Attenuation Coefficient Values Research Articles

Head-to-head comparison of three different US-based quantitative parameters for hepatic steatosis assessment: a prospective study.

To evaluate the diagnostic performance of attenuation coefficient (AC), hepato-renal index (HRI) and controlled attenuation parameter (CAP) in quantitative assessment of hepatic steatosis by employing histopathology as reference standard. Participants with suspected metabolic-associated fatty liver disease(MAFLD) who underwent US-based parameter examinations and liver biopsy were prospectively recruited. The distributions of US parameters across different grades of steatosis were calculated, and diagnostic performance was determined based on the areas under the receiver operating characteristic curve (AUC). A total of 73 participants were included, with hepatic steatosis grades S0, S1, S2, and S3 distributed as follows: 13, 20, 27, and 13 respectively. The correlation coefficients for CAP, AC, and HRI ranged from 0.67 to 0.74. AC and HRI showed a strong correlation with steatosis grade. The AUC for CAP and AC in diagnosing steatosis ≥ S1 were significantly higher at 0.99 and 0.98 compared to HRI's value. For diagnosing steatosis ≥ S2, the AUC of CAP (AUC: 0.85) was lower than that of AC (AUC: 0.94), and HRI (AUC: 0.94). Similarly for diagnosing steatosis S3, the AUC of CAP (AUC: 0.68) was lower than that of AC (AUC: 0.88), and HRI (AUC: 0.88). The AC and HRI values increased with the progression of hepatic steatosis grade, while CAP increased from S0 to S2 but not from S2 to S3. For mild steatosis diagnosis, CAP and AC showed superior diagnostic performance compared to HRI, while AC and HRI were more advantageous in differentiating moderate and severe steatosis.

Utilization of Waste Marble and Bi2O3-NPs as a Sustainable Replacement for Lead Materials for Radiation Shielding Applications

In an attempt to reutilize marble waste, a new approach is presented in the current study to promote its use in the field of shielding against ionizing radiation. In this study, we aimed to develop a novel and sustainable/eco-friendly lead-free radiation shielding material by improving artificial marble (AM) produced from marble waste combined with polyester by reinforcing it with bismuth oxide (Bi2O3) nanoparticles. Six samples of AM samples doped with different concentrations (0%, 5%, 10%, 15%, 20%, and 25%) of Bi2O3 nanoparticles were prepared. The linear attenuation coefficient (LAC) values were measured experimentally through the narrow beam method at different energies (0.0595 MeV, 0.6617 MeV, 1.1730 MeV, and 1.330 MeV) for all samples with various concentrations of Bi2O3. Radiological shielding parameters such as half value layer (HVL), tenth-value layer (TVL), and radiation shielding efficiency (RSE) were estimated and compared for all the different samples. The results prove that increasing the concentration of Bi2O3 leads to the enhancement of the radiation shielding properties of the AM as a shielding material. It was observed that as the energy increases, the efficiency of the samples falls. High energy dependence was found when calculating the HVL and TVL values of the samples, which increased with increases in the energy of the incident photons. A comparison between the sample with the most efficient gamma radiation attenuation capability (AM-25%), concrete, and lead was conducted, and a discussion regarding their radiation shielding properties is presented herein. The results show that the AM-25% sample is superior to the ordinary concrete over all the studied energy ranges, as evidenced by its significantly lower HVLs. On the contrary, lead is superior to the AM-25% sample over all the studied energy ranges owing to its unbeatable density as a shielding material. Overall, this new type of artificial marble has the potential to be used as a radiation shielding material at low- to medium-gamma energy regions, specifically in medical imaging and radiation therapy.

