Attenuation Coefficient Research Articles

Estimating radial attenuation of vacuum pressure for dredged clays

The radial attenuation of vacuum pressure in dredged clays limits the effectiveness of vacuum consolidation. In this study, a series of model tests were conducted on five dredged clays with varying initial water contents to investigate this radial attenuation. The significant radial attenuation can be divided into two stages: the increasing and stabilization stages. In the stabilization stage, exponential radial attenuation is observed. Lower initial void ratio (e 0) and higher void ratio at liquid limit (e L) lead to a decrease in radial attenuation. Additionally, higher applied vacuum pressure (p v) results in a greater reduction in the magnitude of the radial vacuum pressure. In the increasing stage, the radial vacuum pressure increases exponentially to a stable state after start-up. The radial attenuation is attributed to the differential start-up time (i.e., initial time-point at which the increase begins) and varying increase rates. Lower e 0, higher e L, and higher p v values reduce the start-up time and raise the increase rate. A changing pattern is proposed to describe the exponential radial attenuation using three parameters: radial attenuation coefficient (k 2), increasing coefficient (k 3), and time-delay coefficient (D t). Furthermore, an empirical estimation for the radial attenuation is also suggested without relying on time-consuming tests

An Improved Physics-Based Dual-Band Model for Satellite-Derived Bathymetry Using SuperDove Imagery

Shallow water bathymetry is critical for environmental monitoring and maritime security. Current widely used statistical models based on passive optical satellite remote sensing often rely on prior bathymetric data, limiting their application to regions lacking such information. In contrast, the physics-based dual-band log-linear analytical model (P-DLA) can estimate shallow water bathymetry without in situ measurements, offering significant potential. However, the quasi-analytical algorithm (QAA) used in the P-DLA is sensitive to non-ideal pixels, resulting in unstable bathymetry estimation. To address this issue and evaluate the potential of SuperDove imagery for bathymetry estimation in regions without prior bathymetric data, this study proposes an improved physics-based dual-band model (IPDB). The IPDB replaces the QAA with a spectral optimization algorithm that integrates deep and shallow water sample pixels to estimate diffuse attenuation coefficients for the blue and green bands. This allows for more accurate estimation of shallow water bathymetry. The IPDB was tested on SuperDove images of Dongdao Island, Yongxing Island, and Yongle Atoll. The results showed that SuperDove images are capable of estimating shallow water bathymetry in regions without prior bathymetric data. The IPDB achieved Root Mean Square Error (RMSE) values below 1.7 m and R2 values above 0.89 in all three study areas, indicating strong performance in bathymetric estimation. Notably, the IPDB outperformed the standard P-DLA model in accuracy. Furthermore, this study outlines four sampling principles that, when followed, ensure that variations in the spatial distribution of sampling pixels do not significantly impact model performance. This study also showed that the blue–green band combination is optimal for the analytical expression of the physics-based dual-band model.

Estimation of skin surface roughness in vivo based on optical coherence tomography combined with convolutional neural network.

The texture of human skin is influenced by both external and internal factors, and changes in wrinkles can most directly reflect the state of the skin. Skin roughness is primarily used to quantify the wrinkle features of the skin. Therefore, effective and accurate quantification of skin roughness is essential in skincare, medical treatment, and product development. This study proposes a method for estimating the skin surface roughness using optical coherence tomography (OCT) combined with a convolutional neural network (CNN). The proposed algorithm is validated through a roughness standard plate. Then, the experimental results revealed that skin surface roughness including arithmetic mean roughness and depth of roughness depends on age and gender. The advantage of the proposed method based on OCT is that it can reduce the effect of the skin surface's natural curvature on roughness. In addition, the method is combined with the epidermal thickness and dermal attenuation coefficient for multi-parameter characterization of skin features. It could be seen as a potential tool for understanding the aging process and developing strategies to maintain and enhance skin health and appearance.

