[en] We calculate the different nuclear breakup cross sections (diffraction, stripping and absorption) within the Serber model for single-nucleon as well as two-neutron halos (so-called Borromean nuclei). In contrast to calculations up to now, we use realistic wave functions as well as a realistic model for the interaction with the target. We show results of our calculations for total as well as differential cross sections

[en] We develop a semi-classical theory for the excitation and breakup of a π⁺π^--atom moving at relativistic energies in the screened Coulomb field of a nucleus. Cross sections for various π⁺π^--atomic transitions and target nuclei are evaluated analytically and numerically in first-order perturbation theory. Anticipating further refinement of our theory, special attention is devoted to identifying the various approximations and estimating their associated errors

[en] Relativistic corrections for the elastic scattering of heavy ions in the sub Coulomb regime are given. The case of two identical particles is treated especially. The deviation from the Rutherford (Mott) cross section is calculated by using the Todorov equation and the Darwin Hamiltonian, resp.. It is shown, that both approaches lead to the same results for small kinetic energies. Furthermore we discuss the applicability of the WKB method for calculating the phase shifts and the possibility of using a classical perturbative approach in the case of nonidentical particles. (orig.)

No abstract available

[en] Virtual radiative corrections due to the long-range Coulomb forces of heavy nuclei with charge Z may lead to sizeable corrections to the Born cross-section usually used for lepton-nucleus scattering processes. An introduction and presentation of the most important issues of the eikonal approximation is given. We present calculations for forward electroproduction of rho-mesons in a framework suggested by the VDM (vector dominance model), using the eikonal approximation. It turns out that Coulomb corrections may become relatively large. Some minor errors in the literature are corrected. (orig.)

No abstract available

[en] We calculate the inelastic electron- and muon-pair production in peripheral relativistic heavy ion collisions in the region of large Q² of one of the photons. This offers a possibility to study the quark distribution functions in ions in ''ultraperipheral heavy ion collisions''. The calculations are compared with those making use of the equivalent photon and the equivalent lepton approximation. We compare the results for Pb-Pb and Pb-p collisions at RHIC (γ∼100) and LHC (γ∼3000) energies. Furthermore we include nuclear modifications to the parton distribution functions in our calculations to study their effect on the cross sections. (orig.)

[en] Particulate matter emissions and some components of the particles were measured in the exhaust from combustion equipment used in oil and gas production operations near Bakersfield, California. The combustion sources included a 22.5 MW (electric) turbine generator, a 342-Bhp rich-burn spark ignition engine, and a 50 million Btu/h steam generator, all fired using natural gas. The particle components and measurement techniques were as follows: (1) Calcium, magnesium, sodium, silicon, and iron were measured using laser-induced breakdown spectroscopy (LIBS), (2) particle-bound polycyclic aromatic hydrocarbons (PAH) were detected using the charge produced by photoionization, (3) particles having sizes between 0.1 and 7.5 (micro)m were counted using an instrument based on light scattering, and (4) total particulate matter was measured according to US EPA Method 5. Not all of the methods were applied to all of the sources. Measurements were also made in the ambient air near the combustion air inlets to the units, for comparison with the concentrations in the exhaust, but the inlet and outlet measurements were not done simultaneously. Calcium, sodium, and silicon were found in the exhaust from the steam generator at concentrations similar to those in the ambient air near the inlet to the burner. Sodium and silicon were observed in the engine exhaust at levels a factor of four higher than their concentrations in the air. The principal metal observed in the engine exhaust was calcium, a component of the lubricating oil, at a concentration of 11.6 (micro)g/m³. The air entering the gas turbine is filtered, so the average concentrations of metals in the turbine exhaust under steady operating conditions were even lower than in the air. During start-up following a shut-down to wash the turbine, silicon and iron were the major species in the stack, at concentrations of 6.4 and 16.2 (micro)g/m³, respectively. A possible source of silicon is the water injected into the turbine for NO_x control. Iron-containing particles are expected to be scale from ferrous metals. A commercial photoelectric aerosol sensor was used to measure PAH adsorbed on particles in the exhaust from the steam generator and the rich-burn engine. The conversion of the instrument readings to PAH concentrations is dependent upon the specific distribution of PAH species present. Using the typical calibration factor recommended by the instrument manufacturer, the estimated average concentration of particle-bound PAH was below the instrument detection limit (3--10 ng/m³) in the stack gas from the steam generator, and was estimated to be 0.045--0.15 (micro)g/m³ in the exhaust from the rich-burn engine. Particle mass concentrations estimated from number concentrations determined using the particle counting and sizing instrument were only small fractions of the concentrations measured using Method 5. This is thought to be due primarily to the limited range over which size was quantified (0.1 to 7.5 (micro)m) and the poor efficiency with which the sampling system transferred large particles

No abstract available

[en] Short communications only