The low Young's modulus of biological particles results in their large deformation against the AFM probe forces; therefore, it is necessary to study the contact mechanics of bioparticles in order to predict their mechanical behaviors. This paper specifically deals with the contact mechanics of DNA nanoparticles with spherical and cylindrical shapes during manipulation. In previous studies, ...

Nanoindentation technology has proven to be an effective method to investigate the viscoelastic properties of biological cells. The experimental data obtained by nanoindentation are frequently interpreted by Hertz contact model. However, in order to validate Hertz contact model, some studies assume that cells have infinite thickness which does not necessarily represent the real situation. In th...

This is a preliminary version of lecture notes based on a 6 hour course given at the workshop Dynamics Beyond Uniform Hyperbolicity held in Provo, Utah June 2017. The goal of this course is two-fold. First we will present a number of tools and results in the smooth ergodic theory of actions of higher-rank abelian groups including Lyapunov exponents, metric entropy, and the relationship between ...

We measure the time change of the contact force F(t) during the impact between very soft gel balls and a rigid substrate. For low-impact velocities Vi, F(t) is single-peak functions as intuitively expected; and the relation between Vi and the peak value Fm [of F(t)] obeys the prediction of the standard theory for the impact in the linear elastic regime (i.e., the Hertz theory). On the other han...

An approximate theory for the scattering of an incident plane P wave into tube waves in a fluid-filled borehole drilled through two homogeneous half-spaces is proposed in this paper. This theory is in excellent agreement with the zero frequency formulation (White, 1983) for frequencies below hundreds of Hertz (in the range of conventional crosshole or VSP experiments) and flnite difference simu...

As a key component for transmitting electrical signals, the contact performance of connectors is directly affected by closing amount socket. It urgent to explore relationship between resistance and cylindrical groove electric connectors, as well range when their comprehensive optimal in vibration environments. Based on Hertz theory, long- short-axis parameters elliptical surface were obtained u...

The mechanical calculation model of rotary-vertical (RV) reducer is established on the basis considering displacement and stiffness. Without manufacturing error, parameters RV are input into solved by MATLAB software. Comparing solution results with analysis based Hertz contact theory, error within a reasonable range, which verifies reliability model. errors high-precision measuring instrument ...