Evaluation of net radiation using the autoregressive models with higher orders over Nigeria

In this study, monthly surface net radiation data were collected from the Nigeria Meteorological Agency, Lagos covering a duration of 31 years (1983- 2013) spatially distributed across the four climatic regions: Semi-Arid (SAR), Sub-humid Dry (SHD), Sub-humid Humid (SHH) and Humid (HUM) regions. The net radiation was evaluated using different forms of Auto-Regressive models – AR {p} where p is the number of orders of the auto-regressive. The analysis showed that AR {4} performed best in all the regions and stations investigated. Regionally, AR {4} has maximum values of coefficient of determination of 0.8127 in HUM, 0.7876 in SHH, 0.5765 in SHD and 0.7973 in SAR regions. It can be concluded that the higher the order of auto-regressive models, the more accurate estimation of net radiation it will give irrespective of location in Nigeria

Regional Estimation of Solar Radiation using Routinal Meteorological Variables

In this paper, the monthly surface data of solar radiation, minimum and maximum temperatures, wind speed and evaporation of 1970-1995 for four climatic regions in Nigeria were obtained from the archives of Nigerian Meteorological Agency (NIMET), Oshodi, Lagos. The distributions of solar radiation with each of the four meteorological variables were observed. It was found that solar radiation was well monitored by each of the variables indicating that the linear combination of the variables can be used to develop model from where solar radiation data can be evaluated. Consequently, the multivariate linear regression model was developed using 1970-1990 data of the five meteorological parameters for each of the four regions taking solar radiation as dependent variables and the four other meteorological variables as independent variables. The models were validated using 1991-1995 data of minimum and maximum temperatures, wind speed and evaporation to obtain the predicted solar radiation. Analyses have shown that over seventy percent correlations exist between the measured and estimated values of solar radiation. The efficiency of the developed models was further verified by calculating the values of R 2, MBE, RMSE and t-test at confidence level of p < 0.05. The results obtained showed that the models were statistically significant and could be used to estimate solar radiation at the regions in Nigeria. Keywords: Distribution, Meteorological, Multivariate, Radiation and Statistically

Female infertility and patriarchy: A reflection on medical science and biblical position

Marriage traditionally has been based upon gender relations that prescribed authority of husband over wives. The rituals of throwing rice to symbolize fertility and the woman's obligation to bear and raise children also illustrate normative gender relations. In other words, in the home, infertile women feel and bear most the consequences of masculine power and privileges. In the main, the paper discussed the medical science aspects of female infertility which explain that both sexes are liable to infertility. This could be as a result of several factors like damage to fallopian tube, hormonal cause, age, smoking cigarettes, sexually transmitted infections, overweight and the likes. However, the study showed that infertility hinges on patriarchy in both the bible and Yoruba culture which was cited as example. In both cases, childlessness is viewed as female problems and the depression experience by such women areequivalent to suffering from terminal illness. The paper therefore argues for the exercising of “equal partner” model where the traditional marriage contract of shifting blame of infertility on women is completely disrupted. In other words, neither partner is more likely to perform provider roles. In practice, this might mean intentional sharing of blame, ridicule, abuse, segregation and violence associated with infertility.Keywords: Infertility, Patriarchy, Women, Medical Science, Violence

Growth and Migration of Benthic Habitats: A Spatial Microsimulation Approach

Spatiotemporal visualization of the impact of geomorphological changes in coastlines benthic habitats can generate insight needful in understanding the spatial ecology of seafloors and in anticipating the location, growth and migration of marine sanctuary and marine protected areas (MPAs). Such understanding has implication for effective development and conservation of these MPAs. To date, there are limited studies that have applied complex adaptive systems (CAS) to investigate the impact of geomorphological changes on the location, growth and migration of benthic habitats. Also, there is a gap in our knowledge of the marine geographical information system (marine GIS). To fill these gaps in the literature, we propose the use of the CAS theory as a lens to study the growth and migration of underwater (benthic) habitats in the Hawaii coastline using bathymetric SoNAR Multibeam data. We investigate the research question that concerns whether spatial approach helps in understanding the impact of projected geomorphological changes on patterns of growth and migration of benthic habitats of Hawaii coastlines. We develop a spatiotemporal IT antifact that engages a prediction machine to project individual data units (micro-data) to future states based on geomorphological changes using dynamic spatial microsimulation based method. The results of our study provide evidence of the contributions of spatial approach to understanding benthic habitat. The results also present research and practical implications for marine exploration and resource managers, and governments

Application of nonlinear autoregressive neural network to estimation of global solar radiation over Nigeria

