Life cycle assessment of residual forestry biomass chips at a power plant: a Portuguese case study

The residual forest biomass (RFB) sector has been experiencing strong development at European level and particularly in Portugal mainly due to the increase of energy production from renewable sources. The aim of this study is to assess the environmental impacts of eucalyptus RFB chips production chain in Portugal. The environmental and economic impact comparison of the processes included in the production chain is presented as well. The environmental impacts were calculated by the life cycle assessment approach described in the ISO 14040 series of standards. The production chain assessed included all processes from eucalyptus forest until the delivery of RFB chips at the power plant. The main conclusion of this study is that eucalyptus wood production is the process that presents the greatest environmental impact through the product life cycle.

Sleep and academic performance of Portuguese teenagers

Abstract: Sleep has numerous important functions in the body, such as consolidation of memory, concentration and learning. Changes in sleep cycles in adolescents lead to sleep deprivation with consequences to academic performance. Our research question was What are the sleep habits that influence school performance (study environment, study planning, study method, reading skills, motivation to study, overall school performance) in adolescents? We aimed to identify sleep habits predictors of the quality of school performance in adolescents. Research Methods: Crosssectional analytical study. Data were collected through a self-administered questionnaire with socio-demographic questions, sleep habits and school performance scale. The sample consisted of 380 students between 7th and 9th grade, with an average age of 13.56 ± 1.23 years in the school year 2011/2012, from a 2nd and 3rd Cycle Basic School of the municipality of Viseu, Portugal. Findings: School performance in adolescents was associated with better subjective quality of sleep (p=0.000), with longer sleep duration (p=0.000), with watching tv/video before sleep (p=0.000), with the habit of studying before bedtime (p=0.012), with no computer use (p=0.013) and with reading habits before bed (p=0.000). School performance was also associated with adolescents who reported not feeling sleepy during class. The teenagers who sleep more and better, and who watch tv/video, study, do not use computers, and who read before going to bed, have a better school performance.