Browsing by Author "OLARINOYE, OYELEKE"

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A comparative study of the radiation dose response of (ZnO)x(TeO2)1-x thin films for high energy X-ray application
(ELSEVIER, 2025) M.M. Idris; OLARINOYE, OYELEKE; Kolo, M. T.,; S.O. Ibrahim; U. Rilwanc; M.I. Sayyedd
The current research work determines the X-ray radiation effects on the current–voltage (I-V) characteristics of zinc oxide-doped tellurium dioxide thin film as a dosimetric material for X-ray detection and measurement. Five thin-film samples of (ZnO)x(TeO2)1-x (where x =0.0 wt% (D1), 0.2 wt% (D2), 0.4 wt% (D3), 0.6 wt% (D4), and 1.0 wt% (D5)) were prepared with an aqueous solution of zinc acetate dehydrate and tellurium dioxide precursor on a soda-lime glass substrate using the spray pyrolysis technique. XRD study revealed a polycrystalline structure of the films and showed diffraction peaks belonging to paratellurite TeO2 and wurtzite ZnO in all film samples. A peak shift was observed, indicating the presence of ZnO in the TeO2 crystal lattice. FESEM imagery revealed roughness and the film grain size, which decreased when the concentration of ZnO increased. The optical assessment showed superior transparent behavior in the spectrum of visible light and a minor fall in the optical band-gap value when the concentration of ZnO increased. The I-V characteristic obtained for all the thin-film samples showed a linear increase of current as a function of the applied voltages and X-ray doses ranging from 0.0 to 6.0 V and 50–250 cGy, respectively. The I-V characteristic response of the thin-film samples studied were in the order of D3 >D1 >D2 >D4 >D5. The thin films’ dosimetric sensitivity (minimum measurable dose) values were in the range of 0.610–2.180 mAcm2Gy 1 (0.4590–1.6390 mGy) for D1, 0.370–0.940 mAcm2Gy 1 (1.0640–2.7030 mGy) for D2, 0.610–2.280 mAcm2Gy 1 (0.4390–1.6390 mGy) for D3, 0.00200–0.005280 mAcm2Gy 1 (189.3940–357.1430 mGy) for D4, and 0.00040–0.00150 mAcm2Gy 1 (250.0000–666.6670 mGy) for D1. The R2 value (linearity error) of the I-V plots were in the range of 0.879–0.951 (0.0025–0.0057) for D1, 0.966–0.998 (0.0006–0.0025) for D2, 0.869–0.913 (0.0035–0.0065) for D3, 0.860–0.952 (0.000009–0.00005) for D4, and 0.922–0.978 (0.000002–0.000004) for D5. The ZnO-TeO2 thin-film sensor is therefore a candidate material that can be used for miniaturized radiation measuring devices that can be accommodated in smart devices such as smart watches and smart phones
A comprehensive investigation on the role of PbO in the structural and radiation shielding attribute of P2O5 – CaO – Na2O – K2O – PbO glass system.
(SPRINGER, 2021) Al-Harbi, N., Sayyed, M. I., Kumar, A., Mahmoud, K. A.,; OLARINOYE, OYELEKE; Alhuthali, A. M., & Al-Hadeethi
This study presents the synthesis, physical, structural and gamma-ray shielding characteristics of 40P2O5–20CaO–(30-x)Na2O-10K2O–xPbO (x = 0, 5, 10, 15, 20 mol%) glasses. The glass samples coded as PbCKNP1, PbCKNP2, PbCKNP3, PbCKNP4, and PbCKNP5 were prepared using the melt quench method. Na2O substitution by PbO influenced the molar volume and mass density of the glasses. Structural analysis of the glasses using the X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy confirmed amorphous structure. The photon shielding parameters of the glasses examined via the Monte Carlo simulation code (MCNP-5) revealed that the glasses’ shielding ability improved as PbO content increased. The highest simulated linear attenuation coefficient (LAC) achieved at 0.015 MeV increased from 21.46 to 159.07 cm-1 as the PbO concentration increased from 0 and 20 mol%. The LAC for all fabricated glass samples showed an exponential reduction trend with gamma photon energy. Based on the simulated LAC values, calculated mass attenuation coefficient (MAC), half-value layer (HVL), transmission factor (TF), and radiation shielding capacity (RSC), PbCKNP5 possessed the best gamma-ray protection ability among the investigated glasses.
