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Weigh-in-motion (WIM) systems differ in terms of sensing technology, sensing element, installation procedure, structural design, and material, which make them respond differently to equivalent loading conditions. The research objective was to investigate the performance of three types of piezoelectric WIM sensors in a medium strength asphalt concrete pavement of stone mastic design under different vehicle speeds and cold and warm air temperature factors using the factorial experiment method. A multiple-sensor WIM system was installed at the test site and included different types of sensors such as quartz, polymer, and ceramic piezoelectric sensors. The quartz sensors showed insensitivity to speeds higher than 30 km/h and air temperature; whereas, the effects of air temperature and speed on the ceramic sensors were significant. The polymer sensors demonstrated sensitivity to the speed (on auto-calibrated sensors specifically for lower than 30 km/h) and air temperature factors. Acquired knowledge about the effects of major climate and traffic factors on performance of the least expensive piezoelectric sensors will assist in developing an effective auto-compensation algorithm specifically for improving estimation of polarized piezoelectric sensors. [ABSTRACT FROM AUTHOR]

This paper reports the results of characterization and optimization experiments carried out on a newly developed NX-3 dense plasma focus device (20 kJ at 20 kV, a quarter time period of \sim\!\!3\ \mu\s, and 10 kJ/600 kA at 14 kV) at the Plasma Radiation Source Laboratory, NIE, Nanyang Technological University, Singapore. Initial experiments were conducted with an electrode assembly configuration having anode radius and length of 20 and 160 mm, respectively, for detailed neutron emission characterization of NX-3 device followed by further optimization of neutron yield using various other electrode configurations designed using the Lee Code. At \geq10-kJ operation, the average neutron yield on the order of 10^9 neutrons/pulse in 4\pi\sr was obtained for the deuterium filling gas pressure range of 6–8 mbar. The neutron yield of \sim\!\!4.6 \times 10^9 neutrons/pulse at 10 kJ/6 mbar is the highest ever reported for a device with the same stored energy. The neutron anisotropy measurements point to the beam–target mechanism as the dominant neutron production mechanism for NX-3 plasma focus device. Further optimization of neutron yield in NX-3 was achieved with the peak average neutron yield being enhanced from \sim\!\!(2.38 \pm 0.31) \times 10^9 neutrons/shot for the initial electrode configuration to about \sim\!\!(3.40 \pm 0.43) \times 10^9 neutrons/shot for the electrode configuration with anode radius and length of 26 and 140 mm, respectively. The analysis of neutron yield results for various electrode assembly configurations demonstrates the speed factor as a key optimization tool for maximization of neutron yield. [ABSTRACT FROM PUBLISHER]