scholarly journals Synthesis of Pb3O4-SiO2-ZnO-WO3 glasses and their fundamental properties for gamma shielding applications

2021 ◽  
Author(s):  
kh. S. Shaaban ◽  
E. A Abdel Wahab ◽  
Sultan Alomairy ◽  
C. Mutuwong ◽  
Mohammed Sultan Al-Buriahi
Keyword(s):  
Gamma Rays ◽  
Glass Sample ◽  
Theoretical Calculations ◽  
Glass System ◽  
Lead Silicate ◽  
Fundamental Properties ◽  
Prepared Glass ◽  
Shielding Properties ◽  
Polaron Radius ◽  
Quench Method

Abstract In this research, we prepared zinc lead silicate glass system with the composition 35Pb3O4-60SiO2- (5-x) ZnO-xWO3 (0 ≤ x ≤ 5 mol %) via the melt-quench method. XRD is explored the nature of the glass system. Ultrasonic velocity, and elastic modulus were experimentally investigated and then the results were confirmed by using the theoretical calculations. It was found that because of molar volume reduction inter-ionic distance\({R}_{i}\), polaron radius \({r}_{p}\), and inter-nuclear distance, \({r}_{i}\)of the investigated glasses are reduced with WO3 content. The basic attenuation factors; mass and linear coefficients denoted by µ/ρ and µ, respectively, were determined employing several simulations for each energy via FLUKA code. As WO3 content increased from 0 to 5 mol %, the µ increased from 0.728 cm− 1 to 0.856 cm− 1 achieving high shielding performance for the sample with x = 5 mol %. At 0.6 MeV with x = 5 mol %, we found that the dose rate of the prepared glass system decreases from 2.35 × 107 R/h at 1 mm to 4.71 × 106 R/h at 4 mm. The values of MFP and HVL are lower than those of the conventional photon shields indicating that our prepared glass samples (especially G5 glass sample) have promising shielding properties to use for x/gamma rays applications.

Investigation of γ ray shielding, structural and dissolution rate studies of alkali based bismuth borate glass systems with MoO3 added

2019 ◽  
Vol 107 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Mridula Dogra ◽  
K.J. Singh ◽  
Kulwinder Kaur
Keyword(s):  
Dissolution Rate ◽  
Strong Dependence ◽  
Mass Attenuation Coefficient ◽  
Radiation Shielding ◽  
Glass System ◽  
Nuclear Radiation ◽  
Amorphous Network ◽  
Prepared Glass ◽  
Γ Ray ◽  
Shielding Properties

Abstract Bi2O3–B2O3–Li2O–K2O–MoO3 glass system has been synthesized using melt-quenching technique. γ ray shielding properties have been evaluated in terms of mass attenuation coefficient at photon energies 356, 662 and 1173 keV. These shielding parameters are also compared with standard nuclear radiation shielding material “barite concrete” at the same photon energies. Most of our prepared samples show better γ ray shielding properties as compared to barite concrete at the same photon energies. Density, molar volume, XRD, FTIR and Raman studies have been employed to study the structural properties of the prepared glass system. Different structural groups such as [BO3], [BO4], [MoO4] and [MoO6] have been detected in the amorphous network. The presence of non-bridging oxygens, bridging oxygens and change of coordination number has been discussed. The optical absorption spectra are recorded in the wavelength range 200–800 nm and optical band gap is calculated which has shown strong dependence on Bi2O3/B2O3 ratio. The samples have also been tested for their durability by measuring dissolution rate properties using distilled water at 90°C. It has been concluded that increase in the content of Bi2O3 in the composition improves durability and γ ray shielding properties of the samples.

scholarly journals Impact of Al2O3 and Dy2O3 Substitution on the Physical, Structural, and Radiation Shielding Properties of Li2O-B2O3 Glass System

2021 ◽  
Vol 50 (10) ◽  
pp. 3127-3138
Author(s):  
Aljewaw O.B. ◽  
Karim M.K.A ◽  
Zaid M.H.M ◽  
Halimah M.K. ◽  
Noor N.M ◽  
...  
Keyword(s):  
Optical Properties ◽  
Xrd Analysis ◽  
Radiation Shielding ◽  
Glass System ◽  
Diffraction Spectrum ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Prepared Glass ◽  
Nir Absorption ◽  
Shielding Properties

