Radiation Protection Applications Research Articles

Computed tomography imaging analysis of a fused filament fabrication (FFF) 3D printed neck-thyroid phantom for multidisciplinary purposes

The application of the 3D printing technique for the development of low-cost phantoms is being investigated recently and requires a complex study of the interaction of printed materials with different types and qualities of radiation, as well as the characterization of printing filaments to correctly simulate human tissue attenuation. This study aims to present the Computed Tomography (CT) Imaging analysis of a fused filament fabrication (FFF) 3D printed anthropomorphic neck-thyroid phantom. The commercial phantom ATOM MAX 711 from CIRS was used as anatomy of reference for the 3D modeling base of the neck-thyroid phantom. Commercially available PLA and ABS XCT-A validated at IPEN were used in the 3D printing process in order to simulate soft and bone tissues respectively. The printing process was done using the RAISE3D PRO 2 FFF printer from IPEN. The imaging study of the phantom was performed through the analysis of images from a CT acquisition, comparing the Hounsfield Units (HU) numbers of the tissues between both CIRS and 3D printed phantoms. The developed phantom is a feasible alternative and presents some desirable characteristics for applications in radiation protection, measurements of radioisotopes incorporated in the thyroid (both contamination counters and nuclear medicine detectors) and training of techniques of acquisition of images with X rays.

Significance of multicomponent modifiers incited Dy3+ ions doped boro-phosphate glasses for radiation shielding applications

Dy3+ doped boro-phosphate glasses [BPXNfDy1.0] were synthesized with the chemical composition 44B2O3+25P2O5+15NaF+15MO+1Dy2O3 (where M=Li2CO3, Mg2CO3, Sr2CO3, ZnO and Ba2CO3) by conventional melt-quenching method. The physical properties (density, refractive index), structural (boron-boron separation, phosphorous-phosphorous separation), FTIR (functional groups) and absorption properties (direct and indirect bandgap) were explored in examining the ability of the proposed multicomponent glasses for radiation protection applications. The XRD pattern declared the non-periodicity/amorphous nature of the sample. The Ba-containing glass is observed to possess a tightly packed nature among the present glass samples, which is confirmed from the evaluation of the structural parameters such as dB−B, dP−P. The molar volume (Vm), and oxygen packing density (OPD) of the Ba-incorporated glass possess reversal behavior. Similarly, Mg-included glass exhibits an inverse trend for Poisson’s ratio and fractal bond connectivity parameters. Furthermore, the evaluation of optical features like bandgap energy was achieved from the absorption analysis. The formation of bridging oxygens is observed to be in accordance with oxygen packing density values.

A novel traditional Chinese medicine combination for radiation

ObjectiveTo formulate an efficacious radioprotective combination of Chinese medicines with minimal toxicity. MethodsAqueous and alcoholic extracts from 38 traditional Chinese herbs were prepared. To produce drug-containing sera, rats received six doses of each extract via oral gavage at 12-h intervals. Subsequently, human lung epithelial BEAS-2B cells were cultured in these drug-containing sera. The cell viability was assessed after different doses of irradiation to identify the radioprotective effects of Chinese herbal extracts. The efficacy of a selected Chinese herbal extract combination was further confirmed through cell viability analysis via in vitro colony formation and survival rate assessments in C57BL/6 mice post-irradiation. ResultsExtracts from Angelicae Sinensis Radix (ASR; two extracts), Citri Reticulatae Pericarpium (CRP), Platycladi Cacumen (PC), Schisandrae chinensis Fructus (SF), Scutellariae Radix (SR), and Glycyrrhizae Radix et Rhizome (GRR) demonstrated radioprotective effects. The combination of the seven Chinese herbal extracts notably increased the survival and viability of the BEAS-2B cells exposed to varying doses of X-rays. Moreover, the group of mice receiving Chinese medicine combination and irradiation exhibited prolonged survival after exposure to 6.5 ​Gy X-rays with a median survival of （14 ​± ​2）d compared to （11 ​± ​2）d in the irradiated group without the herbal treatment. Additionally, the Chinese medicine combination group displayed a significantly higher 28 ​d survival rate (30%) compared to the irradiation-only group (16.6%, P ​< ​0.05). ConclusionThe novel combination of Chinese herbal extracts from ASR, CRP, PC, SF, SR, and GRR has the potential for radiation protection applications.

