Finding appropriate shaking parameters is crucial in designing effective mechanical harvesters. The maximum fruit removal can be achieved when the machine operator properly adjusts the amplitude and frequency for shaking each tree. This review covers the progress in research and development over the past decades on using mechanical harvesters for nut trees, such as almonds, pistachios, walnuts, and hickories, with a specific focus on the natural frequency of individual trees. Furthermore, the reported values of shaking frequency and amplitude from previous studies were discussed and compared, along with frequency calculation approaches based on various shaking mechanisms. Additionally, other parameters, such as clamping force, height, and shaking amplitude, were investigated to determine optimal values for minimizing tree damage. This review emphasizes that the tree’s diameter, height, and canopy morphology should be the primary factors considered when estimating the optimal shaking frequency for nut trees. It also highlights that, to date, the shaking amplitude, frequency, and duration set by field managers or machine operators tend to remain consistent for all trees, which can limit harvesting efficiency. The findings suggest that selecting these parameters uniformly across all trees may not result in efficient fruit removal for individual trees. However, with the assistance of modern computing technology and its adaptation for in-field applications, it is feasible to determine the optimal shaking frequency for each tree mathematically. This approach can maximize fruit removal rates while minimizing tree damage. Finally, the review suggests that improving existing harvesting machines by incorporating better vibratory patterns could offer benefits such as enhanced productivity, reduced labor costs, and decreased permanent tree damage.

In this study, thermal management strategies aimed at enhancing freshwater production in portable double-slope solar stills specifically designed for water-scarce regions, prioritizing lightweight and portable configurations are investigated. The findings reveal poly methyl methacrylate (PMMA) as the optimal slope cover material, achieving a freshwater output of 70 ml at the peak hours under a 40° tilt angle. Additionally, this configuration demonstrates the highest daily freshwater production, an impressive 275 ml per liter of brine water in the basin. This study significantly enhances system efficiency by implementing insulation, a metal absorber plate, and phase change materials (PCM) enhancements. This culminates in substantial improvements across scenarios: 40.5% (insulation), 36.6% (aluminum), 36.1% (PCM), and a remarkable 45.2% for the insulation/aluminum/PCM configuration. The combination design demonstrates an outstanding daily freshwater production of 385 ml, emphasizing the remarkable capabilities of these advanced thermal management strategies. These results underscore the transformative potential of advanced thermal management strategies, providing sustainable solutions for water-scarce regions. Moreover, the study addresses total dissolved solids (TDS) in distilled water, achieving an outstanding 95.8% reduction. Total dissolved solids levels drop from an initial 4970 ppm in saline water to below 200 ppm, aligning impeccably with WHO standards.