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1

Enriching the Web Processing Service  

NASA Astrophysics Data System (ADS)

The OGC Web Processing Service (WPS) provides a standard for implementing geospatial processes in service-oriented networks. In its current version 1.0.0 it allocates the operations GetCapabilities, DescribeProcess and Execute, which can be used to offer custom processes based on single or multiple sub-processes. A large range of ready to use fine granular, fundamental geospatial processes have been developed by the GIS-community in the past. However, modern use cases or whole workflow processes demand specifications of lifecycle management and service orchestration. Orchestrating smaller sub-processes is a task towards interoperability; a comprehensive documentation by using appropriate metadata is also required. Though different approaches were tested in the past, developing complex WPS applications still requires programming skills, knowledge about software libraries in use and a lot of effort for integration. Our toolset RichWPS aims at providing a better overall experience by setting up two major components. The RichWPS ModelBuilder enables the graphics-aided design of workflow processes based on existing local and distributed processes and geospatial services. Once tested by the RichWPS Server, a composition can be deployed for production use on the RichWPS Server. The ModelBuilder obtains necessary processes and services from a directory service, the RichWPS semantic proxy. It manages the lifecycle and is able to visualize results and debugging-information. One aim will be to generate reproducible results; the workflow should be documented by metadata that can be integrated in Spatial Data Infrastructures. The RichWPS Server provides a set of interfaces to the ModelBuilder for, among others, testing composed workflow sequences, estimating their performance and to publish them as common processes. Therefore the server is oriented towards the upcoming WPS 2.0 standard and its ability to transactionally deploy and undeploy processes making use of a WPS-T interface. In order to deal with the results of these processing workflows, a server side extension enables the RichWPS Server and its clients to use WPS presentation directives (WPS-PD), a content related enhancement for the standardized WPS schema. We identified essential requirements of the components of our toolset by applying two use cases. The first enables the simplified comparison of modeled and measured data, a common task in hydro-engineering to validate the accuracy of a model. An implementation of the workflow includes reading, harmonizing and comparing two datasets in NetCDF-format. 2D Water level data from the German Bight can be chosen, presented and evaluated in a web client with interactive plots. The second use case is motivated by the Marine Strategy Directive (MSD) of the EU, which demands monitoring, action plans and at least an evaluation of the ecological situation in marine environment. Information technics adapted to those of INSPIRE should be used. One of the parameters monitored and evaluated for MSD is the expansion and quality of seagrass fields. With the view towards other evaluation parameters we decompose the complex process of evaluation of seagrass in reusable process steps and implement those packages as configurable WPS.

Wosniok, Christoph; Bensmann, Felix; Wössner, Roman; Kohlus, Jörn; Roosmann, Rainer; Heidmann, Carsten; Lehfeldt, Rainer

2014-05-01

2

Novel Membranes and Processes for Oxygen Enrichment  

SciTech Connect

The overall goal of this project is to develop a membrane process that produces air containing 25-35% oxygen, at a cost of $25-40/ton of equivalent pure oxygen (EPO2). Oxygen-enriched air at such a low cost will allow existing air-fueled furnaces to be converted economically to oxygen-enriched furnaces, which in turn will improve the economic and energy efficiency of combustion processes significantly, and reduce the cost of CO{sub 2} capture and sequestration from flue gases throughout the U.S. manufacturing industries. During the 12-month Concept Definition project: We identified a series of perfluoropolymers (PFPs) with promising oxygen/nitrogen separation properties, which were successfully made into thin film composite membranes. The membranes showed oxygen permeance as high as 1,200 gpu and oxygen/nitrogen selectivity of 3.0, and the permeance and selectivity were stable over the time period tested (60 days). We successfully scaled up the production of high-flux PFP-based membranes, using MTR's commercial coaters. Two bench-scale spiral-wound modules with countercurrent designs were made and parametric tests were performed to understand the effect of feed flow rate and pressure, permeate pressure and sweep flow rate on the membrane module separation properties. At various operating conditions that modeled potential industrial operating conditions, the module separation properties were similar to the pure-gas separation properties in the membrane stamps. We also identified and synthesized new polymers [including polymers of intrinsic microporosity (PIMs) and polyimides] with higher oxygen/nitrogen selectivity (3.5-5.0) than the PFPs, and made these polymers into thin film composite membranes. However, these membranes were susceptible to severe aging; pure-gas permeance decreased nearly six-fold within two weeks, making them impractical for industrial applications of oxygen enrichment. We tested the effect of oxygen-enriched air on NO{sub x} emissions using a Bloom baffle burner at GTI. The results are positive and confirm that oxygen-enriched combustion can be carried out without producing higher levels of NOx than normal air firing, if lancing of combustion air is used and the excess air levels are controlled. A simple economic study shows that the membrane processes can produce O{sub 2} at less than $40/ton EPO{sub 2} and an energy cost of 1.1-1.5 MMBtu/ton EPO{sub 2}, which are very favorable compared with conventional technologies such as cryogenics and vacuum pressure swing adsorption processes. The benefits of integrated membrane processes/combustion process trains have been evaluated, and show good savings in process costs and energy consumption, as well as reduced CO{sub 2} emissions. For example, if air containing 30% oxygen is used in natural gas furnaces, the net natural gas savings are an estimated 18% at a burner temperature of 2,500 F, and 32% at a burner temperature of 3,000 F. With a 20% market penetration of membrane-based oxygen-enriched combustion in all combustion processes by 2020, the energy savings would be 414-736 TBtu/y in the U.S. The comparable net cost savings are estimated at $1.2-2.1 billion per year by 2020, calculated as the value of fuel savings subtracted from the cost of oxygen production. The fuel savings of 18%-32% by the membrane/oxygen-enriched combustion corresponds to an 18%-32% reduction in CO{sub 2} emissions, or 23-40 MM ton/y less CO{sub 2} from natural gas-fired furnaces by 2020. In summary, results from this project (Concept Definition phase) are highly promising and clearly demonstrate that membrane processes can produce oxygen-enriched air in a low cost manner that will lower operating costs and energy consumption in industrial combustion processes. Future work will focus on proof-of-concept bench-scale demonstration in the laboratory.

Lin, Haiqing

2011-11-15

3

Optimization criteria and biological process enrichment in homologous multiprotein modules  

PubMed Central

Biological process enrichment is a widely used metric for evaluating the quality of multiprotein modules. In this study, we examine possible optimization criteria for detecting homologous multiprotein modules and quantify their effects on biological process enrichment. We find that modularity, linear density, and module size are the most important criteria considered, complementary to each other, and that graph theoretical attributes account for 36% of the variance in biological process enrichment. Variations in protein interaction similarity within module pairs have only minor effects on biological process enrichment. As random modules increase in size, both biological process enrichment and modularity tend to improve, although modularity does not show this upward trend in modules with size at most 50 proteins. To adjust for these trends, we recommend a size correction based on random sampling of modules when using biological process enrichment or other attributes to evaluate module boundaries. Characteristics of homologous multiprotein modules optimized for each of the optimization criteria are examined. PMID:23757502

Hodgkinson, Luqman; Karp, Richard M.

