Change in lubricity of oils with detergent additives in the course of aging

Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 10, pp. 13–16, October, 1992.     

Tribological,electrochemical, and spectral analysis of zinc dialkyldithiophosphates (ZDDP) of different thermal stabilities

The antiwear properties of five zinc dialkyldithiophosphates, which differed in thermal stability, were evaluated in a 4-ball machine by a preliminary wear track formation method. After testing the additives, the wear resistance of the films formed was measured by the increase in preliminary wear scar diameter over that of the additive-free oil. IR spectroscopy was then used to study the transformation products of additives after thermostatic testing at between 100 and 240°C on steel surfaces, where the interaction products were evaluated by electrode potential method. The interaction of the decomposition products of dithi-ophosphates with metal surfaces was found to be followed by a change in electrode potential. For the tested additives, a relationship is shown between antiwear effectiveness of the film on a friction track during tribological tests and the electrode potential value of the steel sample. Different parts of the relationship between the electrode potential and temperature relate to different stages of dithiophosphate decomposition measured by IR spectroscopy. It can be said that chemical modification of the steel surface which produces an improvement of antiwear properties, starts at the decomposition temperature of the dithiophosphate neutral salt.     

Certain relationships governing the selection of antifriction additives for lube oils

Chemistry and Technology of Fuels and Oils -     

Interrelation of efficiency and thermal stability of zinc dialkyldithiophosphates

Chemistry and Technology of Fuels and Oils -     

Hardware-efficient technique for minimizing startup transients in Direct Form II digital filters

A technique for generating initial startup conditions for Direct Form II digital filters is presented. Instead of discarding initial samples due to transients, the approach proposed here is to set the initial conditions of the filter so that they represent steady-state conditions of initial step excitation. The paper supplements the existing methods based on the assumptions that the previous input sequence is a white noise or mirrored signal. The approach is presented in both recursive and matrix notations. The performance is investigated in comparison with existing techniques. An illustrative example of image restoration and possible physical implementation is presented.     

Composite additive for GShZ gas condensate diesel fuel

K-1 composite additive to bring the quality of GShZ diesel fuel (DF) to the level of the requirements in GOST 305-82 for DF Z-45 and consequently to expand the area of its use was developed from domestic feedstock.Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 1, pp. 35 – 36, January – February, 2005.