35,399 research outputs found
An evaluation: The potential of discarded tires as a source of fuel
The destructive distillation of rubber tire samples was studied by thermogravimetry, differential scanning calorimetry, combustion calorimetry, and mass spectroscopy. The decomposition reaction was found to be exothermic and produced a mass loss of 65 percent. The gas evolution curves that were obtained indicate that a variety of organic materials are evolved simultaneously during the decomposition of the rubber polymer
Classical Sphaleron Rate on Fine Lattices
We measure the sphaleron rate for hot, classical Yang-Mills theory on the
lattice, in order to study its dependence on lattice spacing. By using a
topological definition of Chern-Simons number and going to extremely fine
lattices (up to beta=32, or lattice spacing a = 1 / (8 g^2 T)) we demonstrate
nontrivial scaling. The topological susceptibility, converted to physical
units, falls with lattice spacing on fine lattices in a way which is consistent
with linear dependence on (the Arnold-Son-Yaffe scaling relation) and
strongly disfavors a nonzero continuum limit. We also explain some unusual
behavior of the rate in small volumes, reported by Ambjorn and Krasnitz.Comment: 14 pages, includes 5 figure
Design Criteria for Zero Leakage Connectors for Launch Vehicles. Mathematical Model of Interface Sealing Phenomenon, Volume 2 Final Report
Mathematical model of interface sealing phenomenon in determining design criteria for zero leakage connectors for launch vehicle
Generating entangled atom-photon pairs from Bose-Einstein condensates
We propose using spontaneous Raman scattering from an optically driven
Bose-Einstein condensate as a source of atom-photon pairs whose internal states
are maximally entangled. Generating entanglement between a particle which is
easily transmitted (the photon) and one which is easily trapped and coherently
manipulated (an ultracold atom) will prove useful for a variety of
quantum-information related applications. We analyze the type of entangled
states generated by spontaneous Raman scattering and construct a geometry which
results in maximum entanglement
Transfer or Redemption for a Withdrawing Partner: An Indifference Econometric Decision Model Built on the Position Improvement Equilibrium ( PIE ) Concept
The preferred way for a withdrawing partner to leave a partnership is normally thought to be by way of redemption under Internal Revenue Code Section 736 rather than as a transfer under Section 741 The advantage to the continuing partnership lies in the deductability of the payment to the withdrawing partner for goodwill. The withdrawing partner benefits from a higher exchange price, increased by the tax benefits of redemption treatment. However, the following three factors tilt the preference back toward a 741 transfer for both parties: individual obligation of portions of the exchange price, with additional basis, goodwill negotiations and safeguarding of the optional basis adjustment. To allow for proper consideration of these factors, indifference equations are proposed which produce an exchange price that makes 741 as advantageous to the dominant party as 736. These equations constitute a dynamic interactive econometric model for finding a position improvement equilibrium ( PIE ) indifference model that provides an incisive decision tool. This model takes graduated tax brackets into consideration, heightening its value as a decision tool
Coherent phonon scattering effects on thermal transport in thin semiconductor nanowires
The thermal conductance by phonons of a quasi-one-dimensional solid with
isotope or defect scattering is studied using the Landauer formalism for
thermal transport. The conductance shows a crossover from localized to Ohmic
behavior, just as for electrons, but the nature of this crossover is modified
by delocalization of phonons at low frequency. A scalable numerical
transfer-matrix technique is developed and applied to model
quasi-one-dimensional systems in order to confirm simple analytic predictions.
We argue that existing thermal conductivity data on semiconductor nanowires,
showing an unexpected linear dependence, can be understood through a model that
combines incoherent surface scattering for short-wavelength phonons with nearly
ballistic long-wavelength phonons. It is also found that even when strong
phonon localization effects would be observed if defects are distributed
throughout the wire, localization effects are much weaker when defects are
localized at the boundary, as in current experiments.Comment: 13 page
Entanglement between photons and atoms coupled out from a Bose-Einstein-Condensate
We study the limitations to the relative number squeezing between photons and
atoms coupled out from a homogeneous Bose-Einstein-Condensate. We consider the
coupling between the translational atomic states by two photon Bragg processes,
with one of the photon modes involved in the Bragg process in a coherent state,
and the other initially unpopulated. We start with an interacting Bose-
condensate at zero temperature and compute the time evolution for the system.
We study the squeezing, i.e. the variance of the occupation number difference
between the second photon and the atomic c.m. mode. We discuss how collisions
between the atoms and photon rescattering affect the degree of squeezing which
may be reached in such experiments.Comment: 4 pages RevTeX, 3 figure
- …