It is shown that the initial state of uranium dioxide powder has no effect on the density, microstructure, and strength of pellets. Pore-forming agents and U 3 O 8 used in fabrication lower the pellet strength because their particles are not spherical. To increase pellet strength, it is recommended that U 3 O 8 be subjected to special processing to spheroidize the particles before mixing for uranium dioxide powder.
We present a solution for the problem of the distribution of temperature and that of the intensity of heat flows in bodies that are in contact in the ease of steady-state heat transfer and great velocities of motion.The description of certain technological processes is frequently reduced to the following heat problem (Fig. 1).A rod II is moving at a velocity v 1 in the direction of the x-axis over the surface of a semiinfinite plate I. The rod is moving simultaneously at a velocity v 2 = vt/k in the plane perpendicular to the vector of the velocity vj.At each point of contact between the rod and the semiinfinite plate a quantity of heat equal to q is liberated. The initial temperature of the bodies is t o .We have to find the temperature distribution at the contact area and to determine the quantity of heat which is transferred to each of the bodies in contact.Let us examine the solution of this problem for the case of steady-state heat transfer and for the case of great velocities of body motion.We will assume the thermophysical properties of the bodies to be constant and identical, as well as independent of temperature.We will assume the bodies in contact to be thin, and we will neglect the variation in temperature through the body thickness.Let us write [1] the equation for the propagation of heat in a semiinfinite plate in a coordinate system associated with the heat source in the following manner:at + I, ka-w -/y! or in dimensionless form 0O 020 a20At a great velocity, the temperature gradient in the direction ~ of the displacement of the heat source is small in comparison with the gradient along the normal to the displacement axis, i. e,,
OO 80a~ a~qThis provides a basis for replacing the process of heat propagation in the plate by a set of independent heatpropagation processes in elementary rods perpendicular to the x-axis [2].Kuibyshev Polytechnic Institute, Kuibyshev.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.