Mass attenuation Coefficient and Total cross-section Area of Platinum Group Composition

Radiation shielding is a critical practice involving the utilization of materials or barriers to safeguard against ionizing radiation by absorbing, scattering, or blocking the radiation. Its primary objective is to curtail exposure and mitigate potential health risks associated with radiation. In diverse fields like medicine, industry, and nuclear applications, radiation shielding materials play a pivotal role in ensuring the safety of individuals and equipment, contributing significantly to the maintenance of secure environments. This study focuses on characterizing materials for radiation shielding, particularly of Platinum group alloys in varying compositions with hydrogen. Using the Klein-Nishina (KN) formula, the investigation calculates electronic cross-sections (ECS), total mixture cross-section (TMCS), and mass attenuation coefficient (MAC) for different weight percentages of Platinum group alloys (0.1 to 0.6) when exposed to γ-ray photons of various energies. The outcomes emphasize the strong dependence of these cross-sections and MAC on photon energy and the charge number of the material, revealing a decrease with increasing photon energy and an increase with the charge number to mass number ratio (Z/A). The research underscores that fundamental parameters such as charge number, photon energy, and Z/A can be manipulated to enhance the utility of these elements in radiation shielding, protection, dose measurements, and imaging. The study's implications extend to the optimization of Platinum Group alloy compositions, offering insights for the development of tailored materials with enhanced shielding effectiveness in radiation protection and safety applications.

Palmitoyl ascorbic acid glucoside enhanced cell survival with post irradiation treatment

Radiation exposure poses a significant threat to cellular integrity by inducing DNA damage through the generation of free radicals and reactive oxygen species. Ascorbic acid, particularly its derivative Palmitoyl Ascorbic Acid 2-Glucoside (PA2G), has demonstrated remarkable radioprotective properties. While previous research focused on its pre-irradiation application, this study explores the post-irradiation radiomitigation potential of PA2G. Our findings reveal that post-irradiation treatment with PA2G enhances cell survival and accelerates DNA repair processes, particularly the non-homologous end-joining (NHEJ) repair pathway. Notably, PA2G treatment reduces the frequency of lethal chromosomal aberrations and micronuclei formation, indicating its ability to enhance the repair of complex DNA lesions. Furthermore, PA2G is shown to play a role in potentially lethal damage repair (PLDR). These radioprotective effects are specific to NHEJ and ATM pathways, as cells deficient in these mechanisms do not benefit from PA2G treatment. This study highlights PA2G as a versatile radioprotector, both pre- and post-irradiation, with significant potential for applications in radiation therapy and protection, offering new insights into its mechanism of action. Further research is required to elucidate the precise molecular mechanisms underlying PA2G's radiomitigation effects and its potential clinical applications.

Investigated mechanical, physical parameters and Gamma-Neutron radiation shielding of the rare earth (Er2O3/CeO2) doped barium borate glass: Role of the melting time and temperature

In this study, we aimed to explore the effects of CeO2/Er2O3, melting time, and temperature on the physical, radiation shielding, and mechanical properties of a glass composition. Specifically, we examined a glass composition comprising of 60B2O3-(40-X) BaO-XMO (where MO- Er2O3/CeO2 and X = 0.5,1.0,1.5 mol percentage). To assess the radiation shielding capabilities of the glass structure, we conducted theoretical evaluations including determining the mass Attenuation Coefficients (MAC), Fast Neutron Removal Cross-Section (FNRCS), and Mean Free Path (MFP). Furthermore, the study involved investigating the mechanical properties of borate glasses with CeO2 and Er2O3 doping, specifically examining Young's modulus, Bulk modulus, Shear modulus, and Longitudinal modulus. The obtained results were then compared. In order to determine the radiation shielding parameters, the Phy-X/PSD program and Geant4 simulation were utilized, covering an energy range from 0 to 10 MeV. The results indicate that there is strong agreement between the Phy-X/PSD and Monte Carlo simulation results for MAC values for glass samples. Our research suggests that these glasses have superior radiation shielding capabilities compared to commonly used materials for blocking radiation. This suggests that these glasses have great potential for use as effective shielding materials in radiation protection applications. It was observed that doping 1.5 mol% of Er2O3 in the lowest temperature and the longest time decreased the reflectivity of the gamma rays of the barium borate glass compared to the doping 1.5 mol% of CeO2.

