The halocarbon CFC-11 has extensively been used as a blowing agent for polyurethane (PUR) insulation foams in home appliances and for residential and industrial construction. Release of CFCs is an important factor in the depletion of the ozone layer. For CFC-11 the future atmospheric concentrations will mainly depend on the continued release from PUR foams. Little is known about rates and time frames of the CFC release from foams especially after treatment and disposal of foam containing waste products. The CFC release is mainly controlled by slow diffusion out through the PUR. From the literature and by reevaluation of an old reported experiment, diffusion coefficients in the range of 0.05-1.7 x 10(-14) m2 s-1 were found reflecting differences in foam properties and experimental designs. Laboratory experiments studying the distribution of CFC in the foam and the short-term releases after shredding showed that about 40% of the CFC is solubilized in the PUR phase, and that up to 10% of the total content will be released within a few weeks if the foam is shredded down to 2-cm sized pieces. For smaller pieces the quick release will be larger. Fifty percent of residual CFC content will be released within 9-300 years from 2-cm pieces based on the range in diffusion coefficients reported. For larger pieces the initial release is insignificant, and the release time frames are much longer than for the shredded foam.

We present ab-initio CCSD calculations of the 3−5 He ground states. We perform these calculations using a mixed basis of oscillator and complex Woods-Saxon states for chosen partial waves. From this starting point, we build a spherical Gamow-Hartree-Fock basis from a renormalized interaction of the low-momentum type generated from the N 3 LO two-body potential. The GamowHartree-Fock basis, which is a Berggren basis, treats bound, resonant, and continuum states on an equal footing, and is therefore optimal for the description of nuclear states which may be embedded in the continuum. Within this ab-initio approach, we are able to calculate that 3−4 He are stable against particle decay, while 5 He has a non-negligible width and is therefore unstable with respect to one neutron emission, as is the case experimentally. We illustrate from these calculations that the CCSD approach is as accurate for closed-shell nuclei as for open-shell nuclei with ±1 nucleon outside a closed-shell. Finally, we perform various tests on the convergence of our CCSD results. We find that our results are well converged with respect to basis size and discretization of the continuum integral defining our Berggren basis.