Binary fission in Tb and Ag by 600 MeV protons

The binary fission process in ¹⁵⁹Tb and ^natAg induced by 600 MeV protons has been investigated yielding fission cross sections (1.9 and 1.0 mb, respectively) and mean values of the total kinetic energies (100 and 62 MeV, respectively).     

Pointwise convergence and radial limits of harmonic functions

This paper characterizes those real-valued functions on a compact setK in ℝ ⁿ that can be expressed as the pointwise limit of a sequence (h _m ), where each functionh _m is harmonic on some neighbourhood ofK. It also characterizes those functions on the unit sphere that can arise as the radial limit function at infinity of an entire harmonic function. Both results rely on important recent work of Lukeš et al. concerning approximation of affine Baire-one functions.     

Mass yields in the binary fission of Ag,La and Tb

The mass distributions from the binary fission of Ag, La and Tb induced by 600 MeV protons are presented. The experimental results are compared with the predictions of macroscopic theories, in particular the version of the liquid drop model including dynamical and statistical effects.     

The Principle of Minimum Chemical Distance (PMCD)

The principle of minimum chemical distance (PMCD) allows one to formulate the isoprene rule, the conversion of tetrahydrodicyclopentadiene into adamantane, five syntheses of colchicine, and the syntheses of C₁₆-hexaquinacene, morphine and strychnine as optimization problems which can be solved by computers in less than a second. The principle of minimum chemical distance is based on an algebraic theory of constitutional chemistry. The PMCD, a corollary to the well known principle of minimum structure change, is a quantitative heuristic rule which serves as the foundation of the computer-assisted combinatorial solution of a great variety of chemical problems, particularly in substructure analysis, the study of reaction mechanism, and the design of syntheses.     

Large-Eddy Simulation of the Flow Over a Circular Cylinder at Reynolds Number 3900 Using the OpenFOAM Toolbox

The flow over a circular cylinder at Reynolds number 3900 and Mach number 0.2 was predicted numerically using the technique of large-eddy simulation. The computations were carried out with an O-type curvilinear grid of size of 300 × 300 × 64. The numerical simulations were performed using a second-order finite-volume method with central-difference schemes for the approximation of convective terms. A conventional Smagorinsky and a dynamic k-equation eddy viscosity sub-grid scale models were applied. The integration time interval for data sampling was extended up to 150 vortex shedding periods for the purpose of obtaining a fully converged mean flow field. The present numerical results were found to be in good agreement with existing experimental data and previously obtained large-eddy simulation results. This gives an indication on the adequacy and accuracy of the selected large-eddy simulation technique implemented in the OpenFOAM toolbox.     

Lp-estimates for the nonlinear spatially homogeneous Boltzmann equation

This paper studies L^p-estimates for solutions of the nonlinear, spatially homogeneous Boltzmann equation. The molecular forces considered include inverse k^th-power forces with k > 5 and angular cut-off.The main conclusions are the following. Let f be the unique solution of the Boltzmann equation with f(v,t)(1 + ¦v²¦)^(s ₁ ^{+ /p)/2} L¹, when the initial value f ₀ satisfies f ₀(v) 0, f ₀(v) (1 + ¦v¦²)^(s ₁ ^{+ /p)/2} L¹, for some s₁ 2 + /p, and f ₀(v) (1 + ¦v¦²)^s/2 L^p. If s 2/p and 1 < p < , then f(v, t)(1 + ¦v¦²)^{(s s} ₁)^/2 L^p, t > 0. If s >2 and 3/(1+ ) < p < , thenf(v,t) (1 + ¦v¦²)^(s(s ₁ ^{+ 3/p))/2} L^p, t > 0. If s >2 + 2C₀/C₁ and 3/(l + ) < p < , then f(v,t)(1 + ¦v¦²)^s/2 L^p, t > 0. Here 1/p + 1/p = 1, x y = min (x, y), and C₀, C₁, 0 < 1, are positive constants related to the molecular forces under consideration; = (k – 5)/ (k – 1) for k^th-power forces.Some weaker conclusions follow when 1 < p 3/ (1 + ).In the proofs some previously known L-estimates are extended. The results for L^p, 1 < p < , are based on these L-estimates coupled with nonlinear interpolation.