2013-01-01

4

Metal enrichment processes in the marine environment  

SciTech Connect

This study discusses metal enrichment in oceanic sediments resulting from remobilization, scavenging, pollution and hydrothermal inputs in the Mississippi River-Gulf of Mexico and Mid-Atlantic Ridge at 26/sup 0/N. Suspended particles collected from the Mississippi River during mean water and suspended-sediment discharge have metal concentrations which vary by <5% for Al, Cd, Cu, Fe, Pb, and Zn and approx.10% for Mn. The massive sediment load carried by the Mississippi River is rapidly deposited on the Mississippi Delta in the Gulf of Mexico. Aluminum and Fe concentrations in Mississippi Delta sediments are similar to those of average Mississippi River suspended matter throughout the delta. In contrast, the Cu/Al ratio in surficial sediments (0-1 cm) decreases from 4.1 x 10/sup -4/ for average suspended matter to 2.7 x 10/sup -4/ about 45 km from the mouth of Southwest Pass. Copper lost from delta sediments can be traced to the deep Gulf of Mexico where concentrations average 50-70 ..mu..g g/sup -1/ compared with 33 ..mu..g g/sup -1/ for Mississippi River suspended matter. The observed increase in offshore sediments in linked to scavenging of Cu by particles. A similar scenario can be presented for Mn.

Metz, S.

1986-01-01

5

Interstellar Processes Leading to Molecular Deuterium Enrichment and Their Detection  

NASA Technical Reports Server (NTRS)

Large deuterium (D) enrichments in meteoritic materials indicate that interstellar organic materials survived incorporation into parent bodies within the forming Solar System. These enrichments are likelier due to one or more of four distinct astrochemical processes. These are (1) low temperature gas phase ion-molecule reactions; (2) low temperature gas-grain reactions; (3) gas phase unimolecular photodissociation, and (4) ultraviolet photolysis in D-enriched ice mantles. Each of these processes should be associated with molecular carriers having, distinct regiochemical signatures (D placement on the product molecules, correlation with specific chemical functionalities, etc.). These processes are reviewed and specific spectroscopic signatures for the detection of these processes in space are identified and described.

Sandford, Scott A.; Kliss, Mark (Technical Monitor)

2001-01-01

6

Enriching Business Process Models with Decision Rules  

E-print Network

) quantity n Fig. 1. Make-or-Buy Process In management science, decision theory deals with the identification decisions in time is one of the key tasks in every business. In this context, decision theory fosters decision-making based on well-defined decision rules. The latter evaluate a given set of input parameters

Ulm, Universität

7

Process of [sup 196]Hg enrichment  

DOEpatents

A simple rate equation model shows that by increasing the length of the photochemical reactor and/or by increasing the photon intensity in said reactor, the feedstock utilization of [sup 196]Hg will be increased. Two preferred embodiments of the present invention are described, namely (1) long reactors using long photochemical lamps and vapor filters; and (2) quartz reactors with external UV reflecting films. These embodiments have each been constructed and operated, demonstrating the enhanced utilization process dictated by the mathematical model (also provided).

Grossman, M.W.; Mellor, C.E.

1993-04-27

8

Traits de personnalit computationnels Enrichissement de la taxonomie FFM/NEO PI-R avec  

E-print Network

Traits de personnalité computationnels Enrichissement de la taxonomie FFM/NEO PI-R avec des gloses taxonomie NEO PI-R, en relation avec le Modèle des Cinq Facteurs (FFM ­ Five Factor Model). Le processus de dans les positions de l'arborescence définies par la taxonomie FFM/NEO PI-R, une phase de réarrangement

Sansonnet, Jean-Paul

9

Process for preparing a chemical compound enriched in isotope content. [nitrogen 15-enriched nitric acid  

DOEpatents

A process to prepare a chemical enriched in isotope content includes: a chemical exchange reaction between a first and second compound which yields an isotopically enriched first compound and an isotopically depleted second compound; the removal of a portion of the first compound as product and the removal of a portion of the second compound as spent material; the conversion of the remainder of the first compound to the second compound for reflux at the product end of the chemical exchange reaction region; the conversion of the remainder of the second compound to the first compound for reflux at the spent material end of the chemical exchange region; and the cycling of the additional chemicals produced by one conversion reaction to the other conversion reaction, for consumption therein. One of the conversion reactions is an oxidation reaction, and the energy that it yields is used to drive the other conversion reaction, a reduction. The reduction reaction is carried out in a solid polymer electrolyte electrolytic reactor. The overall process is energy efficient and yields no waste by-products. A particular embodiment of the process in the production of nitrogen-15-enriched nitric acid.

Michaels, E.D.

1981-02-25

10

Efficiency evaluation of oxygen enrichment in energy conversion processes  

SciTech Connect

The extent to which energy conversion efficiencies can be increased by using oxygen or oxygen-enriched air for combustion was studied. Combustion of most fuels with oxygen instead of air was found to have five advantages: increases combustion temperature and efficiency, improves heat transfer at high temperatures, reduces nitrous oxide emissions, permits a high ration of exhaust gas recirculation and allows combustion of certain materials not combustible in air. The same advantages, although to a lesser degree, are apparent with oxygen-enriched air. The cost-effectiveness of the process must necessarily be improved by about 10% when using oxygen instead of air before such use could become justifiable on purely economic terms. Although such a modest increase appears to be attainable in real situations, this study ascertained that it is not possible to generally assess the economic gains. Rather, each case requires its own evaluation. For certain processes industry has already proven that the use of oxygen leads to more efficient plant operation. Several ideas for essentially new applications are described. Specifically, when oxygen is used with exhaust gas recirculation in external or internal combustion engines. It appears also that the advantages of pulse combustion can be amplified further if oxygen is used. When burning wet fuels with oxygen, direct steam generation becomes possible. Oxygen combustion could also improve processes for in situ gasification of coals, oil shales, peats, and other wet fuels. Enhanced oil recovery by fire flooding methods might also become more effective if oxygen is used. The cold energy contained in liquid oxygen can be substantially recovered in the low end of certain thermodynamic cycles. Further efforts to develop certain schemes for using oxygen for combustion appear to be justified from both the technical and economic viewpoints.

Bomelburg, H.J.

1983-12-01

11

77 FR 33253 - Regulatory Guide 8.24, Revision 2, Health Physics Surveys During Enriched Uranium-235 Processing...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Health Physics Surveys During Enriched Uranium-235 Processing and Fuel Fabrication...INFORMATION CONTACT: Gregory Chapman, Uranium Enrichment Branch, Division of Fuel Cycle...Health Physics Surveys During Enriched Uranium-235 Processing and Fuel...

