RESUMO
As a consequence of the development of AM, strategies have been developed to optimize the printing process, which focuses on reducing manufacturing time, such as using genetic algorithms (GAs), among others. The effect caused by the modification of path patterns is an effect of interest in two aspects: dimensional assurance focused on the compliance of the dimensions of the components in comparison with the digital design of the components, and the structural composition and resistance that the printing process itself can generate. This paper aims to present the effect of optimizing the path of fused filament fabrication (FFF) equipment on the dimensional finish and structural quality of a multi-geometric component using computed tomography. For this purpose, a template composed of 23 geometric elements, printed using FFF technology and PLA as the base material, is used. The results show an 11% reduction in the total process time required to print the component. The effect on the dimensional precision of different geometric elements was identified. In addition, it was possible to ensure that the structural quality of the multi-geometric component was not affected by the modification of the path required by the printing process.
RESUMO
OBJECTIVE: Outdoor smoking bans have been implemented to reduce secondhand smoke exposure and cigarette littering. We aimed to explore outdoor smoking behaviours, cigarette littering, and support towards a recently enacted outdoor smoking ban in Baja California, Mexico. METHODS: From October 2013 to April 2014 a representative sample of 800 adults from urban areas of Baja California was surveyed to obtain information on demographics, smoking status, opinion towards outdoor smoking bans in general and in specific locations, and perceptions and habits regarding cigarette littering. Descriptive statistics and Poisson regression analyses were conducted to estimate prevalence ratios and corresponding 95% CI taking into account the complex survey design. RESULTS: Outdoor smoking was frequently observed, as 86.8% of the population reported having seen people smoking in parks and beaches and 94.4% in open venues such as concerts or stadiums. A smoking ban in all outdoor areas was supported by 71.8% of Baja California residents. Site-specific support ranged from 80% (stadiums) to 89% (public parks). Support for the ban was higher among never and ex-smokers than in current smokers. Cigarette littering was negatively perceived by 98% of the participants, yet 45% of all cigarettes smoked were thrown on the ground. Based on cigarette consumption and butt littering reported in the survey, we estimated that 27 million cigarette butts become litter every month in urban areas of Baja California. CONCLUSIONS: Outdoor smoking is still frequent in outdoor areas where people gather, and an important source of littering. We found substantial public support towards the outdoor smoking ban, which should translate into easier implementation and compliance in Baja California, Mexico.
