This paper presents some structural properties of a generalized Petri net (PN) with an algorithm to determine the (partial) conservativeness and (partial) consistency of the net. A product incidence matrix A=CCT or A~=CTC is defined and used to further improve the relations among PNs, linear inequalities and matrix analysis. Thus, based on Cramer's Rule, a new approach for the study of the solution of a linear system is given in terms of certain sub-determinants of the coefficient matrix and an efficient algorithm is proposed to compute these sub-determinants. The paper extends the common necessary and/or sufficient conditions for conservativeness and consistency in previous papers and some examples are designed to explain the conclusions finally.
Repeated geodetic observations were applied in mining location Louky near Karviná to detect surface changes from undermining in complex geo-mechanical conditions. Analyses of the subsidence magnitude and the length and direction of horizontal displacements showed that the subsidence trough was formed unevenly not only due to the position of the exploited local longwall panels and their different size but also showed a notable effect of the dominant tectonic fault. The significantly uneven development of the subsidence trough negatively affects line constructions. Terrain deformations of the road and stream pipeline were computed and classified into the building site categories according to the Czech standard ČSN 73 0039. The course of individual deformations in the monitored locality is influenced by a complex geo-mechanical situation. While the course of the subsidence curves is continuous at the observed pipeline and the classification of individual sections into building site categories corresponds with that, the road profile points out a more complex development of surface deformations. At the end of the observed period, 5 % of the profiles’ sections fell into category III (medium intensity), 49 % into category IV (moderate intensity) and 32 % stayed in category V (very moderate intensity of mining effects).
Using GNSS method, fixed points of an observation network were repeatedly surveyed on the surface of the undermined area. Below the surface, at the depth of c. 1 km, there were four mining panels exploited subsequently. The main reaction of the surface points to the changes in the rock massif and the movement of the points were different, according to their surface position, local geo-mechanical conditions etc. This paper analyses the time-dependence of the surface points mining subsidence and horizontal movements on the progress of the exploitation., Hana Doležalová, Vlastimil Kajzar, Kamil Souček and Lubomír Staš., and Obsahuje bibliografické odkazy
The aim of this study was to determine the accuracy and precision of McMaster method with Raynaud's modification in the detection of the eggs of the nematodes Toxocara canis (Werner, 1782) and Trichuris ovis (Abildgaard, 1795) in faeces of dogs. Four variants of McMaster method were used for counting: in one grid, two grids, the whole McMaster chamber and flotation in the tube. One hundred sixty samples were prepared from dog faeces (20 repetitions for each egg quantity) containing 15, 25, 50, 100, 150, 200, 250 and 300 eggs of T. canis and T. ovis in 1 g of faeces. To compare the influence of kind of faeces on the results, samples of dog faeces were enriched at the same levels with the eggs of another nematode, Ascaris suum Goeze, 1782. In addition, 160 samples of pig faeces were prepared and enriched only with A. suum eggs in the same way. The highest limit of detection (the lowest level of eggs that were detected in at least 50% of repetitions) in all McMaster chamber variants were obtained for T. canis eggs (25-250 eggs/g faeces). In the variant with flotation in the tube, the highest limit of detection was obtained for T. ovis eggs (100 eggs/g). The best results of the limit of detection, sensitivity and the lowest coefficients of variation were obtained with the use of the whole McMaster chamber variant. There was no significant impact of properties of faeces on the obtained results. Multiplication factors for the whole chamber were calculated on the basis of the transformed equation of the regression line, illustrating the relationship between the number of detected eggs and that of the eggs added to the sample. Multiplication factors calculated for T. canis and T. ovis eggs were higher than those expected using McMaster method with Raynaud modification.
A classification of possible models of the diamond grinding wheels destruction in the form of local breaking, shifting, and rotation of diamond grits, taking place independently, in sequence or in one time, has been presented. One has been stated, that destruction of the diamond wheels on the resin and metal bonds occurs generally as a result of local rotations of the diamond grits in the bond, the number of which amounts 50% of total number of grits, not participating in the process of cutting. and Uvádí se klasifikace možných modelů destrukce diamantových brusných kotoučů v podobě lokálního odlomení, posunu a rotace diamantových zrn, které se uplatňují nezávisle, postupně nebo současně. Je konstatováno, že destrukce diamantových kotoučů s organickou nebo kovovou vazbou se obecně vyskytuje jakožto výsledek lokálních rotací diamantových zrn ve vazbě, jejichž počet dosahuje 50 % celkového množství zrn neúčastnících se procesu řezání.
