Distal flow of polymethylmethacrylate (PMMA) bone cement during insertion of the femoral implant results in reduced pressure and cement-bone interdigitation (Markolf, Amstutz, 1976). Insertion of femoral cement plugs in the intramedullary canal to prevent distal flow of PMMA cement in total hip replacement during cementing of femoral prostheses is well accepted and has become current practice (...

Portland cement for high-temperature geothermal applications typically includes 35 to 40 percent crystalline quartz by weight of cement (BWOC) to avoid strength retrogression, which is defined as an increase in permeability and a decrease in compressive strength. Also, because of the reactivity of Portland cement at elevated temperatures, relatively expensive cement-hydration retarders are requ...

We investigate the performance of graphene oxide (GO) in improving mechanical properties of cement composites. A polycarboxylate superplasticizer was used to improve the dispersion of GO flakes in the cement. The mechanical strength of graphene-cement nanocomposites containing 0.1-2 wt% GO and 0.5 wt% superplasticizer was measured and compared with that of cement prepared without GO. We found t...

BACKGROUND Pedicle screws with PMMA cement augmentation have been shown to significantly improve the fixation strength in a severely osteoporotic spine. However, the efficacy of screw fixation for different cement augmentation techniques, namely solid screws with retrograde cement pre-filling versus cannulated screws with cement injection through perforation, remains unknown. This study aimed t...

This paper concerns the scanning, and grading of kiln-dried hardwood lumber. A prototype system is described that uses laser sources and a video camera to scan boards. The system automatically detects defects and wane, grades the boards, and then searches for higher value boards within the original board. The goal is to derive maximum commercial value based on current market lumber prices. This...

This article reports the findings into patterns of governance on nonprofit boards in Australia. The research surveys 118 boards, upon which serve a total of 1405 directors. The findings indicate that nonprofit boards can mimic some aspects of a shareholder approach to governance. But nonprofit boards, in the main, indicate priorities and activities of a stakeholder approach to governance. The f...

OBJECTIVE Medical specialty boards have a Maintenance of Certification (MOC) paradigm whose intention is to ensure high-quality patient care. How the patient experience is affected by physician MOC enrollment/participation is unknown. Our goal was to determine if patient experience is associated with physician board certification and MOC status. METHODS We analyzed physician experience and MO...

The past feds months ha:;e s4e1.I :~apiij.b i5XWiXC3 ciCCe;2tar.Ce Of the concept of recertification 3s a c:esira.i3le approaah to demonstration --T---of physicians accoczbxity. ?Gost of tr;e twenty-two specialty boards have expressed formal approval of voluntary, periodic reexamination for the purpose of assurirlg clinical competence. One board requires periodic rece.rtificatior:. Four boards ...

Using mostly elementary considerations, we find out who wins the game of Domineering on all rectangular boards of width 2, 3, 5, and 7. We obtain bounds on other boards as well, and prove the existence of polynomial-time strategies for playing on all boards of width 2, 3, 4, 5, 7, 9, and 11. We also comment briefly on toroidal and cylindrical boards.