Loads technology for supersonic cruise aircraft

A flight program to measure atmospheric turbulence at high altitudes (long wavelengths) in a variety of meteorological conditions is described and some results obtained in high altitude wind shear are discussed. Results are also presented from wind tunnel test programs to measure fluctuating pressures associated with over-the-wing configurations. A flexible aircraft take off and landing analysis and an active control landing gear analysis, are developed and their capabilities are described. Efforts to validate these analyses with experimental data are also discussed as well as results obtained from parametric studies

The use of magnetic torquing for control moment gyro desaturation

Magnetic torquing system for control moment gyro momentum dumpin

Urban Goods Movement and Local Climate Action Plans: Assessing Strategies to Reduce Greenhouse Gas Emissions from Urban Freight Transportation

This report examines how freight transport/goods movement has been addressed in U.S. city climate action planning. Transportation generally is a major contributor of greenhouse gas (GHG) emissions, and freight transport represents a growing component of transportation’s share. Almost all climate action plans (CAPs) address transportation generally, but we wished to focus on efforts to reduce GHG emissions from freight transport specifically. We analyzed 27 advanced local CAPs to determine the degree to which freight transport was targeted in goals and strategies to reduce GHG emissions. We found only six CAPs that included direct measures or programs to reduce freight emissions. Many of the CAPs mentioned general transportation objectives such as lowering vehicle miles traveled or reducing emissions from city-owned vehicle fleets, but most did not include strategies or actions that explicitly targeted freight transport. We identified the specific strategies and actions that cities are taking to address GHG emissions from freight transport, such as working with the freight community to promote anti-idling and encourage transitions to electric and alternative fuel delivery vehicles. We also analyzed freight transport plans relevant for the same cities, and found that most do not explicitly mention reducing GHG emissions. Most of the freight plans are focused on improving reliability and efficiency of freight movement, which would likely have the ancillary benefit of reducing GHG emissions, but that goal was not explicitly targeted in most of these plans. Based on our findings, we recommend that cities specifically target freight transport goals and strategies in their CAPs and better coordinate with planners developing freight transport plans to identify GHG emission reduction approaches

Some effects of tip fins on wing flutter characteristics

A wind tunnel investigation has been conducted over the Mach number range from about 0.6 to 1.2 to determine the effects of large tip fins on the flutter characteristics of a swept wing. The basic wing configuration had an aspect ratio of 0.95, leading-edge sweep of 40 deg 0, and trailing-edge sweep of 21 deg. Two of these configurations were modified with tip fins of 60 deg dihedral and had effective aspect ratios of 1.5 and 2.2. In general, the results indicate that the addition of tip fins reduces the flutter speed, with the larger fin having the greater effect. Comparison of the experimental flutter speeds at Mach numbers between 0.60 and 0.90 with calculated values obtained by using doublet-lattice unsteady aerodynamic theory was good. Analytical results where structural and aerodynamic effects of the tip fins were isolated indicated that the reduction in flutter speed produced by the addition of the fins was caused by both effects, with the structural effect being the more pronounced

Synthesis of aircraft structures using integrated design and analysis methods

A systematic research is reported to develop and validate methods for structural sizing of an airframe designed with the use of composite materials and active controls. This research program includes procedures for computing aeroelastic loads, static and dynamic aeroelasticity, analysis and synthesis of active controls, and optimization techniques. Development of the methods is concerned with the most effective ways of integrating and sequencing the procedures in order to generate structural sizing and the associated active control system, which is optimal with respect to a given merit function constrained by strength and aeroelasticity requirements

Interbank tiering and money center banks

This paper provides evidence that interbank markets are tiered rather than flat, in the sense that most banks do not lend to each other directly but through money center banks acting as intermediaries. We capture the concept of tiering by developing a core-periphery model, and devise a procedure for tting the model to real-world networks. Using Bundesbank data on bilateral interbank exposures among 1800 banks, we find strong evidence of tiering in the German banking system. Econometrically, bank-specific features, such as balance sheet size, predict how banks position themselves in the interbank market. This link provides a promising avenue for understanding the formation of financial networks.Interbank market ; Banks and banking, Central - Germany

Interbank tiering and money center banks

Interbank markets are tiered rather than flat, in the sense that many banks do not lend to each other directly but through money center banks which act as intermediaries. This paper captures the notion of tiering by designing a core-periphery model and develops a procedure for fitting an empirical network to this model. We find strong evidence of tiering for the German banking system, using bilateral interbank exposures among 1,800 banks. Moreover, bank-specific features, such as bank size, help explain how banks position themselves in the interbank market, suggesting that models with heterogenous banks could help shed light on how financial networks are formed.Interbank market

City-regionalism as a politics of collective provision : regional transport infrastructure in Denver, USA

The rise of the city-region concept has focused attention on the nature of territorial politics underpinning city-regionalism. This paper investigates the relationship between territorial politics, city-regionalism and the collective provision of mass transport infrastructure in the USA. It deploys a case study of the Denver region, examining the state and governance structures driving forward FasTracks, a long-term project to expand the Denver Regional Transportation District’s light and commuter rail system. FasTracks represents a programme to retrofit the Denver city-region for integrated mass transit but its funding has fostered tensions around new regionalist governance arrangements. The paper uses the findings of the case study to reflect upon the balance of bottom–up versus top–down geopolitical forces shaping the landscape of city-regionalism in the USA. It emphasises the variety of ways in which struggles around infrastructure provision shape the emergence of new city-regionalist structures inside the competition state

The environmental communication forum

The establishment, Modus operandi and aims of the Environmental Communicators Forum in the greater Durban area is described