Introduction:: Employees may be exposed to different kinds of ionizing radiation at work. When ionizing radiation interacts with human cells, it can cause damage to the cells and genetic material. Therefore, one of the scientists' primary objectives has always been to create the best radiation-shielding materials. Glass could offer promising shielding material resulting from the high flexibility of composition, simplicity of production, and good thermal stability. Materials and Methods:: The melt-quenching technique was used to create a glass having the following formula: 50%P2O5+20%Na2O+20%Fe2O3+10%X, where X = As2O3, SrO, BaO, CdO, and Sb2O3 mol %. The impact of the different heavy metal additions on the structure of the glass networks was studied using FTIR spectroscopy. Glass's ability to attenuate neutrons and/or charged particles has been theoretically investigated. The performance of the developed glass as a shield was examined by a comparison against commercial glass (RS 253 G18), ordinary concrete (OC), and water (H2O). Results:: For charged particle radiations (Electrons, Protons, and Alpha), the shielding parameters like the mass stopping power, the projected range, and the effective atomic number were evaluated, where S5/Sb glass achieves the best performance. In the case of Neutrons, the results values reveal that S3/Ba glass ( Σ! = 0.105) is the best-modified glass for neutron shielding. Conclusion:: Among all the investigated glasses, S5/Sb glass composition has a smaller range and provides superior protection against charged particles. In contrast, the S3/Ba glass composition is a superior choice for shielding against neutron radiation.

This work discusses various fuel pellet designs loaded with different types and concentrations of burnable absorbers to suppress the excess reactivity at the early stage of the fuel life in the VVER-1200 fuel assembly. MCNPX, V. 2.7 with the CINDER 90 fuel depletion code was utilized to analyze the neutronic characteristics of the proposed cases. Concentric shells (CS) of integral burnable absorbers are investigated in the fuel tube. Gadolinium and Erbium at different concentrations are investigated in the CS at different operation cycles to manage the excess reactivity. Gadolinium and boron as traditional burnable absorbers (BAs) are investigated in the standard fuel assembly to compare their results with the suggested cases. The infinity multiplication factor (kinf), the concentrations of the fuel composition, reactor-grade plutonium (rgPu), minor actinides (MAs) and some important fission products poisoned were studied with burnup. The radial power and thermal neutron flux distribution through one-six of the VVER-1200 assembly have been analyzed to distinguish the optimum BA and design for flattening the power profile. The neutronic analysis indicates that using Er2O3 in a concentric shell of a fuel pellet is an interesting method for reactivity management.

The current study investigates the physical structural and radiation shielding capabilities of a newly developed glass system incorporating silica extracted from rice straw ash (RSA). The purity and chemical composition of the silica are determined using XRF. XRD confirms the amorphous character of the synthesized glass. Moreover, molar volume, optical parameters, and density will be investigated. Gamma (gamma)-rays shielding parameters like half-value layer, mass attenuation coefficient, the effective atomic number, and the mean free path are experi-mentally measured across a broad range of gamma-ray energies (81 keV-1408 keV) emitted from 152Eu, 133Ba, 137Cs, and 60Co radioactive isotopes. The exposure buildup factor will be evaluated with the geometric pro -gression fitting approximation. In addition, Phy-X/PSD software is used to calculate theoretically the former shielding parameters. A good agreement between theoretical and experimental values has been revealed. Finally, a comparison was made to investigate the potential use of our glass to replace the common shielding material like concrete (ordinary and hematite-serpenite), commercial glass (RS 253), and the newly developed Ag2O doped boro-tellurite glass. The newly prepared glass has higher MAC, Zeff values and lowered HVL and MFP values. These properties make our prepared glass system superior in terms of shielding from gamma-rays.

