Abstract: A method of determining if a radiation spectra comprises radiation corresponding to naturally occurring radiation material sources (NORM), the method including: gathering the radiation spectra; normalizing the gathered spectra by using one or more predefined normalization techniques; energy scaling the normalized spectra by using one or more energy scaling techniques; and determining materials corresponding to each energy reading in the scaled energy spectra for categorizing the determined materials into one or more predefined categories by using one or more classification algorithms.

Abstract: Various examples of systems for powering a linear motor with a multi-phase amplifier are described herein. In some embodiments, an apparatus includes a plurality of current sources for supplying power to an electronic device. The plurality of current sources are configured to supply a substantially constant direct current to a load, and each of the plurality of current sources is configured to supply a periodic alternating current that is out of phase relative to the periodic alternating current of one or more of the other current sources. A sum of the periodic alternating currents from the plurality of current sources is configured to provide the substantially constant direct current. Embodiments of the systems can be used in vibration testing equipment such as electro-dynamic shakers.

Abstract: A solid state amplifier for driving a shaker is described. The amplifier is comprised of a circuit which generates a pulse-width modulated drive signal for driving an armature of a shaker. The circuit includes an oscillator, power supply, wave-shaping generator, error detection network, comparator modulator and drive amplifiers. The oscillator generates a base waveform which is shaped by the wave-shaping generator. This signal is compared with error signals and the resulting signal is used to provide the pulse-width modulated driving signal to the shaker.