This study presents a combined enhancement approach to improve the thermal and electrical performance of a photovoltaic–thermal collector by utilizing a 50% TiO2–50% Fe3O4 hybrid nanofluid at 0.5% concentration and perforated twisted tape turbulators with different twist ratios. An experimental investigation was conducted to evaluate heat transfer effectiveness, energy efficiency, exergy efficiency, and hydraulic performance. The results indicate that a twist ratio of the two provides the best overall performance, achieving a heat transfer enhancement exceeding 67% compared to the baseline system. Maximum energy and exergy efficiencies of 82% and 30%, respectively, were obtained. These improvements are attributed to enhanced thermal conductivity and intensified fluid mixing. Although the proposed method increases pressure drop, the overall thermo-hydraulic performance remains favorable, as confirmed by the performance evaluation criterion. The findings demonstrate that the proposed configuration is an effective and practical solution for advanced photovoltaic–thermal applications.
Photovoltaic (PV) panel performance and efficiency are significantly affected by environmental conditions, such as elevated temperatures and dust accumulation, especially in hot, arid regions. These factors directly reduce energy output and limit system reliability, making their mitigation essential for sustainable PV operation. Generally, a 10°C rise in panel temperature causes a 5
The study assessed rare earth element (REE) pollution in Rawanduz River stream sediments in Iraq's Kurdistan Region. Twenty-seven stream sediment samples (> 80 mesh) were analyzed using Inductively Coupled Plasma Mass Spectrometry. Overall, REE concentrations were comparable to the Upper Continental Crust values, with light REE (LREE) dominating over middle and heavy REE, reflecting natural geological sources. Spatial patterns showed LREE enrichment with weak Eu and Ce anomalies in carbonate-dominated areas, while MREE enrichment and stronger anomalies occurred in zones possibly influenced by igneous and metamorphic lithologies, suggesting fractionation and sorting effects through weathering and hydrodynamic sorting. Geo-accumulation indices classified most sediments as unpolluted, with minor low-level enrichment in specific REE at certain districts. Factor analysis identified four main factors explaining 81.8
Investigation on thermal performance of nanofluid flat-plate solar collector in the severe hot climate. The investigation for experimentally test and numerical modeling is done with Baghdad, Iraq as a representative case. Three working fluids at 1 vol.
The performance of photovoltaic/thermal (PV/T) systems declines significantly under hot climatic conditions because rising cell temperatures reduce electrical conversion efficiency and limit the recovery of useful heat. This study aims to evaluate the effectiveness of CuO/water nanofluid cooling in improving PV/T performance under Iraqi climatic conditions and to assess the capability of machine-learning models to predict system efficiency. A three-dimensional CFD model was developed in ANSYS Fluent for a PV/T system operating under steady laminar flow, with CuO/water nanofluid concentrations ranging from 0.25 to 1 vol