The current study aimed to fabricate and investigate new glass system incorporating silica from rice straw ash (RSA). The effect of adding different concentrations of bismuth oxide (Bi2O3) on the glass's structure was examined using FTIR. The A.C. conductivity of the prepared glasses over the frequency range (120 Hz 100 kHz) and the temperature range (300-620 oK) have been measured. Based on its electron density, a substance's electrical conductivity can alter as photon energy increases. For the current investigated glasses, the electron density (N-eff) and electrical conductivity relation over the energy range (0.015-10 MeV) were calculated. Glass samples' ability to attenuate radiation such as neutrons, electrons, protons, and alpha particles has been investigated. For neutrons, the effective removal cross-section (Sigma(R), cm(-1)) and the total macroscopic crosssection (Sigma(T), cm(-1)) are calculated. For charged particles like protons (H+) and alpha (He2+), SRIM software has been used to determine the glass Mass Stopping Power (MSP) and the Projected Range (PR). For electrons (beta), MSP and the Continuous Stopping Down Approximation (CSPA) were calculated using ESTAR (NIST). On the other hand, Phy X/Zextra software was used to determine glasses effective atomic numbers (Z(eff)) over a broad energy range. As a result, BSiBi20 glass with the highest Bi2O3 concentrations (20 mol. %) shows superior shielding features for fast neutrons (Sigma(R) = 0.128 cm(-1)) compared to the competitors like ordinary concrete (O. C.). For charged particles, BSiBi20 glass achieves the lowest MSP, CSPA, and the highest Z(eff) values over the entire energy range. The KERMA (Kinetic Energy Released per unit Mass of the Absorbing material) calculations indicated a significant influence on the elemental composition of the glass system in the intermediate photon energy regime.

The present work represents the state-of-art investigation for the effect of the dose deposited by gamma rays on Polyethylene terephthalate (PET) and its biaxially oriented film (BoPET) Samples. Set of Mylar biaxially oriented PET polymer films having a thickness of 10 um. Gamma rays irradiated the samples at different doses (100 to 900 kGy). There is a small signature of gamma-ray effect at absorption bands at 2983 cm–1, 2962 cm–1, and 2950 cm−1, which gives rise to radiation–possible effects. The possible effects may arise from energy deposition within the elements that make up these samples. The results show that chain secession in the PET sample is more likely to occur than in its mirror BoPET samples. The material's response from the macroscopic level to the microscopic level depends on the microscopic pattern of energy deposition. The molecular charge was interpreted based on the thrown light on the influence of molecular polarization on the physical nature of radiation interaction with matter. With respect to PET samples, its carboxyl ions have random distribution relative to the axis of the chain molecule in the amorphous phase. In contrast, BoPET samples have an ordered distribution of carboxyl dipoles in the radial direction. Indeed, the dipole of the BoPET is almost perpendicular to the polymer chain axis, leading to a reduction in energy deposition within the material. As a result, the material becomes more resistant to radiation.

In this paper, the Monte Carlo N-Particle extended computer code (MCNP) were used to design a model of the European Sodium-cooled Fast Reactor. The multiplication factor, conversion factor, delayed neutrons fraction, doppler constant, control rod worth, sodium void worth, masses for major heavy nuclei, radial and axial power distribution at high burnup are studied. The results show that the reactor breeds fissile isotopes with a conversion ratio of 0.994 at fuel burnup 70 (GWd/T), and minor actinides are buildup inside the reactor core. The study aims to check the efficiency of the model on the calculation of the neutronic parameters of the core at high burnup.

The specific activity of U-238 and Th-232, as well as K-40 radionuclides, in twenty-nine investigated medicinal herbs used in Egypt has been measured using a high-purity germanium (HP Ge) detector. The measured values ranged from the BDL to 20.71 ± 1.52 with a mean of 7.25 ± 0.54 (Bq kg−1) for uranium-238, from the BDL to 29.35 ± 1.33 with a mean of 7.78 ± 0.633 (Bq kg−1) for thorium-232, and from 172 ± 5.85 to 1181.2 ± 25.5 with a mean of 471.4 ± 11.33 (Bq kg−1) for potassium-40. Individual herbs with the highest activity levels were found to be 20.71 ± 1.52 (Bq kg−1) for uranium-238 (H4, Thyme herb), 29.35 ± 1.33 (Bq kg−1) for thorium-232 (H20, Cinnamon), and 1181.2 ± 25.5 (Bq kg−1) for potassium-40 (H24, Worm-wood). (AACED) Ingestion-related effective doses over the course of a year of uranium-238 and thorium-232, as well as potassium-40 estimated from measured activity concentrations, are 0.002304 ± 0.00009 (minimum), 0.50869 ± 0.0002 (maximum), and 0.0373 ± 0.0004 (average)(mSv/yr). Radium equivalent activity (Raeq), annual gonadal dose equivalent (AGDE), absorbed gamma dose rate (Doutdoor, Dindoor), gamma representative level index (I), annual effective dose (AEDtotal), external and internal hazard index (Hex, Hin), and excess lifetime cancer risk were determined in medicinal plants (ELCR). The radiological hazards assessment revealed that the investigated plant species have natural radioactivity levels that are well within the internationally recommended limit. This is the first time that the natural radioactivity of therapeutic plants has been measured in Egypt. In addition, no artificial radionuclide (for example, 137Cs) was discovered in any of the samples. Therefore, the current findings are intended to serve as the foundation for establishing a standard safety and guideline for using these therapeutic plants in Egypt.

