The influence of MgO on the radiation protection and mechanical properties of tellurite glasses

Hanfi, M.Y.,Sayyed, M.I.,Lacomme, E.,Akkurt, I.,Mahmoud, K.A. Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.6

Mechanical moduli, such as Young's modulus (E), Bulks modulus (B), Shear modulus (S), longitudinal modulus (L), Poisson's ratio (σ) and micro Hardness (H) were theoretically calculated for (100-x)TeO₂+x MgO glasses, where x = 10, 20, 30, 40 and 45 mol%, based on the Makishima-Mackenzie model. The estimated results showed that the mechanical moduli and the microhardness of the glasses were improved with the increase of the MgO contents in the TM glasses, while Poisson's ratio decreased with the increase in MgO content. Moreover, the radiation shielding capacity was evaluated for the studied TM glasses. Thus, the linear attenuation coefficient (LAC), mass attenuation coefficient (MAC), transmission factor (TF) and half-value thickness (𝚫_0.5) were simulated for gamma photon energies between 0.344 and 1.406 MeV. The simulated results showed that glass TM10 with 10 mol % MgO possess the highest LAC and varied in the range between 0.259 and 0.711 cm^-1, while TM45 glass with 45 mol % MgO possess the lowest LAC and vary in the range between 0.223 and 0.587 cm^-1 at gamma photon energies between 0.344 and 1.406 MeV. Furthermore, the BXCOM program was applied to calculate the effective atomic number (Z_eff), equivalent atomic number (Z_eq) and buildup factors (EBF and EABF) of the glasses. The effective removal cross-section for the fast neutrons (ERCSFN, ∑_R) was also calculated theoretically. The received data depicts that the lowest ∑_R was achieved for TM10 glasses, where ∑_R = 0.0193 cm² g^-1, while TM45 possesses the highest ERCSFN where ∑_R = 0.0215 cm² g^-1.

Physical characterization and radiation shielding features of B2O3-As2O3 glass ceramic

Mohamed Y. Hanfi,Ahmed K. Sakr,A.M. Ismail,Bahig M. Atia,Mohammed S. Alqahtani,K.A. Mahmoud 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.1

The synthetic B2O3eAs2O3 glass ceramic are prepared to investigate the physical properties and the radiation shielding capabilities with the variation of concentration of the As2O3 with 10, 20, 30, and 40%, respectively. XRD analyses are performed on the fabricated glasseceramic and depicted the improvement of crystallinity by adding As2O3. The radiation shielding properties are studied for the B2O3eAs2O3 glass ceramic. The values of linear attenuation coefficient (LAC) are varied with the variation of incident photon gamma energy (23.1e103 keV). The LAC values enhanced from 12.19 cm1e37.75 cm1 by raising the As2O3 concentration from 10 to 40 mol% at low gamma energy (23.1 keV) for BAs10 and BAs40, respectively. Among the shielding parameters, the halfevalue layer, transmission factor, and radiation protection efficiency are estimated. Furthermore, the fabricated samples of glass ceramic have low manufacturing costs and good shielding features compared to the previous work. It can be concluded the B2O3eAs2O3 glass ceramic is appropriate to apply in X-ray or low-energy gamma-ray shielding applications.

The radioactivity levels and beta dose rate assessment from dental ceramic materials in Egypt

Hasabelnaby Mohamed,Hanfi Mohamed Y.,El-Gamal Hany,El Gindy Ahmed H.,Khandaker Mayeen Uddin,Salaheldin Ghada 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.9

There is a lack of available data on the radioactivity levels of these materials, despite the potential risks they may pose to patients, dental technicians, and dentists. A total of forty samples were collected from different dental markets in Egypt. Using an NaI(Tl) detector, the gamma-ray spectrometer measured the activity levels of uranium-238, radium-226, thorium-232, and potassium-40. The findings revealed that the mean concentration of 238U (below the minimum detectable activity, MDA), 226Ra (135 ± 5 and 132 ± 5 Bq/kg), 232Th (187 ± 4 and 243 ± 8 Bq/kg), and 40K (1560 ± 52 and 2501 ± 89 Bq/kg) in feldspar and zirconia (ZrO2) dental ceramic samples, respectively, were all within the limits established by the International Organization for Standardization (ISO) and the European Commission (EC). The use of feldspar and zirconia dental ceramics to restore all teeth would result in an estimated maximum beta dose of 1.5 mGy/year to the oral tissue. The results suggest that there is no cause for concern regarding any additional beta dose to the oral cavity from the use of feldspar and zirconia dental ceramics.

