Search results

The aim of this paper is to study the effects of commercially available antioxidants on the oxidation stability of white mineral oils (paraffin oil).

Twelve commercially available antioxidants (Chimassorb 81, Tinuvin 326, Tinuvin 765, Tinuvin 571, Irganox L57, Irganox L109, Irganox L101, Irganox L115, Irganox L06, Irgafos 168, Naugard 445, BHT) were added to pharmaceutical and technical grade white mineral oils at 0.1%, 0.2%, 0.3%, 0.6% and 0.8% (w/w) concentrations. Light, heat and oxygen were applied to induce and accelerate oxidation. Total acid number, viscosity and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of the oils were measured to evaluate the performance of the antioxidant additives.

Results showed that combined heat and oxygen treatment was the most effective of the three conditions tested to cause oxidation. Based on the data, the best antioxidant additives to be used in white oils are decided to be Irganox L06 and Irganox L101. It was also found that the grade of oils (technical or pharma) did not create a significant difference in the results obtained.

To the best of the authors’ knowledge, this is the first study that reports effects of antioxidant addition on the oxidative properties of white mineral oils. This study advances knowledge of the behavior of white mineral oils under real atmosphere and provides comprehensive data on how the antioxidants affect the light, thermal, oxidative degradation of white mineral oils. The data presented also provide an insight to extend life expectancy of white mineral oils.

Manufacturing methods of white mineral oils are described, together with a summary of their major use areas. Recent toxicological studies using white mineral oils of various categories are covered. A summary of the current acceptable daily intake levels for such substances is included.

The objective of this paper is to measure the differences in heat transfer properties of refined hydrocarbon distillate fractions that are commonly used as base oils in aluminium sheet cold rolling applications and assess if the heat transfer coefficient (HTC) values for these oils can be predicted from their compositions. The composition and physical properties of these fluids affect their tribological behaviour by influencing hydrodynamic lubrication, wear debris removal and cooling.

A purpose-built test rig was used to measure HTCs for a wide range of hydrocarbon solvents used as aluminium cold rolling oils. The results are expressed in the form of the HTCs relative to those of 14- to 16-carbon-chain-length normal paraffins. Measured HTC values were compared to values calculated from oil compositions and from the thermal conductivities of compounds representing different classes of typical oil components.

There were significant differences between the heat transfer properties of various hydrocarbon solvents, and these differences could be estimated from their content of normal and simple iso-paraffins and heavily branched and cyclic hydrocarbons. The HTC of hydrocarbon mixtures increases with the increasing content of n-paraffinic compounds.

This paper shows how one can estimate the relative HTCs of oils of known compositions, based on the relative thermal conductivities of model compounds. This is relevant to prediction of cooling properties of aluminium cold rolling base oils.

The Presidential Address to the Liverpool Engineering Society by Mr. Farthing (the salient points of which are reproduced in this issue) has particular bearing upon lubrication and especially on young lubrication engineers. Mr. Farthing stressed the very wide field open to young engineers and the difficulties associated with training in order to cover as wide a field as may be necessary. It is usually so important to gain a wide knowledge before one can specialise and this is certainly the case with lubrication engineers. One cannot begin to fully appreciate the intricacies of a lubrication system with all its accessory components lubricating and guarding, for example, a large motive power plant or rolling mill, until one has more than a mere working knowledge of the plant itself, the duties it must perform, how it performs them and the snags that arise which might be overcome by correct lubrication. In view of the fact that lubrication systems are just as important in a textile mill as in a power station or a large brick works, the almost impossible‐to‐achieve‐range of knowledge that would simplify the work of a lubrication engineer is very obvious. Fortunately, lubricating principles apply to most cases and knowing how to apply one's knowledge from basic principles is the key to success in this difficult profession.

The subject of Horological Lubricants is one which has received very little attention in Lubrication literature. The erroneous tendency to consider that only machinery operating in very high temperatures under difficult conditions of pressure, loading or atmosphere, requires specialist lubrication care, is undoubtedly the reason for this. But the correct functioning of essential time pieces, as well as all small scientific instru‐ments, can be as vital as that of a large machine. The author had been interested in these matters for a number of years when Chief Chemist and Technical Director of Rocol Limited, in whose laboratories many of the advances described in this paper were first evolved and who have given permission for this paper to be published. This paper summarises much of the work carried out on Horological Lubricants over the past twenty‐five years.

Sales of industrial oils and fluids in the United States reached US $2.8 billion in 1986. However, due to falling crude oil prices in that year, and thus lower prices for several product catagories, the industrial lube market is actually down slightly in value from US $2.9 billion in 1985, according to a report recently released by Kline & Co, international petroleum industry consultants.

The purpose of this paper is to examine the effects of several structural shocks in oil prices on the Vietnamese economy and answer three key research questions: Is there a relationship between oil price shocks and macroeconomic indicators in Vietnam? How do different types of oil price impulses affect Vietnamese inflation and economic performance? To what extent do structural shocks in oil prices explain variations in Vietnam’s macroeconomic indicators?

Lower triangular Cholesky decomposition is performed on a short-term impact matrix in a two-block structural vector autoregressive model. The data set is defined monthly, from January 2000 to December 2021. The contributions of structural shocks in oil prices to the domestic variances are analysed using variance decomposition methods. In this study, both forecast error variance decomposition and historical decomposition are used.

The consequences of oil price fluctuations on Vietnamese output and inflation depend on different sources of oil price shocks. In comparison, oil supply shocks have an insignificant effect on both domestic industrial output and consumer price index inflation; however, positive shocks in aggregate and precautionary oil demands increase these domestic indicators substantially and sustainably. An analysis of variance decompositions reveals that supply-side oil shocks have very limited explanatory power for variations in domestic variables. Nevertheless, the contributions of unanticipated demand-side booms to domestic variations in the past and projected forecasts are considerable.

The findings from this research uncover potential risks for Vietnam’s economic prospects if the consequences of oil price shocks are not managed effectively.

Given the lack of economic sensitivity to supply-side oil shocks and the strong response to shifts in oil demands, greater pressure on the domestic economy is likely when Vietnam increases its dependence on oil imports.

We hear a lot about the dollar saving effected by our expanding refineries in this country, and these very great savings are mainly due to the refining of petrol and diesel fuels. But the saving effected from the refining of lubricating oils is also very considerable. The main object, and that taking first place in the programme of refinery expansion, has been the production of fuel oils but now that most of our largest oil refineries are in full production, work has been progressing with their lube‐oil plants, several of which are now coming on stream. Lube oils have a high average value, are used by every household and every industry and whilst representing only a very small part of the revenue of a large refinery, they are nevertheless a valuable part and just as vital to industry as fuel, in fact one is useless without the other.

Chester Street, Aston, Birmingham, 6. The ‘Donald’ Patent Barrel Lifter Truck and Stand, the three‐in‐one appliance. Barrels up to 7 cwts. lifted and transported by one man. ‘Donald’ Patent Barrel Lifter Stands for Oil Stores.