38,475 research outputs found
An automatically-shifted two-speed transaxle system for an electric vehicle
An automatic shifting scheme for a two speed transaxle for use with an electric vehicle propulsion system is described. The transaxle system was to be installed in an instrumented laboratory propulsion system of an ac electric vehicle drive train. The transaxle which had been fabricated is also described
Taxation and Corporation Finance
This paper analyzes the effects of the federal tax structure on corporate financial and investment behavior. We first develop a model of corporate behavior given taxes, taking into account both uncertainty and costs of bankruptcy. Simpler models abstracting from bankruptcy costs had clear counterfactual implications. The forecasts from our model proved to be consistent with both the observed cross-sectional variation in debt-equity ratios and the time series pattern of debt-equity ratios (data that were constructed in the paper). We then attempted to measure the efficiency costs created by corporate tax distortions as implied by the model. The forecasted efficiency cost of the distortion favoring debt finance seemed to be quite large, while the tax distortion affecting investment seemed to be less important than others have claimed. The paper concludes with a study of the efficiency implications of various proposed corporate tax changes.
Liquid-hydrogen rocket engine development at Aerojet, 1944 - 1950
This program demonstrated the feasibility of virtually all the components in present-day, high-energy, liquid-rocket engines. Transpiration and film-cooled thrust chambers were successfully operated. The first liquid-hydrogen tests of the coaxial injector was conducted and the first pump to successfully produce high pressures in pumping liquid hydrogen was tested. A 1,000-lb-thrust gaseous propellant and a 3,000-lb-thrust liquid-propellant thrust chamber were operated satisfactorily. Also, the first tests were conducted to evaluate the effects of jet overexpansion and separation on performance of rocket thrust chambers with hydrogen-oxygen propellants
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Texas coastal zone biotopes : an ecography : interim report for the Bay and Estuary Management Program (CRMP)
November 1972Because esthetics, biological environment and physiography are so interrelated and have changeable meanings in various environments, we are obligated to think of the environment in terms of biological change, as environmental protection is presently a basis for much dialogue and sometimes controversy. To do this we have chosen an old concept and adapted it to identify the relationships among biological communities that may be changed when man or nature modifies the coastal environment. The chosen term is BIOTOPE, which is defined in Webster's as a region uniform in environmental conditions and in populations of animals and plants for which it is the habitat. Although the biological environment may appear to the layman as either diverse or uniform and without pattern, there are recognizable biotic assemblages that have some degree of relationship in their composition. Such recognizable assemblages may cover wide areas, such as the extensive turtle grass flats, or may be discrete small units, such as an oyster reef. Thus we have adapted the term BIOTOPE to identify such assemblages and initially suggest the following eighteen examples listed in Table 1. Thirteen of them plus an overview are illustrated. ... If the concept of the BIOTOPE is to be used to describe common, recognizable Texas Gulf coast communities, then we can use these descriptions to demonstrate the results of changes. For example, if one plans to dredge a grass flat to produce a spoil bank and a channel, the Biotopes of these three areas can be compared to allow the decision maker to evaluate how the change may affect the area involved. Because the decision maker is not always scientifically oriented, we have elected to describe the Biotope by artists' renditions accompanied with lists of common and scientific names of major species of plants and animals and a description of the relative productivity of the major organisms in the area.Supported in part by Coastal Resources Management Program, Office of the Governor, IAC (72-73)-806, and The National Science Foundation RANN, Grant GI-34870XMarine Scienc
Dynamical control of quantum state transfer within hybrid open systems
We analyze quantum state-transfer optimization within hybrid open systems,
from a "noisy" (write-in) qubit to its "quiet" counterpart (storage qubit).
Intriguing interplay is revealed between our ability to avoid bath-induced
errors that profoundly depend on the bath-memory time and the limitations
imposed by leakage out of the operational subspace. Counterintuitively, under
no circumstances is the fastest transfer optimal (for a given transfer energy)
A THEORY OF QUALITATIVE SIMILARITY
The central result of this paper establishes an isomorphism between two types of mathematical structures: ""ternary preorders"" and ""convex topologies."" The former are characterized by reflexivity, symmetry and transitivity conditions, and can be interpreted geometrically as ordered betweenness relations; the latter are defined as intersection-closed families of sets satisfying an ""abstract convexity"" property. A large range of examples is given. As corollaries of the main result we obtain a version of Birkhoff''s representation theorem for finite distributive lattices, and a qualitative version of the representation of ultrametric distances by indexed taxonomic hierarchies.
Applications of remote sensing to estuarine management
Projects for sewage outfall siting for pollution control in the lower Chesapeake Bay wetlands are reported. A dye-buoy/photogrammetry and remote sensing technique was employed to gather circulation data used in outfall siting. This technique is greatly favored over alternate methods because it is inexpensive, produces results quickly, and reveals Lagrangian current paths which are preferred in making siting decisions. Wetlands data were obtained by interpretation of color and color infrared photographic imagery from several altitudes. Historical sequences of photographs are shown that were used to document wetlands changes. Sequential infrared photography of inlet basins was employed to determine tidal prisms, which were input to mathematical models to be used by state agencies in pollution control. A direct and crucial link between remote sensing and management decisions was demonstrated in the various projects
On the number of representations providing noiseless subsystems
This paper studies the combinatoric structure of the set of all
representations, up to equivalence, of a finite-dimensional semisimple Lie
algebra. This has intrinsic interest as a previously unsolved problem in
representation theory, and also has applications to the understanding of
quantum decoherence. We prove that for Hilbert spaces of sufficiently high
dimension, decoherence-free subspaces exist for almost all representations of
the error algebra. For decoherence-free subsystems, we plot the function
which is the fraction of all -dimensional quantum systems which
preserve bits of information through DF subsystems, and note that this
function fits an inverse beta distribution. The mathematical tools which arise
include techniques from classical number theory.Comment: 17 pp, 4 figs, accepted for Physical Review
Discrete symmetries and 1/3-quantum vortices in condensates of F=2 cold atoms
In this Letter we study discrete symmetries of mean field manifolds of
condensates of F=2 cold atoms, and various unconventional quantum vortices.
Discrete quaternion symmetries result in two species of spin defects that can
only appear in integer vortices while {\em cyclic} symmetries are found to
result in a phase shift of (or ) and therefore 1/3- (or 2/3-)
quantum vortices in condensates. We also briefly discuss 1/3-quantum vortices
in condensates of trimers.Comment: 4 pages, 2 figures included; published versio
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