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- ItemANALYSIS OF THE IMPACT OF CATTLE RUSTLING ON RURAL LIVELIHOOD IN ZAMFARA STATE, NIGERIA(2021-12)Cattle rustling has become a problem of major concerned in northern region of Nigeria with quite alarming casualty figures in Zamfara State. The government of Zamfara State reported that nearly 500 villages and 13,000 hectares of land were devastated and 2,835 people killed between 2011 and 2018. Despite this unsettling scenario the impact of cattle rustling on specific rural livelihood options is markedly unclear which calls for this study. This study aimed at analyzing the impact of cattle rustling on rural livelihood in Zamfara State. A total of 390 copies of questionnaire were administered to the respondents using multi-stage sampling. Data was analyzed using descriptive statistics such as frequency count, percentages and mean scores. Also, inferential statistics such as Relative Importance Index (RII), and Z-test were used to examine the consequences of cattle rustling and the extent of cattle rustling effect on rural livelihood. The study reveals that cattle rustling occurred on a monthly basis (55.7%) rustling occur mostly in the midnight and usually last for more than two hours (37.5%). As claimed 38.5% of respondents by the estimated number of cattle rustling between 2014 - 2020 exceeded 50 persons. It was found that about 57% of the respondents reported that farming activities are affected by cattle rustling followed by 24% who reported that cattle rearing was affected. It was ascertained that there is significant difference between all the variables observed before and during cattle rustling at P-value of less than 0.05. The most adopted cattle rustling management strategies are reporting of suspected of cattle rustler is to the village head and people run to safer places for refuge during cattle rustling attack with mean scores of 4.10 and 3.90 respectively. The study recommends that there should be effective deployment of security personnel to the affected community to intensify the security of the affected communities. There should be regular surveillance around the affected communities, which will enable a track of the location of the rustlers.
- ItemGEOLOGY, STRATIGRAPHY AND INORGANIC PETROLEUM GEOCHEMISTRY OF THE BORNU BASIN AT ITS BOUNDARY WITH UPPER BENUE TROUGH, NE NIGERIA(2021-12)The study area is situated in the southwest part of the Nigerian sector of the Bornu Basin, which falls between latitudes 10o 52I 30II to 11o 15I N and longitudes 11o 37II 30II to 12o E. A detailed geological mapping coupled with sample collection was carried out within the study area so to analyze the samples. Geological map was produced distinguishing different lithological units on the basis of their field relationships using various geological parameters. Petroleum geochemical analytical methods were employed using AAS and MREAS to determine source rocks maturation level of some selected shale samples for trace elements and transition metals that are usually incorporated into the petroleum charge system. A new proposed stratigraphy from the Chad (Bornu) Basin is here in presented to give a detail and comprehensive outlook of the study area, which in turn reflects a true image of the entire basin. For the first time, the basin is being classified into group and members in order to revise and correct the stratigraphy on the basis of anomalies observed by this work and previous researchers. The oldest unit in the basin Bima Formation is now regarded as a group in the Bornu Basin because of some new field evidences that were found worthy to describe it as Bima Group and subsequently subdivide the lithological units into formations, vis; Lower, Middle, and Upper. Yolde Formation, which is only recognized in the Gongola Basin, has been mapped and now considered to be overlying the Bima Group in the study area. No any report or detail field evidence has ever been presented on the basin to consider the Yolde Formation as part of its stratigraphy; this is the first time it is reported as a stratigraphic unit within the basin. The previously known Gongila and Fika Shale Formations in the basin are now regarded as members within the Pindiga Formation in the Gongola Basin, because field evidence have shown that the Gongila village lies on the boundary between Middle Bima, Yolde Formation and Kanawa Member of the Pindiga Formation. In the present study Fika Shale