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Search Results: 1 - 10 of 1972 matches for " Nnamdi Norbert Jibiri "
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Effects of Food Diet Preparation Techniques on Radionuclide Intake and Its Implications for Individual Ingestion Effective Dose in Abeokuta, Southwestern Nigeria  [PDF]
Nnamdi Norbert Jibiri, Tolulope Hadrat Abiodun
World Journal of Nuclear Science and Technology (WJNST) , 2012, DOI: 10.4236/wjnst.2012.23016
Abstract: The radioactivity measurements in food crops and their diet derivatives and farm soil samples from Abeokuta, one of the elevated background radiation areas in Nigeria have been carried out in order to determine the concentration levels of natural radionuclides (40K, 226Ra and 232Th). The activity concentrations of the natural radionuclides in the samples were determined via gamma-ray spectrometry using a 76 mm × 76 mm NaI(Tl) detector. Different common food crops representing the major sources of dietary requirements to the local population were collected for the measurements. The collected food crops were prepared into their different derivable composite diets using preparation techniques locale to the population. Using available food consumption data and the activity concentrations of the radionuclides, the ingestion effective doses were evaluated for the food crops and diet types per preparation techniques. For the tuberous food crop samples, the annual ingestion effective doses in the raw and different composite diets were 0.02 - 0.04 μSv and cumulatively 0.04 - 0.05 μSv while in the non-tuberous crops the doses were 0.44 - 0.70 μSv and cumulatively greater than 1 μSv respectively. Results of the study indicate that method of diet preparation is seen to play a major role in population ingestion dose reduction especially for tuberous crops than in non-tuberous crops. The study also showed that more ingestion dose could be incurred in diets prepared by roasting techniques. The result of the study will serve as a useful radiometric data for future epidemiological studies in the area and for food safety regulations and policy implementations in the country.
Natural background radiation dose rate levels and incidences of reproductive abnormalities in high radiation area in Abeokuta, Southwestern Nigeria  [PDF]
Nnamdi Norbert Jibiri, John Bamidele Famodimu
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.511141
Abstract:

A 10 y (1999-2008) birth records from two public and most accessible maternity hospitals locally in the city of Abeokuta, Nigeria were used to investigate the possible association of high outdoor gamma radiation exposure on reproductive abnormalities in the city. From the delivery record of 11,923 births in the period under study, a total number of 485 incidences of reproductive abnormalities were recoded. These incidences comprise 228 multiple births, 190 still births and, 67 premature births. Using the available terrestrial gamma radiation exposure data for the city and different reproductive abnormalities, regression assessment was carried out using the Pearson Product Moment (PPM) correlation statistics. The correlation showed that the incidences of reproductive abnormalities and the radiation dose levels were negatively correlated and correlation coefficient values were very low for each of the reproductive abnormalities considered. Factors such as socio-economic potentials of patients, dietary and other environmental factors may have substantial influence on the reproductive defects in the area other than radiation. However, the present study has added to the radiometric information needed in understanding the relationship between natural outdoor radiation exposure and occurrences of reproductive abnormalities in areas of high radiation in the country.

