Thermal analysis methods to study the reservoir bitumens

Journal of Thermal Analysis and Calorimetry - The bitumen-containing reservoir rocks taken from Devonian terrigenous formation of Romashkino and Bavly oil fields (Russia) were sampled and...     

Thermal and structural characterization of bitumen by modulated differential scanning calorimetry

Journal of Thermal Analysis and Calorimetry - This paper presents the results of investigation of model bitumens, prepared by mixing of individual fractions of bitumen (saturates, aromatics, waxes,...     

Compatibility of olefinic thermoelastoplastics with oxidized bitumens of various colloidal structures

The compatibility of oxidized bitumens of types I and III with blended olefinic thermoelastoplastics was studied by calorimetry, viscometry, and atomic-force microscopy. Improvement of process characteristics of modified products based on bitumens is asssociated with different mechanisms of formation of their structure.     

Large deflections and rigidity of a long cylindrical orthotropic glass-plastic panel subjected to intermittent-uniform loads

Large deflections and the stability of a long slanting orthotropic cylindrical panel, subjected to an external pressure uniformly distributed over a section of the panel width, are discussed. Relationships are used, taking into account lateral-shift deformation and normal stress _z. A closed-loop solution is obtained by means of generalized functions. A numerical evaluation has been made to assess the error of Kirchhoff's hypothesis. Similar solutions, taking into account the lateral-shift deformation are presented in [4, 5] for cases involving continuous uniform pressure and local linear loads.Kazan Physicotechnic Institute, Academy of Sciences of the USSR. Translated from Mekhanika Polimerov, No. 5, pp. 829–837, September–October, 1972.     

Phase composition of asphaltenes

The phase composition of asphaltenes taken from oils of Romashskino field (Russia) was studied with calorimetry. It was found that in asphaltenes there are ordered amorphous phases which break in the temperature ranges 70–130 and 130–170 °C. Polarization microscopy data show that the liquid crystal phase appears at temperatures from 180 to 190 °C. Moreover, it is shown that in asphaltenes the crystal phases of co-precipitated paraffinic hydrocarbons and salts can be present.     

Study of Organic Self-Assembled Nanosystems by Means of High-Frequency ESR/ENDOR: The Case of Oil Asphaltenes

An approach to investigate self-assembly of oil disperse systems based on high-field electron nuclear double resonance has been suggested. As exemplified by asphaltenes, the oil components most prone to self-assembly, the formation of planar rather than multilayer structures has been directly evidenced experimentally. The suggested method can be applied to elucidate the self-assembly mechanism in wide range of organic objects.     

Formation of new structural states in compressed BaTiO<Subscript>3</Subscript> nanopowders

The structural changes in BaTiO₃ nanocrystal powder and tablets have been probed via X-ray diffraction, scanning electron and transmission microscopy, and differential calorimetry after successive hightemperature annealing in air. It is shown that, beginning with the annealing temperature of 1200°C, significant amount of the Ba₂TiO₄ phase forms in the tablets together with the BaTiO₃ phase. This phase is equilibrium one; it practically vanishes when the annealing temperature decreases to 700–600°C; and this phase practically restored to the initial state when the annealing temperature is again increased to 1200°C. Annealing the powders causes no formation of new phases, but an increase in their crystallite sizes. A probable reason of the emergence of Ba₂TiO₄ phase in tablets and its absence in free powder is discussed, as well.