In this study, creeping motion as a natural locomotion mode and creeping motion of a snake-like robot on slope are studied. A snake like robot is designed by inspiring nature and snake's creeping motion, and is referred to as creeping robot. In this paper, a n+2 DOF creeping snake-like robot and its kinematics and dynamics are analyzed. Since in real situations a snake-like robot must pass through rough terrains and slopes, its motion on the slope is modeled and its equations of motion are obtained by Newton-Eulers method. Also, a software simulator is designed for simulation and analysis of a creeping robot. This software is used to find the optimum motion parameters of creeping robot locomotion on the slope with different angles. Optimization criterion in motion planning with efficient motion minimizes the frictional power loss. These results indicate a simple relationship between velocity, slope angles, and motion optimum parameters. The obtained efficient parameters are applicable to motion planning, controller design, and Neural Network training for the design of a creeping snake-like robot.    

Dip coating is a key technique in thin film fabrication, widely applied in protective coatings, and material surface engineering. The coating quality depends strongly on the fluid dynamics near substrate edges, where viscoelastic effects and inertial forces can lead to stress concentration and flow instabilities. A viscoelastic fluid model is formulated based on conservation of mass and momentum, with nonlinear governing equations solved using the Langlois recursive approach and the inverse method. Analytical solutions of the stream function provide insight into velocity fields, pressure distribution, and stress behavior near the substrate surface. Results show that stresses and pressure diverge near sharp substrate corners, which can compromise coating durability. Variations in the interface angle significantly alter stress distributions on both the substrate and free surface. Furthermore, inertial forces amplify fluid velocities in the corner region, directly influencing film thickness uniformity and mechanical performance of coated layers.

BACKGROUND AND AIM: The aim of this study was to evaluate the effect of topical phenytoin on creeping attachment.METHODS: In this pilot quasi-experimental study, 8 patients referring to Kerman School of Dentistry, Kerman, Iran with Miller class I or II gingival recessions were selected using convenient non-random sampling if they needed root coverage and met the study's inclusion criteria. The patients applied phenytoin mucoadhesive paste 1% on the surface of the deepithelialized gingiva of the tooth with gingival recession, twice a day for two months. Data was analyzed with paired t-test using SPSS version 17.RESULTS: According to our findings, the width of keratinized gingiva at the baseline was 3 mm, and after 2 months it increased to 3.1 mm. The mean baseline height and width of gingival recession were 1.9 mm and 3 mm, respectively and after 2 months they decreased to 1.8 mm and 2.9 mm accordingly. There was no significant difference in any of the aforementioned parameters before and after treatment (P>0.05).CONCLUSIONS: The results of this study showed that topical application of phenytoin mucoadhesive paste can not initiate and promote creeping attachment.

This paper concerns an analytical study of a steady axisymmetric uniform flow of an incompressible micropolar fluid past a permeable sphere that contains a solid sphere. The mathematical expression for the flow fields are obtained in terms of stream function by using modified Bessel’ s function and Gegenbauer function. No-slip condition, zero microrotation components, continuity of normal velocity which is equal to the filtration velocity on the surface of the sphere are used as boundary conditions. It is assumed that the fluid obeys Darcy law at the permeable surface. The internal and external drag force exerted by the fluid on the sphere, flow rate and the relevant quantities such as pressures, microrotation vectors have been calculated. It is observed that drag is greater for impermeable sphere as compared to permeable sphere. As permeability parameter increases the flow rate also increases rapidly. Various useful results are obtained and compared with the previous particular cases.

This paper undertakes a critical examination of Stokes’ law in its final form. The examination and insights of the viscosity principle substantiate grounds to suspect that the controlling dynamics are viscous shear rates across a geometry set by solid boundaries only. The examination sets grounds to conduct an analysis of the dynamics based on the viscosity principle alone and a flow model is derived. Based on the relationship between the pressure gradient and the shear forces as mandated by the viscosity principle the analysis suggests that the pressure gradient surrounding settling particles can be computed, is a single value and expands as required to mobilize a force equal to the driving force. In this context, the pressure gradient arises as a consequence of the contest between body forces in the fluid and the shear forces promoted by shear rates. The flow model suggests that Stokes’ law may be missing important information. An analysis is conducted for the settling velocity of non spherical particles based on the same dynamics and a mathematical solution is reached. The solution is in good agreement with published measured values and defines the influence of particle shape in settling phenomena

This paper derives a solution for the settling velocity of isolated coplanar aggregates of n identical spherical particles in creeping motion based on the Wall Shear-Pressure Gradient-Expansion model (WPE) previously derived by the author. The solution is reached by developing geometry-equilibrium mathematical constructs to decide on the dimensions of the free ambient expansions surrounding the aggregates to compute the entire velocity profile. A rational to decide on the orientation and stability of rotation is also proposed. The results compare well with the outcome of available theory and some relevant data sets.