Determination of the total acid number (TAN) of used mineral oils in aviation engines by FTIR using regression models

[EN] Total acid number (TAN) has been considered an important indicator of the oil quality of used oils. TAN is determined by potentiometric titration, which is time-consuming and requires solvent. A more convenient approach to determine TAN is based on infrared (IR) spectral data and multivariate regression models. Predictive models for the determination of TAN using the IR data measured from ashless dispersant oils developed for aviation piston engines (SAE 50) have been developed. Different techniques, including Projection Pursuit Regression (PPR), Partial Least Square, Support Vector Machines, Linear Models and Random Forest (RF), have been used. The used methodology involved a five folder cross validation to derive the best model. Then a full error measure over the whole dataset was taken. A backward variable selection was used and 25 highly relevant variables were extracted. RF provided an acceptable modelling technology with grouped dataset predictions that allowed transformations to be performed that fitted the measured values. A hybrid method considering group of bands as features was used for modelling. An innovative mechanism for wider features selection based on genetic algorithm has been implemented. This method showed better performance than the results obtained using the other methodologies. RMSE and MAE values obtained in the validation were 0.759 and 0.359 for PPR model respectively.The authors would like to thank Roland Tones of the Universidad Metropolitana for his collaboration in oil sample processing. BLDR acknowledges financial support from the Venoco Company. The authors also thank the Universidad Politecnica de Madrid for granting access to the CESVIMA (http://www.cesvima.upm.es/) HPC infrastructure. We would also like to thank the author Beatriz Leal de Rivas (in memoriam), for her efforts to conform this team of researchers from different areas of expertise, and we want to dedicate this work to her loving memory.Leal De-Rivas, BC.; Vivancos, J.; Ordieres Meré, J.; Capuz-Rizo, SF. (2017). Determination of the total acid number (TAN) of used mineral oils in aviation engines by FTIR using regression models. Chemometrics and Intelligent Laboratory Systems. 160:32-39. doi:10.1016/j.chemolab.2016.10.015S323916

Exploiting Residue Curve Maps to Assess Thermodynamic Feasibility Boundaries under Uncertain Operating Conditions

The very first step of almost any separation process design procedure is the thermodynamic feasibility analysis. In the case of distillation, residue curve maps (RCMs) represent an essential tool to assess whether the separation is feasible or not. However, the analysis is generally carried out by referring to nominal operating conditions and product purities as specification. This means that, when process parameters are likely to undergo fluctuations, the prediction of the system response is not that obvious. An ABE/W (acetone−butanol−ethanol/water) mixture was then selected as a case study since it allows us to discuss several non-ideal thermodynamic behaviors and because of the renewed interest in biorefinery and sustainable processes during recent years. Residue curve mapping was then exploited to determine the thermodynamic feasibility range for multicomponent distillation processes as well as for distillation trains and process-intensified solutions taking into account both product purity and product recovery specifications. The final product of this study is a thorough procedure to determine the flexibility boundaries of feed and product compositions as well as an immediate and intuitive graphical representation from a binary standard distillation column to a complex multicomponent dividing wall column applicatio

ПЕРЕНАКОПЛЕНИЕ КАПИТАЛА В СССР. НЕУСВОЕННЫЙ УРОК И НЕПРЕОДОЛЕННЫЕ ПОСЛЕДСТВИЯ В ЭКОНОМИКЕ СОВРЕМЕННОЙ РОССИИ

Russia's economy is rooted in the national economy of the USSR, but because they can detect the same phenomenon. For example, in modern Russia there is such a negative phenomenon of loss of capital productivity, it was also observed in the USSR. So, the fundamental flaw of the Soviet system have not been overcome in today's Russia. This fundamental flaw – the phenomenon of absolute overaccumulation of capital, for which the conditions have developed since the first years of Soviet power. Action phenomenon is illustrated in the period after the second world war (great Patriotic war). The conclusion is that to overcome the systemic defect of the USSR in today's Russia, to exit the condition of absolute over-accumulation, will require fundamental socio-economic changes will be the abolition of wage nature of work.Экономика России уходит корнями в народное хозяйство СССР, а потому в них можно обнаружить одни и те же явления. Например, в современной России наблюдается такое негативное явление, как убыточная фондоотдача, оно так же наблюдалось и в СССР. Значит, фундаментальный недостаток советской системы не преодолен и в сегодняшней России. Этот фундаментальный порок – явление абсолютного перенакопления капитала, условия для которого сложились с первых лет Советской власти. Действия феномена проиллюстрированы на периоде после ВОВ (Великой Отечественной войны). Делается вывод, что для преодоления системного порока СССР в современной России, для выхода из состояния абсолютного перенакопления, потребуются фундаментальные социально-экономические изменения, которые будут заключаться в отмене наемного характера труда