RESUMEN
Understanding changes in thermodynamic and transport properties during adsorption is crucial for the thermal management of metal-organic frameworks, which also imposes significant challenges for improved performance and energy density of adsorption system. Because of phase transitions in the intermolecular interactions involved in the adsorption phenomena, transport properties including the thermal conductivity exhibit interesting behaviors, yet fully understood. This study employs detailed molecular dynamics simulations to replicate the methane/Cu-BTC adsorption phenomenon for the evaluation of their thermal conductivities across different pressures and temperatures. The molecular simulations show that the thermal conductivities of both the adsorbent (Cu-BTC) and adsorbate (methane, adsorbed phase) vary notably during adsorption processes. Using the concepts of the change in the degree of free movements of the adsorbate molecules and atomic vibration of adsorbent, the reduction of the adsorbate thermal conductivity (â¼70-93%) and increase thermal conductivity of the adsorbent (up to 3 times) in Cu-BTC+CH4 pair are explained.
RESUMEN
Objectives@#To estimate the frequency of Metabolic Syndrome (MS in Myanmar obese children and to determine the risk factors associated with MS in obese children comparing with normal weight children. @*Methodology@#A cross-sectional study was conducted to compare the risk factors for metabolic syndrome between normal and obese children by using the pediatric definition for metabolic syndrome [International Diabetes Federation (IDF), 2007]. Twenty-three obese children (BMI, ≥ 97th percentile) and 23 normal weight children (BMI, < 85th percentile) aged 5-12 years were included in the study. Blood pressure, body weight, height, waist circumference (WC), fasting triglycerides, HDL-cholesterol, total cholesterol and glucose concentrations were determined. @*Results@#Based on the IDF pediatric criteria, 9 obese children (39.1%) had metabolic syndrome while no normal weight child had metabolic syndrome. Ten (43.5%) normal weight children and 3 (13.0%) obese children had at least one risk factor for the metabolic syndrome. Central obesity (WC ³ 90th percentile for age and sex), the most common risk factor, was observed in 25 children (54.4% of the total population). @*Conclusion@#This study highlights the need for early recognition of risk factors for metabolic syndrome in all children to halt the progression of type 2 diabetes and cardiovascular diseases (CVD) in later life.