This paper proposes the computation and assessment of optimal tilt and azimuth angles for a receiving surface, using a mathematical model developed at the University of Tomsk, Russia. The model was validated and analyzed for the Nuevo León State, Northeast Mexico, utilizing a set of metrics, comparing against satellite data from NASA. A point of interest in the city of Monterrey was analyzed to identify orientation patterns throughout the year for an optimal solar energy gathering. The aim is providing the best orientation tilt angles for photovoltaic or solar thermal panels without tracking systems. In addition, this analysis is proposed as a tool to achieve optimal performance in sustainable urban development in the region. Based on the findings, a set of optimal tilt and azimuth surface angles are proposed for the analyzed coordinates. The aim is to identify the optimal performance to obtain the maximum solar irradiation possible over the year for solar projects in the region. The results show that the model can be used as a tool to accelerate decision making in the design of solar harvesting surfaces and allows the design of discrete tracking systems with an increase in solar energy harvesting above 5% annually.

Intelligent suspension systems assist in decreasing the impact of road disturbances on passenger comfort, and its design requires a mathematical analysis that includes the elements of the suspension and the passenger's vertical dynamics. The contribution of this research is to merge a 4 degrees-of-freedom (DOF) Boileau-Rakheja biodynamic passenger model with a 3-DOF suspension model to generate more accurate representations of the displacements and accelerations of the main passenger's masses. Moreover, the contribution is complemented with a Skyhook controller in a semi-active 7-DOF one-quarter vehicle suspension to improve passenger comfort, and a case study presents tests in frequency and time domains. The analysis was conducted by establishing a regulatory closed-loop feedback control for a state-space system, simulating its behavior using MATLAB/Simulink, and comparing the results against specific performance criteria. The active suspension's frequency response showed a 40% reduction in the displacement transmissibility of the suspended masses at low frequencies (0-4 Hz), but exhibited a 2-10% increase in the rms acceleration at high frequencies (4-15 Hz). The herein results could be the base for further studies in the passenger comfort and road holding for one quarter, but also for half and full vehicle.