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Demineralization of an oil shale by Bacillus circulans (“siliceous bacteria”)
(Elsevier, 1990)
Experiments are presented aimed at removing the silicates from an oil shale by a chemoorganoheterotrophic bacterium, Bacillus circulans. This process was expected to substitute the drastic HF-treatment in the kerogen ...
Metal-organic matter interactions in the formation of an oil shale deposit
(Elsevier, 1990)
An attempt was made to distinguish metal-organic matter interactions in two types of sulfate-reducing environments, mild (MR) and strong sulfate-reducing (SR), in the Aleksinac oil shale deposit (Oligocene-Miocene). Samples ...
Standard potential values of "cyanide-sensitive" silver iodide and silver sulphide ion-selective electrodes
(Analytica Chimica Acta, 1990)
It is shown that the equation for the potentials of semiconductive sulphide membranes given by Sato 25 years ago is valid also for the calculation of E0 values of "cyanide-sensitive" ion-selective electrodes. The only ...
Test of the validity of some kerogen models based on oxidative degradation
(Elsevier, 1990)
Molecular models of considerable complexity have been proposed recently for type I, II and III kerogens. Here, we describe the amount and type of carboxylic acids that one would expect to result from their multistep alkaline ...
13C N.M.R. spectra of some 5-substituted-3-isopropyl-6-methyl uracils
(Elsevier Science Publishers B.V., Amsterdam, 1990)
13C n.m.r. spectra of some 5-substituted-3-isopropyl-6-methyl uracils were determined in deuterated dimethyl sulfoxide (d6 - DMSO). The substituents are : H, Cl, Br, J, NO2, NH2, N(CH3)2, C6H5, C6H4-NO2-p and C6H4-NH2-p. ...
Thermoanalytical characterization of Aleksinac (Yugoslavia) oil shale kerogen
(Springer, 1990)
The chemical nature of the kerogen from Aleksinac (Yugoslavia) oil shale was studied by thermal analysis of a kerogen concentrate and the partially degraded kerogen concentrates obtained as intermediates in its stepwise ...
Properties of glassy carbon modified by immersing in metal cation solutions
(Vacuum, 1990)
Glassy carbon (GC) surfaces: 'as produced' in the carbonization process, abrased and oxidized were studied using AES, XPS and cyclic voltammetry. Evidence for the existence of an outer sheath formed during carbonization, ...
XPS and AES study of mixed layers of RuO2 and IrO2
(Elsevier, 1990)
The surface composition of RuO2+IrO2 mixed oxide layers (1-2 μm thick) deposited on titanium by thermal degradation of the corresponding chlorides in aqueous or isopropanol solutions has been investigated. A surface ...
Organic geochemical study of the "W" oil-gas field in the Yugoslav part of the Pannonian basin
(Organic Geochemistry, 1990)
The naphthenic crude oil from the "W" oil-gas field differs from almost all other, paraffinic base oils discovered until now in the Yugoslav part of the Pannonian basin. In order to explain this difference, some geological ...
Experimental determination of silicon pressure sensor diaphragm deflection
(Elsevier, 1990)
A method is presented for the accurate determination of the deflection of diaphragms commonly used for miniature piezoresistive and capacitive pressure sensors. The method utilizes a well-known apparatus for thin-film ...