Fluid mechanical peristaltic transport through esophagus is studied in the paper. A mathematical model has been developed to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube le...Fluid mechanical peristaltic transport through esophagus is studied in the paper. A mathematical model has been developed to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of a viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed specifically to explore some important information concerning the movement of food bolus through esophagus. The analysis is carried out by using the lubrication theory. The study is particularly suitable for the cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes place by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocities, particle trajectory, and reflux is investigated for a single wave as well as a train of periodic peristaltic waves. The locally variable pressure is seen to be highly sensitive to the flow index ＂n＂. The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus.展开更多
Objective:To investigate the possible mechanisms of the decreasing fluid and food consumption following Hibiscus sabdariffa(HS) consumption.Methods:On the 1st day of pregnancy,rats were randomly divided into three gro...Objective:To investigate the possible mechanisms of the decreasing fluid and food consumption following Hibiscus sabdariffa(HS) consumption.Methods:On the 1st day of pregnancy,rats were randomly divided into three groups with six animals per each group.One group was given tap water,one was given with extract at 0.6 g/100 mL while the third group was given with extract at 1.8 g/100 mL as their drinking solution.All groups received normal rat chow and drinking solution ad libitum.Fluid& food intake and weight were measured daily throughout pregnancy and Na^+ concentration in plasma was determined on the 18th day of pregnancy.Results:Results showed decreased fluid and food consumption,decreased weight gain and increased sodium ion concentration in plasma of rats with HS extract compared with the control group.Conclusions: Consumption of aqueous extract of the calyx of HS during pregnancy decreases food consumption and weight gain through mechanisms that may depend on Na^+ in HS content and elevating Na^+ concentration.展开更多
基金the Council of Scientific and Industrial Research (CSIR) of New Delhi for awarding him a scientific research fund
文摘Fluid mechanical peristaltic transport through esophagus is studied in the paper. A mathematical model has been developed to study the peristaltic transport of a rheological fluid for arbitrary wave shapes and tube lengths. The Ostwald-de Waele power law of a viscous fluid is considered here to depict the non-Newtonian behaviour of the fluid. The model is formulated and analyzed specifically to explore some important information concerning the movement of food bolus through esophagus. The analysis is carried out by using the lubrication theory. The study is particularly suitable for the cases where the Reynolds number is small. The esophagus is treated as a circular tube through which the transport of food bolus takes place by periodic contraction of the esophageal wall. Variation of different variables concerned with the transport phenomena such as pressure, flow velocities, particle trajectory, and reflux is investigated for a single wave as well as a train of periodic peristaltic waves. The locally variable pressure is seen to be highly sensitive to the flow index ＂n＂. The study clearly shows that continuous fluid transport for Newtonian/rheological fluids by wave train propagation is more effective than widely spaced single wave propagation in the case of peristaltic movement of food bolus in the esophagus.
文摘Objective:To investigate the possible mechanisms of the decreasing fluid and food consumption following Hibiscus sabdariffa(HS) consumption.Methods:On the 1st day of pregnancy,rats were randomly divided into three groups with six animals per each group.One group was given tap water,one was given with extract at 0.6 g/100 mL while the third group was given with extract at 1.8 g/100 mL as their drinking solution.All groups received normal rat chow and drinking solution ad libitum.Fluid& food intake and weight were measured daily throughout pregnancy and Na^+ concentration in plasma was determined on the 18th day of pregnancy.Results:Results showed decreased fluid and food consumption,decreased weight gain and increased sodium ion concentration in plasma of rats with HS extract compared with the control group.Conclusions: Consumption of aqueous extract of the calyx of HS during pregnancy decreases food consumption and weight gain through mechanisms that may depend on Na^+ in HS content and elevating Na^+ concentration.
