600 research outputs found
Thermal Stability of Hafnium Diboride Films, Obtained on Substrates of Steel 12X18H9T and Cutting Plate T15K6
Investigation results of the influence of high-temperature annealing in the air environment on the
phase structure and structure of hafnium diboride films, received on substrates from steel 12Х18Н9Т and
cutting plate Т15К6 are presented. It is shown that in the course of annealing on a surface of HfВ2 film the
oxide layer of HfО2, with monoclinic structure is formed. Thus, annealing temperature increase from 600 to
1000 С leads to increase in thickness of an oxide layer from 100 to 600 nanometers and to formation of a
multilayered covering of HfB2 - HfO2. On substrates of steel 12Х18Н9Т the coating is destructed at the
temperature higher on 800 C than for Т15К6.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3492
Multiple (inverse) binomial sums of arbitrary weight and depth and the all-order epsilon-expansion of generalized hypergeometric functions with one half-integer value of parameter
We continue the study of the construction of analytical coefficients of the
epsilon-expansion of hypergeometric functions and their connection with Feynman
diagrams. In this paper, we show the following results:
Theorem A: The multiple (inverse) binomial sums of arbitrary weight and depth
(see Eq. (1.1)) are expressible in terms of Remiddi-Vermaseren functions.
Theorem B: The epsilon expansion of a hypergeometric function with one
half-integer value of parameter (see Eq. (1.2)) is expressible in terms of the
harmonic polylogarithms of Remiddi and Vermaseren with coefficients that are
ratios of polynomials. Some extra materials are available via the www at this
http://theor.jinr.ru/~kalmykov/hypergeom/hyper.htmlComment: 24 pages, latex with amsmath and JHEP3.cls; v2: some typos corrected
and a few references added; v3: few references added
РЕЗУЛЬТАТЫ ЭТАПНОГО ЛЕЧЕНИЯ ПАЦИЕНТОВ С ПЕРИПРОТЕЗНОЙ ИНФЕКЦИЕЙ ПОСЛЕ ЭНДОПРОТЕЗИРОВАНИЯ КОЛЕННОГО СУСТАВА
Treatment of chronic periprosthetic joint infection (PJI) is connected with high reinfection rate and financial costs. Two stage reimplantation with the use of dynamic and static spacers on the first stage is an effective treatment algorithm of such complication.Purpose of the study – to evaluate the influence of a spacer type on infection eradication and intraoperative features of two-stage surgical treatment in patients with PJI after TKA.Material and methods. From year 2007 to 2015 161 patients with PJI were treated: 80 patients with dynamic spacers and 81 – with static spacers. The mean follow up period was 65 months (95% CI: 12–91). The mean age was 62 years (95% CI: 30–84). The outcomes included analysis of infection eradication effectiveness and intraoperative features (operation time, blood loss, type of implant). We excluded 57 patients with severe bone defects (AORI 2B, 3), reinfection after the first stage and, finally, analyzed 104 patients with appropriate including criteria.Results. Effectiveness of the first stage was 70,1%. The second stage demonstrated 90,1% effectiveness. There was statistically lower reinfection rate after the first stage in patients treated with dynamic spacer 88,1%, compared with 59.1% in patients with static spacers. The mean period between stages was 196 days. Sanation surgery with further implantation of dynamic spacer was followed by statistically (p0,02) lower blood loss – 522.6 ml (95% CI: 150–1300), compared with static spacers – 727.8 ml (698,1 ml (95% CI; 300–1600), but the operation time was comparable (p = 0.8): 140.2 (95% CI; 75–240) и 142.9 min (95% CI: 85–210) respectively. Revision knee arthroplasty after static spacer was followed by frequent (р0.05) use of extended surgical approach, constrained implants (p0,05) and long operation time (p0.02) compared with dynamic constructions.Conclusion. Two stage reimplantation with the use of dynamic spacers provides better infection control, knee function between stages, less traumatic sanation and revision knee arthroplasty. Inability to comply recommended interval between stages, due to specifics of financing, makes the implantation of dynamic spacers in patients with PJI on the first stage more preferable.Лечение пациентов с перипротезной инфекцией (ППИ) связано с повышенным риском рецидивов, а также со значительными финансовыми затратами. Этапное реэндопротезирование пациентов с использованием артикулирующих и блоковидных спейсеров является эффективным методом лечения подобных осложнений.Цель исследования – оценить влияние типа цементного антимикробного спейсера, используемого в ходе санирующего этапа, на эффективность эрадикации инфекции и интраоперационные показатели при лечении ППИ коленного сустава.Материал и методы. За период с 2007 по2015 г. этапное хирургическое лечение было выполнено 161 пациенту с ППИ коленного сустава. На этапе санации 80 пациентам был имплантирован артикулирующий спейсер, 81 – блоковидный. Средний период наблюдения составил 65 месяцев (95% ДИ: 12–91). Была проанализированы эффективность эрадикации инфекции и интраоперационные покзатели (время операции, кровопотеря, используемые хирургические доступы, степень связанности имплантированных эндопротезов). С целью объективизации сравнительного анализа из исследования были исключены 57 пациентов с массивными костными дефектами типов 2B и 3 по AORI, а также рецидивами ППИ. В конечном итоге были подвергнуты анализу результаты лечения 104 пациентов, удовлетворяющих следующим критериям включения: развитие ППИ после первичного эндопротезирования коленного сустава, наличие незначительных костных дефектов метаэпифизов (типы 1 и 2А по AORI) после удаления компонентов эндопротеза, отсутствие рецидивов ППИ после санирующей операции. Результаты. Эффективность санирующего этапа составила 70,1%, этапа реэндопротезирования – 90,1%. У пациентов с артикулирующими спейсерами эффективность составила 88,1% по сравнению с 59,1% у пациентов с блоковидными спейсерами. Средний интервал между этапами лечения – 196 дней. Этап санации у пациентов с артикулирующими спейсерами сопровождался статистически значимо (p0,02) меньшей кровопотерей (522,6 мл, 95% ДИ: 150–1300) по сравнению с блоковидными спейсерами (727,8 мл, 95% ДИ: 300–1600). При этом время операции было сопоставимым (p = 0,8): 140,2 (95% ДИ: 75–240) и 142,9 мин (95% ДИ: 85–210) соответственно. Реэндопротезирование после применения блоковидных спейсеров потребовало более частого применения расширенных доступов (p0,05), связанных конструкций (p0,05) и сопровождалось большей продолжительностью операции (p0,02).Выводы. Таким образом, основным преимуществом применения артикулирующих спейсеров на этапе санации является эффективная эрадикация инфекции, а поддержание подвижности и опороспособности конечности между этапами лечения значительно облегчает последующее реэндопротезирование и снижает его травматичность по сравнению с блоковидными спейсерами