Radionuclide Contents and Physicochemical Water Quality Indicators in Stream, Well and Borehole Water Sources in High Radiation Area of Abeokuta, Southwestern Nigeria  [PDF]
Nnamdi Norbert Jibiri, Chijioke Micheal Amakom, George Olufemi Adewuyi
Journal of Water Resource and Protection (JWARP) , 2010, DOI: 10.4236/jwarp.2010.24033
Abstract: Water samples from streams, hand-dug wells and boreholes in high background radiation areas in Abeokuta, Nigeria have been collected in order to determine the activity concentrations of 40K, 226Ra and 232Th in the samples as well as their physicochemical characteristics. These parameters were evaluated in order to deter-mine the quality of these water sources to the local population, who use these water resources for drinking and domestic activities. Measurements of radioactivity in the water samples were carried out using γ-ray spectroscopy, while standard chemistry methods were used for the physicochemical determinations of these quality parameters. A total of fourteen representative water samples from streams (7), boreholes (4), and hand dug wells (3) were collected for study. The determined activity concentrations of the radionuclides in these samples were used to calculate the effective dose to the population from due to ingestion of and drink-ing the locally available water. The total annual ingestion effective doses were found to vary between 115.00 ± 1.15μSv and 1362.30 ± 438.02 μSv. The physicochemical parameters where found to be lower than the prescribed standard safe limits in the water sources except for the nitrate and phosphate levels which were particularly high in the water samples from boreholes and hand-dug wells. The radiation effective ingestion dose due to ingestion of water from dug wells and streams was found to be higher than the dose due to inges-tion of water from borehole sources in the studied areas. The results obtained in this study, have been taken as a baselines for physicochemical parameters and activity concentrations of natural radionuclides in water samples within Odeda and Obafemi-owode parts of Abeokuta, Nigeria.
Grain Size Analysis of the Sediments from Ogun River, South Western Nigeria
Itunu Comfort Okeyode,Norbert Nnamdi Jibiri
Earth Science Research , 2012, DOI: 10.5539/esr.v2n1p43
Abstract: The grain size analysis for thirty-two sediment samples from Ogun River was carried out. Mechanical sieving method using a Ro-tap shaker was chosen for the analysis. The cumulative frequency curve is obtained by plotting grain size (in phi scale) versus cumulative percent using the Probability paper. The phi values of the percentiles 5%, 16%, 25%, 50%, 75%, 84% and 95% were read off from the ogive curve that was plotted. These were used to calculate the statistical parameters of standard deviation, skewness, kurtosis and mean. 2.1 is the mean value for the grain size distribution within the analysed sediments with a graphic mean distribution for these sediments ranging from 1.09 to 2.90 phi, indicative of fine to medium grained sand. The standard deviation (sorting) shows a spread of of 0.54 to 1.42 phi and a mean value of 0.81. Most of the samples are moderate to poorly sorted with only a few being moderately well sorted. The skewness values of the samples ranged from -0.25 to 0.53, thus indicating the presence of fine fraction and coarse fraction in the particle population. The kurtosis is between 0.58 and 4.5, indicating that 38% of the samples are leptokurtic, 41% are very leptokurtic, 6% are mesokurtic and 15% is very platykurtic.
Genetically significant dose assessments of occupationally exposed individuals involved in industrial and medical radiographic procedures in certain establishments in Nigeria
Jibiri Nnamdi N.,Oguntade Grace T.
Nuclear Technology and Radiation Protection , 2007, DOI: 10.2298/ntrp0702053j
Abstract: The main source of radiation doses received by humans from man-made sources of ionizing radiation in medicine and industry comes from X-rays. The genetic risks of ionizing radiation effects on an individual who is occupationally exposed largely depend on the magnitude of the radiation dose received period of practice, workload and radiological procedures involved. In this work, using the linear non-thresh old model, we have at tempted to assess the level of genetic risk of occupationally exposed individuals in two medical and industrial establishments in Nigeria by estimating their genetically significant dose values. The estimation was based on continuous personnel radiation dose monitoring data for the individuals in each of the establishments over a three year period (1998-2001). The estimated genetically significant dose values in the years considered were 12 mSv for the medical, and 29 mSv for the industrial personnel. Appropriate radiation protection precautions should be taken by the personnel to adhere to standard operational practices in order to minimize the genetically significant dose resulting from radio logical practices.
Gross alpha and beta activities and trace heavy elemental concentration levels in chemical fertilizers and agricultural farm soils in Nigeria  [PDF]
N. N. Jibiri, K. P. Fasae
Natural Science (NS) , 2013, DOI: 10.4236/ns.2013.51012
Abstract:

The gross alpha (α) and beta (β) activities and trace heavy elemental concentrations have been determined in Single Super Phosphate (SSP) and Nitrogen Phosphorous Potassium (NPK) fertilizers samples used for agricultural purposes in Nigeria. Cultivated farm soil samples from two regions (north and south) in the country and samples of phosphate rocks were also analyzed for gross α and β radioactivity and elemental concentrations. The beta activity concentration in the NPK (15-15-15) fertilizers was found to vary from 2410.0 ± 80.0 Bq·kg–1 to 4560 ± 140.0 Bq·kg–1, between 1340.0 ± 70.0 Bq·kg–1 and 1440.0 ± 70.0 Bq

Exploiting Public Art, Architecture and Urban Design for Political Power in Abuja: Modernism and the Use of Christian, Islamic and Ancestral Visual Icons  [PDF]
Nnamdi Elleh, David J. Edelman
Current Urban Studies (CUS) , 2013, DOI: 10.4236/cus.2013.11001
Abstract:

