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Algae and cyanobacteria are capable living under harsh conditions in the natural environments and can develop peculiar survival processes. In order to evaluate radiation shielding properties of green algae; Chlorella vulgaris, Scenedesmus obliquus, and cyanobacteria; Synechococcus sp., Planktothrix limnetica, Microcystis aeruginosa, Arthrospira maxima, Anabaena affinis, Phormidium articulatum, and Pseudoanabaena sp. were cultured in batch systems. Air dried biomass was tested for its high tolerance to gamma-radiations in terms of linear attenuation coefficients. In the present work, the linear and mass attenuation coefficients were measured at photon energies of 1173 and 1332 keV. Protection capacity of some biomass was observed to be higher than a 1-cm thick lead standard for comparison. Gamma ray related protection depends not only to thickness but also to density (g/cm3). Hence the effect of biomass density also was tested and significantly found the tested biomass absorbed more of the incoming energy on a density basis than lead. This paper discusses the a new approach to environmental protection from gamma ray. The findings suggest that the test samples, especially cyanobacteria, have a potential for reducing gamma ray more significantly than lead and can be used as shielding materials.

Gamma ray attenuation coefficients of metal matrix composites have been investigated. For this purpose, the linear attenuation coefficients of composites containing boron carbide (BC) at different rates have been measured using a gamma spectrometer that contains a NaI(Tl) detector and MCA at 662, 1173 and 1332 keV, which are obtained from Cs and Co sources. The measured results were compared with the calculation obtained using computer code of XCOM for 1 keV-1 GeV gamma energies. [ABSTRACT FROM AUTHOR]

Highlights: [•] The γ and neutron shielding properties of different types of concretes have been investigated by Nxcom program. [•] All gamma ray attenuation parameters increase with increase marble content. [•] Fast neutron attenuation coefficient decreases with increase marble content. [•] Single-valued effective atomic numbers should be treated with some caution. [Copyright &y& Elsevier]

Abstract: The neutron and gamma-ray shielding properties of concrete containing different proportions of barite as an aggregate have been investigated. The macroscopic fast neutron removal cross-sections have been calculated and compared with the attenuation of gamma-rays with 8MeV photon energy, because for most shields the neutron produced at 8MeV are most likely to penetrate. The calculation of neutron removal cross-section has been done by using NXcom program and the photon linear attenuation coefficients were obtained via XCOM code. The best values of barite proportion and density of concrete for maximum shielding against both neutrons and gamma-rays have been determined graphically. The transmission of both gamma rays and neutrons has been obtained as a function of thickness of concrete for all concrete types. It was found that increasing barite proportion in the concrete increased the gamma attenuation coefficient while it decreased the neutron removal cross-section. [Copyright &y& Elsevier]

Abstract: The photon attenuation coefficients of concretes produced using pumice as an aggregate, have been measured at the photon energies of 662, 1173 and 1332keV to test the radiation shielding properties. The measured results have been compared with the calculation which has been done by using XCOM computer code. The obtained results have also been compared with the normal type of concrete in order to see the effect of pumice to radiation shielding properties. [Copyright &y& Elsevier]

Abstract: The activity concentrations of uranium, thorium and potassium can vary from material to material and it should be measured as the radiation is hazardous for human health. Thus first studies have been planned to obtain radioactivity of building material used in the Isparta region of Turkey. The radioactivity of some building materials used in this region has been measured using a γ-ray spectrometry, which contains a NaI(Tl) detector connected to MCA. The specific activity for 226Ra, 232Th and 40K, from the selected building materials, were in the range 17.91–58.88, 6.77–19.49 and 65.72–248.76Bq/kg, respectively. Absorbed dose rate in air (D), annual effective dose (AED), radium equivalent activities (Raeq), and external hazard index (H ex) associated with the natural radionuclide are calculated to assess the radiation hazard of the natural radioactivity in the building materials. It was found that none of the results exceeds the recommended limit value. [Copyright &y& Elsevier]

Radiation detection has been a main interest for researchers as all kind of produced particles in atomic and subatomic physics based on the measurement systems so-called detector. Detection efficiency is one of the main parameter in detection system besides many other different parameters of the detector. The absolute efficiency of the gamma detector system will be used at Turkish Accelerator and Radiation Laboratory at Ankara (TARLA) is simulated using MCNPX code (version 2.4.0). The MCNP is the general purpose MC code that can be used for neutron, photon, electron or coupled neutron, photon, electron transport. The results have been obtained for NaI(Tl) detector system and compared with the experimental results. A good agreement was found between calculation and experiment. [ABSTRACT FROM AUTHOR]

The cross section for (γ,N) reaction is important for investigation of nuclear structure, especially in low-energy giant dipole resonance (GDR). The total cross sections of 12C(γ,n)11C and 12C(γ,p)11B reactions, calculated using TALYS 1.2 nuclear code, are 15.5 to 40 MeV and 15 to 110 MeV, respectively. In the calculations, the default pre-equilibrium models and Brink-Axel Lorentzian model in all of the gamma strength functions have been used. The effects of the gamma strength function on the cross section exchange data has determined the most compatible model type. The results are compared with the experimental data from the EXFOR database and the evaluated nuclear data from TENDL-2012. Our calculated results are in good agreement with the previously reported experimental results. [ABSTRACT FROM AUTHOR]

