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This paper studies, structurally analyzes, evaluates the morphology, and assesses the gamma-ray and neutron attenuation properties of a composite material composed of M-type hexaferrite BaFe 12 O 19 (BF) doped with three additional compounds: Bi 2 O 3 , V 2 O 5 , and Ce 2 O 3. X-ray diffraction revealed that the structure of BF can be indexed to a hexagonal structure, BF/Bi 2 O 3 to a tetragonal structure, BF/V 2 O 5 to a cubic structure, and BF/Ce 2 O 3 to a trigonal structure. These results were refined using PROFEX software. The Crystallite size of the nano-powders was determined by X-ray line broadening using the Williamson-Hall method. Morphology evaluations illustrated that HR-TEM images for BF, BF/Bi 2 O 3 , BF/V 2 O 5 , and BF/Ce 2 O 3 reveal high crystallinity with a polycrystalline nature. Various attenuation measurements, using the FLUKA Monte Carlo code, aimed to determine the efficacy of these dopants into m-type hexaferrite BF as potential materials for radiation shielding applications. Doping with Bi 2 O 3 into hexaferrite BF markedly enhances its attenuation properties, demonstrating superior Linear Attenuation Coefficient (LAC) values across a broad energy spectrum from 0.16 to 10 MeV. The Mass Attenuation Coefficient (MAC) analysis revealed a pivotal energy threshold at 0.3 MeV. Below this energy, BF presented the highest MAC values. Conversely, for energies equal to or greater than 0.3 MeV, BF exhibited the highest MAC values, affirming its superior gamma photon shielding efficacy. The study of the Half Value Layer (Δ 0.5) and Mean Free Path (MFP) provided additional evidence of the superior shielding performance of BF/Bi 2 O 3. The Δ 0.5 values ranged between 0.128 to 1.240 cm for BF, 0.162 to 1.430 cm for BF/V 2 O 5 , 0.163 to 1.390 cm for BF/Ce 2 O 3 , and 0.162 to 1.210 cm for BF/Bi 2 O 3 , indicating that BF/Bi 2 O 3 requires a thinner layer to halve the gamma-ray intensity, particularly at higher energies. The MFP values further support the improved shielding ability of BF/Bi 2 O 3 , with measurements showing that gamma photons travel the shortest distance before interacting with the material, thereby reducing the potential for radiation exposure. [ABSTRACT FROM AUTHOR]

To study non-traditional glass materials, this investigation created four glass samples composed of (70-x)B 2 O 3 –20TeO 2 -10GeO 2 -xMgO, where x represents the percentage of MgO with values of 20, 25, 30, and 35 mol%. Glasses with high transparency were produced via the accepted melt quenching and annealing method. The samples underwent X-ray diffraction analysis to confirm their glassy structure. Fourier transform infrared spectroscopy was utilized to examine the glass network's various structural groups. The measuring methodology and theoretical calculations were used to calculate a range of physical and mechanical parameters. The cut-off wavelength, as well as the direct and indirect bandgap, and other optical characteristics of the S1–S4 samples were observed using optical absorption. The work utilized Phy-X to acquire the ionizing absorption parameters. The paper demonstrates various glasses' radiation shielding properties, including the effective atomic number, half- and tenth-value layers, linear attenuation coefficient, mass attenuation coefficient, and mean free path. [ABSTRACT FROM AUTHOR]

This work uses pure polyvinyl chloride (PVC) with magnesium oxide (MgO) nanoparticles to enhance PVC's optical and shielding properties. The distribution of MgO nanoparticles in the PVC polymer was shown using a scanning electronic microscope, x‐ray diffraction, and Fourier transform infrared. The prepared samples' optical parameters and thermal analysis are investigated using ultraviolet (UV) spectroscopy and thermogravimetric analysis, respectively. The shielding characteristics parameters for the prepared samples were experimentally tested using a Cs‐137 point source with an energy of 0.662 MeV, and the outcomes were contrasted with what the XCOM software had calculated. Results indicated that optical constants were significantly affected by the addition of MgO wt% concentration. The linear attenuation coefficient was directly proportional to the weight concentration of MgO nanoparticle filler in the PVC matrix, and the ability to absorb UV increased. Adding MgO nanoparticle concentrations improved the PVC composite's radiation shielding behavior. It concluded that the PVC/MgO nanoparticle‐prepared samples are suitable for packaging for industrial applications and apron shielding for medical applications. [ABSTRACT FROM AUTHOR]

This paper explores the important impact of Fe 2 O 3 on the synthesis, structure, hardness, and radiation shielding characteristics of Apatite–Wollastonite (AW) glass ceramics for bone implantation and shielding application. The prepared studied samples were prepared and the effects of Fe 2 O 3 addition on the synthesis process, density, and different physical and structural parameters comprehensively investigated. Additionally, the radiation shielding properties were determined by using PHITS simulation code and XCOM calculations for all samples. The results reveal that there is a significant impact of Fe 2 O 3 addition on density, hardness, and radiation shielding of AW glass ceramics. The Vickers hardness values were calculated as 547, 598, and 621 Hv in measurements under 0.1 kg load., the density values are found to be as 2.87, 3.07 and 3.28 g/cm3 for AW, Aw -1Fe, and Aw -2Fe, respectively. The highest linear attenuation coefficient in the AW- 2Fe is 0.096 cm−1, Aw -1Fe showed 0.084 cm−1 and AW gave 0.072 cm−1 at 6 MeV. This study underscores the pivotal role of Fe 2 O 3 as a multifaceted modifier in tailoring the properties of AW glass ceramics for bone implantation and other diverse applications extending from medical imaging to radiation and charged ions shielding. [ABSTRACT FROM AUTHOR]

The gamma shielding parameters of an admixture of waste borosilicate glass (BS) and geopolymer (GP) made from activated metakaolin are presented in the present study. The influence of the BS quantity on the density and different gamma shielding quantities is investigated over a wide gamma energy range. Four batches of the G-BS composite were prepared using the solid-state diffusion method, containing 0 (G), 10 % (G-10BS), 20 % (G-20BS), and 30 % (G-30BS) by weight of BS, respectively. The chemical compositions of the G-xBS samples were determined through X-ray fluorescence spectrometry. In addition, the density of the BS-doped geopolymers was determined using the liquid displacement method using deionized water as the displacement fluid. The theoretical determination of estimating shielding parameters began by estimating the mass (μ ρ) and linear (μ) attenuation coefficients of the geopolymers for photon energies in the range of 15 keV to 15 MeV using the XCOM data library. The B and Si content and density of the geopolymer samples increased as the BS weight proportion increased in the geopolymer. The values of the attenuation coefficients (ACs) decreased with energy. For μ, the decrease was from 9.1533 to 0.0355 cm−1, 6.7486 to 0.0374 cm−1, 10.2964 to 0.0396 cm−1, and 10.7722 to 0.0414 cm−1, while for μ ρ , it was 5.3217 to 0.0206 cm2 g-1, 5.3860 to 0.0206 cm2 g-1, 5.3627 to 0.0206 cm2 g-1, and 5.3594 to 0.0206 cm2 g-1, for G, G-10BS, G-20BS, and G-30BS, respectively. There are no significant differences between the photon energy absorption capacity of the geopolymers, especially at energies greater than 1 MeV. The photon buildup factors of the G-xBS samples have very close relative values with no clear order. The introduction of waste borosilicate glass is therefore a way of improving the photon attenuation capacity of geopolymer and, therefore, the potential of shielding applications of geopolymer-based concrete. [ABSTRACT FROM AUTHOR]

