This paper investigates the application of nanofluids in lithium-ion battery (LIB) thermal management through a comprehensive review of thermal management system (TMS) development. The review focuses on systems incorporating both phase change materials (PCMs) and nanofluid technologies as solutions for managing heat generation and thermal hazards in LIBs. It demonstrates that traditional cooling techniques, such as air and liquid cooling, are less effective than nanofluids. These colloidal suspensions of nanoparticles (e.g. Al2O3, CuO, TiO2, AgO, as well as carbon-based nanomaterials) in base fluids enhance both thermal conductivity and convective heat transfer performance. The review demonstrats that using Al2O3-water nanofluids with a 2% volume fraction can reduce peak temperatures by 1.2°C, while hybrid nanofluids containing Al2O3-CuO can reduce temperatures by up to 54.23% at a 0.5% concentration. When PCMs are combined with nanofluids to form hybrid systems, maximum temperature reduction of up to 19.5% has been observed. These hybrid systems also contribute to greater thermal uniformity and delayed temperature increases. However, challenges such as nanoparticle stability, increased pressure drops, and environmental and economic concerns remain significant obstacles. This review concludes that TMSs using nanofluids in conjunction with PCMs within optimised channel designs show promising potential for enhancing LIB performance, though further research is needed to overcome the associated barriers.

This study presents a comprehensive investigation into recent advancements in pyramid solar stills (PSS), focusing on how internal and external modifications have enhanced both performance and sustainability. The research critically examines the limitations of conventional solar stills in providing clean water and proposes innovative solutions to improve their productivity. Internal improvements like the integration of phase change materials (PCMs), Nanoparticles (e.g., TiO2 and CNT-water Nanofluids), and energy storage materials (e.g., paraffin wax and quartz rock), meaningfully improve desalination output. PCM integration alone enhances water productivity by 35 to 101.5%, while Nanoparticle application assures an efficiency gains ranging between 6.1 to 54.4%. External modifications such as the integration of solar collectors, reflectors, and forced condensation systems, has increased water productivity. Statistically, the with water yield increases to 194% with a thermal efficiency up to 62.4%. Hybrid systems, that integrate multiple modifications, establish the greatest performance enhancements, delivering up to a 166% productivity growth when PCMs and reflectors are utilised in tandem. The results highlight that optimised PSS, developed through multidisciplinary approaches, offer a potential, sustainable, and cost-effective solution for freshwater production. However, a number of barriers linked to component integration and large-scale applications remain. More importantly, the associated findings of this review have stated a foundational framework to advance the design and operation of solar desalination technologies.

People in urban areas (such as streets, parks, semi-open and enclosed spaces) are exposed to varying microclimatic conditions. These conditions change depending on environmental characteristics and directly affect individuals’ bioclimatic comfort levels. The lack of climate-responsive urban planning exposes inhabitants to uncomfortable thermal stress. Establishing climate-sensitive thermal comfort conditions at the micro scale is therefore essential for creating more livable urban environments. In hot-arid climates, kabaltıs, roofed passages integrated into the street network, are among the spatial elements that influence pedestrian thermal comfort. However, there is limited knowledge in the literature regarding the thermal performance of these shaded structures, which provide both protection from solar radiation and shelter from rain and wind. This study aims to reveal the impact of kabaltıs, as traditional urban elements in hot-arid regions, on bioclimatic comfort, and to contribute to the development of climate-responsive urban design strategies. Due to the scarcity of research on the thermal performance of kabaltıs, the findings of this study provide new insights into climate-adaptive design solutions within traditional street networks and serve as a guide for urban planning practices. The research was conducted in the historical district of Diyarbakır Suriçi, focusing on six kabaltıs and their surrounding streets located in the Ziya Gökalp, Abdaldede, and Süleyman Nazif neighborhoods. At a total of 19 measurement points, air temperature, relative humidity, and wind speed were recorded over the course of one year. Using the RayMan Pro software, Physiological Equivalent Temperature (PET) values were calculated, and Sky View Factor (SVF) values were determined for comparative analysis. The results indicate that the studied streets and kabaltıs were exposed to varying degrees of heat and cold stress throughout the year. Shaded zones and kabaltıs exhibited lower air temperature and PET values compared to other points. In this hot-arid setting, the presence of covered, shaded areas was found to be effective in reducing solar exposure and lowering thermal stress during summer months. The measurements further revealed that urban geometry, particularly building height and street width, influenced solar radiation access and wind speed, thereby affecting PET values. In addition, no direct correlation was observed between SVF and PET, highlighting the need to consider other parameters when assessing bioclimatic comfort.