Elastic and radiation shielding properties of zinc borotellurite glass systems: The impact of gadolinium oxide

Using the formula [(TeO2)70(B2O3)30], this study examines the impact of Gd2O3 on the elasticity and radiation shielding characteristics of zinc borotellurite glass. Glass samples containing 1–5% mol% Gd2O3 were created by employing the melt quench technique. XRD verified that they are amorphous in nature, and the existence of TeO3, TeO4, BO3, and BO4 vibrational groups was revealed by infrared spectra. The structural alterations were shown by the range of longitudinal and shear ultrasonic velocities, which were 3908–4076 m/s and 2222–2277 m/s, respectively. The glass's rigidity was improved by the large rise in elastic moduli, such as bulk (45 GPa), longitudinal (80 GPa), shear (25 GPa), and Young's moduli (60 GPa), with a higher Gd2O3 content. Higher concentrations of Gd2O3 resulted in a rise in the mass attenuation coefficient (μρ), as measured by WinXcom, which enhanced gamma-ray shielding. The half-value layer (HVL) and mean free path (MFP) at 0.662 MeV decreased with increasing Gd2O3 in a consistent manner. The maximum density and optimum gamma-ray shielding performance were found in the glass containing 5 mol% Gd2O3. These results show Gd2O3 for applications needing greater rigidity and better radiation protection by demonstrating how it affects the elastic and radiation-shielding efficiency of the glass network.

Green synthesized Cr2O3/Bi2O3 nanocomposites for gamma ray shielding

The quest for advanced materials in gamma radiation shielding has spurred the exploration of environmentally friendly, nanotechnology-based approaches. This study introduces a novel synthesis of Cr2O3/Bi2O3 nanocomposites (NCs) using the solution combustion method, with Aloe vera extract serving as a natural reducing agent. Comprehensive analytical characterization of the synthesized NCs was conducted using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), and ultraviolet–visible (UV–Vis) spectroscopy. The gamma radiation shielding properties of the Cr2O3/Bi2O3 NCs are evaluated using a NaI(Tl) detector connected to a multichannel analyzer. Key shielding parameters, including mass attenuation coefficients, mean free path, half-value layer, tenth-value layer, energy buildup factor, and radiation protection efficiency, indicate that Cr2O3/Bi2O3 NCs are highly effective in gamma radiation shielding. The results demonstrated the feasible shielding performance of these nanocomposites across various energies within error limits of 5 %. This study highlights the potential of Cr2O3/Bi2O3 NCs as a promising, sustainable alternative to conventional shielding materials, offering enhanced gamma radiation protection with reduced environmental impact.

Investigating radiation shielding parameters for X-ray attenuation at various energies in locally produced ceramic materials used in Saudi Arabia

To assess shielding effectiveness against X-rays, a number of locally collected ceramic samples were obtained from the Kingdom of Saudi Arabia. Based on elemental analysis, all of the ceramic samples have a density in the range of 1.68–1.85 g/cm3, with the highest proportions of O, Si, C, and Al atoms and the lowest amounts of Na, Mg, K, Ca, Ti, and Fe. The 320 kV X-ray source (Gulmay Limited, Byfleet, UK) was used to assess the attenuation properties of the ceramic samples. An Exradin A4 ionization chamber (Standard Imaging, Middleton, USA) connected to a UNIDOS electrometer (PTW, Freiburg, Germany) in the control room was used to detect the attenuation properties. Several X-ray attenuation coefficients are evaluated at different X-ray energies in the range of 40–150 kV in this study. These include the mass attenuation coefficient (MAC), linear attenuation coefficient (LAC), half-value layer (HVL), tenth-value layer (TVL), and mean free path (MFP). The ability of any ceramic sample under investigation to shield radiation at low X-ray energy is indicated by the theoretical and experimental values of LAC. The potential applications of these easily accessible, reasonably priced ceramic materials for radiation protection in X-ray labs and low-energy X-ray shielding in a variety of fields have been shown by this investigation.

