SiC power device design and fabrication, and insertion in novel MV power converters
• The U.S Department of Energy launched the PowerAmerica Institute under the initiative of “National Network of Manufacturing Institutes (NNMI)” to Accelerate Adoption Wide Band Gap (WBG) power devices • PowerAmerica started operations in 2015 with $140M funds over 5 years, and is managed by North Carolina State University in Raleigh, NC USA • PowerAmerica addresses gaps in technology to enable manufacturing that contributes to its mission of realizing manufacturing jobs creation and energy savings through accelerated large-scale adoption of WBG semiconductor devices in power electronic systems.
Characterization of IGCTs for series connected operation
This paper describes the series connection of integrated gate commutated thyristors (IGCTs) using RC-snubbers. An experimental setup with a power rating of 6 kV, 4 kA is used to analyze the dynamic and static behavior of the series connected IGCTs in detail. The mechanism of thermal stabilization of series connected IGCTs is discussed. It is shown that a good voltage balancing can be achieved by small RC-snubbers due to the fast switching IGCTs.
Design and Development of an In Vitro Tear Replenishment System
Understanding the cellular and molecular mechanisms of the corneal tissue and translating them into effective therapies requires organotypic culture systems that can better model the physiological conditions of the front of the eye. Human corneal in vitro models currently exist, however, the lack of tear replenishment limits corneal in vitro models’ ability to accurately simulate the physiological environment of the human cornea. The tear replenishment system (TRS), a micro-fluidic device, was developed to mimic the in vivo tear replenishment in the human eye in an in vitro corneal model. The TRS is capable of generating adjustable intermittent flow from 0.1 µL in every cycle. The TRS is a sterilizable device that is designed to fit standard 6-well cell culture plates. Experiments with the corneal models demonstrated that exposure to the TRS did not damage the integrity of the stratified cell culture. Contact lenses “worn” by the in vitro corneal model also remained moist at all times and the cytotoxicity of BAK could also be verified using this model. These in vitro results confirmed that the TRS presents novel avenues to assess lens-solution biocompatibility and drug delivery systems in a physiologically relevant milieu.