Several multiaxial fatigue criteria have been developed and improved within the last couple of decades, but they are not very widely used in industrial applications. Many engineers and designers still use simple uniaxial criteria for multiaxial load cases. In order to test and validate / discard these uniaxial criteria on the basis of multiaxial load cases, the present work presents a comparison between several uniaxial criteria applied to a large set of experimental results for smooth unnotched samples tested under multiaxial loading. The effect of mean stress is also evaluated in order to determinate how it affects the final results. and Obsahuje seznam literatury
An observation network was built to observe the process of creating of a subsidence depression above exploited coal mining panels near Karviná. Points of the observation network were periodically surveyed by geodetic GPS method from 2006 to 2009. This method enables the evaluation of both vertical subsidence and horizontal shifts. Such complex evaluation of processes on the surface of the undermined area makes it possible to understand the progress of the subsidence depression caused by undermining. The results have shown on areas of irregular development of the subsidence depression. The irregularities are caused by a complicated tectonic situation and former exploitation in given locality and also active exploitation in the surroundings of given locality., Hana Doležalová, Vlastimil Kajzar, Kamil Souček and Lubomír Staš., and Obsahuje bibliografii
Water quality of the Cidlina river (right tributary of the Labe river was studied during two years (1997 - 1998). Besides the examination of hydrology and land use, the main resources of pollution were identified. Physical, chemical and biological parameters of water were measured in 10 profiles and water quality was evaluated according to Czech norms 75 7221 and put into the grade of purity. Pollution of upper part of river is not so bad but lower part is very polluted. High concentration of BOD5 correspond with biological parameters - alfa-mesosaprobita. At the end some tools and strategies are added to manage water more effectively. and V létech 1997 a 1998 byla sledována kvalita povrchové vody v Cidline (pravostranný přítok Labe). Kromě studia hydrologických parametrů a využívání krajiny (land use) byly zjištěny hlavní zdroje znečištění - města Jičín a Nový Bydžov. Fyzikálně-chemické a biologické charakteristiky vody byly měřeny na 10 říčních profilech a kvalita vody hodnocena podle CSN 75 7221 a zařazena do tříd čistoty. Horní část toku, méne znečištěná, náleží do III. - IV. třídy, silně znečištená dolní část do V. třídy čistoty. Zvýšené koncentraci BSK5 v celém toku odpovídá i kvalita makrozoobentosu - vetšinou α -mezosaprobita. V závěru jsou navržena opatření k zlepšení kvality vody.
Wild Arachis genotypes were analysed for chlorophyll a fluorescence, carbon isotope discrimination (ΔC), specific leaf area (SLA), and SPAD readings. Associations between different traits, i.e., SLA and SPAD readings (r =-0.76), SLA and ΔC (r = 0.42), and ΔC and SPAD readings (r = 0.30) were established. The ratio of maximal quantum yield of PSII photochemistry (Fv/Fm) showed a wider variability under water deficit (WD) than that after irrigation (IR). Genotypes were grouped according to the Fv/Fm ratio as: efficient, values between 0.80 and 0.85; moderately efficient, the values from 0.79 to 0.75; inefficient, the values < 0.74. Selected Selected genotypes were evaluated also for their green fodder yield: the efficient genotypes ranged between 3.0 and 3.8, the moderately efficient were 2.6 and 2.7, the inefficient genotypes were of 2.3 and 2.5 t ha-1 per year in 2008 and 2009, respectively. Leaf
water-relation traits studied in WD and IR showed that the efficient genotypes were superior in maintenance of leaf water-relation traits, especially, under WD. Potential genotypes identified in this study may enhance biomass productivity in the semiarid tropic regions., P. C. Nautiyal, A. L. Rathnakumar, G. Kulkarni, M. S. Sheshshayee., and Obsahuje bibliografii
The article presents a manuscript collection of texts of evangelical provenance that has recently been purchased in a German second-hand bookshop. According to a chronogram, this manuscript is likely to come from 1840. The manuscript consists of fifteen relatively independent text sections thematically related to the denominational controversies before and after the battle of White Mountain. The paper examines possible printed or manuscript models of individual parts and as well as their reflection in both earlier and more recent bibliographic literature. and David Mach.
This paper contains the method and results of calculation evapotranspiration and its structure - transpiration and evaporation from traditionally tilled and mulched soil. The data considered indicate that in the arid regions of territory under study the evapotranspiration when soil is mulched does not change significantly and only the relation between the transpiration and soil evaporation changes. In the wet regions, evapotranspiration decreases when the soil is mulched which can result in a certain disturbance of the natural structure of the hydrological cycle and possible overmoistening soils.
