Stabilization of aerodynamically excited turbomachinery with hydrodynamic journal bearings and supports

A method of analyzing the first mode stability and unbalance response of multimass flexible rotors is presented whereby the multimass system is modeled as an equivalent single mass modal model including the effects of rotor flexibility, general linearized hydrodynamic journal bearings, squeeze film bearing supports and rotor aerodynamic cross coupling. Expressions for optimum bearing and support damping are presented for both stability and unbalance response. The method is intended to be used as a preliminary design tool to quickly ascertain the effects of bearing and support changes on rotor-bearing system performance

Nickel base coating alloy

Zirconium is added to a Ni-30 Al (beta) intermetallic alloy in the range of 0.05 w/o to 0.25 w/o. This addition is made during melting or by using metal powders. The addition of zirconium improves the cyclic oxidation resistance of the alloys at temperatures above 1100 C

The oxidation and corrosion of ODS alloys

The oxidation and hot corrosion of high temperature oxide dispersion strengthened (ODS) alloys are reviewed. The environmental resistance of such alloys are classified by oxide growth rate, oxide volatility, oxide spalling, and hot corrosion limitations. Also discussed are environmentally resistant coatings for ODS materials. It is concluded that ODS NiCrAl and FeCrAl alloys are highly oxidation and corrosion resistant and can probably be used uncoated

Who Really Benefits from Agricultural Subsidies? Evidence from Field-Level Data

The idea that agricultural subsidies are fully capitalized into farmland values forms the foundation of the argument that subsidies are entitlements and removing them would drastically reduce farmland asset values. Surprisingly little evidence substantiates this claim. Using field-level data and explicitly controlling for potentially confounding variables we find that landlords only capture between 14 – 24 cents of the marginal subsidy dollar. The duration of the rental arrangement has a substantial effect on the incidence. Initially, landlords extract 44 cents of the marginal subsidy dollar, but the incidence falls by 1.5 cents with each additional year of the rental arrangement. This duration effect reveals that rental market frictions play an important role in the farmland rental market.Agricultural and Food Policy,

Analyses of the cloud contents of multispectral imagery from LANDSAT 2: Mesoscale assessments of cloud and rainfall over the British Isles

The author has identified the following significant results. It was demonstrated that satellites with sufficiently high resolution capability in the visible region of the electromagnetic spectrum could be used to check the accuracy of estimates of total cloud amount assessed subjectively from the ground, and to reveal areas of performance in which corrections should be made. It was also demonstrated that, in middle latitude in summer, cloud shadow may obscure at least half as much again of the land surface covered by an individual LANDSAT frame as the cloud itself. That proportion would increase with latitude and/or time of year towards the winter solstice. Analyses of sample multispectral images for six different categories of clouds in summer revealed marked differences between the reflectance characteristics of cloud fields in the visible/near infrared region of the spectrum

Risk and Incentives: A Not-So-Tenuous Trade-off

Risk and Uncertainty,

A HOLISTIC APPROACH TO SUSTAINABILITY BASED ON PLURALISTIC STEWARDSHIP

Environmental Economics and Policy,