Physics
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Item A protocol for setting dose reference level for medical radiography in Nigeria: A Review(BAYERO UNIVERSITY, KANO, NIGERIA, 2010-02-10) OLARINOYE, OYELEKE; SHARIFAT IPatients’ 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.Item A review of coating tin oxide electron transport layer for optimizing the performance of perovskite solar cells(Chemistry of Inorganic Materials Volume 6, August 2025, 100100, 2025-04-10) YUSUF Abubakar Sadiq; Ahmad Alhaji Abubakar; Isah Kimpa Mohammed; Umaru Ahmadu; Kasim Uthman IsahPerovskite solar cells (PSCs) have recently emerged as a transformative technology in the photovoltaic sector, drawing considerable attention due to their rapid advancements in power conversion efficiency (PCE), which now exceeds 26.7 %. This efficiency level places them in direct competition with conventional silicon-based solar cells. A key element in ensuring the high performance of PSCs is the charge transport layer (CTL), particularly the electron transport layer (ETL). The ETL plays a crucial role by efficiently collecting photo-generated electrons from the perovskite layer and transferring them to the transparent conductive oxide electrode. Among the ma- terials used for ETLs, tin oxide (SnO 2) stands out for its wide band gap, excellent optical transparency, superior carrier mobility, and remarkable chemical stability. Additionally, SnO2 can be deposited at low temperatures, making it ideal for mass production and adaptable for applications such as flexible devices. Despite its inherent advantages, the overall performance and quality of the ETL, and thus the device itself, are heavily influenced by the fabrication process. This study reviews recent approaches to fabricating SnO 2 ETLs in PSCs, with a focus on optimizing efficiency and long-term stabilityItem 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 FBackground: 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.Item Artisanal Gold Mining Activity in Northcentral Nigeria and Its Implications: Radiological Approach(2020) GOMINA M; Kolo, M. T.,; OB AWOJOYOGBE; OLARINOYE, OYELEKEItem ATTAINMENT OF THE 7-POINT AGENDA IN NIGERIA THROUGH SCIENCE AND TECHNOLOGY(The Nigerian Journal of Research and Production, 2010-04) Eze, C. N.The 7-point agenda of the Nigerian President, Musa Umaru Yar’adua is a suitable road map to the quick modernization and industrialization of Nigeria. The agenda touches on the most important aspects of the needs of the people of this country. For instance, adequate supply of power and energy, the effective modernization of education at all levels from primary to tertiary, the beefing up of the system of transportation throughout the country, the departure from the dependence on crude oil to new areas of employment and wealth creation such as in agriculture and solid minerals and the assurance of security especially in Niger Delta zone of the country – all these will give this country a new lease of life never experienced before. This paper, therefore, contains analysis of the bone of contention of the -point agenda as enumerated by the president himself. Namely, power and energy, food security, wealth creation, transportation, land reform, education and security as epitomized in the Niger Delta situation. The purpose of this paper is to critically examine the issues involved in achieving the agenda, or otherwise, show the strengths and weaknesses of the various proposals, in relationship with the existing science and technology in this country at the moment, and finally draw conclusion and make recommendations. The science and technology available in this country has already produced very formidable manpower that can handle Nigeria’s current state of development. If, however, there are certain rare areas where suitable technology is not available, the country is rich enough to pay for