In hot climate regions, the direct impact of solar radiation on building surfaces, including heat absorption and storage, negatively impacts outdoor comfort and the living conditions of urban residents. This study investigates the impact of urban street geometry on building surface temperatures in a hot and dry climate, focusing on the traditional Suriçi district of Diyarbakır. Measurements were conducted at 25 locations throughout the year along streets with varying sky view factor (SVF) values and within vaulted covered passages (kabaltıs). In the study, a Testo 410-2 anemometer was used to measure air temperature and a thermal camera was used to measure surface temperature. The results show smaller daily surface temperature amplitudes in regions with lower SVF values and in kabaltıs with an SVF value of 0. Measured surface temperatures reached as high as 58.8 °C at high SVF locations, while they remained around 30 °C in shaded kabaltıs. The findings indicate that street geometry parameters such as building height, spacing, and orientation significantly influence microclimate conditions. Differences of up to 15-20 °C were observed between shaded kabaltıs surface temperatures and other surface temperatures at measurement points where the SVF value was close to 1. Reducing SVF through design strategies such as the use of kabaltıs and planting trees can improve outdoor thermal comfort in hot climates.

This study reviews recent advances in using nanofluids to enhance double‐pipe heat exchanger (DPHE) efficiency. The reviewexamines several types of nanofluids, that is, water‐based graphene oxide and CuO–water nanofluids, assessing their effec-tiveness under different operating conditions, including inlet temperature and nanoparticle volume concentration. Experi-mental findings demonstrate that the inclusion of nanofluids can lead to notable improvements in thermal performance factorsand thermal exchange ratios, primarily due to enhanced thermal conductivity. The review shows that optimizing flow rateper unit volume and nanoparticle concentration can significantly reduce pressure drop while achieving a peak heat transfercoefficient. Furthermore, minimizing the concentration level would ensure efficient thermal performance with manageablepressure losses. Statistically, titanium dioxide nanofluids of 0.5% concentration can enhance thermal rates by 14.8%, while 115%improvement in heat transfer coefficients is ascertained using 0.6% concentration of multi‐walled carbon nanotubes. Using ironoxide nanofluids can rise heat transfer rates by 41.29%, with negligible pressure drop after exposure to a magnetic field.Furthermore, hybrid nanofluids of aluminum oxide–titanium dioxide can introduce 84% enhancement in thermal performance,emphasizing their potential to optimize heat transfer in DPHE. However, further investigation is required particularly with theuse of advanced surfactants to further enhance the thermal conductivity of DPHEs, and the need for long‐term stabilityassessments and cost–benefit analyses to support the industrial implementation of nanofluid‐based thermal systems.

Low freshwater productivity and poor thermal efficiency remain key limitations of conventional single-slope solar stills. In this study, porous absorbing materials are investigated as passive performance-enhancement strategies for small-scale solar desalination. A combined experimental and numerical analysis was conducted on a traditional solar still (TSS) and two modified configurations incorporating melamine sponge (MSSS) and pumice stone (VPSSS), operated under real climatic conditions in Karbala, Iraq. The results demonstrate that the MSSS achieved the highest daily freshwater yield of 1347 mL/day, corresponding to a 56.9% increase compared with the TSS, alongside an average thermal efficiency of 49.3%. The VPSSS produced 1055 mL/day, representing a 22.9% improvement and a thermal efficiency of 38.2%. Economic analysis indicates that, under optimal operating conditions, the MSSS reduced the water production cost to 0.07569 USD/L with a payback period of approximately 2.5 years. The energy payback period ranged from 0.55 to 0.86 years, whereas the exergy recovery period remained considerably longer (28–35 years), highlighting inherent thermodynamic limitations. In addition, the MSSS configuration achieved an annual CO2 emission reduction of approximately 1612 kg, corresponding to a cost saving of 17.36 USD. Overall, the findings suggest that porous absorbing materials, particularly melamine sponge, offer an effective and economically feasible approach for enhancing solar still performance in arid and remote regions.

The challenge of electricity consumption is one of the most pressing Global issues today. Air-conditioning systems represent a major part of this consumption, and their impact is even more visible in hot-desert climate. A practical approach to mitigate this problem is to pre-cooled ambient air before it enters the outdoor unit, which not only improves system performance. In this experimental study, a split-type air conditioner of 1.5-ton capacity was tested under the summer conditions of Karbala city, Iraq. Direct evaporative cooling technique was adopted using a 100 mm thick cellulose pad, positioned 55 cm away from the outdoor condenser to allow better air-moisture mixing. Comparative measurements were carried out between the conventional units and the modified one. The results showed a reduction in power consumption by up to 24.56% and an increase in coefficient of performance by nearly 37.47%. From an economic point of view, the analysis revealed that the maximum saving in annual electricity cost was about USD 20.45, while the life-cycle saving ranged between USD 220 and USD 365. The payback-time of the initial investment was estimated around 3 years which indicates a relatively short recovery time. Such findings provide a meaningful signal toward adapting environmentally friendly strategies.