The remarkable ability of natural proteins to conduct electricity in the dry state over long distances remains largely inexplicable despite intensive research. In some cases, a (weakly) exponential length‐attenuation, as in off‐resonant tunneling transport, extends to thicknesses even beyond 10 nm. This report deals with such charge transport characteristics observed in self‐assembled multilayers of the protein bacteriorhodopsin (bR). ≈7.5 to 15.5 nm thick bR layers are prepared on conductive titanium nitride (TiN) substrates using aminohexylphosphonic acid and poly‐diallyl‐dimethylammonium electrostatic linkers. Using conical eutectic gallium‐indium top contacts, an intriguing, mono‐exponential conductance attenuation as a function of the bR layer thickness with a small attenuation coefficient β ≈ 0.8 nm−1 is measured at zero bias. Variable‐temperature measurements using evaporated Ti/Au top contacts yield effective energy barriers of ≈100 meV from fitting the data to tunneling, hopping, and carrier cascade transport models. The observed temperature‐dependence is assigned to the protein‐electrode interfaces. The transport length and temperature dependence of the current densities are consistent with tunneling through the protein–protein, and protein‐electrode interfaces, respectively. Importantly, the results call for new theoretical approaches to find the microscopic mechanism behind the remarkably efficient, long‐range electron transport within bR. [ABSTRACT FROM AUTHOR]

Two‐directional beam‐tracking (2DBT) is a method for phase‐contrast imaging and tomography that uses an intensity modulator to structure the X‐ray beam into an array of independent circular beamlets that are resolved by a high‐resolution detector. It features isotropic spatial resolution, provides two‐dimensional phase sensitivity, and enables the three‐dimensional reconstructions of the refractive index decrement, δ, and the attenuation coefficient, μ. In this work, the angular sensitivity and the spatial resolution of 2DBT images in a synchrotron‐based implementation is reported. In its best configuration, angular sensitivities of ∼20 nrad and spatial resolution of at least 6.25 µm in phase‐contrast images were obtained. Exemplar application to the three‐dimensional imaging of soft tissue samples, including a mouse liver and a decellularized porcine dermis, is also demonstrated. [ABSTRACT FROM AUTHOR]

Although lead is a very good radiation shielding material, its toxicity has led researchers to find alternative materials instead of it. Moreover, as the use of Kapton polyimide (PI) film in nuclear power plants and space exploration increases, the need to reveal the radiation degradation properties of this material has come along. In this regard, in the present study, it is aimed to determine the mass and linear attenuation coefficients, half value layer, tenth value layer, mean free path and radiation protection efficiency attenuation parameters for this material, experimentally and theoretically, by using the gammas of the 133Ba radioisotope. Experimental gamma attenuation measurements were made by a spectrometer using a Hamamatsu multi pixel photon counter device with a silicon photomultiplier sensor. The constant fraction discrimination timing method was used to reduce the electronic noise of the spectrometer. The attenuation parameters determined experimentally by following two ways were compared with the theoretical ones obtained from the XCOM program. [ABSTRACT FROM AUTHOR]

The present study deals with fabricating and characterizing glass fiber reinforced epoxy composites with heavy mineral filler (magnetite particles) for potential low-energy radiation shielding applications. The composite materials were fabricated by the hand layup method. Glass/epoxy composite was used as control sample, and radiation shielding composites were manufactured by mixing 20 and 30% (by weight) magnetite particles with epoxy resin. It was revealed that the tensile properties of the magnetite-modified composites were increased, and the composites containing 30% filler exhibited maximum improvement than the control ones. Further assessment of the composite samples was performed by DMA (Dynamic Mechanical Analysis), TGA (Thermogravimetric Analysis), FTIR (Fourier-Transform Infrared) spectroscopy, water uptake (%), and SEM (Scanning Electron Microscopy) testing. The radiation shielding ability of the control and filler-modified composites was assessed by using a gamma (γ) radiation source (60Co). Then, the shielding efficiency was characterized by radiation-reduced intensity (%), LAC (Linear Attenuation Coefficient), MAC (Mass Attenuation Coefficient), HVL (Half Value Layer), TVL (Tenth Value Layer), and SVL (Sixteenth Value Layer). It was revealed that the 30% magnetite filler content composite experienced relatively good attenuation performance against γ-ray than other studied composites. [ABSTRACT FROM AUTHOR]

Gamma-ray, charged particles and neutron-shielding properties of ternary alloy materials, (97.3 – x) Pb – x Cd – 2.7Ag (x = 10, 18 and 30) have been theoretically investigated. First, the effectiveness of gamma-ray shielding for the alloys was studied by using the Phy-X/PSD programme. Mass and linear attenuation coefficients (MAC and LAC), half-value layer (HVL), tenth-value layer (TVL), mean free path (MFP), effective atomic numbers (Zeff), effective electron densities (Neff) and effective conductivity (Ceff) were calculated for photon energy range 0.015–15 MeV. Second, the mass stopping powers (MSPs; dE/ρdx; MeVcm2/g) and ranges for electron, proton and alpha particle interactions were calculated at energy 0.01–20 MeV. Finally, the removal cross-section of fast neutron (FNRCS) for the alloys was calculated by the partial density method. Moreover, the neutrons and gamma-rays shielding effectiveness of ternary alloys were investigated using Monte Carlo (MCNP4b). The MCNP4b calculations were performed for neutrons in the energies 4 and 4.5 MeV. While the shielding parameters of gamma rays were done in the energy range of 0.015–15 MeV. The obtained results of radiation shielding showed that the P1 sample owns a good shielding effectiveness against neutrons and gamma rays compared to previously published studies. The comparison of the computed values has revealed a reasonable agreement between Phy-X/PSD and MCNP4b. This study gives essential data for potential applications of these materials in nuclear reactor core design and other industries for the evaluation of effective ionising radiation shielding materials. [ABSTRACT FROM AUTHOR]

A refined analytical model of spatially resolved diffuse reflectance with small source-detector separations (SDSs) for the in vivo skin studies is proposed. Compared to the conventional model developed by Farrell et al., it accounts for the limited acceptance angle of the detector fiber. The refined model is validated in the wide range of optical parameters by Monte Carlo simulations of skin diffuse reflectance at SDSs of units of mm. Cases of uniform dermis and two-layered epidermis-dermis structures are studied. Higher accuracy of the refined model compared to the conventional one is demonstrated in the separate, constraint-free reconstruction of absorption and reduced scattering spectra of uniform dermis from the Monte Carlo simulated data. In the case of epidermis-dermis geometry, the recovered values of reduced scattering in dermis are overestimated and the recovered values of absorption are underestimated for both analytical models. Presumably, in the presence of a thin mismatched topical layer, only the effective attenuation coefficient of the bottom layer can be accurately recovered using a diffusion theory-based analytical model while separate reconstruction of absorption and reduced scattering fails due to the inapplicability of the method of images. These findings require implementation of more sophisticated models of light transfer in inhomogeneous media in the recovery algorithms. [ABSTRACT FROM AUTHOR]

Noninvasive evaluation of metabolic dysfunction-associated fatty liver disease (MAFLD) using ultrasonography holds significant clinical value. The associations between ultrasound (US)-based parameters and the pathological spectra remain unclear and controversial. This study aims to investigate the associations thoroughly. The participants with MAFLD undergoing liver biopsy and multiparametric ultrasonography were prospectively recruited from December 2020 to September 2022. Three US-based parameters, namely attenuation coefficient (AC), liver stiffness (LS) and dispersion slope (DS) were obtained. The relationship between these parameters and steatosis grades, inflammation grades and fibrosis stages was examined. In this study with 116 participants, AC values significantly differed across distinct steatosis grades (p < 0.001), while DS and LS values varied among inflammation grades (p < 0.001) and fibrosis stages (p < 0.001). The area under the receiver operating characteristic curves (AUCs) of AC ranged from 0.82 to 0.84 for differentiating steatosis grades, while AUCs of LS ranged from 0.62 to 0.76 for distinguishing inflammation grades and 0.83–0.95 for discerning fibrosis stages. AUCs for DS ranged from 0.79 to 0.81 in discriminating inflammation grades and 0.80–0.88 for differentiating fibrosis stages. Subgroup analysis revealed that LS demonstrated different trends in inflammation grade but consistent trends in fibrosis stage across subgroups, whereas DS showed consistent trends for both inflammation grade and fibrosis stage across all subgroups. AC values indicate the degree of hepatic steatosis but not inflammation or fibrosis. LS values are determined only by fibrosis stage and are not associated with inflammation grades. DS values are associated with both fibrosis and inflammation grades. [ABSTRACT FROM AUTHOR]