Impact of Bi2O3 on the glass system B2O3 -TeO2–MgO–PbO on the purpose of radiation shielding efficacy

In this study, eight glass samples were prepared with the composition of [x Bi2O3-(75-x) B2O3–15TeO2 –5MgO–5PbO; where x = 0, 10, 20, 25, 30, 40, 50, and 60 mol%]. In the composition of those glass samples, various amountsof B2O3 were replaced by Bi2O3 to improve the glass material's radiation shielding capability. The mechanical properties of these glasses have been evaluated using densimeter and microhardness. The Vickers microhardness (Hv) slightly decreases as the amount of Bi2O3 increases due to the formation of Non-Bridging Oxygen (NBO). To evaluate the radiation shielding effectiveness of the prepared glass samples, we performed Monte Carlo simulations of several shielding parameters. The mass attenuation coefficients of the experimentally produced BTMPBi glass series were calculated using NIST and MCNP6, and reasonable agreement was found between the simulation and experimental results. The relative difference between NIST and MCNP6-based results was calculated, and the maximum deviation was 2.21% for the 1173 keV gamma ray incident in the BTMPBi60 glass sample. The value of the mean free path of those prepared glass samples maintained the following trend - BTMPBi0> BTMPBi10> BTMPBi20> BTMPBi25> BTMPBi30> BTMPBi40> BTMPBi50>BTMPBi60. The prepared glass sample BTMPBi0 showed a 2.6 times higher value of the mean free path at energy 1332 KeV compared with the prepared BTMPBi60. Analyzing the composition of the prepared glass samples, it is clear that the greater the amount of Bi2O3 the greater the value of linear attenuation coefficient (LAC) and effective atomic number. Based on the results, it can be concluded that the glass sample containing 60 mol % of Bi2O3 (BTMPBi60) exhibited the highest radiation shielding capability among all of the prepared samples.

Improved Radiation Shielding Efficiency and Optical Properties of Borate Glass by Incorporating Dysprosium(III) Oxide

The present investigation used the melt-quench method to produce four distinct glass systems using boron-Dy2O3 glass. The glass system consisting of B2O3, BaO, ZnO, and Li2O was augmented with Dysprosium(III) Oxide. A series of borate glasses with the chemical formula (62-x)B2O3-18BaO-10ZnO-10Li2O-xDy2O3 where x=0, 1, 2, 3mol%. The experimental investigation of Dy2O3 as additives was conducted, with a specific emphasis on their optical characteristics. Also, the addition of Dy2O3 causes the intensity of absorption to increase. Moreover, because of changes in the glass network and modifier, the absorption edge moved to a higher wavelength as the concentration of Dy3+ ions increased, from 345.46nm for Dy–0 to 367.48nm for Dy–3. This study examined glasses with different compositions to evaluate their effectiveness in shielding γ-rays. The Phy-X/PDS and FULKA Code were utilised for this investigation. A comparison analysis was performed on the obtained results. The effective atomic number and other parameters, such as linear attenuation coefficient and half value layer, were calculated within the energy range of 0.015 to 15MeV. The study revealed that the Dy-0 has the lowest linear attenuation coefficient compared to the other samples analysed. The glasses Dy-0 and Dy-3 showed half-values of 0.044 and 0.039cm, respectively, when exposed to 0.05MeV. The increase in effective atomic number was attributed to a higher quantity of electrons that are accessible for photon interaction. This, in turn, resulted in a reduced probability of γ-ray passage through the shielding material. According to the findings of the gamma radiation shielding experiment, the sample that had the largest amount of Dy2O3 exhibited the most effective shielding qualities, making it an excellent candidate for use in radiation shielding applications.

The Effects of phase interfaces in SmFeN/YSZ composite thermal Barrier Materials on Electromagnetic Wave-absorbing properties

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 (C0), impedance matching, and minimum reflection loss (RLmin) 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 RLmin = -27.824 dB and effective absorption bandwidth (EAB) = 8.5453GHz (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.