technology transfer from outside. The re-branding of Nigeria now in progress, though not part of the 7-point agenda, has created excellent opportunities for smoothening the rough edges of the agenda and, hopefully, will act as icing sugar and finishing touches to it. Keywords: Science and technology, the 7-point agenda, development, Nigerian government and the masses.Item Bound state solutions of the generalized shifted Hulthén potential(Indian Journal of Physics Publishing model Hybrid, 2020-01-09) YUSUF Abubakar Sadiq; C. O. Edet; P. O. Okoi; P. O. Ushie; P. O. AmadiIn this study, we obtain an approximate solution of the Schrödinger equation in arbitrary dimensions for the generalized shifted Hulthén potential model within the framework of the Nikiforov–Uvarov method. The bound state energy eigenvalues were computed, and the corresponding eigenfunction was also obtained. It is found that the numerical eigenvalues were in good agreement for all three approximations scheme used. Special cases were considered when the potential parameters were altered, resulting in Hulthén potential and Woods–Saxon Potential, respectively. Their energy eigenvalues expressions agreed with the already existing literature. A straightforward extension to the s-wave case for Hulthén potential and Woods–Saxon potential cases is also presented.Item Chemically Deposited Doped Titanate Ternary Metal Oxide Thin Films Via Spray Pyrolysis Route-Preparation, Characterization and Solar Cell Application Analysis(4th Africa Nano Conference and Workshop, 2021-07) Eze, C. N.; Onyia, A. I; Nnabuchi, A. ISpray pyrolysis method of deposition is a simple, cheap, low cost and conventional method that gives uniform deposition. With this motivation, a simple approach of spraying ZnTiO3 nanoparticles on a substrate is reported. The approach occurs with ternary metal oxide and is environmentally friendly. This follows the quest to further improve the physical and chemical properties of ternary metal oxide which has become noticeable in recent times. The crystallization temperature of ZnTiO3 was 2000C. Among other investigations the SEM result shows a perovskite structure-like morphology. Further characterization performed on the thin film for the structural aspect which gives XRD of the thin film shown on the diffractogram is in agreement with the standard diffraction of ZnTiO3 which is identified as tetragonal structure. UV-Vis absorption spectroscopy was also used to characterize the final product and the spectra indicated that the absorbance obviously increased in the visible light region with absorption peak at about 209 nm and with optical band gap which infers that it has potential application in solar energy devices.Item Determination of the Radiological Risk Associated with Naturally Occurring Radioactive Materials (NORM) at Selected Quarry Sites in Abuja FCT, Nigeria: Using Gamma-Ray Spectroscopy(2015) H. O. Shittu1,; OLARINOYE, OYELEKE; A. N. Baba-Kutigi; S. F. OlukotunThe concentrations of natural radionuclides (238U, 232Th and 40K) in the granite rocks of major quarry sites in Federal Capital Territory, (FCT), Abuja was determined by gamma ray spectroscopy using a well calibrated NaI (Tl) detector system. The range of activity concentrations of (238U, 232Th and 40K) were found to be (37.41 ± 5.41 to 110.16 ± 7.50, 64.13 ± 15.99 to 349.11 ± 69.44 and 323.99 ± 3.73 to 2727.95 ± 14.69) Bq.kg-1 respectively. The total average of 238U, 232Th and 40K were found to be 74.74 ± 5.67. 