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The current work discusses the radiation attenuation capability and different shielding characteristics of different mortar samples. The samples were prepared by replacing different percentages of fine aggregate with iron filling and replacing different percentages of hydrated lime with Bi 2 O 3 (0-50 wt.%). The prepared mortar samples are coded as CHBFX where X = 0, 10, 30, and 50 wt.%. The mass and linear attenuation coefficient was determined experimentally using a narrow beam technique, where a high purity germanium detector, and different point gamma-ray sources (such as Am-241, Cs-137, and Co-60). The linear attenuation coefficient was also calculated using the Monte-Carlo simulation code and the online Phy-X/PSD software. The comparison of the three methods showed a good agreement in the results. The linear attenuation coefficient drops from 19.821 to 0.053 cm -1 for CHBF0, from 27.496 to 0.057 cm -1 for CHBF10, from 42.351 to 0.064 cm -1 for CHBF30, and from 55.068 to 0.071 cm -1 for CHBF50 at photon energy range from 0.015 to 15 MeV. The half-value layer thickness, tenth-value layer thickness, and mean free path of the prepared mortar composites were also calculated photon energy ranged from 0.015 to 15 MeV. The fast neutron removal cross-section of the prepared CHBFX mortar samples have values of 0.096 cm -1 , 0.098 cm -1 , 0.103 cm -1 , and 0.107 cm -1 for the mortar samples CHBF0, CHBF10, CHBF30, and CHBF50, respectively. The results showed that the mortar sample with the highest iron filing concentration, CHBF50, provides the best protection against gamma rays and fast neutrons which could be used in the nuclear and medical fields., (© 2024. The Author(s).)

With the use of multilayer materials such as concrete, mortar and ceramics that were fortified with PbO, WO 3 and Bi 2 O 3 nanoparticles, our study's objective was to produce a an effective photon shielding system. Experimental evaluation of the radiation shielding efficiency of two sets of samples with various thicknesses was conducted. The elemental content and morphology of the samples were corroborated by SEM and EDX studies, with ceramic samples exhibiting superior particle distribution and fewer voids than concrete and mortar specimens. The linear attenuation coefficient (LAC) was studied both experimentally and numerically using the Phy-X program, and it was found that the two sets of values were in satisfactory agreement. The values of LAC were consistently greater for samples with 30% of the selected heavy metal oxides than for those with 10%. The LAC for Cer-1 was 5.003 cm -1 at 0.059 MeV, whereas the corresponding LAC for Cer-2 was 2.123 cm -1 . The LAC values were as follows: ceramics (5.003 cm -1 ), mortar (2.999 cm -1 ), concrete (2.733 cm -1 ), and the transmission factor (TF) examination of the multiple-layer specimens showed that the TF of the 3 cm thick multilayer sample was lower than that of the 2 cm thick sample and that both multilayer samples displayed better attenuation efficiency in comparison to single-layer specimens. The results show the possibility for employing multilayer structures with different densities, thicknesses, and sizes in suitable radiation shielding applications., (© 2023. The Author(s).)

This study aims to investigate the impact of CeO 2 content and particle size on the radiation shielding abilities of polydimethylsiloxane, also known as silicon rubber (SR). We prepared different SR samples with 10, 30, and 50% of micro and nano CeO 2 and we measured the linear attenuation coefficient (LAC) for these samples. We found that the LAC of the SR increases by increasing the CeO 2 and all prepared SR samples had higher LACs than the pure SR. We examined the effect of the size of the particles on the LAC and the results demonstrated that the LAC for nano CeO 2 is higher than that of micro CeO 2 . We investigated the half value layer (HVL) for the prepared SR samples and the results revealed that the SR with 10% micro CeO 2 had a greater HVL than the SR with 10% nano CeO 2 . The HVL results demonstrated that the SR containing nanoparticles had higher attenuation effectiveness than the SR with micro CeO 2 . We also prepared SR samples containing CeO 2 in both sizes (i.e., micro and nano) and we found that the HVL of the SR containing both sizes was lower than the HVL of the SR with nano CeO 2 . The radiation protection efficiency (RPE) at 0.059 MeV for the SR with 10% micro and nano CeO 2 was 94.2 and 95.6%, respectively, while the RPE of SR containing both sizes (5% micro CeO 2 + 5% micro CeO 2 ) was 96.1% at the same energy. The RPE results also indicated that the attenuation ability was improved when utilizing the micro and nano CeO 2 as opposed to the micro CeO 2 or nano CeO 2 at 0.662, 1.173, and 1.333 MeV.