Preparation and structure investigation of polyethylene terephthalate polyester reinforced Ni0.5Zn0.5Fe2O4 nanoparticles for gamma ray shielding performance

Defects of high atomic materials gamma-ray shielding such as low chemical stability, low mechanical properties, and heaviness lead us to investigate other light and flexible materials such as polymers. Polymer-doped nanosized materials are the most frequently examined materials. In this study, polyethylene terephthalate [(C10H8O4)n] was doped with Ni0.5Zn0.5Fe2O4 nanoparticles up to 40 wt% (0.0, 10.0, 20.0, 40.0 wt%) prepared by Sol–Gel auto-combustion method with the help of Gelatin. The polyester/Nanofiller composite structures were identified using x-ray photoelectron spectroscopy, x-ray diffraction, Scanning, and Transmission electron microscope as well as density measurements. x-ray photoelectron spectroscopy confirmed the successful doping of nanofiller in the polyester structure as Zn signals appear in the atomic composition and Fe signals appear in the deconvolution of the peaks. x-ray diffraction, transmission, and scanning electron microscope display the same result. x-ray diffraction graph information with the Scherer equation offered the crystal size of the composite (26 nm). Polyester/nanofiller samples were scanned against gamma-ray and experimental shielding factors were computed using a narrow beam transmission technique with sodium iodide detector and two-point sources Cs-137 and Co-60. Experimental Linear and mass attenuation coefficient values swelled as percentages of nanofiller increased in the polyester structure. Experimental Mass attenuation values were compared with theoretical ones estimated from XCOM and Physics-X programs. The difference between them does not exceed 12% which is acceptable as the x-ray photoelectron spectroscopy atomic composition utilized in the theoretical data calculation does not reveal Ni signals. This may occur at the depth of the composite structure. Finally, the half-value layer, the Tenth value layer, and the Mean free path are determined experimentally, and their values are reduced as the nanofiller doping percentage rises in the structure. This result confirms the efficiency of nanofiller addition to the polyester structure to attenuate gamma-ray.

Does Meal or Water Intake Affect Ultrasound Attenuation Coefficient Estimate?

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. 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. 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. 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.

Experimental radiation shielding, mechanical and optical properties for borosilicate glass system: Role of varying SrO

Borosilicate glass is one of the famous glasses used in labs and kitchenware since its thermal expansion is so low. This research synthesized a new group of borosilicate glass to study its mechanical, optical, and radiation shielding properties. The experimental shielding setup was set to explore the glass performance in the radiation shielding field. The results were compared with the XCOM data to check validity. The optical properties were determined using absorption spectra for glass samples. At the same time, the mechanical properties were assessed theoretically to give an impression of the glass structure. The radiation shielding experimental setup was validated with a relative difference of 9.8066% between practical and theoretical findings. Meanwhile, adding SrO instead of B2O3 increased the radiation shielding features. The mass attenuation coefficient values at 0.184 MeV rose from 0.1448 to 0.1474 cm2/g with the addition of SrO. The mechanical and optical parameters showed variation in results when SrO was added. For example, the band gap values are 3.547, 3.485, 3.675, and 3.527 eV for STBS15, STBS20, STBS25, and STBS30, respectively. The Urbach energy results are 0.183, 0.182, 0.180, and 0.173 eV for STBS15, STBS20, STBS25, and STBS30, respectively. At the same time, the Young modulus results are 94.071, 88.880, 89.207, and 86.035 GPa for STBS15, STBS20, STBS25, and STBS30, respectively. The Poisson ratio ranged from 0.284 to 0.278 for STBS15 and STBS30. The adding SrO reduced the hardness from 5.260 to 4.966 GPa for STBS15 and STBS30. Finally, the results indicate the ability to use current glasses in the radiation shielding applications.

Simultaneous use of bismuth trioxide and mill scale for ternary blended geopolymer composite in radiation shielding applications

