The role of cations in excitation energy distribution between the two photosystems of photosynthesis is well established. This paper provides evidence, for the first time, for an important role of anions in the regulation of distribution of absorbed light energy between the two photosystems. Inorganic anions caused redistribution of energy more in favour of photosystem I, as judged from measure...

We present an analysis of the X-ray properties of sources detected in the 13H XMM-Newton deep (200ks) field. In order to constrain the absorbed AGN population, we use extensive Monte Carlo simulations to directly compare the X-ray colours of observed sources with those predicted by several model distributions. In particular, we have carried out our comparisons over the entire 0.2–10 keV energy ...

animals that breed in ground holes can be exposed to higher doses of radiation from natural radioactive isotopes, including radon and its daughters, present in soil air. one of such species is the sand martin riparia riparia. examination of natural burrows in sand mines revealed radon levels of 2.82-1320 bq/m3 in the examined soil horizon where martins dug their burrows. it was shown that adult...

background: changes in body composition may be used for monitoring progression/ regression of a disease. prompt γ-rays in vivo neutron activation analysis (ivnaa) has been widely used for the measurement of body composition in recent years. objective: in this paper, we tried to improve the safety of ivnaa operator. methods: the most important factor for reducing the operator receiving dose is t...

The blue-green alga, Anacystis nidulans, was grown in lights of different colors and intensities, and its absorption and fluorescence properties were studied. Strong orange light, absorbed mainly by phycocyanin, causes reduction in the ratio of phycocyanin to chlorophyll a; strong red light, absorbed mainly by chlorophyll, causes an increase in this ratio. This confirms the earlier findings of ...

Introduction: In brachytherapy treatments, high-dose sources are used in interstitial placement. In this paper, the modeling of a common breast cancer treatment applicator called MammoSite is done by the Monte Carlo simulation code. Then, to study and calculate the amount of doses in the breast and the dose rate of the organs at risk of radiation, including: lungs, ribs and ski...

introduction in computed tomography (ct) technology, an optimal radiation dose can be achieved via changing radiation parameters such as ma, pitch factor, rotation time and tube voltage (kvp) for diagnostic images. materials and methods in this study, the brain, abdomen, and thorax scaning was performed using toshiba 16-slice scannerand standard aapm and ctdi phantoms. aapm phantom was used for...

large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. therefore, radiation unwanted dose is created in kidney. as a result, exact calculation of prescribed radiopharmaceuticals amount is important. monte carlo method is used for simulation of radiation transport in body due to random nature of radiation. in this research, for the first time...

large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. therefore, radiation unwanted dose is created in kidney. as a result, exact calculation of prescribed radiopharmaceuticals amount is important. monte carlo method is used for simulation of radiation transport in body due to random nature of radiation. in this research, for the first time...