The paper deals with the determination of the discharge coefficient, effective head and newly the limit head in the Kindsvater-Shen formula for the determination of a relatively small discharge of clear water using a thin-plate weir with a triangular notch. The determination of the discharge coefficient, effective head and limit head is based on extensive experimental research and is verified by previous measurements by other authors. The experimental research was characterised by a large range of notch angles (from 5.25° to 91.17°), weir heights (from 0.00 m to 0.20 m), and water temperatures (from 15 °C to 45 °C), as well as a focus on relatively small heads (from 0.02 m to 0.18 m), which is where the strengths of the Kindsvater-Shen formula stand out. The experimental research supplemented existing knowledge about the overflow occurring with small heads and small weir notch angles. The newly determined dependencies in the Kindsvater-Shen formula extended its applicability to weirs with small notch angles and newly enabled the determination of the limit head, which restricts its applicability in the determination of small discharges.
The effects of shoot girdling on stomatal conductance (gs), leaf photosynthesis (PN), concentrations of carbohydrates, nitrogen and chlorophyll (Chl) in leaves, areal leaf mass (ALM), the diameter and length of shoots, and bud abscission in pistachio were investigated. Girdling individual shoots at the base of the current year’s shoot (girdle I), separating inflorescent buds on the terminal current year’s shoot from the developing fruits on the previous year’s shoot, reduced inflorescent bud abscission by 70% in comparison to nongirdled controls. Girdle I significantly reduced concentrations of nitrogen in leaves but increased those of nonstructural carbohydrates particularly of starch. Shoot diameter increased by 13.1% and 26.4% at 33 and 81 days after girdling (DAG), respectively, compared to 1% and 3.4% in the control, respectively. Both the leaf dry mass/fresh mass ratio and ALM were increased significantly by girdle I from 12 DAG. The concentrations of Chl a, Chl b, Chl (a+b), as well as the ratio of Chl a/b, all decreased with girdle I. The greatest negative effect of girdle I was on gs and PN. PN was reduced by 55% of its initial value and was 44% less than in the control leaves at 10 DAG, and fell to approximately 30% that of the control from 21 DAG. In contrast, girdling at the base of one-year-old shoots (girdle II), thus not separating fruits from the inflorescent buds, did not significantly affect gs or PN. The effect of girdling on PN and the possible factors that are involved in the reduction of photosynthesis in pistachio are discussed., S. N. Vemmos, A. Papagiannopoulou, S. Coward., and Obsahuje bibliografii
A 2-stratified graph G is a graph whose vertex set has been partitioned into two subsets, called the strata or color classes of G. Two 2-stratified graphs G and H are isomorphic if there exists a color-preserving isomorphism ϕ from G to H. A 2-stratified graph G is said to be homogeneously embedded in a 2-stratified graph H if for every vertex x of G and every vertex y of H, where x and y are colored the same, there exists an induced 2-stratified subgraph H 0 of H containing y and a color-preserving isomorphism ϕ from G to H0 such that ϕ(x) = y. A 2-stratified graph F of minimum order in which G can be homogeneously embedded is called a frame of G and the order of F is called the framing number fr(G) of G. It is shown that every 2-stratified graph can be homogeneously embedded in some 2-stratified graph. For a graph G, a 2-stratified graph F of minimum order in which every 2-stratification of G can be homogeneously embedded is called a fence of G and the order of F is called the fencing number fe(G) of G. The fencing numbers of some well-known classes of graphs are determined. It is shown that if G is a vertex-transitive graph of order n that is not a complete graph then fe(G) = 2n.
The present article is focusing on Lévi-Straussian concept of „la torsion“ (the twist), which was for a long time fairly neglected by the structuralist criticism. The article consists in three parts. The first one is dedicated to the „torsion“ in the context of Claude Lévi-Strauss' works; the second part is trying to take into account different interpretations of the „twist" within the frame of Canonic Formula, and the third one raises the question about the meaning of the Lévi-Straussian twist, which emerges - in view of the present autor - as an exponent of cross-cultural horizon.
Optické frekvenční hřebeny z módově synchronizovaných femtosekundových laserů znamenají převrat v měření frekvence světla. V jediném kroku jsou schopny svázat optické frekvence s mikrovlnnými, a poskytují tak dlouho chybějící mechanismus pro optické atomové hodiny. Rozšířením hranic metrologie času a frekvence nám hřebeny umožňují provádět nové testy fundamentálních fyzikálních zákonů. Přesná porovnání optických rezonančních frekvencí atomárního vodíku a jiných atomů s mikrovlnnou frekvencí ceziových atomových hodin stanovují citlivé meze pro možné pomalé změny fundamentálních konstant. Generace vysokých optických harmonických rozšiřuje techniky měření optického hřebenu až do extrémní ultrafialové oblasti, a vstupuje na nová teritoria přesné laserové spektroskopie. Tím, že umožňuje ovládat elektrická pole ultrarychlých laserových impulsů, otevírá metoda frekvenčního hřebenu také cestu k attosekundové technice. V našich laboratořích ve Stanfordu a Garchingu byl vývoj nových přístrojů a technik pro přesnou laserovou spektroskopii dlouho motivován snahou docílit stále větší rozlišení a přesnost měření v optické spektroskopii jednoduchého atomu vodíku, což umožňuje unikátní konfrontaci mezi experimentem a fundamentální teorií. Ve své přednášce chci o těchto dobrodružstvích a vývoji techniky laserového hřebenu vyprávět ze své osobní perspektivy., Theodor W. Hänsch ; přeložil Ivan Gregora., and Obsahuje seznam literatury
Expanding the domain of majority rule is widely seen as desirable for the European Union. But the functioning of majority rule depends on preconditions that are seldom taken into account. The basic precondition is that overruled minorities accept majority decisions instead of exiting the voting unit. The specific problem of applying majority rule in the European Union is that overruled minorities at the European level are majorities at the nation-state level. By distinguishing between three dimensions of conflicts - content, time and space - the article analyses under what conditions it is possible to expect minorities to accept majority decisions, thus enabling the resolution of conflict by majority rule at the European level.