Based on the crystal structure and spectral properties of C-phycocyanin (C-PC) from cyanobacteria, models for complexes with 2 and 3 C-PC hexamer disks were built and the energy transfer dynamic properties were studied by the use of stochastic computer simulation approach. In addition, an experimental parameter of 0.056 ps-1, corresponding to a time constant of 18 ps, derived from the previous time-resolved measurement, was used for simulation of the energy transfer process from the three terminal symmetrically equivalent β84 chromophores of the core-linked disk to an α84 chromophore of the allophycocyanin (APC) core. The simulation showed: (1) The disk-to-disk energy transfer can be as fast as several picoseconds. (2) The energy transfer efficiencies from the first disk to the core would depend on the length of the rod (i.e. the number of disks). Efficiencies of 0.95, 0.87, and 0.75 were found for the rods with 1, 2 and 3 hexamer disks, respectively. (3) The energy transfer along a rod in a native phycobilisome (PBS) is probably very close to the one-way manner. It is the core of PBS that makes the excitation energy be transferred fast in a nearly one-way manner. and Jie Xie, Jing-quan Zhao, Chenghang Peng.
We have investigated the time profiles of flare heating function for selected flares based on the analysis of their evolutionary paths in the Emission Measure - Temperature diagrams. The emission measures and the temperatures werederived from the Ca XIX soft X-ray spectra observed by the Bent Crystal Spectrometer aboard the Solar Maximum Mission satellite. Interpretation of these diagrams allows to study the rate of energy deposition during both rise and decay phase of flares. The investigation of (EM-T) diagrams during
the decay phase allows furthermore for determination of effective length/cross-sectional area ratio of the flaring loop. We háve used the value of this ratio to derive the effective loop cross-sectional radius and the plasma density from deconvolved Fiat Crystal Spectrometer soft X-ray images.
Over a large range of the pressure, one cannot ignore the fact that the viscosity grows significantly (even exponentially) with increasing pressure. This paper concerns long-time and large-data existence results for a generalization of the Navier-Stokes fluid whose viscosity depends on the shear rate and the pressure. The novelty of this result stems from the fact that we allow the viscosity to be an unbounded function of pressure as it becomes infinite. In order to include a large class of viscosities and in order to explain the main idea in as simple a manner as possible, we restrict ourselves to a discussion of the spatially periodic problem.
The paper contains a sensitivity analysis of the influence of uncertainties in input hydrological, morphological and operating data required for a proposal for active reservoir conservation storage capacity and its achieved values. By introducing uncertainties into the considered inputs of the water management analysis of a reservoir, the subsequent analysed reservoir storage capacity is also affected with uncertainties. The values of water outflows from the reservoir and the hydrological reliabilities are affected with uncertainties as well. A simulation model of reservoir behaviour has been compiled with this kind of calculation as stated below. The model allows evaluation of the solution results, taking uncertainties into consideration, in contributing to a reduction in the occurrence of failure or lack of water during reservoir operation in low-water and dry periods.
Safe and effective loading of nuclear reactor fuel assemblies demand qualitative and quantitaive analysis of the relations between the coolant temperature in the fuel assembly outlet, measured by a thermocouple, and the mean temperature of the coolant in the thermocouple plane position. In the laboratory at the Institute of Thermal Power Engineering of the Slovak University of Technology in Bratislava, an experiemental physical fuel assembly model of the VVER 440 nuclear power plant with V 213 nuclear reactors was installed The aim of the measurements on the physical model was to analyze the temperature and velocity profiles in the fuel assembly outlet. The following article deals with the analyses of these measurements based on different mass flow of the water through a physical model of the fuel assembly outlet. The following arficle deals with the analysis of these measurements based on different discontinuity generated by cold water flowing through triplet tubes and central tube in plane 1, and the positioning of the mixing CFD grid simulations of a fuel assembly outlet. All analyses were validated by means of measurements on the physical model of the fuel assembly. and Obsahuje seznam literatury