Attenuation Properties Research Articles

Study of attenuation characteristics for novel neonatal head phantom in diagnostic radiology using Monte Carlo simulations and experiments.

This study presents the design and validation of a neonatal head phantom using innovative heterogeneous composite materials customized to replicate the X-ray attenuation properties of neonatal cranial structures. Analysis of Hounsfield Unit (HU) data from 338 neonatal head CT scans informed the design of epoxy resin-based composites with additives such as sodium bicarbonate, fumed silica, and acetone to simulate bone, brain matter, cerebrospinal fluid (CSF) and hyperdense abnormalities. The cranial bone substitute (60% epoxy resin, 40% sodium bicarbonate) achieved a density of 1.60 g/cm³, with HU values (574.67-608.04) closely matching clinical ranges. Brain matter (95% epoxy resin, 5% acetone) achieved HU values (35.27-43.61), aligning with clinical means, while the CSF-equivalent material (80% epoxy resin, 15% fumed silica, 5% acetone) matched neonatal CSF HU values (14.53-17.02). A mass substitute for hyperdense abnormalities exhibited HU values (56.16-61.07), enabling differentiation from normal brain. Validation included Monte Carlo simulations and experimental CT imaging, showing close agreement in linear attenuation coefficients, with deviations below 11% across energy levels. Mass attenuation coefficients from simulations and XCOM software were consistent, with deviations under 0.7%, confirming the materials dosimetric reliability. The phantom, with a cylindrical geometry (9 cm diameter, 10 cm length), provides accurate attenuation properties across 80-120 kVp energy levels, with deviations below 5% between experimental CT numbers and simulation data. This phantom offers a robust platform for neonatal imaging research, enabling impactful dose optimization and imaging protocol adjustment and supports improved diagnostic accuracy in pediatric imaging.

Synergistic Strategy of Hard-Template Etching and Soft-Template Protection for Rapid Fabrication of Aerogel Short Fibers

Aerogel fibers are produced by integrating aerogel nanonetworks with structures possessing large aspect ratios, which provide enhanced thermal insulation, noise attenuation, and pollutant adsorption properties compared to those of bulk aerogels. The conventional method for fabricating aerogel fibers, which involves dynamic spinning, depends on the swift solidification of gels within a coagulation bath. This process inevitably affects the gel's internal three-dimensional network structure after it has assumed a formed state, posing substantial difficulties in regulating the pore structure and mechanical strength of the aerogel fibers. In this research, we present a novel technique for the fabrication of poly(methylsilsesquioxane) aerogel short fibers (PAFs), utilizing an ice template-based static molding process. Directional ice crystals act as "hard templates" to form prismatic structures within the wet gel matrix, whereas the electrostatic repulsion from the "soft template," cetyltrimethylammonium bromide (CTAB), safeguards the fiber structure during its formation. Furthermore, the internal pore structure of the aerogel can be precisely controlled by modulating the aggregation states of CTAB micelles in water, which offers diverse reaction sites for silane hydrolysis. The fibers fabricated using this method exhibit large aspect ratios, low density, high specific surface area, and flexibility, displaying excellent insulation properties, stability at high and low temperatures, and hydrophobicity. They are suitable for use as functional fillers in high-performance wearable fabrics.

Optimized physical and radiation attenuation properties of Er3+-Doped strontium potassium bismuth-boro-tellurite glass systems: An experimental study

Optimized physical and radiation attenuation properties of Er3+-Doped strontium potassium bismuth-boro-tellurite glass systems: An experimental study

Influence of neodymium doping on radiation shielding properties of yttrium lead borotellurite glass system

The need for effective shielding materials has grown as radiation-based technologies have been more widely used. Glasses doped with rare earth elements like neodymium oxide, are promising candidates due to their enhanced radiation attenuation properties. Using Phy-X software, this research examines how neodymium oxide doping affects the shielding properties of yttrium lead borotellurite glass. X-ray diffraction confirmed the amorphous structure, while density measurements showed increased density with neodymium oxide addition. The Phy-X software calculated radiation shielding parameters for gamma energies from 10⁻³ to 10⁵ MeV. The results demonstrate that neodymium oxide improves gamma irradiation attenuation and enhances the glass system's radiation shielding capabilities.

Separating edges from microstructure in X-ray dark-field imaging: evolving and devolving perspectives via the X-ray Fokker-Planck equation.

