STATISTICAL ANALYSIS OF TEMPORAL VARIATIONS IN INDOOR RADON DATA USING AN ADAPTED RESPONSE SURFACE METHOD

Temporary variations in indoor radon data (IRD), comprising radon concentration (RC), air temperature, relative humidity and barometric pressure were monitored hourly over a period of two months in a bungalow house in Abeokuta, Nigeria. A total of 1510 data was assembled and analyzed statistically using Shapiro-Wilk for normality test, response surface method (RSM) and adapted response surface method (ARSM) to investigate and model the influence of the meteorological parameters on the variations of RC in indoor air. The overall results showed that RC varies widely over time and correlates positively with relative humidity and temperature, but negatively with barometric pressure. Specific results of the two response surface methods were compared and contrasted and the multiple linear regression model of the ARSM was highlighted and established as the appropriate method for analyzing IRD. ARSM was presented in an easily reusable form that can easily be adopted by researchers and data analysts.ª¤

HIERARCHICAL MODELLING OF INDOOR AND OUTDOOR (RESIDENTIAL) RADON DATA (RRD)

This work, proposes a Hierarchical Modelling (HM) for the indoor and outdoor Residential Radon Data (RRD). Indoor RRD and outdoor RRD are seen as distinct «¤??hierarchies«¤?? of carcinogenic radioactive radon and both hierarchies constitute the least exposure that can be experienced by an individual. Works on this issue have always been based on complicated models, even for single instances of both indoor and outdoor residential radon. Our proposed method can be used to analyse effectively the many-to-many (it, however, becomes numerically clumsy if more than 5-to-5 instances are considered) instances of residential radon, although we have illustrated, here, using a three-to-three situation. Our preference of this method is based on its simplicity, and probable higher precision, as compared with the complexity involved in other methods on the same issue. The data used for the illustration of our models were taken from the indoors (i.e. living-room, bedroom and the kitchen) and the rest outdoors (i.e. verandah, car-park and the well-water shed) of a residential building in a lightly populated estate (i.e. Asero housing estate). Observations were taken on a daily basis throughout the dry season covering ninety days (i.e. January, February and March), this constitutes our season I (i.e. dry). The same was repeated in the season II (i.e. wet) which was taken at the beginning of June through July and August.ª¤?ª¤?ª¤?ª¤?ª¤?ª¤?ª¤?ª¤

Solitary colonic neurofibroma in an African child

Neurofibromas are a group of heterogeneous neurocutaneous disorders. They are benign neoplasms consisting of neural and connective tissue components affecting any organ system. Gastrointestinal involvement in neurofibromatosis type 1 (NF1) are rare and are late manifestations of the disease, but in exceptional cases they can be the initial sign of neurofibromatosis in patients who have no external stigmata that arouse suspicion. Neurofibromatosis of the colon as a part of the NF1 is rare. Isolated colonic neurofibromatosis without other features suggestive of NF1 is rarely encountered in clinical practice. We report the case of a 12-year-old boy with an isolated colonic neurofibromatosis presenting with a right hypochondrial mass with no external features of NF1. We report this case as its presentation in children may give a diagnostic dilemma and the probability of malignant digestive disease associated with NF1 should be kept in mind, regardless of the age of the patient.Keywords: children, colonic, neurofibroma, rare, solitar

AN ENHANCED TECHNOLOGY ACCEPTANCE MODEL TO MEASURE CUSTOMERS’ WILLINGNESS TO PAY MORE FOR SECURE SOFTWARE DEVELOPMENT

Securing information system (IS) has become a critical concern within many sectors of business organisations with significant resources being devoted to the control of security threats. Recently, it has been discovered that incorporating security at the time of development is the best option for having a robust system. This study explores factors that motivate IS owner’s willingness to pay extra cost for a secure software development and validates the relationships among the various variables. Enhanced Technology Acceptance Model (TAM) was used to investigate the factors that influences IS owner’s willingness to pay extra cost for secured software development. Out of all the constructs considered, Self-Efficacy (SE) is found to be significant (β= 0.617, P<0.05) which suggests that self-efficacy is useful for investigating willingness to pay for a secure software development. In addition, the strength of the linear association between Self-Efficacy and Behavioural Intention (BI) (R2 =0.354) implies that Self Efficacy has direct moderate impact on Behavioural Intention to pay extra cost for a secure software development.