Radiation shielding materials are essential for balancing the benefits and risks of ionizing radiation. In this prospective, we have prepared a series of glasses with composition (70-x)B 2 O 3 –15BaO–10PbO–5WO 3 -xBi 2 O 3 (where x = 0, 5, 10, 15, 20 mol %) for varying concentrations of Bi 2 O 3 using melt-quenching method. Their physical, thermal, structural, mechanical, optical, and radiation shielding properties were evaluated. XRD scans confirm the amorphous nature of prepared glasses. As Bi 2 O 3 content increases from 0 to 20 mol%, the density of the glasses rises from 3.155 to 4.578 g/cm3. Thermal studies show enhanced properties when substituting B 2 O 3 with Bi 2 O 3. FTIR studies reveal the presence of BO 3 , BO 4 , BiO 3 , and BiO 6 structural units in the glasses. Mechanical properties, evaluated by Makishima–Mackenzie model, decrease as Bi 2 O 3 concentration rises. Optical absorption studies suggest decreasing band gap energy (2.908–2.254 eV for indirect transitions), implying the possibility of the non-bridging oxygen formation. In the context of radiation shielding, mass attenuation coefficients (MAC) of the produced glasses were determined both experimentally and by using the Phy-X/PSD program, and their agreement validates the accuracy of the experimental findings. Additionally, various other shielding parameters such as linear attenuation coefficient (LAC), half value layer (HVL), tenth value layer (TVL), mean free path (MFP), and effective atomic number (Z eff) have been evaluated and interpreted. The results indicate that the substitution of Bi 2 O 3 directly impacts the shielding ability of the glasses. The BBi-20 glass sample, containing 20 mol% of Bi 2 O 3 , emerges as the superior candidate for shielding, showing the highest MAC (0.1284 and 0.0986 cm2/g at the energies 0.511 MeV and 0.662 MeV respectively), LAC, and Z eff , along with minimum HVL, TVL, and MFP values. Comparison of MAC values with standard shielding materials confirms the potential of the produced glasses for gamma shielding applications, highlighting their promising structural and optical properties. [ABSTRACT FROM AUTHOR]

Using a melt quenching procedure, bario-borate sodium glasses with varying concentrations of manganese ions (60B2O3-20NaF-(20-x)BaO-XMnO, where X = 0 (Mn-0.0) − 0.5 (Mn-0.5%mol%) were created. The impact of manganese ions on the structural, physical, radiation shielding, and dielectric properties of the Mn-X samples was examined. X-ray diffraction measurements confirmed that Mn-X samples were in an amorphous state. The measured density (ρ) slightly decreased upon the addition of MnO. In the low-frequency interval, the dielectric constant (ε′) declined significantly as the frequency increased. As the MnO content rose to 0.2 mol%, the ε′ value was clearly decreased, but, at higher concentrations, it increased. The glass specimen that had been modified by 0.2 MnO had the lowest dielectric constant, making it a suitable option for packing materials. The tan δ of the examined glasses displayed relaxation peaks. The ability of the prepared glasses as γ-ray shields was investigated using Phy-X/PSD software. The linear attenuation coefficient (LAC) of the proposed Mn-X glasses followed the order: Mn-0.0LAC > Mn-0.1LAC > Mn-0.2LAC > Mn-0.3LAC > Mn-0.4LAC > Mn-0.5LAC. The observed LAC trend can be explained by the glasses being less dense as the MnO component rises. The half-value layer (HVL) followed the trend: Mn-0.0HVL < Mn-0.1HVL < Mn-0.2HVL < Mn-0.3HVL < Mn-0.4HVL < Mn-0.5HVL. The tenth-value layer (TVL) has the same trend as the HVL. The effective atomic number (Zeff) and effective electron density (Neff) for all the proposed Mn-X glasses have the same trend. The Mn-0.0 glasses are located at the mid-point or at a suitable point among the commercial concrete materials as γ-ray shields. [ABSTRACT FROM AUTHOR]

The radiation shielding properties of different samples of borate-tellurite glass were investigated using WO3 modifiers. Geometric optimization and modification of pristine borate-tellurite with WO3 were carried out based on density functional theory calculations using plane wave basis sets and pseudo-potentials. It was observed that the changes in the physical properties of the white box testing glass (WBTG) systems were determined by WO3 content. Analysis of the linear attenuation coefficient of the sampled glasses, which yielded a value of 7.43 cm for WBTG1 at 20 keV, indicated that WBTG1 was able to stop gamma radiation from Cs-137 and Th-237 sources. Both the µ and µm values were zero above 0.15 MeV, indicating that the WBTG composite was only able to attenuate low-energy photons such as gamma rays. It was found that the characteristic behavior of the WBTG was generally determined primarily by oxygen content, which is in good agreement with theoretical and experimental data. [ABSTRACT FROM AUTHOR]

This work investigates the significant effects of SrO on the structural, physical, and UV–visible (UV–Vis) characteristics and the γ-ray and neutron shielding ability of samarium sodium borotellurite glasses with the composition (46.5-X)B2O3 + 0.5Sm2O3 + 15TeO2 + 18Bi2O3 + 20Na2O + XSrO, where X = 0 (SrO0)–12 (SrO12)% with steps of 3 mol.%, designated as SrOX. The glass samples were prepared via the well-known melt quenching technique. The amorphous nature of the fabricated glasses was confirmed by XRD. The density (ρ) of the SrOX samples increased gradually from 3.73 ± 0.01 g/cm3 to 4.04 ± 0.01 g/cm3. The direct optical gap increased from 2.94 ± 0.01 eV to 2.98 ± 0.01 eV, and the indirect gap increased from 2.74 ± 0.01 eV to 2.95 ± 0.01 eV. Several absorption peaks were found for 4f5–4f5 electronic transitions from ground manifold 6H5/2 to excited samarium ion manifold states. The free volume (Vf), packing density (Pd), ion concentration (N), polaron radius (rp), internuclear distance (ri), field strength (F), molar volume of the boron atoms (Vb), and average boron–boron distance (dBB) changed significantly as the SrO concentration varied in the glass network. The linear attenuation coefficient (µ) followed the order: SrO0 < SrO3 < SrO6 < SrO9 < SrO12. The synthesized SrO12 glass sample had the lowest half-value layer (HVL). The fast neutron removal cross-section (FCS) values of the SrOX glass samples were 0.085 cm−1, 0.085 cm−1, 0.085 cm−1, 0.086 cm−1, and 0.086 cm−1 for samples SrO0, SrO3, SrO6, SrO9, and SrO12, respectively. The obtained results showed that the proposed compositions can be used in optical applications as well as γ-ray and neutron shielding materials. [ABSTRACT FROM AUTHOR]

