40 research outputs found

    Body mass index, nutrition and parental migration : from birth to adolescence

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    Childhood overweight and obesity is a major public health problem of the recent century. The aim of this thesis was to investigate the impact of parental migration background on childhood overweight and obesity and lifestyle in relation to socioeconomic position, and the possible role of factors such as perinatal characteristics and breastfeeding in BMI development among offspring of immigrant parents. The relation between parental migration background and risk of childhood overweight and obesity was studied among 2 589 children of a Swedish birth cohort (BAMSE) where 22 % (n = 561) had at least one foreign-born parent (Study I). At age 8 years, 20 % of children with native Swedish parents and 26 % of children with at least one foreign-born parent were overweight or obese. In a multivariate logistic model, adjusting for parental education, physical activity and compliance with nutritional recommendation, children of immigrant parents had 33 % higher odds of overweight and obesity compared with Swedish peers. When both parents were immigrants, the number increased to 70 %. Offspring of parents from Latin America and Asia had significantly higher odds of overweight and obesity than Swedish peers. In the same population, we studied the association between parental migration background and risk of low physical activity among offspring (Study I). Controlling for parental education, overweight and compliance with nutritional recommendations, offspring of immigrant parents had 30 % higher odds of low physical activity than Swedish peers. The odds increased to 67 % when both parents were immigrants. Moreover, low parental education was associated with low levels of physical activity, regardless of parental migration background. The relation between parental migration background and compliance with nutritional recommendations was also studied in Study I. The compliance with nutritional recommendations was assessed using a scoring model which estimated the average fulfillment of nutritional recommendations. Compliance with nutritional recommendations among offspring of immigrant parents was better than among Swedish peers. In subgroups, only children with an immigrant father showed better compliance. Higher consumption of fruit and vegetables and unprocessed meats were healthy aspects of diet among children of immigrant parents, opposed by unhealthy aspects such as low consumption of milk and dairy and high consumption of sweets. Furthermore, high parental education was associated with a high dietary score, regardless of parental migration background. The relation between maternal migration background, perinatal characteristics, and BMI development was studied in a longitudinal follow-up from birth to age 12 years in Study II. There were no significant differences in pregnancy outcome with regard to birth weight and weight for gestational age between offspring of immigrant vs. Swedish mothers. However, BMI development was different in the two groups adjusting for maternal and perinatal characteristics. Children of immigrant mothers had a slower BMI development than Swedish peers up to age 5 years, followed by a steeper pattern afterward. The relation between maternal migration background and duration of breastfeeding, and BMI development was evaluated in a longitudinal study from age 2 to 16 years (Study III). Comparing children breastfed for short periods or not at all with exclusively breastfed ones, a steeper BMI development was observed among offspring of Swedish mothers but the opposite was observed among offspring of immigrant mothers. The observed variations in BMI development patterns were compatible with ages at adiposity rebound. In conclusion the results of this thesis underline the risk gradient for childhood overweight and obesity, and adverse lifestyles among Swedish born children with immigrant parents. This thesis also demonstrates diverse patterns in BMI development by parental migration background which starts at early childhood. However, the diversities in risk of overweight and obesity, and also BMI development was not fully explained by parental education as indicator of socioeconomic position, perinatal characteristics and duration of breastfeeding. More studies are needed to explore underlying driving forces and their possible interaction with regards to parental lifestyles, cultural background, and different indicators of socioeconomic position, psychosocial environment and acculturation

    Reliability, Validity, and Factorial Analysis of a Short Version of the Self-Regulation Inventory