The present study evaluates Mill scale which is a steel industry waste and bismuth trioxide simultaneously as a potential radiation shielding material in geopolymer composite. An innovative and first of its kind lead-free design has been developed for making radiation shielding materials using mill scale and bismuth trioxide as shielding aggregates and industrial wastes such as fly ash and blast furnace slag as precursors for the geopolymer composite. The mill scale and bismuth trioxide based composite material are characterized for their radiation shielding characteristics based on shielding parameters commonly used in radiation shielding like linear attenuation coefficient (μ), half value thickness (HVT) and Mean Free Path (MVP) for 0.662 MeV energy. The determined shielding parameters are compared with traditional shielding materials like concrete with heavy aggregates. X-Ray diffraction studies have confirmed the presence of Bismuth ferrite as the major shielding phase responsible for radiation shielding. The mechanical properties of the prepared composites are determined for their strength in direct compression. Depending upon the radiation shielding parameters like linear attenuation coefficient and half value thickness an optimum dosage of mill scale and bismuth trioxide as a shielding composite to provide adequate shielding for X-Ray diagnostic and medical facilities against X-ray photons of low intensity has been recommended. The highest linear attenuation coefficient values of fly ash and slag based geopolymer composites had been observed to be 0.208 and 0.225, respectively.

Titanium alloys: A closer-look at mechanical, gamma-ray, neutron, and transmission properties of different grade alloys through MCNPcode application

Titanium alloys play a vital role in optimizing the effectiveness and security of nuclear reactors, strengthening structural durability, and facilitating the effective handling of nuclear waste. The aim of this study is to investigate the gamma-ray, neutron, and transmission properties of four common titanium alloys through the examination of the deposited energy amount in the liquid sodium coolant material, in relation to the mechanical properties of these alloys. MCNP (version 6.3) is utilized for designing the titanium pipes. Next, the pipes were re-designed considering the elemental mass fractions and densities of the investigated titanium alloys. Grade 26 sample is reported with the highest values of mass attenuation coefficients and the lowest HVL values among those investigated alloys. Grade 26 is reported to have the lowest TF value, whereas Grade 12 demonstrated the highest TF value. The highest Effective Removal Cross Section (ΣR, 1/cm) value against fast neutrons is reported for Grade 26. The utilization of Grade 26 sample as pipe material resulted in the lowest deposited energy amount (MeV/g) and subsequent lowest contamination in the coolant material. Out of the alloys that were chosen for analysis, it has been determined that Grade 26 exhibits the highest level of strength. It can be concluded that the Grade 26 alloy exhibits desirable characteristics for applications in nuclear technologies that require superior gamma-ray and neutron absorption properties, as well as exceptional mechanical properties. Nevertheless, it is essential to emphasize the importance for ongoing studies to enhance the existing material properties of Grade 26, with the aim of achieving improved safety and efficacy in nuclear applications.

Extensive analysis of several Indian and Yemeni soils' gamma-ray shielding characteristics: An experimental and simulation approach

The linear attenuation coefficients (LAC) of four soils (Black cotton (S1), Sandy (S2), Clay (S3), and Sandy (S4)) samples were measured at photon energies released from radioisotopes Co57 (122 keV), Ba133 (356 keV), 22Na (511 and 1275 keV), Cs137 (662 keV), Mn54 (840 keV), and Co60 (1330 keV) using a gamma spectrometer includes a NaI (Tl) scintillation detector. The experimental measurements were confirmed utilizing the Monte Carlo N-particle transport code. The linear attenuation coefficient values enhanced from 0.256 cm−1 to 0.296 cm−1 (at Eγ of 122 keV), from 0.126 cm−1 to 0.142 cm−1 (at Eγ of 662 keV), and from 0.0938 cm−1 to 0.105 cm−1 (at Eγ of 1275 keV), raising the (Fe + Mn) concentration from 0.912 wt% to 11.214 wt%, as well as raising the soil samples density from 1.62 g/cm3 to 1.79 g/cm3. The study also shows an enhancement in the half value thickness, transmission factor, radiation protection efficiency and lead's equivalent thickness due to the enrichment of Fe + Mn concentrations within the studied soils. The results show that the Black cotton soil exhibits better shielding properties for γ-ray than the other soils.