is considered as a member because of the revised stratigraphy of the Gongola Basin. The Gongila Formation was previously considered to consist of two lithological units, i) the lower shale/limestone unit which is now considered as the Kanawa Member and ii) the upper shale/sandstone unit which is now regarded as the Dumbulwa Member. In the present study both the Gongila Formation and Fika Shale are now regarded as part of the Pindiga Formation. Upper conglomeritic sandstone forming a marked formational boundary was observed within the Kerri- Kerri Formation in the study area. The Chad Formation outcrops in the study area and overlie the Cretaceous sediments extending into the basin blanket over most of the Cretaceous sediments. Detailed facies analysis revealed facies groups: 1) Gravel Facies, consisting of sub- facies units, i) clast- supported conglomerates (Gcs), ii) clast- supported conglomerates grading into sandstones (Ggs), 2) Sandstone Facies (S) which consists of i) massive sandstones, (Ss) ii) crossbedded sandstones (Sx), iii) normally- graded sandstones (Sng) and 3) Mudstone Facies (M) which consists of i) silt- clay streaked layers (Msm) and ii) massive mudstone (Mm), and lastly 4) Carbonate Facies (C) mail composed of carbonate- rich layers. Analysis of architectural sedimentary elements also showed five elements which are; channels (CH, HO), sediment gravity- flow deposits (SG), sandy bedforms (SB), downstream- accretion macroforms (DA) and flood plain fines (FF). These elements are defined by their geometries and bounding surfaces. The overall petroleum geochemical results showed that Fe and Mn (siderophile) elements have the highest concentration value of inorganic geochemistry, which generally does not corresponds with most global results obtained in relation to elemental analysis with regards to crude oils and vii source rocks. In general, source rocks have higher geochemical values than crude oil samples if they mature, but in this study the concentration of the elements are mediocre which may be as a result of shallow depth of burial and lack of sedimentary cover over the targeted source rocks. The biophile elements Ni and V which are principal actors used in assessing petroleum potentials have lower values because of exposure and subsequent obliteration of their main constituent. Therefore, it can be concluded that, both the siderophile (Fe, Co, Mo, Cr, and Mn), chalcophile (Cu, Zn, Pb, and Cd) and biophile (V and Ni) elements have relatively low geochemical values for petroleum generation. Representative sandstone samples from different formations such as the Bima Group, Yolde Formation and Dumbulwa Member of the Pindiga Formation in the study area were classified on the basis of their mineral composition. Samples 4, 5, 7, 24, 27, 28, 34, 35, 36, 38, 40 and 41a are classified as arkosic arenites due to the high percentage of feldspar and quartz than rock fragments in majority of the samples, whereas samples 12, 21, 25 are classed as lithic arenites because rock fragments have higher mineral aggregate than feldspar. The compositional maturity of the sandstones was identified, the matured composed of arkosic arenites and the immature ones are related to lithic arenites. It can therefore be concluded that the Bornu is same as the Upper Benue Trough (Gongola Basin) based on the geological map produced, field relationship and geological setting. The Bornu Basin is no different from the adjacent basin except the sedimentation of the Quaternary Chad Formation
- ItemDEPLETION ANALYSES OF LOW ENRICHED URANIUM FUELS FOR THE NIGERIA RESEARCH REACTOR-1(2023-03)The use of advanced, accident-tolerant, Low Enriched Uranium (LEU) fuel types is one approach to improving the safety, security and fuel cycle performance of nuclear reactors. In spite of the acceptability of UO2 fuel, uranium-silicide and uranium-molybdenum fuels are being proposed in order to increases the accident tolerance of nuclear reactor cores. Although the as-built fuel of the Nigeria Research Reactor-1 (IRR-1) LEU core is 13% enriched UO2 clad in Zircalloy, previous research have demonstrated that specific uranium-silicide and uranium-molybdenum such as 19.75% enriched U3Si2, U3Si, and U9Mo dispersion LEU fuels clad in aluminum also present comparable neutronic characteristics within recommended safety limit for the NIRR-1 Miniature Neutron Source Reactor (MNSR). However, analysis of the depletion characteristics of the as-built