A mixture of deuterium (D) and tritium (T) is the most likely fuel for fusion reactors and hence the D(d, n)3He and T(d, n)4He fusion reactions are the ones that will fire fusion reactors in the future. Both of the fusion reactions produce neutrons which escape form the reactor core and can be measured directly outside the core. As the neutrons have large mean free path and neutral charge, they readily carry information about the burning fusion plasma from inside to outside the reactor core without being affected by electric ormagnetic fields. From the produced neutrons of the D(d, n)3He and T(d, n)4He fusion reactions, the neutron yield of each reaction and the neutron yield ratio of the two reactions are calculated. This ratio is of critical importance for controlling the fusion fuel burning which is a high priority issue for fusion reactor performance. Because it is very difficult to measure this ratio experimentally, accurate theoretical calculations of the neutron yield ratio besides the related deuterium and tritium energy spectra in the fusion plasma are needed. In the present work, neutron yields of the D(d, n)3He and T(d, n)4He fusion reactions have been calculated using the MCUNED, the ENEA-JSI, the DDT codes and the Geant4 toolkit. The related deuterium and tritium energy spectra have been calculated by the MCUNED code. The relation between the ion temperature and the neutron yield in the imploded fusion plasma is discussed. Calculations are compared to the available experimental data. Comparing to the other codes, the spectrum of the fusion neutrons simulated by the MCUNED is the only one that fit the experimental data.

In this paper, we scrutinize the availability of borosilicate glassy systems doped with mixed heavy metals as radiation shielding attenuators; for this purpose, a glass system [20SiO(2) + 54B(2)O(3) +1NiO + xBi(2)O(3) + (25-x) BaO], x = 5, 10, 15, 20 and 25 mol.%] was prepared using melt quenching procedures. The optical transmittance of the glassy specimens was measured in the ultraviolet-visible range to study the influence of bismuth oxide on the transparency. The density and molar volume of the prepared glasses were increased from 3.31 to 4.51 g/cm(3) and from 31.47 to 36.96 cm(3)/mole, respectively, as the concentration of Bi2O3 increased from 5 to 25 mol%. Moreover, the radiation shielding parameters, such as the mass and linear attenuation coefficients, the total atomic and electronic cross-sections, the effective atomic number, the effective electron density, and the half value layer and tenth value layer of these glasses were experimentally obtained at gamma-ray energies of 0.662, 1.173 and 1.332 MeV. We compared the measured linear attenuation coefficients with those simulated via Geant4 code and computed by XCOM software to ensure the accuracy in the experimental data. For all the current glasses, we found that the maximum linear attenuation coefficient occurred at 0.662 MeV and lied within the range of 0.246-0.365 cm(-1). We also found that the values of both the linear and mass attenuation coefficients increased as Bi2O3 concentration was increased. Additionally, we found that the half value layer for the prepared glasses was smaller for the low energy (0.662 MeV) than the other energies, which confirmed that thin glass samples can shield from low energy photons. In terms of the tenth value layer, we report that the glass sample that contains 25 mol% of Bi2O3 had the smallest TVL. According to the obtained results, it can be stated that the borosilicate glasses doped with mixed heavy metals (BaO and Bi2O3) appeared to be transparent to the visible range and have good gamma-ray shielding features.

Monte Carlo N‐Particle eXtended (MCNPX) computer code was used to design heterogeneous and homogeneous models for the inner and the outer assemblies of a 3600 MWth fast breeder reactor cooled by sodium which is used for next-generation IV reactors. The purpose of the models is to test the adequacy of the lattice homogenization methods for calculations of the neutronic parameters of the assemblies. The multiplication factor, power distributions, and isotopic transmutation were studied and compared using both heterogeneous and homogeneous models. The results indicate that the two models are in good agreement in all cases.

