A low noise 410-495 heterodyne two tuner mixer, using submicron Nb/Al2O3/Nb tunneljunctions

A 410-495 GHz heterodyne receiver, with an array of two Nb/Al2O3/Nb tunneljunctions as mixing element is described. The noise temperature of this receiver is below 230 K (DSB) over the whole frequency range, and has lowest values of 160 K in the 435-460 GHz range. The calculated DSB mixergain over the whole frequency range varies from -11.9 plus or minus 0.6 dB to -12.6 plus or minus 0.6 dB and the mixer noise is 90 plus or minus 30 K

Hygroscapes: Innovative Shape Shifting Façades

This chapter focuses on the testing and design of shape shifting façade prototypes that are programmed to passively sense stimuli and respond in a controlled setting based on the hygroscopic properties of wood. Wood is introduced in this context as a low-tech smart material with a naturally soft responsive mechanism that offers a substitute for mechanical actuators. First, a set of physical experiments were conducted to deduce the design parameters that affect wood morphology, behavior and response time upon changes in humidity levels and moisture content, including dimensional ratio, grain orientation, material thickness, type of wood, and lamination. We then report on the process and outcome of a workshop held at the American University in Cairo, with the main challenge of regulating the morphology and hygroscopic behavior of wood to work as an actuator with specifically desired motion for adaptive building façade prototypes. Based on the observations and analysis of concepts and mechanisms, we discuss shape shifting grammars as a framework for devising adaptive façade prototypes from a generative design perspective, where specific combinations of motion parameters are used to induce semantic rules and customized commands for the overall behavior of shape shifting mechanisms