5-Acetyl[2.2]paracyclophane

The title compound 5-acetyltricyclo[8.2.2.24,7]hexa-deca-4,6,10,12,13,15-hexaene, C18H18O,is the first example of a mono-π-substituted [2.2]paracyclophane to be structurally characterized. The average bending angles are α = 13.2 and β = 9.9°. The distance between the \u27bottoms\u27 of the practically parallel boat-like benzene nuclei is 3.098(2) Å. The π conjugation between the acetyl group and the substituted benzene cycle is negligible (rotation angle ca 45°) because of steric hindrance

Energy efficiency challenge of waxy oil production by electric submersible pumps

In this paper the solid wax formation in two live oils of the Samara region fields on five operating pressures with different contents of high molecular substances were examined. For both oil samples a linear relation between wax appearance temperature and pressure was obtained. The study showed the inevitable transition of wax from the liquid phase to solid in the examined live oils under downhole conditions. This fact indicates a high probability of complications during well operations of these oilfields. If measures are not put in place to prevent the deposit formation in wells, there is a chance of complete blockage of tubing and flowlines by wax. These problems will lead to decrease in well flowrates to their shutdown, thereby increasing the operation costs to remove deposits and capital expenditures of oil production. Evaluation of the conditions for the wax precipitation in oil wells will allow to develop technology of prevention and remediation of previously formed organic deposits. The potential solid wax formation depth of both wells for minimum well flowrate of 20 m3 per day are calculated. The technology of continuous injection wax inhibitor in designed depth where formation of solid wax has not been observed yet is proposed

Influence of Primary Cosmic Radiation Mass Composition on the Estimation of Eas Energy

At the Yakutsk EAS array E_em is determined by using measurements of EAS Cherenkov light flux and charged particle flux. It is known from calculations that these characteristics depend on a sort of primary particle and, therefore, the estimation of E_em depends on a primary particle mass. In the work the dependence of the E_em/E_0 ratio on the energy is given and experimental data are compared with calculations by the QGSJET model. The calculations have been carried out for the primary proton and iron nucleus. The average calculated meaning of the value of E_em/E_0 ratio (between the proton and iron nucleus) within experimental errors is in agreement with experimental data that doesnt contradict to the mixed mass composition of primary cosmic radiation.Comment: 19th European Cosmic Ray Symposium. Aug 30 - Sep 3 2004, Florence, Italy. 3 pages, 1 figure. Subbmitted for publication in International Journal of Modern Physics

Muons with E_th >= 1 Gev and Mass Composition in the Energy Range 10^{18}-10^{20} ev Observed by Yakutsk Eas Array

The ratio of the muon flux density to charged particle flux density at distances of 300 and 600 m from the shower axis (\rhom(300)/\rhos(300) and \rhom(600)/\rhos(600)) is measured. In addition, the energy dependence of \rhom(1000) is analysed for showers with energies above $10^{18}$ eV. A comparison between the experimental data and calculations performed with the QGSJET model is given for the cases of primary proton, iron nucleus and gamma- ray. We conclude that the showers with \E\ge3\times10^{18} eV can be formed by light nuclei with a pronounced fraction of protons and helium nuclei. It is not excluded however that a small part of showers with energies above $10^{19}$ eV could be initiated by primary gamma-rays.Comment: 19th European Cosmic Ray Symposium, Aug 30 - Sep 3 2004, Florence, Italy. 3 pages, 1 figure. Submitted for publication in International Journal of Modern Physics

Fluctuations of Xmax and Primary Particle Mass Composition in the Range of Energy 5 10^{17} - 3 10^{19} ev by Yakutsk Data

The experimental distributions of \Xmax obtained with the Yakutsk EAS array at fixed energies of $5 \times10^{17}$, $1\times10^{18}$ and $5\times10^{18}$ eV are analysed. A recent version of the QGSJET model is used as a tool of our analysis. In the framework of this model, the most adequate mass composition of primary particles satisfying the experimental data on \Xmax is selected.Comment: 19th European Cosmic Ray Symposium, Aug 30 - Sep 3 2004, Florence, Italy. 3 pages, 1 figure. Submitted for publication in International Journal of Modern Physics

Structure of 3-(3,5-Dimethylpiperidino)-\u3cem\u3eN\u3c/em\u3e-(\u3cem\u3ep\u3c/em\u3e-Chlorophenyl)Succinimide

In the title molecule, 3-(3,5-dimethylpiperidino )-1-(4-chlorophenyl)-2,5-pyrrolidinedione (1), the N-(p-chlorophenyl) substituent is rotated by 68.8° relative to the succinimide plane. The piperidinyl ring has a chair conformation with all substituents in equatorial positions; the conformation around the piperidino-succinimide C--N bond is staggered