62 research outputs found
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Task 2.3 - Review and Assessment of Results from the Comprehensive Characterization of Toxic Emissions from Coal-Fired Power Plants: Semi-annual report, July 1-December 31, 1996.
The air toxic emission data from Phase I were summarized and evaluated in the final Phase I summary report, published in September 1996 and available for distribution in October 1996. Data from Phase I were presented at the Center for Air Toxic Metals annual review meeting at the Energy {ampersand} Environmental Research Center in October 1996. The objective of the project was to provide. an independent review of the Phase I data, evaluate the scientific validity of the conclusions, identify significant correlations between emissions and fuel or process parameters, compare the data with available data from EPRI studies, make recommendations for future studies, and complete a combined report that summarizes Phase I, Phase II, and EPRI findings
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Catalytic fabric filtration for simultaneous NO{sub x} and particulate control. Final report
The overall objective of the project proposed was to evaluate the catalyst-coated fabric filter concept for effective control of NO{sub 2} and particulate emissions simultaneously. General goals included demonstrating high removal efficiency of NO{sub x} and particulate matter, acceptable bag and catalyst life, and that process economics show a significant cost savings in comparison to a commercial SCR process and conventional particulate control. Specific goals included the following: reduce NO{sub x} emissions to 60 ppM or less; demonstrate particulate removal efficiency of >99.5%; demonstrate a bag/catalyst life of >1 year; Control ammonia slip to <25 ppM; show that catalytic fabric filtration can achieve a 50% cost savings over conventional fabric filtration and SCR control technology; determine compatibility with S0{sub 2} removal systems; and show that the concept results in a nonhazardous waste product
Asteroseismology of red giants & galactic archaeology
Red-giant stars are low- to intermediate-mass (~M)
stars that have exhausted hydrogen in the core. These extended, cool and hence
red stars are key targets for stellar evolution studies as well as galactic
studies for several reasons: a) many stars go through a red-giant phase; b) red
giants are intrinsically bright; c) large stellar internal structure changes as
well as changes in surface chemical abundances take place over relatively short
time; d) red-giant stars exhibit global intrinsic oscillations. Due to their
large number and intrinsic brightness it is possible to observe many of these
stars up to large distances. Furthermore, the global intrinsic oscillations
provide a means to discern red-giant stars in the pre-helium core burning from
the ones in the helium core burning phase and provide an estimate of stellar
ages, a key ingredient for galactic studies. In this lecture I will first
discuss some physical phenomena that play a role in red-giant stars and several
phases of red-giant evolution. Then, I will provide some details about
asteroseismology -- the study of the internal structure of stars through their
intrinsic oscillations -- of red-giant stars. I will conclude by discussing
galactic archaeology -- the study of the formation and evolution of the Milky
Way by reconstructing its past from its current constituents -- and the role
red-giant stars can play in that.Comment: Lecture presented at the IVth Azores International Advanced School in
Space Sciences on "Asteroseismology and Exoplanets: Listening to the Stars
and Searching for New Worlds" (arXiv:1709.00645), which took place in Horta,
Azores Islands, Portugal in July 201
dS-Holographic C-Functions with a Topological, Dilatonic Twist
Recently, the holographic aspects of asymptotically de Sitter spacetimes have
generated substantial literary interest. The plot continues in this paper, as
we investigate a certain class of dilatonically deformed ``topological'' de
Sitter solutions (which were introduced in hep-th/0110234). Although such
solutions possess a detrimental cosmological singularity, their interpretation
from a holographic perspective remains somewhat unclear. The current focus is
on the associated generalized -functions, which are shown to maintain their
usual monotonicity properties in spite of this exotic framework. These findings
suggest that such topological solutions may still play a role in our
understanding of quantum gravity with a positive cosmological constant.Comment: Latex, 30 pages; reference added and minor changes to tex
Dwelling on de Sitter
A careful reduction of the three-dimensional gravity to the Liouville
description is performed, where all gauge fixing and on-shell conditions come
from the definition of asymptotic de Sitter spaces. The roles of both past and
future infinities are discussed and the conditions space-time evolution imposes
on both Liouville fields are explicited. Space-times which correspond to
non-equivalent profiles of the Liouville field at past and future infinities
are shown to exist. The qualitative implications of this for any tentative dual
theory are presented.Comment: RevTeX 4, 8 pages, v3: Small clarifications on sections III and IV
and references added/corrected, v4: typo
Automated Structure Solution with the PHENIX Suite
Significant time and effort are often required to solve and complete a macromolecular crystal structure. The development of automated computational methods for the analysis, solution and completion of crystallographic structures has the potential to produce minimally biased models in a short time without the need for manual intervention. The PHENIX software suite is a highly automated system for macromolecular structure determination that can rapidly arrive at an initial partial model of a structure without significant human intervention, given moderate resolution and good quality data. This achievement has been made possible by the development of new algorithms for structure determination, maximum-likelihood molecular replacement (PHASER), heavy-atom search (HySS), template and pattern-based automated model-building (RESOLVE, TEXTAL), automated macromolecular refinement (phenix.refine), and iterative model-building, density modification and refinement that can operate at moderate resolution (RESOLVE, AutoBuild). These algorithms are based on a highly integrated and comprehensive set of crystallographic libraries that have been built and made available to the community. The algorithms are tightly linked and made easily accessible to users through the PHENIX Wizards and the PHENIX GUI
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Task 2.8 -- Mercury speciation and capture in scrubber solutions. Semi-annual report, July 1--December 31, 1996
Investigations into mercury control across conventional scrubber systems have precipitated questions concerning (1) the initial speciation between oxidized and elemental forms of mercury in flue gas from coal-fired boilers and, subsequently, (2) the effects of scrubber slurry composition and pH on the mercury forms. Mercury capture in scrubber slurry is highly dependent on its form. Oxidized mercury is highly water-soluble and can be removed by scrubber slurry, whereas elemental mercury is not and passes through the scrubber to the stack. The objectives of this project are to determine whether scrubber solutions convert either form of mercury to another and whether mercury capture is affected by pH
Stability and Variation in Cadence Formulas in Oral and Semi-Oral Chant Traditions – a Computational Approach
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