Since the technology concerning gamma radiation showed a rapid development, it became a necessity to be protected from it. One of the common shielding materials for this purpose is concrete. This study aims to give the effect of pumice rate on the gamma radiation attenuation coefficients of normal concrete (p = 2:476 g cm-3) containing different rates of pumice mineral. Pumice, for which the Gölcük region in Isparta province is rich, is a volcanic originated spongy and porous mineral. Although it is a light material, it has a high comprehensive strength and heat resistance. So it became a common construction material in buildings. In the study, the variation of attenuation coefficients for concretes of different pumice rates were measured for 662, 1173 and 1332 keV photons using a NaI(Tl) detector. The experimental values were compared with the theoretical ones obtained by XCOM code. [ABSTRACT FROM AUTHOR]

The linear attenuation coefficients of different marble samples (Perlato Beige, Regal Beige and Crema Siva Beige) produced in Amasya were measured. The measurements have been performed at the photon energies of 511, 835 and 1274 keV which were obtained using 22Na and 54Mn sources. The measurements have been performed using a gamma spectrometer which contains 3″ × 3″ NaI(Tl) detector connected to 16384 channel Multi-Channel-Analyser (MCA). [ABSTRACT FROM AUTHOR]

After discovery of the radioactivity by Becquerel, radiation started to be used in large fields and it became part of our life nowadays. Using radiation from industry to medicine brings its hazardous effect and radiation protection developed in physics in parallel with the utilization of radiation. Although time, distance and shielding are the main rules to be protected from radiation, shielding is most effective way. In this case development of shielding materials becomes important. Clay is an interesting material and besides using it for different purposes it can be used as plaster material in building construction. In this study iron doped into clay samples and radiation shielding properties has been measured at 662 keV gamma rays. The measurements have been performed using gamma spectrometer system which contains NaI(Tl) and 16k multichannel analyser. [ABSTRACT FROM AUTHOR]

The fabrication of TePbMgX glass system has been done using the standard melt quenching method. The number of bonds per unit volume (n b) increases from 7.77 x 1022 cm−3 to 8.02 x 1022 cm−3. The values of E, K, G and L moduli decreases from 31.58 to 23.22 GPa for E, 14.79 to 11.76 GPa for K, 14.82 to 10.63 GPa for G and 34.55 to 25.93 GPa for L respectively as the PbO increases from 35 to 55%. The σ lies in the range of 0.145–0.172. The indirect and direct band gap energies decrease from 2.832 to 2.673 eV and 3.120–3.005 eV respectively with increasing mol% of the PbO. Moreover, with the help of FLUKA code, we reported the mass attenuation coefficient (μ/ρ) for the prepared samples between 0.122 and 1.458 MeV. The FLUKA results were compared with those generated from Phy-X software and a good agreement was reported and this validated the simulated μ/ρ results. The linear attenuation coefficient (LAC) was determined to examine the influence of adding PbO on the shielding performance of the prepared samples. The LAC result suggested that the attenuation performance for the TePbMgX glass systems is highly effective when exposed to low energy radiation, and, by contrast, the glasses become worse attenuators when exposed to high energy radiation. Also, the glass with 55 mol% of PbO (MgO free) has a higher LAC than the glasses with 35–50 mol% of PbO (5-20 mol% of MgO). The half value layer (HVL) of the glasses greatly increase with increasing energy. For TePbMg1, the HVL increases from 0.050 cm at 0.122 MeV, to 1.559 cm at 0.779 MeV, and 2.573 cm at 1.458 MeV. This HVL results demonstrated that increasing the PbO content in the glasses improves the shielding ability of the glass system, with TePbMg5 having the best HVL at all energies. At 0.3443 MeV, the effective atomic number (Z eff) values increase from 48.40 for 35 mol% PbO, to 49.87 for 40 mol% PbO, 51.28 for 45 mol% PbO, 52.62 for 50 mol% PbO, and 53.89 for 55 mol% PbO. We calculated the Relative reduction in transmission (RRT) and we found that at 0.245 MeV, the RTT values at 0.245 MeV have the following values: 17% and 81% for the samples with thickness of 0.25 and 2.25 cm respectively. • The fabrication of TePbMgX glasses has been done using the melt quenching method. • The n b increases from 7.77 x 1022 cm−3 to 8.02 x 1022 cm−3. • The indirect band gap energy decreases from 2.832 to 2.673 eV with adding PbO. • The glass with 55 mol% of PbO (MgO free) has a higher LAC than the other glasses. • The values of E, K, G and L moduli decreases as the PbO increases from 35 to 55%. [ABSTRACT FROM AUTHOR]