ABSTRACT
A cyclic electron accelerator Microtron MT-25 will be installed in Havana, Cuba. Electrons, neutrons and gamma radiation up to 25 MeV can be produced in the MT-25. A detailed shielding analysis for the bunker is carried out using two ways: the NCRP-51 Report and the Monte Carlo Method (MCNP-4C Code). The walls and ceiling thicknesses are estimated with dose constraints of 0.5 and 20 mSv y(-1), respectively, and an area occupancy factor of 1/16. Both results are compared and a preliminary bunker design is shown.
Subject(s)
Electrons , Radiation Protection , Gamma Rays , Monte Carlo Method , Neutrons , Particle Accelerators , Phantoms, Imaging , Photons , Protective Devices , Radiation Dosage , Radiometry , Radiotherapy, High-Energy , X-RaysABSTRACT
In the seawater of the Atlantic Ocean and surface waters of different points of the World Ocean, including arctic basins and equatorial regions, microvibrion-predators of bacterial cells have been discovered. The number of microvibrions in the surface waters of the English Channel reaches a thousand cells per ml, but it varies, depending on the season. In this article a method of the separation and culture of microvibrions is described. The ultrastructure of two strains of microvibrions was investigated and a similarity found between their structure and Gram-negative bacteria. The distinctive features of microvibrions are their sea derivation and the ability to reproduce only in the presence of bacteria, without penetrating bacterial cells. To a certain extent, the antibacterial activity of seawater is connected with the presence in it of microvibrions.
