The control of sprayer boom undesired vibrations pose a great challenge to investigators due to various disturbances and conditions. Sprayer boom movements lead to reduce of spread efficiency and crop yield. This paper describes the design of a novel control method for an active suspension system applying proportional-integral-derivative (PID) controller with an active force control (AFC) schem...

Sonic boom research conducted at NASA through the Supersonics Project of the Fundamental Aeronautics Program is oriented toward understanding the potential impact of sonic boom noise on communities from new low-boom supersonic aircraft designs. Encompassing research in atmospheric propagation, structural response, and human response, NASA research contributes to knowledge in key areas needed to...

Generally, both horizontal and vertical boom motion must be used to suppress the load sway caused by horizontal boom motion of a rotary crane. However, it would be less energy intensive and also safer if a control scheme could be developed that only used horizontal boom motion, i.e., without the need for any vertical boom motion. In addition, if load sway can be suppressed without measuring it,...

There are several research papers on how to design a supersonic configuration that has desirable low-boom characteristics as determined by the Seebass-George-Darden boom minimization theory (SGD theory). The low-boom signatures predicted by the SGD theory could be realized by wing-fuselage configurations. However, for a given low-boom signature generated by the SGD theory, it is still an open q...

The application of pre-emergence, post-emergence, and burn-down herbicides (i.e., glyphosate) continues to increase as producers attempt to reduce both negative environmental impacts from tillage and input costs from labor, machinery and materials. The use of precision agriculture technologies such as automatic boom section control allows producers to reduce offtarget application when applying ...

Since the ratio of gold to oil and silver has an important impact on financial market, its periodic changes will affect trading gold, so mode strategy as futures must be analyzed judged conclusion, use correct for trading. In order obtain most accurate way trading, knowledge time series was used in statistics analyze from perspective historical data, cyclical data ratio, finally summarize a set...

We show that the oil market has become closer to 'one great pool,' in sense price differentials between crude oils of different qualities have generally smaller over time. document, particular, many these experienced a major structural break or around 2008, after which there was marked reduction their means and volatilities. Differentials residual fuel oil, low-quality fuel, higher-valued produ...

We investigate the interplay between energy prices and drilling activities in United States how this relationship has evolved due to shale revolution. hypothesize that (1) there exists significant information spillover prices; (2) amount of transmitted increased since boom; (3) natural gas market is increasingly important transmitter rise unconventional oil production. Using connectedness index...

An axisymmetric full Navier-Stokes computational fluid dynamics study is conducted to examine nozzle exhaust jet plume effects on the sonic boom signature of a supersonic aircraft. A simplified axisymmetric nozzle geometry, representative of the nozzle on the NASA Dryden NF-15B Lift and Nozzle Change Effects on Tail Shock research airplane, is considered. The computational fluid dynamics code i...