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This paper presents the results of a study of reversal hypothesis phenomena observed within riffles and pool sequences on a 1.1 km long reach of the Skawica-Jalowiecki Stream. The Skawica-Jalowiecki is a flashy mountain stream with an alluvial bed that transports sediment during frequent floods. The study reach is situated just below the border of the Babia-Gora National Park in Polish Carpathians, which provides a good, undisturbed research site. It was found that Q=4.27 m3s-1, Q=2.43 m3s-1 velocities and shear stresses in pools were highest over riffles during spring floods. It was also observed that unit stream power above the pools was bigger than that found in the riffles.
A long wave run-up theory is applied to the modelling of wave-induced flow velocities, sediment transport rates and bottom changes in a swash zone. First, the properties of the water tongue motion and the resulting lithodynamic response are analysed theoretically. Next, an attempt is made to run the model for the natural conditions encountered on the southern Baltic Sea coast. The Lagrangian swash velocities are used to determine the Eulerian phase-resolved bed shear stresses with a momentum integral method, after which the motion of sand is described by the use of a two-layer model, comprising bedload and nearbed suspended load. Seabed evolution is then found from the spatial variability of the net sediment transport rates. The results presented are limited to cases of the small-amplitude waves that seem to be responsible for accretion on beaches.
The paper provides a simple and analytical method which can be used to give estimates of the wave-induced bottom shear stress for very rough beds and mud beds in shallow water based on wind statistics in deep water. This is exemplified by using long-term wind statistics from the northern North Sea, and by providing examples representing realistic field conditions. Based on, for example, global wind statistics, the present results can be used to make estimates of the bottom shear stress in shallow water.
The milk along with xanthan at levels 0, 1.9, 3.9, 5.9, 7.9, 9.9 and 0.1 and 0.2 % (No 1 (control) to 11 respectively) as egg replacement were used for preparation of mayonnaise. Creaming index, heat stability, physical stability and rheological properties of samples over a were investigated. Also flow behavior of samples were fitted to Power law, Herschel- Bulkley and Casson models. It was found that addition milk along with xanthan to mayonnaise protected from phase separation in comparison to control sample. All the samples had stability higher than 99% except samples 1, 4, 5 and 6. The highest stability was recorded for sample No 11 (99.98%) and the lowest for 5 (74.95%) that compared with control sample had significant differences (p> 0.05). All the samples except No 1 and 5 showed heat stability higher than 99 % and the highest stability recorded for No 11 ( 99.72%) and the lowest for No 5 (67.42 %) and in comparison with control were significantly different (p> 0.05). Apparent viscosity decreased with increase the egg replacement from 40% to 80%, as the highest and lowest viscosity observed in samples contain 100% and 80% replacement respectively. All samples showed shear-thinning behavior and the high coefficients of determination for Power law and Herschel-Bulkley models (0.99) revealed the adequacy of these rheological models to describe flow behavior of mayonnaise.
The paper presents the results of examination some basic granulometric and hydraulic parameters such as changes in granulometry, velocity, shear stresses, Froude number, Reynolds number and flow resistance coefficient within the region of two different gravel bars in the mountain stream. The sediment samples were taken from points situated along the bars and from the riverbed in the area where the bars have their influence on the river regime. On the top of the granulometry and hydrodynamics survey there were also the chemical properties of the sediments, including heavy metals, examined. The main conclusion of the paper is that a point bar (developed on the river band) is less stable, than an up-of the obstruction bar (an alternate bar) developed along the river bank. Also there are number of observations connected with the hydrodynamics influence on stream bars formation. The study was undertaken on the Skawica-Jałowiecki Stream in the Polish part of the Carpathian Mountains.
This study examined the capacity of collateral dependent blood flow induced by a prolonged treadmill training program, as compared to a low collateral resistance model created by femoral artery to vein (A-V) shunt. Sprague-Dawley rats, with bilateral femoral artery occlusion were confined to cage activity (Sed, n=9) or trained by daily treadmill exercise (Tr, n=15; up to ~350 min/d) for 15 weeks. Another set of animals received a femoral A-V anastomosis in one limb and treated with (n=4) or without VEGF165 (n=9) infusion for 2 weeks. The contralateral side was used as control. Blood flow (BF) was measured with isotope labeled microspheres. Maximal calf muscle BF increased by 15 week training (up to 100±5.0 ml·min-1·100g-1 (p<0.05); 0.71±0.04 ml·min-1·100g-1·mmHg-1), a response better (20-25%) than the less demanding training programs used previously. In contrast, femoral A-V shunt with VEGF165 increased calf muscle conductance to 1.70±0.3 ml·min-1·100 g-1·mmHg-1 that is similar to blood flows observed in non-occluded rats during maximal running. Our data indicate that the collateral circuit development is related to the driving stimulus and that exercise training, does not provide a maximal stimulus for adaptation that is possible. Nonetheless, exercise training results in profound increases in exercise capacity associated with this enhanced collateral blood flow. Our results illustrate that vascular adaptations can be much greater when physiologically induced stimuli are enhanced at the time of therapeutic angiogenesis.
This article presents general rules of determining load carrying capacity of timber beams strengthened with FRP materials with accordance to the American Standard PCF-5100 with relevance to the European. In addition, the conclusions from the comparison of the theoretical load carrying capacity and deflections evaluated on basis of PCF-5100 and PCF-6046 with the results of the laboratory tests conducted on full-scale beams are presented.
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