[en] Training radon mitigators and ensuring that they provide high-quality work on the scale necessary to reduce radon to acceptable levels in the large number of homes and schools requiring some mitigation is a challenging problem. The US Environmental Protection Agency and several states have made commendable efforts to train mitigators and ensure that they provide quality services to the public. Expert systems could be used to extend and improve the effectiveness of these efforts. The purpose of this paper is to introduce the radon community to this promising new technology. The paper includes a description of a prototype system developed by Pacific Northwest Laboratory that illustrates several of the capabilities that expert systems can provide, a brief explanation of how the prototype works, and a discussion of the potential roles and benefits of fully-developed expert systems for radon mitigation. 4 refs., 3 figs

[en] A recent paper on the validity of counterpoise corrections in the intermolecular energy calculations was published by Yang and Kestner. The authors are particularly interested in this work since they previously worked on the same topic with a different approach. While the authors generally agree with their arguments and conclusions in the paper, the authors have found a few problems in some of the calculational results. It is the purpose of this comment to point out the possible errors in that paper

[en] The goal of this project has been to study the structure and dynamics of rare gas-halogen van der Waals molecules. These molecules are important because they provide the only chemical dynamics problem for which precise state-to-state dynamics can be determined by both experiment and full, three-dimensional quantum mechanics theory

[en] We report ab initio configuration interfaction calculations on the states of the gallium krypton (GaKr) molecule arising from the Ga(²P/sub 1/2,3/2/,²S/sub 1/2/) + Kr(¹S/sub O/) and Ga⁺(¹S/sub O/) + Kr(¹S/sub O/) separated atom limits. The potential energy curves for the states arising from the Ga(²P/sub 1/2,3/2/) limits, the I 1/2, II 1/2, and I 3/2 states, are found to be repulsive. The potential energy curves for the states arising from the Ga(²S/sub 1/2/) and Ga⁺(¹S/sub O/) limits, the III 1/2 and I 0 states, are both found to be weakly bound; D/sub e/ (III 1/2) = 0.047 eV and D (I 0) = 0.24 eV. The potential energy curves and transition moments obtained in the GaKr calculations have been used to simulate the curves and moments for InKr and TlKr. Using this data the absorption and emission coefficients of all three molecules have been calculated

No abstract available

[en] Published in summary form only

[en] Collision induced absorption at either the pump or Stokes wavelength could reduce the efficiency of Raman scattering of XeCl pump radiation in Pb vapor. Calculation of the collision induced absorption requires a knowledge of the different energy curves between the ground and upper states and the transition moment as a function of the internuclear distance. These curves were obtained in a first-order configuration interaction calculation of the PbHe, PbHe⁺, PbXe, and PbXe⁺ valence states. The atomic cores of Pb and Xe were replaced by relativistic effective core potentials so as to make the calculations tractable. The van der Waals interaction was also estimated by a variational perturbation calculation. These results were transformed to an Ω representation using an empirically determined spin--orbit operator. Using these theoretical data we estimate the collision induced absorption cross sections to be 10^-23 and 10^-21 cm² per atmosphere of Xe for the first and second Stokes lines in the case of a 308.0 nm pump. Cross sections for He will be about an order of magnitude smaller due to the smaller transition moments. The energy defect for the pump wavelength is estimated to be so large that no significant absorption is expected for either PbXe or PbHe collision partners. There are also no calculated curve crossings at an energy lower than 0.25 eV, which indicates a very small probability for deactivation of Pb(³P₂) by rare gas collision

[en] The published data on the synthesis and chemical transformations of xenon derivatives are generalised and analysed. The bibliography includes 489 references.

[en] A study was made on formation and death of eximeric molcules HgXe(A³O⁺) in the positive column of gaseous discharge of low power in the mixture of mercury vapors with xenon. Rate constants of recombination at ternary collisions and of dissociation of A³O⁺ state of HgXe molecule were determined. Measurements were conducted in 303-373 K atomic temperature range

[en] The beam smoothing technique for KrF laser drivers and uniformity measurement of accelerated targets are described. As a beam smoothing technique, broad-band random-phase irradiation is investigated. The rear sides of accelerated targets have been measured by face-on interferometry. This new method provides direct and precise two-dimensional information about initial deformation of the rear surface of the target. (orig.)