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    AbstractThe study examined psychometric properties of a short version of the Self-Regulation Inventory (SRI-S) including reliability, validity, and exploratory factor analysis of the SRI-S in an Iranian students. Six hundred and seventy six Iranian volunteers (294 \males, 382 females) from universities in Iran were included in this study. All participants were asked to complete the SRI-S (Marques, Ibanez, Ruiperez, Moya, & Ortet, 2005), the Eysenck Personality Questionnaire-Revised Short Scale (EPQ-RS; Eysenck, Eysenck, & Barrett, 1985), and the Mental Health Inventory (MHI-28; Besharat, 2009). The results of explarotary factor analysis supported a single general factor of self-regulation and a five factor structure including Positive Actions, Controllability, Expression of Feelings and Needs, Assertiveness, and Well-Being Seeking. The convergent and discriminant validity of the SRI-S were supported by an expected pattern of correlations between the scale and the measures of personality and mental health. All correlation coefficients between the mean scores on the SRI-S and scores of the extraversion, neuroticism, psychological well-being, and psychological distress were statistically significant

    Effect of a commercial air valve on the rapid filling of a single pipeline: a numerical and experimental analysis

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    [EN] The filling process in water pipelines produces pressure surges caused by the compression of air pockets. In this sense, air valves should be appropriately designed to expel sufficient air to avoid pipeline failure. Recent studies concerning filling maneuvers have been addressed without considering the behavior of air valves. This work shows a mathematical model developed by the authors which is capable of simulating the main hydraulic and thermodynamic variables during filling operations under the effect of the air valve in a single pipeline, which is based on the mass oscillation equation, the air¿water interface, the polytropic equation of the air phase, the air mass equation, and the air valve characterization. The mathematical model is validated in a 7.3-m-long pipeline with a 63-mm nominal diameter. A commercial air valve is positioned in the highest point of the hydraulic installation. Measurements indicate that the mathematical model can be used to simulate this phenomenon by providing good accuracy.This work is supported by Fundacao para a Ciencia e Tecnologia (FCT), Portugal (grant number PD/BD/114459/2016).Coronado-Hernández, OE.; Besharat, M.; Fuertes-Miquel, VS.; Ramos, HM. (2019). Effect of a commercial air valve on the rapid filling of a single pipeline: a numerical and experimental analysis. Water. 11(9):1-13. https://doi.org/10.3390/w11091814S11311

    Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves

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    The emptying procedure is a common operation that engineers have to face in pipelines. This generates subatmospheric pressure caused by the expansion of air pockets, which can produce the collapse of the system depending on the conditions of the installation. To avoid this problem, engineers have to install air valves in pipelines. However, if air valves are not adequately designed, then the risk in pipelines continues. In this research, a mathematical model is developed to simulate an emptying process in pipelines that can be used for planning this type of operation. The one-dimensional proposed model analyzes the water phase propagation by a new rigid model and the air pockets effect using thermodynamic formulations. The proposed model is validated through measurements of the air pocket absolute pressure, the water velocity and the length of the emptying columns in an experimental facility. Results show that the proposed model can accurately predict the hydraulic characteristic variables.The authors acknowledge: (1) the financial support for the first author covered by Fundacion Centro de Estudios Interdisciplinarios Basicos y Aplicados (CEIBA)-Gobernacion de Bolivar (Colombia); and (2) the experimental facilities for conducting the tests provided by IST (Instituto Superior Tecnico), Civil Engineering Research and Innovation for Sustainability (CERIS), of the University of Lisbon (Portugal).Coronado-Hernández, OE.; Vicente S. Fuertes-Miquel; Besharat, M.; Ramos, HM. (2017). Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves. Water. 9(2):1-15. doi:10.3390/w9020098S1159

    Computational fluid dynamics for sub-atmospheric pressure analysis in pipe drainage

