Accurate measurement of shallow flows is important for hydraulics, hydrology and water resources management. The objective of this paper is to discuss a technique for shallow flow and overland flow velocity estimation that uses infrared thermography. Laboratory flumes and different bare, vegetated and paved field surfaces were used to test the technique. Results show that shallow flow surface velocities estimated using thermal tracers and infrared technology are similar to estimates obtained using the Acoustic Doppler Velocimeter; similar results were also obtained for overland flow velocity estimates using thermography, here comparing with the dye tracer technique. The thermographic approach revealed some potential as a flow visualization technique, and leaves space for future studies and research.
The paper sketches an analysis of the notion of a self-fulfilling belief in terms of doxastic modal logic. We point out a connection between self-fulfilling beliefs and Moore’s paradox. Then we look at self-fulfilling beliefs in the context of neighborhood semantics. We argue that the analysis of several interesting self-fulfilling beliefs has to make essential use of propositional quantification., Příspěvek načrtává analýzu pojmu sebe-naplňující víry v podmínkách doxastické modální logiky. Poukazujeme na souvislost mezi seberealizujícími se víry a Moorovým paradoxem. Pak se podíváme na sebe-naplňující přesvědčení v kontextu sémantiky sousedství. Tvrdíme, že analýza několika zajímavých sebe-naplňujících přesvědčení musí nezbytně využít výrokové kvantifikace., and Igor Sedlár
The paper presents validation of a mathematical model describing the friction factor by comparing the predicted and measured results in a broad range of solid concentrations and mean particle diameters. Three different types of solids, surrounded by water as a carrier liquid, namely Canasphere, PVC, and Sand were used with solids density from 1045 to 2650 kg/m3, and in the range of solid concentrations by volume from 0.10 to 0.45. All solid particles were narrowly sized with mean particle diameters between 1.5 and 3.4 mm. It is presented that the model predicts the friction factor fairly well. The paper demonstrates that solid particle diameter plays a crucial role for the friction factor in a vertical slurry flow with coarse solid particles. The mathematical model is discussed in reference to damping of turbulence in such flows. As the friction factor is below the friction for water it is concluded that it is possible that the effect of damping of turbulence is included in the KB function, which depends on the Reynolds number.
The paper describes results of validation of authors' recently proposed formulae for sediment transport and bed friction in the upper plane bed regime using laboratory experiments in a pressurized pipe. Flows of mixture of water and fine to medium ballotini (d50 = 0.18 mm) were observed in a rectangular pipe (51 x 51 mm) with a deposit at the bottom of the pipe. A comparison of test results with transport-formula predictions shows a satisfactory match confirming a good prediction ability of the proposed transport formula at high bed shear. A prediction ability of the friction formulae appears to be less convincing but still reasonable. A joint use of the formulae for transport and friction predicts the delivered concentration of transported sediment within the accuracy range of ± 40 per cent for flows in which transported sediments strongly affect the bed friction, i.e. for flows with delivered concentration of sediment higher than say 3 per cent.
In this paper, I investigate the scalar semantics of evaluative adjective in general, and of good in particular. Lassiter (2017) has argued that good, when taking propositions as arguments, has an interval scale. I argue that there’s evidence in support of the view that good, when taking individuals as argument, has a scale that is stronger than interval, but weaker than ratio. In particular, I propose that individual-level good has a “round” ratio scale, which allows a broader set of ratio transformations than standard ratio scales. This conclusion is consistent with the fact that good admits round ratio modifiers (twice as good), but eschews precise ones (# 1.38x as good). An important consequence of this view is that the scales of individual and propositional-level good are severed.
The processing of ombrographic data from 29 meteorological stations of the Czech Hydrometeorological Institute (CHMI), according to the terms of the Universal Soil Loss Equation for calculating long term loss of soil through water erosion, erosion hazard rains and their occurrence have been selected, with their relative amount and erosiveness - R-Factors determined for each month and years. By comparing the value of the time division of the R-Factor in the area of the Czech Republic and in selected areas of the USA it has been demonstrated that this division may be applied in the conditions of the Czech Republic. For the Czech Republic it is recommended to use the average value R = 40 based on the original evaluation.
The objective of this study is to analyse the spatial variability of seasonal flood occurrences in the Upper Danube region for the period 1961-2010. The analysis focuses on the understanding of the factors that control the spatial variability of winter and summer floods in 88 basins with different physiographic conditions. The evaluation is based on circular statistics, which compare the changes in the mean date and in the seasonal flood concentration index within a year or predefined season. The results indicate that summer half-year and winter half-year floods are dominant in the Alps and northern Danube tributaries, respectively. A comparison of the relative magnitude of flood events indicates that summer half-year floods are on average more than 50% larger than floods in winter. The evaluation of flood occurrence showed that the values of seasonal flood concentration index (median 0.75) in comparison to the annual floods (median 0.58) shows higher temporal concentration of floods. The flood seasonality of winter events is dominant in the Alps; however, along the northern fringe (i.e. the Isar, Iller and Inn River) the timing of winter half-year floods is diverse. The seasonal concentration of summer floods tends to increase with increasing mean elevation of the basins. The occurrence of the three largest summer floods is more stable, i.e. they tend to occur around the same time for the majority of analysed basins. The results show that fixing the summer and winter seasons to specific months does not always allow a clear distinction of the main flood generation processes. Therefore, criteria to define flood typologies that are more robust are needed for regions such as the Upper Danube, with large climate and topographical variability between the lowland and high elevations, particularly for the assessment of the effect of increasing air temperature on snowmelt runoff and associated floods.