Fabrications of nanofibers as crossed arrays by electrospinning.

We have developed a new method for obtaining nanofiber crossed arrays by exploiting an auxiliary electrode subjected to electrical frequencies, between the capillary tip and the grounded target in an electrospinning machine. The frequencies generated crossed arrays on a flat collector, used instead of a rotating wheel because of intersecting jets. We observed many straight and crossed structures.

Hysteresis in a carbon nanotube based electroactive polymer microfiber actuator: numerical modeling.

Hysteretic behavior is an important consideration for smart electroactive polymer actuators in a wide variety of nano/micro-scale applications. We prepared an electroactive polymer actuator in the form of a microfiber, based on single-wall carbon nanotubes and polyaniline, and investigated the hysteretic characteristics of the actuator under electrical potential switching in a basic electrolyte solution. For actuation experiments, we measured the variation of the length of the carbon-nanotube-based electroactive polymer actuator, using an Aurora Scientific Inc.

Airflow velocities in the airways during expiration on different end-expiratory lung volumes: computational study.

We used our computational model of the respiratory system which features non-linear variation of airway dimensions and airway-generation-based structure to show airflow velocities (cm/sec) during natural slow expiration on different end-expiratory lung volumes. Expiratory airflow rates at the mouth can be easily measured using a flow meter. However, because there is no practical non-invasive method that is currently available to measure airflow velocity in the airways, the airflow velocities in airway generations 0 approximately 16 were studied using the computational model.

Modeled velocity of airflow in the airways during various respiratory patterns.

Our modeling and simulation of the respiratory system with Weibel's morphometry shows that the average velocity of expiratory airflow is always greater than the average velocity of inspiratory airflow during tidal breathing when the intervals of inspiration and expiration are same. A nonlinear circuit model was developed comprised with the upper airway, the conducting airways (trachea approximately terminal bronchioles), and the lumped alveolar space. These compartments are established with known physiologic pulmonary characteristics that are represented by nonlinear resistors and capacitors.

Investigation of non-uniform airflow signal oscillation during high frequency chest compression.

Background: High frequency chest compression (HFCC) is a useful and popular therapy for clearing bronchial airways of excessive or thicker mucus. Our observation of respiratory airflow of a subject during use of HFCC showed the airflow oscillation by HFCC was strongly influenced by the nonlinearity of the respiratory system. We used a computational model-based approach to analyse the respiratory airflow during use of HFCC.