A protocol for setting dose reference level for medical radiography in Nigeria: A Review
(BAYERO UNIVERSITY, KANO, NIGERIA, 2010-02-10) OLARINOYE, OYELEKE; SHARIFAT I
Patients’ dose audit reports in some Nigerian hospitals had shown large inter- and intra-hospital variations for the same radiological examinations. They have thus presented the need, to have a national standard for radiological diagnostic procedures and set dose limits for individual x-ray examination centers in Nigeria. These will go a long way in reducing inter- and intra-hospital dose range factors, thus reducing doses to as low as reasonably achievable and consistent with clinical objectives of the examinations. In establishing a national dose limit for medical radiological examinations, there is a need to have a national dose survey. This paper suggests a Reasonable and easy procedure for achieving a national radiological dose survey. Due to its simplicity of measurement, the use of entrance surface dose as the dose parameter to be used for setting the dose limit as recommended by the European Union and the International Atomic Energy Agency (IAEA) is also suggested. ESD can be measured directly through the use of solid state detectors, or indirectly by measuring free air exposure which can later be converted to ESD using standard formula. The methods of measuring the entrance surface dose and how to derive the dose limit from them are also highlighted.
An insight into advanced glass systems for radiation shielding applications: A review on different modifiers and heavy metal oxides-based glasses.
(CELL PRESS, 2024) Al-Buriahi, M. S., Kurtulus, R., Eke, C., Alomairy, S.; OLARINOYE, OYELEKE
Ionizing radiation from natural and many synthetic sources is a remarkable tool in many scientific, production, quality control, food preservation, medical, security, and other technological processes. The need to protect humans (public and personnel), gadgets, the environment, and animals from the harmful effects of radiation, while maintaining and expanding the scope of application has made radiation protection an important topic to discuss. Among the methods and materials available for radiation control, shielding and the use of glass shields are the most effective and attractive methods and materials, respectively. In this report, the basic parameters for measuring shielding competences, basic shielding materials and their shortcomings, and glass shields are discussed. Five categories of glasses, namely, borate, germanate, silicate, phosphate, and tellurites, with important shielding attributes, are reviewed. The role of chemical composition, density, and mean atomic number as gamma shielding delineating factors was emphasized. The weaknesses and comparable advantages of each glass system were presented as well. The review concludes by looking at the trend and future of glass shields and research in radiation technology. The data and analysis presented in this review provides scientists and radiation protection technologist on the impact of certain chemical oxides on shielding efficacies of different glass systems.
Annual Effective Dose Estimation due to Gross Alpha and Beta Activities in Nigerian Bottled Drinking Water
(2020) Kolo, M. T.,; OLARINOYE, OYELEKE; SANUSI E; AJAYI M; KADIR A; UMAR S.I; AYEDUN F
Background: Extremely humid, hot and dry climatic conditions of Nigeria has led to an increasing demand for clear and clean portable water supply across the nation. Additionally, the dehydrating traffic situations commonly witnessed in virtually all the major cities in Nigeria has made consumption of bottled water indispensable component of modern life in Nigeria. It is therefore important that the radiological burden incurred by the Nigerian population from ingestion of bottled water be investigated. Materials and Method: Twenty one brands of commercial bottled water regularly consumed in Nigeria were obtained from standard supermarkets and investigated for their gross alpha and gross beta radioactivity. This analysis, as a recommended first step in radio analytical screening, was performed using a gas-free, low background dual phosphor proportional counter. Results: Results of the analysis showed that mean values for gross alpha and gross beta activity concentrations in all the investigated bottled water samples were 15.22±0.93 mBq l-1 and 39.69±1.83 mBq l-1 respectively. These values were below safety limits recommended by the World Health organization. Computed average annual effective dose equivalent for adults, children and infants (lactating age) in Nigeria due to consumption of commercial bottled water were lower than the recommended safeguard of 0.1 mSv for drinking water. Conclusion: The results does not suggest any radiological threat to the health of consumers. However, intermittent monitoring of commercially consumed bottled water is recommended for water quality compliance from radiation safety perspective.
