based Superconductors: Effect of Manufacturing Pressure and Temperature

International audienc