Wollega University (WU), also known as Nekemte University, is a university in Nekemte, a town in the Western Oromia Region of Ethiopia..
In this work, we synthesized gadolinium (Gd3+) and aluminum (Al3+) co-doped calcium oxide (CaO) nanoparticles using a green sol-gel route with guava leaf extract as the capping agent. This synergistic co-doping strategy suppressed thermal-induced grain growth and improved the structural stability of pristine CaO nanoparticles. X-ray diffraction (XRD) analysis confirmed that the samples maintained a single-phase cubic rock-salt framework. However, significant lattice strain was induced due to the ionic size mismatch between the dopant ions and the Ca2+ host lattice. This mismatch compressed the average crystallite size from 25.40 nm to 13.46 nm, while increasing both lattice microstrain and X-ray density. Scanning electron microscopy (SEM) revealed a morphological transformation from large spherical particles to clustered flake-like nanostructures with reduced particle size. Energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) confirmed the successful incorporation of Gd and Al into the CaO lattice, the Ca2+ oxidation state, and the presence of lattice oxygen and oxygen-vacancy-related surface species. The optical results showed a progressive decrease in the optical band gap from 3.66 eV for pristine CaO to 3.46 eV for the sample containing 3 mol% Gd3+/Al3+. This band-gap narrowing is attributed to dopant-induced modifications of the electronic structure and defect-related states associated with incorporating Gd3+ and Al3+ into the CaO matrix. Thermogravimetric and differential thermal analyses (TGA/DTA) showed a clear three-stage mass loss. The residual plant organics burned away completely below 350°C and intermediate carbonate phases decomposed between 600°C and 750°C, leaving a phase-stable profile above 800°C. These composition-dependent structural, optical, and thermal modifications demonstrate the potential of the co-doped CaO nanoparticles for applications requiring tunable physicochemical properties.
In this study, we conduct a theoretical and computational exploration of topological phase transitions, spin-orbit interactions, and the dynamics of multipartite entanglement within a parabolically confined three-electron semiconductor quantum dot (QD) system made of gallium arsenide (GaAs). The system is influenced by varying confinement strength and an external perpendicular magnetic field (B). Utilizing a Full Configuration Interaction (FCI) exact diagonalization approach based on single-particle Fock-Darwin orbitals, we performed numerical analyses with MATLAB R2017a, investigating the interactions among Coulomb repulsion, Rashba and Dresselhaus spin-orbit coupling (SOC), and Dzyaloshinskii-Moriya (DM) anisotropic exchange interactions. By mapping the low-energy multi-electron Fock space to an effective three-qubit spin density matrix p(spin), we assess genuine tripartite entanglement metrics such as the 3-tangle (tau(3)) calculated using Cayley's hyperdeterminant, pairwise concurrence (C-ij), and tripartite negativity (N-3). Our findings indicate that topological phase boundaries marked by abrupt changes in sub-band Chern numbers (C) and Berry curvature singularities are linked to significant, non-analytic changes in the topology of spin entanglement. Notably, an increase in confinement strength and the magnetic field propels the system through ground-state level crossings, leading to a transition from a low-field spin-doublet (S=1/2) regime, characterized by distributed W-class Entanglement, to a maximally entangled GHZ-class state (tau 3 -> 1.0) around B approximate to 2.2T. Additionally, we identify a magnetic field-induced Entanglement Sudden Death (ESD) occurring at elevated fields (B>4.5T), which results from wavefunction compression that leads to the decay of inter-dot exchange J(B) and Zeeman-induced polarization into an unentangled product state (S=3/2). We also examine thermal sudden death trajectories (TSDE) at finite temperatures (T), establishing optimal operational conditions for three-qubit quantum registers within semiconductor nanostructures.
Enhancing common bean productivity in western Ethiopia requires understanding genetic variability and trait interrelationships for the Bako region’s specific agro-ecology. This study assessed twenty common bean varieties using a randomized complete block design with three replications at Bako Agricultural Research Center during 2024. Data on eleven agronomic traits were analyzed using variance, genetic parameters, correlation, path analysis, and disease scoring. Analysis of variance revealed highly significant differences (P ≤ 0.01) among varieties for all traits. High genotypic and phenotypic coefficients of variation were observed for hundred seed weight (32.91
Solar-powered irrigation Systems (SPIS) are critical for agricultural production enhancement, food security and climate change adaptation, especially in Arid and Semi-Arid Lands (ASAL). There is increased attention towards shifting to more abundant and cleaner energy potential sources for revitalising irrigation strategies in ASAL areas. This study employed a geospatial approach to identify suitable locations for solar-powered irrigation systems (SPIS) in Baringo County, Kenya. Based on an integrated use of GIS spatial analysis and analytical hierarchy procedure (AHP), suitable locations for solar-powered irrigation were mapped. Precipitation, irrigated areas, proximity to rivers, slope, and solar radiation were analysed and processed to derive spatially explicit SPIS suitability classes ranging from very low to very high suitability. The thematic layers were assigned weights based on Saaty’s AHP method, where weights for each factor were determined from a pairwise comparison matrix, and a Weighted Linear Combination (WLC) approach was used to derive the final suitability classes for the county. The findings reveal that approximately 58
Warfarin is widely used to prevent thromboembolic events; however, achieving optimal anticoagulation control remains challenging. In Africa, Time in Therapeutic Range (TTR) is generally low, and no nationally representative pooled estimate exists for Ethiopia. To estimate adequate anticoagulation control (TTR ≥ 65