We developed new composites for photons shielding applications. The composite were prepared with epoxy resin, red clay and bismuth oxide nanoparticles (Bi 2 O 3 NPs). In order to establish which ratio of red clay to Bi 2 O 3 NPs provides the best shielding capabilities, several different ratios of red clay to Bi 2 O 3 NPs were tested. The transmission factor (TF) was calculated for two different thicknesses of each sample. From the TF data, we found that epoxy resin materials have a high attenuation capacity at low energy. For ERB-10 sample (40%Epoxy + 50% Red clay + 10% Bi 2 O 3 NPs), the TF values are 52.3% and 14.3% for thicknesses of 0.5 and 1.5 cm (at 0.06 MeV). The composite which contains the maximum amount of Bi 2 O 3 nanoparticles (40%Epoxy + 50% Red clay + 10% Bi 2 O 3 NPs, coded as ERB-30) has lower TF than the other composites. The TF data demonstrated that ERB-30 is capable of producing more effective attenuation from gamma rays. We also determined the linear attenuation coefficient (LAC) for the prepared composites and we found that the LAC increases for a given energy in proportion to the Bi 2 O 3 NPs ratio. For the ERB-0 (free Bi 2 O 3 NPs), the LAC at 0.662 MeV is 0.143 cm -1 , and it increases to 0.805 cm -1 when 10% of Bi 2 O 3 NPs is added to the epoxy resin composite. The half value layer (HVL) results showed that the thickness necessary to shield that photons to its half intensity can be significantly lowered by increasing the weight fraction of the Bi 2 O 3 NPs in the epoxy resin composite from 0 to 30%. The HVL for ERB-20 and ERB-30 were compared with other materials such as (Epoxy as a matrix material and Al 2 O 3 , Fe 2 O 3 , MgO and ZrO 2 as filler oxides in the matrix at 0.662 MeV. The HVL values for ERB-20 and ERB-30 are 4.385 and 3.988 cm and this is lower than all the selected epoxy polymers., (© 2023. The Author(s).)

Background: Cardiovascular magnetic resonance (CMR) imaging is an important modality that allows the assessment of regional myocardial function by measuring myocardial deformation parameters, such as strain and strain rate throughout the cardiac cycle. Feature tracking is a promising quantitative post-processing technique that is increasingly used. It is commonly applied to cine images, in particular steady-state free precession, acquired during routine CMR examinations., Objective: To review the studies that have used feature tracking techniques in healthy subjects or patients with cardiovascular diseases. The article emphasizes the advantages and limitations of feature tracking when applied to regional deformation parameters. The challenges of applying the techniques in clinics and potential solutions are also reviewed., Results: Research studies in healthy volunteers and/or patients either applied CMR-feature tracking alone to assess myocardial motion or compared it with either established CMR-tagging techniques or to speckle tracking echocardiography. These studies assessed the feasibility and reliability of calculating or determining global and regional myocardial deformation strain parameters. Regional deformation parameters are reviewed and compared. Better reproducibility for global deformation was observed compared with segmental parameters. Overall, studies demonstrated that circumferential was the most reproducible deformation parameter, usually followed by longitudinal strain; in contrast, radial strain showed high variability., Conclusion: Although feature tracking is a promising tool, there are still discrepancies in the results obtained using different software packages. This highlights a clear need for standardization of MRI acquisition parameters and feature tracking analysis methodologies. Validation, including physical and numerical phantoms, is still required to facilitate the use of feature tracking in routine clinical practice.