457 research outputs found
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
An improvement of the Berry--Esseen inequality with applications to Poisson and mixed Poisson random sums
By a modification of the method that was applied in (Korolev and Shevtsova,
2009), here the inequalities
and
are proved for the
uniform distance between the standard normal distribution
function and the distribution function of the normalized sum of an
arbitrary number of independent identically distributed random
variables with zero mean, unit variance and finite third absolute moment
. The first of these inequalities sharpens the best known version of
the classical Berry--Esseen inequality since
by virtue of
the condition , and 0.4785 is the best known upper estimate of the
absolute constant in the classical Berry--Esseen inequality. The second
inequality is applied to lowering the upper estimate of the absolute constant
in the analog of the Berry--Esseen inequality for Poisson random sums to 0.3051
which is strictly less than the least possible value of the absolute constant
in the classical Berry--Esseen inequality. As a corollary, the estimates of the
rate of convergence in limit theorems for compound mixed Poisson distributions
are refined.Comment: 33 page
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
The shock wave ignition of dusts
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76582/1/AIAA-9095-997.pd
The Electrical-Thermal Switching in Carbon Black-Polymer Composites as a Local Effect
Following the lack of microscopic information about the intriguing well-known
electrical-thermal switching mechanism in Carbon Black-Polymer composites, we
applied atomic force microscopy in order to reveal the local nature of the
process and correlated it with the characteristics of the widely used
commercial switches. We conclude that the switching events take place in
critical interparticle tunneling junctions that carry most of the current. The
macroscopic switched state is then a result of a dynamic-stationary state of
fast switching and slow reconnection of the corresponding junctions.Comment: 14 pages, 5 figures,Typographic correctio
Scapegoat: John Dewey and the character education crisis
Many conservatives, including some conservative scholars, blame the ideas and influence of John Dewey for what has frequently been called a crisis of character, a catastrophic decline in moral behavior in the schools and society of North America. Dewey’s critics claim that he is responsible for the undermining of the kinds of instruction that could lead to the development of character and the strengthening of the will, and that his educational philosophy and example exert a ubiquitous and disastrous influence on students’ conceptions of moral behavior. This article sets forth the views of some of these critics and juxtaposes them with what Dewey actually believed and wrote regarding character education. The juxtaposition demonstrates that Dewey neither called for nor exemplified the kinds of character-eroding pedagogy his critics accuse him of championing; in addition, this paper highlights the ways in which Dewey argued consistently and convincingly that the pedagogical approaches advocated by his critics are the real culprits in the decline of character and moral education
Piezoresistivity and conductance anisotropy of tunneling-percolating systems
Percolating networks based on interparticle tunneling conduction are shown to
yield a logarithmic divergent piezoresistive response close to the critical
point as long as the electrical conductivity becomes nonuniversal. At the same
time, the piezoresistivity or, equivalently, the conductivity anisotropy
exponent remains universal also when the conductive exponent is not,
suggesting a purely geometric origin of . We discuss our results in
relation to the nature of transport for a variety of materials such as
carbon-black--polymer composites and RuO_2-glass systems which show
nonuniversal transport properties and coexistence between tunneling and
percolating behaviors.Comment: 6 pages, 3 figures, Added discussion on experiment
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