AbstractBackgroundMethods and findingsConclusionAbbreviationsHepatitis C virus (HCV) is a major cause of chronic liver disease, in which liver stiffness increases. Liver stiffness measurements (LSM) are therefore essential in diagnosing liver diseases and predicting disease development. The study objective was to perform a comprehensive prospective assessment of the liver before, after and 4 years after treatment for HCV, including an assessment of the long-term outcome of fibrosis, steatosis and inflammation.Patients eligible for HCV treatment were included prospectively in 2018 (n = 47). Liver stiffness was measured using transient elastography and 2D shear-wave elastography (SWE). Blood tests, B-mode ultrasound (US) and SWE, were performed before, after (end of treatment [EOT]), 3 months after (EOT3) and 4 years after treatment (4Y). At the final visit, we added attenuation imaging and shear-wave dispersion slope (SWDS) measurements to assess steatosis and inflammation. Three months after treatment, the sustained virologic response rate was 93%. The median liver stiffness for baseline, EOT, EOT3 and 4Y was 8.1, 5.9, 5.6 and 6.3 kPa, respectively. There was a significant reduction in liver stiffness from baseline to EOT, and from EOT to EOT3. After 4 years, the mean attenuation coefficient (AC) was 0.58 dB/cm/MHz, and the mean SWDS value was 14.3 (m/s)/kHz.The treatment for HCV was highly effective. Measurements of liver stiffness decreased significantly after treatment and remained low after 4 years. AC measurements indicated low levels of liver steatosis. Shear-wave dispersion values indicated inflammation of the liver, but the clinical implication is undetermined and should be explored in larger studies.Clinicaltrials.gov: NCT03434470AC: attenuation coefficient; APRI: aspartate aminotransferase to platelet ratio index; ATI: attenuation imaging; cACLD: compensated advanced chronic liver disease; CAP: controlled attenuation parameter; FIB-4: Fibrosis-4 Index for liver fibrosis; HCC: hepatocellular carcinoma; LSM: liver stiffness measurement; NAFLD: non-alcoholic fatty liver disease; NASH: non-alcoholic steatohepatitis; SWDS: shear-wave dispersion slope; SWE: shear-wave elastography; US: ultrasound [ABSTRACT FROM AUTHOR]

The attenuation of slow shear acoustic waves in the (110) plane of tellurium dioxide (TeO2) crystals was investigated. The strong acoustic anisotropy of TeO2 crystals results in a non-uniform acoustic power distribution, which can introduce errors in conventional acousto-optic testing methods. In this study, we propose a general method to measure the acoustic power distribution along the propagation direction of acoustic waves in non-collinear acousto-optic tunable filters (AOTFs). Additionally, we analyze the errors introduced by the non-uniform acoustic field resulting from strong acoustic anisotropy in acousto-optic testing methods. The measurements were carried out for a crystal cutoff angle of 6.5° from the [110] axis, for the ultrasound frequency range from 40 to 140 MHz. The attenuation coefficients were determined and their quadratic dependence on ultrasound frequency was confirmed. [ABSTRACT FROM AUTHOR]

The project's goal is to create new, low-cost materials with low density that can withstand the transport of γ-photons with low and intermediate energy. As a result, a set of four epoxy resins reinforced with different amounts of heavy metallic debris were created. By enlarging the waste component of the manufactured composites by 0–40 wt%, the density of the composites increased from 1.134 ± 0.022 to 1.560 ± 0.0312 g/cm3. The experimental assessment of the linear attenuation coefficient shows an increase with factors of 6.6, 2, and 1.5 times, respectively, for—photon energies of 33, 121, and 662 keV. The augmentation composites density has an impact on these parameters. The half-value thickness and the transmission factor for the fabricated composites decreased with enriching the heavy metallic waste composition, where the half-value thickness decreased from 5.95 to 3.08 cm as well as the transmission factor decreased from 89.01 to 79.86% with enriching the heavy metallic waste concentration from 0 to 40 wt%. The study shows the invalidity to use the fabricated samples to attenuate the γ-photons with energies higher than 662 keV, where the linear attenuation coefficient enhanced by a factor of 19% from 0.078 to 0.094 cm−1. [ABSTRACT FROM AUTHOR]

Background Objective Methods Results Conclusions Current photon‐counting computed tomography (CT) systems utilize semiconductor detectors, such as cadmium telluride (CdTe), cadmium zinc telluride (CZT), and silicon (Si), which convert x‐ray photons directly into charge pulses. An alternative approach is indirect detection, which involves Yttrium Orthosilicate (YSO) scintillators coupled with silicon photomultipliers (SiPMs). This presents an attractive and cost‐effective option due to its low cost, high detection efficiency, low dark count rate, and high sensor gain.This study aims to establish a comprehensive quantitative imaging framework for three‐energy‐bin proof‐of‐concept photon‐counting CT based on YSO/SiPM detectors developed in our group using multi‐voltage threshold (MVT) digitizers and assess the feasibility of this spectral CT for material identification.We developed a proof‐of‐concept YSO/SiPM‐based benchtop spectral CT system and established a pipeline for three‐energy‐bin photon‐counting CT projection‐domain processing. The empirical A‐table method was employed for basis material decomposition, and the quantitative imaging performance of the spectral CT system was assessed. This evaluation included the synthesis errors of virtual monoenergetic images, electron density images, effective atomic number images, and linear attenuation coefficient curves. The validity of employing A‐table methods for material identification in three‐energy‐bin spectral CT was confirmed through both simulations and experimental studies.In both noise‐free and noisy simulations, the thickness estimation experiments and quantitative imaging results demonstrated high accuracy. In the thickness estimation experiment using the practical spectral CT system, the mean absolute error for the estimated thickness of the decomposed Al basis material was 0.014 ± 0.010 mm, with a mean relative error of 0.66% ± 0.42%. Similarly, for the decomposed polymethyl methacrylate (PMMA) basis material, the mean absolute error in thickness estimation was 0.064 ± 0.058 mm, with a mean relative error of 0.70% ± 0.38%. Additionally, employing the equivalent thickness of the basis material allowed for accurate synthesis of 70 keV virtual monoenergetic images (relative error 1.85% ± 1.26%), electron density (relative error 1.81% ± 0.97%), and effective atomic number (relative error 2.64% ± 1.26%) of the tested materials. In addition, the average synthesis error of the linear attenuation coefficient curves in the energy range from 40 to 150 keV was 1.89% ± 1.07%.Both simulation and experimental results demonstrate the accurate generation of 70 keV virtual monoenergetic images, electron density, and effective atomic number images using the A‐table method. Quantitative imaging results indicate that the YSO/SiPM‐based photon‐counting detector is capable of accurately reconstructing virtual monoenergetic images, electron density images, effective atomic number images, and linear attenuation coefficient curves, thereby achieving precise material identification. [ABSTRACT FROM AUTHOR]

The radiation shielding effectiveness of multifunctional thermoplastic biodegradable polymer incorporated with different loadings of graphene nanoplatelets (GNPs) was investigated. The bio-nanocomposite, fabricated using an ultrasonication-assisted melt compounding technique, was composed of polylactide, liquid natural rubber, polyaniline, and various amounts of GNPs. The inclusion of GNPs has enhanced the crystallinity and thermal stability of the nanocomposites. Fourier transform infrared results confirmed the presence of all characteristic peaks of nanocomposites' components, yet with no interfacial interaction between GNPs and the neat matrix. Microstructural and mechanical testing showed optimum properties are linked to 0.4 wt% of GNPs. The addition of low-content GNPs revealed a slight variation in shielding features. Despite this result, the 0.8 wt% filled nanocomposite (PLPG4) sample recorded the highest linear attenuation coefficient and lowest half-value layer, while the neat polymer matrix (PLPG0) showed superior mass stopping power against proton and alpha particles at all energies. The dose rate and total macroscopic cross sections for neutrons, which were determined by the Monte Carlo N-Particle eXtended program code, showed negligible change upon adding GNPs. The fast neutron removal cross section (ΣR) was the same (0.093 cm−1) for all nanocomposites. These results indicate the potential capability of current bio-nanocomposites for neutron and proton shielding applications. [ABSTRACT FROM AUTHOR]