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    [EN] The occurrence of sub-atmospheric pressure in the drainage of pipelines containing an air pocket has been known as a major cause of several serious problems. Accordingly, some system malfunction and pipe buckling events have been reported in the literature. This case has been studied experimentally and numerically in the current research considering objectives for a better understanding of: (i) the emptying process, (ii) the main parameters influencing the drainage, and (iii) the air-water interface deformation. Also, this research demonstrates the ability of a computational fluid dynamic (CFD) model in the simulation of this event. The effects of the air pocket size, the percentage and the time of valve opening on the pressure variation have been studied. Results show the pipeline drainage mostly occurs due to backflow air intrusion. The worst case scenario is associated with a fast valve opening when a tiny air pocket exists in the pipeline.This work is supported by Fundacao para a Ciencia e Tecnologia (FCT), Portugal [grant number PD/BD/114459/2016].Besharat, M.; Coronado-Hernández, OE.; Fuertes-Miquel, VS.; Viseu, MT.; Ramos, HM. (2019). Computational fluid dynamics for sub-atmospheric pressure analysis in pipe drainage. Journal of Hydraulic Research. 58(4):553-565. https://doi.org/10.1080/00221686.2019.1625819S553565584ANSYS FLUENT R19.0 academic [Computer software]. ANSYS, Canonsburg, PA. Retrieved from https://www.ansys.com/academic/free-student-productsApollonio, C., Balacco, G., Fontana, N., Giugni, M., Marini, G., & Piccinni, A. (2016). Hydraulic Transients Caused by Air Expulsion During Rapid Filling of Undulating Pipelines. Water, 8(1), 25. doi:10.3390/w8010025Benjamin, T. B. (1968). Gravity currents and related phenomena. Journal of Fluid Mechanics, 31(2), 209-248. doi:10.1017/s0022112068000133Besharat, M., Coronado-Hernández, O. E., Fuertes-Miquel, V. S., Viseu, M. T., & Ramos, H. M. (2018). Backflow air and pressure analysis in emptying a pipeline containing an entrapped air pocket. Urban Water Journal, 15(8), 769-779. doi:10.1080/1573062x.2018.1540711Besharat, M., Tarinejad, R., Aalami, M. T., & Ramos, H. M. (2016). Study of a Compressed Air Vessel for Controlling the Pressure Surge in Water Networks: CFD and Experimental Analysis. Water Resources Management, 30(8), 2687-2702. doi:10.1007/s11269-016-1310-1Besharat, M., Tarinejad, R., & Ramos, H. M. (2015). The effect of water hammer on a confined air pocket towards flow energy storage system. Journal of Water Supply: Research and Technology-Aqua, 65(2), 116-126. doi:10.2166/aqua.2015.081Besharat, M., Teresa Viseu, M., & Ramos, H. (2017). Experimental Study of Air Vessel Behavior for Energy Storage or System Protection in Water Hammer Events. Water, 9(1), 63. doi:10.3390/w9010063Collins, R. P., Boxall, J. B., Karney, B. W., Brunone, B., & Meniconi, S. (2012). How severe can transients be after a sudden depressurization? Journal - American Water Works Association, 104(4), E243-E251. doi:10.5942/jawwa.2012.104.0055Coronado-Hernández, O., Fuertes-Miquel, V., Besharat, M., & Ramos, H. (2017). Experimental and Numerical Analysis of a Water Emptying Pipeline Using Different Air Valves. Water, 9(2), 98. doi:10.3390/w9020098Coronado-Hernández, O. E., Fuertes-Miquel, V. S., Besharat, M., & Ramos, H. M. (2018). Subatmospheric pressure in a water draining pipeline with an air pocket. Urban Water Journal, 15(4), 346-352. doi:10.1080/1573062x.2018.1475578Coronado-Hernández, O. E., Fuertes-Miquel, V. S., Iglesias-Rey, P. L., & Martínez-Solano, F. J. (2018). Rigid Water Column Model for Simulating the Emptying Process in a Pipeline Using Pressurized Air. Journal of Hydraulic Engineering, 144(4), 06018004. doi:10.1061/(asce)hy.1943-7900.0001446Ding, H., Visser, F. C., Jiang, Y., & Furmanczyk, M. (2011). Demonstration