UO2 core as well as the investigated fuel alternates are yet to be conducted as these data are important for optimization of safety, security, fuel management and decommissioning plan a well as conversion of other MNSRs from High Enriched Uranium (HEU) to LEU. Consequently, the SCALE 6.2.3 code system was used to develop new models of the NIRR-1 and perform criticality calculations and depletion analysis for the as-built UO2, U3Si2-Al, U3Si-Al, and U9Mo-Al LEU cores in the present study, using the HEU core as a benchmark. The results showed that the three Dimensional (3D) KENO-VI estimates of the Clean Cold Core Excess Reactivity (CCCER of the core are in good in good agreement with measured data with a bias of less than 4 %. Consequently, the 3D KENO-VI module of the SCALE 6.2.3 code can be used for criticality safety calculations of MNSRs and similar reactors. The neutron flux distribution data indicated a reduction in the magnitude of the average thermal neutron flux in the alternative LEU cores in the range of 7 – 10 % when compared to that of the HEU core. This implies that the thermal power of the U3Si2-Al, U3Si-Al, and U9Mo-Al LEU cores would have to be raised by their corresponding magnitude of percentage flux reduction to match the flux of the HEU core. However, the thermal neutron flux in the as-built LEU-UO2 core is essentially the same with that of the HEU core. Hence, the as-built LEU core will not compromise NIRR-1 utilization for thermal Neutron Activation Analysis. Although the results show that both the HEU and the LEU cores have a burnup of less than 1 % at the End of Cycle of 216 Effective Full Power Days (EFPD), the Uranium-Silicide fuels have a higher burnup when compared to the UO2 fuel. The depletion rates were estimated to be – 0.00120 mk/h, - 0.00124 mk/h, - 0.00123 mk/h and – 0.00105 mk/h for the as-built UO2, U3Si2, U3Si and U-9Mo LEU cores respectively. In all cases, the LEU cores depleted at a slower rate than the HEU core implying an improvement in the fuel economy of the cores compared to the HEU core. The core lifetimes after addition of top Beryllium Shim plates when the reactor is operated continuously for 216 EFPD were estimated to be 38.62, 37.34, 37.53, and 43.78 years for the as-built UO2, U3Si2, U3S i and U-9Mo LEU cores respectively. These estimated core lifetimes are 26% higher than that of the HEU. Consequently, the LEU cores show better fuel cycle performance and demonstrated an advantage of extended core lifetime for utilization in Neutron Activation Analysis. These results are useful in the development of a decommissioning plan for the NIRR-1 and fuel management of accident-tolerant alternative fuels to optimize their performance as promising alternatives to the UO2 fuel.
- ItemDEPLETION ANALYSES OF LOW ENRICHED URANIUM FUELS FOR THE NIGERIA RESEARCH REACTOR-1(2023-05)The use of advanced, accident-tolerant, Low Enriched Uranium (LEU) fuel types is one approach to improving the safety, security and fuel cycle performance of nuclear reactors. In spite of the acceptability of UO2 fuel, uranium-silicide and uranium-molybdenum fuels are being proposed in order to increases the accident tolerance of nuclear reactor cores. Although the as-built fuel of the Nigeria Research Reactor-1 (IRR-1) LEU core is 13% enriched UO2 clad in Zircalloy, previous research have demonstrated that specific uranium-silicide and uranium-molybdenum such as 19.75% enriched U3Si2, U3Si, and U9Mo dispersion LEU fuels clad in aluminum also present comparable neutronic characteristics within recommended safety limit for the NIRR-1 Miniature Neutron Source Reactor (MNSR). However, analysis of the depletion characteristics of the as-built UO2 core as well as the investigated fuel alternates are yet to be conducted as these data are important for optimization of safety, security, fuel management and decommissioning plan a well as conversion of other MNSRs from High Enriched Uranium (HEU) to LEU. Consequently, the SCALE 6.2.3 code system was used to develop new models of the NIRR-1 and perform criticality calculations and depletion analysis for the as-built UO2, U3Si2-Al, U3Si-Al, and U9Mo-Al LEU cores in the present study, using the HEU core as a benchmark. The results showed that the three Dimensional (3D) KENO-VI estimates of the Clean Cold Core Excess Reactivity (CCCER of the core are in good in good agreement with measured data with a bias of less than 4 %. Consequently, the 3D KENO-VI module of