a Health Radiation Research Department, National Centre for Radiation Research and Technology, Atomic Energy Authority, Cairo, Egypt b Radiation Biology Department, National Centre for Radiation Research and Technology, Atomic Energy Authority, Cairo, Egypt c Department of Immunology, Medical Research Institute, Alexandria University, Alexandria, Egypt d Department of Surgery, Medical Research ...

background: humans beings are continuously exposed to ionizing radiation from natural sources. the main contributors to natural radiation are high-energy cosmic radiation and radioactive nuclides that originates in the earth’s crust. exposure to high levels of radiation can cause serious health effects. in this study an attempt has been made to monitor the levels of environmental background rad...

using photovoltaic systems is gradually expanded by increasing energy demand. abundance and availability of this energy, has turned to one of the most important sources of renewable energy. unfortunately, photovoltaic systems have two big problems: first, those have very low energy conversion efficiency (in act between 12 and 42 percent under certain circumstances). second, the power produced b...

passive solar systems such as solar chimneys need solar radiation in order to work. therefore, they cannot present stable natural ventilation when solar energy vanishes: to have a more robust and stable condition, solar energy should be stored during the day and released back during the night. phase change materials can save additional thermal energy during the day and release it during the nig...

This paper presents so-called radiation effectiveness factors that are intended to represent the biological effectiveness of different radiation types, relative to high-energy Co gamma rays, for the purpose of estimating cancer risks and probability of causation of radiogenic cancers in identified individuals. Radiation effectiveness factors are expressed as subjective probability distributions...

Radiation effects in silicon detectors are discussed in view of their application in future high-energy physics experiments. An overview is given of the major changes in the operational parameters due to radiation damage and their origin in the radiation-induced microscopic disorder in the silicon bulk. The principal radiation hardening technologies are described that have been adopted by the h...

The origin of the particles in the highest energy end of the cosmic ray spectrum is discussed in the context of the wider problem of the origin of the whole cosmic radiation as observed at the Earth. In particular we focus our attention on the acceleration problem and on the transition from galactic to extragalactic cosmic rays.