A comprehensive study of radiation shielding parameters of chalcogens-rich quaternary alloys for nuclear waste management

The current study examines the impact of metal additives on the shielding characteristics of Se76Te20Sn2M2 (where M = Ge, In, Sb, and Pb). These glasses are useful as shielding materials against high-energy radiation, such as X-rays and ϒ-rays, because these glasses have better values of shielding parameters compared to other potential candidates in the race for nuclear safety applications. To this end, we have calculated various radiation-related protection parameters using an online application called Phy-X/PSD. Using this program, we have estimated a complete list of radiation shielding parameters. The impact of the fourth element M (M = Ge, In, Sb, and Pb) on these parameters is also discussed.The maximum mass attenuation coefficient (MAC) was recorded at a photon energy of 15 keV for the incorporation of lead. Half-value layer (HVL) values peaked at 6 MeV and it attained its maximum value for germanium. The highest and lowest values of the linear attenuation coefficients (LAC) were obtained for Se76Te20Sn2Pb2 and Se76Te20Sn2Ge2 alloys respectively. Notably, the Se76Te20Sn2Pb2 alloy exhibited the highest values of effective atomic number (Zeff), electron density (Neff), atomic cross-section (ACS), and electronic cross-section (ECS), indicating superior shielding performance. Conversely, energy absorption buildup factors (EABF) and exposure buildup factors (EBF) were highest for Se76Te20Sn2Ge2 alloy. Neutron attenuation was most effective in the Se76Te20Sn2In2 and Se76Te20Sn2Pb2 compositions. Overall, the incorporation of lead in the parent glass demonstrated superior shielding capability compared to the other compositions studied.

A Low‐Dimensional Donor‐Acceptor Perovskite for High‐Performance X‐Ray Detection

AbstractPerovskite materials hold significant promise for X‐ray detection due to their high X‐ray attenuation coefficient, efficient charge mobility, and tunable compositions and optoelectronic properties. Nonetheless, extracting the charges deep inside the thick semiconductors remains a challenge. Here, the 1D cytidine lead bromide perovskite (CytPbBr3) with a regularly arranged Donor (D)–Acceptor (A) heterojunction structure is reported. The organic interlayer contributes to the conduction band, while the inorganic framework constructs the valance band. Such a D–A heterojunction structure offers two separate channels for electrons and holes transport, suppressing the charge recombination rates with improved charge collection efficiency, and thus yields a high device sensitivity of 1.2 × 106 µC Gyair−1 cm−2 with a low noise equivalent dose (NED) of 44.6 pGyair.

A novel 3D polymer gel dosimeter based on polymethyl methacrylate gel (PMMAG) for radiotherapy: Ultrasonic evaluation

This study investigates the characteristics of a novel polymer gel dosimeter (PMMAG) for radiotherapy applications, focusing on its radiation absorption and sensitivity properties. The PMMAG dosimeters were evaluated using both UV–vis spectrophotometry and ultrasonic techniques. The results of the study, UV–vis analysis revealed a significant increase in dose response with the introduction of a cross-linker, peaking at a monomer-to-cross-linker ratio of 5:3. Sensitivity analysis indicated optimal sensitivity at this ratio, with values reaching 0.021 a.u./Gy. Ultrasound evaluation showed that the speed of sound and attenuation coefficient demonstrated a linear relationship and a strong positive correlation with an increase in the applied radiation dose, with the highest sensitivity observed at 8 Gy. The optimal sample exhibited the highest dose-response values at both 4 Gy and 8 Gy doses. Sensitivity values ranged from 2.1 to 2.75. The ultrasonic measurements demonstrated a significantly larger dynamic range in dose response curves compared to UV–vis dose-response data. It is concluded that ultrasound shows great potential as a technique for the evaluation of polymer gel dosimeters. The PMMAG can be introduced as a novel dosimeter for ionizing radiation dosimetry, validated through both optical and ultrasound assessment methods. The consistent and reliable performance of the PMMAG dosimeters makes them suitable for various applications in radiation therapy.

Influences of Variability in Attenuation Compensation on the Estimation of Backscatter Coefficient of Median Nerves in Vivo.

