Potential New Applications of SQUIDS and SQUID Arrays in NDE

There are a number of applications in NDE in which SQUID based instrumentation can potentially provide substantial improvements over room temperature electronics. In addition to direct measurements of the magnetic signatures of cracks and flaws, experiments have shown that SQUIDs may be used as ultrasensitive detectors of AC fields for eddy current detection, detection of magnetic fields due to electrochemical corrosion currents, and detection of NMR signals. Recent results in all these areas will be summarized together with the relative advantage of using SQUID based systems

Work-related respiratory illnesses as perceived by the working population in Hong Kong

Most papers are about method and results, building blocks in the temples of physics and engineering. And rightly so. But this paper is about process, the process of discovery and of creativity. It is about frustration, joy, commitment, determination, steadfastness, failure, and ultimately triumph. It is about people, about John Moulder, poet and physicist. It is about our work to marry pulsed eddy currents with SQUIDS1, during an intense few days in February 1996

Modulation instabilities in a system of four coupled, nonlinear Schrödinger equations

The modulation instability of continuous waves for a system of four coupled nonlinear Schrödinger equations, two of which are in the unstable regime, is studied. In earlier studies, plane or continuous waves for a system of two coupled, nonlinear Schrödinger equations is shown to exhibit modulation instability (MI), even if both modes are in the normal dispersion regime, provided that the coefficient of cross phase modulation (XPM) is larger than that of self phase modulation (SPM). Requirements for MI in this system of four coupled, nonlinear Schrödinger equations can be relaxed. MI can occur even if the magnitude of XPM is less than that of SPM, and the magnitude of instability is generally larger than that of each mode alone. The implications for parametric process and wavelength exchange in optical physics with two pump waves are discussed. © 2008 Elsevier B.V. All rights reserved.link_to_subscribed_fulltex