Synthesis and characterization of aryl substituted functionalized graphene sheets and their electrochemical behavior

Journal of Solid State Electrochemistry - We report the electrochemical behavior of free-standing functionalized graphene sheet electrode in a potential window corresponding to that of high-voltage...     

Role of Heterogeneous Chain Termination in Flame Propagation

Kinetics and Catalysis - The kinetic characteristics of propagating flame were shown to depend on the chemical properties of the contacting solid surface and on the rates of heterogeneous...     

Comparison of Yield,Chemical Composition and Antimicrobial Activity of Distichochlamys citrea Rhizome Essential Oils Obtained by Different Extraction Methods

Moscow University Chemistry Bulletin - Hydrodistillation (HD), steam distillation (SD) and microwave-assisted hydrodistillation (MAHD) extraction methods were assessed for their effects on yield,...     

Flow characteristics of two-phase dispersed annular streams in heated tubes

Patterns and characteristics of flow through heated tubes are investigated on the basis of concepts of two-phase dispersed annular flow patterns [1] within the framework of the three-velocity and single-temperature equilibrium model, with flowrates of the mixture not too close to critical. Conditions for onset of burnout of the second kind, i.e., deterioration in the transfer of heat leading to an abrupt rise in the temperature of the heating surface, and, as such, associated with desiccation of the thin film of liquid on the wall [2, 3], are investigated. Hydraulic drag, the flowrate of liquid in the film, and the true steam content by volume are among the factors discussed. Two-phase flow patterns in dispersed annular flow are characterized by the combined motion of the three components of the mixture: vapor, the liquid wall film, and droplets. The assumption entertained is that each component of the mixture acquires its own velocity, and that the temperature of the mixture is equal, in each cross section through the channel, to the saturation temperature at the pressure prevailing in the particular cross section.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 78–88, July–August, 1973.     

Deformation of liquid jets and drops injected into a gas stream

The process of deformation of liquid drops and jets is examined on a broad interval of two-phase flow parameters. The shape of a jet penetrating a gas stream directed at an angle to the jet-particle velocity vector is determined.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 3, pp. 82–88, May–June, 1971.In conclusion the authors thank A. K. Simonovskii for his useful comments.     

Study of the attenuation of a detonation wave with a two-front structure by the boundary (shock) layer method

The possibility that a plane overcompressed detonation wave may undergo a transition to the Chapman-Jouguet mode during its attenuation is considered on the basis of the two-front model, allowing for the change in flow parameters in the interval between the fronts. G. G. Chernyi's approximate method of boundary (shock) layer is used in order to describe the flow of the gas in this interval. The use of this method is justified by the fact that the velocity of propagation of the detonation wave is extremely great (order of several km/sec), and the gas between the compression jump and the combustion front is strongly compressed.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No, 3, pp. 59–65, May–June, 1971.     

Plane steady vibration of an elastic wedge

The problem of plane steady vibration of an elastic wedge of arbitrary angle (less than 180 degrees) subject to harmonic normal and shearing tractions on its faces is reduced to a system of singular integral equations by the superposition of two half-plane solutions. The integral equations have kernels with Cauchy singularities of a non-translation type, except for the 90 degree wedge. The locations of these singularity lines are shown graphically as a function of wedge angle.     

An approach to computer control for legged vehicles

Observation of the locomotion of animals and human beings in difficult terrain makes it quite obvious that legged locomotion offers substantial mobility advantages over conventional wheeled or tracked systems. However, effective adaptation of legged locomotion principles to off-road vehicles has to date been frustrated by the complexity of the joint coordination control problem and by the lack of suitable sources of power for individual leg joints. This paper is addressed to the first problem and is intended to show that some of the techniques used in aircraft autopilots can be adapted to legged vehicle control. The main results presented are derived from a computer simulation study of a system in which vehicle speed and direction are determined by a human operator while individual joint commands are generated automatically by a digital computer. Present indications are that such a vehicle might be as easy to control as a conventional wheeled or tracked automotive system.     

Reflection operator methods for elastic waves I-irregular interfaces and regions

A wide range of reflection and transmission problems for elastic waves can be represented formally in terms of reflection and transmission operators. The action of these operators on the incident field is to produce the corresponding reflected and transmitted displacement fields. For interface problems, free surface reflections and reflections from a region, the operators can be represented in terms of a surface integral of the product of the Green's tensor and a force system which may be determined by the solution of a single integral equation.