Search results for "multi-stage"
showing 10 items of 15 documents
Novel solutions for closed-loop Reverse Electrodialysis: thermodynamic characterisation and perspective analysis
2019
Abstract Closed-loop Reverse Electrodialysis is a novel technology to directly convert low-grade heat into electricity. It consists of a reverse electrodialysis (RED) unit where electricity is produced exploiting the salinity gradient between two salt-water solutions, coupled with a regeneration unit where waste-heat is used to treat the solutions exiting from the RED unit and restore their initial composition. One of the most important advantages of closed-loop systems compared to the open systems is the possibility to select ad-hoc salt solutions to achieve high efficiencies. Therefore, the properties of the salt solutions are essential to assess the performance of the energy generation a…
Thermodynamic characterisation of novel solutions for closed-loop reverse electrodialysis
2018
Closed-loop reverse electrodialysis is a novel technology to convert low-grade heat directly into electricity. It consists of a reverse electrodialysis unit coupled with a regeneration unit in which the waste-heat is used to restore the initial conditions of the two solutions. One of the most impor- tant advantages of closed-loop system is the possibility to select an ad-hoc salt solution to obtain high efficiency. In this regard, it is important to assess how the salt solution properties affect the performance of the energy generation and solution regeneration processes. The aim of this study is to analyse the effect of thermodynamic properties of non-conventional salt solutions within a R…
Energy saving with MSF-RO series desalination plants
2003
Two major techniques are commercially used in different parts of the world: distillation and membrane processes. The dominant distillation process is multi-stage flash (MSF), and the main membrane process is reverse osmosis (RO). Although cost factors vary by site, the total cost of producing potable water from seawater with the RO process is today usually less than thermal desalting processes and the economic advantages of RO vs. evaporation process, such as MSF, are responsible for the rapid increase in use of seawater RO. In many countries both RO and MSF processes are operating. Reduction in product water cost could be achieved when a hybrid MSF-RO system is used, instead of a parallel …
Physical fitness of individuals with intellectual disability who have special olympics experience
2016
Physical fitness of individuals with intellectual disability (ID) is low compared to those without ID. Part of the mission of Special Olympics is to develop physical fitness. However, little is known about fitness levels of Special Olympics athletes. This study examined the fitness level of individuals who participated in Nordic Special Olympics Games 2008 in Finland. The sample consisted of 59 Special Olympics athletes (44 men, 15 women, age 16–45) whose fitness scores were compared to INAS-athletes (International Association of Sport for para-athletes with ID) and Finnish non-athletic individuals with ID. The fitness battery consisted of 8 items: BMI, sit-and-reach test, stork stand, sit …
Motor competence, perceived physical competence, physical fitness, and physical activity within Finnish children
2019
The purpose of this study was to investigate reciprocal relationships among students’ motor competence (MC) (leaping, throwing, catching, jumping skills), perceived physical competence, health‐related fitness (HRF) (20 m shuttle run, push‐up, abdominal muscles endurance tests) and objectively measured moderate‐to‐vigorous physical activity (MVPA). Participants included 422 Grade 5 Finnish children (246 girls). Two separate structural equation models investigated paths (a) from MC through both perceived physical competence and HRF to MVPA, and (b) from MVPA through both perceived physical competence and HRF to MC. Model 1 demonstrated an indirect path from MC through HRF to MVPA and a direct…
Adiposity, physical activity and neuromuscular performance in children
2016
We investigated the associations of body fat percentage, objectively assessed moderate-to-vigorous physical activity (MVPA), and different types of physical activity assessed by a questionnaire with neuromuscular performance. The participants were 404 children aged 6–8 years. Body fat percentage (BF%) was assessed using dual-energy x-ray absorptiometry and physical activity by combined heart rate and movement sensing and a questionnaire. The results of 50-metre shuttle run, 15-metre sprint run, hand grip strength, standing long jump, sit-up, modified flamingo balance, box and block, and sit-and-reach tests were used as measures of neuromuscular performance. Children who had a combination of…
Physical fitness development in relation to changes in body composition and physical activity in adolescence
2020
The decline in adolescents’ physical fitness (PF) in recent decades has raised concerns about current population’s possible future challenges with health and physical functional capacity. This study explored the associations between body composition, physical activity, maturation, and PF development in adolescents. Furthermore, PF development of adolescents with low initial PF was assessed. A 2‐year observational study was conducted between spring 2013 and 2015. Nine comprehensive schools and their 10‐ to 13‐year‐old students were invited to participate in the study (1778), and a total of 971 students (54.6%) agreed. Cardiorespiratory fitness (20‐metre shuttle run), muscular fitness (push‐u…
Effects of a Physical Activity Intervention on Physical Fitness of schoolchildren: The Enriched Sport Activity Program
2020
Background: Physical fitness in youth is a predictor of health in adulthood. The main objective of the present study was to understand if an enriched sport activity program could increase physical fitness in a population of schoolchildren. Methods: In a sample of 672 children aged 10.0 ±
Longitudinal Associations of Fitness, Motor Competence, and Adiposity with Cognition
2019
Purpose: The purpose of this study was to investigate the longitudinal associations of cardiorespiratory fitness (CRF), motor competence (MC), and body fat percentage (BF%) with cognition in children. Methods: Altogether, 371 children (188 boys and 183 girls) 6–9 yr of age at baseline participated in this 2-yr follow-up study. We assessed CRF by maximal cycle ergometer test, computed the MC score from the z-scores of the 50-m shuttle run, static balance, and box and block test results, measured BF% by dual-energy x-ray absorptiometry, and assessed cognition using the Raven’s Coloured Progressive Matrices (RCPM) score. The associations were studied by linear regression analysis and repeated-…
Physical activity, aerobic fitness, and brain white matter : Their role for executive functions in adolescence
2020
Highlights • Aerobic fitness level, but not physical activity, is related to white matter properties in the brain. • The relation between physical activity and working memory is moderated by fractional anisotropy (FA) of the corpus callosum. • The FA of the corpus callosum and superior corona radiata moderates the relation between aerobic fitness and working memory.