Broadband TDMA over the indoor radio channel

Prior work has focused on the negative aspects of time-dispersive channels and associated intersymbol interference. The authors show that the inherent diversity introduced by such dispersion is advantageous in reducing the performance-limiting effects of flat fading. This is demonstrated for an indoor QPSK radio link employing a decision-feedback equaliser     

Eucalyptol is an Attractant of the Redbay Ambrosia Beetle,Xyleborus Glabratus

The redbay ambrosia beetle, Xyleborus glabratus, is an invasive wood-boring beetle that has become established in the southeastern United States. The beetle transmits the causal pathogen of lethal laurel wilt to susceptible host trees, which include redbay, an important forest community species, and avocado, a valuable food crop. By examining odors of redbay wood, we developed an artificial lure that captured X. glabratus in redbay forests. Eucalyptol was a critical component of the blend for beetle attraction, and eucalyptol alone in large quantities attracted X. glabratus. Furthermore, eucalyptol stimulated boring by X. glabratus into paper arenas. The results suggest that eucalyptol contributes to host selection behavior of X. glabratus and may be useful for management of this pathogen vector.     

The control of biofilms in tubes using wire‐wound inserts

As a possible alternative to the use of biocides in industrial water systems, studies have been made on the effectiveness of wire‐wound tube inserts for biofilm control. Comparisons of data obtained at two different empty tube velocities of 0.86 m/s and 1.27 m/s and a Reynolds number of 14 000 with and without inserts, show that a biofilm accumulation reduction approaching 50% can be achieved by the use of inserts under certain circumstances. Further work is required to establish the optimum design of insert for maximum effectiveness.     

Ultrapure materials for alpha particle-sensitive applications

Materials used in applications where alpha particle radiation can produce “soft” or transitory errors are commonly specified and characterized in terms of uranium and thorium content, often by glow discharge mass spectrographic analysis. Analytical results indicate that low levels of uranium and thorium do not adequately reflect the alpha flux potential of some materials, especially in cases where radioactive isotopes are not in equilibrium or where a dominant decay parent other than uranium or thorium is present. An additional characterization technique—highly sensitive, surface alpha particle flux measurement—has been developed. Alpha particle counting, when used in conjunction with trace metal analysis, allows more optimum selection of low-alpha-radiation materials.     

Kinetics of thermal synthesis of cerium sulfides

One of the most promising applications for cerium sulfide is as a refractory for molten metal processing, particularly for reactive actinides. Separate processes were used to synthesize cerium monosulfide, cerium sesquisulfide (Ce₂S₃) and cerium hydride (CeH₂). High purity Ce₂S₃ was produced by reacting ceria (CeO₂) and hydrogen sulfide (H₂S) in an induction furnace using a carbon catalyst at temperatures above 2000 °C. CeH₂ was synthesized from cerium metal and hydrogen gas at 100 °C. Ce₂S₃ and CeH₂ were subsequently reacted together in an induction furnace at temperatures above 1700 °C to produce CeS. X-ray diffraction was used to analyze synthesized samples and the kinetics of the CeS synthesis reaction was modeled using a diffusion-limited reaction model. The activation energy for the process was estimated to be 190 kJ/mol.     

Recent applications of linear analysis techniques

This paper is based on material presented at the Panel Session: Recent Applications of Linear Analysis Techniques conducted during the 1998 IEEE PES Summer Meeting. The topics discussed include: control system design; system identification; large scale system applications; simultaneous coordination of power system stabilisers and FACTS controllers; robust power system stabilisation; small signal stability analysis based on time-domain identified models; EM transient studies modal analysis; and power system dynamics nonlinearities, normal forms method     

Hybrid serial-parallel digital computation

The design of a fully parallel-digital computer broadly equivalent to an analogue computer is outlined. Comparable performance with an analogue is shown from solutions to an optimal control problem involving linear programming. Parallel operation with a serial digital computer carrying out dynamic programming, demonstrates the performance feasibility of the parallel digital replacing the analogue computer and providing an all digital hybrid serial-parallel computing facility or on-line computer controller.