Search Results

You are looking at 1 - 9 of 9 items for :

  • "duty cycle" x
  • Refine by Access: All x
Clear All
Free access

Marc W. van Iersel and David Gianino

lights on and off at high frequency (10,000 s of times per second). Within each on/off cycle, the fraction of time that the LEDs are on (duty cycle) can be precisely controlled. Reducing the duty cycle creates the perception of dimming, even though in

Free access

Marc W. van Iersel, Geoffrey Weaver, Michael T. Martin, Rhuanito S. Ferrarezi, Erico Mattos, and Mark Haidekker

(top) and a simplified diagram of the duty cycle control board (bottom). A fluorometer is used to measure the quantum yield of photosystem II and the datalogger calculates the electron transport rate from this and the photosynthetic photon flux density

Free access

Matthew Rogoyski, Alvan Gaus, Israel Broner, and Thomas Mourey

An evaporative cooling system for apple trees was implemented. The system is automated to conserve irrigation water. The automation is based on the digital, integrated thermometer and thermostat chip embedded in the artificial fruit. The thermometer–thermostat chip drives a solid state relay. The relay controls a solenoid operated valve. A typical duty cycle consisted of 1 to 2 minutes of wetting (water on) to 4 to 10 minutes drying (water off). Differences in the length of duty cycles between individual chips were observed. The reliability of the system was adequate. The waterproofing of the system's electrical components was its weak point. Irrigation water deposits accumulated on the apple fruit surface during the growing season were readily removable with a simulated brush technique.

Open access

Lauren Fessler, Amy Fulcher, Dave Lockwood, Wesley Wright, and Heping Zhu

. The reason for this difference is that the intelligent spray system controls individual nozzle flow rates with duty cycles of PWM solenoid valves attached to their corresponding nozzles to match sectional canopy foliage volume. To prevent trees from

Full access

Hyun-Gyun Yuk, Benjamin R. Warren, and Keith R. Schneider

per character at 30 μs with a duty cycle of 25%. Two lines of alphanumeric code were etched on the surface of each tomato as follows: “TOMATO” (line one) and “30USUSA” (line two) ( Fig. 1B ). For the pilot plant study, the conveyor line speed was 150

Open access

Lauren Fessler, Amy Fulcher, Liesel Schneider, Wesley C. Wright, and Heping Zhu

characteristics of the detected crop. PWM technology uses duty cycle rather than travel speed, spray pressure, or nozzle size to vary the spray rate, and it has been proven to achieve uniform spray coverage in field conditions ( Grella et al., 2021 ). With the

Full access

Preeti Sood, Chris Ference, Jan Narciso, and Ed Etxeberria

. Individual fruit were placed against a PVC rectangular frame stabilized 10 cm from the laser's output. The energy level used was the recommended 0.000752 W/dot per 35-μs exposure with a 25% duty cycle range. Differences in applied energy are expressed by

Free access

Ruining Li, Wenwen Huang, Xiaoxiao Wang, Xiaoying Liu, and Zhigang Xu

, Netherlands Jao, R.C. Fang, W. 2001 Adjusting frequency and duty cycle to promote growth of potato plantlets in vitro using super-bright red and blue LEDs. Proc. Intl. Symp. Design Environ. Control Trop. Subtrop. Greenhouses 4:15–18 Jao, R.C. Fang, W. 2004

Free access

character at 35 μs with a duty cycle range of 25%, spot inoculated with a five-strain cocktail of Rifampicin-resistant Salmonella , and swabbed with commercial tomato wax. Five different sequences of laser label, inoculum, and wax application were evaluated