No abstract

This work presents a developed zero-dimensional cardiovascular (CV) system model, based on an electrical analogy, with a detailed compartmental description of the heart and the main vascular circulation which is able to simulate normal and diseased conditions of CV system, especially the stenosis valvular aortic. To know the effect of each parameter on hemodynamics, the number of parameters is increased by adding more segments. The developed model consists of 14 compartments. The results show that the severity of aortic stenosis (AS) effect varies with the effective orifice area and the mean pressure gradient for the case of no AS; the effective orifice area is 4[Formula: see text]cm2 and the mean pressure gradient is 0[Formula: see text]mmHg, while for the case of mild AS, the effective orifice area is 1.5[Formula: see text]cm2 and the mean pressure gradient is 27.24[Formula: see text]mmHg. For the case of moderate AS, the effective orifice area is 1.0[Formula: see text]cm2 and the mean pressure gradient is 44.68[Formula: see text]mmHg. For the case of the severe AS, the effective orifice area is 0.61[Formula: see text]cm2 and the mean pressure gradient is 77.51[Formula: see text]mmHg. It is found that the developed model can estimate an accurate value of the effective orifice area for any value of mean pressure gradient in AS. The results obtained for the CV system under normal and diseased conditions show a good agreement compared to published results.

The surface areas of the materials are generally the most vulnerable parts since they are directly exposed to different stresses such as wear, fatigue, and corrosion. On the other hand, the successive impact of the droplets finds numerous applications in additive manufacturing technologies such as 3D printing and liquid metal projection. The lamella state formed by the impact and spreading of the first particle represents the target for the second; however, its molten state or fragmented state, bouncing or a slide, interacts thermally and dynamically to allow or not allow stacking. The deposition, deformation, and solidification of the droplets are the constituent steps of the process which determine the final result, as the topography of the substrate not only conditions the mechanical adhesion of the drop to the substrate but also affects the wettability of the surfaces. The objective of this work was to model by numerical simulation the impact of successive and simultaneous droplets with solidification and simultaneous deformation in the presence of an oxide layer on the substrate, which presents different topography, in order to fix the knowledge on the behavior of the impact, the spreading, or the splashing with solidification. However, a peak diameter greater than 5% of the particle diameter causes the formation of concave roughness which directly infects the mechanical adhering and subsequently the formation of an ordinary lamella.