Esters of sucrose and tall oil fatty acids

The possibility of preparing monoesters derived from sucrose and tall oil fatty acids was examined.     

On the possible discovery of intercalated carbonate anions via the analysis of 13C NMR spectra of graphite-like carbon materials

Analysis of ¹³C NMR spectra of graphite-like carbon materials shows that pyrolytic carbon, being a part of carbon-carbon composites, contains carbonate ions that are probably intercalated between the graphite-like layers of composites as in the case of layered double hydroxides.     

Rings Associated with Finite Projective Planes and Their Isomorphisms

We announce an explicit form of the standard basis for the 2-extended ring associated with the cellular ring generated by the incidence graph of a finite projective plane. This enables us to give the first example of a distance-regular graph that satisfies the 6-condition and is not distance-transitive. One more consequence of the result obtained is that the cellular rings of any two projective planes of the same order are 2-isomorphic. This implies that, if for some order there exist at least two nonisomorphic and nondual to each other projective planes, then the separability number of the cellular ring of any projective plane of this order is greater than or equal to 3 and, moreover, it is equal to 3 for a Galois plane. Bibliography: 9 titles.     

New Measurement of the π0 radiative decay width

High precision measurements of the differential cross sections for π0 photoproduction at forward angles for two nuclei, 12C and 208Pb, have been performed for incident photon energies of 4.9-5.5 GeV to extract the π0→γγ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The π0→γγ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is Γ(π0→γγ)=7.82±0.14(stat)±0.17(syst) eV. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current Particle Data Group average of this fundamental quantity, and it is consistent with current theoretical predictions.     

Production of Biodiesel Fuel by Transesterification of Triglycerides in the Presence of Sodium Pyrophosphate

The possibility of using anhydrous sodium pyrophosphate and its decahydrate in transesterification of triacyl glycerides (with sunflower and rapeseed oils as examples) with methanol to obtain biodiesel fuel was examined. As shown by gas-chromatographic analysis, at the vegetable oil to methanol ratio of 1: 12, temperature of 65°C, reaction time of 2 h, and catalyst concentration of no less than 6 wt %, the maximal yield of methyl esters of fatty acids (biodiesel) was 93 and 69% when using Na₄P₂O₇ and Na₄P₂O₇·10H₂O, respectively. The catalytic effect of sodium pyrophosphate in the transesterification of triacyl glycerides was attributed to its methanolysis with the formation of sodium methylate. Water present in sodium pyrophosphate decahydrate causes hydrolysis of the formed sodium methylate; therefore, the yield of methyl esters of fatty acids is lower than with anhydrous pyrophosphate. Anhydrous sodium pyrophosphate can be used repeatedly no less than five times without significant decrease in the yield of methyl esters of fatty acids. Sodium pyrophosphate can be recommended for use in transesterification with other esters and alcohols.

     

Determination of the Composition of Glasses Produced at the Lava Factories by X-Ray Fluorescence Spectrometry and Optical Spectroscopy

Journal of Analytical Chemistry - Compositions of Russian glasses of the 18th century manufactured at state-own factories have almost not been investigated so far. This work presents the results of...     

p-Adic Multiresolution Analysis and Wavelet Frames

We study p-adic multiresolution analyses (MRAs). A complete characterization of test functions generating an MRA (scaling functions) is given. We prove that only 1-periodic test functions may be taken as orthogonal scaling functions and that all such scaling functions generate the Haar MRA. We also suggest a method for constructing sets of wavelet functions and prove that any set of wavelet functions generates a p-adic wavelet frame.     

Investigation of the Diastomerism of Compounds with a Long-Chain Tether between the Stereogenic Centers

Russian Journal of Organic Chemistry - The NMR spectra of several heterocyclic compounds synthesized at Omsk universities revealed manifestation of a diasteomerism at a large (up to fifteen bonds)...     

Three-dimensional few-cycle optical pulses in an array of carbon nanotubes inside a magnetic field

The behavior of three-dimensional few-cycle optical pulses, propagating in a system of carbon nanotubes inside an external magnetic field applied parallel to the nanotube axes and perpendicular to the direction of pulse propagation, is studied. The evolution of the electromagnetic field is classically derived using Maxwell’s equations.