76 research outputs found

    Fabrication and characterization of clay-polyethylene composite opted for shielding of ionizing radiation

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    This study fabricated and characterized a self-sustaining hydrogenous content claypolyethylene composite opted for ionizing radiation shielding. Composites designated A–G were fabricated each containing 0–30 wt% of recycled low density polyethylene (LDPE), respectively. To know the effects of the incorporated LDPE on the morphology, microstructural, compressive strength, thermal property and displacement effect on the vital elements were studied using scanning electron microscopy (SEM), X-ray diffractometry (XRD), universal mechanical testing machine, differential thermal analysis (DTA), Rutherford backscattering (RBS) technique and particle induced X-ray emission (PIXE), respectively. The bulk densities of the clay composites ranged between 1.341 and 2.030 g/cm3. The samples’ XRD analysis revealed similar patterns, with a sharp and prominent peak at angle 2 equals ~26.11 , which matched with card number 16-0606 of the Joint Committee on Powder Diffraction Standards (JCPDS) that represents Aluminum Silicate Hydroxide (Al2Si2O5(OH)4), a basic formula for Kaolin clay. The compressive strength ranged between 2.52 and 5.53 MPa. The ratio of Si to Al in each composite is about 1:1. The dehydroxylation temperature for samples ranged between 443.23 C and 555.23 C.http://www.mdpi.com/journal/crystalsam2022Physic

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Investigations of gamma ray and fast neutron shielding properties of tellurite glasses with different oxide compositions

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    In the present paper, the basic radiation parameters of tellurite glasses with different forming oxides (B2O3, BaO, K2O, V2O5, WO3 and ZnO) have been studied over a wide photon energy range from 1 keV to 100 GeV, using WinXCom program. These parameters are the mass attenuation coefficient (µ/ρ), effective atomic number (Zeff) and electron density (Ne,eff). In addition, the macroscopic effective removal cross-sections (∑R) for fast neutron have been calculated. The dependence of different parameters on incident photon energy and chemical content has been discussed. Among the selected glass systems TeO2-WO3 and TeO2-B2O3 showed superior shielding properties for γ-ray and neutron, respectively. It had been shown that the selected glass systems have higher values of the mass attenuation coefficients (µ/ρ) than concretes and 0.7 SiO2:0.3BaO glass. These results indicate that tellurite glasses can be used as radiation shielding materials.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Phase-shifts determination for nucleon-nucleon scattering using velocity-dependent potentials

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    The S-wave time-independent Schrödinger equation with an isotropic velocity-dependent potential is considered .We have used perturbation theory to calculate the scattering phase shifts when the energy is changed by a small amount ΔE from an arbitrary unperturbed value E0. The validity of our results were tested by comparing the perturbed phase shifts to those obtained exactly by solving Schrödinger equation. We assumed the local potential to have the form of a finite square well and the velocity dependent part of the potential to have the form of a Yukawa potential.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

    Simulation of shielding parameters for TeO 2 -WO 3 -GeO 2 glasses using FLUKA code

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    This paper aimed to report the results on the investigation of photon attenuation parameters for TeO 2 -WO 3 -GeO 2 glasses using FLUKA Monte Carlo code. In order to test the validity of the present code, the computational values of mass attenuation coefficients have been in confirmation with those of both previously published experimental data (MoO 3 -B 2 O 3 -Bi 2 O 3 ) and XCOM database at various energies between 356 and 1330 keV. The relative deviation between FLUKA and experimental data is below 5.19% while the difference between the present code and XCOM database is found to be almost 2%. Therefore, the estimated results are in good agreement to each other and exhibited that FLUKA simulation is an alternative technique in determining the shielding performance of the present glass system. Additionally, mean free path and half-value layer results were calculated and it was concluded that among the selected glasses, TeWGe5 sample has superior shielding effectiveness

    Evaluation of radioprotection properties of some selected ceramic samples

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    In this study, the gamma radiation attenuation features of barium zirconat, barium titanate (IV), magnesium nitride, barium pyrophosphate and silicon carbide were studied using the narrow beam geometrical setup in the energy range of 81 keV–1333 keV. The mass attenuation coefficients have been measured and then used to obtain half value layers, mean free paths and effective atomic numbers of the present materials. It is found that the change in the mass attenuation coefficient is considerable for low photon energies (between 81 and 276 keV), whereas the change in this parameter is comparatively small between 303 and 835 keV photon energies. At high energies (1173, 1275 and 1333 keV), the results showed that the mass attenuation coefficient values for all samples are almost the same which revealed that the present ceramics does not have a significant effect on the amount of attenuation of photon at higher energies. The radiation protection efficiency results revealed that BaZrO3 has the maximum capability in attenuation of gamma photons followed by BaTiO3 and Ba2P2O7, especially at low energies. Keywords: Gamma radiation, Attenuation, Ceramic, Effective atomic number, Radiation protection efficienc

    Tailored spectroscopic characteristics of a new type of CuO nanoparticles-inserted borate glass system: Samarium concentration tuning effect