Performance of ATT and UDFF in the diagnosis of non-alcoholic fatty liver: An animal experiment

ObjectiveTo establish a Bama minipigs model with Non-Alcoholic Fatty Liver (NAFL) induced by a high-fat diet and investigate the application of attenuation coefficient (ATT) and ultrasound-derived fat fraction (UDFF) in the diagnosis of NAFL. MethodsSix-month-old male Bama minipigs were randomly divided into normal control and high-fat groups (n = 3 pigs per group), and fed with a control diet and high-fat diet for 32 weeks. Weight and body length were measured every four weeks, followed by quantitative ultrasound imaging (ATT and UDFF), blood biochemical markers, and liver biopsies on the same day. Using the Non-Alcoholic Fatty Liver Disease (NAFLD) Activity Score (NAS) as a reference, we analyzed the correlation between ATT, UDFF, and their score results. ResultsCompared with the normal control group, the body weight, body mass index (BMI), and serum levels of triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in the High-fat group were significantly different at Week 12 (P < 0.05). Spearman correlation analysis showed that the ATT value was significantly correlated with NAS score (r = 0.76, P < 0.001), and the UDFF value was significantly correlated with NAS score (r = 0.80, P < 0.001). The optimal cut-off value of ATT and UDFF were 0.59 dB/cm/MHz and 5.5%, respectively. These values are optimal for diagnosis of NAFL in Bama minipig model. ConclusionATT and UDFF have a high correlation with steatosis, and can be used as a non-invasive method for early screening of hepatic steatosis, which can dynamically monitor the change of disease course.

Gamma radiation shielding efficiency of some different ceramic composites: A comparative study

The development of a non-toxic, and low-cost material that offers good shielding against harmful ionizing radiation is highly demanded. This work offers a strategy for combining ceramic composites and carbon nanotubes to produce composites with desirable radiation shielding properties. First, we successfully prepared barium titanate (BT) ceramic by sol-gel auto-combustion method. Then, a series of CERAM-1, CERAM-2, and CERAM-3 ceramic composites were formed by inserting into BT different types of ferrite and carbon nanotubes. The crystal structural analysis indicated that all ceramic composites crystallized into a cubic structure. The crystallite sizes of the final products were calculated and were found to be 30.8 nm, 25.4 nm, 35.9 nm, and 33.1 nm for pure BT, CERAM-1, CERAM-2, and CERAM-3, respectively. The gamma radiation shielding parameters were experimentally examined at four energies ranging from low to high energy radiation. At 0.06 MeV, the ceramics have the greatest linear attenuation coefficient (LAC) values, ranging from 31.760 to 29.683 cm−1. The results showed that CERAM-1 has the greatest LAC values at 0.060 and 0.662 MeV, which indicated that CERAM-1 is the most effective shield to its advantage over the other ceramic samples at low and middle energies. Based on the obtained results, it can be concluded that various prepared ceramics can be useful for low-energy radiation protective applications.

Gamma and neutron attenuation of Bi2O3/CaO modified borovanadate glasses for radiation shielding applications

This article investigates the attenuation features of gamma and neutron radiations for Bi2O3/CaO modified borovanadate glasses. We assess the attenuation coefficients, half value layer (HVL), and mean free path (MFP) of a glass system under different radiation sources and energies. By using PHITS simulation platform, this investigation involves examining different configurations of the studied glass system, including variations in composition and thickness, to optimize its effectiveness as a shielding material. The simulation findings offer valuable insights into the radiation shielding properties of the glass system involved. The obtained results reveal that there is a significant impact for adding Bi2O3 to enhance the values of attenuation coefficients and then improve the shielding performance of the glassy system involved. For example, LAC values at 15 keV are 59.15, 151.89, and 230.05 cm−1, for VBC-Bi20, VBC-Bi20, and VBC-Bi20, respectively. Moreover, the MAC values of VBC-Bi20 specimen are higher than those different commercial glasses such as RS 253, RS 253 G18, and RS 323 G19. These insights assist in the design and development of efficient radiation shielding materials for practical applications in industries like nuclear and medical fields.

