For the purposes of planning the protection against and control of water pollution in streams, on the basis of theoretic and numeric analyses of the problem, a methodology has been worked out for defining incidental pollution spread in open streams, which is generally applicable to non-stationary releases and spread of pollution in a stream. It covers the problem of longitudinal dispersion in natural streams in its totality. Attention has been paid to dissoluble or suspended non-depositable polluting substances. Presented are the required field, laboratory and numeric investigations. By the basic program DISPER a numeric model has been developed and the program INCH) made. The programs for calculation of dispersion coefficient have been made and successfully applied: D (commonly measured values of the flow) and RUTINGD (data on the stream tracing). The programs had been previously checked, assuming simple calculation cases and using the existing data on tracing in the river Miljacka. For further checking and applicability of the methodology, measuring data have been used, obtained for a selected stretch of the river Vrbas for a length of 31,897m. For prediction of possible incidental pollution spreading, assumed was an unpredicted release of a constant quantity of untreated waste cyanide water during 1600s. On the basis of the data from one tracing reach of the river Vrbas, it has been shown that by numeric calculation it is possible to obtain excellent concordance of the measured and numeric curve. Therefore, it is necessary to use corresponding hydraulic-hydrologic data, and importantly, to define reliable values of dispersion coefficients.
Sufficient conditions are given in order that a sequence of linear operators Ln(Λ, ·) defined by Ln(Λ, f) := n ∑ k=0 λnkf(k)χk (n ∈ N0), f(k) := ∫ G fχk (k ∈ N0), converges in Lnorm to identity, where f ∈ L(G), q ∈ [1,∞], λn0 = 1 (∀n ∈ N0), λnk = 0 (∀k > n, ∀n ∈ N0) and G is a general Vilenkin group. In case of bounded Vilenkin groups, our result coincides with an earlier result of Blyumin.
We address high-order harmonic generation with linearly polarized bichromatic fields, concentrating on a modulation in the harmonic yield as a function of the relative phase between the two field components, and on an offset phase shift of this modulation for neighboring cutoff harmonics. These effects have been recently observed in experiments where the relative phase between the two driving fields was controlled. Using the
Both excitatory and inhibitory intrinsic neurons could be found within the gastric wall, both of them receiving innervation from vagal fibres and being sensitive to nicotine. The effects of three nicotine receptor agonists, nicotine, tetramethylammonium (TMA) and 1,1-dimethyl-4-phenylpiperazinium (DMPP), on contractile activity of preparations isolated from feline and human gastric corpus wall were investigated. While DMPP (3.5x10(-8) to 5.9x10(-4)m) did not affect either spontaneous contractions or basal tension of isolated preparations from both species, TMA produced concentration-dependent tonic contractions of both circular and longitudinal isolated preparations from human (3.66x10(-5) to 5.10x10(-3)m) and feline (6. 1x10(-7) to 2.1x10(-3)m) stomach. On the other hand, nicotine (4. 1x10(-8) to 7.0x10(-4)m) produced concentration-dependent relaxation of only circular isolated preparations from feline gastric corpus. The effect of nicotine was sensitive to mecamylamine, and not to pancuronium, while the effect of TMA was sensitive to both mecamylamine and pancuronium. Although in our experiments DMPP had no effect, its excitatory action on gastric intrinsic neurons through the hexamethonium-insensitive pathway had already been described. The results of our study suggest that two different types of ganglion nicotine receptor exist together within the wall of feline stomach: (1) type N(N1)which is involved in relaxation and is sensitive only to nicotine and mecamylamine, and not to DMPP, TMA and pancuronium; (2) and type N(N2)which is involved in contraction of gastric muscle and sensitive to DMPP, TMA, mecamylamine and pancuronium, and not to nicotine.
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