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    The demand for new glass hosts with emergent properties is constantly growing for various miniaturized applications. Thus, some new types of Sm2O3-activated strontium-telluro-alumino-magnesium-borate glasses with copper oxide nanoparticles (CuONps) insertion were made using melt-quenching approach. The obtained glasses were characterized to determine the effects of Sm2O3 concentration changes on their thermal, structural, and luminescence properties. XRD, FTIR, and HRTEM analyses of the samples verified their glassy nature, presence of different functional units and CuONps, respectively. DTA analysis showed excellent thermal stability of these glasses with a stability factor as much as 125 °C. The optical absorption properties of the glasses were highly sensitive to Sm3+ concentrations variation. The Judd-Ofelt intensity parameters of the glasses with and without CuONps followed the trend of Ω6˃Ω4˃Ω2 and Ω4˃Ω6˃Ω2, respectively. These glasses displayed 4 visible luminescence bands at 561, 598, 645, and 705 nm corresponding to 4G5/2 → 6H5/2, 4G5/2 → 6H7/2, 4G5/2 → 6H9/2, and 4G5/2 → 6H11/2 transitions in Sm3+. In addition, branching ratio above 80% and stimulated emission cross-section up to 135.82 × 10−23 cm2 were achieved. The stimulated emission cross-section and optical gain were enhanced due to the inclusion of CuONps in the glasses. These glasses may be useful for solid state laser and optical amplifier development

    Radiation parameterizations and optical characterizations for glass shielding composed of SLS waste glass and lead-free materials

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    The novelty in the present search, the Soda-Lime-Silica (SLS) glass waste to prepare free lead glass shielding was used in order to limit the accumulation of glass waste, which requires extensive time to decompose. This also saves on the consumption of pure SiO2, which is a finite resource. Furthermore, the combining of BaO with Bi2O3 into a glass network leads to increased optical properties and improved attenuation. The UV–Visible Spectrophotometer was used to investigate the optical properties and the radiation shielding properties were reported for current glass samples utilizing the PhysX/PDS online software. The optical property results indicate that when BaO content increases in glass structure, the Urbach energy ΔE, and refractive index n increases while the energy optical band gap Eopt decreases. The result of the metallisation criteria (M) revealed that the present glass samples are nonmetallic (insulators). Furthermore, the radiation shielding parameter findings suggest that when BaO was increased in the glass structure, the linear attenuation coefficient and effective atomic number (Zeff) rose. But the half-value layer HVL declined as the BaO concentration grew. According to the research, the glass samples are non-toxic, transparent to visible light, and efficient radiation shielding materials. The Ba5 sample is considered the best among all the samples due to its higher attenuation value and lower HVL and MFP values, which make it a suitable candidate as transparent glass shield shielding

    Intense up-conversion luminescence from Dy3+-doped multi-component telluroborate glass matrix: Role of CuO nanoparticles embedment

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    This paper reports an intense up-conversion luminescence from Dy3+-doped strontium-telluro-alumino-magnesium-borate glasses for the first time. The samples were made via the melt-quenching method and characterized to determine the influence of various CuO nanoparticles contents change on their up-conversion emission traits. Absorption spectral data were used to calculate the Judd-Ofelt intensity parameters. The sample without CuO nanoparticles revealed two intense photoluminescence up-conversion emission peaks at 478 and 570 nm. In addition, CuO nanoparticles-activated sample displayed about 1.4-fold up-conversion emission intensity improvement due to strong light absorption in the visible to the infrared region at 799 nm excitation. The stimulated emission cross-section of the CuO nanoparticles-activated glasses was increased from 102.4 × 10−23 to 1301.1 × 10−23 cm2 (nearly 10-fold amplification) while the branching ratio was reduced to 66.9%. Thus, CuO nanoparticles as an additive in the current glass matrix enhanced the up-conversion emission and strengthened the associated nonlinear optical properties. CIE 1931 color matching revealed the influence of CuO in modifying the up-conversion color coordinates, thereby improving the white color purity. The achieved up-conversion emission coupled with the color tunability of the proposed glasses may be advantageous for the up-conversion UV tunable laser making

    Photon parameters for gamma-rays sensing properties of some oxide of lanthanides

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    In the present research work, the mass attenuation coefficients (μm) representing the interaction of gamma photons with some oxide of lanthanides (Lu2O3Yb2O3, Er2O3, Sm2O3, Dy2O3, Eu2O3, Nd2O3, Pr6O11, La2O3 and Ce2O3) were investigated using WinXCom software in the wide energy range of 1 keV–100 GeV. The calculated values of μm afterwards were used to evaluate some gamma rays sensing properties as effective atomic effective atomic numbers (Zeff), effective electron densities (Nel), half value layer (HVL) and mean free path (MFP). The computed data observes that, the Lu2O3 shown excellent γ-rays sensing response in the broad energy range. At the absorption edges of the high elements present in the lanthanide compounds, more than a single value of Zeff were found due to the non-uniform variation of µm. Comparisons with experiments wherever possible have been achieved for the calculated µm and Zeff values. The calculated properties are beneficial expanded use of designing in radiation shielding, gas sensors, glass coloring agent and in electronic sensing devices. Keywords: Oxide of lanthanides, Gamma ray sensors, Effective atomic numbers, Half value laye
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