Apatite-wollastonite glass-ceramics containing B2O3 and Na2O: Potential bioactive material for tissue protection during radiation therapy procedures
(ELSEVIER, 2025) Al-Buriahi, M. S.,; OLARINOYE, OYELEKE; İbrahimoğlu, E.
In this study, an attempt to expand available data and functionality of apatite-wollastonite glass ceramics (AW GCs) in medical therapy and bone engineering by estimating and analysing the physical, structural, fast neutron and gamma interaction properties of B2O and Na2O doped AW GCs is presented. The pristine (AW) and (20 wt% B2O3 and 30 wt% Na2O) doped AW GC (AW-B20-N30) samples were prepared using the cold isostatic press method. The samples were subject of structural and physical characterisation through experimental procedures, while their radiation interaction parameters were obtained following standard theoretical models. Samples’ densities were calculated as 2.917 and 2.613 g/cm3, while the Vickers hardness was 553 and 518 HV for AW and AW-B20-N3, respectively. The structure of the samples revealed that Na2O formed the brianite phase inserted in the apatite structure. The mass and linear attenuation coefficients fluctuated within the ranges, 0.0232-13.6853 cm2/g and 0.0676-39.92 cm-1 for AW and 0.021-8.313 cm2/g and 0.055-21.7223 cm-1 for AW-B20-N30, respectively. The half- and tent-value layers increased from about 0.02 to 10.25 cm and 0.06 to 34.05 cm for AW; for AW-B20-N30, the increase is from 0.032 to 12.61 cm and 0.11 to 41.88 cm, respectively. AW was more effective for shielding photons and fast neutrons, and had lower gamma buildup factors compared to AW-B20- N30. The study showed doping AW with B2O and Na2O could be optimised to get equivalent bone material in radiation studies. The AW GCs also showed better shielding effectiveness compared to some traditional shields and could therefore be applied for shielding tissues outside the target volume in radiation therapy
Artisanal Gold Mining Activity in Northcentral Nigeria and Its Implications: Radiological Approach
(2020) GOMINA M; Kolo, M. T.,; OB AWOJOYOGBE; OLARINOYE, OYELEKE
Assessment of Environmental Background Gamma Radiation Variation in Minna Area of Nigeria
(Taylor and Francis, 2024) Adeiza Stephen, A.,; OLARINOYE, OYELEKE; Kolo, M. T.,; Kasim, I.
