Axially symmetrical Fabry-Perot oscillator with multiple devices inserted in dielectric substrate

We investigate an axially symmetrical Fabry-Perot oscillator with active devices inserted in a dielectric substrate for power combining of many more devices in the microwave and millimeter wave frequency range. Empirically in this oscillator, efficient power combining can be done when it oscillates approximately at the frequency which corresponds to the wavelength equal to twice the spacing between the devices. The wavelength in the dielectric is shorter than in free space, so we tried to insert the devices in the dielectric substrate in order to increase the number of devices. By measuring the oscillation frequency of the oscillator with sixteen devices at X-band, we confirmed that the spacing between devices was about a half wavelength in the dielectric. We achieved almost perfect power combining of sixteen device

Resident willingness to pay for local, ecologically sustainable and cultural food production and consumption in Hawaii

This study is part of a larger objective to produce data to develop an appropriate marketing campaign for ecologically sustainable and cultural food production for consumption through data analysis on key audience, industry leaders, and Hawaii\u27s food production. This paper covers a smaller (n=100) study as a mode for survey of locals willingness to pay for ecologically sustainable and cultural food production and consumption . Through our findings we establish a statistically significant willingness to pay more for consumption of food grown through ecologically sustainable and cultural food production in Hawaii

An Evaluation of Turbocharging and Supercharging Options for High-Efficiency Fuel Cell Electric Vehicles

Mass-produced, off-the-shelf automotive air compressors cannot be directly used for boosting a fuel cell vehicle (FCV) application in the same way that they are used in internal combustion engines, since the requirements are different. These include a high pressure ratio, a low mass flow rate, a high efficiency requirement, and a compact size. From the established fuel cell types, the most promising for application in passenger cars or light commercial vehicle applications is the proton exchange membrane fuel cell (PEMFC), operating at around 80 °C. In this case, an electric-assisted turbocharger (E-turbocharger) and electric supercharger (single or two-stage) are more suitable than screw and scroll compressors. In order to determine which type of these boosting options is the most suitable for FCV application and assess their individual merits, a co-simulation of FCV powertrains between GT-SUITE and MATLAB/SIMULINK is realised to compare vehicle performance on the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) driving cycle. The results showed that the vehicle equipped with an E-turbocharger had higher performance than the vehicle equipped with a two-stage compressor in the aspects of electric system efficiency (+1.6%) and driving range (+3.7%); however, for the same maximal output power, the vehicle’s stack was 12.5% heavier and larger. Then, due to the existence of the turbine, the E-turbocharger led to higher performance than the single-stage compressor for the same stack size. The solid oxide fuel cell is also promising for transportation application, especially for a use as range extender. The results show that a 24-kWh electric vehicle can increase its driving range by 252% due to a 5 kW solid oxide fuel cell (SOFC) stack and a gas turbine recovery system. The WLTP driving range depends on the charge cycle, but with a pure hydrogen tank of 6.2 kg, the vehicle can reach more than 600 km