Catalytic Materials Based on Hydrotalcite-Like Aluminum,Magnesium, Nickel,and Cobalt Hydroxides for Partial Oxidation and Dry Reforming of Methane to Synthesis Gas

Partial oxidation of methane and dry methane reforming to synthesis gas in the presence of catalysts based on hydrotalcite-like hydroxo salts [AlMg₂Ni _x Co _y (OH)_6.08][(NO₃) _n H₂O], where x = 0, 0.02, 0.04 and y = 0, 0.02, 0.04 with a total Ni and/or Co content of no more than 2 wt % have been first studied. It has been shown that the Ni-containing catalysts provide a synthesis gas yield of 90 and 97% in the case of partial oxidation and dry reforming of methane, respectively; in the presence of these catalysts, a trace amount of carbon nanotubes is formed; the catalyst sample containing both nickel and cobalt does not lead to the formation of any carbon nanotubes during dry reforming of methane.     

Preparation of alkylaromatic hydrocarbons on high-silicon zeolite-containing catalysts

Translated from Khimiya i Tekhnologiya Toplivi Masel, No. 3, pp. 20–23, March, 1992.     

Anomalous dependences of the diode barrier capacitance on bias voltage and temperature

Capacitances of a Schottky barrier and p ⁺-n junction whose n-type regions contain shallow donors and deep acceptors with levels in the upper part of the energy gap have been calculated. The capacitance was represented as two series capacitances of the near-contact region containing only donor impurity ions and of the intermediate layer at the interface between the space-charge region and the diode base, with account of the free-carrier concentration and its dependence on the potential. It was found that the capacitance of the intermediate layer heavily depends on temperature and may increase with the bias voltage. The calculated capacitancevoltage characteristics of the barrier capacitance are in agreement with experimental data and even describe the nonmonotonic dependences of the capacitance on the bias voltage.     

Can Modern Molecular Modeling Methods Help Find the Area of Potential Vulnerability of Flaviviruses?

Flaviviruses are single-stranded RNA viruses that have emerged in recent decades and infect up to 400 million people annually, causing a variety of potentially severe pathophysiological processes including hepatitis, encephalitis, hemorrhagic fever, tissues and capillaries damage. The Flaviviridae family is represented by four genera comprising 89 known virus species. There are no effective therapies available against many pathogenic flaviviruses. One of the promising strategies for flavivirus infections prevention and therapy is the use of neutralizing antibodies (NAb) that can disable the virus particles from infecting the host cells. The envelope protein (E protein) of flaviviruses is a three-domain structure that mediates the fusion of viral and host membranes delivering the infectious material. We previously developed and characterized 10H10 mAb which interacts with the E protein of the tick-borne encephalitis virus (TBEV) and many other flaviviruses’ E proteins. The aim of this work was to analyze the structure of E protein binding sites recognized by the 10H10 antibody, which is reactive with different flavivirus species. Here, we present experimental data and 3D modeling indicating that the 10H10 antibody recognizes the amino acid sequence between the two cysteines C92-C116 of the fusion loop (FL) region of flaviviruses’ E proteins. Overall, our results indicate that the antibody-antigen complex can form a rigid or dynamic structure that provides antibody cross reactivity and efficient interaction with the fusion loop of E protein.     

Non-elastic models of interaction of an impactor and an Uflyand–Mindlin Plate

This paper is devoted to the mathematical modeling of the low velocity impact of a solid body upon a thin elastic isotropic plate whose dynamic behavior is described by wave equations. As a method of analysis the ray method, the Laplace transform method for the viscoelastic impact and the method of spliced asymptotic expansions received for small times in the contact area and outside it are used. The local deformations in the contact area are taken into account in terms of two elastoplastic models (Aleksandrov–Kadomtsev and Kilchevskii models) and the viscoelastic Maxwell model. The stiffness of the Maxwell model’s element is expressed in terms of the integral operator with the exponential kernel of relaxation and thus the relationship for the contact force takes the integral form with a function of relaxation. The results of the present investigation can be used for the projecting and analysis of the planar constructions and their elements to impact loading in civil engineering and automotive industry.     

Oxidative transformations of acetonitrile on a La-Ce/MgO catalyst

In the interaction with air or a methane-air mixture in the presence of a ctalyst containing lanthanum and cerium oxides supported on magnesium oxide (periclase), acetonitrile underwent redox transformations that mainly resulted in carbon oxides. Acrylonitrile and propionitrile were also detected in the reaction products. The products of the oxidative dimerization of acetonitrile were formed to an insignificant extent.     

Elastoplastic model of cylindrical projectile-plate interaction

Elastoplastic models of the transverse impact of a cylindrical solid projectile on an isotropic elastic Uflyand-Mindlin plate have been studied using numerical simulation methods. Displacements of the plate points outside the contact region are caused by a transverse shear wave propagating at a finite velocity. This wave is formed at the moment of impact and represents a surface of strong discontinuity. Behind the transverse wave front, the unknown dynamic quantities are represented in the form of single-term ray expansions. The local crumpling of the target material proceeds in a quasi-static manner and its dependence on the contact force is described using an elastoplastic model. The dependence of the contact force on the elastoplastic properties of a target plate at the site of impact and on the contact disk inertia has been considered.     

Transverse impact of a ball on a sphere with allowance for waves in the target

The transverse impact of a solid projectile on an elastic spherical shell with a pivoting contour support has been studied. Inside the contact zone, the projectile-target interaction is described by a solution of the standard system of equations. Outside the contact zone, the points of the shell are displaced and the shell is deformed due to propagation of a nonstationary wave front. A solution in this region is constructed using ray series with variable coefficients representing jumps of the time derivatives of the unknown functions on the wave surface of strong discontinuity. These coefficients are determined to within arbitrary constants using momentless equations of motion of the shell points. The constants are determined by matching two solutions at the contact zone boundary. Using the obtained analytical expressions and plotted dependences for the contact force and dynamic inflection, it is possible to judge on the influence of the shell structure design on the dynamic characteristics of impact interaction.     

Catalytic Synthesis of Basic Petrochemical Products from C<Subscript>1</Subscript>-C<Subscript>4</Subscript> Alkanes

Effective catalysts for production of ethylene and aromatic hydrocarbons from methane and the propane-butane fraction are developed and investigated by physicochemical methods.__________Translated from Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 35 – 38, March – April, 2005.