Heat pipe cooling of power processing magnetics

A heat pipe cooled transformer and input filter were developed for the 2.4 kW beam supply of a 30 cm ion thruster system. This development yielded a mass reduction of 40% (1.76 kg) and lower mean winding temperature (20 C lower). While these improvements are significant, preliminary designs predict even greater benefits to be realized at higher power. The design details are presented along with the results of thermal vacuum operation and the component performance in a 3 kW breadboard power processor

The Microbial Flora of Acid Mine Water and its Relationship to Formation and Removal of Acid

(print) viii, 124 p. illus. 28 cm.Title Page -- Table of Contents -- List of Tables -- List of Figures -- I: Introduction -- II: The Influence of Acid Water on Aerobic Heterotrophs of A Normal Stream -- III: The Relative Influence of Iron, Sulfate and Hydrogen Ions on the Microflora of A Non-Acid Stream -- IV: Aerobic Heterotrophs Indigenous to pH 2.8 Mine Water -- V: A Microbial Dissimilatory Sulfur Cycle -- VI: Microbial Sulfate Reduction in Acidic Mine Water and Its Potential Utility as A Water Pollution -- VII: General Summary and Conclusions -- VIII: Recommendations -- IX: Publications Resulting from this Research Projec

The living aortic valve: From molecules to function.

The aortic valve lies in a unique hemodynamic environment, one characterized by a range of stresses (shear stress, bending forces, loading forces and strain) that vary in intensity and direction throughout the cardiac cycle. Yet, despite its changing environment, the aortic valve opens and closes over 100,000 times a day and, in the majority of human beings, will function normally over a lifespan of 70-90 years. Until relatively recently heart valves were considered passive structures that play no active role in the functioning of a valve, or in the maintenance of its integrity and durability. However, through clinical experience and basic research the aortic valve can now be characterized as a living, dynamic organ with the capacity to adapt to its complex mechanical and biomechanical environment through active and passive communication between its constituent parts. The clinical relevance of a living valve substitute in patients requiring aortic valve replacement has been confirmed. This highlights the importance of using tissue engineering to develop heart valve substitutes containing living cells which have the ability to assume the complex functioning of the native valve

The Ecologic Impact of the Interactions Among Microorganisms and Aquatic Contaminants in Lake Erie Phase III Parts 5, 6, and 7

This study was supported in part by the Office of Water Resources Research. U.S. Department of the Interior, under Project B-025-OHIO(print) 172 p.Part 5: List of Figures -- List of Tables -- Introduction -- Literature Review -- Materials and Methods -- Results -- Discussion -- Summary -- BibliographyPart 6: List of Figures -- List of Tables -- Introduction -- Review of Literature -- Materials and Methods -- Results -- Discussion -- Appendix A -- Appendix B -- BibliographyPart 7: List of Illustrations -- List of Tables -- Introduction -- Review of Literature -- Materials and Methods -- Results -- Discussion -- Summary -- Literature Cite

Flexible Architecture for FPGAs in Embedded Systems

Commonly, field-programmable gate arrays (FPGAs) being developed in cPCI embedded systems include the bus interface in the FPGA. This complicates the development because the interface is complicated and requires a lot of development time and FPGA resources. In addition, flight qualification requires a substantial amount of time be devoted to just this interface. Another complication of putting the cPCI interface into the FPGA being developed is that configuration information loaded into the device by the cPCI microprocessor is lost when a new bit file is loaded, requiring cumbersome operations to return the system to an operational state. Finally, SRAM-based FPGAs are typically programmed via specialized cables and software, with programming files being loaded either directly into the FPGA, or into PROM devices. This can be cumbersome when doing FPGA development in an embedded environment, and does not have an easy path to flight. Currently, FPGAs used in space applications are usually programmed via multiple space-qualified PROM devices that are physically large and require extra circuitry (typically including a separate one-time programmable FPGA) to enable them to be used for this application. This technology adds a cPCI interface device with a simple, flexible, high-performance backend interface supporting multiple backend FPGAs. It includes a mechanism for programming the FPGAs directly via the microprocessor in the embedded system, eliminating specialized hardware, software, and PROM devices and their associated circuitry. It has a direct path to flight, and no extra hardware and minimal software are required to support reprogramming in flight. The device added is currently a small FPGA, but an advantage of this technology is that the design of the device does not change, regardless of the application in which it is being used. This means that it needs to be qualified for flight only once, and is suitable for one-time programmable devices or an application specific integrated circuit (ASIC). An application programming interface (API) further reduces the development time needed to use the interface device in a system