The paper presents the experimental results of turbulent flow over hydraulically smooth and rough beds. Experiments were conducted in a rectangular flume under the aspect ratio b/h = 2 (b = width of the channel 0.5 m, and h = flow depth 0.25 m) for both the bed conditions. For the hydraulically rough bed, the roughness was created by using 3/8″ commercially available angular crushed stone chips; whereas sand of a median diameter d50 = 1.9 mm was used as the bed material for hydraulically smooth bed. The three-dimensional velocity components were captured by using a Vectrino (an acoustic Doppler velocimeter). The study focuses mainly on the turbulent characteristics within the dip that were observed towards the sidewall (corner) of the channel where the maximum velocity occurs below the free-surface. It was also observed that the nondimensional Reynolds shear stress changes its sign from positive to negative within the dip. The quadrant plots for the turbulent bursting shows that the signs of all the bursting events change within the dip. Below the dip, the probability of the occurrence of sweeps and ejections are more than that of inward and outward interactions. On the other hand, within the dip, the probability of the occurrence of the outward and inward interactions is more than that of sweeps and ejections.
Salivary urea is studied as a non-invasive alternative for screening and monitoring of renal diseases. Its high variability prevents a wider clinical use. Animal experiments are needed to identify factors affecting this marker. The aim of this study was to describe the inter-individual variability of salivary urea in healthy mice, establish reference intervals, and analyse the effects of sex, age and body weight. Plasma and saliva samples were obtained from 37 male and 41 female healthy adult CD1 mice aged 13–69 weeks (body weight 22–51 g). The reference interval for salivary urea in heathy mice based on our results is 2.7–8.4 mmol/l (CV = 23 %). Multivariate analysis did not show any significant effect of age, sex, or body weight. In addition, salivary urea did not correlate with its plasma concentrations. The high variability of the promising salivary marker of kidney function in healthy mice requires further research before its use to diagnose or monitor renal failure in animal models of kidney diseases. Other potential confounders should be analysed, including intra-individual and pre-analytical variability. In addition, a normalization factor such as total salivary proteins or salivation rate is likely needed.
Experiments were carried out for n-channel CMOS technology. Electron concentration in the channel decreases linearly from the source to the drain contact. Diffusion current component is independent on the x-coordinate and it is equal to the drift current component for the low electric field. Lateral component of the electric field intensity is inhomogeneous in the channel and it has a minimum value near the source contact and increases with the distance from the source to the drain. It reaches maximum value near the drain electrode. and Článek se zabývá transportem nosičů náboje v kanálu tranzistoru typu MOSFET za předpokladu, že pohyblivost elektronů nezávisí na intenzitě podélného elektrického pole, určeného napětím na kolektoru a koncentrace elektronů v kanálu je exponenciální funkcí rozdílového napětí mezi elektrodou hradla a křemíkového substrátu. V tomto případě je celkový proud složen z proudu driftového a difuzního a je určen poměr mezi oběma složkami. Za těchto předpokladů je odvozeno rozdělení koncentrace nosičů a závislost napětí na poloze v kanálu.
A modification of the double-modulation fluorometer is described that allows measuring very dilute phytoplankton samples. The high sensitivity is achieved by increasing the sample volume and by collecting the fluorescence from the large volume by an integrating sphere. The sensitivity of the instrument increased approximately proportionally to the volume of the sample. A further improvement of the sensitivity was achieved by replacing the PIN photodiode of the earlier versions by a photomultiplier. The instrument was used to measure fluorescence induction, F0 and Fm parameters, and QA- reoxidation kinetics at concentrations at and below 100 pM chlorophyll. and N. Dijkman ... [et al.].
In vivo reflectance and fluorescence spectra from berry skins of a white (Riesling) and red (Cabernet Sauvignon) grapevine variety were measured during a ripening season with a new CMOS radiometer instrument. Classical reference measurements were also carried out for a sugar content of the berry juice [°Brix] and pigment contents (chlorophyll a and b, carotenoids, anthocyanins) from methanol extracts of the berry skin. We showed that the colours and the spectra analysed from them could be taken as an unambiguous indicator of grapevine ripening. Reflectance spectra, which were affected by the content of pigments (chlorophylls and anthocyanins), effects of surface (wax layers), and tissue structure (cell size) of the berries well correlated (R2 = 0.89) with the °Brix measurements of the berries. The fast data acquisition of both reflectance and fluorescence spectra in one sample with our radiometer instrument made it superior over the time-consuming, traditional, and mostly destructive chemical analysis used in
vine-growing management., M. Navrátil, C. Buschmann., and Obsahuje seznam literatury
For a connected graph G of order n > 3 and an ordering s : v1, v2, . . . , vn of the vertices of G, d(s) = n−1 ∑ i=1 d(vi , vi+1), where d(vi , vi+1) is the distance between vi and vi+1. The traceable number t(G) of G is defined by t(G) = min {d(s)} , where the minimum is taken over all sequences s of the elements of V (G). It is shown that if G is a nontrivial connected graph of order n such that l is the length of a longest path in G and p is the maximum size of a spanning linear forest in G, then 2n−2−p ≤ t(G) ≤ 2n−2−l and both these bounds are sharp. We establish a formula for the traceable number of every tree in terms of its order and diameter. It is shown that if G is a connected graph of order n ≥ 3, then t(G) ≤ 2n − 4. We present characterizations of connected graphs of order n having traceable number 2n − 4 or 2n − 5. The relationship between the traceable number and the Hamiltonian number (the minimum length of a closed spanning walk) of a connected graph is studied. The traceable number t(v) of a vertex v in a connected graph G is defined by t(v) = min{d(s)}, where the minimum is taken over all linear orderings s of the vertices of G whose first term is v. We establish a formula for the traceable number t(v) of a vertex v in a tree. The Hamiltonian-connected number hcon(G) of a connected graph G is defined by hcon(G) = ∑ v∈V (G) t(v). We establish sharp bounds for hcon(G) of a connected graph G in terms of its order.