Radiation has been acknowledged to be responsible for deleterious conditions in living tissues. Hence, environmental background gamma radiation (BGR) measurement is crucial from an environmental and health perspective. In this study, due to the absence of comprehensive background gamma radiation data and the increasing numbers of anthropogenic activities that could increase the BGR level, such as where mining activities are active. The BGR in the Minna area of Niger State, Nigeria, was measured and analyzed in this study. In-situ measurement of the background gamma radiation level was carried out using a well-calibrated portable handheld GQ GMC-500 Plus nuclear radiation detector at an elevation of about 1.0m above ground level. global positioning system from Garmin (GPSmap 78s) was adopted for identifying geographical locations. A total of 1172 points were surveyed across the study area for background environmental radiation. The BGR values ranged from 0.102 to 0.147 lSv/h, with an overall mean value of 0.126 lSv/h. The average measured dose rate was more than twice the reported world average value of 0.059 lSv/h. The annual effective dose equivalent (AEDE) for the research area was calculated to be 0.221 mSv/y on average. The mean AEDE is lower than the ICRP recommended limit. This shows that the population of the Minna area is radiologically safe based on the estimated AEDE value. Similarly, the excess lifetime cancer risk (ELCR) value ranged from 0.626�10 0.774±0.09�10 −3 −3 to 0.901�10 −3 mSv/y with a mean value of mSv/y. The mean value of AEDE is below the 0.24 mSv/y permissible limits as recommended by the International Commission on Radiological Protection (ICRP). The mean ELCR value exceeds the average world value of 0.29�10 −3 . Also, the mean organ dose values estimated for the whole body, liver, kidney, testes, bone marrow, ovaries, and lungs are 0.150±0.02, 0.102±0.01, 0.137±0.02, 0.181±0.02, 0.152±0.02, 0.128±0.02 and 0.141±0.02 mSv/y respectively. The differences in the calculated mean of BGR were attributed to natural and human factors. Geological variation is a fundamental factor that influences the changes in BGR. Human activities, mining, building materials, and the use of phosphate fertilizers in agricultural practices are responsible for the differences in BGR. The ELCR implies that terrestrial gamma radiation does not pose any immediate radiological health effects on residents of the area, but there is a tendency for long-term health hazards in the future, such as cancer, due to the dose accumulated
Assessment of gamma-radiation attenuation characteristics of Bi2O3 – B2O3 – SiO2 – Na2O glasses using Geant4 simulation code.
(SPRINGER, 2021) Sayyed, M. I.,; OLARINOYE, OYELEKE; Elsafi, M.
This work aims to study the radiation shielding properties of Bi2O3–B2O3–SiO2–Na2O glasses (coded as BBS-glasses) using the Geant4 simulation and to determine the effect of the Bi2O3 content on the attenuation capability of the glasses. The mass attenuation coefficient (MAC) of BBS-glasses was estimated by the Monte Carlo simulations in Geant4, and the simulated results were validated by XCOM software. The maximum relative difference between the two approaches throughout the considered gamma-ray energies was 1.05, 1.20, 1.40, 1.52, 1.21, and 1.5%, respectively, for BBS-0–BBS-5, which means that MACestimated through the Geant4 simulation and XCOM are in good agreement; hence, the simulation results are accurate. At each investigated energy, the linear attenuation coefficient value increases with Bi2O3 as a result of the higher molecular weight of Bi2O3, hence higher electron–photon interactions. The effective atomic number varies from 7.65–9.37, 19.64–66.66, 29.01–73.92, 36.54–76.76, 42.72–78.29, and 47.89–79.23 for BBS-0–BBS-5, respectively. The half value layer for the selected glasses followed the trend: (HVL)BBS-5 <(HVL)BBS-4<(HVL)BBS-3 <(HVL)BBS-2 <(HVL)BBS-1 <(HVL)BBS-0. The transmission factor reduces as the thickness of the glasses increases, and the Bi2O3 content in the glasses greatly improved their photon shielding and protection ability. The comparison between the mean free path of the selected glasses with other materials revealed that BBS-5 is a better photon shield than BC and RS-360 commercial glass shields
ASSESSMENT OF NATURAL RADIOACTIVITY LEVELS AND RADIATION HAZARDS IN THE TERTIARY INSTITUTIONS IN MINNA, NIGER STATE, NIGERIA.
(2012-01-15) Kolo, M. T.,; Baba-Kutigi, A. N.,; OLARINOYE, OYELEKE; Sharifat, I.
Activity concentrations of natural radionuclides in 30 surface soil samples collected across the three campuses of the two tertiary institutions in Minna, Niger State, Nigeria, were studied and evaluated. This survey was carried out using gamma spectrometric technique which employs NaI(Tl) gamma detector at the Center for Energy Research and Training (CERT), Ahmadu Bello University, Zaria, Nigeria. The mean values for the activity of 226Ra, 232Th and 40K were found to be 7.8±1.3Bqkg-1, 29.4±0.9Bqkg-1 and 229.4±1.8Bqkg-1 respectively. The activity profile of the primordial radionuclides in the soil samples investigated showed the existence of low level activity across the three campuses. The mean value of the annual effective dose equivalent obtained from this study is 0.04mSvyr-1, with mean external hazard index of 0.2. These average values fall within the internationally provided safety range for outdoor radiation exposure. The values obtained from this investigation for all the radiation parameters for the studied soil samples showed that none of the campuses investigated pose any significant radiological threat to the public.