2012-06-05

12

Enrichment and Fundamental Optical Processes of Armchair Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

The armchair variety of single-wall carbon nanotubes (SWCNTs) is the only nanotube species that behaves as a metal with no electronic band gap and massless carriers, making them ideally suited to probe fundamental questions of many-body physics of one-dimensional conductors as well as to serve in applications such as highcurrent power transmission cables. However, current methods of nanotube synthesis produce bulk material comprising of a mixture of nanotube lengths, diameters, wrapping angles, and electronic types due to the inability to control the growth process at the nanometer level. As a result, measurements of as-grown SWCNTs produce a superposition of electrical and optical responses from multiple SWCNT species. This thesis demonstrates production of aqueous suspensions composed almost entirely of armchair SWCNTs using a post-synthesis separation method employing density gradient ultracentrifugation (DGU) to separate different SWCNT types based on their mass density and surfactant-specific interactions. Resonant Raman spectroscopy determines the relative abundances of each nanotube species, before and after DGU, by measuring the integrated intensity of the radial breathing mode, the diameter-dependent radial vibration of the SWCNT perpendicular to its main axis, and quantifies the degree of enrichment of bulk nanotube samples to exclusively armchair tubes. Raman spectroscopy of armchair-enriched samples of the G-band mode, which is composed of longitudinal (G-) and circumferential (G+) vibrations oscillating parallel and perpendicular to the tube axis, shows that the G- peak, long-held to be an indicator for the presence of metallic SWCNTs, appears only when electronic resonance with narrow-gap semiconducting SWCNTs occurs and shows only the G+ component in spectra containing only armchair species. Finally, by combining optical absorption measurements with nanotube composition as determined earlier via Raman scattering, peak fitting of absorption spectra indicates that interband transitions of armchair SWCNTs are strongly excitonic as shown by the highly symmetric peak lineshapes, a property normally attributed to semiconductors. Such lineshapes allow classification of armchair SWCNTs as a unique hybrid class of optical nanomaterial. Combining absorption and Raman scattering measurements establishes a distinct optical signature that describes the fundamental optical processes within armchair SWCNTs and lays the foundation for future studies of many-body photophysics and electrical applications.

Haroz, Erik H.

13

Enrichment of processed pseudogene transcripts in L1-ribonucleoprotein particles  

PubMed Central

Long INterspersed Elements (LINE-1s, L1s) are responsible for over one million retrotransposon insertions and 8000 processed pseudogenes (PPs) in the human genome. An active L1 encodes two proteins (ORF1p and ORF2p) that bind with L1 RNA and form L1-ribonucleoprotein particles (RNPs). Although it is believed that the RNA-binding property of ORF1p is critical to recruit other mobile RNAs to the RNP, the identity of recruited RNAs is largely unknown. Here, we used crosslinking and immunoprecipitation followed by deep sequencing to identify RNA components of L1-RNPs. Our results show that in addition to retrotransposed RNAs [L1, Alu and SINE-VNTR-Alu (SVA)], L1-RNPs are enriched with cellular mRNAs, which have PPs in the human genome. Using purified L1-RNPs, we show that PP-source RNAs preferentially serve as ORF2p templates in a reverse transcriptase assay. In addition, we find that exogenous ORF2p binds endogenous ORF1p, allowing reverse transcription of the same PP-source RNAs. These data demonstrate that interaction of a cellular RNA with the L1-RNP is an inside track to PP formation. PMID:23696454

Mandal, Prabhat K.; Ewing, Adam D.; Hancks, Dustin C.; Kazazian, Haig H.

2013-01-01

14

Enrichment of processed pseudogene transcripts in L1-ribonucleoprotein particles.  

PubMed

Long INterspersed Elements (LINE-1s, L1s) are responsible for over one million retrotransposon insertions and 8000 processed pseudogenes (PPs) in the human genome. An active L1 encodes two proteins (ORF1p and ORF2p) that bind with L1 RNA and form L1-ribonucleoprotein particles (RNPs). Although it is believed that the RNA-binding property of ORF1p is critical to recruit other mobile RNAs to the RNP, the identity of recruited RNAs is largely unknown. Here, we used crosslinking and immunoprecipitation followed by deep sequencing to identify RNA components of L1-RNPs. Our results show that in addition to retrotransposed RNAs [L1, Alu and SINE-VNTR-Alu (SVA)], L1-RNPs are enriched with cellular mRNAs, which have PPs in the human genome. Using purified L1-RNPs, we show that PP-source RNAs preferentially serve as ORF2p templates in a reverse transcriptase assay. In addition, we find that exogenous ORF2p binds endogenous ORF1p, allowing reverse transcription of the same PP-source RNAs. These data demonstrate that interaction of a cellular RNA with the L1-RNP is an inside track to PP formation. PMID:23696454

Mandal, Prabhat K; Ewing, Adam D; Hancks, Dustin C; Kazazian, Haig H

2013-09-15

15

Autoxidation of oil emulsions during the Artemia enrichment process  

Microsoft Academic Search

Autoxidation in three Artemia enrichment emulsions (cod liver oil, tuna orbital oil, and Super Selco (Artemia Systems N.V., Belgium)) were monitored over a 23-h period. Percentage concentrations of docosahexaenoic acid (DHA, 22:6n ? 3), eicosapentaenoic acid (EPA, 20:5n-3), total polyun-saturated, monounsaturated and saturated fatty acids, as well as DHA:EPA ratios were measured in (a) the enriched Artemia nauplii (b) control

L. A. McEvoy; J. C. Navarro; J. G. Bell; J. R. Sargent

1995-01-01

16

NEW ABUNDANCE DETERMINATIONS OF CADMIUM, LUTETIUM, AND OSMIUM IN THE r-PROCESS ENRICHED STAR BD +17 3248  

E-print Network

NEW ABUNDANCE DETERMINATIONS OF CADMIUM, LUTETIUM, AND OSMIUM IN THE r-PROCESS ENRICHED STAR BD +17 ABUNDANCE DETERMINATIONS OF CADMIUM, LUTETIUM, AND OSMIUM IN THE r-PROCESS ENRICHED STAR BD +17 3248, Ian U

Cowan, John

17

Process and apparatus for isotopic enrichment using lasers  

Microsoft Academic Search

A process is described for the separation of a first isotope of an element from other isotopes of the element. The isotopes are present as a mixture in an isotopic compound, and one of the isotopic compounds is excitable by light at a wavelength where the other isotopic compounds remain stable. The process consists of: coating discrete, small bead particles,

E. J. Lahoda; H. A. Burgman; T. S. Snyder

1986-01-01

18

Enrichment of the r-process Element Europium in the Galactic Halo  

E-print Network

We investigate the enrichment of europium, as a representative of r-process elements, in the Galactic halo. In present chemical evolution models, stars are assumed to be formed through shock processes by supernovae (SNe). The enrichment of the interstellar medium is calculated by a one-zone approach. The observed large dispersions in [Eu/Fe] for halo stars, converging with increasing metallicity, can be explained with our models. In addition, the mass range of SNe for the {\\it r}-process site is constrained to be either stars of $8-10 M_\\odot$ or $\\gtrsim 30 M_\\odot$.

