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The capture of CO 2 by single and mixed alkanolamine solutions of monoethanolamine (MEA), 2-methyl-amino-ethanol (MMEA) and piperazine (PZ) with total alkanolamine concentrations from 30 to 100 wt% was conducted in a rotating packed bed (RPB). The effects of rotational speed, gas flow rate and composition of the absorbent were investigated. Experimental results showed that increasing the alkanolamine concentration and the rotational speed up to 1800 rpm effectively improved the CO 2 removal efficiency. However, the removal efficiency decreased as the gas flow rate increased. MMEA solutions exhibited a higher removal efficiency than MEA because MMEA reacts faster with CO 2 than MEA. The alkanolamines that were mixed with PZ were more effective in capturing CO 2 than single alkanolamine solutions. The height of transfer unit (HTU) decreased as the alkanolamine concentration and rotational speed increased, but increased with the gas flow rate. A CO 2 removal efficiency of 99.4% and an HTU of 0.74 cm were obtained using absorbent that contained 80 wt% MMEA and 20 wt% PZ at a rotational speed of 600 rpm, a liquid flow rate of 0.1 L/min, a gas flow rate of 30 L/min and a temperature of 313 K. The high removal efficiency and low HTU value reveal that an RPB has great potential for CO 2 capture from a gas stream using an absorbent with a high alkanolamine concentration. [ABSTRACT FROM AUTHOR]

Background: Touch screen devices are now ubiquitous, and their usage by young children is increasing. However, the effects of these devices on young children are still unknown. Therefore, this study aimed to address the associations of touch screen device exposure with symptomatic emotional and behavioral problems and language development in children between the ages of 18 and 36 months.Method: A total of 161 primary caregivers of children between the ages of 18 and 36 months were recruited from the pediatric ward and outpatient clinic at a medical center in southern Taiwan. All caregivers were asked to fill out the Child Behavior Checklist for Ages 1½-5 (CBCL 1½-5) and a questionnaire on basic personal information and touch screen device usage, and they were also interviewed with the Communication and Language Screening Test for Birth to Three Chinese-Speaking Infant-Toddlers (CLST). Independent t-test and one-way ANOVA were used to examine the differences among the categories in the demographic variables and to characterize the touch screen device usage behaviors. Pearson's correlation was used to analyze the relationship between language delay and the extent of touch screen device exposure. After primary univariate analysis, we used multiple regression models to examine the relationships among the effects of touch screen device usage behaviors on children's emotional and behavioral problems and language development.Result: The children's mean age was 25.63 months (SD = 5.35). Children who spent more time on touch screen devices were more likely to have emotional problems (β = .219, p < .010, 95 % CI: .279-1.518), anxious/depressive symptoms (β = .206, p < .050, 95 % CI: .170-1.244), somatic complaints (β = .291, p < .001, 95% CI: .455-1.462), social withdrawal symptoms (β = .194, p < .050, 95 % CI: 0.133-1.150), attention problems (β = .300, p < .001, 95 % CI: .432-1.267), and aggressive behaviors (β = .247, p < .010, 95 % CI: .967-3.983). The effects were not noted on language development (β = -.136, p < .100, 95 % CI: -2.595-.147).Conclusion: Young children who spent more time on touch screen devices were more likely to have emotional problems, anxious/depressive symptoms, somatic complaints, social withdrawal symptoms, attention problems, and aggressive behaviors, but not language delay. [ABSTRACT FROM AUTHOR]