A goal of this work is proposal and construction of simulation methods of haptic reproduction and interactive visualization of a beating heart in cardiovascular surgical training and education. The data for the beating heart model was obtained from ECG-gated 3D MRI of a normal volunteer. The elastic information was assumed as a uniform value with clinically experienced elasticity. Using a real-...

Direct electron imaging with sufficient time resolution is a powerful tool for visualizing the three-dimensional (3D) mechanical motion and resolving the four-dimensional (4D) trajectories of many different components of a nanomachine, e.g., a NEMS device. Here, we report a nanoscale nonchaotic motion of a nano- and microstructured NiTi shape memory alloy in 4D electron microscopy. A huge ampli...

This article deals with minimizing quadratic functions with a special form of quadratic constraints that arise in 3D contact problems of linear elasticity with isotropic friction [Haslinger, J., Kučera, R. and Dostál, Z., 2004, An algorithm for the numerical realization of 3D contact problems with Coulomb friction. Journal of Computational and Applied Mathematics, 164/165, 387–408.]. The propos...

Abstract We study how three-dimensional linearized elasticity for thin plates can be approximated by a two-dimensional projection. The classical approach using formal asymptotic expansions in powers of the thickness in the Hellinger-Reissner formulation, only provides error estimates in the H1 norm for the displacements, assuming at least L2 regularity for the applied forces, plus additional re...

The in vivo function and phenotype of ovarian follicle cells are determined by many factors. When these cells are removed from the in vivo microenvironment and grown in a 2D in vitro environment, the function of the follicular cells is difficult to preserve. A collagen hydrogel was used to examine the hormone and oocyte maturation of ovary follicles in a 3D culture system. Ovarian follicles fro...

A stochastic response of an elastic 3D half-space to random displacement excitations on the boundary plane is studied. We derive exact results for the case of white noise excitations which are then used to give convolution representations for the case of general finite correlation length fluctuations of displacements prescribed on the boundary. Solutions to this elasticity problem are random fi...

We fabricate grating-structured metallic microsprings with well-defined helical angles and diameters, which are self-rolled from strained nanomembranes patterned with gratings. The grating structures on the metal membrane, replicated from the imprinted polymer layer beneath, give rise to the controlled rolling direction after selective etching of the underlying sacrificial layer. The rolling di...

Computational algorithm for the solution of 2D and 3D dynamic problems of the Cosserat elasticity theory using multiprocessor computer systems is worked out. The algorithm is based on the two-cyclic splitting method with respect to the spatial variables in combination with the explicit monotone finite-difference ENO–scheme for solving 1D problems adapted for the calculation of discontinuities. ...

Many injection/production wells have been hydraulically fractured to enhance injectivity/productivity. Various engineering models for fracture geometry have been developed, which define the propagation of a fracture with time and wellbore treatment pressure. These models combine with elasticity, fluid flow, material balance, and propagation criterion/in-situ stresses. When this combination desc...

Many practical finite element models contain long slender regions and areas where the thickness is small in relation to the other dimensions. The slender regions are best modelled using 1D beam elements, while shell or plate type elements should be used to represent any areas consisting of thin walls. These reduced element types are much more efficient than using full 3D continuum elements (whi...