Determination of Entrapment Victim Extrication Forces with and without Use of a Grain Rescue Tube.

The forces required to extricate a test mannequin from a grain mass when buried at different depths with and without a grain restraint system were determined. When there was no grain restraint system in place, the vertical force required to pull the mannequin from the grain when it was buried waist deep and to the underarms was 1259 and 1766 N (283 and 397 lb(f)), respectively. It increased to 1584 N (356 lb(f)) (+26%) and 2153 N (484 lb(f)) (+22%), respectively, with the restraint in place due to the changes in grain properties brought about by the insertion of the rescue tube. It was concluded that the use of a grain restraint during extrication of a victim does not reduce the forces required and that forcefully pulling an entrapped victim, especially with mechanical assistance, with or without a grain restraint system could result in severe injuries and possible death due to the forces exerted on the victim. The authors recommend that these findings be incorporated into current grain extrication training for emergency first responders.

Determination of effort required to insert a rescue tube into various grain types.

This study was conducted to quantify the forces required to insert the individual panels of a grain rescue tube into four grains of varying moisture contents. The study was conducted to address issues raised by emergency rescue personnel involved with extrication of victims entrapped in grain using a fabricated or commercially available grain containment system. These rescue aids are used to separate or protect the victim from the grain mass, enabling safe rescue. Conclusions drawn from the study included documentation that as the moisture content of the grain increases, the amount of resistance against tube insertion increases substantially. It was found that although the moisture content may be similar across several types of grain, the amount of work required to insert a rescue tube into the grain can vary. It was also concluded that the cohesiveness, angle of internal friction, and static coefficient of friction of the grain on the tube surface, which vary with moisture content and type of grain, were primary factors affecting the amount of effort needed to insert the tube. This article recommends that a consensus standard be developed covering the design and testing of grain rescue tube containment systems.

Summary of prior grain entrapment rescue strategies.

Entrapment in flowable agricultural material continues to be a relevant problem facing both farmers and employees of commercial grain storage and handling operations. While considerable work has been done previously on the causes of entrapment in grain and possible preventative measures, there is little research on the efficacy of current first response or extrication techniques. With the recent introduction of new grain rescue equipment and training programs, it was determined that the need exists to document and summarize prior grain rescue strategies with a view to develop evidence-based recommendations that would enhance the efficacy of the techniques used and reduce the risks to both victims and first responders. Utilizing the Purdue University Agricultural Entrapment Database, all data were queried for information related to extrication of victims from grain entrapments documented over the period 1964-2006. Also analyzed were data from other sources, including public records related to entrapments and information from onsite investigations. Significant findings of this study include the following: (1) between 1964 and 2006, the number of entrapments averaged 16 per year, with the frequency increasing over the last decade; (2) of all cases documented, about 45% resulted in fatality; (3) no less than 44% of entrapments occurred in shelled corn; (4) fatality was the result in 82% of cases where victims were submerged beneath the grain surface, while fatality occurred in 10% of cases where victims were only partially engulfed; (5) the majority of rescues were reported to have been conducted by untrained personnel who were at the scene at the time of entrapment; and (6) in those cases where the rescue strategies were known, 56% involved cutting or punching holes in the side walls of the storage structure, 19% involved utilizing onsite fabricated grain retaining walls to extricate partially entrapped victims, and the use of grain vacuum machines as a rescue strategy was on the increase. Among the recommendations growing out of the study are these: (1) conduct further tests on the efficacy of grain rescue strategies, including the use of recently introduced grain rescue tubes and grain vacuum machines; (2) incorporate the findings into future first responder training programs; and (3) enhance the first response skills of personnel working at grain storage facilities, both on-farm and at commercial operations.

Economics of integrated insect management in stored corn.