the SCALE 6.2.3 code can be used for criticality safety calculations of MNSRs and similar reactors. The neutron flux distribution data indicated a reduction in the magnitude of the average thermal neutron flux in the alternative LEU cores in the range of 7 – 10 % when compared to that of the HEU core. This implies that the thermal power of the U3Si2-Al, U3Si-Al, and U9Mo-Al LEU cores would have to be raised by their corresponding magnitude of percentage flux reduction to match the flux of the HEU core. However, the thermal neutron flux in the as-built LEU-UO2 core is essentially the same with that of the HEU core. Hence, the as-built LEU core will not compromise NIRR-1 utilization for thermal Neutron Activation Analysis. Although the results show that both the HEU and the LEU cores have a burnup of less than 1 % at the End of Cycle of 216 Effective Full Power Days (EFPD), the Uranium-Silicide fuels have a higher burnup when compared to the UO2 fuel. The depletion rates were estimated to be – 0.00120 mk/h, - 0.00124 mk/h, - 0.00123 mk/h and – 0.00105 mk/h for the as-built UO2, U3Si2, U3Si and U-9Mo LEU cores respectively. In all cases, the LEU cores depleted at a slower rate than the HEU core implying an improvement in the fuel economy of the cores compared to the HEU core. The core lifetimes after addition of top Beryllium Shim plates when the reactor is operated continuously for 216 EFPD were estimated to be 38.62, 37.34, 37.53, and 43.78 years for the as-built UO2, U3Si2, U3S i and U-9Mo LEU cores respectively. These estimated core lifetimes are 26% higher than that of the HEU. Consequently, the LEU cores show better fuel cycle performance and demonstrated an advantage of extended core lifetime for utilization in Neutron Activation Analysis. These results are useful in the development of a decommissioning plan for the NIRR-1 and fuel management of accident-tolerant alternative fuels to optimize their performance as promising alternatives to the UO2 fuel.
- ItemANALYSIS OF SET-UP ERRORS IN BREAST CANCER PATIENTS UNDERGOING EXTERNAL BEAM RADIOTHERAPYAT NATIONAL HOSPITAL ABUJA(2023-04)Radiotherapy plays an important role in breast cancer treatment. The main goal of radiationtherapy is to ensure tumor control while avoiding complications to the organs at risks. Uncertainty in the dose deposited in the tumor exists due to a variety of factors which include patient positioning errors. This study assessed and quantified breast cancer patients‟ set-up errors using an electronic portal imaging device and evaluated the dosimetric and biological impact in terms of generalized equivalent uniform dose (gEUD) using predictive models, such as Tumour Control Probability (TCP) and Normal Tissue Complication Probability (NTCP). About 200 breast cancer patients were considered at the Radiotherapy-Oncology department of National Hospital Abuja (NHA). Systematic and random errors were quantified, in addition,three-dimensional treatment planning was performed using CT scan images of the patients. The total prescribed dose was 5000 cGy per 25 fractions for most of the patients. The dosimetric and biological impact of these set-up errors on the target volume and the organ at risk (OARs) coverage were assessed by evaluating the Dose– Volume Histogram (DVH), gEUD, TCP and NTCP. The standard deviations (SDs) of the systematic set-up and random set-up errors were calculated for the Lateral, Anterior-Posterior and Superior-Inferior fields and were found to be 6.6055(4.477), 4.608(3.591), 11.432(8.1748) respectively. Thus, a planning target volume (PTV) margin of 5 mm was defined around the OARs, and around the clinical target volume (CTV). The toxicity of OARs was quantified using gEUD, TCP and NTCP. The data represented that NTCP values for conformal technique was one (1) for the combined lungs at D50, D75, D90 and D98 of the planning target volume (p = 0.05). In addition, NTCP values of the heart were equal to 0.99 at D50, D75, D90 and D98. The TCP outcome shows a negative and not so good correlation with calculated dose to 50%, 75%, 90% and 95% of the target volume (D95%). In conclusion, this research confirmed that more relevant and robust radiobiological parameters should be integrated with more recent dose calculation methods to obtain reliable prediction of organ at risks toxicity and avoid over/under estimating of TCP and NTCP. This is critical if medical decisions have to be based on NTCP estimations in routine practice.