NASA Quiet Clean General Aviation Turbofan (QCGAT) program status

The suitability of large engine technology to reduce noise, emissions, and fuel consumption of small turbine engines and develop new technology where required is determined. The design, fabrication, assembly, test, and delivery of the experimental engines to NASA are discussed

Experimental Generation and Observation of Intrinsic Localized Spin Wave Modes in an Antiferromagnet

By driving with a microwave pulse the lowest frequency antiferromagnetic resonance of the quasi 1-D biaxial antiferromagnet (C_2 H_5 NH_3)_2 CuCl_4 into an unstable region intrinsic localized spin waves have been generated and detected in the spin wave gap. These findings are consistent with the prediction that nonlinearity plus lattice discreteness can lead to localized excitations with dimensions comparable to the lattice constant.Comment: 10 pages, 4 figures, accepted for publication in Physical Review Letter

Driven Intrinsic Localized Modes in a Coupled Pendulum Array

Intrinsic localized modes (ILMs), also called discrete breathers, are directly generated via modulational instability in an array of coupled pendulums. These ILMs can be stabilized over a range of driver frequencies and amplitudes. They are characterized by a pi-phase difference between their center and wings. At higher driver frequencies, these ILMs are observed to disintegrate via a pulsating instability, and the mechanism of this breather instability is investigated.Comment: 5 pages, 6 figure

Northwest Iowa On-Farm Research Soybean Population Comparisons

Rising costs of soybean seed combined with herbicide resistant technology fees have caused a re-evaluation of current seeding recommendations. Research conducted by Palle Pedersen, ISU soybean agronomist, has shown there is not a statistical yield difference in yield when there is a final fall stand of 100,000 evenly distributed soybean plants. To evaluate this research on several different locations, cooperators from Sioux, Lyon, and Osceola counties, in northwest Iowa, participated in comparing two populations of soybean seeding rates. A study looking at three populations was also conducted at the Northwest Research Farm

Northwest Iowa On-Farm Research

Northwest Iowa On-Farm Research is in its third year of conducting field scale, triple replicated trials. Replication allows for statistical analysis of results, which are shared. Ideas for on-farm research generally come from the farmer-cooperators or from the local field agronomist. The project was established to localize research in northwest Iowa to help farmers answer some of their crop production questions, and to validate small plot research on a whole-field basis

Northwest Iowa On-farm Research Soybean Yield Response to Headline Fungicide

Six years ago the Northwest Iowa On-Farm Research Project was started to cooperate with local farmers to compare crop production methods on a field scale size. Through this project, over 300 replicated comparisons have been done. Beginning in 2012, the Northwest Iowa On-Farm Research project will be recognized as a part of Iowa State University Farmer Assisted Research and Management (FARM) program. This program will also expand to southwest Iowa, north central Iowa, and central Iowa