This contribution is a practical guide to the measurement of the different chlorophyll (Chl) fluorescence parameters and gives examples of their development under high-irradiance stress. From the Chl fluorescence induction kinetics upon irradiation of dark-adapted leaves, measured with the PAM fluorometer, various Chl fluorescence parameters, ratios, and quenching coefficients can be determined, which provide information on the functionality of the photosystem 2 (PS2) and the photosynthetic apparatus. These are the parameters Fv, Fm, F0, Fm', Fv', NF, and ΔF, the Chl fluorescence ratios Fv/Fm, Fv/F0, ΔF/Fm', as well as the photochemical (qP) and non-photochemical quenching coefficients (qN, qCN, and NPQ). qN consists of three components (qN = qE + qT + qI), the contribution of which can be determined via Chl fluorescence relaxation kinetics measured in the dark period after the induction kinetics. The above Chl fluorescence parameters and ratios, many of which are measured in the dark-adapted state of leaves, primarily provide information on the functionality of PS2. In fully developed green and dark-green leaves these Chl fluorescence parameters, measured at the upper adaxial leaf side, only reflect the Chl fluorescence of a small portion of the leaf chloroplasts of the green palisade parenchyma cells at the upper outer leaf half. Thus, PAM fluorometer measurements have to be performed at both leaf sides to obtain information on all chloroplasts of the whole leaf. Combined high irradiance (HI) and heat stress, applied at the upper leaf side, strongly reduced the quantum yield of the photochemical energy conversion at the upper leaf half to nearly zero, whereas the Chl fluorescence signals measured at the lower leaf side were not or only little affected. During this HL-stress treatment, qN, qCN, and NPQ increased in both leaf sides, but to a much higher extent at the lower compared to the upper leaf side. qN was the best indicator for non-photochemical quenching even during a stronger HL-stress, whereas qCN and NPQ decreased with progressive stress even though non-photochemical quenching still continued. It is strongly recommended to determine, in addition to the classical fluorescence parameters, via the PAM fluorometer also the Chl fluorescence decrease ratio RFd (Fd/Fs), which, when measured at saturation irradiance is directly correlated to the net CO2 assimilation rate (PN) of leaves. This RFd-ratio can be determined from the Chl fluorescence induction kinetics measured with the PAM fluorometer using continuous saturating light (cSL) during 4-5 min. As the RFd-values are fast measurable indicators correlating with the photosynthetic, activity of whole leaves, they should always be determined via the PAM fluorometer parallel to the other Chl fluorescence coefficients and ratios., and H. K. Lichtenthaler, C. Buschmann, M. Knapp.
This contribution deals with the modern finite volume schemes solving the Euler and Navier-Stokes equations for transonic flow problems. We will mention the TVD theory for first order schemes and some numerical examples obtained by 2D central and upwind schemes for 2D transonic flows in the GAMM channel or through the SE 1050 turbine of Škoda Plzeň. The TVD MacCormack method is extended to a 3D method for solving flows through turbine cascades. Numerical examples of unsteady transonic viscous (laminar) flows through the DCA 8% cascade are also presented for Re = 4600. Next, a new finite volume implicit scheme is presented for the case of unstructured meshes (with both triangular and quadrilateral cells) and inviscid compressible flows through the GAMM channel as well as the SE 1050 turbine cascade.
For an ordered set W = {w1, w2, . . . , wk} of vertices in a connected graph G and a vertex v of G, the code of v with respect to W is the k-vector cW (v) = (d(v, w1), d(v, w2), . . . , d(v, wk)). The set W is an independent resolving set for G if (1) W is independent in G and (2) distinct vertices have distinct codes with respect to W. The cardinality of a minimum independent resolving set in G is the independent resolving number ir(G). We study the existence of independent resolving sets in graphs, characterize all nontrivial connected graphs G of order n with ir(G) = 1, n − 1, n − 2, and present several realization results. It is shown that for every pair r, k of integers with k ≥ 2 and 0 ≤ r ≤ k, there exists a connected graph G with ir(G) = k such that exactly r vertices belong to every minimum independent resolving set of G.