Peripheral nerves remain a challenging target for medical imaging, given their size, anatomical complexity, and structural heterogeneity. Quantitative ultrasound (QUS) applies a set of techniques to estimate tissue acoustic parameters independent of the imaging platform. Many useful medical and laboratory applications for QUS have been reported, but challenges remain for deployment in vivo, especially for heterogeneous tissues. Several phenomena introduce variability in attenuation estimates, which may influence the estimation of other QUS parameters. For example, estimating the backscatter coefficient (BSC) requires compensation for the attenuation of overlying tissues between the transducer and the underlying tissue of interest. The purpose of this study is to extend prior studies by investigating the efficacy of several analytical methods of estimating attenuation compensation on QUS outcomes in the human median nerve. Median nerves were imaged at the volar wrist in vivo and beam-formed radiofrequency (RF) data were acquired. Six analytical approaches for attenuation compensation were compared: 1-2) attenuation estimated by applying spectral difference method (SDM) and spectral log difference method (SLDM) independently to regions of interest (ROIs) overlying the nerve and to the nerve ROI itself; 3-4) attenuation estimation by applying SDM and SLDM to ROIs overlying the nerve, and transferring these properties to the nerve ROI; and 5-6) methods that apply previously published values of tissue attenuation to the measured thickness of each overlying tissue. Mean between-subject estimates of BSC-related outcomes as well as within-subject variability of these outcomes were compared among the 6 methods. Compensating for attenuation using SLDM and values from the literature reduced variability in BSC-based outcomes, compared to SDM. Variability in attenuation coefficients contributes substantially to variability in backscatter measurements. This work has implications for the application of QUS to in vivo diagnostic assessments in peripheral nerves and possibly other heterogeneous tissues.

Three-dimensional radiation dosimetry of carbon ion beams using surfactant hydrogels: Fundamental investigation.

In carbon ion radiotherapy, accurate measurement of the three-dimensional (3D) absorbed dose distribution is critical for effectively targeting tumors. Although micellar gel dosimeters exhibit considerable potential for measuring 3D absorbed dose distributions, few studies have focused on radiotherapy using carbon ion beams. This study investigated the applicability of the surfactant hydrogel dosimeter (SHD), a micellar gel dosimeter, to measuring a 3D dose absorbed through carbon ion beam irradiation. A cubic target region of 34mm per side was established at a depth of 46mm below the upper surface of an SHD specimen. Scanning irradiation was performed using a pencil beam of carbon ions at the Ion-beam Radiation Oncology Center in Kanagawa ("i-ROCK"), Japan, under irradiation conditions set by the treatment planning system ("Monaco for Carbon", Ver. 5.20, Elekta AB, Sweden) to create a spread-out Bragg peak within the target. The physical dose was set to 10Gy at the isocenter, situated at the center of the target. The SHD responsiveness was measured twice using optical computed tomography (CT) ("Vista 15", Modus Medical Devices, Canada) for three irradiated specimens, and six types of measured optical attenuation coefficient (OAC) were obtained. To assess whether the OAC represented the absorbed dose expected in the treatment plan, we compared the relative distribution of the OAC and that of the absorbed dose. Relative fraction (RF) was used to measure the difference between the relative value of the OAC and that of the absorbed dose. Moreover, the distribution of OH radical (•OH) concentration obtained by Monte Carlo simulation ("PHITS" ver. 3.24 JAEA, Japan) and that of the OAC were compared. In the direction of beam travel, the relative distribution of the OAC was lower than that of the absorbed dose. This discrepancy could be attributed to a decrease in the concentration of •OH produced by irradiation owing to the recombination reaction, which does not accurately reflect the absorbed dose. By contrast, the distributions in the plane perpendicular to the beam travel were consistent. The RF increased from±3% to±13% along the beam travel direction. The small RF in the plane perpendicular to the beam travel could be attributed to the constant distribution of linear energy transfer, regardless of the irradiation position, and the generation of radicals proportionally to the absorbed dose. The increase in RF along the beam travel direction was ascribed to ring artifacts in the irradiated region. The measurement of the absorbed dose distribution in the beam travel direction should be improved. The observed discrepancy is attributed to the reduced reactivity of the SHD due to a high liner energy transfer near the Bragg peak. However, the absorbed dose distribution can be effectively evaluated in the plane perpendicular to the direction of beam travel.

