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This paper presents the experimental results carried out to evaluate wear prevention characteristics of a palm oil-based TMP (trimethylolpropane) ester using a four-ball machine for different regime of lubrication. The TMP ester is produced from palm oil, which is biodegradable and has high lubricity properties such as a higher flash point temperature and VI (viscosity index). Three different regimes of lubrications are investigated, which hydrodynamic, elasto hydrodynamic and boundary lubrications. Under these test conditions, the wear and friction characteristics of different TMP samples are measured and compared. For boundary lubrication, it is found that up to 3% addition of Palm oil-based TMP ester in OL (ordinary lubricant) decreases the maximum amount of WSD (wear scar diameter) and reduces (COF coefficient of friction) up to 30%. Highest amount of load (220 kg) carrying capacity was also found from the contamination of 3% TMP. For hydrodynamic lubrication, addition of 7% of TMP reduces the friction up to 50%. It is well known that mechanical efficiency of machinery component increases with decreasing COF. The results of this investigation will be used to develop new and efficient lubricant to substitute the petroleumbased lubricant partially for automotive engine application.

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Productive, spreading infection of peripheral blood lymphocytes (PBL) with human immunodeficiency virus type 1 (HIV-1) requires the viral protein Vif. To study the requirement for vif in this system, we infected PBL with a phenotypically complemented HIV-1 clone mutated in vif. Progeny virus was produced which was noninfectious in PBL but replicated in SupT1 cells. Analysis of metabolically labeled proteins of sedimentable extracellular particles made in PBL by radioimmunoprecipitation with either serum from a patient with AIDS or a monoclonal antibody reactive with HIV-1 Gag proteins revealed that vif-negative but not wild-type particles carry higher levels of p55, p41, and p38 Gag-specific proteins compared with those of p24. Similar results were obtained with sucrose-purified virions. Our data indicate that vif plays a role in Gag protein processing or in incorporation of processed Gag products into mature virions. The presence of unprocessed precursor Gag polyprotein (Pr55 gag) and other Gag processing intermediates in PBL-derived vif-negative extracellular particles may contribute to the reduced infectivity of this virus.