1,273 research outputs found
Evidence for Stellar Streaming in the Cores of Elliptical Galaxies: A Kinematic Signature of Mergers?
We present evidence for non-Gaussian velocity fields within the cores of
luminous elliptical galaxies. This evidence is based upon high signal-to-noise,
medium-resolution spectroscopy of the cores of early-type members of the Virgo
and Coma clusters obtained with the WIYN 3.5-m telescope. The Virgo data were
acquired using an integral-field unit (DensePak) allowing the velocity field to
be sampled over a variety of spatial scales. The Coma data were obtained
through single, 2-arcsec diameter fibers. The cross-correlation profiles of
luminous ellipticals show considerable structure, often having several features
with amplitudes as high as 10% that of the cross-correlation peak itself. This
structure is most obvious within a radius of 1.5 arcsec (at Virgo), or < 100
pc, and is nearly undetectable when the data are binned over R < 15 arcsec, or
< 1 kpc. Similar features are found in the single-fiber spectra of the luminous
ellipticals in the Coma Cluster suggesting they are ubiquitous to giant
ellipticals. Interesting, only the most luminous elliptical galaxies show this
phenomena; the central regions of lower luminosity ellipticals have regular,
Gaussian-like profiles. We interpret this kinematic structure as ``stellar
streaming'' and suggest that this phenomena could be a relic signature of the
merger history of luminous elliptical galaxies.Comment: Latex, 5 pages, 2 figure
Resources in Europe of interest to mathematics teachers,
Thesis (M.A.)--Boston University. This thesis was written in conjunction with Dennis J. Roberts, Mary Lee McLaughlin and Robert F. Pierce.Statement of the problem:
It is the purpose of this thesis to formulate plans for a guided tour throughout Western Europe for secondary-school teachers with emphasis on present and past mathematical and allied science contributions. This study will serve as an answer to four fundamental questions:
1. What are the resources available in Europe of value to mathematics teachers?
2. From the standpoint of marginal utility, which of these would be the most important?
3. where are they to be found?
4. How long would it take to see each of them profitably in a limited amount of time? [TRUNCATED
Site Specific Management: The Pros, the Cons, and the Realities
Site specific management (SSM) for agriculture involves the variable management of soils and crops according to localized conditions within a field. Known by many other names, such as Grid Farming , Farming by Soils or Variable Rate Technology (VRT), SSM is a rapidly emerging set of technologies that allow farmers to manage their soils and crops on-the-go as equipment moves across a field. In essence, SSM is about doing the right thing, at the right time, in the right place, in the right way. Thus, SSM is intuitively appealing because it represents a means of improving the economic and environmental performance of cropping systems. However, while proponents of SSM will endorse its great potential, the fact is that SSM is an emerging technology that is best described as still in its infancy. Thus, at this stage in its development, SSM has its strengths (Pros) and its weaknesses (Cons) which in combination clearly define the current status of SSM for agriculture (Realities). What follows is a brief overview describing some essential elements of SSM and the degree to which these elements have or have not been developed
Applications of TRMM-based Multi-Satellite Precipitation Estimation for Global Runoff Simulation: Prototyping a Global Flood Monitoring System
Advances in flood monitoring/forecasting have been constrained by the difficulty in estimating rainfall continuously over space (catchment-, national-, continental-, or even global-scale areas) and flood-relevant time scale. With the recent availability of satellite rainfall estimates at fine time and space resolution, this paper describes a prototype research framework for global flood monitoring by combining real-time satellite observations with a database of global terrestrial characteristics through a hydrologically relevant modeling scheme. Four major components included in the framework are (1) real-time precipitation input from NASA TRMM-based Multi-satellite Precipitation Analysis (TMPA); (2) a central geospatial database to preprocess the land surface characteristics: water divides, slopes, soils, land use, flow directions, flow accumulation, drainage network etc.; (3) a modified distributed hydrological model to convert rainfall to runoff and route the flow through the stream network in order to predict the timing and severity of the flood wave, and (4) an open-access web interface to quickly disseminate flood alerts for potential decision-making. Retrospective simulations for 1998-2006 demonstrate that the Global Flood Monitor (GFM) system performs consistently at both station and catchment levels. The GFM website (experimental version) has been running at near real-time in an effort to offer a cost-effective solution to the ultimate challenge of building natural disaster early warning systems for the data-sparse regions of the world. The interactive GFM website shows close-up maps of the flood risks overlaid on topography/population or integrated with the Google-Earth visualization tool. One additional capability, which extends forecast lead-time by assimilating QPF into the GFM, also will be implemented in the future
Reproductive Failure in UK Harbour Porpoises Phocoena phocoena : Legacy of Pollutant Exposure?
