Disorders of HFP can follow indirect (Fig. 4) and direct (Figs. 5 and 6) acute traumas and chronic repetitive microtraumas, such as infrapatellar plica syndrome [5, 6, 7] or impingement syndrome [8, 9, 10, 11] (Figs. 7 and 8).
Three stages of surface crystallization were identified depending on the growth geometry: (1) impingement-free growth, (2) increasingly laterally-constrained transverse growth, and (3) interstitial growth.
We evaluated: (1) dry filtration for collecting C. psittaci from contaminated air using different samplers and membrane filters, (2) impingement into different liquid collection media by use of the AGI-30 impinger and the BioSampler and (3) impaction into newly designed C. psittaci media utilizing the MAS-100 aerosol impactor.
At 30° erodent impingement, all coated samples outperformed the uncoated substrate; whereas, for 90° impingement, only coatings deposited at low bias values (− 25 V, − 50 V, and − 100 V) and high Ti Cr ratios (> 2.4) outperformed the uncoated substrate.
In addition, the experimental observations suggest that small quantities of H2O impingement and dissociation may be exhibited in some specimen tips.
3. Impingement of the femoral neck at the acetabular shell or at osteophytes in the area, causing mechanical stresses at the finally dissociated interface.
The 90° impingement angle erosion testing resulted in fracturing of WC grains followed by eruption of binder matrix by interlinking of cracks originated from fractured WC grains.
From this analysis it is observed that the peak erosion rate occur at about 60° impingement angle at constant impact velocity (66 m/s), erodent size (450 μm), stand-off-distance (75 mm) and erodent temperature (60 °C) for all the composites.
Conforming to the minimization of erosive wear at desirability equal to 1: 4.67% by weight HNT composition, 0.9235 bar pressure, and 900 impingement angle, a wear rate of 0.0391x10-5g/g is found.
The worn-out surfaces revealed that the material was removed by micro-cutting and ploughing of CoCr matrix, leading to the loosening and pull-out of WC grains in case of 30° impingement angle erosion testing.