199.23 ± 43.30 and 1021.27 ± 7.14 Bq.kg-1 respectively, which are high when compared with worldwide average of 33, 45 and 412. The high value is attributed to geology of the areas where the granites is mined and varies from different quarry sites. The radium equivalent activity concentration was found in the range from 331.50 to 529.91 Bqkg-1, the absorbed dose rate was found to be in the range from 148.72 ± 30.69 to 243.78 ± 30.49 nGyh-1 with an average value of 197.45±29.06 nGyh-1, and the outdoor annual effective dose equivalent (AEDE) was found to vary from 0.13 to 0.38 mSvy-1, which is below the safety limit of 1 mSv.y-1 as recommended by International Commission on Radiological Protection [19]. Also, the internal and external hazard indices were found to be more than unity, suggesting that workers and people living in such site could be exposed to radiological hazard.Item Effect of Ag2O/V2O5substitution ontheradiation shielding ability of tellurite glass system via XCOM approachand and FLUKAsimulationS(SPRINGER, 2021) OLARINOYE, OYELEKE; Alomairy, S., Sriwunkum, C., & Al-Buriahi, M. S.ThisstudyfocusesontheeffectofAg2O/V2O5substitutionontheradiationshieldingabilityoftellurite glass systemwiththechemicalcompositionofxAg2O+40TeO2+(60−x)V2O5with0<x< 50mol%.FLUKAcodewassuccessfullyemployedforsimulationtheradiationinteractionparameters of theglass systems.Theresultsofthesimulationswerecomparablewiththepredicationsoftheory. Thereafter, several empirical equationswereusedtostudytheshieldingabilityoftheglasssystemsagainst neutronsandchargedparticles.Theresultsindicatethatlinearattenuationcoefficientchangeswithenergy andreachesmaximumat0.6MeV(minimumat10MeV)withthevaluesof0.2806(0.109),0.3181(0.121), 0.3771(0.1498),0.409(0.168),0.4588(0.1911),and0.5162(0.2180)forx=0,10,20,30,40,and50mol%, respectively. Beyond5MeV,thegammarayconstantwasfoundintheorderof G = x 50 ( ) > G = x 40 ( ) > G = x 30 ( ) > G = x 20 ( ) > G = x 10 ( ) > G = . x 0 ( ) Forallthechargedparticles,theprojectilerangewasnotedin the orderof(R)x=0>(R)x=10>(R)x=20>(R)x=30>(R)x=40>(R)x=50.Finally,weprovidean extensive comparativestudybetweenAVT-glasssystemsandstandardtraditionalmaterials.Theobtained resultssuggestthesampleofx=50mol%asthebestphoton,fastneutronandchargedparticleshield amongstthepresentglasssystems.Hence,AVT6couldbeusedinradiationsafetyapplicationsasashieldItem Effect of Al Dope with ZnO Electron Transport Layer in Perovskite Solar Cells Using SCAPs 1-D Simulation(Nigerian Journal of Physics (NJP)ISSN online: 3027-0936ISSN print: 1595-0611, 2024-06-01) YUSUF Abubakar Sadiq; Ramalan, A. M; Abubakar, A. A; Mohammed,I.K; Ibrahim, S. O; Adamu, F. E; Ahmadu, U; Isah, K. UPerovskite solar cells have shown exceptional performance and significant advancements in solar cell efficiency. For perovskite solar cells to conduct electrons and generate current, one of the key components is the substance known as the electron transport layer (ETL). Using the SCAPS 1D modelling program, ZnO: Al was used in this instance as the ETL material in a perovskite solar cell. Because of its interaction with the perovskite material, the ZnO: Al ETL demonstrated high cell efficiency. The performance of the ZnO: Al-doped-based solar cell achieved a PCE as high as 23.5%. In the meanwhile, the greatest cell performance in terms of enhancing the charge transport mechanism and raising cell efficiency was shown by perovskite solar cells doping the ETL with Al and having the right layer thickness. Thus, throughout the manufacturing process, the parameters used in this study may serve as a guide.Item EFFECT OF ELECTRON TRANSPORT LAYERS, INTERFACE DEFECT DENSITY AND WORKING TEMPERATURE ON PEROVSKITE SOLAR CELLS USING SCAPS 1-D SOFTWARE(EAST EUROPEAN JOURNAL OF PHYSICS. 1. 