Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

A new empirical correlation for estimating bubble point pressure using the genetic algorithm

Heidarian M., Karimnezhad M., Schaffie M., Ranjbar M.

Geology, Geophysics and Environment

2017

Vol. 43, no. 1

33--41

In this paper, a new and more accurate correlation to predict bubble point pressure (Pb) for Middle East crudes by using the genetic algorithm (GA) is attempted. For this purpose, a total of 286 data sets of different crude oils from Middle East reservoirs were used as training data for constructing the correlation. The general form of the correlation was found by several regressive examinations. To improve the correlation, the genetic algorithm was applied. To validate the correlation, 143 data sets of different crudes from Middle East reservoirs which were different from the training data were used as test data for calculating mean absolute relative error (MARE) and correlation coefficient (R2) between the predicted values from the proposed correlation and the experimental values. In addition, the MARE and R2 were calculated for previous correlation in the test data. The results show that the proposed correlation is more accurate than all of the previous correlations exclusively for Middle East crudes.

Synthesis, X-ray Crystal Structure and Solution Studies of Cu(II) Complexes of a Pyridine Containing Self-Assembling System

Ranjbar M., Taghavipur M., Aghabozorg H., Moghimi A., Jalali F., Shamsipur M.

Polish Journal of Chemistry

2002

Vol. 76 / nr 6

785-794

The complexation of a novel pyridine containing self-assembling system LH2, ([pyda_H2] [pydc] (pyda = 2,6-pyridinediamine and pydc_H2 = 2,6-pyridinedicarboxylic acid), with copper(II) acetate leads to the formation of an anionic self-assemble coordination compound, [(pyda_H)]2[Cu(pydc)2]_H2O. The crystal system is monoclinic with a space group P21/n and contains four molecules per unit cell. The unit cell dimensions are: a = 8.2567(19) A, b = 13.097(31) A, c = 23.384(6) A and _ = 94.685(5)_. The four carboxylate groups of two dianions are oriented in a flattened tetrahedral arrangement and the two dianionic units are almost perpendicular to each other. The axial N-Cu-N angle shows 2.65_ deviation from linearity. The complexation reactions in aqueous solution were investigated by potentiometric pH titrations and the equilibrium constants for all major complexes formed are described. The results are presented in the form of distribution diagrams revealing the concentration of individual complex species as a function of pH. The results revealed that, at pH = 4-5, the major complex species in solution is [(pyda_H)]2[Cu(pydc)2].