Radiation attenuation characteristics of meta-schist modified Portland cement: Comparative analysis with traditional cement

As the applications of nuclear technology increase in today's world, radiation protection becomes even more crucial. Radiation shielding is significant in various applications, such as nuclear power plants, medical imaging devices, and radiotherapy rooms. This study investigates the production of meta-schist-modified Portland cement (MMPC) to protect against atomic radiation, which poses harmful environmental effects such as gamma rays, in the context of nuclear technology implementation. The samples' mass attenuation coefficient (MAC) is experimentally determined to assess their radiation shielding capabilities. The Meta-schist-modified Portland cement exhibits higher effectiveness in radiation absorption and attenuation than traditional Portland cement(OPC). Radiation shielding tests demonstrate that MMPC is a practical material for controlling radiation due to its high density and appropriate composition. Overall, the cement sample containing meta-schist shows a high potential for radiation protection applications, and the superior properties of MMPC in terms of burnability and mechanical characteristics compared to traditional Portland cement are encouraging for the use of meta-schist in cement production. The analyses of cement and clinker samples were conducted using analytical techniques such as microstructure characterization (POLYZED MICROSCOPE), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDAX). This study highlights meta-schist-modified Portland cement's effective radiation protection potential and demonstrates the significance of advancing safety measures in nuclear technology applications.

Radioactivity study of EAST structural materials based on neutron activation system

The plasma operation in the Experimental Advanced Superconducting Tokamak (EAST) would generate 2.45 MeV neutrons and a small fraction of 14 MeV neutrons. Neutrons react with structural materials, leading to the production of radioactive isotopes. The identification of nuclides and the determination of radioactive activity are of great significance for radiation protection and fusion material applications. In this study, structural materials including stainless steel 316L(SS316L), stainless steel 304L(SS304L), aluminum(Al), tungsten(W) and copper(Cu) were transported to the activation terminal for fusion neutron irradiation. The gamma ray spectra were measured using high-purity germanium (HPGe) detector, and the main radioactive nuclides of SS316L and SS304L are 56Mn, while the main radioactive nuclide of Al is 28Al. For Cu and W, the main radionuclides resulting from neutron reactions are 66Cu and 187W, respectively. The uncertainty of the radioactivity is 2.27∼7.94 % for W, 1.95∼5.84 % for SS316L, 2.10∼6.07 % for SS304L, 0.68∼1.69 % for Al and 2.59∼6.75 % for Cu. The specific activity of radionuclides is proportional to neutron yield, so the material activation is the main source of radiation dose during irradiation with high-yield neutron. The neutron activation coefficients of SS316L, SS304L, Al, Cu and W are 2.74538 × 10−14, 3.6411 × 10−14, 2.50711 × 10−12, 1.76506 × 10−12 and 3.51725 × 10−14, respectively. The coefficient represents the radioactive activity generated by each fusion neutron. In addition, the predicted activity was calculated using FISPACT program and compared with experiments.

Novel bricks based lightweight Vietnam's white clay minerals for gamma ray shielding purposes: An extensive experimental study

In the present work, a new brick series based on the Vietnamese white clay minerals from the Bat Trang was fabricated to be applied in the radiation protection applications during the decommissioning of the nuclear power reactors. The bricks were constructed under various pressure rates varied from 7.61 MPa to 114.22 MPa. The influence of pressure rate on the physical and γ-ray shielding properties were investigated in the study. The experimental measurement for the material's density using the MH-300A density meter showed an enhancement in the prepared bricks' density by 22.5 % with increasing the applied pressure rate while the bricks' porosity reduced by 31.2 % when the pressure rate increased from 7.61 MPa to 114.22 MPa. The increase in the fabricated bricks density and the reduction in their porosities enhances the bricks' linear attenuation coefficients as measured by the NaI (Tl) detector along the energy range extended from 0.662 MeV to 1.332 MeV. The linear attenuation coefficient increased by 13.8 %, 17.6 %, 17.0 %, and 17.1 % at gamma ray energies of 0.662 MeV, 1.173 MeV, 1.252 MeV, and 1.332 MeV, respectively. The enhancement in the linear attenuation coefficient increases the bricks' radiation protection efficiency by 10.22 %, 14.48 %, 14.09 %, and 14.26 % at gamma ray energies of 0.662 MeV, 1.173 MeV, 1.252 MeV, and 1.332 MeV, respectively.

