84,023 research outputs found
Stratification in steelmaking ladles
The problem of temperature stratification in a steelmaking ladle is considered. There are three distinct zones in the flow, the wall boundary layer, the bottom stagnation zone and the central plug flow. Typical length, velocity and time scales are determined for the flow and compared to numerical simulations. A model of the wall boundary layer using similarity solution techniques is detailed. Models for the temperature stratification in the bottom stagnation zone and the plug flow are included. Recommendations for reducing the temperature stratification in the ladle and improvements to their numerical simulation are made
Venting vapor apparatus Patent
Fuel tank pressure-relief device for venting cryogenic liquid vapors through tubes with porous plu
A Survey of Hypersonic-Ramjet Concepts
A brief discussion is presented of the major problem areas involved in the development of a hypersonic ramjet engine. Keeping the structural temperature to an acceptably low level is the severest problem expected. A rapid survey is made of some of the relatively unconventional concepts that may find application in the hypersonic region. These include supersonic combustors, underwing burning, atmospheric-recombination, engine installation, nuclear power, variable geometry, and fuel-rich operation
Reduction behaviour in Fastmet(TM) pellets
Fastmet (TM), a process developed by the Midrex Corporation, produces iron for steelmaking by heating pellets composed of iron oxide and coal. Here we develop several simple models of the reduction process and confirm claims made by the manufacturer about the conversion time. These models can also be used to investigate the dependence of the conversion time on controlling parameters
QCD in neutron stars and strange stars
This paper provides an overview of the possible role of Quantum Chromo
Dynamics (QDC) for neutron stars and strange stars. The fundamental degrees of
freedom of QCD are quarks, which may exist as unconfined (color
superconducting) particles in the cores of neutron stars. There is also the
theoretical possibility that a significantly large number of up, down, and
strange quarks may settle down in a new state of matter known as strange quark
matter, which, by hypothesis, could be more stable than atomic nuclei. In the
latter case new classes of self-bound, color superconducting objects, ranging
from strange quark nuggets to strange quark stars, should exist. The properties
of such objects will be reviewed along with the possible existence of
deconfined quarks in neutron stars. Implications for observational astrophysics
are pointed out.Comment: 7 pages, 2 figures; presented at the T(R)OPICAL QCD Workshop,
September 26 - October 2, 2010, Cairns, Australi
Aeropropulsion in year 2000
A sampling of probable future engine types, such as convertible engines for helicopters, turboprops for fuel-conservative airliners, and variable-cycle engines for supersonic transports are presented. Related technology improvements in propellers, materials, noise suppression, etc. are reviewed
The NASA research program on propulsion for supersonic cruise aircraft
The objectives and status of the propulsion portion of a program aimed at advancing the technology and establishing a data base appropriate for the possible future development of supersonic cruise aircraft are reviewed. Research related to exhaust nozzles, combustors, and inlets that is covered by the noise, pollution, and dynamics programs is described
The Valuation of Contaminated Land
This paper presents a Monte Carlo based method for explicitly accounting for uncertainty in the valuation of contaminated property. Environmental risk is being quantified by the scientific methods described in this paper. Financial risk is also quantifiable by these techniques. A 1993 Supreme Court case known as Daubert has changed the admission requirements for scientific evidence by expert witnesses. Hoyt (1997) notes that it is "imperative that real estate appraisers who testify be sure that their scientific evidence will stand up to the scrutiny of Daubert of their testimony may be rejected." A scientific method of quantifying the unique financial risk of this type of asset is used for the valuation of contaminated land.
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