No abstract available

[en] This nomenclature is intended to give accurate descriptions of some common or important naturally occurring and synthetic constituents of aggregates for radiation-shielding concrete, that, at the same time, are not common or important constituents of concrete aggregates in general use. While most of the minerals and rocks discussed below may occur in small quantities in aggregates in general use, they are not major constituents of such aggregates. Common constituents of aggregates in general use are described in ASTM Descriptive Nomenclature C 294, Constituents of Natural Mineral Aggregates. Radiation-shielding concrete often contains such aggregates but other special aggregates are used in some circumstances. The synthetic aggregates included are ferrophosphorus and boron frits. The descriptions are not adequate to permit the identification of materials, since accurate identification of natural and synthetic aggregate constituents in many cases can only be made by a qualified geologist, mineralogist, or petrographer, using the apparatus and procedures of these sciences

[en] Small volumes with lead brick and lead glass shielding are used, and in nuclear technology we call them ''hot cell''. Furthermore for separating the exposure rooms from the operator rooms lead glassed windows of heavy concreate walls can be used. Unfortunately, these glasses can not be produced in Turkey. ordinary crystals which have lead-oxide in them, can be produced in Turkey, in this essay we have investigated the usage of ordinary crystals for the radiation shielding. Crystals have been tested with different types of radiation and ''radiation absorbtion'' curves, ''half thickness'' and ''tenth value thickness'' have been calculated. (author)

[en] The coexistence of Al and Si has a significant impact on the electromagnetic shielding effectiveness (SE) of Ti₃(Al, Si)C₂ ceramics and the total SE (SE_T) peaked when mol(Al): mol(Si) = 1:1. Ti₃(Al_1/2Si_1/2)C₂ ceramic exhibit high SE_T around 47 dB and excellent frequency-stability within X-band frequency. The high SE_T originates from both high reflection and absorption. High reflection is related to the larger amounts of defects, while high absorption was ascribed to the higher Ohimic loss and coarse microstructure which is beneficial for multiple reflections. Results indicate that Ti₃(Al_1/2Si_1/2)C₂ ceramic could be considered as promising structural electromagnetic shielding materials.

[en] Half value layer (radiation energy) of 90deg scattered radiation shielding materials was measured at 1 m distance from the central ray of the primary beam. Scattered radiation was measured from 100 to 200 kVp for 0-2.0mm Cu+1.0mm Al added filter in the primary beam for a deep therapeutic unit, the obtained result results were as follows: 1. The ratio of scattered radiation to primary radiation was increased by the using lighter filter. 2. The ratio of scattered radiation to primary radiation was decreased by using heavier filter. 3. The ratio of scattered radiation to primary radiation was independent of tube voltage. 4. The scattered radiation of high energy was produced, when the effective atomic number and density of shielding material were high. (Author)

[en] The invention aims to propose a concrete additive which, alone, brings together a high density property able to stop the gamma radiations, combined with a large cross section, able to capture the thermal neutrons. With this in view, the first object of the invention is the application of granular cast iron containing around 0.1 to 5% boron by weight. Its further object is the fabrication of this granular material, characterized by a preparation in the cupola furnace into which is injected a boron compound, preferably ore containing boron

[en] Sulfur coated colemanite particles were used as coarse aggregate in concrete. It was found that the boron content of concrete could be increased to a value about four times larger than those reached in the past. As the amount of sulfur coated colemanite increases in the concrete, the density and the compressive strength decrease, but the total water content increases. The fast neutron flux slowly decreases with the increased colemanite, while the thermal flux is lowered in great extent. The total radiation dose is not considerably increased even though the colemanite content is increased twice that of the ones used in the past. (author)

[en] Baritosiderite with a minimal content of 40% of barite is used as aggregate for concrete. The specific weight of the baritosiderite is minimally 3.70 g/cm³. The corrective component for increasing bulk density of heavy concrete is cast iron grit and steel fragments. Other used components are water, cement and plasticizers. (J.B.)

[en] Published in summary form only

No abstract available