ASSESSMENT OF NATURAL RADIOACTIVITY LEVELS AND RADIATION HAZARDS IN THE TERTIARY INSTITUTIONS IN MINNA, NIGER STATE, NIGERIA.
(2012) Kolo, M. T.,; Baba-Kutigi, A. N.,; OLARINOYE, OYELEKE; Sharifat, I.
Assessment of shielding potentials and radiological safety indices of Nigerian granite rocks.
(NJTR FUTMINNA, 2019) OLARINOYE, OYELEKE; ALABI AA; SURAJ K
The activity concentration of primordial radioisotopes (238U, 232Th and 40K) in granite rock samples from Minna, North central Nigeria were measured using a sensitive HPGe detector for gamma spectrometric measurement. Five granite rock samples were collected from Maikunkele, Bosso, Maitumbi, Chanchaga and Paiko areas of the town. The average activity concentrations for the radionuclides in the rocks were: 27 ± 4 Bq/kg; 48 ± 7 Bq/kg and 874 ± 86 Bq/kg for 238U, 232Th and 40K respectively. The average absorbed dose rate, effective dose; radium equivalent (Req) and internal hazard index (Hin) were 65 ± 10 nG/h; 0.32 ± 0.05 mSv/y; 140 ± 21 Bq/kg and 0.45 ± 0.07 respectively. All the rock samples had Req less than the recommended safety value of 370 Bq/kg. All evaluated radiological safety indices fell within the recommended safety limits and world average values. The analysis of radionuclide content of the granite rocks showed that they do not pose environmental radiation risk to humans when used as structural shielding materials. Mass attenuation coefficients of the granite samples evaluated via the WinXcom computer code suggested that the granite rocks considered have good shielding capacity comparable to that of ordinary concrete.
B2O3/PbO/Na2O/MgO/Nb2O5 glasses: fabrication, physical, optical characteristics as well as photons/neutrons/beta particles attenuation capacities.
(ELSEVIER, 2022) Alsaif, N. A., Rammah, Y. S.,; OLARINOYE, OYELEKE; Ahmed, E. M., & Abouhaswa, A. S.
Physical, optical characteristics, and radiation attenuation capacities of the prepared (50-x) B2O3 + 30PbO + 10Na2O + 10MgO + xNb2O5 glasses with various doping ratios x = 0, 2, 4, 6, and 8 mol% have been investigated. Glasses were prepared using the well-known melt quenching process and named as their corresponding x value. The density and molar volume of the prepared glasses were increased from 4.71 g/cm3 and 23.76 cm3/mol for the sample with free Nb2O5 to 4.91 g/cm3 and 25.99 cm3/mol for the rich sample with x = 8 mol% of Nb2O5. With increasing Nb2O5 concentration, the broad near-visible band centered was moved towards higher wavelength. The direct band gap energies of glass samples felt from 3.728 to 2.939 eV, while the indirect band gap energies from 3.032 to 1.822 eV as the Nb2O5 substitution ratio increased. Urbach’s energies of the prepared samples were increased with the increasing of Nb2O5. For photons, the maximum values of mass attenuation coefficient (MAC) were 32.67, 33.02, 33.38, 33.74, and 34.10 cm2/g for x = 0 – x = 8, respectively at 0.015 MeV, while the least corresponding MAC value of 0.0286, 0.0288, 0.0291, 0.0293, and 0.0295 cm2/g was obtained at 10 MeV. For neutrons, the fast (MAC)FN was decreased from 0.0185 – 0.0161 cm2/g, while the thermal (MAC)TN was decayed from 6.6538 – 5.5903 cm2/g. Analysis of the TSP and CSDA range of the glasses emphasize the fact that there is no significant difference in the charged particle of the glasses irrespective of the weight fraction of Nb2O5 relative B2O3. Results confirm that the current glasses are superior for radiation shielding materials compared to some commercial concrete and glasses.
