Presented work concerns with a sensitivity analysis of a harmonically excited bending vibration of a rotating couple of blades with a friction element with regard to the parameters of the friction characteristic. Either of the blades is discretized by FEM using beam elements and continuously distributed weight is concentrated in nodal points. The friction in central contact points between blade shrouds and the friction element is approximated by a continuous function depending on slip velocities of the shrouds relative to the friction element. Considered friction characteristic respects the micro-slip phase at the very low slip velocities and the macro-slip (full-slip) phase at the higher slip velocities. The values of the friction characteristic parameters are identified by comparison of the numerical simulations of a transient vibration with experiments used in IT AS CR. and Obsahuje seznam literatury
Gaits is one of the splendid functions, which concerns every human being. The standard gait is perceived as precisely controlled activities, based on the periodically coordinated, recurrent leg and trunk (torso) movements, which provide the relocation of the human body from one place to another with the minimal waste energy (Gage J.R., DeLuca P.A., Renshaw T.S. - gait definition) [2]. Different types of diseases cause the changes in gait pattern of the parients. The patients, who have the certain diseases since they were born and the acquired diseases have different deviations from the gait pattern. The conclusion is that there is no universal gait pattern.
The gait of the patients with implants differs from the gait pattern and in this case it depends on the implants type. Analysis and estimation of the gait of the people who have implants is problematic, that is why the paper presents the research connected with the gait diagnostics for people with implants.
In the paper an analysis of the influence of physical conditions inside the interelectrode gap (IEG) on the workpiece (WP) shape evolution has been presented. This problem has been solved on the basis of a two-dimensional model of an electrolyte and hydrogen mixture flow through the interelectrode gap (IEG). There has also been demonstrated general mathematical modeling algorithm as well as a numerical calculation scheme. and Obsahuje seznam literatury
The potential role of intestinal intraepithelial lymphocytes (i-IELs) in the generation of host protective immunity after helminth infection was investigated using the Trichinella spiralis (Owen, 1835)/mouse model. In this study we found a significant rise of TCRyô i-IELs (P < 0.001) concurrent with the jejunal goblet cells (GC) hyperplasia in T. spiralis-infected C57BL mice on day 4 p.i. However, no direct relationship between the kinetics of the increase in TCRy5+ i-IELs and T, spiralis expulsion was observed in infected mice. Taken together, these results implicate that γδ i-IELs probably perform a unique functions related to the regulation of the CiC proliferation accompanying T. spiralis gut infection. As is known, these TCRyS* i-IELs may release mediators or growth factors that in turn influence GC differentiation. With the use of dexamethason (DEX), a potent anti-inflammatory agent which also induces apoplotic ceil death in i-IELs, wc have confirmed that the expulsion of T. spiralis from the mouse gut is accompanied by an inflammatory response. Indeed, the GC are clearly involved in these phenomena, apparently under the regulation by TCRy8+ i-lEL-mediated responses, since DEX abrogated GC proliferation in T. spiralis-infected C57BL mice and subsequently augmented adult worm burden. Our data also show that the rejection of adult worms starts concurrently with a significant increase in TCRaß* and CDS* i-IELs (P < 0.05 and P < 0.01, respectively), namely by day 7 p.i. At the same time, CD4* cells significantly decreased (P < 0.05) in the intestinal epithelium of T. spira/ir-infected, ví uninfected mice. These results may indicate that the TCRaß4 and CDS* i-IELs act as effectors of anti-7’, spiralis defence reactions. The implications of these findings for the potential role of intestinal intraepithélial CD8 and TCRaß' cells in the pathogenesis of the intestinal lesions during T. spiralis gut infection are discussed.
The sequences of 10 conservative regions (CR) of minicircles of 6 selected isolates of freshwater fish try-panosomes have typical organization of this region with high degree of sequence conservation. The comparison with CRs of other trypanosomatids showed that freshwater fish trypanosomes represent a compact separate group within the genus Trypanosoma. The alignment of all sequences obtained revealed, however, the existence of 2 types of CRs in sequenced minicirclcs, with the differences concentrated in a short region. Taxonomic consequences of these results arc discussed.
This paper focuses on the implementation of the MLPG formulation for layered plates. For this purpose implementaton of homogenization theory was required and analyses were performed in order to obtain homogenized material properties of composite plates. Software for homogenization of material properties uses direct homogenization method that is based on volume average of stresses in the representative volume element (RVE). Homogenization is performed by linking MATLAB and ANSYS software. Obtained data are used in analyses carried out in own software which is based on the MLPG method. Strain, stress and displacement fields were evaluated. Results obtained by MLPG were compared with those obtained by FEM programs ANSYS and ABAQUS. and Obsahuje seznam literatury
Analytical solutions for static an dynamic stability parameters (Pcr and ωn) of an axially loaded nonuniform beam resting on a two parameter foundation are obtained using the recursive differentiation method (RDM) along with automatic differentiation. The analysis includes all cases of beam end conditions and indicates that the foundation stiffness influence is noticeable on both the critical load Per and natural frequency ωn in the case of slender beams. Also, it is found that the effect of the end conditions decreases as the slenderness parameter of the beam increases. In addition, the analysis concludes that neither the critical load nor the natural frequency corresponding to the first mode is always the smallest one in the case of beams of elastic foundations. The obtained solutions are verified and used to investigate the significance of different parameters on the critical loads and natural frequencies., Obsahuje seznam literatury a názvosloví, and V názvu článku je překlep ve slově differentation - správně differentiation (= chybí druhé i)
The study concentrates on analysis of heterogeneous rock mass deformations in the final years of underground coal extraction and during the revitalisation period after the end of mining. The research has been carried out in the Walbrzych Coal Basin where underground mining ceased at the end of the 20th Century. In the paper results of initial stages of ground deformation studies on a fragment of the Walbrzych mining grounds concerning analysis of benchmark height changes in a selected levelling line has been described. The results indicate ground subsidence in the period immediately after end of coal extraction and change to a steady uplift of the ground a few years later (2000-2008). Abnormal changes of heights in tectonic fault zones have also been observed. These could be related to heterogeneous rock mass reaction during the revitalisation period., Jan Blachowski, Stefan Cacoń and Wojciech Milczarek., and Obsahuje bibliografii
GPS permanent stations KRAW, KATO and ZYWI are part of so called Active Geodetic Network which covers entire area of Upper Silesian Coal Basin (USCB) in Poland and forms precise reference frame for geodetic and geodynamic applications. Moreover the above mentioned stations belong to EUREF Permanent Network. The stations, as datum points, play important role in precise positioning and geoid determination in area of USCB. The study of the stability of these points is one of the main components in precise monitoring of ground deformation in mining areas. The analysis of stability of permanent GPS stations KRAW, KATO and ZYWI are based on the coordinate time series obtained from the EUREF weekly solutions. The relative coordinate time series of weekly solutions for the vectors KRAW - KATO, KRAW - ZYWI , KATO - ZYWI are presented. The consistency, linearity, seasonal variations and jumps in the relative coordinate time series are discussed., Władysław Góral and Jacek Kudrys., and Obsahuje bibliografii