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Energy-transport effects can alter the structure that develops as a supernova evolves into a supernova remnant. The Rayleigh–Taylor instability is thought to produce structure at the interface between the stellar ejecta and the circumstellar matter, based on simple models and hydrodynamic simulations. Here we report experimental results from the National Ignition Facility to explore how large energy fluxes, which are present in supernovae, affect this structure. We observed a reduction in Rayleigh–Taylor growth. In analyzing the comparison with supernova SN1993J, a Type II supernova, we found that the energy fluxes produced by heat conduction appear to be larger than the radiative energy fluxes, and large enough to have dramatic consequences. No reported astrophysical simulations have included radiation and heat conduction self-consistently in modeling supernova remnants and these dynamics should be noted in the understanding of young supernova remnants. Radiation and conduction are generally considered as the main energy transport mechanisms for the evolution of early supernova remnants. Here the authors experimentally show the role of electron heat transfer on the growth of Rayleigh–Taylor instability in young supernova remnants.

—For rolling of balls, one of the main parameters for both calculating passes and developing a model for a roll is the roll spacing at the crossing point (zones where the edges of the rolls are as close as possible to each other) in addition to the roll diameter, the roll body length, and the section length. A method is developed to calculate the roll spacing at the crossing point. The calculation results are used to analyze and choose rational tuning parameters of rolls for rolling balls at the EVRAZ NTMK ball-rolling mill. The analysis is carried out on new rolls and rolls after the first, second, third, and fourth remachining of screw ball-rolling grooves. The data are systematized to plot point curves for tuning indicators, and the graphical data are used to make a polynomial approximation. Equations are derived for the functions of the tuning parameters.

An experimental and numerical systematic study of the growth of the Richtmyer–Meshkov instability-induced mixing following a re-shock is made, where the initial shock moves from the light fluid to the heavy one, over an incident Mach number range of 1.15–1.45. The evolution of the mixing zone following the re-shock is found to be independent of its amplitude at the time of the re-shock and to depend directly on the strength of the re-shock. A linear growth of the mixing zone with time following the passage of the re-shock and before the arrival of the reflected rarefaction wave is found. Moreover, when the mixing zone width is plotted as a function of the distance travelled, the growth slope is found to be independent of the re-shock strength. A comparison of the experimental results with direct numerical simulation calculations reveals that the linear growth rate of the mixing zone is the result of a bubble competition process.

The most important component of any rolling mill is the calibration of the rolls. The ability to obtain a finished product of high quality at minimal cost depends on the right calibration. According to the previous experience and practice a large number of different calibrations for the flange profiles production are known. The universal 'concept of two-stage optimization', consisting of two successively carried out optimization stages developed in the Department of Metal Forming of the Ural Federal University in relation to optimization of the roll calibration for flange shape rolling is considered in this article. Common features of these shapes classification and their variation levels are identified and justified. This developed classification structure is the basis for the formation of spaces of groove schemes, due to which the groove space is formed. In the software implementation the groove space is represented as a 'groove database'. In the future this database will be used to form the space of calibration schemes that are fundamentally suitable for these shapes rolling.

MathCAD software is used to solve the variation problem formulated in part 1 regarding the rolling of rail in universal grooves. On that basis, the laws governing the shaping of the metal in obtaining uniform deformation (with the same reduction coefficient) over all elements of the rail profile may be established. The dependence of the lateral-reduction coefficients of the flanges at the head and base of the rail blank are determined, along with the dependence of the flange increment (shrinkage) on the geometric parameters of the deformation region and the frictional conditions. The corresponding formulas are derived and used in calculating the best reduction conditions and roller groove configuration in the production of high-quality rail on modern mills.

A mathematical model of the shaping of metal on rail rolling in universal grooves is developed by variation so as to minimize the total power consumption, using up-to-date computer resources. This model permits uniform deformation of all elements of the rail profile. In particular, a geometric model of the deformation region is formulated, and the kinematically possible flow-rate field for the metal is established. The boundary conditions are determined, and the basic system of equations is derived, including the energy-balance equation and the condition for a minimum of the variational functional. In contrast to familiar variational solutions, all the equations in the mathematical model are calculated without simplifications. That increases the accuracy of the calculation. The proposed model may be used to determine the metal flow for rolling in universal grooves.

In thick shell implosions, most of the kinetic energy is used to assemble the cold fuel rather than to heat the hot spot. A significant increase in the hot-spot compression and reduction of the driver energy required for ignition can be accomplished by launching a shock during the final stage of the implosion. In direct-drive inertial confinement fusion (ICF), the ignitor shock can be launched by a power spike at the end of the laser pulse. For targets with the same adiabat and implosion velocities, the laser energy required for ignition is significantly lower for shock-ignition ICF than for standard ICF.

Engineering formulas for the basic technological parameters when rolling I beams in universal grooves are derived on the basis of the variational principle of minimum total power. Those parameters are the increment and reduction of the flanges; the contact pressure at the horizontal and vertical rollers; and the rolling forces and torques.

The three-dimensional (3D) turbulent mixing zone (TMZ) evolution under Rayleigh–Taylor and Richtmyer–Meshkov conditions was studied using two approaches. First, an extensive numerical study was made, investigating the growth of a random 3D perturbation in a wide range of density ratios. Following that, a new 3D statistical model was developed, similar to the previously developed two-dimensional (2D) statistical model, assuming binary interactions between bubbles that are growing at a 3D asymptotic velocity. Confirmation of the theoretical model was gained by detailed comparison of the bubble size distribution to the numerical simulations, enabled by a new analysis scheme that was applied to the 3D simulations. In addition, the results for the growth rate of the 3D bubble front obtained from the theoretical model show very good agreement with both the experimental and the 3D simulation results. A simple 3D drag–buoyancy model is also presented and compared with the results of the simulations and the experiments with good agreement. Its extension to the spike-front evolution, made by assuming the spikes' motion is governed by the single-mode evolution determined by the dominant bubbles, is in good agreement with the experiments and the 3D simulations. The good agreement between the 3D theoretical models, the 3D numerical simulations, and the experimental results, together with the clear differences between the 2D and the 3D results, suggest that the discrepancies between the experiments and the previously developed models are due to geometrical effects.