A new series of lithium-borate glass systems (23Li2O-72B2O3 in mol%) were synthesized with the substitution of Al2O3 (5 mol.%) as a modifier and doped with 0.3 and 0.5 mol% of Dy2O3. Four series of glasses (S1, S2, S3 and S4) were synthesized via the conventional melt-quenching technique and characterized by using UV-Visible-NIR absorption spectrometer and Fourier transform infrared (FTIR) spectroscopy. The current investigation gives further insight on the structural and optical properties of the samples. The diffraction spectrum obtained from the X-ray Diffraction (XRD) analysis shows no typical peaks in the glass system, which indicates its amorphous phase. The optical properties of Al3+ and Dy3+ ions were evaluated and found that there is a pivot effect for the addition of Al2O3 and Dy2O3 for the glass system. Notably, the sample S2 shows different behaviours for physical, structural, and optical properties compared with other prepared glass samples that can be attributed to the increment of Al2O3. Besides, the physical and ionizing shielding features were investigated for current glass samples. The radiation shielding properties were examined within the energy range of 0.015 until 15 MeV. The sample S4 has the optimum radiation shielding features as a result of the addition of Dy2O3. Hence, the composition attributes a new glass system that can be used in various applications such as radiation dosimeter and photon shielding materials.

scholarly journals Neutron shielding properties of a borated high-density glass

2017 ◽  
Vol 32 (2) ◽  
pp. 120-126 ◽  
Author(s):  
Aly Saeed ◽  
Shazly El ◽  
Mohamed El-Okr ◽  
Ali El-Azm ◽  
Yahia Elbashar ◽  
...  
Keyword(s):  
Gamma Rays ◽  
High Density ◽  
Glass System ◽  
Fast Neutrons ◽  
Geometric Condition ◽  
Linear Attenuation Coefficient ◽  
Barium Borate ◽  
Neutron Shielding ◽  
Shielding Properties ◽  
Slow Neutrons

The neutron shielding properties of a borated high density glass system was characterized experimentally. The total removal macroscopic cross-section of fast neutrons, slow neutrons as well as the linear attenuation coefficient of total gamma rays, primary in addition to secondary, were measured experimentally under good geometric condition to characterize the attenuation properties of (75-x) B2O3-1Li2O-5MgO-5ZnO-14Na2O-xBaO glassy system. Slabs of different thicknesses from the investigated glass system were exposed to a collimated beam of neutrons emitted from 252Cf and 241Am-Be neutron sources in order to measure the attenuation properties of fast and slow neutrons as well as total gamma rays. Results confirmed that barium borate glass was suitable for practical use in the field of radiation shielding.

Simulating the radiation shielding properties of TeO2–Na2O–TiO glass system using PHITS Monte Carlo code

2021 ◽  
Vol 196 ◽  
pp. 110566
Author(s):  
Jamila S. Alzahrani ◽  
Miysoon A. Alothman ◽  
Canel Eke ◽  
Hanan Al-Ghamdi ◽  
Dalal Abdulldh Aloraini ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Radiation Shielding ◽  
Glass System ◽  
Monte Carlo Code ◽  
Shielding Properties

Effects of WO3 on Radiation Shielding Properties of WO3–TeO2 Binary Tellurite Glass System

2021 ◽  
Vol 222 (1) ◽  
pp. 125-135
Author(s):  
S. Ravangvong ◽  
W. Nisspa ◽  
P. Glumglomchit ◽  
P. Amornsophon ◽  
R. Kanuenghet ◽  
...  
Keyword(s):  
Tellurite Glass ◽  
Radiation Shielding ◽  
Glass System ◽  
Shielding Properties

Thermal and Crystallization Behavior of B2O3 – SiO2 – Bi2O3 – TiO2 – Y2O3 Glasses

2021 ◽  
Author(s):  
Kh. S. shaaban
Keyword(s):  
Glass Ceramic ◽  
Xrd Analysis ◽  
Nucleating Agent ◽  
Thermal Parameter ◽  
Glass System ◽  
Present System ◽  
Increasing Trend ◽  
Parameter Values ◽  
Modifier Oxide ◽  
Quench Method

