Dimensional Effects in Micro- and Nanostructural Changes in Grain and Intragrained Structure of Steel 45 at Static-pulse Treatment

Conducted macro-, micro- and nanostructured materials were investigated by the influence of sample sizes of steel 45 in the form of a parallelepiped, after intense static pulse processing in plastic deformation as in the single (150 J), and pulsed (25 J) impact with a frequency of 23 Hz. When all modes of processing bulk samples found structuring self-organized formation of dislocations. With a single exposure revealed as filling pearlite grains periodic dislocations (200 nm), and the formation of dislocation-free regions. When a periodic pulse treatment of the samples with transverse dimensions fold speed of propagation of elastic waves and shock waves as well as the related transport velocity of dislocations turns shockwave mechanism causing the formation of alternating strips of ferritic and pearlite walls (25 microns), wherein the pearlite wall completely or partially filled with dislocations

Development of mathematical and experimental model of neutron radiography set up

Perspectives of mathematical modeling usage for neutron radiography set ups development are considered. Results of the calculation of neutron passing through plane polyethylene layer are given.Розглянуто перспективи використання методів математичного моделювання для створення установок для нейтронної радіографії. Наведено результати розрахунку проходження нейтронів через плоский шар поліетилену.Рассмотрены перспективы использования методов математического моделирования для создания установок для нейтронной радиографии. Приведены результаты расчета прохождения нейтронов через плоский слой полиэтилена

Coronal Shock Waves, EUV waves, and Their Relation to CMEs. I. Reconciliation of "EIT waves", Type II Radio Bursts, and Leading Edges of CMEs

We show examples of excitation of coronal waves by flare-related abrupt eruptions of magnetic rope structures. The waves presumably rapidly steepened into shocks and freely propagated afterwards like decelerating blast waves that showed up as Moreton waves and EUV waves. We propose a simple quantitative description for such shock waves to reconcile their observed propagation with drift rates of metric type II bursts and kinematics of leading edges of coronal mass ejections (CMEs). Taking account of different plasma density falloffs for propagation of a wave up and along the solar surface, we demonstrate a close correspondence between drift rates of type II bursts and speeds of EUV waves, Moreton waves, and CMEs observed in a few known events.Comment: 30 pages, 15 figures. Solar Physics, published online. The final publication is available at http://www.springerlink.co

Faraday rotation in graphene

We study magneto--optical properties of monolayer graphene by means of quantum field theory methods in the framework of the Dirac model. We reveal a good agreement between the Dirac model and a recent experiment on giant Faraday rotation in cyclotron resonance. We also predict other regimes when the effects are well pronounced. The general dependence of the Faraday rotation and absorption on various parameters of samples is revealed both for suspended and epitaxial graphene.Comment: 10 pp; v2: typos corrected and references added, v3, v4: small changes and more reference

Study of the process e+e−→3(π+π−) in the c.m. energy range 1.5–2.0 GeV with the CMD-3 detector

AbstractThe cross section of the process e+e−→3(π+π−) has been measured using a data sample of 22 pb−1 collected with the CMD-3 detector at the VEPP-2000 e+e− collider. 7956 signal events are selected in the center-of-mass energy range 1.5–2.0 GeV. The measured cross section exhibits a sharp drop near the pp¯ threshold. A first study of dynamics of six-pion production has been performed

Study of the Solubility of Furazolidone from Solid Dispersions with Polyvinylpyrrolidone

Abstract: The effect of solid dispersions (SDs) on the solubility of furazolidone is studied. Furazolidone and its SDs with polyvinylpyrrolidone (PVP), PVP-10 000, PVP-12 600, and PVP-24 000 are examined. When using SDs, the solubility and dissolution rate of the nitrofuran derivative is increased. The solubility of furazolidone from SD is increased by a factor of 1.1 to 1.6. The dissolution rate of SDs is increased by a factor of 1.8 to 2.8. The complex of physicochemical methods of investigation suggests that an increase in solubility from SDs is caused by the loss of crystallinity and the formation of a solid solution of furazolidone during the preparation of SDs, as well as the solubilizing effect of the polymer during the subsequent dissolution of the SD in water. The results can be used in the development of hydrophilic soft and fast dissolving solid dosage forms of furazolidone with increased release and bioavailability. © 2020, Allerton Press, Inc

ИЗУЧЕНИЕ РАСТВОРИМОСТИ ФУРАЗОЛИДОНА ИЗ ТВЕРДЫХ ДИСПЕРСИЙ С ПОЛИВИНИЛПИРРОЛИДОНОМ

The effect of solid dispersions (SD) on the solubility of furazolidone was determined. We investigated furazolidone and its SD with polyvinylpyrrolidone (PVP)-10000, -12600 and -24000. The preparation of SD increases the solubility and dissolution rate of the nitrofuran derivative. The solubility of furazolidone from SD increases by 1,1-1,6 times. Dissolution rate of SD increases by 1,8-2,8 times. The complex of physical and chemical methods of research suggests that the increase in solubility of SD is due to the loss of crystallinity and the formation of a solid solution of furazolidone in the preparation of SD, as well as the solubilizing effect of the polymer in the subsequent dissolution of SD in water. The results can be used in the development of hydrophilic soft and fast-soluble solid dosage forms of furazolidone with increased release and bioavailability.Изучено влияние твердых дисперсий (ТД) на растворимость фуразолидона. Исследованы: фуразолидон и его ТД с поливинилпирролидоном (ПВП): ПВП-10000, ПВП-12600 и ПВП-24000. При использовании ТД повышается растворимость и скорость растворения производного нитрофурана. Растворимость фуразолидона из ТД увеличивается в 1,1-1,6 раза. Скорость растворения из ТД повышается в 1,8-2,8 раза. Комплекс физико-химических методов исследования позволяет предположить, что повышение растворимости из ТД объясняется потерей кристалличности и образованием твердого раствора фуразолидона при получении ТД, а также солюбилизирующим действием полимера при последующем растворении ТД в воде. Полученные результаты могут быть использованы при разработке гидрофильных мягких и быстрорастворимых твердых лекарственных форм фуразолидона с повышенными высвобождением и биодоступностью