Can public art, architecture and urban design be indices of the social, economic and political struggles for hierarchies and dominance among contesting interest groups within a postcolonial society like Nigeria? In 1975, the Nigerian military proposed that building a new Federal Capital Territory at Abuja would facilitate the country’s “federal character” resolve the problem of nepotism, and ease ethnic tensions among the two hundred and fifty cultural groups which constitute the nation (Afigbo, 1986; Ajayi, 1984)1. However, a study of the architecture and the sculptures at the newly constructed National Assembly Complex suggest otherwise. In this paper, it is argued that while the ideology of a nationalist architecture and the concept of a “federal character” might have merit for a multi-ethnic society like Nigeria, at Abuja, “federal character” instead became the means with which the emergent postcolonial elite consolidated its economic and political power through the exploitation of public art, as well as Modernist architectural and urban design elements using Islamic, Christian, and Ancestral visual icons.

Earnings-Dividend Relationship in Corporate Nigeria; A Test of Predictive Efficacy
ABC Akujuobi, IS Nnamdi
African Research Review , 2010,
Abstract: Prompted by the need for an empirical evaluation of the relationship between corporate net earnings and dividend payouts of quoted Nigerian firms as well as the search for a strong predictive model for this relationship, the study evaluates the predictive efficacies of current- and one- year- lagged earnings regression models among the Nigerian quoted firms. Applying the ordinary least square regression analysis on one hundred and four (104) firms selected as the study sample, the results indicate that dividend payouts are relatively more sensitive to current earnings per share compared to past earnings per share. Further, the percentage change in dividend payouts attributable to changes in current earnings per share is found to be relatively higher than that attributable to changes in past earnings per share, thus providing evidence that current earnings model is relatively more effective in predicting the dividend payouts of Nigerian quoted firms. The study recommends strong information dissemination to all stakeholders in the Nigerian capital market in order to improve market efficiency and potential benefits derivable from the market by all participants.
The Nigerian press coverage of political conflicts in a pluralistic society
Ekeanyanwu Nnamdi Tobechukwu
Global Media Journal : African Edition , 2011, DOI: 10.5789/1-1-46
Abstract: This paper evaluates Nigeria’s press coverage of political crises and conflicts during the President Obasanjo (Second Term) regime of 2003-2007. The major focus of this paper is to assess the role of the Nigerian press in the struggle for political positions, which breeds crises and conflicts especially in a pluralistic society. It is the position of the paper that the Nigerian press has not fared very well in reporting political conflicts and crises because of the advocacy position adopted by most of them. It is also observed that editorial influence on the part of publishers may not be unconnected with this trend. Using the content analytical research method as the main instrument of data generation, this paper submits that the Nigerian press has operated more as active players in political crises and conflicts than as an impartial judge of such crises and conflicts. This has negatively affected the management of such crises and conflicts. The paper therefore cautions against advocacy journalism in the Nigerian media industry and suggests more public participation in the media industry through “people” ownership. The press should also strive towards better professional and ethical practices in the industry and ensures that it only engages in constructive and balanced reporting of conflicts and issues.
The Impact of Thermal Modeling on Limiting RF-EMF  [PDF]
Norbert Leitgeb
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2013, DOI: 10.4236/jemaa.2013.54022
Abstract:

The paper quantitatively assesses the relationship between specific energy absorption rates (SAR) of radio frequency (RF) electromagnetic fields (EMF) and resulting intracorporal tissue temperature changes (ΔT) at whole body exposure of a small person to resonant RF EMF. Applied thermal modeling allowed accounting also for dynamic thermoregulatory responses. As expected from physical laws the correlation of all local SAR values and ΔT data was fairly good. However, at local level SAR proved to be only weakly associated with ΔT. Even if averaged, over any 10 g tissue the ratio ΔT10g/SAR10g still varied by almost two orders of magnitudes. Blood perfusion was found to play a major role in affecting local temperature changes and caused even net cooling. The results demonstrate that local SAR is a poor surrogate for local temperature change, and that conventional static thermal modeling underestimates body core temperature. Results demonstrated that recommended reference levels of RF EMF fail to reliably prevent from exceeding yet legally binding basic restrictions not only with regard to whole-body SAR

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