Yuhri Ishimaru; Shinya Wanajo

1998-12-03

19

Environmental enrichment alters neuronal processing in the nucleus accumbens core during appetitive conditioning  

Microsoft Academic Search

Although the core region of the nucleus accumbens (NAcc) has been implicated in motor control and the acquisition of appetitive learning, these processes are altered by environmental experience. To assess how environment influences neuronal processing in NAcc core, we recorded single-unit activity during acquisition of an appetitive learning task in which rats reared in an environmentally enriched condition (EC) learned

David A. Wood; George V. Rebec

2009-01-01

20

s-process Enrichment in the Planetary Nebula NGC 3918  

E-print Network

We present deep, high-resolution (R~40000) UVES at VLT spectrophotometric data of the planetary nebula NGC 3918. This is one of the deepest spectra ever taken of a planetary nebula. We have identified and measured more than 700 emission lines and, in particular, we have detected very faint lines of several neutron-capture elements (s-process elements: Kr, Xe and Rb) that enable us to compute their chemical abundances with unprecedented accuracy, thus constraining the efficiency of the s-process and convective dredge-up.

García-Rojas, J; Luridiana, V; Sterling, N C; Morisset, C

2014-01-01

21

Magnetic separation as a plutonium residue enrichment process  

SciTech Connect

We have subjected several plutonium contaminated residues to Open Gradient Magnetic Separation (OGMS) on an experimental scale. Separation of graphite, bomb reduction sand, and bomb reduction sand, and bomb reduction sand, slag, and crucible, resulted in a plutonium rich fraction and a plutonium lean fraction. The lean fraction varied between about 20% to 85% of the feed bulk. The plutonium content of the lean fraction can be reduced from about 2% in the feed to the 0.1% to 0.5% range dependent on the portion of the feed rejected to this lean fraction. These values are low enough in plutonium to meet economic discard limits and be considered for direct discard. Magnetic separation of direct oxide reduction and electrorefining pyrochemical salts gave less favorable results. While a fraction very rich in plutonium could be obtained, the plutonium content of the lean fraction was to high for direct discard. This may still have chemical processing applications. OGMS experiments at low magnetic field strength on incinerator ash did give two fractions but the plutonium content of each fraction was essentially identical. Thus, no chemical processing advantage was identified for magnetic separation of this residue. The detailed results of these experiments and the implications for OGMS use in recycle plutonium processing are discussed. 4 refs., 3 figs., 9 tabs.

Avens, L.R.; McFarlan, J.T.; Gallegos, U.F.

1989-01-01

22

Method for thermal processing alumina-enriched spinel single crystals  

DOEpatents

A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly. 12 figs.

Jantzen, C.M.

1995-05-09

23

Method for thermal processing alumina-enriched spinel single crystals  

DOEpatents

A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly.

Jantzen, Carol M. (Aiken, SC)

1995-01-01

24

Environmental acoustic enrichment promotes recovery from developmentally degraded auditory cortical processing.  

PubMed

It has previously been shown that environmental enrichment can enhance structural plasticity in the brain and thereby improve cognitive and behavioral function. In this study, we reared developmentally noise-exposed rats in an acoustic-enriched environment for ?4 weeks to investigate whether or not enrichment could restore developmentally degraded behavioral and neuronal processing of sound frequency. We found that noise-exposed rats had significantly elevated sound frequency discrimination thresholds compared with age-matched naive rats. Environmental acoustic enrichment nearly restored to normal the behavioral deficit resulting from early disrupted acoustic inputs. Signs of both degraded frequency selectivity of neurons as measured by the bandwidth of frequency tuning curves and decreased long-term potentiation of field potentials recorded in the primary auditory cortex of these noise-exposed rats also were reversed partially. The observed behavioral and physiological effects induced by enrichment were accompanied by recovery of cortical expressions of certain NMDA and GABAA receptor subunits and brain-derived neurotrophic factor. These studies in a rodent model show that environmental acoustic enrichment promotes recovery from early noise-induced auditory cortical dysfunction and indicate a therapeutic potential of this noninvasive approach for normalizing neurological function from pathologies that cause hearing and associated language impairments in older children and adults. PMID:24741032

Zhu, Xiaoqing; Wang, Fang; Hu, Huifang; Sun, Xinde; Kilgard, Michael P; Merzenich, Michael M; Zhou, Xiaoming

2014-04-16

25

Assessment of the Interstellar Processes Leading to Deuterium Enrichment in Meteoritic Organics  

NASA Technical Reports Server (NTRS)

The presence of isotopic anomalies is the most unequivocal demonstration that meteoritic material contains circumstellar or interstellar components. In the case of organic compounds in meteorites and interplanetary dust particles (IDPs), the most useful isotopic tracer has been deuterium (D). We discuss four processes that are expected to lead to D enrichment in interstellar materials and describe how their unique characteristics can be used to assess their relative importance for the organics in meteorites. These enrichment processes are low temperature gas phase ion-molecule reactions, low temperature gas-grain reactions, gas phase unimolecular photodissociation, and ultraviolet photolysis in D-enriched ice mantles. Each of these processes is expected to be associated with distinct regiochemical signatures (D placement on the product molecules, correlation with specific chemical functionalities, etc.), especially in the molecular population of polycyclic aromatic hydrocarbons (PAHs). We describe these differences and discuss how they may be used to delineate the various interstellar processes that may have contributed to meteoritic D enrichments. We also briefly discuss how these processes may affect the isotopic distributions in C, 0, and N in the same compounds.

Sandford, Scott A.; Bernstein, Max P.; Dworkin, Jason P.; DeVincenzi, Donald L. (Technical Monitor)

2001-01-01

26

Chemical processes for the extreme enrichment of tellurium into marine ferromanganese oxides  

NASA Astrophysics Data System (ADS)

Tellurium, an element of growing economic importance, is extremely enriched in marine ferromanganese oxides. We investigated the mechanism of this enrichment using a combination of spectroscopic analysis and adsorption/coprecipitation experiments. X-ray Absorption Near-Edge Structure (XANES) analysis showed that in adsorption/coprecipitation systems, Te(IV) was oxidized on ?-MnO2 and not oxidized on ferrihydrite. Extended X-ray Absorption Fine Structure (EXAFS) analysis showed that both Te(IV) and Te(VI) were adsorbed on the surface of ?-MnO2 and ferrihydrite via formation of inner-sphere complexes. In addition, Te(VI) can be structurally incorporated into the linkage of Fe octahedra through a coprecipitation process because of its molecular geometry that is similar to the Fe octahedron. The largest distribution coefficient obtained in the adsorption/coprecipitation experiments was for the Te(VI)/ferrihydrite coprecipitation system, and it was comparable to those calculated from the distribution between natural ferromanganese oxides and seawater. Our XAFS and micro-focused X-ray fluorescence (?-XRF) mapping of natural ferromanganese oxides showed that Te was structurally incorporated as Te(VI) in Fe (oxyhydr)oxide phases. We conclude that the main process for the enrichment of Te in ferromanganese oxides is structural incorporation of Te(VI) into Fe (oxyhydr)oxide phases through coprecipitation. This mechanism can explain the unique degree of enrichment of Te compared with other oxyanions, which are mainly enriched via adsorption on the surface of the solid structures. In particular, the great contrast in the distributions of Te and Se is caused by their oxidized species: (i) the similar geometry of the Te(VI) molecule to Fe octahedron, and (ii) quite soluble nature of Se(VI). Coexisting Mn oxide phases may promote structural incorporation of Te(VI) by oxidation of Te(IV), although the surface oxidation itself may not work as the critical enrichment process as in the case of some cations. This enrichment mechanism also means that ferromanganese oxides mainly scavenge dominant Te(VI) species from seawater and do not affect its species distribution in seawater, as described in a previous model. The variation in Te abundances and the correlation of Te concentration with the growth rate of natural ferromanganese oxides are consistent with the coprecipitation mechanism.