In this paper, neutronic calculations and the core analysis of the VVER-1000 reactor were performed using MCNP6 code together with both ENDF/B-VII.1 and ENDF/B-VIII libraries. The effect of thorium introduction on the neutronic parameters of the VVER-1000 reactor was discussed. The reference core was initially filled with enriched uranium oxide fuel and then fueled with uranium-thorium fuel. The calculations determine the delayed neutron fraction βeff, the temperature reactivity coefficients, the fuel consumption, and the production of the transuranic elements during reactor operation. βeff and the Doppler coefficient (DC) are found to be in agreement with the design values. It is found that the core loaded with uranium and thorium has lower delayed neutron fraction than the uranium oxide core. The moderator temperature coefficients of the uranium-thorium core are found to be higher than those of the uranium core. Results indicated that thorium has lower production of minor actinides (MAs) and transuranic elements (mainly plutonium isotopes) compared with the relatively large amounts produced from the uranium-based fuel UO2.

The structural configuration of graphene oxide and its surface reactivity were investigated experimentally and clarified on the bases of time-independent density functional calculations (DFT). The physical structure was examined by transmission electron microscopy, infrared absorption, and X-ray diffraction parallel to radial distribution analysis. Surface reactivity was examined using N-2-adsorption at 77 K and the kinetic of the adsorption of Ni2+, Cd2+, and Pb2+ ions at 300 K. The lattice structure of the material was hexagonal with unit cell a = 2.455 angstrom and c = 8.64 angstrom and with layer-layer distance of 4.32 angstrom. This structure is undulated in response to existence of oxygen atoms that shape surface topological imperfections and breaks the planner regularity. The undulation distance comprises 0.3 angstrom. The specific surface area was found 60.3 m(2)/g with about 50% of this area were available to adsorption of 2+ ions due to surface polarization. The vibration frequencies observed in FTIR are identified by DFT calculations and showed that the structure acts as an extended quantum system for which Pauli blocking prevents existence of two modes of marginal hydrogen vibrations within the same sheet.

Abstract Excitation functions were measured by the activation method using the stacked-foil technique for the natMo(p,x)93(m+g),94m,g,95m,g,96(m+g),99mTc, 92m,95Nb reactions up to 18 MeV. The experimental results were compared with literature data and theoretical results from EMPIRE-3.2.2 code and TENDL. Special attention was paid to the 100Mo(p,2n)99mTc reaction which is very promising for the production of 99mTc at a cyclotron. In order to optimize the production conditions of some medically important Tc isotopes, the integral yields were estimated based on the measured cross sections.

Atmospheric Boundary Layer (ABL) height (h) is one of the basic criteria for describing its structure. ABL measurements, parameters and predictions have numerous practical and theoretical implementations as forecast of pollutant concentrations, surface temperature, expansion of disturbance measurements or in climate models and numerical weather prediction. The height of the mixing layer is difficult to be measured; therefore, mathematical methods are introduced to calculate this layer and different FORTRAN programs have been developed to define the height of ABL on an hourly basis through the year. The analysis of the results showed that the variation of the height of the mixing layer for different seasons depends on the type of the dominant stability class and the value of wind speed, where the rise of the mixing layer in winter and autumn months may be related to increased frequency of stability conditions in the unstable and slightly unstable atmosphere On the other hand, when the stable conditions are dominant, the height of the mixing layer remains smaller. The boundary layer ozone is a standard contaminant because of its harmful effects on living organisms and plants. It also has an active role in atmospheric chemistry and climate change; therefore, monthly and seasonal variation of the surface ozone O-3 concentration and its effects on the atmospheric boundary layer are measured for the first time at a coastal site in Egypt in the year 2013.