The Diagnostic Value of Ultrasound-guided Attenuation Parameter (UGAP) in metabolic fatty liver disease

Objectives:: To evaluate the diagnostic value of ultrasound-guided attenuation parameter (UGAP) in metabolic fatty liver disease (MAFLD) and to explore the correlation between the attenuation coefficient (AC) value of UGAP and commonly used clinical obesity indicators. Methods:: A total of 121 subjects who had physical examinations from November 2021 to March 2022 were prospectively selected; the height, weight, and waist circumference (WC) of all subjects were collected, and conventional ultrasound and UGAP examinations for all subjects Results:: Under the standard of conventional ultrasound, among the 121 subjects, 53 had normal liver, 42 had mild fatty liver, 21 had moderate fatty liver, and 5 had severe fatty liver. The mean AC value of 121 patients was 0.66 0.13 dB/cm/MHz. The best cut-off values for diagnosing mild, moderate, and severe fatty liver were 0.65dB/cm/MHz, 0.72dB/cm/MHz, and 0.83dB/cm/MHz, respectively. The area under the curve (AUC) values were 0.891, 0.929, and 0.914, respectively. When grouped by WC, there was a statistically significant difference in AC value between the normal group and the obese group (t=-4.675, P&lt;0.001). Overall WC and within group WC were moderately correlated with the AC value of UGAP (P&lt;0.001). Conclusions:: UGAP has a good diagnostic value in the quantitative evaluation of liver steatosis in MAFLD, and the change of WC can reflect the occurrence of liver steatosis to a certain extent.

Red-Mud, A Golden Waste for Radiation Shielding”: Red-Mud Polymer Composites for High-Performance Radiation-Shielding Components

Red mud (RM) is generated in huge quantities and holds the ability to form radiation shielding structures due to its metal oxide-rich composition. In this work, this metal oxide-rich waste is converted into X-ray shielding sheets via a solution-casting technique incorporating polyvinyl alcohol (PVA) as a binder which holds RM particles together. We show a successful fabrication of sheets employing varying wt.% of RM (60, 70, 80, and 90 wt.%). The linear attenuation coefficient (LAC) values have been compared to analyze what maximum RM wt.% can effectively shield diagnostic X-rays at energies of 60 kVp, 90 kVp, and 120 kVp. Structural characterizations of the fabricated samples have been examined through SEM, XRD, RAMAN, and FTIR. The LAC analysis revealed that 70 wt.% of RM with PVA binder yields highest radiation shielding. However, with increased wt.% of RM there is a catastrophic decrease in strength and shielding capability of the composite due to the formation of voids due to decreased wt.% of polymer binder. So, an innovative polymer-rich coating has been applied to RM composite having 90 wt.% of RM, which boosted the LAC and strength, but not more than RM composite having 70 or 80 wt.% of RM. The UV shielding analysis of best samples having 70 and 80 wt.% of RM was also analyzed to show the capability of RM in shielding UV along with X-ray.

Study Attenuation Parameters and Physical Properties of Silicone Rubber Reinforced with Nano- and Micro-Sized Aluminum Oxide Composites

Theoretical and practical research has been done on reinforced polymer composites, a more recent type of improved shielding material. This study examined the protective qualities of silicone rubber packed with nano- and micro-sized Al2O3. Aspects like the effective atomic number, mean free path, linear attenuation coefficient, and mass attenuation coefficient are used to evaluate these shielding materials. In terms of weight percentage and size, Al2O3 particles have been used to reinforce silicone rubber. Energy dispersive X-ray spectroscopy, X-ray diffraction, UV visible spectrometer, thermal analysis, and Fourier transform infrared spectroscopy have been investigated. The results show that aluminum oxide nanoparticles have a more homogeneous distribution within the samples than micro aluminum oxide particles, which is due to the fact that nanoparticles have a very large surface area-to-volume ratio when compared to the same material in bulk. As a result, the sample containing 40% by weight of nano Al2O3 has the largest attenuation coefficient value and the lowest half value layer (HVL), tenth value layer (TVL), and mean free path (MFP) values. Finally, it can be concluded that the sample containing nano Al2O3 can be utilized to create an innovative and versatile silicone rubber material. This material holds great potential for the manufacturing of gloves and protective jackets, specifically designed for radiation and nuclear shielding applications.