Performance evaluation of 200W solar photovoltaic panel considering Bauchi microclimatic conditions

Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. This paper focuses on optimizing the performance of 200W solar module taking into consideration the local climatic conditions of Bauchi locality. The uncertainty in life cycle savings for solar thermal and photovoltaic (PV) systems as linearly correlated with uncertainty in solar resource data. These uncertainties paved way for the need to conduct a critical assessment of the resource. Assessment of the solar resource for these technologies rely upon measured data, where available. In this paper, we present the development of mathematical model of photovoltaic solar cells based on their detailed single diode equivalent circuit representation. Pertinent simulation models for PV solar module both for an ideal weather situation and for taking into consideration the effects of microclimatic conditions that prevail in Bauchi as evaluated and compared with benchmarks available. The complete model of the PV system was implemented using MATLAB/Simulink platform. The standard characteristic curves for the 200W solar panel are as presented. The simulation of the ideal PV system made use of standard test conditions (STC) to facilitate comparison with the existing benchmark results in the literature. The analysis of the characteristics performance curves returned an average VOC = 42.9v and ISC = 4.21A. The simulation results further revealed that the power delivered by the 200W monocrystalline solar module of 144.3W @620W/m2, 35ºC as recorded for Bauchi under all climatic conditions as evaluated. The benchmark values obtained in the laboratory are VOC = 45.5V, ISC = 5.92A and 200-W under the Standard test condition (STC) conditions of cell temperature 25ºC, solar irradiance of 1000W/m2 and air mass (AM) of 1.5. The average conversion efficiency and fill factor as evaluated are 0.77 and 16% respectively. This result agrees with the benchmark of module efficiency of >15.66% recorded at STC. The results conclusively reveal that the microclimate of a locality essentially affects the performances of solar PV systems deployed to each location on the globe. Therefore, utilization of these parameters is essential for consideration in the design of solar systems in all localities

INVESTIGATION OF FACTORS AFFECTING CLOUD COMPUTING ADOPTION IN NIGERIA

Cloud computing is a viable alternative for meeting the technological needs of many  enterprises with the benefits of instantaneous computing resource fulfillment, technology expenditures at lower costs, common technology platforms that can facilitate standardization and decreased  need for internal technology support personnel. This paper examined the behavioral intention to adopt cloud computing services in large and small organization using an Enhanced Technology Acceptance Model (ETAM). The aim is to investigate the factors affecting cloud computing adoption in Nigeria. The model includes variables that other research has found related to adoption of new computing services and technologies. Regression Analysis was then deployed to test the research hypotheses. The result of regression analysis revealed that attitude and adopters ability to use cloud computing (self-efficacy) were better predictor of intention; perceived usefulness and perceived ease of use of cloud computing were better predictor of attitude; perceived ease of use and the relevant of cloud computing to adopters’ work (job relevance) were the predictor of perceived usefulness.

Self‑perceived seizure precipitants among patients with epilepsy in middle‑belt Nigeria

Aim: Patient’s perception of seizure precipitant is crucial in epilepsy management, but it is often overlooked by physicians. This may be due to neglect and underestimation of its importance. This study looked at frequency and nature of self‑perceived seizure precipitants among patients with epilepsy.Materials and Methods: A close‑ended questionnaire‑based study. Patients with active epilepsy (≥2 attacks/year) were recruited from the neurology clinic of the University of Ilorin Teaching Hospital (UITH), Ilorin.Result: A total of 89 patients participated in the study and of these 41 (46.1%) were males. Their median age was 30 (21-52) years and median age at seizure onset was 22 (15-46) years. The median seizure duration was five (2-14) years. More patients (46.1%) had less than secondary school education and 12 (13.5) were uneducated. Generalized epilepsy was the predominant (68.6%) seizure type. A total of 33 (37.1%) subjects had ≥4 attacks/year, 29 (32.6%) had 5-12 attacks/year, and 27 (30.3%) >12 attacks/year. A total of 16 (18%) subjects did not mention any seizure precipitant, whereas 73 (82.2%) reported at least one specific seizure precipitant; of these, 62 (85%) patients reported ≥2 precipitants. Stress (41%), inadequate sleep (27%), and head trauma (26%) were the three leading seizure precipitants mentioned. Subject’s age, sex, level of seizure control, and place of abode did not influence reported seizure precipitants. However, the more educated (>12 years education) patients significantly reported stress as seizure precipitant (P < 0.05). Most (80%) patients rightly indicated that antiepileptic drug was the best treatment for their seizure control.Conclusion: The result of this study showed that the leading perceived seizure precipitants among epilepsy patients attending the neurology clinic of UITH were stress, inadequate sleep, head trauma, and demonic attacks and spells.Keywords: Perceived‑seizure‑precipitant‑ epilepsy ‑Nigeria

