Yobe State University is located in Damaturu, Yobe State Nigeria. It was established under the [Yobe state] law in 2006 by Alh. Bukar Abba Ibrahim, the then Executive Governor of Yobe State(1999-2007).
This study assessed the distribution and radiological hazards of radionuclides (238U, 232Th, and 40 K) in soil samples from Keffi, North-Central Nigeria. Using gamma-ray spectrometry, the mean activities were 27.5 ± 24.3 Bq kg− 1 (238U), 13.75 ± 8.4 Bq kg− 1 (232Th), and 1502.5 ± 1501.3 Bq kg− 1 (40 K). High variability, skewness, and kurtosis indicated geological heterogeneity. Sample S1 showed the highest radionuclide levels, correlating with intense gemstone mining. Radiological indices (Raeq, Hex, Hin, ADR, Iγ) revealed localized hazards, with S1 exceeding safety thresholds. Correlation and PCA analyses confirmed strong relationships among radionuclides and hazard parameters, explaining over 98
Nigeria’s Fourth Republic witnessed seven uninterrupted presidential and other elections from 1999, an unprecedented feat that signalled stability in Nigeria’s democratic experiment. From 1999 to 2019, presidential elections exhibited the same character and predictability, but the 2023 Presidential Election was different in many ways. This study analyses in detail the emerging issues that heralded the process and conduct of the 2023 Presidential Election and carefully highlights the new developments and changes. The study is based on an interview method research design and data were collected from various sources including both primary and secondary sources. Documented sources were used to complement the other data sources. The collected data was grouped and analysed using thematic interpretations. The study reports that the 2023 Presidential Election portrayed some significant changes from what was obtained including the emergence of a third force, the controversy over the 25 per cent Federal Capital Territory Abuja requirement and the Bimodal Verification Accreditation System issue. The study concludes that these unprecedented issues affected voting behaviour and the outcome. The study recommends, among other things, that Nigeria should consider the option of fully digitised voting and remove the constitutional ambiguities surrounding the minimum requirements for declaring a winner.
Discussions at a recent conference on microscopy technology dissemination spotlighted the importance of setting technology adoption capable of producing scientific outcome as the end goal. This Comment examines current global efforts in microscopy dissemination and summarizes the challenges and paths forward.
Tin-based perovskite solar cells (PSCs), particularly methylammonium tin triiodide (MASnI3), have emerged as promising lead-free alternatives to conventional lead-based devices. However, their performance is significantly limited by defect-induced recombination and thermal instability. In this work, a systematic SCAPS-1D simulation study is conducted to investigate the coupled effects of absorber thickness, bulk defect density, interface defect states, band alignment, and operating temperature on device performance. The simulation model is constructed using experimentally reported material parameters and benchmarked against literature-reported efficiency ranges (5–9%) to ensure physical relevance. Results indicate that an optimal absorber thickness of 600 nm yields a power conversion efficiency (PCE) of 17.31%, representing a balance between optical absorption and carrier transport. Bulk defect density is identified as the dominant performance-limiting factor, with PCE decreasing sharply from 25.05% to 4.47% as defect density increases from 10⁹ to 10¹⁶ cm⁻³ due to enhanced Shockley–Read–Hall recombination. Interface analysis reveals that the MASnI3/Spiro-OMeTAD junction is more sensitive to defect states than the TiO2/MASnI3 interface, leading to significant degradation in fill factor and current density at high trap densities. Band alignment optimization indicates that small positive offsets (0 to +0.20 eV) can suppress interfacial recombination while maintaining efficient charge extraction. Temperature-dependent analysis demonstrates performance improvement up to ~400 K, followed by degradation due to increased recombination and bandgap narrowing. Although the study is based on numerical simulation without direct experimental validation, the results are consistent with experimentally observed trends and provide semi-quantitative insights. The findings therefore offer practical design guidelines rather than absolute performance predictions, highlighting critical defect thresholds and interface engineering strategies for improving MASnI3 solar cell performance.
A central problem in distribution theory is the construction of flexible models that retain analytical tractability while improving shape adaptability in applications. We propose a sine-transformed extension of the Nakagami distribution by applying a trigonometric mapping to the baseline cumulative distribution function. The resulting sine-transformed Nakagami model preserves the original two-parameter structure, admits closed-form expressions for both the distribution and density functions, and yields tractable reliability measures. We establish key structural properties, including validity, smoothness, and well-defined support; in addition, a hazard modulation representation relative to the classical Nakagami model is derived; and obtain explicit upper-tail asymptotics showing that the proposed transformation preserves the light-tailed class while modifying survival decay in a controlled and interpretable manner. Series representations are developed to facilitate the computation of moments and other related functionals. Parameters are estimated by maximum likelihood using numerical optimization, and finite-sample performance is evaluated through Monte Carlo simulation studies. Applications to real data illustrate that the sine-transformed Nakagami distribution provides an improved goodness of fit compared with the classical Nakagami model for reliability-type data.
