[en] During 1978, these conclusions were reached and are reported: Innershell Coulomb ionization cross sections show significant relativistic effects even for the lighter atoms, because ionization occurs near the nucleus in our range of low particle energies. Atomic excitation and ionization in deep atom--atom collisions can be described in terms of a model with random walk in energy space to the continuum. This model may be best suited for the analysis of heavy ion--atom encounters. Energy straggling of charged particles in matter are affected by inhomogeneities in and surface conditions of the medium. Using molecular ions as incident projectiles it is concluded that moving protons do not have bound states in solids. Projectiles in close proximity to each other exhibit larger energy losses than isolated projectiles indicating interactions of the electron density fluctuations established behind moving projectiles in solids. Heterogeneous oxidation of SO₂ by holes has been found at an organic (PAH) aqueous interface. The process has a reasonably high quantum efficiency (approx. >0.1) for anthracene. Various experiments are being carried out to determine whether SO₃/sup =/ or HSO₃- is involved. Photoemission from PAH organic aerosols has been investigated. The rate of emission from tetracene is found to go as the maximum electron kinetic energy cubed. It is found that the particle may be used as an electron spectrometer for determining the electron kinetic energy distribution. A new way of characterizing small aerosols by mass has been found. The method utilizes the detection of a single electron imbalance in a Millikan chamber. Aerosol masses as small as 1 pgm can be measured to better than 1%. The potent carcinogen benzo (a) pyrene (BP) when metabolized in vivo is found to have a physical structure in which the BP7,8-dihydrodial 9,10-oxide adduct (BPDE) is bound on the outside of the helix. Models and measurements support this conclusion