Bi2O3 reinforced B2O3 + Sb2O3 + Li2O: composition, physical, linear optical characteristics, and photon attenuation capacity.
(ELSEVIER, 2021) Abouhaswa, A. S.,; OLARINOYE, OYELEKE; Kudrevatykh, N. V., Ahmed, E. M., & Rammah, Y. S.
Role of Bi2O3 on the structure, physical, linear optical characteristics, and radiation protection capacity of antimony borate–lithium with the form (65- x)B2O3 ? 10Sb2O3 ? 25Li2O ? xBi2O3 x = 0 (BSLB0), 4 (BSLB4), 8 (BSLB8), 12 (BSLB12), 16 (BSLB16), 20 (BSLB20) mol% glass systems was examined. The density was increased from 2.7125 to 3.9454 g cm-3 for BSLB0 and BSLB20 glass samples, respectively. The indirect optical bandgap decreases from 2.63 to 2.45 eV, while the direct optical bandgap decreases from 3.06 to 2.89 eV. Therefore, values of the refractive index (n) were varied from 2.50 to 2.56. Both optical (roptical) and electrical (relectrical) conductivities were enhanced with increasing Bi2O3 content in the investigated glasses. The observed trend of linear attenuation coefficient (LAC) values throughout the energy spectrum was followed the sequence: (LAC)BSLB20[(LAC)BSLB16[(LAC)BSLB12[(LAC)BSLB8[(LAC)BSLB4[(LAC)BSLB0 with values in the range of 0.052–14.469, 0.062–28.291, 0.070–42.738, 0.082–61.708, 0.091–79.616, and 0.104–102.154 cm-1 for BSLB0–BSLB20 glasses, respectively. At each energy within the energy spectrum, the mean free path (MFP) and half value layer (HVL) of the BSLB-glasses were decreased in the order of increasing Bi2O3 content in the glasses. The effective atomic number (Zeff) value varies from 6.53 to 15.12, 6.76–16.32, 7.02–17.37, 7.29–18.36, 7.58–19.29, and 7.89–20.16 for BSLB0BSLB20 glasses, respectively. Therefore, BSLB-glasses possess superior photon protection capacity than ordinary (OC) and barite (BC) concretes for photons.
Comparative analysis of NORM concentration in mineral soils and tailings from a tin-mine in Nigeria.
(2020) ATIPO M; OLARINOYE, OYELEKE; OB AWOJOYOGBE
Mining of tin and other related activities have been active and thus leading to economic growth in the Jos area of Nigeria for more than a century. However, mining of minerals has been confirmed to enhance the concentrations of heavy metals and natural radioisotopes in the soil, air and water bodies in the environment. In an attempt to evaluate the radiological burdens resulting from tin mining activities at Rayfield-Du area of Jos, specific activities of naturally occurring radioactive nuclei (238U, 232Th and 40K) concentrations were evaluated in soil samples collected from the mine site. The soil samples were classified as normal soil (S), tailings (T) and mineral soils (M) and their corresponding mean activities for 238U, 232Th and 40K were analysed using an HpGe detector-based gamma spectrometric system. The mean activity concentration for 238U, 232Th and 40K were 323.44, 877.63 and 864.99 Bq/kg, 138.84, 469.31 and 578.65 Bq/kg and 168.83, 436.08 and 346.1 Bq/ kg, respectively for M, T and S samples. The calculated radiation dose parameters for the soil samples were all higher than the recommended safety limit. For all the collected soil samples, the external hazard risk Hext were 2.21, 2.81 and 4.44 for S, T and M, respectively while the mean calculated radium equivalent was 819, 1057 and 1645 Bq/kg for S, T, and M, respectively. The excess lifetime cancer risk estimated for the mine was more than the world average value. The radio-ecological dose rate estimate for non-human biota in the mine revealed that all non-human species except lichen and bryophyte had absorbed dose rate less than the 10 µGy/h screening dose.
