Kidney has a hierarchy of nephrons on the vascular arteriole tree consisting of nephron groups that interact with neighbourhoods. The kidney modeling approach for the pressure Dynamics is complex in mathematical and simulation models for paired and impaired nephrons. CA rules have been developed for multi nephron kidney model from individual nephron CA rules using cumulative algorithm based on additive cellular automata and modular arithmetic. The global emergent properties obtained from CA rules depict the pressure Dynamics of the multi-scaled nephron network mode up to ten lakh nephrons, clearly illustrating the nephron’s behaviour that has been captured from the experimental analysis. Regular oscillation as normotensive behaviour and irregular oscillations as hypertensive behaviour have been observed in 30000 and 1000000 nephron network models for different cases. The chaotic oscillations have been observed in the 30000-nephron kidney which leads to chronic kidney disease. Studying the causes and effects of renal diseases due to impairment of nephrons using CA kidney models leads to improvement in the early diagnosis and treatment.

In the present work, the Dynamics of a single spherical gas bubble surrounded by a rheopectic fluid obeying the Quemada model is numerically investigated while the bubble undergoes oscillatory motion due to acoustic forcing. The generalized form of the Rayleigh–Plesset equation has been used for studying bubble Dynamics in Quemada fluids. The integro-differential equation representing the Dynamics of the bubble is solved numerically using the finite-element method (FEM) and also the Gauss–Laguerre quadrature (GLQ) method. The effect of rheopexy number (Rx) and viscosity ratio (ξ) are then investigated over a wide range of working parameters. Numerical results show that the rheopectic behavior of the fluid surrounding the bubble can dramatically affect the bubble Dynamics. It is predicted that for highly anti-thixotropic fluids, harmonics are affected so much so that the bubble may exhibit chaotic behavior. For instance, at Rx = 0. 001 and ξ = 1/81, a one-micron-sized bubble may attain a size almost 30 times of its initial size. The general conclusion is that, in sonography, microbubbles dispersed in rheopectic fluids may indeed be considered as a potent ultrasound contrast agent provided that the fluid is just moderately anti-thixotropic otherwise its chaotic response might damage the adjacent tissues.

This study was an attempt to analyze the dynamic reaction of the exchange market pressure (EMP) to different states of the foreign exchange market and inflation in the Iranian economy during 1988: 4-2017: 4. To this end, the EMP index was calculated using Edwards’ s (2002) and Kumah’ s (2007) formulae. By considering inflation as the threshold variable and using Threshold Vector Autoregressive (TVAR) model, the results showed that lagged variables had no significant effects on EMP in a low inflation regime, but inflation had significant effects on EMP in a high inflation regime. The results of using the Markov Switching Vector Autoregressive (MS-VAR) model showed that in EMP and INF equations, the autoregressive coefficients in all lags and in both regimes were significant; this emphasizes the stability of the estimated VAR model. Based on the results of the MS-VAR equations, the results of the Granger Causality Test showed that when the EMP switched to a high regime, the inflation would have a significant impact on the EMP, but in the regimes where the EMP was at a low level, the inflation was not the cause of the EMP. EMP in low inflation regimes could also affect inflation while EMP was not the cause of inflation in high inflation regimes. Therefore, the policymakers should note that increasing EMP, even in low inflation regimes, can lead to pressure on prices. On the other hand, an increase in the foreign reserves causes the EMP to switch to a high regime; then, the inflationary pressures at any level of the inflation rate can exacerbate the exchange market pressure, and policymakers would be unable to control the currency market. Thus, if the EMP is controlled, the effects of inflation on the EMP will be discontinued, and this is a key point for policymakers.

This study investigates the evolution of bubble shape within a square area filled with blood. The accuracy of the numerical solution is validated using Laplace's problem and the free-rising of the bubble. The analysis is conducted in two dimensions and in a transient manner. The effects of ultrasound waves are applied as a function of pressure on the boundaries of the solution domain. Results show that applying a linearly increasing pressure on the computational domain boundaries causes a reduction in bubble radius. Furthermore, it is observed that assuming the air inside the bubble behaves as an ideal gas, leads to more pronounced changes in bubble radius compared to constant density assumptions. Oscillatory pressure distributions on the external boundaries result in corresponding oscillations in bubble radius. These fluctuations in bubble size could be utilized to exert tension on the walls of blood clots, ultimately aiding in their dissolution. The most intensive bubble size fluctuations occur in the frequency of 1 (MHz). Additionally, the disproportionate changes in bubble radius with pressure variations are attributed to the hysteresis phenomenon.