Dielectric relaxation of chlorinated polyvinyl chloride (CPVC) stabilized with cyanoguanidine

Salah Mahrous,Taha A. Hanfy,Maged S. Sobhyv 한국물리학회 2007 Current Applied Physics Vol.7 No.6

Dielectric spectra of CPVC stabilized with cyanoguanidine were studied in the temperature range 300450 K and frequency range10 kHz to 1 MHz. In these conditions, only one clear dielectric relaxation band (a-type) associated with dipolar polarization wasobserved. Dielectric losses was found to directly proportional to the number of dipoles (N) which reects the orientational distributionof polymer chains in the amorphous region, at which dielectric losses concerned. Calculations of the dielectric modulusM0(T) at lowtemperature indicate that there is a role of the electrode polarization in the relaxation process. Dielectric loss data were used to calculatethe activation enthalpy by two dierent methods, the obtained value was. 450 kJ/mol.

Poole -Frenkel conduction in polyvinyl chloride stabilized with dibutylin laurate-maleate

Salah Mahrous,T.A.Hanfy 한국물리학회 2004 Current Applied Physics Vol.4 No.5

Electric conduction in PVC-stabilized with dibutylin lauratemaleate has been investigated. In the low voltage region, theconduction was found to be due to thermally generated carriers. At higher voltages, the conduction mechanism was identied asPooleFrenkel type. The charge carriers injected on the polymer surface from the electrodes was found to disappear and become thesource of thermally stimulated discharge (TSD) current.

Assessment of radioactivity levels and radiation hazards in building materials in Egypt

Ahmed E. Abdel Gawad,Mohamed Y. Hanfi,Mostafa N. Tawfik,Mohammed S. Alqahtani,Hamed I. Mira Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.2

Different degrees of natural radioactivity found in quartz can have negative consequences on health. Quartz vein along the investigated Abu Ramad area, Egypt, had its natural radioactivity assessed. The HPGe spectrometer was used to determine the role played by the radionuclides ²³⁸U, ²³²Th, and ⁴⁰K in the gamma radiation that was emitted, and the results showed that these concentrations are 484.64 ± 288.4, 36.8 ± 13.1 and 772.2 ± 134.6 Bq kg^-1 were higher than the corresponding reported global limits of 33, 45, and 412 Bq kg^-1 for each radionuclide (²³⁸U, ²³²Th, and ⁴⁰K). Among the radiological hazard parameters, the excess lifetime cancer risk (ELCR) is estimated and it's mean value of ELCR (1.2) is higher than the permissible limit of 0.00029. The relationship between the radionuclides and the associated radiological hazard characteristics was investigated based on multivariate statistical methods including Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA). According to statistical research, the radioactive risk of quartz is primarily caused by the ²³⁸U, ²³²Thand ⁴⁰K. Finally, applying quartz to building materials would pose a significant risk to the public.

Threats of Changing Technology and Increasing Climate Variations: An Empirical Study of Business Opportunities and Challenges by KSA Firms

Divya Rana,Fathimunisa Begam Afsar Hanfy 대한산업공학회 2019 Industrial Engineeering & Management Systems Vol.18 No.3

There has been an increase in demands where businesses are now required to respond to the threat of changing technology and the gradual increase in climatic variations, on the basis of the influential position that businesses are known to enjoy within the global community. If businesses are able to integrate people, technology, strategy and procedures while implementing initiatives that respond to climatic changes, it would result in creation of value in the long-term, which is a powerful too. However, there is a need to understand the threats that are presented by changing technology and climatic variations, which is the key focus of this research. The objective was to identify the business opportunities and challenges faced by businesses in KSA in the face of changing technology and climate change and whether there was an association between the two. The research adopted a quantitative methodology where the findings revealed that climatic variations can substantially impact businesses in terms of financial reporting, organizational reputation, legal responsibilities and supply chain and operations. It also found that business performance was also positively influenced by changing technology. The findings also revealed that changes in technology could also positive influence climatic variations. Thus, it can be concluded that changing technology and climatic variations bright forth substantial risks that could present opportunities as well as significant challenges for businesses operating in KSA.

Radiological hazards assessment associated with granitoid rocks in Egypt

Abdel Gawad Ahmed E.,Masoud Masoud S.,Khandaker Mayeen Uddin,Hanfi Mohamed Y. 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.6

The present study aimed to assess the radioactive hazards associated with the application of granitoid rocks in building materials. An HPGe spectrometer was used to detect the levels of the radioactive elements uranium-238, thorium-232, and potassium-40 in the granitoid rocks. The results showed that the levels of these elements were lower (38.32 < 33 Bq kg 1), comparable (47.19–45 Bq kg-1) and higher (992.26 ≫> 412 Bq kg 1) than the worldwide limits for 238U, 232Th, and 40K concentration, respectively. The exposure to gamma radiation of granitoid rocks was studied by various radiological hazard variables like the absorbed dose rate (Dair), the outdoor and indoor annual effective dose (AEDout and AEDin), and excess lifetime cancer risk (ELCR). A variety of statistical methods, including Pearson correlation, principal component analysis (PCA), and hierarchical cluster analysis (HCA) was used, to study the relationship between the radioactive elements and the radiological hazards. According to statistical analysis, the main radioactive risk of granitoid rocks is contributed to by the elements uranium-238, thorium-232, and potassium-40. Granitoid rocks can be applied in building materials, but under control to prevent risk to the public.