Comparative assessment of natural radionuclide content of cement brands used within Nigeria and some countries in the world
(ELSEVIER, 2014) E.O. Agbalagba; R.O.A. Osakwe; OLARINOYE, OYELEKE
The gamma spectrometric analysis of different brands of cement used as building and construction material in Nigeria has been carried out in this study. Samples of 12 brands of gray Ordinary Portland Cement (OPC) and 5 brands of white cement of six samples each were collected and analyzed for their radiological content using gamma spectrometry method. The average value of 226Ra, 232Th, and 40K for OPC is 30.2 ± 10.4 Bq kg−1, 24.6 ± 7.1 Bq kg−1, and 251.3 ± 27.6 Bq kg−1 respectively and the average value for the white cement is 41.9 ± 16.7 Bq kg−1, 30.1 ± 9.4 Bq kg−1 and 340.2 ± 37.7 Bq kg−1 respectively. The total average content of 226Ra, 232Th, and 40K for all the cement brand samples are 36.1 ± 13.6 Bq kg−1, 27.4 ± 8.3 Bq kg−1, and 295.8 ± 32.7 Bq kg−1 respectively. These values obtained are lower when compared to the world average values(226Ra-50 Bq kg−1,232Th-50 Bq kg−1and40K-500 Bq kg−1)forbuildingmaterials.Theestimatedradium equivalent activities (Raeq), representative index (Iγ), average absorbed γ-dose rate (D), the annual effective dose rate (AEDE), annual gonadal dose equivalent (AGDE) external and internal hazard indices and the Excess life cancerrisk (ELCR)werelowerthantherecommendedsafelimitandarecomparablewithresultsfromsimilar studies conducted in othercountries. The evaluated mean gonadal dose equivalents of three cement brandsam ples were found to be higher than the world average for building material while others are less than the world average. A comparison of the average activity values obtained in Nigeria cement and other countries of the world show that those countries with history of high radionuclide solid minerals have activity concentration far above that of Nigerian cement, while these values agreed with those obtained in other countries.
Comparison of radiation shielding and elastic properties of germinate tellurite glasses with the addition of Ga2O3.
(ELSEVIER, 2022) Alfryyan, N., Alrowaili, Z. A., Somaily, H. H.,; OLARINOYE, OYELEKE; Alwadai, N., Mutuwong, C., & Al-Buriahi, M. S.
Thecurrent researchelucidatesthenuclearshieldingcapacityofgerminatetelluriteglasses: 41.7GeO2–41.7TeO2–16.6Ga2O3,37.5GeO2–62.5TeO2,10.4GeO2–72.9TeO2–16.7Ga2O3and12.5 GeO–87.5TeO2. Gamma-ray photon, fast neutron and electron shielding parameters of the present glassy materials were evaluated and studied via the Geant4Monte Carlo, Phy-X/PSD software, ESTAR and analytic computations. In addition, Makishima–Mackenzie’s theory was applied to assess the elastic properties of the studied tellurite glass systemcontainingGa2O3 and/or GeO2. The effective atomic number of the glasses varies from19.14to44.08for41.7GeO2–41.7TeO2–16.6Ga2O3,20.63–48.02for37.5GeO2–62.5TeO2, 21.15–48.15 for 10.4GeO2–72.9TeO2–16.7Ga2O3 and 22.42–50.29 for 12.5GeO2–87.5TeO2. The obtained fast neutron removal cross sections of the glasses were 0.0991, 0.0966, 0.1024and0.1021cm−1,respectively,for41.7GeO2–41.7TeO2–16.6Ga2O3,37.5GeO2–62.5TeO2, 10.4GeO2–72.9TeO2–16.7Ga2O3 and 12.5GeO2–87.5TeO2. Also, an equilibrium is reached between total stoppingpower (TSP)due to radiation and collision for electron sate nergy =1.0MeVwherethe TSPwasminimumin theinvestigated glasses. Computed Young’s modulus for37.5GeO2–62.5TeO2wasthelowestwithavalueof0.218GPawhiletheother three glasssampleshavealmostequalvalueof0.226GPa.Thepresentglasses’shieldingabilityout classedsomeconventionalshields,hencehavepotentialforradiationsafety/shieldingpurposes innuclearfacilities