In this paper, surface data meteorological were used as input variables to create, train and validate the network in which global solar radiation serves as a target. These surface data were obtained from the archives of the European centre for Medium-Range weather forecast for a span of 36 years (1980-2015) over Nigeria. The research aims to evaluate the predictive ability of the nonlinear autoregressive neural network with exogenous input (NARX) model compared with the multivariate linear regression (MLR) model using the statistical metrics. Model selection analysis using the index of agreement (dr) metric showed that the MLR and NARX models have values of 0.710 and 0.853 in the Sahel, 0.748 and 0.849 in the Guinea Savannah, 0.664 and 0.791 in the Derived Savannah, 0.634 and 0.824 in the Coastal regions, and 0.771 and 0.806 in entire Nigeria respectively. Meanwhile, error analyses of the models using root mean square errors (RMSE) showed the values of 1.720 W/m2 and 1.417 in the Sahel region, 2.329 W/m2 and 1.985 W/m2 in the Guinea Savannah region, 2.459 W/m2 and 2.272 W/m2 in the Derived Savannah region, 2.397 W/m2 and 2.261 W/m2 in the Coastal region and 1.691 W/m2 and 1.600 W/m2 in entire Nigeria for MLR and NARX models respectively. These showed that the NARX model has higher dr values and lower RMSE values over all the climatic regions and entire Nigeria than the MLR model. Finally, it can be inferred from these metrics that the NARX model gives a better prediction of global solar radiation than the traditional common MLR models in all the zones in Nigeria

The Limits of State Sovereignty: Darfur Crisis and the United Nations

The genocide in Darfur, Sudan has left over 300,000 dead, thus bringing the death toll in the entire Sudanese conflicts from 1956 to almost 2 million people and the number of displaced persons to over 2 million. The exacerbation of the crisis is traceable to government’s complicity exemplified by its standing order to the United Nations to stay off and evacuate its monitors in what it considered an entirely Sudanese affair that could be resolved without external interference. However, considering the limits of state sovereignty in a modern international system, where membership of the UN, the existence of the Geneva Convention on the Laws of War, Humanitarian Law and other subsisting legal frameworks on war crimes erode absolute sovereignty, the Sudanese government cannot hide under the non-interference in the internal affairs of states clause to prevent the international community from intervention in Darfur. This probably explains the recent approval by the Government of Sudan to finally allow a joint UN-AU troops to restore security, bowing to intense international pressure to do so

Effect of the inclusion of Galium in normal Cadmium chloride treatment on electrical properties of CdS/CdTe solar cell

The inclusion of gallium into the well-known CdCl2 post-growth treatment shows drastic improvement in both CdTe material and electrical properties of the fully fabricated CdS/CdTe-based solar cell as compared with the regular CdCl2 treatment. The optical, morphological, compositional and electronic properties the glass/FTO/n-CdS/n-CdTe/p-CdTe were explored after post-growth treatment of glass/FTO/n-CdS/n-CdTe/p-CdTe with CdCl2 and CdCl2:Ga treatments at 430 °C for 20 min. Morphological analysis show grain growths within the ranges of (100 – 2000) nm and (200 – 2600) nm for CdCl2 and CdCl2:Ga treatments as compared with the as-deposited glass/FTO/n-CdS/n-CdTe/p-CdTe layer with grain size within the ranges of (100 – 250) nm. Structurally, the preferred orientation of the as-deposited CdTe remains (111)C after both CdCl2 and CdCl2:Ga treatments of glass/FTO/n-CdS/n-CdTe/p-CdTe with randomisation of crystallite orientation observed after CdCl2:Ga with an increase in the diffraction intensities of the (220)C and (311)C CdTe peaks. The multilayer structure glass/FTO/n-CdS/n-CdTe/p-CdTe utilised in this work was grown using electrodeposition technique. The glass/FTO/n-CdS/n-CdTe/p-CdTe sample was divided into three sets; the first and second sets were treated with CdCl2 and CdCl2:Ga respectively, while the third set was left as-deposited. Both the CdCl2 and CdCl2:Ga sets were heat treated in air at 430°C for 20 min, etched to improve metal/semiconductor interface and metallised with 100 nm Au contacts. The current-voltage measurements show comparative improvements in the open-circuit voltage, short-circuit current density, fill factor and the solar cell efficiency of the CdCl2:Ga treated glass/FTO/n-CdS/n-CdTe/p-CdTe as compared with the CdCl2 treated structure. A conversion efficiency of ~11% was achieved with the CdCl2:Ga treatment while ~7% was achieved with the CdCl2 treatment of similar glass/FTO/n-CdS/n-CdTe/p-CdTe device structure. This observation shows that the inclusion of gallium further improves CdCl2 treatment of CdS/CdTe-based solar cell due to its unique features of improving the stoichiometry of the CdTe layer