OBJECTIVES Third-body wear is believed to be one trigger for adverse results with metal-on-metal (MOM) bearings. Impingement and subluxation may release metal particles from MOM replacements. We therefore challenged MOM bearings with relevant debris types of cobalt-chrome alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate bone cement (PMMA). METHODS Cement flakes (PMMA), CoCr a...

Men who have sex with men are an important yet marginalised population for HIV prevention in Africa. We conducted a two-phase study (individual qualitative interviews and a survey) of men who have sex with men, aged 18-34 years of age and living in Kisumu, Kenya. Approximately half (27/51) of survey respondents reported belonging to a support group. The odds of belonging to support groups were ...

Oil Chemical Research. USDA l-ARS-NCAUR. 1815 N. U;liuersity Street, Peoria, IL 61604, USA Accepted 8 October 1999 Compared to the lubricants made of petroleum, vegetable-based lubricants are much more biodegradable but inferior in many other technical characteristics. The basestock typically contributes to more than 80% of lubricant and must meet performance criteria in such aspects as cleanli...

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The object of this paper is to study the effects of lubricant film flow, pressurized and sheared between two parallel rough surfaces in sliding motion. The influence of microscopic surface roughness on lubricant film flow macroscopic behavior is described through five nondimensional parameters called flow factors. These macroscopic transport parameters are related to the local geometry of apert...

The products based on fossil oils are increasing with the concerns of environmental sectors and academics as well. In this era, there challenges to finding alternative resources replacing oil for different engineering applications. One is lubricant. Fossil lubricants have many industrial applications involve millions dollars each year in development due their huge needs. Accordingly satisfy nee...