Synthesis and characterizations of Ce-doped ZnO thin films for radiation shielding

In this research, different amounts of Ce-doped ZnO thin films were synthesized using the spray pyrolysis method. Structural, morphological and optical properties of these synthesized films were investigated. In XRD analyses, wurtzite (hexagonal) structures were observed in the films. In SEM analysis, there were changes in the surface morphology of the films with doping, and in cross-section measurement, the thickness of the films was measured to be approximately 1.2 μm. In UV–vis spectrometry analysis, it is seen that the effect of Cerium contribution on optical transmittance and band gap positively affects shielding. NaI(Tl) detector and gamma energies of 384, 1173, and 1333 keV have been used to investigate the radiation protection properties of these synthesized films. As a result of these measurements, linear attenuation coefficient (LAC) values have been obtained. Radiation shielding parameters have been calculated with these (LAC) values. The Mass Attenuation Coefficient (MAC), Half Value Layer (HVL), Tenth Value Layer TVL (and) Mean Free Path (MFP) values have been also calculated using this LAC result. According to these results, Ce-doped ZnO films were found to be effective in radiation shielding.

Detection of acute and early-delayed radiation-induced changes in the white matter of the rat brain based on numerical processing of optical coherence tomography data.

Detection of radiation-induced changes of the brain white matter is important for brain neoplasms repeated surgery. We investigated the influence of irradiation on the scattering properties of the white matter using optical coherence tomography (OCT). Healthy Wistar rats undergone the irradiation of the brain right hemisphere. At seven time points from the irradiation procedure (2-14 weeks), an ex vivo OCT study was performed with subsequent calculation of attenuation coefficient values in the corpus callosum followed by immunohistochemical analysis. As a result, we discovered acute and early-delayed changes characterized by the edema of different severity, accompanied by a statistically significant decrease in attenuation coefficient values. In particular, these changes were found at 2 weeks after irradiation in the irradiated hemisphere, while at 6- and 12-week time points they affected both irradiated and contralateral hemisphere. Thus, radiation-induced changes occurring in white matter during the first 3 months after irradiation can be detected by OCT.

Comparative study between micro- and nano-carbon with epoxy for gamma shielding applications

In the current study, the epoxy material was mixed with 10%, and 30% weight percent carbon material as filler in different thicknesses (1 cm, 1.5 cm, and 2 cm). Transmission electron microscope (TEM) measurements showed the average size of the nano-carbon was 20 nm with a standard deviation of 5 nm. The morphology of samples was examined using scanning electron microscopy (SEM), which showed the flatness of the epoxy surface, and when the content of carbon increases, the connection between the epoxy array and carbon increases. The compression test indicates the effect of nano-size on enhancing the mechanical properties of the studied samples. To survey the shielding properties of the epoxy/carbon composites using gamma-rays emitted from Am-241, Ba-133, Cs-137, Co-60, and Eu-152 sources, which covered a wide range of energies from 0.059 up to 1.408 MeV, the gamma intensity was measured using the NaI (Tl) detector. The linear and mass attenuation coefficients were calculated by obtaining the area under each peak of the energy spectrum observed from Genie 2000 software in the presence and absence of the sample. The experimental results obtained were compared theoretically with XCOM software. The comparison examined the validity of experimental results where the relative division rate ranged between 0.02 and 2%. Also, the measurement of the relative division rate between linear attenuation coefficients of micro- and nano-composites was found to range from 0.9 to 21% The other shielding parameters are calculated at the same range of energy, such as a half-value layer (HVL), mean free path (MFP), tenth-value layer (TVL), effective atomic number (Zeff), and the buildup factors (EBF and EABF). The data revealed a consistent reduction in the particle size of the shielding material across various weight percentages, resulting in enhanced radiation shielding capabilities. The sample that contains 30% nano-carbon has the lowest values of TVL (29.4 cm) and HVL (8.85 cm); moreover, it has the highest value of the linear attenuation coefficient (LAC), which makes it the best in its ability to attenuate radiation.