21 research outputs found

    Passive Acoustic Emissions in a V-blender

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    The pharmaceutical manufacturing process consists of a number of batch steps; each step must be monitored and controlled to ensure quality standards are met. The development of process analytical technologies (PAT) can improve product monitoring with the aim of increasing efficiency, product quality and consistency and creating a better understanding of the manufacturing process. This work investigates the feasibility of using passive acoustic emissions (PAE) to monitor particulates in a V-blender. An accelerometer was attached to the lid of a V-blender to measure vibrations from the tumbling solids. A wavelet filter removed the oscillations in the signals from the motion of the shell, focusing on the emissions from the particle interactions. The particle size, fill level and scale affected the acoustic emissions through changes in the particle momentum. Changes in particle cohesiveness and flowability were also reflected in the measured emissions. Powder properties and behavior are critical to efficient and successful manufacturing of pharmaceutical tablets. As the powders must be transferred between the different manufacturing stages, the flowability of powders is critical. Trials were conducted to investigate the effect of moisture content of a powder on its flowability. Through avalanche behavior, it was found that the flowability and the dynamic density of a powder change with moisture content. PAEs were used to detect changes in solids moisture content as solids tumbled within the V-blender. It was found that particle mass, coefficient of restitution (COR) and flowability impacted the amplitude of the acoustic emissions. To further investigate the effects of particle flowability, PAEs were used to monitor lubricant addition. The amplitudes of the acoustic emissions were sensitive to the lubricant addition due to changes in the flowability. A trend in the emission amplitude allowed for the progression of the lubricant mixing to be followed. Overall, the research supports the feasibility of PAEs as a PAT for mixing in a tumbling blender to increase process knowledge and improve product quality

    Between-Monitor Differences in Step Counts Are Related to Body Size: Implications for Objective Physical Activity Measurement

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    The quantification of the relationships between walking and health requires that walking is measured accurately. We correlated different measures of step accumulation to body size, overall physical activity level, and glucose regulation.Participants were 25 men and 25 women American Indians without diabetes (Age: 20-34 years) in Phoenix, Arizona, USA. We assessed steps/day during 7 days of free living, simultaneously with three different monitors (Accusplit-AX120, MTI-ActiGraph, and Dynastream-AMP). We assessed total physical activity during free-living with doubly labeled water combined with resting metabolic rate measured by expired gas indirect calorimetry. Glucose tolerance was determined during an oral glucose tolerance test.Based on observed counts in the laboratory, the AMP was the most accurate device, followed by the MTI and the AX120, respectively. The estimated energy cost of 1000 steps per day was lower in the AX120 than the MTI or AMP. The correlation between AX120-assessed steps/day and waist circumference was significantly higher than the correlation between AMP steps and waist circumference. The difference in steps per day between the AX120 and both the AMP and the MTI were significantly related to waist circumference.Between-monitor differences in step counts influence the observed relationship between walking and obesity-related traits

    WalkMore: a randomized controlled trial of pedometer-based interventions differing on intensity messages

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    Pedometer-based programs have elicited increased walking behaviors associated with improvements in blood pressure in sedentary/low active postmenopausal women, a population at increased risk of cardiovascular disease. Such programs typically encourage increasing the volume of physical activity with little regard for its intensity. Recent advances in commercially available pedometer technology now permit tracking of both steps/day and time in moderate (or greater) intensity physical activity on a daily basis. It is not known whether the dual message to increase steps/day while also increasing time spent at higher intensity walking will elicit additional improvements in blood pressure relative to a message to only focus on increasing steps/day. The purpose of this paper is to present the rationale, study design, and protocols employed in WalkMore, a 3-arm 3-month blinded and randomized controlled trial (RCT) designed to compare the effects of two community pedometer-based walking interventions (reflecting these separate and combined messages) relative to a control group on blood pressure in sedentary/low active post-menopausal women, a population at increased risk of cardiovascular disease. 120 sedentary/low active post-menopausal women (45-74 years of age) will be randomly assigned (computer-generated) to 1 of 3 groups: A) 10,000 steps/day (with no guidance on walking intensity/speed/cadence; BASIC intervention, n = 50); B) 10,000 steps/day and at least 30 minutes in moderate intensity (i.e., a cadence of at least 100 steps/min; ENHANCED intervention, n = 50); or a Control group (n = 20). An important strength of the study is the strict control and quantification of the pedometer-based physical activity interventions. The primary outcome is systolic blood pressure. Secondary outcomes include diastolic blood pressure, anthropometric measurements, fasting blood glucose and insulin, flow mediated dilation, gait speed, and accelerometer-determined physical activity and sedentary behavior. This study can make important contributions to our understanding of the relative benefits that walking volume and/or intensity may have on blood pressure in a population at risk of cardiovascular disease. ClinicalTrials.gov Record NCT01519583, January 18, 2012