Kashiwabara, Teruhiko; Oishi, Yasuko; Sakaguchi, Aya; Sugiyama, Toshiki; Usui, Akira; Takahashi, Yoshio

2014-04-01

27

Resin-assisted Enrichment of N-terminal Peptides for Characterizing Proteolytic Processing  

SciTech Connect

Proteolytic processing is a ubiquitous, irreversible posttranslational modification that plays an important role in cellular regulation in all living organisms. Herein we report a resin-assisted positive selection method for specifically enriching protein N-terminal peptides to facilitate the characterization of proteolytic processing events by liquid chromatography-tandem mass spectrometry. In this approach, proteins are initially reduced and alkylated and their lysine residues are converted to homoarginines. Then, protein N-termini are selectively converted to reactive thiol groups. We demonstrate that these sequential reactions were achieved with nearly quantitative efficiencies. Thiol-containing N-terminal peptides are then captured (>98% efficiency) by a thiol-affinity resin, a significant improvement over the traditional avidin/biotin enrichment. Application to cell lysates of Aspergillus niger, a filamentous fungus of interest for biomass degradation, enabled the identification of 1672 unique protein N-termini and proteolytic cleavage sites from 690 unique proteins.

Kim, Jong Seo; Dai, Ziyu; Aryal, Uma K.; Moore, Ronald J.; Camp, David G.; Baker, Scott E.; Smith, Richard D.; Qian, Weijun

2013-06-17

28

A New Analysis of s-process Enrichments in Planetary Nebulae  

NASA Astrophysics Data System (ADS)

We present a new analysis of selenium and krypton enrichments in planetary nebulae (PNe), using recently determined atomic data for these elements. Se and Kr are the two most widely-detected neutron-capture elements in PNe, and can be enriched by s-process nucleosynthesis in PN progenitor stars. With the photoionization code Cloudy (Ferland et al. 2013, RMxA&A, 49, 1), we computed grids of models that span the range of physical conditions in most PNe to investigate the ionization balance of Se and Kr. The new atomic data were tested by modeling 15 PNe that exhibit emission from multiple Kr ions. We found systematic discrepancies between the modeled and observed Kr lines, which could not be satisfactorily explained by observational uncertainties or approximations in the models. The observed ionization balance is reproduced more accurately by empirically adjusting the photoionization cross sections of Kr+—Kr3+ within their cited uncertainties, and the dielectronic recombination rate coefficients by slightly larger amounts. We present new analytical ionization correction factors for Se and Kr, based on correlations between the ionic fractions of detected Se and Kr ions and those of routinely observed O, Ar, and S ions. The correction factors are applied to the K band survey of Sterling & Dinerstein (2008, ApJS, 174, 158) to derive improved Se and Kr abundances in 120 PNe. The revised abundances are 0.1—0.3 dex lower than the previous values in most PNe, reducing the estimated fraction of enriched objects from 52% to 37%. However, this figure depends on the assumed initial abundances of Se and Kr in the progenitor stars, which may be subsolar in some cases and may differ for objects belonging to different stellar populations. We find that the primary conclusions of Sterling & Dinerstein still hold: Kr is more strongly enriched than Se in PNe, in accordance with nucleosynthetic predictions; PNe with more massive progenitors show little if any s-process enrichment; and Se and Kr enrichments correlate positively with nebular C/O ratios. NCS acknowledges support for this work from NSF Astronomy and Astrophysics Postdoctoral Fellowship AST-901432, and HLD received support from NSF grant AST-0708245.

Sterling, Nicholas C.; Porter, Ryan; Dinerstein, Harriet L.

2015-01-01

29

Prompt Iron Enrichment, Two r-Process Components, and Abundances in Very Metal-Poor Stars  

E-print Network

We present a model to explain the wide range of abundances for heavy r-process elements (mass number A > 130) at low [Fe/H]. This model requires rapid star formation and/or an initial population of supermassive stars in the earliest condensed clots of matter to provide a prompt or initial Fe inventory. Subsequent Fe and r-process enrichment was provided by two types of supernovae: one producing heavy r-elements with no Fe on a rather short timescale and the other producing light r-elements (A < or = 130) with Fe on a much longer timescale.

G. J. Wasserburg; Y. -Z. Qian

1999-11-30

30

Using Process Load Cell Information for IAEA Safeguards at Enrichment Plants  

SciTech Connect

Uranium enrichment service providers are expanding existing enrichment plants and constructing new facilities to meet demands resulting from the shutdown of gaseous diffusion plants, the completion of the U.S.-Russia highly enriched uranium downblending program, and the projected global renaissance in nuclear power. The International Atomic Energy Agency (IAEA) conducts verification inspections at safeguarded facilities to provide assurance that signatory States comply with their treaty obligations to use nuclear materials only for peaceful purposes. Continuous, unattended monitoring of load cells in UF{sub 6} feed/withdrawal stations can provide safeguards-relevant process information to make existing safeguards approaches more efficient and effective and enable novel safeguards concepts such as information-driven inspections. The IAEA has indicated that process load cell monitoring will play a central role in future safeguards approaches for large-scale gas centrifuge enrichment plants. This presentation will discuss previous work and future plans related to continuous load cell monitoring, including: (1) algorithms for automated analysis of load cell data, including filtering methods to determine significant weights and eliminate irrelevant impulses; (2) development of metrics for declaration verification and off-normal operation detection ('cylinder counting,' near-real-time mass balancing, F/P/T ratios, etc.); (3) requirements to specify what potentially sensitive data is safeguards relevant, at what point the IAEA gains on-site custody of the data, and what portion of that data can be transmitted off-site; (4) authentication, secure on-site storage, and secure transmission of load cell data; (5) data processing and remote monitoring schemes to control access to sensitive and proprietary information; (6) integration of process load cell data in a layered safeguards approach with cross-check verification; (7) process mock-ups constructed to provide simulated load cell data; (8) hardware and software implementation for process load cell data collection; (9) costs associated with unattended monitoring of load cells (for both operator and inspector) weighed against the potential benefits of having access to such data; (10) results from field tests of load cell data collection systems in operating facilities; and (11) use of unattended load cell data to increase efficiency of on-site inspection schedules and activities.

