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Background. The purpose is to investigate metal non-opaque foreign bodies of firearm origin. Materials and methods. Five cases of removing soft tissue foreign bodies of gunshot origin were investigated, when radiography of the limb soft tissues didn’t detect foreign bodies, but they were removed during the primary surgical wound debridement. X-ray of soft tissue gunshot wounds found no foreign bodies. To study radiographic density, foreign bodies were placed in a foam model with subsequent multislice computed tomography. For spectral analysis of metal foreign bodies, we used wavelengths unconventional for X-ray, which allowed to conduct X-ray fluorescence and X-ray structural studies. Results. Radiographic density of metal foreign bodies ranged from 989 to 2123 HU. Given the different thickness of foreign bodies, from 0.4 to 3.2 mm, the average was 1700 ± 189 HU. The foam had radiographic density of –969 HU with model dimensions of 200 × 100 × 50 mm. When examining samples of foreign bodies, it was found that they are deformed, have different thicknesses. One of the samples is light and smooth on one side, and dark and rough on the other. X-ray fluorescence results: composition on the light side (% by mass): Al — base, Mn — 0.8, Fe — 0.3, Zn — 0.1, Cr — 0.05, Ti — 0.2, corresponding to Al-Mn alloy. The dark side is an oxidized Al-Mn alloy. In the spectrum of the dark side of the sample, the Br-Kα line was detected, which indicates the participation of bromine compounds in the oxidation process. From the smooth side of the sample, the spectrum of this line is not determined. Conclusions. Non-opaque metal foreign bodies of gunshot origin are a rare phenomenon. Metal foreign bodies with low radiographic density are non-ferromagnetic, the use of modern magnetic surgical instruments will not be effective. Visualization of metal foreign bodies, which are not determined by radiography, is possible with the help of multislice computed tomography. The use of the wavelength of primary radiation, which is unconventional for X-ray spectral analysis, and original X-ray optical schemes allows for quantitative determination of the composition and structure of any metal foreign bodies.

Mathematical model is the basis for computer decision support system (DSS) connected with food security strategy, in which food irradiation is one of the methods used for elimination of substance with pathogens. Such system can support an organisation of many different activities in the area of food safety. It can be designed for a specific region, country, etc., and is addressed to State Sanitary Inspection offices. The paper demonstrates the capabilities of the system in modeling activities of sanitary inspection teams aimed at pathogen elimination with the use of electron beam irradiation in procedures of utilisation of animal originated food, related packaging, or other microbiologically contaminated materials. It describes new application of both computer supported decision systems and radiation processing. The elaborated mathematical models show human activities in the process of microbiological contamination elimination.

Measurements of W, the mean energy expended per ion pair formed, have been performed for 241Am alpha particles stopping in a number of the gases commonly used in ionisation chambers. Both absolute and relative measurements were made with nitrogen used as the reference gas for the relative measurements. The absolute method entailed a simultaneous measurement of a quantity of charge and the number of alpha particles which produced that charge, whilst the relative approach simply required a determination of the ratio of ion currents. Results were obtained for methane-based tissue-equivalent gas, for its constituents, i.e. methane, carbon dioxide and nitrogen, for argon, and also for a gas mixture with a composition approximately equivalent to A-150 plastic.

Values of W (the mean energy required to create an ion pair when a charged particle is stopped in a gas) are needed in radiation dosimetry to convert ionisation chamber current readings to absorbed dose. For neutron dosimetry the most important W values are those for protons, and this paper describes absolute measurements for protons with energies between 1.2 and 3.5 MeV for methane-based tissue-equivalent gas and its constituent gases, i.e. methane, carbon dioxide and nitrogen. An ionisation chamber with a parallel-plate arrangement was used to determine the integrated charge created by a measured number of protons, and W values were determined with an estimated uncertainty of about +/- 0.5%. The results are presented and compared with previous measurements. In general the present data tend to be somewhat lower than previously reported values. Finally the accuracy of a formula for predicting W values for gas mixtures from the values for the individual constituents is investigated.

The paper describes the properties of synchrotron radiation and makes some comparison with other X-ray sources. The use of synchrotron radiation for various types of X-ray imaging is discussed with reference to specific examples drawn from work carried out recently at the SERC Daresbury Laboratory.

The basis of a two-component neutron monitoring system that could be applied to both survey instruments and personal dosemeters is considered. Neutrons with energies below 10 keV are detected by a thermal neutron detector which, in the survey instrument, is located inside a small moderating sphere, whereas in the personal dosemeter it is positioned behind a thermal neutron shield located on an individual's body. Neutrons above 10 keV are detected by counting pulses produced by protons ejected from a thin hydrogenous foil. By judicious choice of the characteristics of the detection elements, it is possible to ensure that the sum of the sensitivities of the elements of both survey instrument and personal dosemeter vary with neutron energy in a way close to that required for radiological protection purposes throughout the range thermal-10 MeV. The realisation of the elements sensitive below 10 keV presents few fundamental problems and appropriate devices have been reported in the literature. Those sensitive above 10 keV have proved to be more difficult to realise in practice.