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Several plant growth systems have been tested for crop production in microgravity and lunar/Mars environments in support of NASA's Advanced Life Support Program and long-term human space missions. These systems have incorporated such design features as the nutrient film technique (NFT), microporous plates, microporous tubes, and expandable boundary chambers and have been developed and used to support sweetpotato production at Tuskegee University. In the present research, the performance of different sweetpotato cultivars in a microporous tube system with lunar simulant medium was studied. The lunar simulant is an inert aggregate with an average particle size of about 3 mm. Buried in this solid medium is a microporous tube. Nutrient solution is circulated through the microporous tube under a slight negative pressure. This pressure is controlled to allow a slight seepage from the tube with some accumulation of water in the solid medium, but no free water.

Chrysler Corporation has developed an 8.0-liter engine for light truck applications. Numerous features combine to produce the highest power and torque ratings of any gasoline-fueled light truck engine currently available while also providing commensurate durability. These features include: a deep-skirt ten-cylinder 90° “V” block, a Helmholtz resonator intake manifold that enhances both low and mid-range torque, light die cast all-aluminum pistons for low vibration, a unique firing order for smooth operation, a “Y” block configuration for strength and durability, a heavy duty truck-type thermostat to control warm up, and a direct ignition system.

This paper presents an integrated design/simulation/test approach for evaluating the sound quality of exhaust noise as early as possible in the exhaust system design and development process. A time domain engine/exhaust simulation program is used to calculate the engine order content of the tailpipe radiated noise from an odd fire V-10 exhaust system. Both steady state and transient conditions are simulated and sound files generated for exhaust sound quality evaluation. To increase the realism of played back sounds, the predicted engine orders are mixed with synthesized or recorded background noise for both steady state and transient conditions. These alternative approaches will be described and evaluated for technical feasibility and sound quality.