Attenuation coefficients of soy-lignin bonded Rhizophora spp. particleboard as a potential phantom material using Monte Carlo GATE

This work aimed to determine the linear and mass attenuation coefficients of soy-lignin bonded Rhizophora spp. particleboard intended for use as a phantom material using Monte Carlo GATE simulation. At a desired density of 1.0 gcm-3, particleboard constructed of Rhizophora spp. wood trunk bonded with soy flour and lignin was created. The sample’s elemental composition was identified using energy dispersive X-ray spectroscopy. The GATE software was used to simulate the setup with the histories of 1 × 107, and comparison was made between the experimental and simulation data. The disparities between the linear and mass attenuation coefficients of the samples experimentally measured and calculated using GATE at low energy photons were quite small. The result revealed a good agreement between the experimental and simulation data, and the attenuation coefficients were in close proximity with XCOM of water. The outcome revealed GATE adequacy for validation of attenuation coefficient measurement in bioresources phantom material for medical physics application.

Waveguide Acoustic Control of Pipes - Billets of Deep Rod Pumps

Deep rod pumps are expensive maintenance-free equipment for extracting oil from wells. The exclusion of defective billet pipes from the technological cycle of manufacturing elements of such pumps significantly affects both the cost of their production and the cost of production. A waveguide method is proposed for continuous input testing of tube billets of rod pump cylinders. It does not require scanning and is highly sensitive to both internal and surface defects. An experimental assessment of the sensitivity of the method to defects in the form of an influx located on the outer and inner surfaces of a thick-walled pipe with a diameter of 59.3 mm and a wall thickness of 14 mm was carried out. The echo signal from the artificial reflector decreased by 2 dB when the reflector was moved from the outside of the pipe to the inside. The criteria for rejection of the blank pipe are determined by the signal level at the first reflection R1, at the 8th reflection RN and by the attenuation coefficient b. As a result of flaw detection of billet pipes, a pipe with a significant defect was found. An experimental study of the acoustic properties of a batch of pipes with a diameter of 58 mm in the delivery state was carried out. For the billets of the cylinder of the deep rod pump in the delivery state, the lower acceptance limit for the torsional wave velocity of 3255 m/s has been determined. The influence of technological operations of high tempering and straightening on their acoustic properties is estimated. The possibility of quality control when performing the release operation by the guided wave method is shown. It was revealed that during the tempering procedure, the velocity of the torsional wave increases, on average, by 27 m/s per batch.

Exploring the Radiation Shielding Efficiency of High-Density Aluminosilicate Glasses and Low-Calcium SCMs

A lot of work is now going into making low-calcium supplementary cementitious materials (SCMs) and aluminosilicate glasses so that they can be used as radiation shielding materials. These materials demonstrate superior performance in several aspects as compared to conventional concrete. The present investigation focuses on the radiation shielding characteristics of the evaluated materials, specifically their capacity to reduce the intensity of gamma rays and neutrons. Regarded for their exceptional density and ability to include heavy metal oxides, aluminosilicate glasses have remarkable shielding characteristics, especially when designed at the molecular scale. An evaluation of the performance of these materials in comparison to traditional concrete is carried out using Phy-X/PSD software. The goal is to determine the most important shielding properties, such as the mass attenuation coefficient, the linear attenuation coefficient, and the half-value layer. Our study findings suggest that some aluminosilicate glasses, such as GM, consistently demonstrate exceptional photon and neutron attenuation efficiency. The observation that GM performs better than other materials in tests like effective atomic number, rapid neutron removal cross section, and energy absorption accumulation factor supports this claim. There is evidence that using low-calcium glass-crystal materials (SCMs) with aluminosilicate glasses not only improves radiation protection but also makes solutions work better when space or weight are limited. The present investigation validates that these materials exhibit superior performance compared to conventional concrete in challenging environments such as nuclear waste storage, where safety is of utmost significance.

Measurement of average mass attenuation coefficient of air for 137Cs gamma-ray irradiation beam

Abstract The average mass attenuation coefficient of air for the KRISS 137Cs gamma-ray irradiation beam was measured using a 30 cm-long vacuum-sealable cylindrical column. Six different models of ionization chambers were employed for the measurement. Under ambient room conditions, the average mass attenuation coefficient was found to be (0.0778 ± 0.0012) cm2 g−1 across the six chambers. This coefficient will be used to adjust the variation in air kerma with air density for the 137Cs gamma-ray irradiation beam.

