It is generally assumed that fingerprints improve the grip of primates, but the efficiency of their ridging will depend on the type of frictional behaviour the skin exhibits. Ridges would be effective at increasing friction for hard materials, but in a rubbery material they would reduce friction because they would reduce contact area. In this study we investigated the frictional performance of ...

Geckos can run rapidly on walls and ceilings, requiring high friction forces (on walls) and adhesion forces (on ceilings), with typical step intervals of approximately 20 ms. The rapid switching between gecko foot attachment and detachment is analyzed theoretically based on a tape model that incorporates the adhesion and friction forces originating from the van der Waals forces between the subm...

snake robots are hyper-redundant robots that are connected with one or two dof joints. they offer a number of potential advantages beyond the capabilities of most wheeled and legged robots. in this paper, kinematics and dynamics of a planar multi-link snake robot in worm-like locomotion on an inclined surface is investigated. in this locomotion, snake robot is able to move in the vertical plane...

laminar mixed convection of aluminium oxide (al2o3)–water nanofluid flow in an inclined annulus using a single-phase approach was numerically studied. constant heat flux boundary conditions were applied on the inner and outer walls. all the thermophysical properties of nanofluid, such as, viscosity, heat capacity, thermal conductivity, and thermal expansion coefficient, except density in the bo...

An edge tessellation of the plane is generated by the reflection of some polygon in its edges. We prove that a polygon generating an edge tessellation is exactly one of the following: An equilateral, 30-right, isoceles right, or 120-isoceles triangle, a rectangle, a 60-rhombus, a 60-90-120-kite, or a regular hexagon. The results in this paper were discovered by Millersville University students ...

Oysters are hypothesized to affect the shear strength of nearby surficial seafloor sediment as fragments oyster shells (shell hash) typically more angular relative sand particles alone, among other differences. Resistance shearing is well characterized by friction angle, which estimated in this study from vacuum triaxial laboratory and portable free-fall penetrometer field tests. Friction angle...

Abstract. We study a quadratic C0 interior penalty method for the displacement obstacle problem of Kirchhoff plates with general Dirichlet boundary conditions on general polygonal domains. Under the conditions that the obstacles are sufficiently smooth and separated from each other and the boundary displacement, we prove that the magnitudes of the errors in the energy norm and the L∞ norm are O...

Due to excessive heating, various physical mechanisms are less effective in engineering and modern technologies. The aligned electromagnetic field performs as insulation that absorbs the heat from surroundings, which is an essential feature contemporary technologies, decrease high temperatures. major goal of present investigation use magnetism perpendicular surface address this issue. Numerical...

Using a combination of ellipsometry and friction force microscopy, we study the reversible swelling, collapse and variation in friction properties of covalently bound poly(N-isopropylacrylamide) (PNIPAM) layers on silicon with different grafting densities in response to exposure to good solvents and co-nonsolvent mixtures. Changes in the thickness and segment density distribution of grafted fil...