Development, Analysis, and Comparison of Electromechanical Properties and Electrode Morphology of Ionic Polymer Metal Composites

With smart materials and adaptive structures being nudged into mainstream technology progressively, the smart composites are donning a predominant role as indispensable structures. Among these, the Ionic Polymer Metal Composites (IPMC), with their large bending deformation and relaxation characteristics at very low voltages are attractive as transducers in many areas of application. The actuation and sensing properties of IPMC have been sought after for various engineering functions. The paper focuses on manufacturing various types of IPMC. Combining the ionic polymer with platinum electrodes, gold sputter coated electrodes and multi-walled carbon nanotube Bucky paper electrodes to create enhanced IPMCs, comparative analysis of different manufacturing methodologies discussing the electrode morphology using scanning electron microscopy and energy dispersive X-ray spectroscopy techniques is studied. A comparison of the uniformity of the electrode plating obtained from the different processes is studied while the research also concentrates on making use of different ionic solutions to change the anions within the polymer membrane for comparison such as to determine the most suited ion content within the solid electrolyte for effective IPMC actuation. A COMSOL multiphysics model is attempted in this thesis, which effectively describes a multiphysics modeling approach for the IPMC. This new functionally graded material is tested for its bending deformation, blocking force and the current consumption to prove the electro-mechanical efficiency of the platinum, gold and Bucky paper IPMC. By studying the electromechanical properties of this smart composite actuator based on its actuation under different electric excitations, we can draw conclusions subsequently from the results of the comparison

Hybrid Magneto-Active Propellant Management Device for Active Slosh Damping Within a Vehicle Fuel Tank

This disclosure includes a hybrid magneto-active mem­brane, which can be used as part of a Magneto-active Propellant Management Device (MAPMD), to actively con­trol free surface effects of liquid materials, such as fuels, and to reduce fuel slosh. The disclosed MAPMD merges aspects of a diaphragm membrane with a magneto-active inlay to control the membrane during in-flight conditions

Hybrid Magneto-Active Propellant Management Device for Active Slosh Damping Within a Vehicle Fuel Tank

This disclosure includes a hybrid magneto-active mem­brane, which can be used as part of a Magneto-active Propellant Management Device (MAPMD), to actively con­trol free surface effects of liquid materials, such as fuels, and to reduce fuel slosh. The disclosed MAPMD merges aspects of a diaphragm membrane with a magneto-active inlay to control the membrane during in-flight conditions

Hybrid Magneto-Active Propellant Management Device for Active Slosh Damping in Spacecraft

This disclosure includes a hybrid magneto-active membrane, which can be used as part of a Magneto-active Propellant Management Device (MAPMD), to actively control free sur­face effects of liquid materials, such as fuels, and to reduce fuel slosh. The disclosed MAPMD merges aspects of a dia­phragm membrane with a magneto-active inlay to control the membrane during in-flight conditions

An Investigation of the Magneto-Active Slosh Control for Cylindrical Propellant Tanks Using Floating Membranes

The phenomenon of sloshing is a substantial challenge in propellant management, particularly in reduced gravity where surface tension-driven flows result in large slosh amplitudes and relatively long decay time scales. Propellant Management Devices (PMDs) such as the rigid baffles and elastomeric membranes are often employed to counteract motion of the free surface. In the present study, we investigate an active PMD that utilizes a free-floating membrane that, under an applied static magnetic field, becomes rigid and suppresses slosh. This semi-rigid structural layer can thereby replace bulky baffle structures and reduce the overall weight of the tank. In this paper, the membrane was fabricated using Metglas 2714A alloy in a weave pattern and the experiment was run for varying slosh amplitudes at a given magnetic field gradient using the slosh research facility at Embry Riddle Aeronautical University. The resultant force acting on the walls of the cylinder is recorded for each test run using a pair of load cells that are attached at the end of each movable arm. Computational Fluid Dynamics (CFD) simulations were setup with the parameters of the experiment to verify and validate the experimental setup. The result of this investigation provides information on the magnetic field gradient required to control certain amplitude of slosh or in other words, the maximum amplitude of slosh that can be controlled for a given magnetic field

Floating Active Baffles, System and Method of Slosh Damping Comprising the Same

This disclosure provides a system for damping slosh of a liquid within a tank, a baffle for use in the system, and a method of damping slosh using the system. The system includes a plurality of baffles. Each baffle has a body configured to substantially float upon the liquid. Each baffle also has an activation material received along at least a portion of the body. The activation material is magnetically reactive provided in a quantity sufficient to enable the body to be manipulated in the presence of a magnetic field (M). The system further includes an actuator configured to pro­vide the magnetic field (M)

Utility of pulse-oximetry screening in newborns with nonductus-dependent cyanotic congenital heart defects: A reason to alarm?

Objectives : We aimed to compare the performance of pulse-oximetry screening in detecting nonductus-dependent cyanotic congenital heart defects (CCHDs). Methods : In a prospective cross-sectional study, we recorded post ductal saturation of neonates (<48 h old) born at a community hospital in northern India. Subsequently, all underwent clinical examination and echocardiogram by a trained cardiologist. A saturation <95% was considered a “failed” screen. Results : Ten neonates were identified to have nonductus-dependent CCHD on echocardiogram, five of whom had passed pulse-oximetry screen. This translated to a sensitivity of 50% (95% confidence interval [CI] 23.7%–76.3%) and a positive predictive value of 0.08 (95% CI 0.03–0.2), both of which were significantly less compared to that in ductus-dependent congenital heart defect. Conclusions : Up to half of the nonductus-dependent CCHD may be missed if screened only using pulse oximetry. Parents should not be reassured regarding the absence of CCHD only based on a “pass” in pulse-oximetry screening