The electrical performance of photovoltaic (PV) modules is strongly dependent on operating temperature, with elevated cell temperatures causing significant efficiency losses. Passive air-cooled heat sinks offer a sustainable alternative to active cooling systems; however, identifying fin geometries that maximise heat dissipation remains a key challenge. This study numerically investigates the thermal and electrical performance of PV panels integrated with leaf vein–inspired fins in four configurations: parallel-I (PAR-I), parallel-II (PAR-II), pinnate (PIN), and reticulate (RET). Three-dimensional CFD simulations were conducted using ANSYS Fluent to evaluate the effects of fin spacing (0.02–0.07 m), height (0.02–0.07 m), and thickness (0.002–0.007 m). All leaf vein fin configurations significantly enhanced heat dissipation compared with the uncooled PV panel. Among the investigated designs, the RET configuration provided the most effective cooling due to its branched geometry. The optimal RET geometry, 0.03 m spacing, 0.05 m height, and 0.006 m thickness, achieved a maximum temperature reduction of approximately 33.6 °C relative to the uncooled panel and increased PV efficiency from 12.04% to 14.19%, corresponding to a relative improvement of about 18%. These findings demonstrate that leaf vein–inspired fin architectures provide an effective, low-cost, and maintenance-free solution for passive thermal management of PV systems operating in hot climates. The associated efficiency gains also imply potential economic savings and reduced CO2 emissions under hot-climate operating conditions.

The tilt angle of phase change material (PCM) enclosures plays a decisive yet often underestimated role in governing heat transfer pathways during melting and solidification. By modifying the strength and structure of buoyancy-driven flow, enclosure orientation shifts the balance between natural convection and conduction, thereby reshaping solid–liquid interface evolution, temperature distribution, and overall thermal performance. This review synthesizes findings many experimental and numerical studies covering simple cavities, fin-enhanced designs, metal foam composites, and nano-enhanced PCMs. Results show that horizontal orientations generally accelerate melting through stronger convection and Rayleigh–Bénard cell formation, whereas vertical configurations promote slower but more uniform heat penetration. Optimal tilt angles vary by system type—typically around 60° for many rectangular enclosures, lower angles for finned systems, and minimal sensitivity in conduction-dominated metal-foam composites. Nanoparticles strengthen conduction but may dampen convection, altering tilt-dependent behavior. A cross-configuration mechanistic synthesis reveals that tilt-angle effects arise from universal principles: buoyancy strength, boundary layer development, and interface morphology. The review concludes with practical guidance for designing orientation-optimized PCM systems for thermal energy storage, photovoltaic cooling, and HVAC applications and highlights research needs for emerging geometries and multifunctional composites.

Metal-air batteries (MABs) are gaining attention as next-generation energy storage systems because of their lightweight designs, high theoretical energy densities, and potential cost-effectiveness. This paper employs the integrative methods of systematic and bibliometric reviews to chart the development, landscape, and trend of MAB research for portable power. Literature coverage over the past 20 years reflects an accelerating and highly collaborative research community, showing an annual publication growth rate of 19.13 % and an international co-authorship rate of 26.72 %. According to the analyses, factorial and keyword analyses both flagged zinc–air batteries as the most studied subclass since they are highly accessible, cheap, and eco-friendly. The study found flexible electronics, hydrogels, gel polymer electrolytes, density functional theory, and new alloys as emerging themes that reflect a shift from fundamental reaction research to application-driven materials and device design, especially for wearable and flexible technology. The categorization of themes also reflects two cross-cutting directions of research: multifunctional catalysts, solid/quasi-solid electrolytes, and flexible architecture as the mainstream phenomenon, and polyelectrolyte/gel polymer electrolytes as the turning but unexploited field. The review identified ample opportunities to combine high-performing catalysts with hybrid electrolytes and advanced zinc anodes, apply computational screening together with operando characterization, and foster increased collaboration between developed and developing economies. Together, these strategies can accelerate translation from laboratory-scale proof-of-concept prototypes to high-energy and scalable metal–air batteries mechanically compliant for next-generation portable and wearable power systems.