Laughter, Mark D [ORNL; Whitaker, J Michael [ORNL; Howell, John [University of Glasgow

2010-01-01

31

Reorganization in processing of spectral and temporal input in the rat posterior auditory field induced by environmental enrichment  

PubMed Central

Environmental enrichment induces powerful changes in the adult cerebral cortex. Studies in primary sensory cortex have observed that environmental enrichment modulates neuronal response strength, selectivity, speed of response, and synchronization to rapid sensory input. Other reports suggest that nonprimary sensory fields are more plastic than primary sensory cortex. The consequences of environmental enrichment on information processing in nonprimary sensory cortex have yet to be studied. Here we examine physiological effects of enrichment in the posterior auditory field (PAF), a field distinguished from primary auditory cortex (A1) by wider receptive fields, slower response times, and a greater preference for slowly modulated sounds. Environmental enrichment induced a significant increase in spectral and temporal selectivity in PAF. PAF neurons exhibited narrower receptive fields and responded significantly faster and for a briefer period to sounds after enrichment. Enrichment increased time-locking to rapidly successive sensory input in PAF neurons. Compared with previous enrichment studies in A1, we observe a greater magnitude of reorganization in PAF after environmental enrichment. Along with other reports observing greater reorganization in nonprimary sensory cortex, our results in PAF suggest that nonprimary fields might have a greater capacity for reorganization compared with primary fields. PMID:22131375

Jakkamsetti, Vikram; Chang, Kevin Q.

2012-01-01

32

Reorganization in processing of spectral and temporal input in the rat posterior auditory field induced by environmental enrichment.  

PubMed

Environmental enrichment induces powerful changes in the adult cerebral cortex. Studies in primary sensory cortex have observed that environmental enrichment modulates neuronal response strength, selectivity, speed of response, and synchronization to rapid sensory input. Other reports suggest that nonprimary sensory fields are more plastic than primary sensory cortex. The consequences of environmental enrichment on information processing in nonprimary sensory cortex have yet to be studied. Here we examine physiological effects of enrichment in the posterior auditory field (PAF), a field distinguished from primary auditory cortex (A1) by wider receptive fields, slower response times, and a greater preference for slowly modulated sounds. Environmental enrichment induced a significant increase in spectral and temporal selectivity in PAF. PAF neurons exhibited narrower receptive fields and responded significantly faster and for a briefer period to sounds after enrichment. Enrichment increased time-locking to rapidly successive sensory input in PAF neurons. Compared with previous enrichment studies in A1, we observe a greater magnitude of reorganization in PAF after environmental enrichment. Along with other reports observing greater reorganization in nonprimary sensory cortex, our results in PAF suggest that nonprimary fields might have a greater capacity for reorganization compared with primary fields. PMID:22131375

Jakkamsetti, Vikram; Chang, Kevin Q; Kilgard, Michael P

2012-03-01

33

A Monte Carlo Analysis of Gas Centrifuge Enrichment Plant Process Load Cell Data  

SciTech Connect

As uranium enrichment plants increase in number, capacity, and types of separative technology deployed (e.g., gas centrifuge, laser, etc.), more automated safeguards measures are needed to enable the IAEA to maintain safeguards effectiveness in a fiscally constrained environment. Monitoring load cell data can significantly increase the IAEA s ability to efficiently achieve the fundamental safeguards objective of confirming operations as declared (i.e., no undeclared activities), but care must be taken to fully protect the operator s proprietary and classified information related to operations. Staff at ORNL, LANL, JRC/ISPRA, and University of Glasgow are investigating monitoring the process load cells at feed and withdrawal (F/W) stations to improve international safeguards at enrichment plants. A key question that must be resolved is what is the necessary frequency of recording data from the process F/W stations? Several studies have analyzed data collected at a fixed frequency. This paper contributes to load cell process monitoring research by presenting an analysis of Monte Carlo simulations to determine the expected errors caused by low frequency sampling and its impact on material balance calculations.

Garner, James R [ORNL; Whitaker, J Michael [ORNL

2013-01-01

34

Multivariate analysis of the heterogeneous geochemical processes controlling arsenic enrichment in a shallow groundwater system.  

PubMed

The effects of various geochemical processes on arsenic enrichment in a high-arsenic aquifer at Jianghan Plain in Central China were investigated using multivariate models developed from combined adaptive neuro-fuzzy inference system (ANFIS) and multiple linear regression (MLR). The results indicated that the optimum variable group for the AFNIS model consisted of bicarbonate, ammonium, phosphorus, iron, manganese, fluorescence index, pH, and siderite saturation. These data suggest that reductive dissolution of iron/manganese oxides, phosphate-competitive adsorption, pH-dependent desorption, and siderite precipitation could integrally affect arsenic concentration. Analysis of the MLR models indicated that reductive dissolution of iron(III) was primarily responsible for arsenic mobilization in groundwaters with low arsenic concentration. By contrast, for groundwaters with high arsenic concentration (i.e., > 170 ?g/L), reductive dissolution of iron oxides approached a dynamic equilibrium. The desorption effects from phosphate-competitive adsorption and the increase in pH exhibited arsenic enrichment superior to that caused by iron(III) reductive dissolution as the groundwater chemistry evolved. The inhibition effect of siderite precipitation on arsenic mobilization was expected to exist in groundwater that was highly saturated with siderite. The results suggest an evolutionary dominance of specific geochemical process over other factors controlling arsenic concentration, which presented a heterogeneous distribution in aquifers. Supplemental materials are available for this article. Go to the publisher's online edition of the Journal of Environmental Science and Health, Part A, to view the supplemental file. PMID:24345245

Huang, Shuangbing; Liu, Changrong; Wang, Yanxin; Zhan, Hongbin

2014-01-01

35

CONCEPTUAL PROCESS DESCRIPTION FOR THE MANUFACTURE OF LOW-ENRICHED URANIUM-MOLYBDENUM FUEL  

SciTech Connect

The National Nuclear Security Agency Global Threat Reduction Initiative (GTRI) is tasked with minimizing the use of high-enriched uranium (HEU) worldwide. A key component of that effort is the conversion of research reactors from HEU to low-enriched uranium (LEU) fuels. The GTRI Convert Fuel Development program, previously known as the Reduced Enrichment for Research and Test Reactors program was initiated in 1978 by the United States Department of Energy to develop the nuclear fuels necessary to enable these conversions. The program cooperates with the research reactors’ operators to achieve this goal of HEU to LEU conversion without reduction in reactor performance. The programmatic mandate is to complete the conversion of all civilian domestic research reactors by 2014. These reactors include the five domestic high-performance research reactors (HPRR), namely: the High Flux Isotope Reactor at the Oak Ridge National Laboratory, the Advanced Test Reactor at the Idaho National Laboratory, the National Bureau of Standards Reactor at the National Institute of Standards and Technology, the Missouri University Research Reactor at the University of Missouri–Columbia, and the MIT Reactor-II at the Massachusetts Institute of Technology. Characteristics for each of the HPRRs are given in Appendix A. The GTRI Convert Fuel Development program is currently engaged in the development of a novel nuclear fuel that will enable these conversions. The fuel design is based on a monolithic fuel meat (made from a uranium-molybdenum alloy) clad in Al-6061 that has shown excellent performance in irradiation testing. The unique aspects of the fuel design, however, necessitate the development and implementation of new fabrication techniques and, thus, establishment of the infrastructure to ensure adequate fuel fabrication capability. A conceptual fabrication process description and rough estimates of the total facility throughput are described in this document as a basis for establishing preconceptual fabrication facility designs.