Effect of Sm2O3 on thermal, optical, mechanical, gamma and neutron shielding properties of zinc-boro-vanadate glasses

Abstract The effect of Sm2O3 on thermal, optical, mechanical, gamma and neutron shielding properties of newly prepared zinc borovanadate glasses has been investigated. Density is found increased and molar volume decreased with Sm2O3 content. The glass transition temperature ( T g ) , crystallization temperature ( T c ) and the peak crystallization temperature ( T P ) increased with increase of rare earth oxide content. These findings demonstrated an excellent glass-forming ability and thermal stability of the glasses. The optical properties have been explored through UV–vis spectroscopy. The indirect optical band gap energy ( E opt ) decreased from 2.978 to 2.679 eV, Urbach energy ( ∆ E ) increased from 0.273 to 0.299 eV and refractive index increased from 2.403 to 2.489 with increase in Sm2O3. Elastic moduli, Poisson’s ratio, Hardness and fractal bond connectivity were computed theoretically as per Makishima Mackenzie model. It is found that these glasses have appreciable mechanical strength and rigidity. Phy-X/PSD software has been used to determine different radiation shielding characteristics for the energy range 0.015–15 MeV. The mass and linear attenuation coefficients are found higher, and half value layer, tenth value layer and mean free paths are found lower than many radiation shielding glasses quoted in the literature values. The obtained Z eq values varied from 15.828–29.118 for energy range from 0.015 to 15 MeV, which are greater than those reported for several commercial glasses, concretes and rocks. Due to the Compton scattering process, exposure build up and energy absorption factor are found to be highest in the medium energy region. The fast neutron removal cross-sections of the glasses are observed to be significantly high. For the first time, thermally stable and mechanically strong zinc borovanadate glasses mixed with Sm2O3 have been thoroughly investigated for various properties and concluded that these glasses are suitable for optoelectronics and γ-shielding applications.

Estimating Vertical Distribution of Total Suspended Matter in Coastal Waters Using Remote-Sensing Approaches

The vertical distribution of the marine total suspended matter (TSM) concentration significantly influences marine material transport, sedimentation processes, and biogeochemical cycles. Traditional field observations are constrained by limited spatial and temporal coverage, necessitating the use of remote-sensing technology to comprehensively understand TSM variations over extensive areas and periods. This study proposes a remote-sensing approach to estimate the vertical distribution of TSM concentrations using MODIS satellite data, with the Bohai Sea and Yellow Sea (BSYS) as a case study. Extensive field measurements across various hydrological conditions and seasons enabled accurate reconstruction of in situ TSM vertical distributions from bio-optical parameters, including the attenuation coefficient, particle backscattering coefficient, particle size, and number concentration, achieving a determination coefficient of 0.90 and a mean absolute percentage error of 26.5%. In situ measurements revealed two distinct TSM vertical profile types (vertically uniform and increasing) and significant variation in TSM profiles in the BSYS. Using surface TSM concentrations, wind speed, and water depth, we developed and validated a remote-sensing approach to classify TSM vertical profile types, achieving an accuracy of 84.3%. Combining this classification with a layer-to-layer regression model, we successfully estimated TSM vertical profiles from MODIS observation. Long-term MODIS product analysis revealed significant spatiotemporal variations in TSM vertical distributions and column-integrated TSM concentrations, particularly in nearshore regions. These findings provide valuable insights for studying marine sedimentation and biological processes and offer a reference for the remote-sensing estimation of the TSM vertical distribution in other marine regions.