A key contribution to X-ray dark-field (XDF) contrast is the diffusion of X-rays by sample structures smaller than the imaging system's spatial resolution; this is related to position-dependent small-angle X-ray scattering. However, some experimental XDF techniques have reported that XDF contrast is also generated by resolvable sample edges. Speckle-based X-ray imaging (SBXI) extracts the XDF by analyzing sample-imposed changes to a reference speckle pattern's visibility. We present an algorithm for SBXI (a variant of our previously developed multimodal intrinsic speckle-tracking (MIST) algorithm) capable of separating these two physically different XDF contrast mechanisms. The algorithm uses what we call the devolving Fokker-Planck equation for paraxial X-ray imaging as its forward model and then solves the associated multimodal inverse problem to retrieve the attenuation, phase, and XDF properties of the sample. Previous MIST variants were based on the evolving Fokker-Planck equation, which considers how a reference-speckle image is modified by the introduction of a sample. The devolving perspective instead considers how the image collected in the presence of the sample and the speckle membrane optically flows in reverse to generate the reference-speckle image when the sample is removed from the system. We compare single- and multiple-exposure multimodal retrieval algorithms from the two Fokker-Planck perspectives. We demonstrate that the devolving perspective can distinguish between two physically different XDF contrast mechanisms, namely, unresolved microstructure- and sharp-edge-induced XDF. This was verified by applying the different retrieval algorithms to two experimental data sets - one phantom sample and one organic sample. We anticipate that this work will be useful in (1) yielding a pair of complementary XDF images that separate sharp-edge diffuse scatter from diffuse scatter due to spatially random unresolved microstructure, (2) XDF computed tomography, where the strong edge XDF signal can lead to strong contaminating streaking artefacts, and (3) sample preparation, as samples will not need to be embedded since the strong XDF edge signal seen between the sample and air can be separated out.

Molecular scattering function data of brain tissue

The interaction of photons with matter is of great importance for the study of energy transfer to the medium. The most sensitive studies on energy transfer are Monte Carlo simulation applications. In Monte Carlo modeling, the calculation of incoherent scattering is important. The incoherent scattering of a photon in a medium is decisive in terms of scattering angle and energy transfer to the medium. By incorporating the incoherent scattering coefficients into the Monte Carlo modeling program, it will be possible to determine the attenuation properties of photons of different energies interacting in the matter. In this study, incoherent scattering functions necessary for calculating molecular incoherent scattering coefficients were obtained by using atomic data according to the molecular content of white and gray brain matter. We believe that our results can be used and will be beneficial for researchers who make models and work experimentally.

UHPC Viability for Nuclear Storage Facilities: Synthesis and Critical Review of Durability, Thermal, and Nuclear Properties for Informed Mix Modifications.

Spent nuclear fuel (SNF) from the United States' nuclear power plants has been placed in dry cask storage systems since the 1980s. Due to the lack of a clear path for permanent geological repository for SNF, consolidated and long-term storage solutions that use durable concrete and avoid current aging and licensing challenges are becoming indispensable. Ultra-high-performance concrete (UHPC) is a rapidly growing advanced concrete solution with superior mechanical and durability properties that can help realize future resilient nuclear storage facilities. Thus, the overall goal of this review study is to demonstrate the viability of UHPC as a long-term solution for future nuclear storage facilities. The paper first identifies all possible non-nuclear (environmental) and nuclear (thermal and radiation-induced) degradation mechanisms in concrete overpacks and storage modules with critical assessment and projections on UHPC performance in comparison to current conventional concrete solutions. Next, since concrete serves as a shielding material in nuclear settings, the preliminary attenuation properties of UHPC from emerging studies are synthesized along with the possible mix modifications to improve its attenuation performance. The paper identifies the major knowledge gaps to inform future research and development, aimed at rethinking the design of SNF dry storage facilities by incorporating UHPC.

Gamma attenuation and radiation shielding properties of lead silicate glasses containing antimony and alumina oxides

Lead silicate glasses have been widely used in various applications, including radiation shielding, due to their high density and effective atomic number. However, the addition of certain oxides to the glass composition can significantly enhance their radiation shielding properties. In this study, we investigate the effect of incorporating antimony and alumina oxides on the photon attenuation and shielding properties of lead silicate glasses. It is found that the HVL values of the APSSS1 sample started from 0.00239 cm at photon energy of 0.015 MeV and increased with increasing energy to a maximum value of 4.223 cm at 6 MeV photon energy then decreased to 3.767 cm at energy of 15 MeV. Moreover, the shielding ability of the studied samples are compared with commercial glassy materials. The results of the study showed that the addition of antimony and alumina oxides significantly improved the radiation shielding properties of the lead silicate glasses.