Insects can cause substantial damage to stored grain. In addition, consumers and therefore food processors are increasingly interested in chemical-free products. Integrated pest management (IPM) may increase farmers' profits while reducing their use of pesticides. This study uses a stochastic dynamic programming framework to model the economics of optimal insect control in corn, Zea mays L., stored on-farm with multiple controls conditional on the biophysical conditions of the grain in the bin. We find that for farmers who have a contract with a food processor, where there are quality premiums, the optimal management strategy depends on monitoring the biophysical conditions of the grain and the time period under consideration. For farmers who deliver to the commodity market, their current practices are optimal.

Summary of fatal entrapments in on-farm grain storage bins, 1966-1998.

For over 30 years, Purdue University has maintained a national database of agriculture-related entrapment cases that have occurred in loose agricultural material. At present, 391 documented fatal and non-fatal entrapments from the U.S. and Canada make up the Purdue University Agricultural Entrapment Database. In order to specifically study fatal cases of entrapments in grain bins located on farms, the database was reviewed, 181 cases were identified using specific criteria, and the results were summarized. Approximately five cases per year were identified between 1966 and 1998, representing 18 states and one Canadian province. Entrapments were generally reported more often in the top corn-producing states and during the months of November, December, January, March, and June. In 24% of the cases in which the victim's age was known, the victims were younger than 16. Children and adolescents younger than 16 were more often fatally entrapped in June than in any other month. For cases in which the product was known, corn was the agent of injury in 53% of the cases and was frequently found to be out-of-condition. At the time of entrapment, victims were involved with bin unloading activities in 76% of the cases in which the activity was identified. These findings are being used to design new injury prevention strategies, including educational materials and recommendations for engineering controls that focus on primary causative factors.

Efficacy and fumigation characteristics of ozone in stored maize.

This study evaluated the efficacy of ozone as a fumigant to disinfest stored maize. Treatment of 8.9tonnes (350bu) of maize with 50ppm ozone for 3d resulted in 92-100% mortality of adult red flour beetle, Tribolium castaneum (Herbst), adult maize weevil, Sitophilus zeamais (Motsch.), and larval Indian meal moth, Plodia interpunctella (Hübner) and reduced by 63% the contamination level of the fungus Aspergillus parasiticus Speare on the kernel surface. Ozone fumigation of maize had two distinct phases. Phase 1 was characterized by rapid degradation of the ozone and slow movement through the grain. In Phase 2, the ozone flowed freely through the grain with little degradation and occurred once the molecular sites responsible for ozone degradation became saturated. The rate of saturation depended on the velocity of the ozone/air stream. The optimum apparent velocity for deep penetration of ozone into the grain mass was 0.03m/s, a velocity that is achievable in typical storage structures with current fans and motors. At this velocity 85% of the ozone penetrated 2.7m into the column of grain in 0.8d during Phase 1 and within 5d a stable degradation rate of 1ppm/0.3m was achieved. Optimum velocity for Phase 2 was 0.02m/s. At this velocity, 90% of the ozone dose penetrated 2.7m in less than 0.5d. These data demonstrate the potential usefulness of using ozone in managing stored maize and possibly other grains.

Effect of ingredients and processing parameters on pellet quality.

Rations containing varying ratios of corn, high-oil corn, soybean meal, and mechanically expelled soybean meal were pelleted. The effects of ingredients, conditioning steam pressure, and mixing paddle configuration inside the conditioner on pellet quality were investigated. Ration ingredients strongly affected pellet quality. Increasing the protein content increased the pellet durability, whereas increasing the oil content above 7.5% greatly decreased pellet durability. High-oil corn and mechanically expelled soybean meal produced acceptable pellets when combined with soybean meal and regular corn, respectively. However, poor pellet quality resulted when rations containing high-oil corn and mechanically expelled soybean meal were processed. Increasing the residence time in the conditioner by changing mixing paddle pitch resulted in an average 4.5-point increase in pellet durability indices among 65:35 (wt) corn:soybean meal and 65:35 high-oil corn:soybean meal rations.