Scaling Law of Flow and Heat Transfer Characteristics in Turbulent Radiative Rayleigh-Bénard Convection of Optically Thick Media

Radiative natural convection is of vital importance in the process of energy storage, power generation, and thermal storage technology. As the attenuation coefficients of many heat transfer media in these fields are high enough to be considered as optically thick media, like nanofluids or molten salts in concentrated solar power or phase change thermal storage, Rosseland approximation is commonly used. In this paper, we delve into the impact of thermal radiation on the Rayleigh-Bénard (RB) convection. Theoretical analysis has been conducted by modifying the Grossmann-Lohse (GL) model. Based on turbulent dissipation theory, the corresponding scaling laws in four main regimes are proposed. Direct numerical simulation (DNS) was also performed, revealing that radiation exerts a notable influence on both flow and heat transfer, particularly on the formation of large-scale circulation. By comparing with DNS results, it is found that due to the presence of radiation, the modified Nu scaling law in small Pr range of the GL model is more suitable for predicting the transport characteristics of optical thick media with large Pr. The maximum deviation between the results of DNS and prediction model is about 10%, suggesting the summarized scaling law can effectively predict the Nu of radiative RB convection.

Investigation of thermal, acoustic, mechanical, and radiation shielding performance of waste and natural fibers

It is crucial to address two pressing global issues, energy shortage and environmental pollution, when producing building insulation materials. Using waste and natural fiber groups can be part of the solution. The insulation material was produced using pumpkin fiber, chicken fiber, cotton waste, vermiculite, and epoxy as binders. The samples were tested for thermal conductivity coefficient, ultrasonic sound transmission rate, density, water absorption rate, compressive and bending strength, and fire resistance at temperatures of 75, 100, 125, and 150C. The samples produced using natural and waste materials yielded a thermal conductivity value of 0.041 W/mK, an ultrasonic sound transmission speed of 0.25 km/s, a compressive strength value of 1.57 MPa, and bending strength values of 0.91 MPa. It has been clearly demonstrated that, with its low volume loss, it can serve as an alternative to the EPS-XPS types available in the market. Furthermore, the linear attenuation coefficients (LAC) were examined to obtain radiation shielding properties of the samples at 1173 and 133 keV energies using a 60Co gamma source. Also, LAC values determined between 0,1167 ± 0,0452 cm−1-0,2315 ± 0,0065 cm−1 for 1173 keV and 0,1042 ± 0,0488 cm−1 - 0,2141 ± 0,0062 cm−1 for 1333 keV. Accordingly, it has been revealed that waste compositions are effective in protecting against radiation.

Aloebarbadensis - Assisted MgBiO/MgCuBiO/MgBaBiO nanocomposites as effective gamma shielding novel materials

For the first of its kind, MgO/Bi2O3 (1:1) (MBO), MgO/CuO/Bi2O3 (1:1:1) (MCBO) and MgO/BaO/Bi2O3 (1:1:1) (MBBO) binary/ternary nanocomposites (NCs) were synthesized by Aloe barbadensis (Aloe vera) mediated solution combustion method. The as-formed NCs are subjected to calcination for 3 h at 600oC.The Mg-based NCs acquired are subjected to various analytical characterization methodologies, including PXRD (Powder X-ray Diffraction), SEM (Scanning Electron Microscopy), EDS (Energy Dispersive X-ray Spectroscopy), FTIR (Fourier Transform Infrared Spectroscopy), and Ultraviolet–Visible Spectroscopy (UV–Vis). The Bragg reflections confirm the formation of monoclinic phase BaO, Bi2O3, cubic MgO and tetragonal CuO nanoparticles. The surface morphology of MBO, MCBO and MBBO NCs consists of irregular sized, leafy and burrow like structured agglomerated NPs with hollows and voids/pores. The Eg (direct energy band gap) determined from W-H (Wood and Tauc's) plot was found to be 3.09, 3.19 and 3.12 eV for MBO, MCBO and MBBO NCs respectively. The evaluation of gamma radiation shielding properties was conducted using a NaI (Tl) detector connected to a multi-channel analyzer. Shielding parameters of MBO, MCBO and MBBO, such as μ/ρ (mass attenuation coefficient), λ (mean free path), HVL (half-value layer), TVL (tenth-value layer) are measured. Among the as-synthesized Mg-based NCs, MBO exhibits better shielding properties compared to MCBO and MBBO. Thus, the procured Mg-based NCs are suitable for applications where weight reduction is critical, such as aerospace or portable radiation shielding systems.