Radiation attenuation of boro-tellurite glasses for efficient shielding applications

The borotellurite glasses whose chemical structure is (29.5–0.4x)CaO + 10CaF2 + (60–0.6x)B2O3 + xTeO2+ 0.5Yb2O3 (where x=10, 16, 22, 31, and 54 % mole. represent TCCBY1-TCCBY5, respectively) are Pb-free, thermally stable, and transparent glasses with attractive optical features for technological applications. The gamma-photons, electrons, protons, neutrons, carbon ions, fast neutrons, and fast neutron interaction parameters of these glasses are presented in this study to better understand the role of TeO2 in influencing their radiation shielding properties and radiation protection applications. The photon mass attenuation coefficient was evaluated by XCOM computation and simulation using the FLUKA code. The FLUKA code was also used to evaluate the mass stopping powers of the charged radiations, while neutrons’ cross sections were evaluated using standard expressions. For 0.015 MeV–15 MeV photons, the mass attenuation coefficients of the glasses fell from 17.9499 to 0.0246 cm2/g for TCCBY1, 20.5628 to 0.0263 cm2/g for TCCBY2, 23.2756 to 0.079 cm2/g for TCCBY3, 26.7487 to 0.0298 cm2/g for TCCBY4, and 33.3591 to 0.0335 cm2/g for TCCBY5. The photon half-value layer at 15 keV is reduced by about 19.57%, 32.68%, 48.84%, and 63.89% when the TeO2 content increases from 10 mol to 16, 22, 31, and 54 mol, respectively. TeO2 was found to suppress photon buildup in the glasses. The mass stopping powers of charged radiation increased as glass density decreased. The addition of TeO2 into the glass structure increased the ability of the TCCBY glass to absorb fast neutrons by up to 54 % mole. The gamma radiation and fast neutron moderating ability of TCCBY5 glass compared to common shields and other materials is exceptional. The glass is recommended for the design of Pb-free, transparent, and efficient radiation protection structures.

Radiation shielding capacity and machine learning density prediction of boro-bismuth cadmium zinc glasses

Bismuth borate cadmium zinc glasses were prepared using melt quenching technique for shielding applications. The glasses had the composition (80-x)B2O3-xBi2O3-10CdO-10ZnO, where 0<x<20mol%. The densities of the glasses were predicted using machine learning tools and were found to increase with increasing Bi2O3 content. This increase in density was correlated with changes in the infrared spectrum of the glasses. The density of the glass changed from 4.410 g/cm³ to 6.9830 g/cm³ when bismuth oxide (Bi2O3) was added to the glass network. This is because Bi2O3 changes the structure of the glass. The presence of octahedral BiO6 units in the glass is confirmed by the peak at 514 cm-1 in the infrared spectrum. This peak shifts to a lower wavenumber as the amount of Bi2O3 in the glass increases. The shift of the infrared peak from 688 cm-1 to 596 cm-1 indicates that Bi2O3 is actively participating in the glass network, which results in a decrease in the number of BO3 units. The shift of the infrared peak from 1060 cm-1 to 1137 cm-1 is attributed to B-O stretching vibrations in BO4- units, and also confirms that the number of BO4 units is increasing. The density of the glass was predicted using machine learning algorithms that are trained on the chemical composition and experimental density of glasses. Polynomial regression and artificial neural networks (ANNs) were used to predict the density of glass from its chemical composition. Polynomial regression performed best with a 10th-degree polynomial, with an R2 value of 0.8820. ANNs performed best with a tanh activation function, with an R2 value of 0.8923. Random forest regression performed better than other machine learning models at predicting the density of glass, with an R2 value of 0.920. The predicted values were very close to the experimental values. The mass (MAC) and linear (LAC) attenuation coefficients of radiation shielding followed the following trend: (MAC, LAC)0 < (MAC, LAC)5 < (MAC, LAC)10 < (MAC, LAC)15 < (MAC, LAC)20. The half value layer followed the trend: HVL followed as: (HVL)0 > (HVL)5 > (HVL)10 > (HVL)15 > (HVL)20. The Radiation Protection Effectiveness (RPE) reinforces the superiority of BBCZ-20 glasses in shielding against gamma radiation, making them promising candidates for radiation protection applications.