This research was supported by a Marie Curie International Outgoing Fellowship within the Seventh European Community Framework Programme (Project Cetacean-stressors, PIOF-GA-2010-276145 to PDJ and SM). Additional funding was provided through the Agreement on the Conservation of Small Cetaceans of the Baltic, North East Atlantic, Irish and North Seas (ASCOBANS) (Grants SSFA/2008 and SSFA / ASCOBANS / 2010 / 5 to SM). Analysis of Scottish reproductive and teeth samples was funded by the EC-funded BIOCET project (BIOaccumulation of persistent organic pollutants in small CETaceans in European waters: transport pathways and impact on reproduction, grant EVK3-2000-00027 to GJP), and Marine Scotland (GJP). Samples examined in this research were collected under the collaborative Cetacean Strandings Investigation Programme (http://ukstrandings.org/), which is funded by the Department for Environment, Food and Rural Affairs (Defra) and the UK’s Devolved Administrations in Scotland and Wales (http://sciencesearch.defra.gov.uk/Default.aspx?Menu=Menu&Module=More&Location=None&Completed=0&ProjectID=15331) (grants to PDJ, RD). UK Defra also funded the chemical analysis under a service-level agreement with the Centre for Environment, Fisheries and Aquaculture Science (grants to RJL, JB). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Using native warm-season grass, forb and legume mixtures for biomass, livestock forage and wildlife benefits : a case study (2017)
Case StudyThis guide is a companion to MU Extension publications G9422, Integrating Practices That Benefit Wildlife With Crops Grown for Biomass in Missouri, and G9423, Mixtures of Native Warm-Season Grasses, Forbs and Legumes for Biomass, Forage and Wildlife Habitat, which outlines the benefits of using these mixtures of native warm-season forages and provides information to help landowners make informed decisions on enhancing wildlife habitats while producing crops for biomass. Establishment and management practices, as well as yield results, are presented as a case study in this guide so that others can implement similar practices on their property
Constrained Multistate Sequence Design for Nucleic Acid Reaction Pathway Engineering
We describe a framework for designing the sequences of multiple nucleic acid strands intended to hybridize in solution via a prescribed reaction pathway. Sequence design is formulated as a multistate optimization problem using a set of target test tubes to represent reactant, intermediate, and product states of the system, as well as to model crosstalk between components. Each target test tube contains a set of desired “on-target” complexes, each with a target secondary structure and target concentration, and a set of undesired “off-target” complexes, each with vanishing target concentration. Optimization of the equilibrium ensemble properties of the target test tubes implements both a positive design paradigm, explicitly designing for on-pathway elementary steps, and a negative design paradigm, explicitly designing against off-pathway crosstalk. Sequence design is performed subject to diverse user-specified sequence constraints including composition constraints, complementarity constraints, pattern prevention constraints, and biological constraints. Constrained multistate sequence design facilitates nucleic acid reaction pathway engineering for diverse applications in molecular programming and synthetic biology. Design jobs can be run online via the NUPACK web application
Supreme Court Brief Amicus Curiae of Administrative Law Scholars in Support of Neither Party
This brief on behalf of 29 administrative law scholars takes no position on whether Administrative Law Judges (ALJs) are employees or inferior officers. It urges the Court to issue an opinion that respects the decision that Congress made unanimously in 1946 to enact numerous statutory safeguards that assure that ALJs have decisional independence from the agencies where they work while assuring that agencies retain control over the policy content and legal basis for any decision made in an adjudication in which an ALJ presides.
