Pollution reduction technology program for turboprop engines

The reduction of CO, HC, and smoke emissions while maintaining acceptable NO(x) emissions without affecting fuel consumption, durability, maintainability, and safety was accomplished. Component combustor concept screening directed toward the demonstration of advanced combustor technology required to meet the EPA exhaust emissions standards for class P2 turboprop engines was covered. The combustion system for the Allison 501-D22A engine was used, and three combustor design concepts - reverse flow, prechamber, and staged fuel were evaluated

Analytical study of the frequency response function of a nonlinear spring damper system

A spring damper system with a nonlinear damping element is investigated using the Volterra series method to study the system frequency response function (FRF) characteristics. The relationship between the FRF and the characteristic parameters of the nonlinear damper is determined to produce an analytical description for the system FRF. Simulation studies are used to verify the theoretical analysis. These results provide an important basis for the FRF based analysis and design of nonlinear spring damper systems in the frequency domain

Electron Interactions and Transport Between Coupled Quantum Hall Edges

We examine the effects of electron-electron interactions on transport between edge states in a multilayer integer quantum Hall system. The edge states of such a system, coupled by interlayer tunneling, form a two-dimensional, chiral metal at the sample surface. We calculate the temperature-dependent conductivity and the amplitude of conductance fluctuations in this chiral metal, treating Coulomb interactions and disorder exactly in the weak-tunneling limit. We find that the conductivity increases with increasing temperature, as observed in recent experiments, and we show that the correlation length characterising conductance fluctuations varies inversely with temperature.Comment: 4 pages, 2 figures, typos corrected, Ref. 17 added, minor changes made for publicatio

Pneumatic shutoff and time-delay valve operates at controlled rate

Shutoff and time delay valve, which incorporates a metering spool that moves at constant velocity under pneumatic pressure and spring compression, increases fluid-flow area at a uniform rate. Diaphragm areas, control cavity volume, and bleed-orifice size may be varied to give any desired combination of time delay and spool travel time

An experimental test of Rubinstein's bargaining model

This paper offers an experimental test of a version of Rubinstein’s bargaining model in which the players’ discount factors are unequal. We find that learning, rationality, and fairness are all significant in determining the outcome. In particular, we find that a model of myopic optimization over time predicts the sign of deviations in the opening proposal from the final undiscounted agreement in the previous period rather well. To explain the amplitude of the deviations, we then successfully fit a perturbed version of the model of myopic adjustment to the data that allows for a bias toward refusing inequitable offers

Planning for Planning - Coal: Issues for the Eighties

This Collaborative Paper contains the technical papers presented at IIASA's Task Force Meeting held at the Institute in November 1980 entitled "Planning for Planning -- Coal: Issues for the Eighties", This meeting was part of a research program at IIASA under the generic title "Issues for the Eighties" in which systems analysts and managers from a given industry met to exchange ideas and information, as well as to explore and develop a strategy of using systems analysis, rather than using it merely as a tool to be brought in for certain well-defined problems. The subject of the task force meeting was to explore the use of systems analysis in the planning of new capacity for deep mining in hard coal. In fact, the planning of any major project or enterprise, but especially a colliery is, in itself, an extremely complex process which, by definition, requires planning, i.e., planning must itself be planned. Hence the title of this seminar. The discussion was attended by 17 representatives from 7 countries, and 13 papers were presented or tabled at the meeting

Velocity weakening and possibility of aftershocks in nanofriction experiments

We study the frictional behavior of small contacts as those realized in the atomic force microscope and other experimental setups, in the framework of generalized Prandtl-Tomlinson models. Particular attention is paid to mechanisms that generate velocity weakening, namely a decreasing average friction force with the relative sliding velocity.The mechanisms studied model the possibility of viscous relaxation, or aging effects in the contact. It is found that, in addition to producing velocity weakening, these mechanisms can also produce aftershocks at sufficiently low sliding velocities. This provides a remarkable analogy at the microscale, of friction properties at the macroscale, where aftershocks and velocity weakening are two fundamental features of seismic phenomena.Comment: 8 pages, 7 figure

Assessing the sociology of sport: On sports mega-events and capitalist modernity

On the 50th anniversary of the ISSA and IRSS, one of the leading international scholars on sport and consumer culture, John Horne, considers the trajectory and challenges of research on sports mega-events and their place in capitalist modernity. In anchoring work on this topic in Roche’s definition of mega-events, Horne notes that sports mega-events are important symbolic, economic, and political elements in the orientation of nations to stake their place in global society. Fundamental issues about the concept of ‘mega-event’ pose challenges for scholars as questions remain over what qualifies as a sports mega-event and how ‘lived experience’ with such events transacts with media spectacularization and characterization. The essay closes by posing broader questions for further investigation about the economic, political, and social risks and benefits of sports mega-events and how these events may portend and relate to changing relations of economic and political power on a global scale

Report of an IIASA Seminar on Systems Analysis in the Coal Industry Held in Szczyrk, Poland, 6-9 November 1979

This paper summarizes the proceedings of the IIASA seminar that was held in Poland in November 1979 to discuss the results of collaborative work under the generic title "Coal -- Issues for the Eighties" and to establish a general policy and plan for the future and presents the main conclusions. Three main topics were discussed during this seminar: Organization, Management and Computers; Planning for Planning; and Environmental Problems. This paper covers the first two topics in some detail. The papers themselves are available separately as an IIASA Collaborative Paper, CP-80-23. The presentations and discussion on environmental issues are being issued separately as CP-80-24. All the proceedings will be published as IIASA Collaborative Papers