Theoretical study on electron-free-radical scattering: An application to CF

In this work, a theoretical study on electron-CF collisions in the low- and intermediate-energy range is reported. More specifically, calculated elastic differential, integral, and momentum-transfer cross sections as well as grand total (elastic and inelastic) and absorption cross sections are presented in the (1-500)-eV energy range. A complex optical potential is used to represent the electron-molecule interaction dynamics, while the Schwinger variational iterative method combined with the distorted-wave approximation is used to solve the scattering equations. Comparison of the present results with existing experimental and theoretical data for electron collisions with NO (an isoelectronic molecule of CF) is made.66

Theoretical investigation of electron collisions with sulfur monoxide in the low- and intermediate-energy range

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)We report a theoretical study on electron collisions with the sulfur monoxide radical. More specifically, differential, integral, and momentum-transfer cross sections are calculated and reported in the 1-500 eV energy range. Calculations are performed at the static-exchange-polarization-absorption level of approximation. A combination of the iterative Schwinger variational method and the distorted-wave approximation is used to solve the scattering equations. Our study reveals shape resonances in both the doublet and quartet spin-specific scattering channels. The occurrence of such resonances may enhance the spin-flip effects. In addition, the comparison of our calculated total absorption cross sections with existing experimental total ionization cross sections is encouraging.802Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Preventable fractions of colon and breast cancers by increasing physical activity in Brazil: perspectives from plausible counterfactual scenarios

Background: Physical activity is associated with lower risk of colon and breast cancers. Herein we estimated preventable fractions of colon and breast cancers in Brazil by increasing population-wide physical activity to different counterfactual scenarios. Methods: We used data from a representative national survey in Brazil and corresponding relative risks of colon and postmenopausal breast cancers from a meta-analysis. Estimated cancer incidence was retrieved from GLOBOCAN and Brazilian National Cancer Institute. Five counterfactual scenarios for physical activity were considered: (i) theoretical minimum risk exposure level (≥8,000 metabolic equivalent of tasks-minute/week – MET-min/week); (ii) physical activity recommendation (≥600 MET-min/week); (iii) a 10% reduction in prevalence of insufficient physical inactivity (<600 MET-min/week); (iv) physical activity level in each state equals the most active state in Brazil; (v) closing the gender differences in physical activity. Results: About 19% (3,630 cases) of colon cancers and 12% (6,712 cases) of postmenopausal breast cancers could be prevented by increasing physical activity to ≥8,000 MET-min/week. Plausible counterfactual scenarios suggested the following impact on cancer prevention: reaching physical activity recommendation: 1.3% (1,113 cases) of breast and 6% (1,137 cases) of colon; 10% reduction in physical inactivity prevalence: 0.2% (111 cases) of breast and 0.6% (114 cases) of colon; most active state scenario: 0.3% (168 cases) of breast and 1% (189 cases) of colon; reducing gender differences in physical activity: 1.1% (384 cases) of breast and 0.6% (122 cases) of colon. Conclusions: High levels of physical activity are required to achieve sizable impact on breast and colon cancer prevention in Brazil

Elastic and absorption cross sections for electron-nitrous oxide collisions

In this work, we present a joint theoretical-experimental study on electron-N2O collisions in the intermediate energy range. More specifically, calculated and measured elastic differential, integral, and momentum-transfer cross sections, as well as calculated total and absorption cross sections are reported. The measurements were performed using a crossed electron-beam-molecular-beam geometry. The angular distribution of the scattered electrons was converted to absolute cross sections using the relative-flow technique. Theoretically, a complex optical potential is used to represent the electron-molecule interaction dynamics in the present calculation. The Schwinger variational iterative method combined with the distorted-wave approximation is used to solve the scattering equations. The comparison of the present calculated results with the measured results as well as with the existing experimental and theoretical data shows good agreement.65

Cross sections for electron scattering by carbon disulfide in the low- and intermediate-energy range

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)In this work, we report a theoretical study on e(-)-CS(2) collisions in the low- and intermediate-energy ranges. Elastic differential, integral, and momentum-transfer cross sections, as well as grand total (elastic+inelastic) and absorption cross sections, are reported in the 1-1000 eV range. A recently proposed complex optical potential composed of static, exchange, and correlation-polarization plus absorption contributions is used to describe the electron-molecule interaction. The Schwinger variational iterative method combined with the distorted-wave approximation is applied to calculate the scattering amplitudes. The comparison between our calculated results and the existing experimental and/or theoretical results is encouraging.811Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

ELECTRON-IMPACT EXCITATION OF THE D(3)-PI-(U)(-)(V=0, 1, 2, 3 N=1) STATES OF H-2 - CROSS-SECTIONS AND ANISOTROPY PARAMETERS

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Theoretical study on electron collisions with SiF and SiF(2) radicals in the low- and intermediate-energy range

A theoretical study on electron collisions with SiF and SiF(2) radicals in the low- and intermediate-energy range is reported. More specifically, calculated elastic differential, integral, and momentum transfer cross sections as well as total and total absorption cross sections are presented in the 1-1000-eV energy range. A complex optical potential is used to represent the electron-radical interaction dynamics, whereas the iterative Schwinger variational method combined with the distorted-wave approximation is used to solve the scattering equations. Comparison of the present results with the available theoretical and experimental results in the literature is made.76