The brief describes the fifteen years of study and deliberation that led to the unanimous decision of Congress to enact the Administrative Procedure Act (APA) in 1946. It describes the particular attention that Congress devoted to the critical task of providing ALJs with the combination of statutory safeguards that minimize the risk that they will favor the agencies for whom they adjudicate cases while assuring that the agencies retain control of the policy content of any decision made in such an adjudication. It then describes the series of opinions the Supreme Court issued during the 1950s in which the Justices unanimously praised the provisions of the APA that assure that ALJs conduct adjudicatory hearings in an unbiased manner, explained the importance of those statutory provisions in protecting the values reflected in the Due Process Clause, and urged Congress to make those safeguards applicable to all agency adjudications. It concludes by urging the Court to issue an opinion that respects the decision that Congress made in 1946 to insulate ALJs from potential sources of pro-agency bias by including in the APA a combination of provisions that confer decisional independence on ALJs
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REMOVAL OF CHLORIDE FROM ACIDIC SOLUTIONS USING NO2
Chloride (Cl{sup -}) salt processing in strong acids is used to recycle plutonium (Pu) from pyrochemical residues. The Savannah River National Laboratory (SRNL) is studying the potential application of nitrogen dioxide (NO{sub 2}) gas to effectively convert dissolved pyrochemical salt solutions to chloride-free solutions and improve recovery operations. An NO{sub 2} sparge has been shown to effectively remove Cl{sup -} from solutions containing 6-8 M acid (H{sup +}) and up to 5 M Cl{sup -}. Chloride removal occurs as a result of the competition of at least two reactions, one which is acid-dependent. Below 4 M H+, NO2 reacts with Cl- to produce nitrosyl chloride (ClNO). Between 6 M and 8 M H{sup +}, the reaction of hydrochloric acid (HCl) with nitric acid (HNO{sub 3}), facilitated by the presence of NO{sub 2}, strongly affects the rate of Cl{sup -} removal. The effect of heating the acidic Cl{sup -} salt solution without pre-heating the NO{sub 2} gas has minimal effect on Cl{sup -} removal rates when the contact times between NO{sub 2} and the salt solution are on the order of seconds
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CHLORIDE WASHER PERFORMACE TESTING
Testing was performed to determine the chloride (Cl-) removal capabilities of the Savannah River National Laboratory (SRNL) designed and built Cl- washing equipment intended for HB-Line installation. The equipment to be deployed was tested using a cerium oxide (CeO2) based simulant in place of the 3013 plutonium oxide (PuO2) material. Two different simulant mixtures were included in this testing -- one having higher Cl- content than the other. The higher Cl- simulant was based on K-Area Interim Surveillance Inspection Program (KIS) material with Cl- content approximately equal to 70,000 ppm. The lower Cl- level simulant was comparable to KIS material containing approximately 8,000-ppm Cl- content. The performance testing results indicate that the washer is capable of reducing the Cl- content of both surrogates to below 200 ppm with three 1/2-liter washes of 0.1M sodium hydroxide (NaOH) solution. Larger wash volumes were used with similar results - all of the prescribed test parameters consistently reduced the Cl- content of the surrogate to a value below 200 ppm Cl- in the final washed surrogate material. The washer uses a 20-micron filter to retain the surrogate solids. Tests showed that 0.16-0.41% of the insoluble fraction of the starting mass passed through the 20-micron filter. The solids retention performance indicates that the fissile masses passing through the 20-micron filter should not exceed the waste acceptance criteria for discard in grout to TRU waste. It is recommended that additional testing be pursued for further verification and optimization purposes. It is likely that wash volumes smaller than those tested could still reduce the Cl- values to acceptable levels. Along with reduced wash volumes, reuse of the third wash volume (in the next run processed) should be tested as a wash solution minimization plan. A 67% reduction in the number of grouted paint pails could be realized if wash solution minimization testing returned acceptable results
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