Unveiling the potentials of polyvinyl alcohol/manganese chloride nanocomposites films: A detailed examination of their structural, spectral, and radiation properties

Recently, the introduction of inorganic nanoparticles, such as Manganese Chloride (MnCl2), as fillers in these polymers has emerged as an intriguing area of research, potentially enhancing their properties, and expanding their applications further. This study provides a comprehensive investigation into the influence of MnCl2 nanoparticles on PVA, forming PVA/ MnCl2 polymeric nanocomposite films. The research aims to enhance the understanding of the interactions between PVA and MnCl2, and the resultant structural, spectral, and radiation properties of the investigated nanocomposite films. The study incorporated the preparation of films with varying weight percentages of MnCl2 nanoparticles. X-ray diffraction patterns confirmed the presence of MnCl2 within the PVA structure and suggested strong interactions between the constituents. The FTIR spectral analysis was conducted to identify changes in the chemical bonds due to MnCl2 doping, employing spectral deconvolution to gain deeper insights into these changes. The study also considered density measurements using Archimedes’ principle, providing insights into the physical properties of the nanocomposites. The radiation interaction properties of the polymeric nanocomposite films were evaluated to explore potential applications in radiation protection. The results shed light on the impact of MnCl2 doping on PVA and suggest the promising potential of these nanocomposites in numerous applications, including optoelectronics and radiation shielding. This study propels the understanding of polymer-nanoparticle interactions forward, offering valuable insights into the design and application of polymeric nanocomposites.

Hubungan Pengetahuan dan Kepatuhan Penerapan Proteksi Radiasi: Studi pada Mahasiswa Praktik Klinik Jurusan Teknik Radiodiagnostik dan Radioterapi, Poltekkes Kemenkes Semarang

Background: Radiation protection is very important for patient and personnel safety in radiology services. It has been given in the college through classical lectures, including in Radiodiagnostic and Radiotherapy Department Poltekkes Kemenkes Semarang. The student’s knowledge is routinely evaluated but their compliance in the clinical activities has never been specifically observed. This study aims to find out the relationship between knowledge toward compliance of the application of radiation protection on clinical practice students.Methods: This is quantitative research with a cross-sectional design. Research was conducted on 90 second-year clinical internship students of the Radiodiagnostic and Radiotherapy Department. The level of knowledge was measured by written test, while the level of compliance was observed by clinical observation. The affecting factors are investigated through indepth interview. Data were analyzed by Spearman Rank Correlation.Results: The knowledge levels among the students were "excellent” (18%), "good" (68%), and "fair" (14%). The radiation protection compliance levels were "good" (73%) and "very good" (27%). There was a significant relationship between radiation protection knowledge level toward radiation protection compliance (p value 0.05). The strength of the relationship was low (coefficient interval = 0.257). Conclusions: There was a relationship between knowledge and the level of compliance, but it was not the only influencing factor. The environment tends to have an effect on the level of compliance. Radiographers and clinical instructors should be good role model in applying radiation protection.

A preliminary appraisal for utilizing abandoned industrial side streams as alternatives to cement within radiation protection applications

Recently, there has been arising a severe alert regarding climate crisis all over the world. As industrial production capacities have been soaring every passing day, the primary sources of the earth's crust have been depleting like there is no tomorrow. Sustainable and greener suggestions should be followed to overcome the upcoming catastrophic climate change. With this motivation, cement material, whose influence on global warming is excessive, has been studied to be replaced by alternative material systems in different application areas, and radiation shielding applications may be regarded as one of these emerging fields. In this study, the authors were motivated to replace ordinary Portland cement (OPC) with alternative side streams (SS) that have accumulated in nature without any benefits. First, the high-quantity SS were determined and presented as follows: fly ash (FA), blast furnace slag (BFS), red mud (RM), electric arc furnace slag (EAFS), fayalite slag (FS), rice husk ash (RHA), silica fume (SF), ferrochrome slag (FS), and copper mining tailings (CMT). Each side stream's average chemical compositions were obtained, and their theoretical density values were calculated. After that, the theoretical radiation shielding properties were assessed using Phy-X/PSD software within the 0.15–15 MeV photon energy range. Some essential parameters such as linear attenuation coefficient (LAC), half-value layer (HVL), effective atomic number (Zeff), radiation protection efficiency (RPE), and build-up factors (EBF and EABF) paved the way for comparing SS with OPC material. The results for radiation protection demonstrated that high-density-oxide-containing SS like RM, FS, and EAFS could replace OPC material with a good performance. Owing to this replacement, the authors strongly believe that the future can be sustained in a more secure environment without OPC material, but with SS in radiation shielding applications.