332-341 (2024), 2023-12-30) YUSUF Abubakar Sadiq; A.M. Ramalan; A.A. Abubakar; I.K. MohammedPerovskite solar cells have garnered significant attention from solar cell researchers due to their potential for achieving high efficiency, primarily attributed to their exceptional Electron Transport layer (ETL). One of the key elements of perovskite solar cells for transporting electrons to generate current is the ETL material. Moreover, there is a promising avenue for enhancing stability and reducing fabrication costs by substituting the transport layer. In this study, TiO2 and SnO2 were used as ETL materials in the architecture of perovskite solar cells for a comparative analysis between two devices featuring distinct structures: TiO2/CH3NH3PbI 3 /Spiro- OMeTAD and SnO 2/CH3NH3PbI 3/Spiro-OMeTAD. To evaluate the performance of each electron transport layer (ETL), the SCAPS 1D tool was employed. The investigation involved varying the thickness of the electron transport layers, interface defect density and working temperature, allowing for a comprehensive assessment of key parameters such as voltage at open circuit (Voc), short circuit current density (Jsc), fill factor (FF), and overall efficiency (PCE%). Remarkably, when employing SnO2 as the ETL, the achieved efficiency stands at 10.10 %. In contrast, utilizing TiO2 as the ETL yields a slightly higher efficiency of 12.84%. These findings underline the nuanced influence of transport layer materials on the overall performance of perovskite solar cellsItem Effect of Sb2O3 addition on radiation attenuation properties of tellurite glasses containing V2O5 and Nb2O5(2021) Al-Buriahi, M. S.; Hegazy, H. H.; Alresheedi, F.; Somaily, H. H.; Sriwunkum, C.;; OLARINOYE, OYELEKEIn the present work, we have studied the effect of Sb2O3 addition on gamma, neutron, and charged particles attenuation properties of tellurite glasses in the chemical structure of 84TeO2 + xSb2O3 + 1V2O5 + (15-x)Nb2O5, where x is between 0 and 15 mol% with step of 5. Monte Carlo simulations (by using FLUKA code) were employed to investigate the gamma attenuation parameters for photon energies of 0.6, 1.25, 1.5, 2, 3, 5, and 10 meV. For every photon energy, the results of FLUKA simulations were theoretically approved using the XCOM approach. The obtained results show that the Sb2O3 addition increased the mass attenuation coefficient (µ/ρ) ranges from 0.03318 to 0.08003, 0.03334–0.08021, 0.03349–0.08038, and 0.03363–0.08054 cm2 g−1 for TSVN1, TSVN2, TSVN3, and TSVN4, respectively. For the studied glasses, the maximum (minimum) effective atomic number (Zeff) was obtained at 10 meV (1.25 meV) with corresponding values of 28.85 (21.58), 29.80 (22.27), 30.77 (23.00), and 31.78 (23.77). The exposure rate (ER) follows the trend: (ER)TSVN4 > (ER)TSVN3 > (ER )TSVN2 > (ER)TSVN1. Different effects of Sb2O3 addition were observed on the shielding properties for the thermal and fast neutrons. Finally, the influences of Sb2O3 addition on the attenuation features of the studied glasses were discussed in detail for charged particles such as protons, alpha particles, and electrons. It is concluded that the investigated glass specimens can be utilized for various nuclear applications as non-toxic shields against the radiation of gamma, neutron, and charged particles.Item Effects of TeO2 and B2O3 on photon, neutron, and charged particle transmission properties of Bi2O3-BaO-LiF glass system.(SPRINGER, 2021) OLARINOYE, OYELEKE; Alomairy, S., Sriwunkum, C., Hegazy, H. H., & Al-Buriahi, M. S.This work investigates the effects of TeO2 and B2O3 on photon, neutron, and charged particle transmission properties of Bi2O3BaO-LiF glass system. Photon transmission parameters were obtained via narrow beam setup simulation via FLUKA and those obtained from experimentally proved XCOM calculations. The attenuation factors of μ=ρ IS and μ=ρ PP control the value of μ=ρ at energies greater than 1.5 MeV; however, the region of influence differs for both absorption processes. While μ=ρ IS peaks occur at 3 MeV, the influence of μ=ρ PP becomes appreciable at E > 5 MeV. The values of linear attenuation factor (μ) ranged from 0.2119–0.5283, 0.2085–0.5248, 0.1837–0.4676, 0.1639–0.4223, 0.1519–0.3971, 0.1370–0.3638, and 0.1222–0.3315 cm-1 as B2O3 increased from 0 to 60 mol % with step of 10, respectively. The spectra of projected range (R) of the ions and CSDA range of electrons show that the TSP of electrons in the glasses increases as B2O3 