Objective To investigate the value of magnetic resonance image-diffusion weighted imaging (MRI-DMI) combined with attenuation imaging (ATI) in the diagnosis of focal nodular lesions < 2 cm in the background of fatty liver. Methods The clinical data of 68 patients with fatty liver complicated with focal nodular lesions < 2 cm were retrospectively analyzed from June 2022 to June 2023 in Huaihe Hospital of Henan University. All patients underwent MRI, pathology and ATI examination. According to the degree of fatty liver disease, 68 patients were divided into severe group (n = 24), moderate group (n = 27) and mild group (n = 17). The apparent diffusion coefficient (ADC) and acoustic attenuation coefficient (AC) values of patients with different focal lesions were compared with clinical data, and the ADC values and AC values of patients with different fatty liver lesions were compared with clinical data, and the correlation was analyzed by Pearson. To analyze the value of MRIDWI combined with AC value in the diagnosis of malignant fatty liver disease with focal nodular disease < 2 cm. Results Pathological diagnosis showed that 41 of the 68 patients were benign and 27 were malignant. There were no significant differences in low density lipoprotein cholesterol (LDL-C), age, triglyceride (TG), sex, total cholesterol (TC) and high density lipoprotein cholesterol (HDL-C) between benign nodule group and malignant nodule group (P > 0.05). There was no difference in TG, age, HDL-C, sex, TC and LDL-C among mild, moderate and severe groups (P > 0.05). The ADC value of malignant nodule group was lower than benign nodule group under different b values (P < 0.05), and the AC value of malignant nodule group was higher than that of benign nodule group (P < 0.05). ADC value under different b values in the severe group was lower than mild and moderate groups (P < 0.05), ADC value under different b values in the moderate group was lower than mild group (P < 0.05), AC value in the severe group was higher than mild and moderate groups (P < 0.05), and AC value in the moderate group was higher than mild group (P < 0.05). ADC values at different b values were negatively correlated with the degree of fatty liver disease (P < 0.05), but not with TG, HDL-C, TC and LDL-C (P > 0.05). AC was positively correlated with the degree of fatty liver disease (P < 0.05), negatively correlated with HDL-C (P < 0.05), but not with TG, TC and LDL-C (P > 0.05). The area under the curve (AUC) values of MRI-DWI, AC and their combination in the diagnosis of fatty liver complicated with focal nodule disease < 2 cm into malignancy were 0.775, 0.773 and 0.909, respectively (P < 0.05), and the AUC value of the combination was higher (P < 0.05). Conclusion MRI-DWI and ATI have important value in the differential diagnosis of benign and malignant lesions of focal nodular lesions < 2 cm in the background of fatty liver, and the combination of MRI-DWI and ATI has higher diagnostic value. [ABSTRACT FROM AUTHOR]

Rice straw is considered an agricultural waste harmful to the environment, which is abundant in most parts of the world. From this point, the present study is devoted to preparing new composites of two types of glue based on rice straw as a plentiful, low-cost matrix. Straw glue samples were prepared by mixing 20% wt. of rice straw with 80% wt. of animal glue (RS-An) and polyvinyl acetate (RS-PVAC) at different thicknesses of 1, 2, and 3 cm. The chemical composition of the prepared samples was identified by energy dispersive X-ray analysis and their morphology was examined using a scanning electron microscope. The mechanical test explored that RS-An and RS-PVAC respectively required a stress of 25.2 and 25.5 MPa before reaching the breaking point. γ-ray shielding performance was analyzed and determined at numerous photon energies from 0.059 to 1.408 MeV emitted from five-point γ-rays sources using NaI (Tl). Linear attenuation coefficient was calculated by obtaining the area under the peak of the energy spectrum observed from Genie 2000 software in the presence and absence of the sample. The experimental results of mass attenuation coefficient were compared with theoretical data of XCOM software with relative deviation ranging from 0.10 to 2.99%. Geant4 Monte Carlo simulation code was also employed to validate the experimental results. The relative deviation of XCOM and Geant4 outcomes was 0.09–1.77%, which indicates a good agreement between them. Other radiation shielding parameters such as half value layer (HVL), tenth value layer, and mean free path were calculated in three ways: experimentally, theoretically from the XCOM database, and by simulation using Geant4 code. Additionally, effective atomic number (Zeff), effective atomic number (Neff), equivalent atomic number (Zeq), and buildup factors were evaluated. It was confirmed that the γ-ray shielding properties were further boosted by mixing rice straw with the animal glue compared to the synthetic one. [ABSTRACT FROM AUTHOR]

Melt quenching technique was used to create Bismuth Boro-Silicate nano glasses with compositions of 45SiO2-10CaO- 25Na2O- xBi2O3- (20-x) B2O3 (where x is 0, 5, 10, 15, and 20 mol %). Standard point sources AM-241, Ba-133, Co-60, Cs-137, and Eu-152 were used in the radiation experiment to evaluate the attenuation coefficients spanning the energy range of 59.51 keV to 1048.01 keV. The findings show that adding Bi2O3 in place of B2O3 increases the following: radiation protection efficiency (RPE%), transmission factor (TF%), absorption buildup factor values (ABF), exposure buildup factor values (EBF), mass attenuation coefficients (MACs), linear attenuation coefficients (LACs), and radiation protection efficiency (RPE%). In comparison to lead glass, these findings demonstrate the potential of nano Bismuth Boro-Silicate glass as a radiation shielding material. [ABSTRACT FROM AUTHOR]

Since X-ray computed tomography (CT) can analyse non-accessible features and parts in a non-destructive way, it enables the inspection of the individual components of assemblies in the assembled state. Such unique inspection capability is of great relevance because, even when each part of an assembly meets the specified tolerances, the proper functioning of the assembled system is not guaranteed, as variations can occur during the assembly operations, for instance due to clamping and/or assembly forces. Besides the dimensional evaluation of components in the assembly state, contact surfaces/interfaces and micro-gaps between coupled assembled components are in many cases important to be accurately identified and measured. These evaluations can be more easily conducted on multi-material assemblies in which the materials of the single components are characterized by different densities and characteristics, thus enabling their mutual distinction and segmentation within the CT reconstructed volume. In the case of mono-material assemblies, instead, due to the single X-ray attenuation coefficient to be considered, the three-dimensional model of the assembly resulting after CT reconstruction would appear as a unique and continuous volume in regions where components are in contact, with serious difficulties in evaluating their interface. To overcome this limit, the present research was aimed at developing new CT-based methods to enable a complete evaluation of mono-material assemblies. Such methods were applied to titanium dental implant systems, for which an accurate analysis of contact surfaces and interfaces between the assembled components is crucial to ensure perfect sealing and prevent mechanical failures as well as microbiological leakage and consequent bacteria infiltrations. Finally, the accuracy of the obtained measurement results is evaluated using a reference object made of titanium, featuring different calibrated micro-gaps. • CT reconstructions of mono-material assemblies appear as a unique and continuous volume. • Evaluating the interface where components are in contact is hence difficult. • Methods are developed to enable CT analyses of contact surfaces in mono-material assemblies. • The methods are applied to titanium dental implant systems. • The results accuracy is determined using a reference object with calibrated micro-gaps. [ABSTRACT FROM AUTHOR]

