Microprocessor controlled low-temperature corn drying system
Abstract Hardware, software and control criteria of microcomputer control of low-temperature corn drying are discussed. The ambient temperature and relative humidity were monitored by the microcomputer as a measure of the input conditions. A model of the low-temperature drying process stored in the memory enabled the microcomputer to calculate the grain moisture contents at assigned locations in the bin. Control decisions were then based on predicted moisture levels and on predicted or measured grain temperatures. Simulation results showed that the proposed system can save energy from 5 to 31% compared with high-temperature drying, depending upon the weather conditions.
Microcomputer control of a process to regenerate saturated desiccants
Abstract This paper describes a method of data acquisition and process control for a desiccant regeneration system using an Apple IIe microcomputer. It also provides circuit diagrams for multiplexing thermocouples and activating a modutrol motor and a solenoid valve for process control. The main program for data acquisition and control is written in Fortran language and utilizes several subroutines written in Assembly language of the 6502 microprocessor for data collection and control. A flow chart for the algorithm along with some details of system control are provided. Using this technique, over 600 h of data have been collected in steps of 10 min.
Effect of Soybean Cyst Nematode (Heterodera glycines) on Yield of Resistant and Susceptible Soybean Cultivars Grown in Ohio.
Soybean (Glycine max) producers in Ohio rarely use soybean cyst nematode (Heterodera glycines, SCN)-resistant cultivars because of concerns over limited yield potential and lack of resistance to Phytophthora sojae. A two-year study was initiated to determine grain yield and nematode population increase on soybean cyst nematode-resistant cultivars in maturity groups II and III in production fields. Sites differed in soil texture, nematode densities, and P. sojae infestation at a number of locations in Ohio. Soil was assayed for nematode densities before planting and at harvest. Yields of resistant cultivars averaged 0% to 18% higher than those of susceptible cultivars in fine-textured soils with average preplant populations ranging from 463 to 14,330 SCN eggs/100 cm(3) soil. In coarse-textured soils, yields of susceptible cultivars were 21% to 56% less than the resistant cultivars with average preplant densities ranging from 1,661 to 15,558 SCN eggs/100 cm(3) soil. The reproductive index ranged from 0.1 to 5.5 for resistant cultivars and 0.4 to 112 for susceptible cultivars. In 1993, yield of P. sojae-susceptible, nematode-resistant 'Asgrow A 3431' was as high as yield of the P. sojae-resistant, nematode-susceptible cultivar 'Resnik' in a Phytophthora-infested field. The nematode-resistant cultivars Madison Experimental 131527 and Asgrow A3431 had higher yields than AgVenture AV1341 and susceptible cultivars Resnik and Kenwood when compared over five nematode-infested sites. Nematode-resistant cultivars were found to be excellent alternatives to currently grown susceptible cultivars for managing SCN where group III cultivars are used. However, better cultivar alternatives may be needed for sites with combined Phytophthora root rot and cyst nematode problems.