Dye-sensitized solar cells (DSSCs) have undergone a decisive transition from efficiency-driven laboratory devices to stable, scalable, and application-oriented photovoltaic systems during the period 2020–2025. This review critically analyzes approximately 100 representative and influential DSSC research articles published during the 2020–2025 period, selected on the basis of device performance, operational stability, materials innovation, and relevance to emerging indoor photovoltaic and IoT applications. Particular emphasis is placed on the emergence of copper-based redox mediators, the transition toward quasi-solid and solid electrolytes, advances in photo stable organic sensitizers, and the development of monolithic device architectures. Recent progress has enabled DSSCs to demonstrate indoor power conversion efficiencies (PCEs) exceeding 13% under low-intensity artificial illumination, along with operational lifetimes beyond 10,000 h under controlled indoor testing conditions. Recent progress has enabled DSSCs to demonstrate indoor power conversion efficiencies exceeding 13% under low-intensity artificial illumination, along with operational lifetimes beyond 10,000 h under controlled indoor testing conditions. These advances position DSSCs as leading candidates for indoor photovoltaics and Internet-of-Things (IoT) energy harvesting applications.

Magnetite (Fe₃O₄) nanoparticles exhibit complex charge transport behavior governed by mixed-valence electronic structure and defect chemistry. In this study, Fe₃O₄ nanoparticles were synthesized via a controlled co-precipitation method under an inert atmosphere to preserve Fe²⁺ states and suppress secondary phase formation. X-ray diffraction confirms the formation of a nanocrystalline inverse spinel structure with an average crystallite size of ~16 nm. Morphological analysis reveals quasi-spherical, agglomerated nanoparticles. Photoluminescence spectra exhibit distinct emission bands in the visible and near-infrared regions, attributed to defect-mediated recombination involving oxygen vacancies and localized states. Temperature-dependent electrical measurements reveal non-linear semiconducting behavior with an anomalous decrease in resistivity in the 283–293 K range. This behavior is attributed to defect-assisted percolative conduction and thermally activated small polaron hopping rather than any intrinsic phase transition. The study establishes a direct correlation between defect-induced optical states and electrical transport mechanisms. The findings provide important insights into defect-engineered transport phenomena in Fe₃O₄ nanostructures for potential applications in sensing and electronic devices.

This review provides a comprehensive, processing-centric synthesis of four decades (1986–2025) of rice husk ash (RHA) research, linking combustion chemistry, purification, mechanical activation, and fabrication routes to microstructural evolution and material performance in metal matrix composites (MMCs), cementitious systems, and geopolymers. A consistent finding is an optimal reinforcement window of 4–10 wt.% RHA, achieving significant improvements in hardness (32–55%), tensile strength (28–38%), wear resistance (40–60%), compressive strength (10–25%), elastic modulus (10–30%), and damping capacity (18–35%), while avoiding particle clustering and porosity at higher loadings. Fabrication routes including stir casting (scalable, 2–10 wt. % RHA), powder metallurgy/spark plasma sintering (superior densification, 0–20 wt. % RHA), and friction stir processing (40–50% surface hardness increase) are critically evaluated. Hybrid reinforcements—RHA-SiC (55–75% hardness), RHA-B₄C (40–60% wear resistance), RHA-CNT/graphene (25–40% fracture toughness), and RHA-graphite (10–25% friction reduction)—overcome monolithic RHA brittleness. In cementitious applications, 10–20% RHA replacement of Portland cement enhances long-term strength, reduces chloride penetration by 30–50%, and achieves 15–30% theoretical CO₂ reduction. Emerging AI/ML approaches (ANN, SVR, random forest, XGBoost-SHAP) achieve predictive accuracy of R ≈ 0.94–0.99 for mechanical and tribological properties. Critical barriers to industrial deployment include lack of standardized RHA characterization, limited pilot-scale validation, and scarce life-cycle assessment data. A prioritized roadmap addresses standardization, interface engineering databases, pilot demonstrators, AI-ready data infrastructure, and alignment with circular economy principles and ASTM/ACI standards.

Infrastructure project appraisal is a critical function of public investment management, especially in developing economies where fiscal discipline and institutional capacity are under pressure. This study analyzes the institutional mechanisms of appraisal, focusing on the Development Project Proposal (DPP) system and the role of the Project Evaluation Committee (PEC) as instruments of governance and accountability. The paper identifies recurring challenges such as optimistic costing, weak feasibility studies, and overlapping project scopes by using a qualitative institutional process analysis method. It also highlights the corrective role of appraisal deliberations in safeguarding fiscal credibility and infrastructure quality. The findings emphasize the need to strengthen upstream project preparation, set technical appraisal expertise, and institutionalize feedback loops. Beyond the specific national context, the study contributes to the literature on infrastructure policy by demonstrating how appraisal committees function as essential gatekeepers for sustainable public investment in developing-country contexts.

Land degradation threatens food security and biodiversity conservation affecting ecosystem services and the well-being of the population. Therefore, this study aimed to assess the spatial and temporal dynamics of land degradation and restoration in Niger using the indicator 15.3.1 of the Sustainable Development Goal (SDG). The assessment was conducted using the Trends.Earth plugin for a baseline period (2001–2015) and a reporting period (2016–2022). The results indicate that improvement is predominantly within Niger’s Great Green Wall (GGW). This reflects extensive land restoration initiatives aimed at combating desertification. Additionally, land productivity doubled between the baseline (14%) and the reporting period (28%). Although soil organic carbon declined slightly in bare lands (−2%), it increased in tree-covered areas, grasslands, croplands, and artificial surfaces by 2%, 4%, 18% and 50% respectively. The proportion of degraded land declined by half between the baseline (6.6%) and reporting period (3.3%). This highlights the effectiveness of the SDG 15.3.1 for evaluating land degradation. It also lays the basis for developing targeted conservation and sustainable land management strategies in Niger’s GGW.

This paper analyzes the drivers of public debt dynamics in Morocco using an accounting-based decomposition of the debt accumulation. The study quantifies the respective contributions of interest costs, economic growth, and the primary balance to changes in the debt-to-GDP ratio, and further decomposes the growth component into agricultural and non-agricultural sources. The results show that debt dynamics are primarily shaped by the interaction between interest payments and the denominator effect of growth, highlighting the dominant role of the interest–growth differential in mechanical debt accumulation. The primary balance emerges as a key policy-driven component, with years of fiscal slippage closely aligned with marked increases in the debt ratio. The sectoral decomposition indicates that the stabilizing effect of growth is structurally anchored in non-agricultural-activity, while agricultural growth is comparatively volatile. This paper provides a policy-oriented application of debt decomposition to a structurally dual emerging economy. By explicitly distinguishing agricultural and non-agricultural growth contributions, the analysis offers additional empirical insights into how growth composition shapes the stability of debt trajectories in climate-sensitive economies. The results suggest that aggregate growth should not be interpreted as a homogeneous stabilizer in dual economies, with important implications for fiscal sustainability assessments in emerging markets.