Chilled aeration to control pests and maintain grain quality during the summer storage of wheat in north central region of Kansas: Presentation

Chilled aeration allows to cool grain, independent of ambient conditions, to "safe" temperatures where insect, fungi, and spoilage is reduced to the minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses, compared to conventional aeration and storage strategies used during the summer storage of wheat in Central Kansas, U.S.A. The research trials were developed in two 1,350 metric ton (t) steel silos in a Farmer’s Cooperative during the summer and fall of 2015 and 2016. One of the silos was chilled and the other was used as a control managed by the Cooperative. Variables evaluated were: grain temperature, moisture content (MC), grain quality, insect development and reproduction rate. The chilling treatment reduced the grain temperature from 28°C- 39°C to a minimum of 17°C- 17.6°C in less than 250 hours. Grain temperatures below 25°C were not possible during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the MC by 0.5%. Reproduction rates of RFB and LGB were significantly reduced by chilled temperatures lower than 17°C. Lower temperatures also reduced insects discovered in probe traps and insect damaged kernels (IDK). The energy cost of the grain chiller was between 0.26 US $/t- 0.32 US$/t higher than ambient aeration.Chilled aeration allows to cool grain, independent of ambient conditions, to "safe" temperatures where insect, fungi, and spoilage is reduced to the minimum. The objective of this research was to evaluate the advantages of using grain chilling to preserve the quality of grain and reduce post-harvest losses, compared to conventional aeration and storage strategies used during the summer storage of wheat in Central Kansas, U.S.A. The research trials were developed in two 1,350 metric ton (t) steel silos in a Farmer’s Cooperative during the summer and fall of 2015 and 2016. One of the silos was chilled and the other was used as a control managed by the Cooperative. Variables evaluated were: grain temperature, moisture content (MC), grain quality, insect development and reproduction rate. The chilling treatment reduced the grain temperature from 28°C- 39°C to a minimum of 17°C- 17.6°C in less than 250 hours. Grain temperatures below 25°C were not possible during the summer using ambient aeration. Minimum variation of MC was observed in the Chilled silo while ambient aeration reduced the MC by 0.5%. Reproduction rates of RFB and LGB were significantly reduced by chilled temperatures lower than 17°C. Lower temperatures also reduced insects discovered in probe traps and insect damaged kernels (IDK). The energy cost of the grain chiller was between 0.26 US $/t- 0.32 US$/t higher than ambient aeration

Performance assessment off a commercial scale solar biomass hybrid dryer for quality seed maize production: Presentation

Though several maize varieties have been developed and introduced over the years in Ghana, farmers still face challenges of access to quality seed maize. Among the major constraints is lack of proper drying systems to quarantee quality of seed produced. Peculiar to most parts of Africa, drying of maize in the open, on bare ground along shoulders of roads is still a common practice in Ghana. In this study, a 5-tonne capacity solar biomass hybrid dryer was developed for drying maize for seed and food/feed in Ghana. Effect of drying air temperature in the dryer on the physiological quality and germination of maize kernels was investigated. Maize grains were dried in the open sun simulating farmers practice and using the dryer at 4 varying levels (L1, L2, L3 and L4) with corresponding heights (0.6m, 1.2m, 1.8m and 2.4m) respectively. Harvested maize at 22.8% moisture content was dried at the varying levels until reaching overall mean moisture content of 12.8 ± 0.2% (wb). Results showed that, drying air temperatures in the dryer increased in accordance with height with lowest mean temperature of 44.4 ± 4.6°C recorded at L1 and mean maximum of 52.8 ± 5.4 °C at L4. The increase in drying temperature at L4 increased kernel stress crack index by an average of 14% and reduced germination by 33%. However, drying temperatures at L1-L3 and in the open sun had no significant effect (p > 0.05) on the germination potential of maize grains. This satisfies the dryer’s potential to be used for drying maize grains for high quality seed production on commercial scale.Though several maize varieties have been developed and introduced over the years in Ghana, farmers still face challenges of access to quality seed maize. Among the major constraints is lack of proper drying systems to quarantee quality of seed produced. Peculiar to most parts of Africa, drying of maize in the open, on bare ground along shoulders of roads is still a common practice in Ghana. In this study, a 5-tonne capacity solar biomass hybrid dryer was developed for drying maize for seed and food/feed in Ghana. Effect of drying air temperature in the dryer on the physiological quality and germination of maize kernels was investigated. Maize grains were dried in the open sun simulating farmers practice and using the dryer at 4 varying levels (L1, L2, L3 and L4) with corresponding heights (0.6m, 1.2m, 1.8m and 2.4m) respectively. Harvested maize at 22.8% moisture content was dried at the varying levels until reaching overall mean moisture content of 12.8 ± 0.2% (wb). Results showed that, drying air temperatures in the dryer increased in accordance with height with lowest mean temperature of 44.4 ± 4.6°C recorded at L1 and mean maximum of 52.8 ± 5.4 °C at L4. The increase in drying temperature at L4 increased kernel stress crack index by an average of 14% and reduced germination by 33%. However, drying temperatures at L1-L3 and in the open sun had no significant effect (p > 0.05) on the germination potential of maize grains. This satisfies the dryer’s potential to be used for drying maize grains for high quality seed production on commercial scale