Both, severe hypo- or hyperthyroidism may alter hemodynamic parameters. The aim of our study was to ascertain, whether also distinct changes within normal range of free thyroxine (fT4) would be associated with an impairment of left ventricle function in patients with chronic heart failure. Hundred-forty-eight patients (m121, f27, mean age 63.8±1.14 years) with chronic heart failure, fT4 levels within the normal range (9-22 pmol/l) and without thyrostatics or substitution treatment. Degree of heart failure was quantified by plasma B-type natriuretic peptide (BNP) and N-terminal pro-BNP (NT-proBNP). Patients with fT4 in the range 11.9-14.6 pmol/l [optimal, 2nd-3th quintile] had significantly lower NT-proBNP (718±70.4 pg/ml), than those with fT4<11.8 [low-normal, bottom quintile](1236±223.6 pg/ml; p<0.03) and those with fT4 over 14.6 pmol/l [high-normal, top two quintiles] (1192±114.9 pg/ml; p<0.0002). These differences remain significant, also if adjusted for age, gender and other confounders; adjusted odds ratio was 1.30 (1.05-1.59) for optimal vs. low-normal and 1.27 (1.04-1.55) for optimal vs. high-normal. Similar statistical differences were also found in BNP, but only when optimal and high-normal fT4 ranges were compared. In conclusion, the severity of heart failure seems to be also influenced by only mild deviations of fT4 concentrations from optimal levels., O. Mayer Jr, J. Šimon, J. Čech, H. Rosolová, J. Hrbková, R. Pikner, L. Trefil., and Obsahuje bibliografii a bibliografické údaje
This paper is concerned with the problem of H∞ event-triggered output feedback control of discrete time piecewise-affine systems. Relying on system outputs, a piecewise-affine triggering condition is constructed to release communication burden. Resorting to piecewise Lyapunov functional and robust control techniques, sufficient conditions are built to ensure the closed-loop systems to be asymptotically stable with the prescribed H∞ performance. By utilizing a separation strategy, the static output feedback controller is solved by means of linear matrix inequalities. The validity of the proposed method are demonstrated by numerical examples.
Recent reports have indicated a considerably inactivated PSII in twig cortices, in spite of the low light transmittance of overlying periderms. Corresponding information for more deeply located and less illuminated tissues like xylem rays and pith are lacking. In this investigation we aimed to characterize the efficiency of PSII and its light sensitivity along twig depth, in conjunction with the prevailing light quantity and quality. To that aim, optical methods (spectral reflectance and transmittance, chlorophyll fluorescence imaging, low temperature fluorescence spectra) and photoinhibitory treatments were applied in cut twig sections of four tree species, while corresponding leaves served as controls. Compared to leaves, twig tissues displayed lower chlorophyll (Chl) levels and dark-adapted PSII efficiency, with strong decreasing gradients towards the twig center. The low PSII efficiencies in the inner stem were not an artifact due to an actinic effect of measuring beam or to an enhanced contribution of PSI fluorescence. In fact, the PSII/PSI ratios in cortices were higher and those in the xylem rays similar to that of leaves. Inner twig tissues were quite resistant to photoinhibitory treatments, tolerating irradiation levels several-fold higher than those encountered in their microenvironment. Moreover, the extent of high light tolerance was similar in naturally exposed and shaded twig sides. The results indicate an increasing, inherent and light-independent inactivation of PSII along twig depth. The findings are discussed on the basis of a recently proposed model for photosynthetic electron flow in twigs, taking into account the specific atmospheric and light microenvironment as well as the possible metabolic needs of such bulky organs. and C. Yiotis, Y. Petropoulou, Y. Manetas.
Because of the shortage of phycoerythrin (PE) gene sequences from rhodophytes, peBA encoding β- and α -subunits of PE from three species of red algae (Ceramium boydenn, Halymenia sinensis, and Plocamium telfariae) were cloned and sequenced. Different selection forces have affected the evolution of PE lineages. 8.9 % of the codons were subject to positive selection within the PE lineages (excluding high-irradiance adapted Prochlorococcus). More than 40 % of the sites may be under positive selection, and nearly 20 % sites are weakly constraint sites in high-irradiance adapted Prochlorococcus. Sites most likely undergoing positive selection were found in the chromophore binding domains, suggesting that these sites have played important roles in environmental adaptation during PE diversification. Moreover, the heterogeneous distribution of positively selected sites along the PE gene was revealed from the comparison of low-irradiance adapted Prochlorococcus and marine Synechococcus, which firmly suggests that evolutionary patterns of PEs in these two lineages are significantly different. and S. Qin, F. Q. Zhao, C. K. Tseng.