Crystal structure refinement of co-doped Ba0.88Ca0.12Ti0.975Sn0.025O3 ceramic
(2017) Umaru Ahmadu; OLARINOYE, OYELEKE; Moses Agida; Auwal M. Muhammad
Ba/Ca-doped barium titanate has been prepared by solid state reaction to produce Ba0.88Ca0.12 Ti0.975Sn0.025O3(BCST) ceramics. Five samples were irradiated using neutron fluence of 8.1 106, 9.72 107, 8.75 108, 6.99 109 and 1.4 1010 n/cm2 (BCST-06 to-10). The structure and phase compositions of the control (BCST) and irradiated samples were determined by X-ray diffraction and indicate the presence of a majorly single phase tetragonal barium titanate (S.G.P4mm) with a minor phase CaTiO3 (orthorhombic). However, Rietveld refinement using GSAS II suite of programs indicates a tetragonality ratio (c/a ¼ 0.996) which is pseudocubic with a reduction in volume of 0.03% in the control compared to pristine BT. The irradiated samples exhibited changes in tetragonality (maximum of 0.82%) and variation in volume (0.58%, maximum) over the range of fluence investigated. A complete vacancy was observed in the Ca site of BCST10 but not in the oxygen sites while the occupancies of other metal sites varied. The substitution of Sn is expected to lead to a lower transition temperature and an increase in dielectric constant near the transition temperature of the control. While the changes in volume, tetragonality and occupancy of the irradiated samples are expected to affect their electromechanical properties due to changes in the Ti octahedra which would lead to a slight degradation in device performance.
Dense and environment friendly bismuth barium telluroborate glasses for nuclear protection applications.
(ELSEVIER, 2021) Al-Buriahi, M. S.,; OLARINOYE, OYELEKE; Alomairy, S., Kebaili, I., Kaya, R., Arslan, H., & Tonguc, B. T.
In this paper, four samples of bismuth barium telluroborate glasses in the chemical composition of 20Bi2O3 + 30BaO +xEr2O3 +(30 – x)B2O3 +20TeO2, here x is between 0.05 and 2 mol%) coded as BTBE1, BTBE2, BTBE3, and BTBE4 are reported for potential use in nuclear shielding applications. Geant4 simulations were well designed to obtain the mass attenuation coefficient, μ/ρ for the BTBE1 – BTBE4 specimens at 356 keV–2.51 MeV photon energies. Then, the obtained results are confirmed by using WinXCOM platform. The μ/ρ values were used to assess the nuclear shielding capacity of BTBE1 – BTBE4 specimens in terms of effective atomic number, Zeff, mean free path, MFP, and half-value layer, HVL. Additionally, the buildup factors of BTBE1 – BTBE4 specimens were computed via G-P fitting method at 0.015–15 MeV photon energies and up to 40 mfp (penetration depths). Also, the neutron shielding capacity of the glasses was assessed by calculating the removal cross sections (∑ R). Our results indicate that there is a remarkable enhancement in the gamma shielding features by adding Er2O3 content in the BTBE1 – BTBE4 specimens. It is found that BTBE4 and BTBE3 glass specimens have high shielding quality against nuclear radiation. Gamma-rays and fast neutrons shielding parameters of the BTBE1 – BTBE4 specimens are compared with several commercial and traditional shielding materials. These comparisons concluded that the reported glasses are quite useful for radiation protection purposes.
Determination of structural features of different Perovskite ceramics and investigation of ionizing radiation shielding properties.
(ELSEVIER, 2021) Slimani, Y., Hamad, M. K.,; OLARINOYE, OYELEKE; Alajerami, Y. S., Sayyed, M. I., Almessiere, M. A., & Mhareb, M. H. A.