and Validation of a 3D CFD Simulation Tool Predicting Pump Performance and Cavitation for Industrial Applications. Journal of Fluids Engineering, 133(1). doi:10.1115/1.4003196Fuertes-Miquel, V. S., Coronado-Hernández, O. E., Iglesias-Rey, P. L., & Mora-Meliá, D. (2018). Transient phenomena during the emptying process of a single pipe with water–air interaction. Journal of Hydraulic Research, 57(3), 318-326. doi:10.1080/00221686.2018.1492465Izquierdo, J., Fuertes, V. S., Cabrera, E., Iglesias, P. L., & Garcia-Serra, J. (1999). Pipeline start-up with entrapped air. Journal of Hydraulic Research, 37(5), 579-590. doi:10.1080/00221689909498518Laanearu, J., Annus, I., Koppel, T., Bergant, A., Vučković, S., Hou, Q., … van’t Westende, J. M. C. (2012). Emptying of Large-Scale Pipeline by Pressurized Air. Journal of Hydraulic Engineering, 138(12), 1090-1100. doi:10.1061/(asce)hy.1943-7900.0000631Liu, D., & Zhou, L. (2009). Numerical Simulation of Transient Flow in Pressurized Water Pipeline with Trapped Air Mass. 2009 Asia-Pacific Power and Energy Engineering Conference. doi:10.1109/appeec.2009.4918544Martinoia, T., Barreto, C. V., da Rocha, J. C. D. C., Lavoura, J., & Henriques, F. M. P. (2012). Simulation and Planning of Pipeline Emptying Operations. Volume 1: Upstream Pipelines; Project Management; Design and Construction; Environment; Facilities Integrity Management; Operations and Maintenance; Pipeline Automation and Measurement. doi:10.1115/ipc2012-90432Martins, N. M. C., Delgado, J. N., Ramos, H. M., & Covas, D. I. C. (2017). Maximum transient pressures in a rapidly filling pipeline with entrapped air using a CFD model. Journal of Hydraulic Research, 55(4), 506-519. doi:10.1080/00221686.2016.1275046Tijsseling, A. S., Hou, Q., Bozkuş, Z., & Laanearu, J. (2015). Improved One-Dimensional Models for Rapid Emptying and Filling of Pipelines. Journal of Pressure Vessel Technology, 138(3). doi:10.1115/1.4031508Trindade, B. C., & Vasconcelos, J. G. (2013). Modeling of Water Pipeline Filling Events Accounting for Air Phase Interactions. Journal of Hydraulic Engineering, 139(9), 921-934. doi:10.1061/(asce)hy.1943-7900.0000757Vasconcelos, J. G., & Wright, S. J. (2008). Rapid Flow Startup in Filled Horizontal Pipelines. Journal of Hydraulic Engineering, 134(7), 984-992. doi:10.1061/(asce)0733-9429(2008)134:7(984)Wang, L., Wang, F., Karney, B., & Malekpour, A. (2017). Numerical investigation of rapid filling in bypass pipelines. Journal of Hydraulic Research, 55(5), 647-656. doi:10.1080/00221686.2017.1300193Zhou, L., & Liu, D. (2013). Experimental investigation of entrapped air pocket in a partially full water pipe. Journal of Hydraulic Research, 51(4), 469-474. doi:10.1080/00221686.2013.785985Zhou, L., Liu, D., Karney, B., & Wang, P. (2013). Phenomenon of White Mist in Pipelines Rapidly Filling with Water with Entrapped Air Pockets. Journal of Hydraulic Engineering, 139(10), 1041-1051. doi:10.1061/(asce)hy.1943-7900.0000765Zhou, L., Liu, D., & Karney, B. (2013). Investigation of Hydraulic Transients of Two Entrapped Air Pockets in a Water Pipeline. Journal of Hydraulic Engineering, 139(9), 949-959. doi:10.1061/(asce)hy.1943-7900.0000750Zhou, L., Liu, D., Karney, B., & Zhang, Q. (2011). Influence of Entrapped Air Pockets on Hydraulic Transients in Water Pipelines. Journal of Hydraulic Engineering, 137(12), 1686-1692. doi:10.1061/(asce)hy.1943-7900.0000460Zhou, L., Liu, D., & Ou, C. (2011). Simulation of Flow Transients in a Water Filling Pipe Containing Entrapped Air Pocket with VOF Model. Engineering Applications of Computational Fluid Mechanics, 5(1), 127-140. doi:10.1080/19942060.2011.11015357Zukoski, E. E. (1966). Influence of viscosity, surface tension, and inclination angle on motion of long bubbles in closed tubes. Journal of Fluid Mechanics, 25(4), 821-837. doi:10.1017/s002211206600044

