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Gergesova M.,University of Ljubljana | Saprunov I.,United Research and Development Center | Emri I.,University of Ljubljana | Emri I.,Institute for Sustainable Innovative Technologies
Rheologica Acta | Year: 2016

The closed-form shifting (CFS) algorithm is a simple mathematical methodology which determines the unique solution in the process of constructing master curves at selected reference temperature and pressure conditions. In a previous paper, the CFS algorithm has been fully described for monotonically increasing or monotonically decreasing functions only. This paper presents detailed steps of the generalized CFS methodology for non-monotonic functions, like the loss tangent. Performing shifting on the loss tangent, which does not require vertical shifting, is particularly important for materials which require vertical adjustment of dynamic viscoelastic functions, i.e., loss and storage moduli. Thus, based on horizontal shifting of the loss tangent, the CFS-based procedure of consecutive horizontal-vertical superposition for the storage modulus is proposed and analyzed. The analysis is done on the example of two synthetically generated non-monotonic tan delta segments and corresponding storage modulus segments in respect to different experimental parameters. It has been shown that the error brought by the shifting method into non-monotonic loss tangent and storage modulus master curves is twice smaller than the corresponding experimental noise level. © 2016 Springer-Verlag Berlin Heidelberg Source


Arutyunov I.A.,United Research and Development Center | Kulik A.V.,United Research and Development Center | Potapova S.N.,United Research and Development Center | Svetikov D.V.,United Research and Development Center | And 2 more authors.
Neftyanoe Khozyaystvo - Oil Industry | Year: 2016

The article is devoted to production of synthetic base stock of environmentally friendly drilling fluids. The Influence of Hβ and HY zeolites types and modules on alpha-olefins conversion and product composition of ethylene with hexane-1 cooligomerization was studied. The most active catalyst in cooligomerization process was HY (30) zeolite which possessed higher specific surface area compared with H (25) as well as higher acid sites concentration and higher total acidity values. It was shown that running of ethylene with hexane-1 cooligomerization process at the presence of mentioned above catalysts led to products obtaining. These products can be used as synthetic component of hydrocarbon based drilling fluids used for offshore drilling. Source


Kashin E.V.,United Research and Development Center | Shabalina T.N.,United Research and Development Center | Maslov I.A.,United Research and Development Center | Antonov S.A.,United Research and Development Center | And 3 more authors.
Neftyanoe Khozyaystvo - Oil Industry | Year: 2016

Infrastructure and equipment development of the Russian Arctic region requires to apply lubricants efficient in extremely low temperatures. The aim of this paper is to study the choice of crude, catalyst and determining technological factors of process for producing low -pour point base with pour point under -60 °C. Expansion of vacuum gas oil hydrocracking processes allows to involve the residues of such a process to the production of low -pour point oils. Hydrocracking residues and their fractions containing C12-C30 hydrocarbons with the absence of aromatic and sulfur-containing hydrocarbons provide producing low -pour point oils with excellent low temperature properties. Conducting hydroisomerization process under the platinum catalyst based on ZSM-5 zeolite at temperature of 280-300 °C, pressure of 3-6 MPa and applying hydrocracking residue fractions boiling at a temperature not higher than 440 °C as a crude, allows to produce oil with a pour point under -60 °C and a high yield. It is found that the platinum-containing catalyst based on zeolite ZSM-23 has a higher selectivity to hydroisomerization of crude comprising C30+ chain length hydrocarbons. © Copyright 2016. Source

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