Focusing on the bending wave characteristic of plate–shell structures, this paper derives the complex band curve of piezoelectric phononic crystal based on the equilibrium differential equation in the plane stress state using COMSOL PDE 6.2. To ascertain the computational model's accuracy, the computed complex band curve is then cross-validated against real band curves obtained through coupling simulations. Utilizing this model, this paper investigates the impact of structural and electrical parameters on the bandgap range and the attenuation coefficient in the bandgap. Results indicate that the larger surface areas of the piezoelectric sheet correspond to lower center bands in the bandgap, while increased thickness widens the attenuation coefficient range with increased peak values. Furthermore, the influence of inductance on the bandgap conforms to the variation law of the electrical LC resonance frequency, and increased resistance widens the attenuation coefficient range albeit with decreased peak values. The incorporation of negative capacitance significantly expands the low-frequency bandgap range. Visualized through vibration transfer simulations, the vibration-damping ability of the piezoelectric phononic crystal is demonstrated. Experimentally, this paper finds that two propagation modes of bending waves (symmetric and anti-symmetric) result in variable voltage amplitudes, and the average vibration of the system decreases by 4–5 dB within the range of 1710–1990 Hz. The comparison between experimental and model-generated data confirms the accuracy of the attenuation coefficient calculation model. This convergence between experimental and computational results emphasizes the validity and usefulness of the proposed model, and this paper provides theoretical support for the application of piezoelectric phononic crystals in the field of plate–shell vibration reduction. [ABSTRACT FROM AUTHOR]

Optical coherence tomography (OCT) is a reliable technique for cancer detection, with the potential to improve accuracy in identifying cancerous tissue through effective use of OCT image data. We proposed an optimized depth resolution estimation based optical attenuation coefficient (OAC) mapping method to reduce the error effect caused by discretization without considering whether the light is completely attenuated or not. The attenuation coefficient maps of gastric tissue were reconstructed using this method. Features were extracted from these maps using gray-level co-occurrence matrix and gray histogram, and a support vector machine was employed as a classifier for identifying gastric cancer tissues. The recognition accuracy achieved was 98.60%, which was higher than the 94.30% accuracy in the control group without OACs. This approach enhances the utilization of OCT image information and improves its practical application ability by increasing the recognition accuracy. [ABSTRACT FROM AUTHOR]

By using the characteristics of two disparate materials (BaTiO $ _3 $ 3 ceramic and PZT-5H ceramic) on SiO $ _2 $ 2 glass, we have analyzed shear horizontal wave (SH wave) propagation through a piezo-visco-elastic composite medium (PVECM). For the better platform of the originality of the situation, the piezo-visco-elastic medium (PVEM) is taken between two elastic materials. The exact solution of the governing equations is obtained and discussed in detail with the variation of various significant parameters. Irregular and irregular free, both boundary conditions are assumed to find relevant results. The influence of viscosity, piezo-electric parameter and dielectric parameter for irregular and irregular free boundaries on SH-wave propagation through BaTiO $ _3 $ 3 ceramic and PZT-5H ceramic materials are shown by some curves. This model contains a huge potential to deal with many commercial and industrial applications. The present investigation has uncovered various crucial results which include for both materials, attenuation coefficient for irregular interface are lower than that of the regular interface. For PZT-5H ceramic material, viscosity, dielectric parameter and piezo-electric parameter have a greater impact on phase velocity and attenuation coefficient in comparison to BaTiO $ _3 $ 3 ceramic. [ABSTRACT FROM AUTHOR]

In this work, we studied the effect of bismuth oxide particle size and its attenuation capacity as a filler additive in epoxy resins. Six samples were prepared according to the amount of microparticles and nanoparticles in the sample and were coded as ERB-1, ERB-2, ERB-3, ERB-4, ERB-5, and ERB-6. One of the composite epoxies contained Bi2O3 microparticles at a 50:50 ratio (ERB-6) and was chosen as the control composite, and the number of microparticles (MPs) was gradually decreased and replaced by nanoparticles (NPs) to produce epoxy-containing Bi2O3 nanoparticles at a 50:50 ratio (ERB-1). The morphological and thermal characteristics of the studied composites were tested. The attenuation capability of the prepared composites, which is determined by the Bi2O3 particle size, was determined experimentally using a semiconductor detector, an HPGe-detector, and three different gamma-ray point sources (Am-241, Co-60, and Cs-137). The linear attenuation coefficient (LAC) of ERB-3, which contained 30% nanoparticles and 20% microparticles, had the highest value compared to the other composites at all the energies discussed, while the ERB-6 composite had the lowest value at all energies. The radiation-shielding efficiency (RSE) of the prepared samples was determined at all discussed energies; at 662 keV, the radiation-shielding efficiency values were 15.97%, 13.94%, and 12.55% for ERB-3, ERB-1, and ERB-6, respectively. The statistics also proved that the attenuation capacities of the samples containing a combination of nanoparticles and microparticles were much superior to those of the samples containing only microparticles or nanoparticles. A ranking of the samples based on their attenuation capacity is as follows: ERB-3 > ERB-4 > ERB-2 > ERB-1 > ERB-5 > ERB-6. [ABSTRACT FROM AUTHOR]

This study involved the preparation of natural rubber-based composites incorporating varying proportions of heavy metals and rare earth oxides (Sm2O3, Ta2O5, and Bi2O3). The investigation analyzed several parameters of the samples, including mass attenuation coefficients (general, photoelectric absorption, and scattering), linear attenuation coefficients (μ), half-value layers (HVLs), tenth-value layers (TVLs), mean free paths (MFPs), and radiation protection efficiencies (RPEs), utilizing the Monte Carlo simulation software Geant4 and the WinXCom database across a gamma-ray energy spectrum of 40–150 keV. The study also compared the computational discrepancies among these measurements. Compared to rubber composites doped with single-component fillers, multi-component mixed shielding materials significantly mitigate the shielding deficiencies observed with single-component materials, thereby broadening the γ-ray energy spectrum for which the composites provide effective shielding. Subsequently, the simulation outcomes were juxtaposed with experimental data derived from a 133Ba (80 keV) γ-source. The findings reveal that the simulated results align closely with the experimental observations. When compared to the WinXCom database, the Geant4 software demonstrates superior accuracy in deriving radiation shielding parameters and notably enhances experimental efficiency. [ABSTRACT FROM AUTHOR]

Purpose: It has been reported that the estimate of ultrasound attenuation coefficient (AC) is affected by depth of measurement, with linear decrease of values with depth. It is unknown whether backscatter coefficient (BSC) has similar behavior. Methods: This retrospective study was performed with Sequoia US system equipped with ultrasound derived fat fraction (UDFF) algorithm (Siemens Healthineers, Issaquah, WA, USA) that combines BSC with AC. UDFF was obtained positioning upper edge of the region of interest at 1.5,2,3,4,5 cm below liver capsule. BSC data were extracted from UDFF offline. A fractional polynomial regression, which selects the best model considering the polynomial development of the variables of interest, was used. Covariates included were age, sex, skin-to-liver-capsule distance, stiffness. Distance was included as linear factor or with a power ranging from − 2 to 3, and the best fitting model was chosen according to partial F test. Body mass index (BMI) was not included because of collinearity with skin-to-liver capsule distance. Results: 104 individuals (56 females; age: 57.9 ± 13.0 years; BMI: 29.0 ± 6.5 kg/m2; skin-to-liver-capsule distance: 2.3 ± 0.7 cm; liver stiffness: 7.5 ± 5.5 kiloPascal) were studied. Best fitting model for BSC included a combination of depth as linear factor and square root. BSC showed a decrease of − 13.98 dB/cm-steradian for each logarithmic increase of 1 cm depth (coefficient: − 13.98; 95% CI: − 21.016; − 5.379; p =.001). Skin-to-liver-capsule distance and stiffness also were independent predictors of BSC. Conclusions: The estimation of the BSC in the liver exhibits a depth dependence that significantly affects results. A standardized acquisition protocol is needed to compare results and reliably assess changes over time. [ABSTRACT FROM AUTHOR]

