The Infrared Behavior of One-Loop Gluon Amplitudes at Next-to-Next-to-Leading Order

For the case of $n$-jet production at next-to-next-to-leading order in the QCD coupling, in the infrared divergent corners of phase space where particles are collinear or soft, one must evaluate $(n+1)$-parton final-state one-loop amplitudes through \Ord(\eps^2), where \eps is the dimensional regularization parameter. For the case of gluons, we present to all orders in \eps the required universal functions which describe the behavior of one-loop amplitudes in the soft and collinear regions of phase space. An explicit example is discussed for three-parton production in multi-Regge kinematics that has applications to the next-to-leading logarithmic corrections to the BFKL equation.Comment: Latex, 14 pages, no figure

Grain Drying With Supplemental Solar Heat

The use of solar energy for drying shelled corn was investigated. In a three-year field study, energy re-quirements of a conventional low-temperature electric drying installation were compared with those of a similar system supplemented with the output of a simple, inex-pensive solar collector

Breakage Susceptibility of Blended Corn

A test of the breakage susceptibility of blended corn was conducted with four moisture levels of dry corn (8, 9, 11, and 8.9% desiccant) blended with 24.4% moisture corn to two theoretical moisture levels (15.5 and 20%). The study showed that blending wet and dry corn increases the Stein breakage 0.74 to 4.47 points for a 15.5% blend and 1.54 to 10.6 points for a 20% moisture blend. The breakage in local handling due to blending wet and dry corn is likely to be from 0.1 to 1.7%, which will probably not result in a discount at the time of sale

Corn Grain Drying Using Corn Stover Combustion and CHP Systems

Post-harvest drying of shelled corn grain requires large amounts of fossil fuel energy. In 2004, it was estimated that the upper Midwest consumed more than $1.4 billion of fossil fuels to dry$19.7 billion of corn grain. Over the long term, drying corn with fossil fuels may become cost prohibitive due to limited fuel reserves. To address future energy concerns for grain dryers, this study evaluated the potential use of combined heat and power (CHP) systems that use the combustion of corn stover both to produce heat for drying and to generate electricity for fans, augers, and control components. Net present value (NPV) cost estimates were determined for two continuous-flow dryers: a relatively small on-farm dryer (8.9 Mg h-1), and a larger dryer more common to grain elevators (73 Mg h-1). For each dryer, three levels of assumed stover price were used: $15,$25, and $35 per dry Mg for the small dryer, and$30, $45, and$60 per dry Mg for the larger dryer (includes payments to farmer and off-farm transport costs). Compared to equivalently sized fossil fuel-fired dryers, both the small and large CHP dryers were found to be more economical over the long term. Twenty-year NPV cost savings and breakeven points were estimated to be $63,523 and 14.3 years for the small CHP dryer ($25 Mg-1 stover) and $1,804,482 and 7.5 years for the large dryer ($45 Mg-1 stover). Sharing CHP infrastructure with other processes requiring heat that extend seasonal use can reduce payback periods significantly and provide broader efficiency benefits. Sensitivity analysis found cost savings to be most sensitive to fluctuations in fossil fuel costs, followed by annual use of dryer equipment

Preserving the Iowa Corn Crop: Energy Use and CO2 Release

A study was undertaken to estimate energy use and CO2 release due to postharvest preservation of the 38.8 × 106-Mg (1.52 ×109-bu) Iowa corn crop. About 87% of the crop is artificially dried. Other preservation methods include cribbing ear corn (7%), oxygen-limiting storage (5%) and chemical preservative treatment (1%). Preservation of the corn crop requires, in total, 18 200 TJ of energy and releases 1614 Gg of CO2. Combustion of fuel (liquefied petroleum or natural gas) and electricity accounted for 77 and 10% of total energy use, respectively. CO2 from combustion of fuel and generation of electricity accounted for 57 and 32% of the CO2 release, respectively. Preservation methods varied in total energy use and CO2 release from farm natural-air drying at 1020 MJ/Mg corn and 262 kg CO2/Mg corn to chemical preservative treatment at 116 MJ/Mg corn and 9.3 kg CO2/Mg corn

Drying Corn with Coal on Iowa Farms

A study was conducted to determine the feasibility of using Iowa coal as a fuel source for on-farm corn drying. Two furnaces tested operate at 50 to 55% efficiency. Two existing on-farm systems were described. A cost analysis showed energy costs for coal were less than for propane, but heating system costs are about equal and do not favor a shift to coal

Mixing Beef Feed Rations Containing Distillers Wet Grains

The flexibility of distillers grains has made it a major substitute for corn in beef feed rations. However, producers are having issues with feeding wet distillers grains. This study addresses three major mixing conditions: ingredient addition order, mixing time, and mixer design. The addition orders considered were hay-corn-protein-DWG and hay-DWG-protein-corn. Horizontal and vertical mixers were tested at mix times of 3, 5, and 7 min mixing a beef finishing ration containing wet distillers grains. Test results were obtained using total mixed ration and Pennsylvania State University Particle Separator analyses. Results showed that the 3-min mixing time is sufficient, thus when adding distillers grains, longer mix times are not needed. The hay- corn-protein- DWG ingredient addition order is recommended for both mixers when using liquid additives in the ration in order to avoid unwanted bundle formation. Finally, the two mixer designs were both adequate in mixing a wet distillers grains ration

H-->ggg(gqqbar) at Two Loops in the Large-M_t Limit

We present a calculation of the two-loop helicity amplitudes for the processes H-->ggg and H-->gqqbar in the large-M_t limit. In this limit the calculation can be performed in terms of one-loop diagrams containing an effective Hgg operator. These amplitudes are required for the next-to-leading order (NLO) corrections to the Higgs transverse momentum distribution and the next-to-next-to-leading order (NNLO) corrections to the Higgs production cross section via the gluon fusion mechanism.Comment: 13 pages Latex, 2 figure