11 research outputs found
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Upgraded coal interest group. Quarterly report, July 1, 1995--September 30, 1995
The objectives of the Upgraded Coal Interest Group (UCIG) are as follows: Review and update the status of various coal upgrading technologies and developments and critically assess the results. Perform engineering screening analyses on various coal upgrading approaches. Perform commercialization analyses that will promote the availability and use of upgraded coal products by quantifying the benefits of using them. Identify market opportunities for introduction of upgraded coals. Perform critical analyses on a variety of coals and technologies in areas important to users but not readily available. Perform critical experiments which will show the differences between technologies
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Upgraded Coal Interest Group. Technical progress report, January 1, 1995--March 31, 1995
This report presents information from the coal interest group. Topics of discussion at the meeting included the current political views concerning the Department of Energy and programs contained therein. The group met on January 10 and 11, in Nashville, TN. The status of various coal upgrading technologies was also reviewed. Four new technology opportunities were given reviews, Coal/Waste pellets, Custom Coals advanced technology, CSRC sulfur removing bacteria and a Mag-Mill which is a magnetic separation done within the pulverizer. Coal Waste pellets is a technology for making pellets of coal and fiber waste from recycling plants. The incentives are low cost and low sulfur and nitrogen. Lebowitz made a field trip to the pilot unit in Canton Ohio. The Mag Mill takes advantage of the natural concentration of pyrite in the pulverizer recycle stream (due to its hardness). Special magnets are installed in the mill to remove pyrite from this stream. Custom Coals reported on an advanced two step process for removal of organic sulfur from coal. Consolidated Sulfur Reduction Co. reported on a two step microbial desulfurization process
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Upgraded coal interest group. First quarterly technical progress report, October 1, 1994--December 31, 1994
The interest group got under way effective January 1, 1994, with nine utility members, EPRI, Bechtel, and the Illinois Clean Coal Institute. DOE participation was effective October 1, 1994. The first meeting was held on April 22, 1994 in Springfield, Illinois and the second meeting was held on August 10--11, 1994 at Johnstown, Pennsylvania. Technical reviews were prepared in several areas, including the following: status of low rank coal upgrading, advanced physical coal cleaning, organic sulfur removal from coal, handling of fine coal, combustion of coal water slurries. It was concluded that, for bituminous coals, processing of fines from coal cleaning plants or impoundments was going to be less costly than processing of coal, since the fines were intrinsically worth less and advanced upgrading technologies require fine coal. Penelec reported on benefits of NOX reductions when burning slurry fuels. Project work was authorized in the following areas: Availability of fines (CQ, Inc.), Engineering evaluations (Bechtel), and Evaluation of slurry formulation and combustion demonstrations (EER/MATS). The first project was completed
Respiratory symptoms and lung function effects of domestic exposure to tobacco smoke and cooking by gas in non-smoking women in Singapore.
The Po River Delta (North Italy) Indoor Epidemiological Study: Home Characteristics, Indoor Pollutants, and Subjects' Daily Activity Pattern
Dynamics of oscillator chains
The Fermi\u2013Pasta\u2013Ulam (FPU) nonlinear oscillator chain has proved to be a seminal system for investigating problems in nonlinear dynamics. First proposed as a nonlinear system to elucidate the foundations of statistical mechanics, the initial lack of confirmation of the researchers expectations eventually led to a number of profound insights into the behavior of high-dimensional nonlinear systems. The initial numerical studies, proposed to demonstrate that energy placed in a single mode of the linearized chain would approach equipartition through nonlinear interactions, surprisingly showed recurrences. Although subsequent work showed that the origin of the recurrences is nonlinear resonance, the question of lack of equipartition remained. The attempt to understand the regularity bore fruit in a profound development in nonlinear dynamics: the birth of soliton theory. A parallel development, related to numerical observations that, at higher energies, equipartition among modes could be approached, was the understanding that the transition with increasing energy is due to resonance overlap. Further numerical investigations showed that time-scales were also important, with a transition between faster and slower evolution. This was explained in terms of mode overlap at higher energy and resonance overlap at lower energy. Numerical limitations to observing a very slow approach to equipartition and the problem of connecting high-dimensional Hamiltonian systems to lower dimensional studies of Arnold diffusion, which indicate transitions from exponentially slow diffusion along resonances to power-law diffusion across resonances, have been considered. Most of the work, both numerical and theoretical, started from low frequency (long wavelength) initial conditions.
Coincident with developments to understand equipartition was another program to connect a statistical phenomenon to nonlinear dynamics, that of understanding classical heat conduction. The numerical studies were quite different, involving the excitation of a boundary oscillator with chaotic motion, rather than the excitation of the entire chain with regular motion. Although energy transitions are still important, the inability to reproduce exactly the law of classical heat conduction led to concern for the generiticity of the FPU chain and exploration of other force laws. Important concepts of unequal masses, and \u201canti-integrability,\u201d i.e. isolation of some oscillators, were considered, as well as separated optical and acoustic modes that could only communicate through very weak interactions. The importance of chains that do not allow nonlinear wave propagation in producing the Fourier heat conduction law is now recognized.
A more recent development has been the exploration of energy placed on the FPU or related oscillator chains in high-frequency (short wavelength) modes and the existence of isolated structures (breathers). Breathers are found as solutions to partial differential equations, analogous to solitons at lower frequency. On oscillator chains, such as the FPU, energy initially in a single high-frequency mode is found, at higher energies, to self-organize in oscillator space to form compact structures. These structures are \u201cchaotic breathers,\u201d i.e. not completely stable, and disintegrate on longer time-scales. With the significant progress in understanding this evolution, we now have a rather complete picture of the nonlinear dynamics of the FPU and related oscillator chains, and their relation to a wide range of concepts in nonlinear dynamics.
This chapter\u2019s purpose is to explicate these many concepts. After a historical perspective the basic chaos theory background is reviewed. Types of oscillators, numerical methods, and some analytical results are considered. Numerical results of studies of equipartition, both from low-frequency and high-frequency modes, are presented, together with numerical studies of heat conduction. These numerical studies are related to analytical calculations and estimates of energy transitions and time-scales to equipartition