Search

An Engineering Model (EM) of a Miniature Pulse Tube Cooler (MPTC) has been designed, manufactured and tested in partnership between AL/DTA, CEA/SBT and THALES Cryogenics. Prior to the EM manufacturing, a development phase was performed with an in-line architecture for the cold finger and using an existing flexure bearing compressor from THALES Cryogenics. The optimized development model pulse tube cooler demonstrated a cooling capacity of 1 W at 82 K with 25 watts PV work and 288 K heat rejection temperature. Based on this experience, the EM cooler reported on here has been designed and manufactured with a U-shaped architecture to provide a more compact cooler for improved integration. In this paper, thermal and mechanical test results for the new EM cooler are presented and analyzed for various heat sinking temperatures, input powers, and orientations. [ABSTRACT FROM AUTHOR]

Thales Cryogenics has been working on high reliability cryocoolers since 1997. During this period two cooler series have been developed, the LSF91xx series for cooling powers up to 3 W at 80 K and the LSF93xx series for cooling powers up to 8 W at 80 K. As a result of several design improvements, it was possible to decrease the length and mass of our flexure-bearing coolers. These improvements have been applied in the new LSF95xx series. With the length and mass reduction, the LSF95xx complies with the SADA II specification with respect to envelope and mass. Based on this, being the first manufacturer offering a full flexure-bearing supported cooler that fits within the SADA II envelope, Thales Cryogenics has been selected in several new (military) programs with their LSF coolers. By using a moving magnet configuration in all our flexure-bearing coolers, the risk with respect to contamination problems due to outgassing has been diminished because the coils are not part of the helium circuit. Furthermore, all connections in the LSF95xx are laser-welded, which means that there is no additional locking required inside the cooler. By using a different magnet design, no magnet segments have to be glued together, which decreases the risk of out gassing and increases the robustness even more. This paper describes the trade-offs that have been considered in the design phase, and gives a detailed overview of the test results, the status of the qualification program, and the resulting specification of the LSF95xx cooler series. [ABSTRACT FROM AUTHOR]

Chapter 20 of the book "Knowledge Management Tools & Techniques" is presented. It situates the role of information technology (IT)-enabled creativity tools within overall idea generation mechanisms in organizations. According to it, creativity is a key knowledge connector and has been managed successfully in firms such as Unilever as part of a formalized innovation process with a strict discipline and selection methodology.

The scientific community has an important role to play in public policymaking. However, several difficulties impede productive incorporation of science into decisionmaking. One difficulty is that most scientists lack essential knowledge and experience of decision and policymaking processes at all governmental levels, and therefore do not know how to participate effectively in these processes. If a scientist wants to be more effective, he or she has to take political discourse seriously. A second aspect is that a holistic scientific viewpoint is necessary to improve decisionmaking. Methods to understand behavior at the whole-system level - both natural and human dimensions - are required to replace the reductionistic approaches that attempt to solve problems piecemeal. The global extent of environmental problems is a clear signal that piecemeal problem solving does not result in effective decisionmaking. The challenge rests in developing a transparent process in which scientists and policymakers share information equally about scientific needs, political realities, and economic choices. [ABSTRACT FROM AUTHOR]