Computed tomography (CT) dosimetry normally uses an ionization chamber 100 mm long to estimate the computed tomography dose index (CTDI), however some reports have already indicated that small devices could replace the long ion chamber to improve quality assurance procedures in CT dosimetry. This paper presents a novel dosimetry system based in a commercial phototransistor evaluated for CT dosi...

In this paper, we present the first measurements on thermoluminescence from isolated thylakoids to probe the recombination reactions of S 2 (or possibly $3) with Q ~ or QA, after bicarbonate depletion and its readdition. The effects of bicarbonate depletion on the S2Q ~ (or 8 3 0 ~ ) thermoluminescence band was (1) a 6 1 0 ° C shift to a higher temperature; (2) a reduction in its intensity upon...

Milk protein concentrate powder has found a wide application as a food ingredient. We investigated the effects of ionizing ')'-radiation at doses ranging from 2 to 20 kGy on electron spi n resonance and the rmoluminescence intensities in samples of milk protein concentrate powder with varying protein contents (36-73 %wt), containing addltional Fe ++ ions (12-910 ppm) and stored under different ...

A major breakthrough in our understanding of how plants oxidize water to molecular O(2) was the discovery by P. Joliot and co-workers that the O(2) yield per flash, in a series of light flashes, oscillates with a periodicity of 4. This led to the concept by B. Kok and co-workers that these reactions involve accumulation of four positive charges in independent "O(2)-evolving centers," which unde...

PSII activity was inhibited after Spirulina platensis cells were incubated with different salt concentrations (0-0.8 M NaCl) for 12 h. Flash-induced fluorescence kinetics showed that in the absence of DCMU, the half time of the fast and slow components decreased while that of the middle component increased considerably with increasing salt concentration. In the presence of DCMU, fluorescence re...

Thermoluminescence is a simple technique very useful for studying electron transfer reactions on photosystem II (standard thermoluminescence) or the level of lipid peroxidation in membranes (high temperature thermoluminescence) in photosynthetic organisms. Both techniques were used to investigate the effects produced on Chlorella vulgaris cells by six compounds: the chemical intermediates bromo...

Thermoluminescence (TL) and photoluminescence (PL) properties of the Gd3+ doped lanthanum zirconium phosphor (La2Zr2O7:Gd3+) are reported in this work. La2Zr2O7 (LZO) has been p...

The Technical Report Series 398 (TRS-398), Electron Dosimetry Working Party (EWDP), and Task Group 51 (TG 51) are the most important protocols for reference dosimetry. In case of electron beam dosimetry, these recommend using parallel-plate ionization chambers beams with R50 values below specific thresholds. However, recent papers suggested cylindrical dosimetry all energies. Here we compared d...

thermoluminecsence (tl) characteristics of pure caso4 nanoparticles produced by co-precipitation method are presented. the formation of the nanoparticles was confirmed by x-ray diffraction (xrd) and scanning electron microscope (sem). tl glow curve of this phosphor, exposed to gamma radiation exhibits five overlapping glow peaks in the complex glow curve at 463, 470, 483, 498 and521(k) respecti...