increased from 0 to 60 mol % for energy lower than 5 MeV; however, it reverses at 10 MeV. The ability of the present glass system for stopping the transmission of various radiation beams reveals its potential use for shielding applications in medical and nuclear facilities.Item ESTIMATION OF PATIENTS’ ORGAN DOSES AND CONCEPTUS DOSES FROM SELECTED X-RAY EXAMINATIONS IN TWO NIGERIA X-RAY CENTRES(OXFORD, 2009-01-06) OLARINOYE, OYELEKE; OGUNDARE F,O,Nigeria X-ray centres, Niger State General Hospital (NGH) and Two-Tees (TTX), are reported. Air kerma was measured, and entrance surface dose (ESD) and half-value layer estimated for each set of tube potential (kVp), focus to skin distance and current–time product (mAs) used for each of the patients included in this study. Results show that the mean air kerma in the two centres are similar for the three projections considered in this study. Organ doses ranged from <0.01 to 2.18 mGy in NGH and from <0.01 to 1.29 mGy in TTX for examinations of the abdomen, from <0.01 to 0.20 mGy in NGH and from <0.01 to 0.13 mGy in TTX for examinations of the skull and from <0.01 to 3.90 mGy in NGH and from <0.01 to 1.96 mGy in TTX for examinations of the chest. Generally, no significant difference is seen between the organ doses of male and female patients. In NGH, organ doses are generally greater than those from TTX for the three examinations. The mean ESDs for examinations of the chest postero-anterior, abdomen antero-posterior (AP) and skull AP are, respectively, 5.37, 6.28 and 4.24 mGy in NGH, and 5.82, 5.33 and 4.76 mGy in TTX. The ESDs reported in this study, except for examinations of the chest, are generally lower than comparable values published in the literature. Conceptus doses were also estimated for female patients using normalised published conceptus dose data for abdomen examinations. The estimated conceptus doses were >1 mGyeven when the conceptus was located 12 cm below the surface of the abdomen.Item Estimation of the Calorific Value and Electrical Energy Potential of Waste Generated Biomass Within Abakaliki Meteropolis Ebonyi State, Nigeria(American Journal of Nano Research and Applications, 2020) Igbo, M. E; Chikeleze, P. C; Onyia, A.I; Igbo, N. E; Eze, C. N.; Chima, A.IAbstract: This study was conducted to determine the electrical energy potential of municipal solid waste (MSW) generated biomass within Abakaliki metropolis, Ebonyi State, Nigeria. The MSW samples were collected at two different points from each of the waste management zones, with each zone covering at least twelve (12) streets. It was then sorted into three major categories according to their constituents viz; metals, plastics and biomass. In this study, the biomass component of the MSW sample was is our focus. Thus, the biomass sample was sun dried and then ground into powdered form. It was thoroughly mixed, shredded, sieved and subsequently analysed at the Lorcin Technologies Port Harcourt, Nigeria. Currently, an average of 360 tons of MSW is generated within Abakaliki metropolis on daily bases. This translates to an electrical energy potential of approximately 320MW. The MSW-generated biomass analysis estimates the Gross Calorific Value (GCV) or Higher Heating Values (HHV) to be 11.644MJ/kg. This value which practically determines the electrical energy of the waste sample is highly suitable for many thermal conversion processe. This translate to the fact 0.925kg of biomass will generate electrical power of 1KWh. Hence, one unit of electricity=10765KJ/Kg/GVC (KJ/Kg).Item Evaluation of radiation shielding capacity of vanadium–tellurite–antimonite semiconducting glasses(ELSEVIER, 2021) Rammah, Y. S.,; OLARINOYE, OYELEKE; El-Agawany, F. I., Mahmoud, K. A., Akkurt, I., & Yousef, E.Effects of antimony trioxide (Sb2O3) on the shielding features of ternary tellurite-vanadium- antimonite glasses were investigated. The glasses chemical composition are