Use of Nuclear Energy in Outer-Space Systems

Atomic Energy - The history and direction of further development of space nuclear energetics are examined. The functional diagram and principle of operation of a promising, powerful,...     

Hydrogen-powered automobiles: Problems and solutions

The development of hydrogen power for switching the most energy-intensive segments of industry and transportation to a qualitatively new energy carrier - hydrogen - as a strategic direction for decreasing the acuteness of the problems of environmental pollution and the growing shortage of petroluem-based fuel for automobiles is examined.It is concluded for vehicular transportation systems in megalopolises and large cities that the main solution is to develop an ecologically safe means of transportation powered by an electrochemical generator operating on hydrogen and atmospheric air. A preliminary conclusion is drawn on the basis of a comparison of various types of electrochemical generators that electrochemical generators with a solid-polymer membrane have merit.Various systems for storing hydrogen in an automobile are examined. The system which is closest to practical implementation is a system for storing hydrogen gas at high pressure in a tank made of composite materials. An assessment is made of the danger that the hydrogen stored in a high-pressure tank in an automobile will catch fire or explode.Translated from Atomnaya Énergiya, Vol. 97, No. 5, pp. 380–387, November, 2004.     

Oxidation of ZrB2–SiC–ZrSi2 ceramics in oxygen

The oxidation of ZrB₂–SiC and ZrB₂–SiC–ZrSi₂ ceramics of different composition has been studied experimentally at 1500 °C in pure oxygen for up to 50 h. ZrB₂–SiC–ZrSi₂ ceramics proved to be the most oxidation-resistant at ZrSi₂ contents of less then 4 wt%. These ceramics were more oxidation-resistant than ZrB₂–SiC ceramics. An analytical model of growth kinetics for a multilayered scale based on an oxidation–diffusion balance was developed and tested.     

Space nuclear power systems: Yesterday, today, and tomorrow

The present work deals with issues related to the development of space nuclear power systems that offer great potential for increasing the effectiveness of space activities.     

Nonisothermal flow in a conic liquid trap under conditions of atmosphere-free space

A nonisothermal film flow is considered, which is formed on the inside surface of a conic liquid trap, to the inlet of which a homogeneous flow of monodisperse droplet medium is delivered under conditions of atmosphere-free space. Asymptotic models of steady film flow are constructed and investigated for the conditions of inertial deposition of droplets under the assumption of small relative thickness of film and of the effect of secondary droplets formed upon deposition on the film surface. For a slow flow, the shape of the surface and the parameters of the film are found analytically. A parametric numerical investigation of distributions of velocity, temperature, and film thickness is performed for the general case. The parameters of flow in the inlet section of the offtake channel are found, and the conditions are determined which are required for maintaining a steady-state mode of operation of the drip pan.     

CARS thermometry of polyatomic gases: SF6

Coherent anti-Stokes Raman spectroscopy (CARS) has been used to study the temperature behavior of SF6gas. In the temperature range 200-1000 K, evaluation of CARS bandwidths and lineshifts resuited in a relatively precise temperature determination. The advantages of a CARS-based SF6thermometer are discussed in detail.