246 research outputs found

    Design and analysis of vortex generator for UMP HEV using CFD

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    This thesis is doing vortex generator model with new high to overcome unstable airflow problem in rear car parts. So, with addition vortex generator on rear parts of proton iswara type Hybrid Electrical Vehicle (HEY) will decrease instability air movement on rear car parts. Beside that, addition of vortex generator in rear roof of car is to decrease high pressure and zero velocity area. It is because to make stability of car.Design of vortex generator is done based on shape Proton Iswara vortex generator but only with different high. The vortex generator high is determined based on this study. In this study, 3 velocities (90,100 and 110 km/h) will analyze using cosmosfioworks. Each velocity of car model will analyze with and without vortex generator. Based on this study, addition of vortex generator on rear car able to decrease total area of high pressure and low or zero velocity. This can be seen with decreasing of airflow in the rear car. It is because the vortex generator can be reduce the turbulent boundary layer flow

    Integrated Role of Nutrition and Physical Activity for Lifelong Health

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    As computer and space technologies have been developed, geoscience information systems (GIS) and remote sensing (RS) technologies, which deal with the geospatial information, have been rapidly maturing. Moreover, over the last few decades, machine learning techniques including artificial neural network (ANN), deep learning, decision tree, and support vector machine (SVM) have been successfully applied to geospatial science and engineering research fields. The machine learning techniques have been widely applied to GIS and RS research fields and have recently produced valuable results in the areas of geoscience, environment, natural hazards, and natural resources. This book is a collection representing novel contributions detailing machine learning techniques as applied to geoscience information systems and remote sensing

    Changes in motor competence over four decades in 10 to 14-year-old Austrian boys

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    Background: Data on secular trends in motor competence in children and adolescents has been equivocal. While several studies have shown a decline in motor competence over the last several decades there is also research that showed no change or even an increase in motor competence in youth.Methods: Motor competence was assessed via 6 test items in 10- to 14-year-old Austrian boys in the years 1972, 1987 and 2015. At each measurement time participants performed 20m sprint, 800m run, sit ups, jump and reach, one-leg stand and stand and reach tests in the school gymnasium during regular school time. Data across measurement times was compared using weighted means across 5 age groups with pooled standard deviations.Results: Average performance on the 20m sprint, jump and reach test and one leg stand improved significantly (p<0.05) from 1972 to 2015 by 0.3 seconds, 3.9 cm and 3.5 seconds, respectively. Time for the 800m run increased significantly by 15% (p<0.01), indicating a decline in endurance. Flexibility, measured by the stand and reach test, also declined significantly (p=0.02) from 1972 to 2015. There was no significant difference in the number of sit ups performed at the 3 measurement times. Conclusion: Results of the present study do not show a general decline in motor competence in male middle-school students over the last 4 decades. Rather, secular trends differ by specific components contributing to overall motor competence with declines in flexibility and endurance but increases in power, speed and balance

    Association between 24-h movement guidelines and cardiometabolic health in Chilean adults

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    © The Author(s) 2022. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.This study aimed to examine the association between meeting 24-h movement guidelines and cardiometabolic health in Chilean adults. We used cross-sectional data of 2618 adults from the Chilean National Health Survey 2016-2017. Meeting the 24-h movement guidelines was defined as ≥ 600 MET-min/week of physical activity; ≤ 8 h/day of sitting time; and 7 to 9 h/day of sleep duration. Cardiometabolic health indicators were body mass index, waist circumference, high triglycerides, high blood pressure, type 2 diabetes, metabolic syndrome, and risk of cardiovascular disease in a 10-year period. Meeting none out of three 24-h movement guidelines (vs all three) was associated with higher odds of overweight/obesity (OR 1.67; 95%CI 1.45 to 1.89), high waist circumference (1.65; 1.40 to 1.90), hypertension (2.88; 2.23 to 3.53), type 2 diabetes (1.60; 1.26 to 1.94), metabolic syndrome (1.97; 1.54 to 2.40) and risk of cardiovascular disease (1.50; 1.20, 1.80). Meeting one guideline (vs three) was associated with higher odds of five of out seven cardiometabolic indicators. Our study found that the composition of movement behaviors within a 24-h period may have important implications for cardiometabolic health.info:eu-repo/semantics/publishedVersio

    The Association Between Sedentary Behaviors During Weekdays and Weekend with Change in Body Composition in Young Adults

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    Background: High sedentary time has been considered an important chronic disease risk factor but there is only limited information on the association of specific sedentary behaviors on weekdays and weekend-days with body composition. The present study examines the prospective association of total sedentary time and specific sedentary behaviors during weekdays and the weekend with body composition in young adults. Methods: A total of 332 adults (50% male; 27.7 ±3.7 years) were followed over a period of 1 year. Time spent sedentary, excluding sleep (SED), and in physical activity (PA) during weekdays and weekend-days was objectively assessed every 3 months with a multisensor device over a period of at least 8 days. In addition, participants reported sitting time, TV time and non-work related time spent at the computer separately for weekdays and the weekend. Fat mass and fat free mass were assessed via dual x-ray absorptiometry and used to calculate percent body fat (%BF). Energy intake was estimated based on TDEE and change in body composition. Results: Cross-sectional analyses showed a significant correlation between SED and body composition (0.18 ≤ r ≤ 0.34). Associations between body weight and specific sedentary behaviors were less pronounced and significant during weekdays only (r ≤ 0.16). Nevertheless, decrease in SED during weekends, rather than during weekdays, was significantly associated with subsequent decrease in %BF (β = 0.06, p \u3c0.01). After adjusting for PA and energy intake, results for SED were no longer significant. Only the association between change in sitting time during weekends and subsequent %BF was independent from change in PA or energy intake (β%BF = 0.04, p = 0.01), while there was no significant association between TV or computer time and subsequent body composition. Conclusions: The stronger AIMS Public Health Volume 3, Issue 2, 375-388. prospective association between sedentary behavior during weekends with subsequent body composition emphasizes the importance of leisure time behavior in weight management

