Increase in Selectivity of Toluene Disproportionation and in <Emphasis Type="Italic">p</Emphasis>-Xylene Yield by Optimization of Zeolite Microporous Structure

The possibility of increasing the yield of target products and para-selectivity of toluene disproportionation on modified zeolites by optimization of their microporous structure was studied.     

Aromatization of butane over zirconium-containing and zinc-zirconia-zeolite catalysts

Comparative researches were conducted of zinc-, zirconia, and zinc-zirconia-ziolite catalysts for n-butane aromatization.     

On two definitions of a narrow operator on Köthe–Bochner spaces

It is already known that the Cesàro matrices of orders one and two are coposinormal operators on \(\ell ^2\). Here it is shown that the Cesàro matrices of all orders are coposinormal; the proof employs posinormality, achieved by means of a diagonal interrupter, and makes use of the Zeilberger’s algorithm and computational assistance by Maple?.     

Investigation of the effect of an electrical field on the mechanical strength of polystyrene film

The effect of an electric field on the time dependence of the mechanical strength of a polystyrene (PS) film is investigated at different values of voltage and duration of exposure. It is found that at first the strength of the PS film drops with exposure to the electric field and then slowly increases.Mekhanika Polimerov, Vol. 1, No. 6, pp. 78–84, 1965     

Elastic waveguides: history and the state of the art. II

In this paper, the normal modes of an elastic rectangular waveguide are analyzed. We retrace the key aspects of the almost 150-year history of this problem. Using the superposition method, we have obtained an analytical solution of the problem for four types of symmetry of the wave field. In addition, we have established important differences of the dispersion characteristics of normal modes in a rectangle from the Rayleigh–Lamb modes for an infinite plate and the Pochhammer–Chree modes for a cylinder. We give also an estimate of a series of approximate theories for a rectangular waveguide.

The numerical interpretation of the results of analysis is however necessary, and it is a degree of perfection which it would be very important to give to every application of analysis to the natural sciences. So long as it is not obtained, the solutions may be said to remain incomplete and useless, and the truth which it is proposed to discover is no less hidden in the formulas of analysis than it was in the physical problem itself.

                             J. Fourier [28, Sec. 13]

     

Effect of electrical discharges on the mechanical strength and molecular weight of polystyrene film

Electrically aged polystyrene film was examined to determine the effect of voltage, aging time, and nature of the medium on the mechanical strength and molecular weight. It was established that the changes in the mechanical strength and molecular weight of the film always correspond.Mekhanika Polimerov, Vol. 4, No. 1, pp. 59–63, 1968     

Conversion of Straight-Run Naphtha to C5−C6 Alkanes on Co(Ni)/HZSM–5/SO 4 2- —ZrO2 Composite Catalysts

Russian Journal of Applied Chemistry - The conversion of straight-run naphtha on composite catalytic systems containing HZSM-5 zeolite modified with 0.4 wt % Co or Ni and 15% SZ (10% SO 4 2-...     

Mass-spectrometric an EPR studies of methane interaction with Re?Al?O oxide catalysts

The effect of oxidative-reductive pretreatment of Re–Al–O catalysts on their activity in methane aromatization has been established. Paramagnetic centers have been identified and their contribution to the conversion of methane into benzene over these catalyst is discussed.

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- Re–Al–O . .