Newly-formulated zinc-bismuth-barium-sodium-silicate glass system with lead oxide addition: Probing radiation shielding characteristics via triple methodology

In recent times, glass materials appear to be strong candidates for radiation protection applications. In this study, a zinc-bismuth-barium-sodium-silicate (ZBBSS) glass system with a formulation of 10ZnO – 20Bi2O3– 5BaO – 15Na2O – (50-x) SiO2– xPbO, x: 0, 5, 15 and 25 wt% was synthesized. The traditional melting technique (1325–1375 °C) enabled the synthesis of four different glass samples coded ZBBSS1 to ZBBSS4. Following synthesis, Archimedes' principle, XRD, FTIR, UV-Vis, and DSC techniques showed physical, structural, optical, and thermal property alterations as a function of PbO inclusion, while the triple methodology (experimental, theoretical, and simulation) revealed radiation attenuation aspects in a broader sense. According to the findings, ZBBSS1 had density of 3.1107 g/cm3 while the other samples had density values of 3.2285, 3.6053, and 4.0158 g/cm3 in respective order. The clear existence of non-crystalline structure for the ZBBSS glass series was reported. Similar vibrational modes were found for ZBBSS glass systems, and -OH, Si-OH, Si-O-Si, and Pb-O-Pb bonding types were assigned to peak formations. For determination of thermal properties, it was observed that Tg became lower, from 520.6 to 392.4 °C, in parallel to the increment in the PbO doping rate. Additionally, an increase in the PbO doping rate hindered the transmission phenomenon based on UV-Vis spectra. Gamma absorption coefficients were measured at six energies with four sources using the gamma spectroscopic system. The measured values were compared with the FLUKA code and Phy-X software. Experimental LAC values of 0.2463, 0.2729, 0.3064, and 0.3618 cm−1 were measured using a Cs-137 source for the ZBBSS glass series, respectively. The variation in the values obtained with the triple methodology overlapped with each other for all energies. Among the prepared glasses, the best LAC and MAC, thinnest HVL, lowest MFP and TF were determined for ZBBSS4 glass sample with maximum PbO content. From the results obtained, it is concluded that the addition of PbO is a useful way to improve the gamma attenuation capacity, and among the glasses examined, ZBBSS4 had superior protection against gamma rays.

Multifunctional phase change textiles with electromagnetic interference shielding and multiple thermal response characteristics

Electromagnetic interference (EMI) shielding textiles with flexible thermal response are ideal candidates for applications in electromagnetic radiation protection, flexible electronic and information security. In general, silicone resins used to encapsulate textiles can delay the thermal response, which seriously limits the application of textiles in multiple scenarios. Herein, we have developed a flexible solid–solid phase change material (PCM) coating which is achieved by self-crosslinking polyethylene glycol (PEG) with highly reactive silanol group obtained by reaction with 3-isocyanatopropyltriethoxysilane (IPTS). The solid–solid PCM coating retains the phase change behavior of original PEG while providing excellent shape stabilization. Subsequently, the solid–solid PCM coating is used to encapsulate polymer textiles decorated with silver nanowires (AgNWs) based on a scalable dip coating strategy. Notably, the phase change textiles have an EMI shielding effectiveness of approximately 72 dB at the thickness of 0.26 mm and exhibit an energy storage density of 86.6 J g−1. Meanwhile, the textiles exhibit flexible thermal response such as high joule heating efficiency, excellent heat storage and release, good heat dissipation, and infrared anti-counterfeiting behavior. Thus, multifunctional textiles decorated with AgNWs and subsequently encapsulated with solid–solid PCM coatings have great promise for wearable clothing, electromagnetic radiation protection and personal thermal management.

Development of Sustainable Radiation-Shielding Blend Using Natural Rubber/NBR, and Bismuth Filler

This research entailed the production of composite materials through the combination of natural rubber and acrylonitrile butadiene rubber, along with nano-silica-loaded bismuth (III) oxide, in varying concentrations ranging from 0 to 45 parts per hundred parts of rubber (phr). The gamma attenuation properties of the composites at different concentrations of Bi2O3 were measured. Additionally, the mechanical properties of the resulting composites, including hardness, tensile strength, and elongation, were tested. The composites with a concentration of 20 phr exhibited the highest tensile strength and elongation at break, followed by a subsequent decrease as the concentration of Bi2O3 increased. The gamma mass-attenuation coefficient of the composites increased as the Bi2O3 concentration increased from 0 to 45 phr, with values ranging from 0.083 to 0.090 cm2/g at 0.662 MeV. Moreover, the fast neutron mass removal cross-sections ranged from 0.092 to 0.072 cm2/g, corresponding to the variation of Bi2O3 concentration from 0–45 phr are also determined. Various parameters related to gamma-ray shielding, including the half-value layer, exposure build-up factor (EBF) up to 40 mean free path (mfp) penetration depth, and effective atomic number (Zeff) are also included. The radiation-induced aging of the prepared blend is tested by measuring the effect of radiation exposure on its shielding capability via its porosity change. The obtained results indicated that the prepared composites could be used for several radiation-protection applications.