described by 40TeO2-(60-x) V2O5-xSb2O3: 0 ≤xSb2O3 ≤10 mol%. The mass attenuation coefficients (MAC) were simulated using Monte Carlo simulation code (MCNP- 5) and estimated theoretically via WinXcom program for 15 keV up to 15 MeV photon energy. Alpha and proton stopping power and projected range were computed utilizing the SRIM program. Furthermore, other effective shielding parameters like linear attenuation coefficient (LAC), desired shield thickness, and effective atomic number were calculated relying on the estimated MAC values. The photon’s accumulation within the studied glasses in terms of buildup factors has been estimated via the EXABCal program. The MAC shielding capacity’s output findings revealed an increment from 28.9 to 31.3 cm2/g with increasing the Sb2O3 ratio from 0 to 10 mol %, respectively. The glass samples coded TVS0 recorded the largest (ΣR) among all studied samples. Results concluded that raising the Sb2O3 insertion ratio is significantly enhances the TVS shielding capacity. Thus, the investigated glass samples are good candidates for several nuclear protection applications.Item Evaluation of radioactivity concentration of some selected mineral rocks from Mayo-Belwa Local Government Area of Adamawa State, Nigeria.(DUJOPAS, 2022) Oduh, I. O., Joseph, S. R.,; OLARINOYE, OYELEKE; Kolo, M. T.,Radiation from natural sources is constantly present around people and their surroundings. Natural Occurring Radioactive Materials (NORM) present in rock, soil and underground water are the major sources of this radiation. In this study, radioactivity concentration of 238U, 232Th, and 40K from Ten (10) different Granite (GN), Gneiss (GS), and Migmatite (MG) rocks samples obtained from Mayo Belwa Local Government Area of Adamawa State were evaluated using a well calibrated and shielded Canberra 3 x 3 inch NaI(Tl) detector at the National Institute of Radiation Protection and Research (NIRPR), University of Ibadan. Rock samples were cleaned, pulverised and placed in the detector for counting, and based on standard expressions, the radionuclide content of the granite rock samples were evaluated. The result shows that the activity concentration of 238U, 232Th, and 40K in GN samples varies from 62.44 – 117.67 Bq/kg, 76.59 – 165.58 Bq/kg, and 688.03 – 1472.42 Bq/kg with corresponding mean of 74.59 ± 3.12, 104.41 ± 3.12, and 950.16 ± 3.12 Bq/kg. Activity concentration of 238U, 232Th, and 40K in GS samples ranges from 19.23 – 36.49 Bq/kg, 29.06 – 49.42 Bq/kg, and 310 – 924.21 Bq/kg with corresponding mean of 28.1 ± 5.36Bq/kg, 38.92 ± 6.38 Bq/kg, and 664.21 ±178.14 Bq/kg. Activity concentration of 238U, 232Th, and 40K in MG samples ranges from 32.11 – 74.73 Bq/kg, 40.79 – 105.87 Bq/kg, and 453.34 – 1040.77 Bq/kg with corresponding mean of 50.19 ± 14.35 Bq/kg, 60.50 ± 19.96 Bq/kg, and 714.88 ± 200.37 Bq/kg. The mean activity from this study are higher than the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) global mean of 238U (32 Bq/kg), 232Th (45 Bq/kg), and 40K (420 Bq/kg) in soil and rock samples except for 238U and 232Th in GS samples which are lower than the recommended standards. The results signifies that usage of such rocks as building construction raw materials might pose radiological hazards in the long run. Therefore, mineral content of the rock responsible for the high radionuclide concentration should be investigated.Item High Terrestrial Radiation Level in an Active Tin-Mine at Jos South, Nigeria(2020) ATIPO M; OLARINOYE, OYELEKE; OB AWOJOYOGBE; Kolo, M. T.,Mineral mining and milling can be a source of national economic and technological development. However, mining of minerals has been confirmed to disturb the natural distribution of radioisotopes in the soil, air and water bodies in the biota. In an attempt to evaluate the radiological burden resulting from tin mining activities at Rayfield-Du area of Jos, the background