Alternative X-ray attenuation material from iodide-starch-gel-based materials

Background: Iodine is often used as a contrast media because the k-shell binding energy (K-edge) is 33.2 keV, the average energy of a diagnostic X-ray. Thus, iodine can be utilized as a radiation attenuation material for X-rays. Objective: This study aimed to produce low-energy X-ray attenuation materials used as X-ray shielding. A sodium iodide compound will be synthesized by polymerizing mung bean starch with sodium iodide. Materials and methods: The iodide-starch-gel-based material (ISG) was made by mixing a mung bean starch solution (10 %w/w) with a sodium iodide (NaI) solution (100, 200, 250, and 300 mg-Iodine/gm). The linear attenuation coefficient (µ) was determined using radiation dose acquired from the DR plate system and CdTe detector. The X-rays were done at 50 - 120 kVp to study the attenuation properties. Results: The results showed that the linear attenuation coefficient of t ISG was slightly higher than that of sodium iodide solution at the same concentration. The spectrum still shows an X-ray absorption characteristic at about 30.1-40.5 keV K-edge range. Conclusion: Iodide-starch-gel-based components can attenuate X-ray with a K-edge range from 30-40 kVp. The attenuation coefficient of X-ray radiation varies linearly with energy level. Moreover, the concentration of the NaI solution is directly proportional to the attenuation of X-ray radiation. Thus, based on these properties and the gel-like consistency of the substance, it can be developed into a surface coating material to reduce X-ray radiation exposure.

Optimizing gamma radiation shielding in Pr3+ doped boro-tellurite glasses: a study of attenuation properties and performance

Abstract A series of Pr3+ doped boro tellurite glass samples are synthesized using melt quenching technique and investigated for their potential in gamma ray shielding applications. The amorphous nature of prepared samples is confirmed through X-Ray diffraction technique. The shielding characteristics of prepared glass samples were assessed by determining various parameters, including the linear attenuation coefficient (LAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and mass attenuation coefficient (MAC) across the energy range of 15 keV to 15 MeV. The significant decrease in the linear attenuation coefficient (LAC) for all the prepared samples indicates their enhanced radiation attenuation capabilities. Furthermore, it was observed that LAC values are nearly consistent in the energy range from 1.5 MeV<E<15 MeV, for all the prepared samples, demonstrating its independence from the atomic number of the sample. Additionally, HVL values decreases in the energy range from 8 MeV -15 MeV for all the prepared samples which underscores its exceptional efficacy in radiation shielding. This significant reduction in HVL indicates that the Pr3+- doped glass provides superior attenuation of gamma radiation, making it an excellent choice for applications where effective radiation protection is critical. A sharp peak at 40KeV is observed in Zeff graph showing the dominance of Te absorption edge. The higher values of Zeff at 0.6 MeV for all the prepared samples in this study are evident compared to those reported for lead borate, lead silicate, and lead phosphate in the literature. The current study highlights the effectiveness of the prepared samples as gamma radiation shielding materials.

Investigation of Gamma Attenuation Property of Different Brands of Quartz Samples Used for Wall Cladding in Ethiopia as a Function of Two Gamma Energies 59.6kev and 662kev

Investigation of Gamma Attenuation Property of Different Brands of Quartz Samples Used for Wall Cladding in Ethiopia as a Function of Two Gamma Energies 59.6kev and 662kev

High-Density Lead Germanate Glasses with Enhanced Gamma and Neutron Shielding Performance: Impact of PbO Concentration on Attenuation Properties

Lead germanate glasses, improved with lead oxide (PbO), have emerged as effective materials for radiation shielding due to their increased density and structural robustness. The goal of this study is to find out how well lead germanate glasses with PbO concentrations between 20 and 55 mol% can block gamma rays and neutrons. The Phy-X/PSD software was used to obtain important numbers like the mass attenuation coefficient (MAC), the linear attenuation coefficient (LAC), the half-value layer (HVL), the mean free path (MFP), and the fast neutron removal cross section (FNRCS). The results show that the 55PbGe sample, which has the most PbO, has better gamma-ray attenuation and a low energy absorption buildup factor (EABF). This makes it a good choice option for locations requiring compact but efficient radiation shielding. The 50PbGe sample, on the other hand, demonstrates effective neutron shielding capabilities, suggesting it may be suitable for applications requiring protection against both gamma and neutron exposure. Higher PbO content is linked to better radiation blocking, which supports the idea that lead germanate glasses could be used instead of traditional lead-based shielding materials.

