The Determination of the Specific Heat of Heavy Mineral Oils

1920 ◽  
Vol 12 (9) ◽  
pp. 891-894 ◽  
Author(s):  
Herbert S. Bailey ◽  
Carlton B. Edwards
Author(s):  
Tobias Förster ◽  
Artur Blivernitz

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.


1883 ◽  
Vol 174 ◽  
pp. 601-613

I. Introductory. Ever since the discovery of glucinum by Vauquelin, in 1798, its atomic weight has been a disputed matter amongst chemists. Its discoverer considered that its oxide was a monoide, an opinion which was however strongly opposed by Berzelius, who wrote the oxide Gl 2 O 3 and the atomic weight 13⋅7 (O=16). The researches of Awdejew and Debrayt again turned the scale in favour of the earlier view, and as an atomic weight of 9⋅2 suited the properties of the metal in the tables of periodicy constructed by MM. Mendeleef and Lothar Meyer, this atomic weight has, up to quite recently, been generally accepted by chemists. As a welcome confirmation to this came a determination of the specific heat of the metal by Professor E. Reynolds, J who found that for its atomic heat to be near the normal number 6⋅0, its atomic weight must be 9⋅2 and not 13⋅8. Almost immediately afterwards a second determination of the specific heat was made by MM. Nilson and Petterson, who, however, obtained a result agreeing not with the lower atomic weight hut with the higher. The reasons for these conflicting opinions are to be found—first, in the anomalous position of glucinum among the elements; secondly, in the difficulties which surround the preparation of even small quantities of the free metal in a tolerably pure condition; and thirdly, in the fact that no volatile compound of glucinum is known of which the vapour density might be easily determined.


1982 ◽  
Vol 60 (14) ◽  
pp. 1853-1856 ◽  
Author(s):  
Eva I. Vargha-Butler ◽  
A. Wilhelm Neumann ◽  
Hassan A. Hamza

The specific heats of five polymers were determined by differential scanning calorimetry (DSC) in the temperature range of 300 to 360 K. The measurements were performed with polymers in the form of films, powders, and granules to clarify whether or not DSC specific heat values are dependent on the diminution of the sample. It was found that the specific heats for the bulk and powdered form of the polymer samples are indistinguishable within the error limits, justifying the determination of specific heats of powders by means of DSC.


In October, 1898, the author commenced experiments, having for their object the determination of the specific heat of superheated steam. At first an attempt was made to obtain this end by measuring the rise in temperature produced in a known quantity of steam by supplying a definite amount of heat in the form of electrical energy, but the experimental difficulties experienced in satisfactorily preventing radiation, in maintaining the rate of flow of steam uniform and in securing a steam supply sufficiently homogeneous and constant as to temperature, proved so great that the attempt on these lines was given up for a time, but returned to later. Then another method was adopted, that of allowing dry saturated steam to expand without doing external work, and observing the resulting change in temperature. This method had been used in preliminary experiments on this subject by Professor Ewing and Mr. Dunkerley, who found that the specific heat of superheated steam at atmospheric pressure, as deduced by this method from Regnault’s values of the "total heat,” was not a constant, as had been previously supposed, but increased with temperature.


1943 ◽  
Vol S5-XIII (7-9) ◽  
pp. 473-488
Author(s):  
Boris Brajnikov ◽  
Solange Duplaix

Abstract Describes the heavy mineral components of the sedimentary formations of the Paris basin, France, discusses problems relating to the determination of the provenance of the minerals, and concludes that the Central Massif may well have supplied the material of which the sedimentary deposits are formed.


1991 ◽  
Vol 74 (6) ◽  
pp. 968-973
Author(s):  
Aziz Geahchan ◽  
I Le Gren ◽  
Paul Chambon ◽  
Renee Chambon

Abstract An improved method has been developed for quantitative determination of poiynuciear aromatic hydrocarbons (PAHs) in pharmacopoeial paraffin and medicinal white oil samples. This new method combines 2 liquid-liquid partition and adsorption chromatography procedures with a 2-step purification on Sephadex LH 20 and liquid chromatography with fluorometric determination. Selective elution of PAHs results in absence of background fluorescence. The minimum detectable level ranges from 0.2 ppt for benzofluoranthene isomers to 200 ppt for acenaphthene. Recoveries of PAHs added at 7 ppm varied from 92.1 to 111.4%. When a variety of medicinal white oil samples were analyzed by this improved method, 27 PAHs were identified, including 11 suspected carcinogens. Their identities were confirmed by capillary gas chromatography.


Sign in / Sign up

Export Citation Format

Share Document