Abstract Glasses with the chemical composition of 52B2O3 – 12SiO2- 26Bi2O3 – (10 - x ) TiO2 - xY2O3, : (0 ≤ x ≥ 10 )prepared using the melt-quench method. The goal of this study is to investigate the structural, thermal, and crystallization characteristics of these samples. XRD analysis has explored the nature of the glass system. Molar volume obtained reduced while the density denotes increased in the present system. FTIR analysis revealed that as Y2O3 replaced by TiO2, because of an increasing trend in bridging oxygens (BOs), structural units and interconnection of modifier oxide tetrahedral increment, while non-bridging oxygens (NBOs) reduce. These glasses' thermal stability investigated using DTA. As the concentration of Y2O3 increased, so the thermal parameter values. The glass-ceramic denoted prepared under controlled heat and investigated using XRD & SEM. Ultrasonic velocities and elastic moduli of glass-ceramic samples increase as internal energy increases. The significance of Y2O3 modifier in the glass system signifies proved. Y2O3 is a powerful nucleating agent that can cause crystallization, assisting in the formation of glass-ceramic phases.

scholarly journals Estimation of the X/γ- ray shielding properties of different glass system using Monte Carlo Simulation

2021 ◽  
Vol 12 (2) ◽  
pp. 1117-1122
Author(s):  
Ayano Shanko, MD, Et. al.
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Attenuation Coefficient ◽  
Mass Attenuation Coefficient ◽  
Radiation Shielding ◽  
Glass System ◽  
Effective Electron ◽  
X Ray ◽  
Shielding Properties ◽  
Mass Attenuation

The aim of the research is to estimate the X-ray shielding properties of different glass systems using Monte Carlo Simulation. X-ray glass is also known as radiation shielding glass. Glass provides protection against the absorption of energy radiation. The shielding layer is formed by a high concentration of lead and barium. The mass attenuation coefficient, the effective atomic number and the effective electron density are used to determine the position of gamma-ray photons in matter. Shield characterization in terms of mass attenuation coefficient (μm), transmission fraction (T), effective atomic numbers (Zeff), half-value layer (HVL) and exposure build-up. factor (EBF) of a glass system is estimated by the Monte Carlo Simulation. The random sampling and statistical analysis are computed using the monte carlo simulation. Various external factors are considered as the input parameters. The different composition of the glass will be examined using the Monte Carlo simulation and the shielding capability would be determined for the various samples.

scholarly journals Study on Interaction of Bi2O3, PbO and BaO in Silicate Glass System at 662 keV for Development of Gamma-Rays Shielding Materials

2011 ◽  
Vol 1 (0) ◽  
pp. 106-109 ◽  
Author(s):  
Natthakridta CHANTHIMA ◽  
Jakrapong KAEWKHAO ◽  
Chittra KEDKAEW ◽  
Weerapong CHEWPRADITKUL ◽  
Artorn POKAIPISIT ◽  
...  
Keyword(s):  
Silicate Glass ◽  
Gamma Rays ◽  
Glass System

scholarly journals Mechanism of genome interrogation: How CRISPR RNA-guided Cas9 proteins locate specific targets on DNA

2017 ◽  
Author(s):  
A. A. Shvets ◽  
A. B. Kolomeisky
Keyword(s):  
Theoretical Calculations ◽  
Publication Date ◽  
Target Search ◽  
Discrete State ◽  
Fundamental Properties ◽  
Protospacer Adjacent Motif ◽  
Associated Proteins ◽  
Reversible Transitions ◽  
Molecular Aspects ◽  
Dynamic Description

AbstractThe ability to precisely edit and modify genome opens endless opportunities to investigate fundamental properties of living systems as well as to advance various medical techniques and bioengineering applications. This possibility is now close to reality due to a recent discovery of the adaptive bacterial immune system, which is based on clustered regularly interspaced short palindromic repeats (CRISPR)-associated proteins (Cas) that utilize RNA to find and cut the double-stranded DNA molecules at specific locations. Here we develop a quantitative theoretical approach to analyze the mechanism of target search on DNA by CRISPR RNA-guided Cas9 proteins, which is followed by a selective cleavage of nucleic acids. It is based on a discrete-state stochastic model that takes into account the most relevant physical-chemical processes in the system. Using a method of first-passage processes, a full dynamic description of the target search is presented. It is found that the location of specific sites on DNA by CRISPR Cas9 proteins is governed by binding first to protospacer adjacent motif (PAM) sequences on DNA, which is followed by reversible transitions into DNA interrogation states. In addition, the search dynamics is strongly influenced by the off-target cutting. Our theoretical calculations allows us to explain the experimental observations and to give experimentally testable predictions. Thus, the presented theoretical model clarifies some molecular aspects of the genome interrogation by CRISPR RNA-guided Cas9 proteins.Insert Received for publication Date and in final form Date.

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