Study and development of acoustic treatment for jet engine tailpipes

A study and development program was accomplished to attenuate turbine noise generated in the JT3D turbofan engine. Analytical studies were used to design an acoustic liner for the tailpipe. Engine ground tests defined the tailpipe environmental factors and laboratory tests were used to support the analytical studies. Furnace-brazed, stainless steel, perforated sheet acoustic liners were designed, fabricated, installed, and ground tested in the tailpipe of a JT3D engine. Test results showed the turbine tones were suppressed below the level of the jet exhaust for most far field polar angles

Economic Emergency Program: St. Cloud Household Refrigeration and Home Freezer Manufacturing Plant Closure (Electrolux)

On January 30, 2018, Electrolux announced the closure its manufacturing facility in St. Cloud, Minnesota. The plant currently has 860 employees. Their jobs will be lost once Electrolux completes its closure as planned in 2019. Electrolux plans to invest in its Tennessee and South Carolina plants. Upright freezer production will move to South Carolina. There will likely be few viable opportunities for local workers at the Electrolux facility to re-locate to South Carolina. St. Cloud area decision-makers will benefit from timely information regarding the potential economic impact of the closure. In response, University of Minnesota Extension and the St. Cloud State University School of Public Affairs Research Institute have prepared this economic emergency report. This report is presented with support from the EDA Center at the University of Minnesota-Crookston

Nitrite Generation in Interleukin-4—Treated Human Macrophage Cultures Does Not Involve the Nitric Oxide Synthase Pathway

The search continues for high-output nitric oxide biosynthesis in human macrophages analogous to murine phagocytes. Recently, generation of nitrite in culture supernatants of human macrophages exposed to interferon-γ and interleukin-4 (IFN-γ/IL-4) was reported. The present study reproduces these findings and shows that L-arginine is not consumed and L-citrulline is not produced during this process. Furthermore, the biosynthesis of the obligatory cofactor tetrahydrobiopterin is not coinduced. These biochemical data provide support against a nitric oxide synthase contribution to nitrite accumulation. Nitrite was generated from nitrate salts even in cell-free media. Nitric oxide synthase activity but not nitrate reduction depended on molecular oxygen. Nitrite accumulation in experiments with IFN-γ/IL-4 in human monocytes appears to be an in vitro artifact produced by nitrate-reducing activities contained in cytokine preparation