10K Pulse Tube Cooler
A 3-stage pulse tube cooler has been designed to operate at 10¶K. The staged cooler uses the same compressor and parallel staging configuration for the 1 st and 2 nd stages as previously employed for our delivered High Capacity Cryocooler (HCC). The 2 nd and 3 rd stages are in a serial configuration. The addition of the third stage extends the performance of this cooler to lower operating temperatures below 10¶K.
High Capacity Staged Pulse Tube
The High Capacity Cryocooler (HCC) is being designed to provide large capacity cooling at 35 K and 85 K for space applications in which both cold focal planes and optics require cooling. The compressor is scaled from the High Efficiency Cryocooler compressor and is capable of using input powers up to 700 W. The two linear pulse tube cold heads are integrated with the compressor into an integral cryocooler. Provision is made to provide a thermal strap between the cold heads in order to improve efficiency. The cooler is undergoing acceptance testing that includes thermal performance mapping over a range of reject temperatures and power levels, launch vibration testing and self induced vibration testing.
Gut immunity in Lepidopteran insects.
Lepidopteran insects constitute one of the largest fractions of animals on earth, but are considered pests in their relationship with man. Key to the success of this order of insects is its ability to digest food and absorb nutrition, which takes place in the midgut. Because environmental microorganisms can easily enter Lepidopteran guts during feeding, the innate immune response guards against pathogenic bacteria, virus and microsporidia that can be devoured with food. Gut immune responses are complicated by both resident gut microbiota and the surrounding peritrophic membrane and are distinct from immune responses in the body cavity, which depend on the function of the fat body and hemocytes. Due to their relevance to agricultural production, studies of Lepidopteran insect midgut and immunity are receiving more attention, and here we summarize gut structures and functions, and discuss how these confer immunity against different microorganisms. It is expected that increased knowledge of Lepidopteran gut immunity may be utilized for pest biological control in the future.