This study focused on developing microstructural, thermal, and radiation shielding changes in Al50Si25B25 powders using mechanical alloying techniques. Based on the x‐ray powder diffraction data, the crystallite size and microstrain of the 100‐hours milled powder were calculated as 0.25 nm and 50.33 %, respectively. The solubility of silicon in the α‐aluminium matrix increased with longer mechanical alloying duration. Transmission electron microscope analyses further showed that the alloy particulates had an average size of 3 μm and an average grain size of 0.226 nm. The radiation shielding properties of the Al50Si25B25 powders indicated that the Linear Attenuation Coefficient value increased from 0.0554±0.1689 cm−1 to 1.0632±0.2425 cm−1 with an increase in the thickness of the Al50Si25B25 alloy. This work successfully demonstrated the potential of mechanical alloying techniques to enhance the microstructural and thermal properties of Al50Si25B25 powders. It highlighted their effectiveness in providing radiation shielding capabilities when varying the thickness of the alloy. [ABSTRACT FROM AUTHOR]

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has promoted the development of this document on multiparametric ultrasound. Part 2 is a guidance on the use of the available tools for the quantification of liver fat content with ultrasound. These are attenuation coefficient, backscatter coefficient, and speed of sound. All of them use the raw data of the ultrasound beam to estimate liver fat content. This guidance has the aim of helping the reader in understanding how they work and interpret the results. Confounding factors are discussed and a standardized protocol for measurement acquisition is suggested to mitigate them. The recommendations were based on published studies and experts' opinion but were not formally graded because the body of evidence remained low at the time of drafting this document. [ABSTRACT FROM AUTHOR]

Assuming different types of imperfect interfaces composed of a magnetoelectroelastic (MEE) structure, the current work investigates the transmission of a Love-type wave in a MEE solid cylindrical structure. The spatially variable quasi-classical technique is applied to derive the analytical solution of the layers. The substantial impact of factors related to the imperfect interface on the wave phase velocities is illustrated numerically. The Love-type wave's dispersion relation has been established as the determinant for electrically and magnetically open and short cases. Moreover, the article investigates the consequences of six different imperfect parameters namely mechanical imperfection, electrical imperfection, magnetic imperfection, magneto-mechanical imperfection, electro-mechanical imperfection, and magneto-electrical imperfection parameters in magnetically and electrically open and short scenarios are covered. The findings demonstrate that, in comparison to the short case, the electric and magnetic open case has a higher phase velocity. Here are some key findings: imperfection parameters strongly affect the phase velocity and attenuation coefficient curves and the bonding parameter's prominent influence is inversely proportional to the attenuation coefficient and well-proportional to the phase velocity. Identifying the piezoelectric and piezomagnetic connection and its possible use in the construction of sensors, actuators, energy harvesters, and nano-electronics is the result of this theoretical investigation. This is the first time that a polar coordinate system was used in the quasi-classical method of solving differential equations. The results argue that the outcomes of this specific model have an immense ability to deal with various commercial and industrial applications in acoustical engineering, geotechnical design, ultrasonic technology, and SAW devices. [ABSTRACT FROM AUTHOR]

Advanced ultrasound techniques were used to study liquid–liquid dispersed flows formed in impinging jets confined in small channels. Ultrasound speed and attenuation coefficient spectra of the propagated sound waves were used to obtain volume fraction and drop size distributions, respectively. The results were compared against drop size distributions obtained with high-speed imaging. Experiments were conducted in a 2 mm internal diameter tube for both kerosene oil continuous and glycerol/water continuous dispersions. The overall mixture flow rate was set at 60 ml/s, and the dispersed phase fractions were 0.02, 0.05, and 0.10. The measured volume fractions were found to be very close to the input ones, indicating a very small slip between the phases in the dispersed flows. From the ultrasound measurements, the drop size distributions were found to range from 32 to 695 μm under the different conditions used. The drop sizes at the two low input volume fractions were in reasonable agreement with the results from the imaging. Imaging, however, could not be used for the 0.10 input dispersed phase fraction. These results demonstrate the applicability of the ultrasound techniques to measurements in dispersed liquid–liquid flows in small channels. [ABSTRACT FROM AUTHOR]

Libraries of inherent optical properties (IOPs) of microplastics are sparse, yet they are essential for the development of optical techniques to detect and quantify microplastics in the ocean. In this study, we describe our results and technique for the measurement of the IOPs of microplastic suspensions generated from commonly utilized plastics. The measurements included angle‐resolved polarized light scattering, and spectral absorption and beam attenuation coefficients. We also performed ancillary characterization of particle properties, including size distribution, shape, and mass concentration of suspended matter. We observed several unique optical characteristics regarding absorption, scattering, and polarization properties compared with typical marine particle assemblages. We show that these results are useful for radiative transfer simulations as well as the potential development of novel plastic detection techniques from above‐ or in‐water optical measurements. [ABSTRACT FROM AUTHOR]

Double perovskites are emergent materials because of their exciting characteristics, such as their stable crystal structure. Thermoelectric, optical, structural, elastic, electrical, magnetic, and perovskite Rb2FeCdO6 properties are explored within the framework of spin-polarized density functional theory, all computations were carried out using the full-potential linear augmented plane-wave approach. The potential was applied using GGA with an extra onsite Coulomb parameter (GGA + U), including the Hubbard parameter. The phase stability calculation shows that Rb2FeCdO6 should remain stable in a ferromagnetic state and a cubic geometry (space group Fm-3 m). This Rb2FeCdO6 compound is mechanically and chemically stable, as confirmed by the computed formation energy, tolerance factor, and elastic constants. Poisson and Pugh's ratios were used to study ductile and brittle behaviour. Using the GGA + U methods, the results reveal that double perovskite has a semiconductor nature with a magnetic moment of 5.5 µB, as determined by the magneto-electronic characteristics. The band structure calculations show the direct band gap of 2.2 eV (Up) and 1.8 eV (Dn) for Rb2FeCdO6 Double perovskites. The optical properties were also studied in detail, including complex dielectric constants, refractive indices, reflectivity, extinction coefficients, absorption coefficients, and optical conductivity functions up to 13.0 eV. Using the phy-x: PDS program, The mass attenuation coefficient (GMAC), linear attenuation coefficient (GLAC), half value (GHVL), mean free path (GMFP), effective, calculated atomic number (Zeff) were determined gamma radiation shielding properties of Rb2FeCdO6), and the effective electron density (Neff). The study shows that GMAC and GLAC values for Rb2FeCdO6 decrease with increasing photon energy, with a remarkable increase near K-edge absorption due to photoelectric effect dominance at low energy GHVL and GMFP increase with photon energy increases, indicating a decrease in photon interaction. We computed thermoelectric responses to evaluate potential and go into depth about the outcomes of the investigation. The Seebeck coefficient's positive and negative values classify double perovskites as exhibiting n and p-type semiconductors. These materials have high power factor values of 6.0 × 1011 Wm−1 K−2 s−1 and a figure of merit of 0.9, indicating good power conversion efficiency at high temperatures. Our results highlight the compound's potential for optoelectronic and thermoelectric devices. [ABSTRACT FROM AUTHOR]

This work presents an in-depth analysis of the linear attenuation coefficient (LAC), effective atomic number (Zeff) and half value layer (HVL) for borosilicate glasses doped with ZnO. Utilizing Akima splines and piecewise cubic Hermite interpolating polynomials (PCHIP), we predicted the LAC, Zeff and HVL for the investigated glasses in a wide energy range of 0.015–15 MeV. The results showed that the LAC values for the four prepared glasses predicted by Akima splines and PCHIP closely match the theoretical data at all the selected energy levels. This suggested that both Akima splines and PCHIP are a reliable technique for evaluating the LAC of the prepared borosilicate glasses in the energy range of 0.015–15 MeV. The same agreement between the theoretical and predicted data was also reported for the Zeff and HVL. Also, we examined the accuracy in the Akima splines and PCHIP methods in predicting the radiation shielding properties for the selected glasses at certain energy values emitted by Eu-152. The results demonstrated excellent agreement between Akima splines and PCHIP with the theoretical data, which confirms the usefulness of these two interpolation methods in predicting the radiation shielding parameters in the energy range of 0.0395–1.46 MeV. [ABSTRACT FROM AUTHOR]

