Cryogenic MMIC low noise amplifiers

Monolithic (MMIC) and discrete transistor (MIC) low noise amplifiers are compared on the basis of performance, cost, and reliability. The need for cryogenic LNA’s for future large microwave arrays for radio astronomy is briefly discussed and data is presented on a prototype LNA for the 1 to 10 GHz range along with a very wideband LNA for the 1 to 60 GHz range. A table of MMIC LNA and mixer designs under development for the frequencies up to 210 GHz is reported and data on cryogenic amplifiers in the 85 to 115 GHz is reviewed. The current status of the topics of transconductance fluctuations and cryogenic noise modeling will be briefly summarized

Advanced surface paneling method for subsonic and supersonic flow

Numerical results illustrating the capabilities of an advanced aerodynamic surface paneling method are presented. The method is applicable to both subsonic and supersonic flow, as represented by linearized potential flow theory. The method is based on linearly varying sources and quadratically varying doublets which are distributed over flat or curved panels. These panels are applied to the true surface geometry of arbitrarily shaped three dimensional aerodynamic configurations

Wilson loops in SYM theory: from weak to strong coupling

We review Wilson loops in N=4 supersymmetric Yang-Mills theory with emphasis on the exact results. The implications are discussed in the context of the AdS/CFT correspondence.Comment: 32 pages, 5 figure

Factory Automation: A Controls Course for Every University

The majority of new control engineering positions is now in manufacturing and involves programmable logic controllers (PLCs). The paper describes two courses developed at the University of Missouri-Rolla to satisfy this demand. Both courses present the subject of programming PLCs with an emphasis on the design of the programs. Both courses contain an integral laboratory component that solidifies the concepts presented in the lectures. The philosophy and pedagogical features of the two courses are first described, followed by the structure of the lecture and the laboratory exercises