Lagrangian based mathematical modeling and experimental validation of a planar stabilized platform for mobile systems

Typical operating conditions for mobile sensor systems, and in particular mobile robots, exhibit a wide range of mechanical disturbances due their ego-motion. Sensor systems mounted on these mobile platforms often suffer to varying degrees from these disturbances. The quality of acquired data is degraded as a result. For instance, the quality of captured video frames from an onboard camera greatly depends on the angular velocity of the body on which the camera is mounted. Motion blur degradation results if large angular motions are present. In order to compensate for such disturbances, stabilization platforms are used. A common approach is measuring body movements using inertial sensors and attempting their cancellation with actuators and control systems. Design of high performance control systems often requires analytical system models. In this article, a planar stabilization platform is considered, to develop and study its kinematic and simple-to-complex dynamic model. The mathematical derivation of the model is presented with and without neglect of the actuator mass components as well as friction effects. This is followed by the comparative validation of these model alternatives against a realistic numerical model fitted to physical experimental data. The results demonstrate that the analytical model, in particular with the actuator mass and friction components included, provides a high degree of fit to the actual behavior

A Nonlinear Dynamic Strategy for Mathematical Modeling and Simulation of Stabilized Platform in Planar Motion in One Body and Three Bodies

Abstract Mathematical modeling and simulation of a head stabilization platform. The stabilization platform is capable of moving on the pitch degree of freedom. The platform is modeled in two different approaches; considering only the mass of the platform (One-body) and considering platform, actuating shaft and actuator masses (Three-Body)

Histological Evaluation of Wound Healing Effect of Topical Phenytoin on Rat Hard Palate Mucosa

Extension and duration of wound healing following periodontal surgery are very important. The aim of present study was histological evaluation of wound healing of topical phenytoin on rat hard palate mucosa. A total of 60 rats were randomly divided into four groups of 15(n=15). A standard 4×6 mm diameter wound was created on the hard oral palate of each rat. The control group were given an equal volume of normal saline. The group of phenytoin and chitosan gel received the topical gel of phenytoin and chitosan, respectively. The fourth group were received a dosage of 10mg phenytoin daily. Five rats each were sacrificed and all sections were examined for histologic changes by light microscopy. The mean number of neutrophils, fibroblasts, macrophages, epithelialization, and the density of collagen fibers were evaluated in each group. Data were analyzed using ANOVA and Kruskal-Wallis tests. The number of fibroblasts and the rate of epithelialization in the group of phenytoin gel were significantly higher on the 7th day than the control group (P <0.05). The density of collagen fibers on the 14th day was significantly higher in the group of phenytoin gel than the control group (P <0.05). It can be concluded that topical phenytoin to promote wound healing of rat hard palate

Posterior reversible encephalopathy syndrome in SARS‐CoV‐2 infection: A case report and review of literature

Abstract Consider PRES in SARS‐CoV‐2 infected patients who develop encephalopathy, seizures or impaired vision; especially if the disease is complicated by respiratory distress and need for mechanical ventilation