Adsorption of radon on transition metal functionalized graphene monolayer with external effects

The noble gas radon (Rn) is radioactive and can gravely harm the human body. As a result, capturing and dealing with Rn gas is an important task, in terms of radiation protection. The large specific surface area of graphene renders it a potential candidate for gas adsorption applications. Along these lines, in this work, theoretical calculations based on the density functional theory were presented to systematically explore the adsorption properties of Rn on transition metal (TM) functionalized graphene monolayer. The adsorption energies of Rn atoms on the functional graphene were estimated up to −0.873 eV, according to our computed results. The increase in the concentration of Rn atoms and the ambient temperature led to a reduction in the adsorption energy of Rn on the surface. To effectively control the adsorption characteristics, electric field and stress were externally added. The calculation results showed that a negative electric field and proper deformation could significantly improve the adsorption of Rn to TM functionalized graphene. In this work, it was demonstrated that TM functionalized graphene could be successfully used as an adsorber of Rn atoms with promising results. In addition, the adsorption properties can be controlled and enhanced under the application of an external field, as well as a stress load, which is of great significance for application in radiation protection.

Hollow Co/NC@MnO2 polyhedrons with enhanced synergistic effect for high-efficiency microwave absorption

High-efficiency microwave absorbents with lightweight characteristics possess prospective applications in electromagnetic radiation protection, but still face huge challenges. Herein, hollow Co/NC@MnO2 (H–Co/NC@MnO2) polyhedrons with hierarchical structure and enhanced synergistic effect are successfully fabricated via the collaborative steps of etching-pyrolysis-hydrothermal reaction. Specifically, hollow engineering of Co/NC with heteroatoms endow the polyhedrons with lightweight characteristics, dipolar polarization and magnetic loss, hierarchical MnO2 nanosheets with oxygen vacancies grant dielectric loss and multiple scattering, and the dielectric-magnetic synergistic effect between Co/NC and MnO2 promote impedance matching and strengthen interfacial polarization. Benefiting from the above mentioned advantages, the H–Co/NC@MnO2 polyhedrons exhibit high-efficiency microwave attenuation at a low filler loading of 20 wt%. The optimal reflection loss reaches −54.7 dB and the effective absorption bandwidth ranges from 11.8 GHz to 18 GHz (6.2 GHz) with a thickness of only 2.1 mm. These findings provide us a promising strategy in developing high-efficiency and lightweight microwave absorbents for practical applications.

Gamma-ray attenuation parameters of HDPE filled with different nano-size and Bulk WO3

High-density polyethylene (HDPE) was obtained through a compression molding technique, and incorporated with different filler weight fractions (0, 10, 15, 25, and 35%) of bulk WO3, and two different WO3 nanoparticle sizes (45 nm and 24 nm). The radiation attenuation ability of the new category of polymer composite HDPE/WO3 was evaluated using gamma-ray energies ranging from 59.53 up to 1332.5keV of four radioactive sources 241Am, 133Ba, 137Cs, and 60Co. The mass attenuation coefficients μm, the total molecular cross-section σmol, the effective atomic cross-section σatom, the total electronic cross-section σel, the effective atomic number Zeff, electron density Neff, the half value layer (HVL), the tenth value layer (TVL), and the relaxation length were investigated. The obtained results of the gamma-ray attenuation parameters exhibited an outstanding influence of the size and weight fraction of WO3 filler on the gamma-ray shielding ability of the HDPE composite. A significant improvement was detected at low gamma-ray energies. The HVL of the synthesized HDPE composites is compared with that of pure lead as a conventional shielding material. HDPE composite filled with the smaller size of WO3 nanoparticle shows good improvement in the attenuation parameters, which suggests promising applications in radiation protection and gamma-ray shielding.