Evidence for a New Compact Symmetric Fission Mode in Light Thorium Isotopes.

Taking benefit of the R3B/SOFIA setup to measure the mass and the nuclear charge of both fission fragments in coincidence with the total prompt-neutron multiplicity, the scission configurations are inferred along the thorium chain, from the asymmetric fission in the heavier isotopes to the symmetric fission in the neutron-deficient thorium. Against all expectations, the symmetric scission in the light thorium isotopes shows a compact configuration, which is in total contrast to what is known in the fission of the heavier thorium isotopes and heavier actinides. This new main symmetric scission mode is characterized by a significant drop in deformation energy of the fission fragments of about 19 MeV, compared to the well-known symmetric scission in the uranium-plutonium region.

First Measurement of Several ß-Delayed Neutron Emitting Isotopes Beyond N=126.

The ß-delayed neutron emission probabilities of neutron rich Hg and Tl nuclei have been measured together with ß-decay half-lives for 20 isotopes of Au, Hg, Tl, Pb, and Bi in the mass region N≳126. These are the heaviest species where neutron emission has been observed so far. These measurements provide key information to evaluate the performance of nuclear microscopic and phenomenological models in reproducing the high-energy part of the ß-decay strength distribution. This provides important constraints on global theoretical models currently used in r-process nucleosynthesis.

Exposure to environmental tobacco smoke in Chaves after the implementation of the law 37/2007. A cross-sectional study in two healthcare settings.

INTRODUCTION: Environmental tobacco smoke (ETS) is currently the main indoor pollutant and causes a high morbility and mortality. A partial restriction came into force in Portugal, in 2008, law 37/2007, trying to control, define and regulate smoke-free environments. OBJECTIVE: To assess exposure and perceived impact of the law 37/2007 on exposure to ETS among adults attending to the two health care facilities of Chaves (Portugal). METHOD: A cross-sectional survey on tobacco consumption and exposure to ETS was undertaken in Chaves (Northern Portugal) between November 2009 and February 2010. All the patients, over 17, attending to any of the Chaves Primary Care Facilities were interviewed. Patient enrolment was done on a rolling basis covering all days of the week. A face to face interview was carried out and a carbon monoxide was measured. Prevalence and means are shown with 95% confidence intervals. RESULTS: 287 patients participated in the survey, 56% were males and the mean age was 54 years. Smoking prevalence was 23,6%, significantly higher in males (31% vs 17%). 46,2% reported exposure tobacco smoke elsewhere (53% in males vs. 40% in females). Smokers declared to be more exposed to ETS than non-smokers. 16.2% of the population declared to be exposed at home, 14% at work and 33% at leisure places. The highest decrease in perception of passive exposure was found for restaurants (95%). In nightclubs 68% of the participants stated that exposure has remained unchanged. CONCLUSION: The tobacco control law offered protection against tobacco smoke in several closed public spaces. However, a significant proportion of the population remains exposed. This study highlights the ineffectiveness of a partial ban. A comprehensive law is, therefore, required in Portugal.