Daniel M. Wachs; Curtis R. Clark; Randall J. Dunavant

2008-02-01

36

Simulation of a four-bed pressure swing adsorption process for oxygen enrichment  

SciTech Connect

Pressure swing adsorption (PSA) is a cyclic process for gas purification and separation. More and more commercial separation processes employing PSA technology have been developed since the first patent of a PSA process in the US was described. This separation technology needs lower energy and is less costly than the conventional separation processes like absorption and distillation, and it can provide a very efficient and flexible means of gas separation. Dynamic simulation with the valve equation approach of a four-bed pressure swing adsorption (PSA) process for oxygen enrichment over zeolite 5A was performed. Product pressurization, feed pressurization, production, blowdown, purge, and pressure equalization are included in this process. The numerical results were compared to the experimental results of Chiang et al. (1994) and gave reasonable agreements. The effects of production rate and purge rate on the purity and recovery were also explored by simulation. When breakthrough did not occur for the depressurizing bed during the pressure equalization step, operation at the minimum purge rate gave a relatively high recovery for producing a product of purity more than 95% oxygen. When breakthrough occurred, the theoretical results show that, for a fixed production rate, there is a purge rate giving the maximum recovery and a different purge rate giving the highest purity.

Chengtung Chou; Wen Chun Huang (National Central Univ., Chung-Li (Taiwan, Province of China). Dept. of Chemical Engineering)

1994-05-01

37

Property and process correlations for iron-enriched basalt waste forms  

SciTech Connect

Correlations of thermodynamic properties and process parameters of high-temperature slag for a range of compositions of iron-enriched basalt are presented. The quantification of the properties of this complex mixture can assist in the design and monitoring of high-temperature melting systems for the treatment of radioactive and hazardous wastes at the Idaho National Engineering Laboratory. The buried and stored wastes at the INEL Radioactive Waste Management Complex have a similar composition to iron-enriched basalt after oxidation of organics. The properties correlated are the viscosity, electrical conductivity, refractory corrosion, and recrystallization temperature. The correlations are expressed as a function of input waste-soil mixture composition, alkali concentration, and slag temperature. An application to determine the effect of alkali flux on slag temperature, leach rate, and volume reduction is presented. Though the correlations are for mixtures of soil and waste with average transuranic-contaminated waste compositions, it appears that good approximations for other waste streams and glass-ceramic waste forms can be obtained because of similarities in composition.

Grandy, J.D.; Eddy, T.L.; Anderson, G.L.

1993-02-01

38

Exploring Input Processing in the Classroom: An Experimental Comparison of Processing Instruction and Enriched Input  

ERIC Educational Resources Information Center

The research reported here tests the claim made in the Input Processing approach to second language (L2) acquisition that interpreting the meaning of language form is essential for learning. This claim has been put forward as an underlying part of the pedagogical package known as Processing Instruction (PI) (VanPatten, 1996, 2002a, 2004). Two…

Marsden, Emma

2006-01-01

39

The Problem with Continuity of Knowledge in Enrichment Plant Process Monitoring  

SciTech Connect

It has been three years since the new Gas Centrifuge Enrichment Plant (GCEP) Model Safeguards Approach was approved for implementation by the International Atomic Energy Agency’s Department of Safeguards. Among its recommendations are safeguard measures that place greater emphasis on instrumentation in the process area (Cooley 2007). Irrespective of the compelling technologies, an often overlooked impediment to the application of such instrumentation is maintenance of continuity of knowledge on material that has been identified as abnormal. Any instrument purporting to identify problems in the process area should include some means of containing or monitoring that material until International Atomic Energy Agency (IAEA) inspectors can arrive to confirm the discrepancy. If no containment or surveillance is employed in the interim, and no discrepancy or anomaly is subsequently uncovered in storage cylinders, it is unclear what follow-up action inspectors can take. Some CoK measures have been proposed, but they usually involve an array of cameras or host-applied seals—options that may require a backup system of their own.

Curtis, Michael M.

2009-08-01

40

Process for producing enriched uranium having a .sup.235 U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage  

Microsoft Academic Search

An uranium enrichment process capable of producing an enriched uranium, having a .sup.235 U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower .sup.235 U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UF.sub.6 tails storage and sharply reduce fluorine

James A. Horton; Hayden Jr. Howard W

1995-01-01

41

Local finite element enrichment strategies for 2D contact computations and a corresponding post-processing scheme  

NASA Astrophysics Data System (ADS)

Recently an enriched contact finite element formulation has been developed that substantially increases the accuracy of contact computations while keeping the additional numerical effort at a minimum reported by Sauer (Int J Numer Meth Eng, 87: 593-616, 2011). Two enrich-ment strategies were proposed, one based on local p-refinement using Lagrange interpolation and one based on Hermite interpolation that produces C 1-smoothness on the contact surface. Both classes, which were initially considered for the frictionless Signorini problem, are extended here to friction and contact between deformable bodies. For this, a symmetric contact formulation is used that allows the unbiased treatment of both contact partners. This paper also proposes a post-processing scheme for contact quantities like the contact pressure. The scheme, which provides a more accurate representation than the raw data, is based on an averaging procedure that is inspired by mortar formulations. The properties of the enrichment strategies and the corresponding post-processing scheme are illustrated by several numerical examples considering sliding and peeling contact in the presence of large deformations.

Sauer, Roger A.

2013-08-01

42

Process for recovering evolved hydrogen enriched with at least one heavy hydrogen isotope  

DOEpatents

This invention relates to a separation means and method for enriching a hydrogen atmosphere with at least one heavy hydrogen isotope by using a solid titaniun alloy hydride. To this end, the titanium alloy hydride containing at least one metal selected from the group consisting of vanadium, chromium, manganese, molybdenum, iron, cobalt and nickel is contacted with a circulating gaseous flow of hydrogen containing at least one heavy hydrogen isotope at a temperature in the range of -20.degree. to +40.degree. C and at a pressure above the dissociation pressure of the hydrided alloy selectively to concentrate at least one of the isotopes of hydrogen in the hydrided metal alloy. The contacting is continued until equilibrium is reached, and then the gaseous flow is isolated while the temperature and pressure of the enriched hydride remain undisturbed selectively to isolate the hydride. Thereafter, the enriched hydrogen is selectively recovered in accordance with the separation factor (S.F.) of the alloy hydride employed.