    Secular trends: a ten-year comparison of the amount and type of physical activity and inactivity of random samples of adolescents in the Czech Republic

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    BACKGROUND: An optimal level of physical activity (PA) in adolescence influences the level of PA in adulthood. Although PA declines with age have been demonstrated repeatedly, few studies have been carried out on secular trends. The present study assessed levels, types and secular trends of PA and sedentary behaviour of a sample of adolescents in the Czech Republic. METHODS: The study comprised two cross-sectional cohorts of adolescents ten years apart. The analysis compared data collected through a week-long monitoring of adolescents' PA in 1998-2000 and 2008-2010. Adolescents wore either Yamax SW-701 or Omron HJ-105 pedometer continuously for 7 days (at least 10 hours per day) excluding sleeping, hygiene and bathing. They also recorded their number of steps per day, the type and duration of PA and sedentary behaviour (in minutes) on record sheets. In total, 902 adolescents (410 boys; 492 girls) aged 14-18 were eligible for analysis. RESULTS: Overweight and obesity in Czech adolescents participating in this study increased from 5.5% (older cohort, 1998-2000) to 10.4% (younger cohort, 2008-2010). There were no inter-cohort significant changes in the total amount of sedentary behaviour in boys. However in girls, on weekdays, there was a significant increase in the total duration of sedentary behaviour of the younger cohort (2008-2010) compared with the older one (1998-2000). Studying and screen time (television and computer) were among the main sedentary behaviours in Czech adolescents. The types of sedentary behaviour also changed: watching TV (1998-2000) was replaced by time spent on computers (2008-2010).The Czech health-related criterion (achieving 11,000 steps per day) decreased only in boys from 68% (1998-2000) to 55% (2008-2010). Across both genders, 55%-75% of Czech adolescents met the health-related criterion of recommended steps per day, however less participants in the younger cohort (2008-2010) met this criterion than in the older cohort (1998-2000) ten years ago. Adolescents' PA levels for the monitored periods of 1998-2000 and 2008-2010 suggest a secular decrease in the weekly number of steps achieved by adolescent boys and girls. CONCLUSION: In the younger cohort (2008-2010), every tenth adolescent was either overweight or obese; roughly twice the rate when compared to the older cohort (1998-2000). Sedentary behaviour seems relatively stable across the two cohorts as the increased time that the younger cohort (2008-2010) spent on computers is compensated with an equally decreased time spent watching TV or studying. Across both cohorts about half to three quarters of the adolescents met the health-related criterion for achieved number of steps. The findings show a secular decrease in PA amongst adolescents. The significant interaction effects (cohort × age; and cohort × gender) that this study found suggested that secular trends in PA differ by age and gender

    The influence of schooling on the stability and mutability of gender attitudes: Findings from a longitudinal study of adolescent girls in Zambia

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    Purpose: Inequitable gender norms are thought to harm lifelong health and well-being. We explore the process of gender attitude change and the role of schooling in shifting or reinforcing gender norms among adolescent girls in Zambia. Methods: We used longitudinal data collected from unmarried, vulnerable girls (aged 10–19 years) as part of the Adolescent Girls Empowerment Program. We conducted random effects multinomial logistic regression to determine whether schooling-related factors were associated with shifts in adolescent girls\u27 gender attitudes across three survey rounds and explored whether these relationships varied by age. Results: Mean gender attitude scores at the aggregate level remained stable over time among rural girls and improved slightly for urban girls. At the individual level, about half the girls had relatively unchanged scores, whereas the other half shifted to higher or lower scores between rounds. Rural and urban girls currently attending school were more likely to have relatively stable equitable attitudes than stable, inequitable attitudes, or attitudes that shifted to inequitable. Educational attainment was not associated with shifts in gender attitudes among rural girls. Urban girls with higher educational attainment were more likely to have relatively stable equitable attitudes than stable, inequitable attitudes, or attitudes that shifted to inequitable or more equitable. Conclusions: Patterns of gender attitude stability and change differed more for urban girls than rural girls and varied by age and schooling-related factors. In general, schooling appears to be an institutional lever that holds promise for shifting gender attitudes toward greater equality. Our study highlights the importance of looking longitudinally at the effects of social context and reinforces calls for targeted, context-specific interventions for this age group
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