The boundary value problem representing one time step of the primal formulation of elastoplasticity with positive hardening leads to a variational inequality of the second kind with some non-differentiable functional. This paper establishes an adaptive finite element algorithm for the solution of this variational inequality that yields the energy reduction and, up to higher order terms, the R−l...

In computed tomography (CT), reconstructions from conebeam (CB) data acquired with a polychromatic X-ray device show so called beam hardening artifacts. Beam hardening artifacts are highly undesirable for a medical diagnosis, because details in the reconstructed image are severely disturbed or completely lost. In this work, we demonstrate the significant reduction of beam hardening artifacts by...

This paper presents a mathematical characterization and analysis of beam-hardening artefacts in X-ray computed tomography (CT). In the field of dental and medical radiography, metal artefact reduction in CT is becoming increasingly important as artificial prostheses and metallic implants become more widespread in ageing populations. Metal artefacts are mainly caused by the beam-hardening of pol...

Replacing the Newtonian coupling G by −iG, the Schrödinger—Newton equation becomes “frictional”. Instead of the reversible Schrödinger—Newton equation, we advocate its frictional version to generate the set of pointer states for macroscopic quantum bodies.

A series of triaxial compression tests with different confining pressures were conducted for gravels, road surface milling materials, and surface–base mixtures to investigate the stress–strain relationships these three kinds materials. On basis analysis test results, strength deformation geocell-reinforced materials geocell-encased predicted compared those gravels via constitutive model geocell...

The administrators of a mission critical network usually have to worry about non-traditional threats, e.g., how to live with known, but unpatchable vul­ nerabilities, and how to improve the network’s resilience against potentially un­ known vulnerabilities. To this end, network hardening is a well known preven­ tive security solution that aims to improve network security by taking proactive act...

C60-terminated self-assembled monolayers (SAMs) were generated on the surface of Au(111) by the adsorption of unsymmetrical disul®des having saturated hydrocarbon backbone structures comprised of six (C-6) and eleven (C-11) carbon atoms. The formation of oriented monolayer ®lms from these adsorbates was con®rmed by ellipsometric thickness and contact angle measurements. The morphologies and fri...

Based on the assumption that fault slip dominates in stress relaxation brittle crust, Coulomb theory allows for crustal estimation with an empirical frictional coefficient. However, natural variability of friction and uncertainty exist Earth's crust. To address extent to which heterogeneous slips influence its evolution, we establish a quasi-static, 2D model represent fractured rock mass. The c...

Recent experiments on microscopic graphite mesas demonstrate reproducible high-speed microscale superlubricity, even under ambient conditions. Here, we explore the same phenomenon on the nanoscale, by studying a graphene flake sliding on a graphite substrate, using molecular dynamics. We show that superlubricity is punctuated by high-friction transients as the flake rotates through successive c...

The interplay between local mechanical strain energy and lateral frictional forces determines the shape of carbon nanotubes on substrates. In turn, because of its nanometer-size diameter, the shape of a carbon nanotube strongly influences its local electronic, chemical, and mechanical properties. Few, if any, methods exist for resolving the strain energy and static frictional forces along the l...