Physical and Gamma Ray Attenuation Properties of Bismuth-Lead-Phosphate Glass

In this paper, the physical characteristics and radiation attenuation parameters of five ternary (50-x) PbO-xBi2O3-50P2O5 glass samples with different compositions were examined. The physical properties investigated were glass density (ρ), molar volume (VM), molar volume of oxygen (VO), and oxygen packing density (OPD). An empirical formula was used to determine the glass density theoretically and compared with the experimental density obtained from the Archimedes method. The comparison yielded reasonable results but did not achieve the desired level of accuracy as expected. The findings revealed that both density and molar volume exhibited an increase with higher Bi2O3 content. However, the molar volume of oxygen (VO) and oxygen packing density (OPD) show inconsistent behavior, showing a slight increase in VO and a decrease in OPD. Furthermore, the essential radiation properties, including the coefficient of linear attenuation (LAC), coefficient of mass attenuation (MAC), half-value layer (HVL), and tenth-value layer (TVL), were determined through experimental and theoretical calculations using the NaI (Tl) detection system and the Phy-X/PSD program, respectively. The results indicated reasonable consistency between the two methods, with the Bi16Pb34P50 sample demonstrating superior radiological properties among the samples. Overall, the study illustrated that the addition of bismuth to phosphate and lead glass improved the glass samples' radiation and physical characteristics.

Gamma‐ray and neutron attenuation of carbon fiber/epoxy composites with carbon nanotubes and boron nitride nanoparticles for passive shielding applications in space

AbstractComposite materials have made far‐reaching changes in the space industry since they have been adopted into the structural and thermal control subsystems of space vehicles because of their several multi‐functions, including being lightweight as well as having advanced mechanical and thermal properties. The use of composites as space radiation shielding materials is also one of the most crucial applications because space radiation is a major impediment for current and future deep‐space missions. Investigation of carbon fiber composites with a diverse array of element and nanoparticle reinforcements has revealed their potential as an alternative to conventional radiation shielding materials in space. This study focused on the alleviation of gamma‐ray and neutron radiation by carbon fiber/epoxy composites incorporated with various weight ratios of carbon nanotube (CNT) and boron nitride (BN) nanoparticles. A narrow beam geometry setup was used for gamma radiation tests with a Cs‐137 gamma‐ray source, while neutron radiation experiments were conducted in a neutron howitzer with a 239Pu‐Be neutron source. Six groups of specimens, namely, pure carbon fiber/epoxy, 0.5 wt% CNT, 0.5 wt% BN, 0.5 wt% CNT + 0.5 wt% BN, 1 wt% CNT + 1 wt% BN, and 2 wt% BN, were examined against these two types of radiation. Results have indicated that the 2 wt% BN specimen showed the best attenuation properties against both gamma‐ray and neutron radiation among all tested specimens; furthermore, it was almost three times more effective against neutron radiation than against gamma‐ray radiation.Highlights Varying weight ratios of CNT and BN nanoparticles used for radiation shielding. A Cs‐137 gamma‐ray source used in narrow beam geometry. Neutron radiation studies were conducted in a 239Pu‐Be neutron howitzer. The 2 wt% BN sample showed the best attenuation against gamma‐ray and neutron radiation. It resulted in an HVL of 6.86 cm for gamma‐ray radiation and 2.13 cm for neutron radiation.

Theoretical Investigation of Gamma Attenuation Properties of Some Metal Oxides with GEANT4-GATE Simulation

This study investigated some oxide material's gamma radiation shielding properties. For this purpose, gamma radiation attenuation properties of composites formed by metal oxides MoO2, La2O3, PbO, and their mixtures were examined at 50 keV, 80 keV, 120 keV, 662 keV, 1173 keV, and 1332 keV energies. Calculations were made using the Geant4-based GATE simulation and compared with the XCOM program. Using the theoretically calculated mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value thickness (HVL), and mean free path (MFP) parameters were found. As a result of the study, it was seen that especially the Mo(80)LaPb mixture showed the best gamma shielding property with high MoO2 content.