gamma-radiation level in the mine was measured via a well calibrated hand-held dosimeter placed at 1 m above ground level. The mean absorbed dose rate, annual effective dose rate and excess lifetime cancer risk for the mine was 0.83 µSvh-1; 1.44 mSv-1 and 0.005 respectively. Generally, dose rates were higher in the mine pits and processing areas as compared to administrative areas of the mine. The mean measured dose rate and calculated dose parameters for the mine were all high when compared to the regulatory limit for public exposure. The potential of developing radiation-induced health defects as a result of high radiation absorbed dose rate by the miners and dwellers around the mine is highly probable.Item Improving the stoichiometry of RF-sputtered amorphous aluminathin films by thermal annealing(2015) OLARINOYE, OYELEKE; F.O. OGUNDAREHigh quality alumina thin films weredeposited on glass substrate by reactive radio-frequency sputtering. The de position process and rate were controlled by radio-frequency power and reactive gas (oxygen) flow rate. The re lationships between O/Al ratio contents and the structural, electrical resistivity and optical parameters of the films were investigated. The O/Al of the films varied with change in oxygen flow ratio, power density and post deposition annealing. The structure and phase of the filmswere unaltered as the deposition parameters and post depositionannealing up to 573 Kwerevaried. O/Al of 1.5 was obtained at oxygen flow ratio of 11%, radio-frequency power of 250 W and post deposition annealing of 573 K. The sheet resistance of the films were all very high but the same within experimental uncertainties. The optical parameters (transmittance, refractive index and extinction coefficient) of the films varied considerably and dependedonthe films’ stoichiometryItem Investigation of mechanical properties, photons, neutrons, and charged particles shielding characteristics of Bi2O3/B2O3/SiO2 glasses.(SPRINGER, 2021) OLARINOYE, OYELEKE; El-Agawany, F. I., Gamal, A., & Rammah, Y. SMechanical properties, uncharged and charged particles shielding capacity of 60Bi2O3-(40-x) B2O3-xSiO2: x = 0 (S1), 10 (S2), 20 (S3), 30 (S4), and 40 (S5) mol% glasses have been investigated. The enhancement in Young’s, shear, and longitudinal elastic moduli and Poisson’s ratio of the denser Bi content of the S-glasses was confirmed via bond compression (B–C) and Makishima–Mackenzie (M–M) models. The trend order of the mass attenuation coefficient (MAC) is consistent with that of the mass density as (S1)MAC < (S2)MAC < (S3)MAC < (S4)MAC < (S5)MAC. The highest value of the linear attenuation coefficients (LAC) for each of the S-glasses was obtained at photon energy of 15 keV with values of 601, 624, 640, 648, and 661 cm−1 for S1–S5, respectively. The increasing trend of the mean free path (MFP) is opposite to that of MAC and LAC with the order: (S1)MFP > (S2)MFP > (S3)MFP > (S4)MFP > (S5)MFP. The maximum tenth value thickness (TVT) of the glasses was recorded at 4 MeV with values of 3.93, 3.79, 3.70, 3.67, and 3.60 cm for S1, S2, S3, S4, and S5, respectively. The trend of the effective atomic number (Zeff) directly follows the MAC. Both exposure and energy absorption buildup factors EBUF and EABUF) were increased with photon energy and depth of penetration except at Bi absorption edges where spikes were seen. Comparing the effective linear attenuation coefficient (ELAC) of the glasses, it is affirmed that S5 has the greatest photon absorption coefficient for all the considered energy and depth. Therefore, the S-glasses are better photon absorber and will perform better in gamma radiation shielding in nuclear facilities compared to commercially available glass shields (RS360 and RS520) and a recently investigated glass matrix (TVM60). In addition, the glass system can thus be used for fast neutron absorber rather than ordinary concrete or water.