Yttria-stabilized zirconia (YSZ) oxide ceramic powder is a thermal-barrier material used to fabricate thermal barrier coatings (TBC). In this study, to improve the electromagnetic wave (EMW) absorbing properties of TBCs, microwave-absorbing samarium iron nitrogen (SmFeN) particles were used to prepare SmFeN/yttria-stabilized zirconia (YSZ) composites. To study the effect of the SmFeN/YSZ interfaces on the EMW-absorbing properties of the SmFeN/YSZ composite, SmFeN/YSZ interfaces were built in different ways in composite materials having the same mass ratio of 1:1, for example, SmFeN and YSZ particles homogeneously mixed together, SmFeN/YSZ interfaces perpendicular and parallel to the EMW incident direction, and different interfaces between YSZ and SmFeN. Thus, the microwave absorbing performance of the samples, including the electromagnetic parameters, attenuation coefficient, eddy-loss current (C 0), impedance matching, and minimum reflection loss (RL min) values were examined and analyzed. The results demonstrate that interfaces perpendicular to the direction of the EMWs can increase the contact area and enhance the interfacial absorption effect. Further, when the wave-absorbing agent was placed in the middle of the composite, its wave-absorbing effect was the best among all the samples, yielding RL min = −27.824 dB and effective absorption bandwidth (EAB) = 8.5453 GHz (effective absorption frequency range 7.9256–16.4709 GHz for a 7.2-mm-thick layer). Crucially, the frequency and bandwidth at which the best absorption occurred could be tuned by adjusting the thickness of the coating. This is because the interfaces in the samples resulted in polarization enhancement and anomalous dispersion, leading to large dielectric losses. Overall, the use of a coaxial measurement technique is highly efficient for EMW absorbing body design and process simulations. [ABSTRACT FROM AUTHOR]

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Purpose: The combination of high-pressure air and TNT in shock tubes can effectively simulate real nuclear explosions and conventional weapon explosion shock waves. However, the explosion shock wave parameters are greatly affected by changes in the tube sections and the increase in the initial air pressure. Methods: In this study, the propagation law of explosion shock waves in closed variable section tubes was studied first through theoretical analysis and explosion tests under five different high-pressure environments. Then, the influences of different initial pressures of 100–500 kPa on shock wave related parameters were analyzed by numerical simulation, the change curves of the shock wave overpressure peak and different initial pressures at different test points were fitted, and the change process of the pressure field in the tube was obtained. Finally, an engineering model that can attenuate the shock wave overpressure peak in high-pressure tube with variable section is established by dimensional analysis method. Results: The results show that the attenuation coefficient of the shock wave decreases with an increasing cross section change rate and the related parameters of the shock wave increase with an increasing initial pressure. Compared with normal temperature and pressure, the maximum increase in the peak overpressure of the shock wave is 11.4%, the maximum increase in the arrival time is 94.2%, and the maximum increase in the impulse is 3.5%. Conclusion: The conclusion of this study is that contracting the tube cross-section within the excitation tube driving section can effectively enhance the intensity of the shock wavefront. The combined high-pressure air and explosive driving method can effectively increase the energy of the driving section. Moreover, the higher the initial pressure of air, the higher the energy at the exit of the excitation tube. The results obtained can be used for simulation analysis of explosion shock waves. [ABSTRACT FROM AUTHOR]

Objectives: To assess whether meal or water intake may affect the measurement of the ultrasound (US) attenuation coefficient (AC) imaging, a parameter that is directly related to liver fat content. Methods: The study was performed in two centers (Italy and USA). AC was obtained using the ATI algorithm implemented in the Aplio i‐series US systems (Canon Medical Systems, Japan) by one operator at each center. Measurements were performed at baseline and 5, 15, 30, 45 minutes after drinking 500 mL of water (group 1), or 30, 45, 60, 90, 120 minutes after eating a meal of about 600 kcal (group 2). Multilevel generalized estimating equations for repeated measures were used for the statistical analysis to consider the clustered nature of the data. Results: Twenty‐six individuals were enrolled: 11 (10 females; age, 43.7 ± 12.5 years) in Italy and 15 (10 females; age, 60.7 ± 6.3 years) in USA. At B‐mode US, 10 (38.5%) had liver steatosis. The baseline AC values, in decibel/centimeter/megahertz, were 0.64 (0.12) in group 1 and 0.66 (0.13) in group 2. There was not any significant difference in AC values at every time‐point after water or meal intake either in group 1 or group 2. This result did not change including sex, age, and skin‐to‐liver capsule into the models. Conclusions: The measurement of the AC, which is a biomarker of liver steatosis, does not require a fasting state and drinking water does not affect the result. [ABSTRACT FROM AUTHOR]

This study employs the XBeach surfbeat model (XBSB) to explore the effects of vegetation on wave attenuation and dune erosion in a case study of Mexico Beach during Hurricane Michael. The XBSB model was validated against laboratory experiments of wave-induced dune erosion and wave attenuation by vegetation. In the case study of vegetation on dunes in Mexico Beach during Hurricane Michael, different vegetation drag coefficients were evaluated to investigate the effects of vegetation on wave attenuation and dune erosion. LiDAR data of dune profiles before and after Hurricane Michael were used for model validation. The findings reveal that vegetation on dunes significantly affects wave attenuation and dune erosion. Under vegetated conditions, as the vegetation drag coefficient value increases, wave attenuation also increases, leading to a reduction of dune erosion. An increase in vegetation density enhances wave attenuation in the vegetated area, including reductions in significant wave height and flow velocity. However, the rate of change in attenuation decreases as the vegetation density increases. Through simulations under regular wave condition on Mexico Beach, an optimal vegetation density was identified as 800 units/m2. Beyond this density, additional vegetation does not substantially improve wave attenuation. Furthermore, the position of the dune crest elevation is related to the location where the alongshore flow velocity begins to decrease. The findings highlight the essential role of coastal vegetation in enhancing coastal resilience against hurricanes. [ABSTRACT FROM AUTHOR]

This data paper outlines the development and structure of a synthetic dataset (SD) within the optical domain, encompassing inherent and apparent optical properties (IOPs-AOPs) alongside associated optically active constituents (OACs). The bio-optical modeling benefited from knowledge and data accumulated over the past three decades, resulting on a comprehensive dataset of in situ IOPs, including diverse water typologies, and enabling the imposition of rigorous quality standards. Consequently, the bio-optical relationships delineated herein represent valuable contributions to the field. Employing the Hydrolight scalar radiative transfer equation solver, we generated above-surface and submarine light fields across the specified spectral range at a "true" hyperspectral resolution (1 nm), covering the ultraviolet down to 350 nm, therefore facilitating algorithm development and assessment for present and forthcoming hyperspectral satellite missions. A condensed version of the dataset tailored to twelve Sentinel-3 OLCI bands (400 nm to 753 nm) was crafted. Derived AOPs encompass an array of above- and below-surface reflectances, diffuse attenuation coefficients, and average cosines. The dataset is distributed in 5000 files, each file encapsulating a specific IOP scenario, ensuring sufficient data volume for each water type represented. A unique feature of our dataset lies in the calculation of AOPs across the complete range of solar and viewing zenith and azimuthal angles as per the Hydrolight default quadrants, amounting to 1300 angular combinations. This comprehensive directional coverage caters to studies investigating signal directionality, previously lacking sufficient reference data. The dataset is publicly available for anonymous retrieval via the FAIR repository Zenodo at https://doi.org/10.5281/zenodo.11637178 (Pitarch and Brando, 2024). [ABSTRACT FROM AUTHOR]