Advances in tribological testing of artificial joint biomaterials using multidirectional pin-on-disk testers.

The introduction of numerous formulations of Ultra-high molecular weight polyethylene (UHMWPE), which is widely used as a bearing material in orthopedic implants, necessitated screening of bearing couples to identify promising iterations for expensive joint simulations. Pin-on-disk (POD) testers capable of multidirectional sliding can correctly rank formulations of UHMWPE with respect to their predictive in vivo wear behavior. However, there are still uncertainties regarding POD test parameters for facilitating clinically relevant wear mechanisms of UHMWPE.

Laboratory SIP signatures associated with oxidation of disseminated metal sulfides.

Oxidation of metal sulfide minerals is responsible for the generation of acidic waters rich in sulfate and metals. When associated with the oxidation of sulfide ore mine waste deposits the resulting pore water is called acid mine drainage (AMD); AMD is a known environmental problem that affects surface and ground waters. Characterization of oxidation processes in-situ is challenging, particularly at the field scale.

Full-Scale investigation of the influence of flow equalization and prefermentation on nitrification.

This article presents the findings on the effects of flow equalization and prefermentation on nitrification in a full-scale municipal plant. Existing primary clarifiers in one process train were modified for diurnal flow equalization and for a low-rate volatile fatty acid production. The performance of the biological process was compared with the parallel reference process train operated with conventional primary clarification.