In the recombination process of Photosystem II (S(2)Q(A)(-)-->S(1)Q(A)) the limiting step is the electron transfer from the reduced primary acceptor pheophytin Ph(-) to the oxidized primary donor P(+) and the rate depends on the equilibrium constant between states S(2)PPhQ(A)(-) and S(1)P(+)Ph(-)Q(A). Accordingly, mutations that affect the midpoint potential of Ph or of P result in a modified r...

Experiments on co-doped CsI:Tl,Sm suggest that samarium electron traps scavenge electrons from thallium traps and that electrons subsequently released by samarium recombine non-radiatively with trapped holes, thus suppressing afterglow. These experiments support the inference that electrons tunnel freely between samarium ions and are trapped preferentially as substitutional Sm + near VKA(Tl + )...

introduction: orthogonal radial fields are those in which the central axes are perpendicular to each other. an example of these orthogonal fields is the set of craniospinal orthogonal fields that are used for radiotherapy of medulloblastoma. craniospinal radial fields consist of two parallel-opposed fields for brain exposure and one or two posterior spinal fields for spinal cord exposure. the m...

phase sensitive detector described here has two principal applications: a- to produce a d.c out put proportional to- the amplitude of an incoming a,c signal and indicate, by the outut polarity, the phase of the signal with respect to an internal reference. b- to detect the presence of a signal of known phase and frequency which would otherwise be lost in «background noise» and to measure its am...

in this paper a new algorithm is presented for coherent radar detection of targets, when distribution of the interference (clutter and noise) is non-gaussian. the neyman-pearson criterion is used for optimal detection and several successive received samples from a radar range cell are used for detection in the same cell. on the basis of recent empirical evidences, the interference distribution ...