    Effect of Parental Migration Background on Childhood Nutrition, Physical Activity, and Body Mass Index

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    Background. Poor nutrition, lack of physical activity, and obesity in children have important public health implications but, to date, their effects have not been studied in the growing population of children in Sweden with immigrant parents. Methods. We estimated the association between parental migration background and nutrition, physical activity, and weight in 8-year-old children born in Stockholm between 1994 and 1996 of immigrants and Swedish parents (n=2589). Data were collected through clinical examination and questionnaires filled out by parents. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated using multivariable logistic regression. Results. Children of immigrants complied more closely with Nordic Nutrition Recommendations compared with those of Swedes (OR = 1.35, 95% CI 1.11–1.64). They had higher intake of dietary fibre, vitamins C, B6, and E, folic acid, and polyunsaturated fatty acids (omega-3 and omega-6) reflecting higher consumption of foods of plant origin, but lower intake of vitamins A and D, calcium, and iron reflecting lower consumption of dairy products. Children of immigrants had higher intake of sucrose reflecting higher consumption of sugar and sweets. Furthermore, these children had a higher risk of having low physical activity (OR = 1.31, 95% CI 1.06–1.62) and being overweight (OR = 1.33, 95% CI 1.06–1.65) compared with children of Swedish parents. The odds of having low physical activity and being overweight were even higher in children whose parents were both immigrants. A low level of parental education was associated with increased risk of low physical activity regardless of immigration background. Conclusions. Culturally appropriate tools to capture the diverse range of ethnic foods and other lifestyle habits are needed. Healthcare professionals should be aware of the low levels of physical activity, increased weight, and lack of consumption of some important vitamins among children of immigrants

    Application of Newton–Raphson Method for Computing the Final Air–Water Interface Location in a Pipe Water Filling

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    The estimation of thermodynamic behavior during filling processes with entrapped air in water pipelines is a complex task as it requires solving a system of algebraic-differential equations. A lot of different numerical methods have been used for this purpose in literature including the rigid water column (RWC) model. The main advantage of the RWC model is its acceptable accuracy with very low computational load. In that context, this research presents the computation of critical points of the physical equations that describe the phenomenon. These points provide information about the final position of the air–water interface. The Newton–Raphson method was then applied to obtain a unique equation that can be used by engineers to directly compute variables such as air pocket pressure and water column length at the end of the hydraulic event. A case study was analyzed to compare the results of the mathematical model with the obtained equation for computing critical points. Both methods provided the same values for the water column length at the end of the hydraulic event. A sensitivity analysis was conducted to identify dependent and non-dependent parameters for evaluating the critical points. The proposed formulation was validated through an experimental set of data. © 2023 by the authors

    Concerning dynamic effects in pipe systems with two-phase flows: pressure surges, cavitation and ventilation

