Progress in computer hardware and improvement of numerical methods made solution of the Boltzmann equation for rather complex gas dynamic problems real. The method developed by the author is based on a projection technique for evaluation of the collision operator. The computed collision integral is conservative by density, impulse, and energy, and became equal to zero when the solution has a fo...

Molecular scattering behavior has generally proven difficult to study at low collision energies. We formed a molecular beam of OH radicals with a narrow velocity distribution and a tunable absolute velocity by passing the beam through a Stark decelerator. The transition probabilities for inelastic scattering of the OH radicals with Xe atoms were measured as a function of the collision energy in...

We present a quantum mechanical study of the diatomic hydrogen H(S) and oxygen O(P ) collision and energy transfer for its four molecular symmetry (XΠ, Σ, Π, Σ−), which is important for the investigation of many processes of astrophysical and chemical interests including the one on molecular cooling, trapping or Bose-Einstein condensation. We compute the rovibrational spectra for the (XΠ) state...

The field of molecular biology is in a remarkably rapid period of change, as the genome sequencing projects and new experimental technologies have generated an explosion of data To analyze and draw insights from the vast amounts of information, biologists use a new generation of bioinformatics software tools, often working closely with mathematicians and computer scientists There are elements o...

Context. Whether nanoparticles bounce or stick during collisions determines whether particles grow fragment, hence shaping collision-induced agglomeration processes. The collision behavior of organic matter may strongly differ from that silica ice grains. Aims. We explore the microscopic processes underlying bouncing nanoparticles. Methods. Molecular dynamics simulations based on a reactive pot...

We present a series of numerical studies of the interaction of colliding radiative, hydrodynamic young stellar outflows. We study the effect of the collision impact parameter on the acceleration of ambient material and the degree to which the flow is isotropized by the collision as a mechanism for driving turbulence in the parent molecular cloud. Our results indicate that the high degrees of co...

The rotationally inelastic scattering of methyl radical with Ar and N2 is examined at collision energies of 330 ± 25 cm(-1) and 425 ± 50 cm(-1), respectively. Differential cross sections (DCSs) were measured for different final n' rotational levels (up to n' = 5) of the methyl radicals, averaged over k' sub-levels, using a crossed molecular beam machine with velocity map imaging. For Ar as a co...

A kinetic equation which combines the quasiparticle drift of Landau’s equation with a dissipation governed by a nonlocal and noninstantaneous scattering integral in the spirit of Enskog corrections is discussed. Numerical values of the off-shell contribution to the Wigner distribution, of the collision duration and of the collision nonlocality are presented for different realistic potentials. O...

Collision cross sections between oxygen molecules and helium atoms are computed at translational energies between 0.1 K and 10.0 K, motivated by the recently demonstrated cooling of molecules by a helium buffer gas. Detailed calculations based on a rigid-rotor model demonstrate the differences among various isotopic combinations of oxygen atoms and also serve to illustrate resonant features uni...

We examine the effect of theoretically varying the collision-system reduced mass in collisions of He with vibrationally excited molecular hydrogen and observe zero-energy resonances for select atomic “hydrogen” masses less than 1 u or a “helium” mass of 1.95 u. Complex scattering lengths, state-to-state vibrational quenching cross sections, and a low-energy elastic scattering resonance are all ...