Phase formation and characteristics of dysprosium titanate pellets prepared by solid state synthesis

Dysprosium titanate have been developed and used as absorbing material for control rods of thermal neutron nuclear reactors. The study results of phase formation kinetics in the pellets prepared from powder mixtures composition 1 (50 mol.% TiO₂ + 50 mol.% Dy₂O₃) and composition 2 (56 mol.% TiO₂ + 44 mol.% Dy₂O₃) after sintering at temperatures of 1250...1650 °C in an air are presented. It is shown that initial mixture composition affects the phase composition of sintering dysprosium titanate pellets. Also, it was revealed the formation of high-temperature radiation-resistant fluorite phase of Dy₂TiO₅ using composition 1 powder mixture. Two-stage sintering with partial synthesis allows obtaining fine-grained dysprosium titanate pellets with high density of 7.1 g/cm³ and low open porosity.Розроблено титанат диспрозію, який використовується в якості поглинаючого матеріалу для регулюючих стрижнів ядерних реакторів на теплових нейтронах. Наведено результати дослідження кінетики фазоутворення в матеріалі таблеток із порошкових сумішей складу 1 (50 мол.% TiO₂ + 50 мол.% Dy₂O₃) та складу 2 (56 мол.% TiO₂ + 44 мол.% Dy₂O₃) після спікання за температур 1250…1650 °C в повітряній атмосфері. Показано, що склад вихідної суміші впливає на фазовий склад і співвідношення фаз у матеріалі, який синтезується. Зафіксовано утворення радіаційно стійкої високотемпературної фази зі структурою флюориту (Dy₂TiO₅-f) при використанні суміші складу 1. Використання схеми двостадійного спікання з частковим синтезом матеріалу на першій стадії забезпечує одержання таблеток із Dy₂TiO₅ щільністю 7,1 г/см³ з дрібнозернистою структурою та низьким значенням відкритої пористості.Разработан титанат диспрозия, который используется в качестве поглощающего материала для регулирующих стержней ядерных реакторов на тепловых нейтронах. Представлены результаты исследования кинетики фазообразования в материале таблеток из порошковых смесей состава 1 (50 мол.% TiO₂ + 50 мол.% Dy₂O₃) и состава 2 (56 мол.% TiO₂ + 44 мол.% Dy₂O₃) после спекания при температурах 1250…1650 °C в воздушной атмосфере. Показано, что состав исходной смеси влияет на фазовый состав и соотношение фаз в синтезируемом материале. Зафиксировано образование радиационнo стойкой высокотемпературной фазы со структурой флюорита (Dy₂TiO₅-f) при использовании смеси состава 1. Применение схемы двухстадийного спекания с частичным синтезом материала на первой стадии обеспечивает получение таблеток из Dy₂TiO₅ плотностью 7,1 г/см³ с мелкозернистой структурой и низким значением открытой пористости

Матриксины 2, 7 и 9 при раке молочной железы: выяснение возможной связи с концентрацией белка HER-2/neu

The comparative analysis of the quantity of matrix metalloproteinases (MMP) 2,7 and 9 in breast cancer is carried out; the concentration of sex hormones receptors and protein HER-2/neu are determined. Authentically high values MMP-2 and MMP-7 are found in a tumor tissue in contrast to the normal one. The elevated concentration of ММР-2 in a tumor is connected with receptor status (p < 0,05). The highest values of concentration ММР-7 and ММP- 9 are found at RE-, RP- and HER-2/neu + tumors, and also in the tumors with the size more than 4,0 cm.Проведен сравнительный анализ содержания матриксных металлопротеиназ (ММП) 2,7 и 9 в опухолевых тканях молочной железы и гистологически неизмененной ткани, определено содержание рецепторов половых гормонов, белка her-2/neu. Достоверно высокие значения ММП-2 и -7 обнаружены в ткани опухоли по сравнению с гистологически неизмененной тканью. Повышение концентраций ММР 2 в опухоли связано с рецепторным статусом опухоли (p < 0,05). Наиболее высокие значения концентраций ММР-7 и ММР-9 обнаружены при РЭ-, РП- и HER-2/neu+ опухолях, а также в новообразованиях размером более 4,0 см

Radioheliograph observations of microwave bursts with zebra structures

The so-called zebra structures in radio dynamic spectra, specifically their frequencies and frequency drifts of emission stripes, contain information on the plasma parameters in the coronal part of flare loops. This paper presents observations of zebra structures in a microwave range. Dynamic spectra were recorded by Chinese spectro-polarimeters in the frequency band close to the working frequencies of the Siberian Solar Radio Telescope. The emission sources are localized in the flare regions, and we are able to estimate the plasma parameters in the generation sites using X-ray data. The interpretation of the zebra structures in terms of the existing theories is discussed. The conclusion has been arrived that the preferred generation mechanism of zebra structures in the microwave range is the conversion of plasma waves to electromagnetic emission on the double plasma resonance surfaces distributed across a flare loop.Comment: 18 pages, 7 figure

Work status of 5 MeV 300 kW electron accelerator

Design work has been completed for the accelerating structure of high-power electron accelerator with 5 MeV, 300 kW, 176 MHz parameters. The structure is being produced in BINP workshop. The paper presents the design of the accelerating structure which consists of a chain of coaxial cavities, and block diagram of experimental workbench. Structure of the main accelerator blocks and their degree of fabrication are viewed.Закончены проектные работы по ускоряющей структуре мощного электронного ускорителя 5 МэВ, 300 кВт, 176 МГц и ведется ее изготовление в опытном производстве Института. Дается описание конструкции ускоряющей структуры, состоящей из цепочки связанных коаксиальных резонаторов. Приводится блок-схема испытательного стенда, рассматривается устройство отдельных узлов ускорителя и состояние их готовности.Закінчено проектні роботи із прискорювальної структури потужного електронного прискорювача 5 МеВ, 300 кВт, 176 МГц і ведеться її виготовлення в дослідному виробництві інституту. Дається опис конструкції прискорювальної структури, що складається з ланцюжка зв'язаних коаксіальних резонаторів. Приводиться блок-схема іспитового стенда, розглядається будова окремих вузлів прискорювача і стан їх готовності