Rheology-dependent surface wave characteristics in an advanced geomaterial flexoelectric plate with viscoelastic coating

Abstract This study investigates the transmission of seismic surface waves in a composite framework comprising a viscoelastic layer overlying a flexoelectric material. The study focuses on understanding the impact of different viscoelastic models (Maxwell, Newtonian, and Kelvin-Voigt) and interface conditions (smooth and welded contact) on the damping and dispersion characteristics of these waves. To achieve this, the study employs a variable-separable technique and appropriate boundary conditions to derive complex frequency relations for electrically open and short circuits scenarios. These relations are subsequently divided into real and imaginary parts to examine the dispersion and dampening properties, respectively. Numerical simulations are conducted to analyze the response of flexoelectric coefficient, viscoelastic layer thickness, and bonding parameter on phase velocity and dampening coefficient. The research findings indicate that the attenuation properties of the Maxwell and Newtonian models are lower compared to the Kelvin-Voigt model. Graphical comparisons highlight the influence of viscoelastic models and interface characteristics on wave propagation. This research can help in the development of sensors, energy harvesters, and wave manipulation devices that employ flexoelectric materials with viscoelastic coatings. Knowledge of surface wave dynamics in these structures is vital for their optimal performance.

Influence of bismuth doping on the structural, optical characteristics and radiation attenuation properties of zinc sulfide quantum dots

Influence of bismuth doping on the structural, optical characteristics and radiation attenuation properties of zinc sulfide quantum dots

Gamma attenuation, buildup factors, and radiation shielding performance of CaO-borosilicate glasses

This paper investigates the gamma attenuation properties and radiation shielding performance of CaO-B2O3-SiO2 glasses. Through theoretical analysis, the mass attenuation coefficient (μ/ρ) and its corresponding mass energy-absorption coefficient (μen/ρ) of the selected glasses are computed across various photon energies. The other related parameters such as dose rate, effective atomic number, and buildup factor are also determined and discussed in details. The results reveal that there is a significant variation in the attenuation behaviour with changing glass composition and photon energy. As the photon energy increases beyond a certain point (around 0.3 MeV in this table), the values of (μ/ρ) tend to plateau or decrease slowly. Furthermore, we provide a comparative analysis of the mass attenuation coefficient of the investigated glasses with those of commercial SCHOTT's radiation shielding glasses, offering insights into their relative shielding efficacy. This study contributes to the understanding of the radiation shielding capabilities of CaO-B2O3-SiO2 glasses, offering potential applications in diverse fields requiring effective gamma radiation protection.

Preparation of MWCNT/Fe3O4/Si3N4 ternary composite material and microwave absorption properties

MWCNT/Fe3O4/Si3N4 composite was synthesized via hydrothermal synthesis. The morphology and structure of MWCNT/Fe3O4/Si3N4 were investigated by means of SEM, XPS, XRD, and FT-IR. Their electromagnetic parameters were measured by a vector network analyzer. The microwave attenuation properties of as-synthesized composite could be modulated by regulating the feed ratio of MWCNT, Fe3O4, and Si3N4. According to the different amounts of modified nano Fe3O4 added, they are labelled as S1-S3. When the feed ratio is 3:15:20, the maximum reflection loss value of the sample is −23.3 dB at 14.4 GHz, the corresponding thickness is 2.5 mm, and the corresponding effective absorption bandwidth is 5.36 GHz. Moreover, the test results of the thermogravimetric analyzer show that the composite material has excellent heat resistance. Our research results provide a reference value for the development of excellent heat resistance and high-performance MWCNT-based microwave absorption composite materials.

Elucidating the effect of different divalent metals (Mn, Co, Cu, and Zn) on optical, photocatalytic degradation, reusability and ionizing radiation attenuation properties of lanthanum ferrite nanoparticles

Ferrite nanoparticles are promising materials in various fields due to their unique magnetic and chemical stability, remarkable utilization in photocatalytic degradation, and ionizing radiation attenuation properties. So, in the present work, M0.45La0.1Fe1.45O4 (M = Zn, Mn, Cu, and Co) ferrite nanoparticles (MLF nanoparticles) have been explored as a means for improving optical, photocatalytic degradation, reusability, and ionizing radiation attenuation properties. The obtained optical band gaps are 2.44 ± 0.01 eV, 2.20 ± 0.01 eV, 1.93 ± 0.01 eV and 1.70 ± 0.01 eV for the CuLF, ZnLF, CoLF, and MnLF, respectively. The optical band gaps of all the MLF nanoparticles lie within the visible range, indicating their potential as photocatalysts under visible light. The MnLF nanoferrite shows the best degrading efficiency at 97.29 % for methylene blue dye with outstanding stability and enhanced recyclability. In addition, according to the gamma-ray attenuation characteristics of the MLF nanoparticles, the sample ZnLF shows a promising ability for radiation attenuation due to its higher mass attenuation coefficient in comparison with the mass attenuation coefficient of the other MLF nanoparticles. Also, the ZnLF sample has the highest effective atomic number, and this is due to the high atomic number of Zn element in comparison with the other MLF nanoparticles.