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...

background: accelerated partial breast irradiation via interstitial balloon brachytherapy is a fast and effective treatment method for certain early stage breast cancers however skin, chest wall and lung doses are correlated with toxicity in patients treated with breast brachytherapy. objective: to investigate the percentage of the dose received by critical organ (skin), thermoluminescence dete...

Low-energy collisions of atomic ions and cluster ions with rare gas covered metal substrates can lead to strong light emission which is element and size specific. Instead of a direct energy transfer into the electronic system of the cluster the observed emission originates from excitons trapped in the rare gas layer which carries the excitation energy. The nature of the processes involved in th...

Low-temperature thermoluminescence has been used in attempt to understand the particular structure of ultra high dilutions. Samples are activated by irradiation after freezing at the temperature of liquid nitrogen (77 degrees K). Experimental results show that, in the course of rewarming, the thermoluminescent glow is susbtantially different between dilutions of different substances. It is sugg...