586 research outputs found
Intangible Capital and Economic Growth
Published macroeconomic data traditionally exclude most intangible investment from measured GDP. This situation is beginning to change, but our estimates suggest that as much as 3 trillion of business intangible capital stock. To assess the importance of this omission, we add capital to the standard sources-of-growth framework used by the BLS, and find that the inclusion of our list of intangible assets makes a significant difference in the observed patterns of U.S. economic growth. The rate of change of output per worker increases more rapidly when intangibles are counted as capital, and capital deepening becomes the unambiguously dominant source of growth in labor productivity. The role of multifactor productivity is correspondingly diminished, and labor's income share is found to have decreased significantly over the last 50 years.
Numerical simulation of gas-phase detonation transmission
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77137/1/AIAA-1991-579-313.pd
Effect of the boundary layer upon the flow in a conical hypersonic nozzle
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76641/1/AIAA-2269-288.pd
Detonability of RDX dust in air/oxygen mixtures
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77369/1/AIAA-9528-470.pd
Mechanisms of detonation transmission in layered H 2 -O 2 mixtures
When a plane detonation propagating through an explosive comes into contact with a bounding explosive, different types of diffraction patterns, which may result in the transmission of a detonation into the bounding mixture, are observed. The nature of these diffraction patterns and the mode of detonation transmission depend on the properties of the primary and bounding explosives. An experimental and analytical study of such diffractions, which are fundamental to many explosive applications, has been conducted in a two channel shock tube, using H 2 -O 2 mixtures of different equivalence ratios as the primary and bounding or secondary explosive. The combination of mixtures was varied from rich primary / lean secondary to lean primary / rich secondary since the nature of the diffraction was found to depend on whether the Chapman-Jouguet velocity of the primary mixture, D p , was greater than or less than that of the secondary mixture, D s . Schlieren framing photographs of the different diffraction patterns were obtained and used to measure shock and oblique detonation wave angles and velocities for the different diffraction patterns, and these were compared with the results of a steady-state shock-polar solution of the diffraction problem. Two basic types of diffraction and modes of detonation reinitiation were observed. When D p > D s , an oblique shock connecting the primary detonation to an oblique detonation in the secondary mixture was observed. With D p D s . When D p > D s , the primary wave acts like a wedge moving into the secondary mixture with velocity D p after steady state has been reached, a configuration which also arises in oblique-detonation ramjets and hypervelocity drivers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46110/1/193_2005_Article_BF01419004.pd
Nonlinear DC-response in Composites: a Percolative Study
The DC-response, namely the - and - charateristics, of a variety
of composite materials are in general found to be nonlinear. We attempt to
understand the generic nature of the response charactersistics and study the
peculiarities associated with them. Our approach is based on a simple and
minimal model bond percolative network. We do simulate the resistor network
with appropritate linear and nonlinear bonds and obtain macroscopic nonlinear
response characteristics. We discuss the associated physics. An effective
medium approximation (EMA) of the corresponding resistor network is also given.Comment: Text written in RevTEX, 15 pages (20 postscript figures included),
submitted to Phys. Rev. E. Some minor corrections made in the text, corrected
one reference, the format changed (from 32 pages preprint to 15 pages
Numerical simulation of detonation reignition in H-O mixtures in area expansions
Time-dependent, two-dimensional, numerical simulations of a transmitted detonation show reignition occuring by one of two mechanisms. The first mechanism involves the collision of triple points as they expand along a decaying shock front. In the second mechanism ignition results from the coalescence of a number of small, relatively high pressure regions left over from the decay of weakened transverse waves. The simulations were performed using an improved chemical kinetic model for stoichiometric H -O mixtures. The initial conditions were a propagating, two-dimensional detonation resolved enough to show transverse wave structure. The calculations provide clarification of the reignition mechanism seen in previous H -O -Ar simulations, and again demonstrate that the transverse wave structure of the detonation front is critical to the reignition process.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41914/1/193-10-1-33_00100033.pd
Eliminating Ditransitives
Abstract. We discuss how higher arity verbs such as give or promise can be treated in an algebraic framework that admits only unary and binary relations and does not rely on event variables
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