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    [EN] The risks associated with unsteady two-phase flows in pressurized pipe systems must be considered both in system design and operation. To this end, this paper summarizes experimental tests and numerical analyses that highlight key aspects of unsteady two-phase flows in water pipelines. The essential dynamics of air¿water interactions in unvented lines are first considered, followed by a summary of how system dynamics change when air venting is provided. System behaviour during unsteady two-phase flows is shown to be counter-intuitive, surprising, and complex. The role of air valves as protection devices is considered as is the reasonableness of the usual assumptions regarding air valve behaviour. The paper then numerically clarifies the relevance of cavitation and air valve performance to both the predicted air exchanges through any installed air valves and their role in modifying system behaviour during unsteady flows.This work was supported by Fundacao para a Ciencia e a Tecnologia [grant number SFRH/BD/39502/2007]. This study was financed in part by the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brasil (CAPES)-Finance Code 001.Ramos, HM.; Fuertes-Miquel, VS.; Tasca, E.; Coronado-Hernández, OE.; Besharat, M.; Zhou, L.; Karney, B. (2022). Concerning dynamic effects in pipe systems with two-phase flows: pressure surges, cavitation and ventilation. Water. 14(15):1-23. https://doi.org/10.3390/w14152376123141

    Numerical model of the water pipe filling with an air valve

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    [EN] Water filling processes in pipes generate overpressures that must be considered so that the facilities do not fail during their operation. The filling manoeuvres with air trapped in water pipes have been studied by different authors. However, these investigations do not consider the behaviour of the air valves, which act as surge protection devices reducing the overpressures caused. This paper presents the mathematical model developed to simulate the hydraulic and thermodynamic variables that affect the process of filling water with air valves in simple pipes. A water pipe facility with a length of 7.3 m, a nominal diameter of 63 mm and an air valve installed at the highest point has been used to collect data for the validation of the mathematical model.[ES] Los procesos de llenado de agua en conducciones generan sobrepresiones que deben considerarse para que las instalaciones no fallen durante su operación. Las maniobras de llenado con aire atrapado en conducciones de agua han sido estudiadas por distintos autores. No obstante, estas investigaciones no consideran el comportamiento de las válvulas aire, las cuales actúan como dispositivos de protección reduciendo las sobrepresiones ocasionadas. En este trabajo se presenta el modelo matemático desarrollado para simular las variables hidráulicas y termodinámicas que intervienen durante el proceso de llenado de agua con válvulas de aire en tuberías simples. Para la validación del modelo matemático se ha utilizado una instalación con una longitud de 7.3 m y un diámetro nominal de 63 mm, y en donde se ha instalado una ventosa de referencia S050 (A.R.I.) en el punto más alto.Coronado-Hernández, OE.; Fuertes-Miquel, VS.; Besharat, M.; Ramos, HM. (2019). Modelo numérico del proceso de llenado de una conducción simple con válvula de aire. Revista Recursos Hídricos. 40(2):19-25. https://doi.org/10.5894/rh40n2-cti2S192540

    Three-dimensional analysis of air-admission orifices in pipelines during hydraulic drainage events

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    [EN] Air valves operate as protection devices in pipelines during drainage processes in order to mitigate vacuum pressures and control the transient flows. Currently, different authors have proposed one-dimensional models to predict the behaviour of orifices during filling and draining events, which offer good numerical results. However, the three-dimensional dynamic behaviour of air-admission orifices during drainage processes has not been studied in depth in the literature. In this research, the effects of air inflow on an orifice installed in a single pipe during drainage events are analysed using a three-dimensional computational fluid dynamics model by testing orifices with diameters of 1.5 and 3.0 mm. This model was validated with different experimental measurements associated to the vacuum pressure, obtaining good fits. The three-dimensional model predicts additional information associated to the aerodynamic effects that occur during the air-admission processes, which is studied. Subsonic flows are observed in different orifices with Mach numbers between 0.18 and 0.30. In addition, it is shown that the larger-diameter orifice ensures a more effective airflow control compared to the smaller-diameter orifice.This research was funded by grant No. INV03CI2214 of the Universidad Tecnologica de Bolivar.Paternina-Verona, DA.; Coronado-Hernández, OE.; Espinoza-Román, HG.; Besharat, M.; Fuertes-Miquel, VS.; Ramos, HM. (2022). Three-dimensional analysis of air-admission orifices in pipelines during hydraulic drainage events. Sustainability. 14(21):1-14. https://doi.org/10.3390/su142114600114142
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