Synthesis of ethylene glycol esters of petroleum acids and their use as diesel additives

Optimum conditions for the synthesis of ethylene glycol esters of various fractions of petroleum acids are described; the possibility of using synthesized esters as diesel additives for improving the quality of fuels and increasing their service life is shown.     

Pythagorean Membership Grades,Complex Numbers,and Decision Making

We describe the idea of Pythagorean membership grades and the related idea of Pythagorean fuzzy subsets. We focus on the negation and its relationship to the Pythagorean theorem. We look at the basic set operations for the case of Pythagorean fuzzy subsets. A relationship is shown between Pythagorean membership grades and complex numbers. We specifically show that Pythagorean membership grades are a subclass of complex numbers called Π‐i numbers. We investigate operations that are closed under Π‐i numbers. We consider the problem of multicriteria decision making with satisfactions expressed as Pythagorean membership grades, Π‐i numbers. We look at the use of the geometric mean and ordered weighted geometric operator for aggregating criteria satisfaction.     

Thermal effectiveness of SAHs with diffusor-confusor heat receivers

The thermal effectiveness of solar air heaters (SAHs) is examined. The comparative analysis shows that the efficiency of the SAHs with the diffusor-confusor heat receiver significantly exceeds that of the SAHs with the flat-plate heat receiver.     

A formula relating the thermal conductivity of liquids to the sound velocity in them

On the basis of experimental data an analytical relationship is obtained between the thermal conductivity of liquids and sound velocity in them for wide temperature and pressure ranges. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 1, pp. 27–29, January–February, 1997.     

Optical properties of permanent gratings in liquid crystal doped with dye and carbon nanotube

Permanent gratings were written in planar nematic liquid crystal cells containing E7 doped with the azo dye Methyl Red and single-wall carbon nanotubes. An order parameter of S = 0.605 shows that the dye molecules align themselves very well with the liquid crystal’s director axis. A maximum absolute diffraction efficiency of 0.39% was found for cells doped only with 0.6% MR while a maximum of 2.6% was observed for cells doped with 0.6% MR and 0.002% CNTs. The data are consistent with permanent grating formation based on trans-cis photoisomerism of the dye molecules, followed by surface adsorption of the cis-isomer that leads to homeotropic alignment in the bright regions of the light illumination pattern. The robust permanent gratings were written without the aid of an external electric field and have remained stable for over 2 years.     

Effect of immobilized carbon nanoparticles on the activity of zeolites in the oxidative dehydrogenation of 4-vinylcyclohexene and ethylbenzene to styrene

The results of studies on the oxidative dehydrogenation of 4-vinylcyclohexene to ethylbenzene and styrene and ethylbenzene to styrene on nanocomposite systems prepared by the immobilization of carbon nanoparticles on the H forms of zeolites and the modification of the resulting samples with platinum, gallium, and gadolinium are given. The activities of these catalysts are compared, and the synergism of the action of zeolite and carbon nanoparticles under the conditions of dehydrogenation is established. The immobilization of carbon nanoparticles into zeolite matrices contributes to an increase in their activity and stability and also to a decrease in the reaction temperature. The high yields of 4-vinylcyclohexene and ethylbenzene dehydrogenation products are reached at 425 and 470°C, respectively.