In the milestone of straggling to make water hydraulics more advantageous, the choice of coating polymer for water hydraulics valves plays an essential role in alleviating the impact of cavitation erosion and corrosion, and this is a critical task for designers. Fulfilling the appropriate selection, we conflicted properties that are vital for erosion and corrosion inhibitors, as well as the tribology in the sense of coefficient of friction. This article aimed to choose the best alternative polymer for coating on the selected substrate, that is, Cr₂O₃, Al₂O₃, T_i2O₃. By applying PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations), the best polymer obtained with an analyzed performance attribute is Polytetrafluoroethylene (PTFE) that comes up with higher outranking (0.5932052). A Molecular Dynamics (MD) simulation was conducted to identify the stronger bonding with the regards of the better cleave plane between Polytetrafluoroethylene (PTFE) and the selected substrate. Polytetrafluoroethylene (PTFE)/Al₂O₃ cleaved in (010) plane was observed to be the strongest bond in terms of binding energy (3188 kJ/mol) suitable for further studies.

Cavitation erosion and corrosion commonly occur on the surface of fluid dynamic system components, mostly water hydraulic valves, causing the failure of metal parts. Coating of polytetrafluoroethylene (PTFE) on Al₂O₃ (010) was created by varying the chain length of polytetrafluoroethylene. Calculations were conducted by molecular dynamic (MD) simulations. This study shows that the K10 and K20 chain lengths’ mechanical properties possess negative elastic, shear, and bulk modulus values. We have found that the K10 chain length composition shows the high results of binding energy and negative bulk modulus of 6267.16 kJ/mol and −3709.54 GPa, respectively. The K10 chain length was observed to possess a higher cohesive energy density (CED) and solubility parameter of (6.885 ± 0.00076) × 10⁹ J/m³ and (82.974 ± 0.005) (J/cm³)^0.5, respectively. It was also found that increasing the chain length contributes to decreasing the binding energy and solubility parameter of PTFE/Al₂O₃ (010) composition. These results are vital for overcoming the repetitive regime of high compressive strength of water microjets on the valves’ material surface. Improved values of the cohesive energy density and solubility parameters imply the water’s superior hydrophobic effect.

Tanzania’s hospitality sector faces persistent challenges in providing reliable and affordable hot water because of rising electricity tariffs, grid instability, and reliance on fossil fuel backup systems. Given the country’s high solar irradiance, hybrid photovoltaic (PV) and solar thermal (PV/T) systems are a promising option for increasing thermal energy reliability and reducing operational costs and environmental impacts. This review synthesizes global and regional studies on hybrid configurations that integrate photovoltaic electricity generation with solar thermal water heating technologies, focusing on their relevance to hotel operations in Tanzania. We describe system design approaches, control strategies, storage options, and reported operational outcomes, and we summarize performance ranges (notably reported solar fractions of roughly 60–80% in well-designed systems) and typical techno economic indicators. The evidence indicates that hybrid systems can substantially increase solar contribution to hot water loads and reduce grid dependence, but adoption in Tanzania is constrained by limited local performance data, a lack of standardized design practices, and insufficient techno economic evaluations tailored to local conditions. We conclude that hybrid PV/T systems show strong potential for commercial hot water use in Tanzania and recommend targeted field trials, standardized design guidelines, and context specific economic analyses to support wider deployment.