Evaluation of Proposed Rocket Engines for Earth-to-Orbit Vehicles

The objective is to evaluate recently analyzed rocket engines for advanced Earth-to-orbit vehicles. The engines evaluated are full-flow staged combustion engines and split expander engines, both at mixture ratios at 6 and above with oxygen and hydrogen propellants. The vehicles considered are single-stage and two-stage fully reusable vehicles and the Space Shuttle with liquid rocket boosters. The results indicate that the split expander engine at a mixture ratio of about 7 is competitive with the full-flow staged combustion engine for all three vehicle concepts. A key factor in this result is the capability to increase the chamber pressure for the split expander as the mixture ratio is increased from 6 to 7

Air transportation technology program at Ohio University, 1983

The purpose is to provide a research tool, a receiver, such that engineers interested in examining Loran-C performance, usefulness, and other properties will have a flexible, modifiable, and well-known piece of receiving hardware. The significant improvements to the Loran-C receiver are summarized

The topology of deformation spaces of Kleinian groups

Let M be a compact, hyperbolizable 3-manifold with nonempty incompressible boundary and let AH(\pi_1(M)) denote the space of (conjugacy classes of) discrete faithful representations of \pi_1(M) into PSL 2 (C). The components of the interior MP(\pi_1(M)) of AH(\pi_1(M)) (as a subset of the appropriate representation variety) are enumerated by the space A(M) of marked homeomorphism types of oriented, compact, irreducible 3-manifolds homotopy equivalent to M. In this paper, we give a topological enumeration of the components of the closure of MP(\pi_1(M)) and hence a conjectural topological enumeration of the components of AH(\pi_1(M)). We do so by characterizing exactly which changes of marked homeomorphism type can occur in the algebraic limit of a sequence of isomorphic freely indecomposable Kleinian groups. We use this enumeration to exhibit manifolds M for which AH(\pi_1(M)) has infinitely many components.Comment: 49 pages, published versio

Visual display and alarm system for wind tunnel static and dynamic loads

A wind tunnel balance monitor and alarm system developed at NASA Ames Research Center will produce several beneficial results. The costs of wind tunnel delays because of inadvertent balance damage and the costs of balance repair or replacement can be greatly reduced or eliminated with better real-time information on the balance static and dynamic loading. The wind tunnel itself will have enhanced utility with the elimination of overly cautious limits on test conditions. The microprocessor-based system features automatic scaling and 16 multicolored LED bargraphs to indicate both static and dynamic components of the signals from eight individual channels. Five individually programmable alarm levels are available with relay closures for internal or external visual and audible warning devices and other functions such as automatic activation of external recording devices, model positioning mechanisms, or tunnel shutdown

Multi-Market Trading for Cooperative Resource Management: An Application to Water Pollution and Fisheries

Increasingly, environmental problems are recognized to involve linkages across multiple environmental variables (e.g., pollution and a fishery). Prior work on managing these complex, linked systems generally focuses on efficiency rather than implementation. However, implementation is important and will generally involve changing human behaviors within the multiple economic sectors that impact upon the multiple environmental variables. Tradable permit markets are generally seen as a coordinating mechanism, within a particular regulated sector, that enhances efficiency by incentivizing agents to respond to behavioral choices of others within the sector. However, prior work stops short of coordinating behaviors across multiple sectors for cases where society benefits from regulation in both sectors and one sector harms the other. We analyze a multi-sector permit market involving both the externality-generating sector and the affected sector. This multi-sector market provides a mechanism for agents in one sector to respond to environmental behaviors made within the other sector. Moreover, unlike traditional permit markets in which the regulated externality sector incurs only costs, we show that the multi-sector market generates efficiency gains that may be redistributed using appropriate allocations of initial endowments. Accordingly, the multi-sector market may generate gains that benefit both sectors, resulting in a win-win outcome for both sectors. We use a simple example of a polluted fishery to illustrate the approach.Permit trading, fisheries, pollution, Shapley values, bioeconomics, Environmental Economics and Policy, Resource /Energy Economics and Policy,