Study of the lineshape of the chi(c1) (3872) state

A study of the lineshape of the chi(c1) (3872) state is made using a data sample corresponding to an integrated luminosity of 3 fb(-1) collected in pp collisions at center-of-mass energies of 7 and 8 TeV with the LHCb detector. Candidate chi(c1)(3872) and psi(2S) mesons from b-hadron decays are selected in the J/psi pi(+)pi(-) decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting between the chi(c1 )(3872) and psi(2S) states, Delta m, and the width of the chi(c1 )(3872) state, Gamma(Bw), are determined to be (Delta m=185.598 +/- 0.067 +/- 0.068 Mev,)(Gamma BW=1.39 +/- 0.24 +/- 0.10 Mev,) where the first uncertainty is statistical and the second systematic. Using a Flatte-inspired model, the mode and full width at half maximum of the lineshape are determined to be (mode=3871.69+0.00+0.05 MeV.)(FWHM=0.22-0.04+0.13+0.07+0.11-0.06-0.13 MeV, ) An investigation of the analytic structure of the Flatte amplitude reveals a pole structure, which is compatible with a quasibound D-0(D) over bar*(0) state but a quasivirtual state is still allowed at the level of 2 standard deviations

Measurement of the CKM angle γγ in B±→DK±B^\pm\to D K^\pm and B±→Dπ±B^\pm \to D π^\pm decays with D→KS0h+h−D \to K_\mathrm S^0 h^+ h^-

A measurement of $CP$-violating observables is performed using the decays $B^\pm\to D K^\pm$ and $B^\pm\to D \pi^\pm$, where the $D$ meson is reconstructed in one of the self-conjugate three-body final states $K_{\mathrm S}\pi^+\pi^-$ and $K_{\mathrm S}K^+K^-$ (commonly denoted $K_{\mathrm S} h^+h^-$). The decays are analysed in bins of the $D$-decay phase space, leading to a measurement that is independent of the modelling of the $D$-decay amplitude. The observables are interpreted in terms of the CKM angle $\gamma$. Using a data sample corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$ collected in proton-proton collisions at centre-of-mass energies of $7$, $8$, and $13\,\text{TeV}$ with the LHCb experiment, $\gamma$ is measured to be $\left(68.7^{+5.2}_{-5.1}\right)^\circ$. The hadronic parameters $r_B^{DK}$, $r_B^{D\pi}$, $\delta_B^{DK}$, and $\delta_B^{D\pi}$, which are the ratios and strong-phase differences of the suppressed and favoured $B^\pm$ decays, are also reported

Measurement of CP asymmetries and branching fraction ratios of B− decays to two charm mesons

The $CP$ asymmetries of seven $B^-$ decays to two charm mesons are measured using data corresponding to an integrated luminosity of $9\text{fb}^{-1}$ of proton-proton collisions collected by the LHCb experiment. Decays involving a $D^{*0}$ or $D^{*-}_s$ meson are analysed by reconstructing only the $D^0$ or $D^-_s$ decay products. This paper presents the first measurement of $\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0)$ and $\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0})$, and the most precise measurement of the other five $CP$ asymmetries. There is no evidence of $CP$ violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.The CP asymmetries of seven B$^{−}$ decays to two charm mesons are measured using data corresponding to an integrated luminosity of 9 fb$^{−1}$ of proton-proton collisions collected by the LHCb experiment. Decays involving a D$^{*0}$ or ${D}_s^{\ast -}$ meson are analysed by reconstructing only the D$^{0}$ or ${D}_s^{-}$ decay products. This paper presents the first measurement of $\mathcal{A} ^{CP}$(B$^{−}$→${D}_s^{\ast -}$D$^{0}$) and $\mathcal{A} ^{CP}$(B$^{−}$→${D}_s^{-}$D$^{∗0}$), and the most precise measurement of the other five CP asymmetries. There is no evidence of CP violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured.[graphic not available: see fulltext]The $CP$ asymmetries of seven $B^-$ decays to two charm mesons are measured using data corresponding to an integrated luminosity of $9\text{ fb}^{-1}$ of proton-proton collisions collected by the LHCb experiment. Decays involving a $D^{*0}$ or $D^{*-}_s$ meson are analysed by reconstructing only the $D^0$ or $D^-_s$ decay products. This paper presents the first measurement of $\mathcal{A}^{CP}(B^- \rightarrow D^{*-}_s D^0)$ and $\mathcal{A}^{CP}(B^- \rightarrow D^{-}_s D^{*0})$, and the most precise measurement of the other five $CP$ asymmetries. There is no evidence of $CP$ violation in any of the analysed decays. Additionally, two ratios between branching fractions of selected decays are measured

Helium identification with LHCb

The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

Momentum scale calibration of the LHCb spectrometer

For accurate determination of particle masses accurate knowledge of the momentum scale of the detectors is crucial. The procedure used to calibrate the momentum scale of the LHCb spectrometer is described and illustrated using the performance obtained with an integrated luminosity of 1.6 fb-1 collected during 2016 in pp running. The procedure uses large samples of J/ψ → μ + μ - and B+ → J/ψ K + decays and leads to a relative accuracy of 3 × 10-4 on the momentum scale