Urinary Schistosomiasis and Its Potential for Cancer and Hepato-Renal Function Alterations among the Residents of Asejire Dam, South-Western Nigeria

Urinary schistosomiasis is of public health significance in sub-Saharan Africa with its prevalence being linked to carcinogenesis. However, there is a paucity of data to support this relationship. This study explored the prevalence and intensity of Schistosoma haematobium infections and its associations with cancer and hepatorenal function alterations in villages along the Asejire dam in the State of Osun, Nigeria. Urine samples from 152 consented participants (aged 18–75 years) from four communities were collected and examined for Schistosoma haematobium using the microscopy method. The blood serum of randomly selected infected and non-infected individuals (10 per group) was screened for tumor, inflammatory and hepato-renal function biomarkers. From the results, only one out of the four communities recorded cases of schistosomiasis with a prevalence of 26.5% (22/83) and overall infection prevalence was 14.47% (22/152). There was no statistical difference (p ˃ 0.05) in kidney, liver antioxidants, and lipid peroxidation markers in the infected and non–infected participants. The concentrations of antioxidants, inflammatory, and tumor markers were higher in Schistosoma infected individuals as compared with non-infected individuals. This justifies the need to monitor schistosomiasis-infected individuals for tumor, inflammatory and hepato-renal function biomarkers before they develop into cancer, liver, and kidney failure. Keywords:    Urinary Schistosomiasis; tumor; and inflammatory markers; antioxidants; hepato-renal function; Asejire dam Nigeri

Effect of Unified Power Flow Controller on Power System Performance: A Case Study of Maryland 132/33/11 kv Transmission Station

This work examines the effect of Unified Power Flow Controller (UPFC) on power system performance using Maryland 132/33/11 kV transmission station as a case study. The transmission network consists of Alausa, Police Training College and Mushin 33 kV feeders and T1A-15 MVA, T2A-15 MVA and T3A-15 MVA 33/11 kV tertiary transformers with their respective peak load designated A-F. The developed model equations for the network without and with UPFC were implemented using Matlab/Simulink software (R2009b Version). The system’s performance was further examined by introducing a fault condition on D and E transformers. With A-F as 25, 37.5, 12.5, 12.5, 12.5 and 37.5 MW respectively, the average voltage improved from 0.95297, 0.93832, 0.93952, 0.93123, 0.91937 and 0.95297 p.u. respectively without the UPFC to 0.96142, 0.95560, 0.94782, 0.93838, 0.92755 and 0.96142 p.u. respectively when the UPFC was applied. Similarly, the average power improved from 3.55883, 6.85067, 9.8335, 12.4735, 14.74483 and 6.85067 MW respectively without the UPFC to 3.62233, 6.97133, 10.0095, 12.6952, 15.0113 and 6.97133 MW respectively with the UPFC. Also, for the earth fault introduced on D and E transformers, the average voltage improved from 0.4467 and 0.84005 p.u. respectively without the UPFC to 0.4507 and 0.8475 p.u. respectively with the UPFC. The average power similarly improved from 1.9435 and 5.3665 MW respectively without the UPFC to 1.9775 and 5.4625 MW respectively when the UPFC was applied. The results of this work showed that the application of UPFC on the Maryland transmission network appreciably improved the voltage and power profiles of the system