Vacuum fluctuations and topological Casimir effect in Friedmann-Robertson-Walker cosmologies with compact dimensions
We investigate the Wightman function, the vacuum expectation values of the
field squared and the energy-momentum tensor for a massless scalar field with
general curvature coupling parameter in spatially flat
Friedmann-Robertson-Walker universes with an arbitrary number of toroidally
compactified dimensions. The topological parts in the expectation values are
explicitly extracted and in this way the renormalization is reduced to that for
the model with trivial topology. In the limit when the comoving lengths of the
compact dimensions are very short compared to the Hubble length, the
topological parts coincide with those for a conformal coupling and they are
related to the corresponding quantities in the flat spacetime by standard
conformal transformation. In the opposite limit of large comoving lengths of
the compact dimensions, in dependence of the curvature coupling parameter, two
regimes are realized with monotonic or oscillatory behavior of the vacuum
expectation values. In the monotonic regime and for nonconformally and
nonminimally coupled fields the vacuum stresses are isotropic and the equation
of state for the topological parts in the energy density and pressures is of
barotropic type. In the oscillatory regime, the amplitude of the oscillations
for the topological part in the expectation value of the field squared can be
either decreasing or increasing with time, whereas for the energy-momentum
tensor the oscillations are damping.Comment: 20 pages, 2 figure
Development of the BINP AMS complex at CCU SB RAS
The accelerator mass spectrometer created at BINP is installed at CCU “Geochronology of the cenazoic era” for sample dating by the ¹⁴С isotope. Present status of AMS complex and the results of experiments for radiocarbon concentration measurements in test samples are presented.Созданный в ИЯФ ускорительный масс-спектрометр установлен в ЦКП «Геохронология кайнозоя» для датирования образцов по изотопу ¹⁴С. Представлены текущее состояние комплекса УМС и результаты экспериментов по измерению концентрации радиоуглерода в тестовых образцах.Створений у ІЯФ прискорювальний мас-спектрометр встановлено в ЦКП «Геохронологія кайнозою» для датування зразків по ізотопу ¹⁴С. Представлено поточний стан комплексу УМЗ і результати експериментів з вимірювання концентрації радіовуглецю в тестових зразках
The influence of direct -meson production to the determination on the nucleon strangeness asymmetry via dimuon events in neutrino experiments
Experimentally, the production of oppositely charged dimuon events by
neutrino and anti-neutrino deep inelastic scattering (DIS) is used to determine
the strangeness asymmetry inside a nucleon. Here we point out that the direct
production of -meson in DIS may make substantial influence to the
measurement of nucleon strange distributions. The direct -meson production
is via the heavy quark recombination (HQR) and via the light quark
fragmentation from perturbative QCD (LQF-P). To see the influence precisely, we
compute the direct -meson productions via HQR and LQF-P quantitatively and
estimate their corrections to the analysis of the strangeness asymmetry. The
results show that HQR has stronger effect than LQF-P does, and the former may
influence the experimental determination of the nucleon strangeness asymmetry.Comment: 9 latex pages, 7 figure
Bianchi type I space and the stability of inflationary Friedmann-Robertson-Walker space
Stability analysis of the Bianchi type I universe in pure gravity theory is
studied in details. We first derive the non-redundant field equation of the
system by introducing the generalized Bianchi type I metric. This non-redundant
equation reduces to the Friedmann equation in the isotropic limit. It is shown
further that any unstable mode of the isotropic perturbation with respect to a
de Sitter background is also unstable with respect to anisotropic
perturbations. Implications to the choice of physical theories are discussed in
details in this paper.Comment: 5 pages, some comment adde
Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV
We report the results of a study of color coherence effects in ppbar
collisions based on data collected by the D0 detector during the 1994-1995 run
of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8
TeV. Initial-to-final state color interference effects are studied by examining
particle distribution patterns in events with a W boson and at least one jet.
The data are compared to Monte Carlo simulations with different color coherence
implementations and to an analytic modified-leading-logarithm perturbative
calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters
Observation of Orbitally Excited B_s Mesons
We report the first observation of two narrow resonances consistent with
states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar
collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the
Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed
as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+,
\bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1})
= 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let
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