    Relation between Physical Fitness Components and the Occurrence and Subjective Intensity of Back Pain in Secondary School Adolescents

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    Despite the well documented benefits of physical fitness (PF) on general health, its role in back pain (BP) is still unclear. The objective of this study was to assess the association between different PF profiles and BP in a sample of adolescents. The study assessed PF and BP in a sample of 919 youth (age = 15.5 ± 1.3 years) from North and South Tyrol. A total of 531 participants (57.8%) reported no BP, whereas 4.7% (n = 43) reported severe BP. A two-step cluster analysis detected three main groups: the “less fit”, with significantly lower scores in all PF tests (p &lt; 0.001); the “strong sprinters”, with higher speed and muscular strength than the others (p &lt; 0.001); and the “flexible marathoners”, with higher flexibility and cardiorespiratory fitness (p &lt; 0.001). The “flexible marathoners” showed significantly better BP scores than the “less fit” (p = 0.029). Cardiorespiratory fitness and trunk flexibility are potential preventive components of BP in adolescents. Since the decline in flexibility starts very early in life, it is recommended to put a particular emphasis on this component of PF. The role of other components of PF should be further investigated in the future

    The Association Between Sedentary Behaviors During Weekdays and Weekend with Change in Body Composition in Young Adults

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    Background: High sedentary time has been considered an important chronic disease risk factor but there is only limited information on the association of specific sedentary behaviors on weekdays and weekend-days with body composition. The present study examines the prospective association of total sedentary time and specific sedentary behaviors during weekdays and the weekend with body composition in young adults. Methods: A total of 332 adults (50% male; 27.7 ±3.7 years) were followed over a period of 1 year. Time spent sedentary, excluding sleep (SED), and in physical activity (PA) during weekdays and weekend-days was objectively assessed every 3 months with a multisensor device over a period of at least 8 days. In addition, participants reported sitting time, TV time and non-work related time spent at the computer separately for weekdays and the weekend. Fat mass and fat free mass were assessed via dual x-ray absorptiometry and used to calculate percent body fat (%BF). Energy intake was estimated based on TDEE and change in body composition. Results: Cross-sectional analyses showed a significant correlation between SED and body composition (0.18 ≤ r ≤ 0.34). Associations between body weight and specific sedentary behaviors were less pronounced and significant during weekdays only (r ≤ 0.16). Nevertheless, decrease in SED during weekends, rather than during weekdays, was significantly associated with subsequent decrease in %BF (β = 0.06, p \u3c0.01). After adjusting for PA and energy intake, results for SED were no longer significant. Only the association between change in sitting time during weekends and subsequent %BF was independent from change in PA or energy intake (β%BF = 0.04, p = 0.01), while there was no significant association between TV or computer time and subsequent body composition. Conclusions: The stronger AIMS Public Health Volume 3, Issue 2, 375-388. prospective association between sedentary behavior during weekends with subsequent body composition emphasizes the importance of leisure time behavior in weight management

    The Association of Physical Activity during Weekdays and Weekend with Body Composition in Young Adults

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    Physical activity (PA) is a key contributor in long-term weight management but there remains limited research on the association between weekly PA patterns and weight change. The purpose of the present study was to examine the prospective association between weekly PA patterns and weight change in generally healthy young adults. Anthropometric measurements, including dual X-ray absorptiometry, were obtained every 3 months over a period of one year in 338 adults (53% male). At each measurement time, participants wore a multisensor device for a minimum of 10 days to determine total daily energy expenditure and time spent sleeping, sedentary, in light PA (LPA), in moderate PA (MPA), and in vigorous PA (VPA). PA did not differ between weekdays and the weekend at baseline. Twenty-four-hour sleep time, however, was significantly longer during weekends compared to weekdays, which was associated with less time spent sedentary. Weight loss was associated with a significant increase in LPA at the expense of sedentary time during the weekend but not during weekdays. Regression analyses further revealed an inverse association between change in VPA during the weekend and body composition at 12-month follow-up. Taken together, these results suggest that weekend PA plays an important role in long-term weight management

    The Association of Physical Activity during Weekdays and Weekend with Body Composition in Young Adults

    Get PDF
    Physical activity (PA) is a key contributor in long-term weight management but there remains limited research on the association between weekly PA patterns and weight change. The purpose of the present study was to examine the prospective association between weekly PA patterns and weight change in generally healthy young adults. Anthropometric measurements, including dual X-ray absorptiometry, were obtained every 3 months over a period of one year in 338 adults (53% male). At each measurement time, participants wore a multisensor device for a minimum of 10 days to determine total daily energy expenditure and time spent sleeping, sedentary, in light PA (LPA), in moderate PA (MPA), and in vigorous PA (VPA). PA did not differ between weekdays and the weekend at baseline. Twenty-four-hour sleep time, however, was significantly longer during weekends compared to weekdays, which was associated with less time spent sedentary. Weight loss was associated with a significant increase in LPA at the expense of sedentary time during the weekend but not during weekdays. Regression analyses further revealed an inverse association between change in VPA during the weekend and body composition at 12-month follow-up. Taken together, these results suggest that weekend PA plays an important role in long-term weight management
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