Ozonation systems as a non-chemical alternative for stored grain protection

The use of ozone as a non-chemical alternative in stored grain protection was studied by conducting scale-up demonstrations using a fixed bed ozonation system and developing a semi-continuous counterflow and a continuous flow ozonation treatment system. The objectives of this research were to determine the efficacy of ozonation to control insect pests without affecting end-use quality; to prove the concept of the semi-continuous counterflow ozonation system to ozonate grain at a faster rate and quantify its effect on mold growth reduction; to evaluate the efficacy of a modified screw conveyor for pest control by treating grain in a continuous-flow ozonation treatment system; and to determine technically feasible scale-up configurations of each ozonation treatment system including which is most cost-effective. Ozonation treatment in fixed bed systems resulted in 100% insect mortality for adults of maize weevil (MW) and red flour beetle (RFB) with no end-use quality effect on grain. The semi-continuous counterflow system was proven as an effective system to treat grain based on control of three key variables: airflow, ozone mass flow, and exposure time. Mold in stored grain was reduced by more than 50% for ozone cumulative CTP between 340 to 565 ppm-h. The continuous flow system proved to be effective resulting in 100% insect mortality for adult MW and RFB with an average grain retention time of 1.8 minutes and ozone concentration of 47,800 ppm. The scale-up and economic analysis showed that continuous flow ozonation was predicted to have the lowest treatment cost of 1.21 $/MT compared to fixed bed ozonation (1.33$/MT) and semi-continuous counterflow ozonation (2.72 $/MT) when treating 1,272 MT of grain. Also, continuous flow ozonation was 55$/MT. Despite the higher treatment cost of ozonation, fixed bed, semi-continuous counterflow and continuous flow treatment systems can be scaled up in a technically feasible and economically viable manner within the limits of available generator capacities. Thus, ozonation can be used commercially by farmers, grain processors and seed producers as a non-chemical alternative for stored grain protection

Efficacy of fixed bed ozonation treatment to control insects in stored bulk grain

Scale-up demonstration trials were conducted at the pilot bin facility of the Purdue University Post-Harvest Education and Research Center in June 2005, August 2006, July 2007, and October 2008 with conventional yellow maize and at a popcorn storage facility in July 2005 and 2006. The primary objective of these trials was to determine the efficacy of ozonation to control insect pests without affecting end-use quality. The setup consisted of generating ozone at a constant rate with commercially available generators, introduction in the headspace, drawdown to the plenum with a fan with a minimum air velocity through the grain of 0.03 m/s, re-circulation back into the headspace or exhausting from the plenum into another bin. Ozonation was done to attain an ozone concentration of 50 ppm in the plenum to be maintained for a period of 72 h (3,600 ppm-h). When this concentration was not achieved, an ozone concentration-time product of 3,600 ppm-h was aimed for extending the time to expose the grain mass to the same treatment effect to achieve 100% insect mortality. The trials were performed using insect bioassays with adults of maize weevil (MW) and red flour beetle (RFB). Insect mortality was essentially 100% for both MW and RFB. The concept of two phases of ozonation and the airflow rates needed to achieve the required treatment levels of 3,600 ppm-h were investigated. The trials at the popcorn facility confirmed that end-use parameters of popcorn were not affected

RD50 Status Report 2008 - Radiation hard semiconductor devices for very high luminosity colliders

The objective of the CERN RD50 Collaboration is the development of radiation hard semiconductor detectors for very high luminosity colliders, particularly to face the requirements of a possible upgrade scenario of the LHC.This document reports the status of research and main results obtained after the sixth year of activity of the collaboration