Об инвариантности кинематических базисных матриц планетарных рядов при анализе кинематики трансмиссий транспортных средств

Предложена универсальная матричная методика расчета кинематики планетарных механизмов. Показано, что кинематические матричные системы планетарных механизмов, несмотря на отличие в записи с различными значениями характерных параметров сателлитов, инвариантны по отношению к вектору неизвестных.The universal matrix design procedure of kinematics of planetary mechanisms is offered. It is shown, that kinematics matrix systems of planetary mechanisms, despite of distinction in record with different values of characteristic parameters of satellites, invariance in relation to a vector of unknown persons

Dynamics of suspensions of hydrodynamically structured particles: Analytic theory and experiment

We present an easy-to-use analytic toolbox for the calculation of short-time transport properties of concentrated suspensions of spherical colloidal particles with internal hydrodynamic structure, and direct interactions described by a hard-core or soft Hertz pair potential. The considered dynamic properties include self-diffusion and sedimentation coefficients, the wavenumber-dependent diffusion function determined in dynamic scattering experiments, and the high-frequency shear viscosity. The toolbox is based on the hydrodynamic radius model (HRM) wherein the internal particle structure is mapped on a hydrodynamic radius parameter for unchanged direct interactions, and on an existing simulation data base for solvent-permeable and spherical annulus particles. Useful scaling relations for the diffusion function and self-diffusion coefficient, known to be valid for hard-core interaction, are shown to apply also for soft pair potentials. We further discuss extensions of the toolbox to long-time transport properties including the low-shear zero-frequency viscosity and the long-time self-diffusion coefficient. The versatility of the toolbox is demonstrated by the analysis of a previous light scattering study of suspensions of non-ionic PNiPAM microgels [Eckert et al., J. Chem. Phys., 2008, 129, 124902] in which a detailed theoretical analysis of the dynamic data was left as an open task. By the comparison with Hertz potential based calculations, we show that the experimental data are consistently and accurately described using the Verlet-Weis corrected Percus-Yevick structure factor as input, and for a solvent penetration length equal to three percent of the excluded volume radius. This small solvent permeability of the microgel particles has a significant dynamic effect at larger concentrations.Comment: 25 pages, 24 figure

Physical and chemical features of hydrophilic microarc biocoatings based on substituted hydroxyapatite

The physical and chemical properties as topography, morphology, chemical composition and wettability of microarc calcium phosphate coatings based on Zn- and Cu- substituted hydroxyapatite on the Ti-40mas.%Nb alloy surface has been investigated. It have been found that calcium phosphate coatings on Ti-40mas.%Nb alloy produced under 200 V have X-ray amorphous state and as consequence high rate of dissolution. The phase composition of the coatings produced under 300 V is presented the following phases: CaHPO4,beta-Ca[2]P[2]O[7], Ca[2]Nb[2]O[7], NbO[2], Nb[2]O[5], TiO[2]. It has been shown that the biocoatings are very hydrophilic

Aggregate real exchange rate persistence through the lens of sectoral data

15 páginas, 2 figuras, 3 tablas.-- El pdf es la versión pre-print del artículo.-- Trabajo presentado a la conferencia "Microeconomic Sources of Real Exchange Rates" (Vanderbilt University-USA, 2010).A novel approach to analyzing real exchange rate (RER) persistence and its sources is presented. Using highly disaggregated data for a group of EU-15 countries, it is shown that the distribution of sectoral persistence is highly heterogeneous and skewed to the right, so that a limited number of sectors are responsible for the high levels of persistence observed at the aggregate level. Quantile regression has been employed to investigate whether traditional theories, such as the lack of arbitrage due to nontradability or imperfect competition combined with price stickiness, are able to account for the slow reversion to parity of RERs.Financial support from the Spanish Government CICYT projects SEJ2006-00369 and ECO2008-03040Peer reviewe