Introduction: In medulloblastoma patients craniospinal irradiation is an important element the treatment. Our study aimed to evaluate the effect of absorbed dose to organs at risk using the hybrid intensity-modulated radiation therapy (IMRT) versus three-dimensional conformal radiotherapy (3DCRT) for craniospinal irradiation (CSI) in average risk medulloblastoma patients. Materials and Methods: In this study, thirteen medulloblastoma patients were included. The prescribed total dose to the planning target volume (PTV) was 23, 40 Gy in 13 fractions. Two radiotherapy techniques, three dimensional conformal radiotherapy (3DCRT) and hybrid intensity modulated radiotherapy (IMRT) were used to treat these patients. The coverage of the Target was evaluated using the D mean, D95%, D2%, D98% and V95%. Other parameters were also compared such as Integral dose (ID), Homogeneity index (HI) and doses to the organs at risk (OARs). Results: There was no significant difference in the mean dose received by the PTV-Brain or the dose received by 95% and 98% of PTV volume using the two techniques. For PTV-Spine, the percentage volume receiving 95% of the total dose increased significantly in the hybrid IMRT technique compared to the conformal technique. So, hybrid IMRT plan achieved the best coverage for PTV spine. Lower dose for OAR was delivered by 3DCRT, except the heart and thyroid, hybrid IMRT achieved better sparing. All plans resulted in the same dose homogeneity index (DHI) for PTV-Brain. For PTV-Spine, hybrid IMRT technique achieved better dose homogeneity compared to 3DCRT technique (1.09 vs. 1.12; p > 0.05). Conclusions: hybrid IMRT technique can be realized on conformal technique because it achieved better dose coverage for the (PTV) and organ at risk (OAR). 3DCRT reduced mean dose to most OARS, except the heart and thyroid. Therefore, the hybrid IMRT technique may be a CSI treatment alternative to 3DCRT.

Density of states and geometrical structures of modified Lead zirconate titanate are investigated using density functional theory within local density approximation. The electronic properties and bond length variation have been studied in terms of electronic structure and bonding mechanism principles respectively. Hybridization between Ti 3d - O 2p states and ferroelectric distortion have been addressed as a theoretical approach, to rule the improvement of ferroelectric properties of Lead zirconate titanate. The analysis of Ga, Tl modified Lead zirconate titanate were found to diminish the hybridization between Ti 3d - O 2p states, the relaxed behavior lead to the reversal of the known ferroelectric distortion. Y, Ho, Yb and Lu modified Lead zirconate titanate compounds have a tendency to intense the ferroelectric stability, its exhibit higher hybridization between Ti 3d - O 2p states than pure Lead zirconate titanate, also the arrangement of the ions distortions is strongly the same as the more favoured ferroelectric states of Lead zirconate titanate.

The present work studies the effect of introducing MOX fuel on Westinghouse AP1000 neutronic parameters. The neutronic calculations were performed by using the MCNP6 code with the ENDF/B-VII.1 library and the new release of the ENDF/B-VIII, the AP1000 core with three 235U enrichment zones (2.35 %, 3.40 %, and 4.45 %). The obtained results showed that the simulated model for the AP1000 core satisfies the optimization criteria as a Westing- house reference. The results which included: effective multiplication factor, keff, delayed neutron fraction, beff, excess reactivity, rex, shutdown margin, temperature reactivity coefficients, whole core depletion, neutron flux, power peaking factor and core power density, were calculated and compared with the available published results. The keff in the cold zero power was found to be 1.20495 and 1.20247 with the ENDF/B-VII.1 and the ENDF/B-VIII libraries, respectively, which matches the value of 1.205 presented in the AP1000 Design Control Document for the UO2 fuel core. On the other hand, keff in the cold zero power was found to be 1.19988 and 1.19860 for MOX core with the ENDF/B-VII.1 and the ENDF/B-VIII libraries, respectively, which show good reception and confirm the safety of the design and efficient modeling of AP1000 reactor core.

Excitation functions were measured by the activation method using stacked-foil technique for the natSr(p,xn)88,87m,g,86m,gY reactions up to 18 MeV. The experimental results were compared with the theoretical data from EMPIRE-3.2 code and TENDL. Integral yields of 88,87m,g,86m,gY were estimated based on the measured cross sections. The optimum energy range for the production of the important isotope 88Y is Ep = 16→11 MeV, 88Y yield amounts to about 3 MBq/µAh.

The attenuation of gamma-ray radiation depends mainly on the energy of the incident gamma photon, the effective atomic number, density of the elements in the shielding material and the thickness of such shield.However, in this work, mass and linear attenuation coefficients, effective atomic number and electron density, mean free paths, half value layer and 10 th value layer of some barium-bismuth-boro-silicate glasses were obtained at gamma-ray photon energies of 0.662, 1.173 and 1.332 MeV, by using Win-XCOM computer program.The obtained data were then compared with the experimental data.The obtained theoretical results were found in good agreement with these obtained experimentally.According to the obtained results, it can be stated that, Boro-silicate glasses containing mixed heavy metal oxides (BaO and Bi2O3) appeared to be transparent and have good gamma-ray shielding properties.But the best glass sample that can act as good attenuator is that containing 25 mol% Bi2O3, at low gamma-ray energy photons.