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In a medical linear accelerator, the primary and secondary collimators are generally made of high atomic weight metals. The energy of the x-rays generated by accelerated electrons exceeds the bonding energies of high atomic number materials such as tungsten, and lead in the structure of the components in the accelerator head, it causes the production of neutron from the nucleus. Consequently, the resulting photo-neutrons can easily be scattered and spread into the treatment room. Thus, an additional neutron dose cannot be ignored in the tumor volume of the patient and in areas outside this volume. The contribution of the primary and secondary collimators to the neutron contamination is found to be approximately 52% and 30%, respectively. In this paper, the effects of using different composite materials such as Boron, Cadmium, and Polyethylene in secondary collimators on neutron contamination have been investigated by using Fluka Monte Carlo and TALYS 1.9 codes

In a medical linear accelerator, the primary and secondary collimators are generally made of high atomic weight metals. The energy of the x-rays generated by accelerated electrons exceeds the bonding energies of high atomic number materials such as tungsten, and lead in the structure of the components in the accelerator head, it causes the production of neutron from the nucleus. Consequently, the resulting photo-neutrons can easily be scattered and spread into the treatment room. Thus, an additional neutron dose cannot be ignored in the tumor volume of the patient and in areas outside this volume. The contribution of the primary and secondary collimators to the neutron contamination is found to be approximately 52% and 30%, respectively. In this paper, the effects of using different composite materials such as Boron, Cadmium, and Polyethylene in secondary collimators on neutron contamination have been investigated by using Fluka Monte Carlo and TALYS 1.9 codes

This preliminary study reveals that basaltic tephra(pumice) is a material suitable for the production of high quality ceramics and also provides important evidence concerning the transfer of the process of manufacture from the laboratory to commercial production. Specifically, the shapes of pores and the uniformity of the pore size frequency distributions in the basaltic ceramic preparations are the major textural properties controlling compressive strength, whereas the contents and textures of fibrous minerals occupying the pores appear to be less significant in determining the physical properties of these ceramics.

Agenesis of the right lobe of the liver is an extremely rare congenital anomaly, usually accompanied by additional anomalies such as a retrohepatically or suprahepatically located gallbladder. in this report we present a new case of agenesis of the right lobe of the liver with the Chiliaditi syndrome and a subdiaphragmatic hydatid cyst, diagnosed by CT and CT-cholangiography