Tanaka, John (Storrs, CT); Reilly, Jr., James J. (Bellport, NY)

1978-01-01

43

Processing, physico-chemical, sensory and nutritional evaluation of protein, mineral and vitamin enriched peanut chikki - an Indian traditional sweet.  

PubMed

Chikki, a popular Indian traditional sweet snack prepared from peanut was enriched with protein, minerals and vitamins by incorporating soy protein isolate, calcium carbonate, ferrous fumerate, vitamin A and folic acid to meet the growing demand for health foods. The enriched nutra chikki was evaluated for physico-chemical characteristics such as moisture, texture, peroxide value (PV), fatty acid composition in comparison with control peanut chikki. Nutra chikki, which had initial moisture content of 2-3%, did not alter much up to 60 days of storage at 27 °C and 37 °C. PV increased gradually at 27 °C, whereas at 37 °C, it was higher. Hardness of nutra chikki did not change significantly when stored at 27 °C up to 105 days, but at 37 °C a gradual increase in hardness was observed after 45 days. These results of nutra chikki were similar and comparable with those of control chikki. Nutra chikki had 18% protein, 20% fat, 6.42% Ca, 1.7% Fe, 4000 ?g vitamin A and 2660 ?g folic acid. Protein digestibility corrected amino acid score of nutra chikki was 0.78 whereas that of control chikki was 0.73. The fatty acid composition of control and nutra chikki was same as both contain peanuts as oil source. The formulation and process parameters for preparation of protein, mineral and vitamin enriched peanut chikki, were standardized. The storage stability and quality parameters of enriched chikki were comparable with those of control chikki. PMID:24426063

Pallavi, Byrappa Vasu; Chetana, Ramakrishna; Reddy, Sunkireddy Yella

2014-01-01

44

Developing Creative Thinking in a Gifted Sport Enrichment Program and the Crucial Role of Attention Processes  

ERIC Educational Resources Information Center

A six-month longitudinal study (N = 33) proved the influence of a diversified sport enrichment program on the development of creative thinking in team ball sports among gifted children. A contrast between a gifted control group and a non-gifted treatment group showed that the creative performance of the gifted children significantly improved…

Memmert, Daniel

2006-01-01

45

A signal processing approach for enriched region detection in RNA polymerase II ChIP-seq data  

PubMed Central

Background RNA polymerase II (PolII) is essential in gene transcription and ChIP-seq experiments have been used to study PolII binding patterns over the entire genome. However, since PolII enriched regions in the genome can be very long, existing peak finding algorithms for ChIP-seq data are not adequate for identifying such long regions. Methods Here we propose an enriched region detection method for ChIP-seq data to identify long enriched regions by combining a signal denoising algorithm with a false discovery rate (FDR) approach. The binned ChIP-seq data for PolII are first processed using a non-local means (NL-means) algorithm for purposes of denoising. Then, a FDR approach is developed to determine the threshold for marking enriched regions in the binned histogram. Results We first test our method using a public PolII ChIP-seq dataset and compare our results with published results obtained using the published algorithm HPeak. Our results show a high consistency with the published results (80-100%). Then, we apply our proposed method on PolII ChIP-seq data generated in our own study on the effects of hormone on the breast cancer cell line MCF7. The results demonstrate that our method can effectively identify long enriched regions in ChIP-seq datasets. Specifically, pertaining to MCF7 control samples we identified 5,911 segments with length of at least 4 Kbp (maximum 233,000 bp); and in MCF7 treated with E2 samples, we identified 6,200 such segments (maximum 325,000 bp). Conclusions We demonstrated the effectiveness of this method in studying binding patterns of PolII in cancer cells which enables further deep analysis in transcription regulation and epigenetics. Our method complements existing peak detection algorithms for ChIP-seq experiments. PMID:22536865

2012-01-01

46

Reduction of combustion by-products in WTE plants: O2 enrichment of underfire air in the MARTIN SYNCOM process.  

PubMed

The SYNCOM process involves oxygen enrichment of underfire air, recirculation of flue gas and a combustion control system using infrared thermography of the waste layer on the grate. At the demonstration plant in Coburg, operational reliability and plant availability using SYNCOM could be proven under real disposal conditions with a waste throughput of 7 t/h. Oxygen enrichment of the underfire air promotes the destruction of pollutants due to the high oxygen partial pressures and temperatures. This is then reflected in very low residual amounts of organic combustion by-products in the bottom ash and flue gas from the SYNCOM unit. The flue gas concentrations of organic pollutants are reduced, as compared with conventional operation, by over 35% (for CO, total hydrocarbons and PCDD/F) at the boiler outlet. As the flue gas flow is reduced by oxygen enrichment and flue gas recirculation, the resulting reduction in terms of kg of pollutant per Mg of waste is even higher. In the bottom ash, the level of organic residues is reduced, by 45% in the case of loss on ignition and by 55% in the case of TOC and dioxins (I-TE of PCDD/F). This is due to the higher oxygen partial pressures and the fuel bed temperature which is increased by 135 to 1200 degrees C. Other important features of the process include more intense sintering and thus improved immobilization of the bottom ash, as well as reduced flue gas and fly ash flows. PMID:11219678

Gohlke, O; Busch, M

2001-01-01

47

Process for producing enriched uranium having a .sup.235 U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage  

DOEpatents

An uranium enrichment process capable of producing an enriched uranium, having a .sup.235 U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower .sup.235 U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UF.sub.6 tails storage and sharply reduce fluorine use. The uranium enrichment process comprises feeding metallic uranium into an atomic vapor laser isotope separation process to produce an enriched metallic uranium isotopic mixture having a .sup.235 U content of at least about 2 wt. % and a metallic uranium residue containing from about 0.1 wt. % to about 0.2 wt. % .sup.235 U; fluorinating this enriched metallic uranium isotopic mixture to form UF.sub.6 ; processing the resultant isotopic mixture of UF.sub.6 in a gaseous diffusion process to produce a final enriched uranium product having a .sup.235 U content of at least 4 wt. %, and up to 93.5 wt. % or higher, of the total uranium content of the product, and a low .sup.235 U content UF.sub.6 having a .sup.235 U content of about 0.71 wt. % of the total uranium content of the low .sup.235 U content UF.sub.6 ; and converting this low .sup.235 U content UF.sub.6 to metallic uranium for recycle to the atomic vapor laser isotope separation process.

Horton, James A. (Livermore, CA); Hayden, Jr., Howard W. (Oakridge, TN)

1995-01-01

48

Process for producing enriched uranium having a {sup 235}U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage  

DOEpatents

An uranium enrichment process capable of producing an enriched uranium, having a {sup 235}U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower {sup 235}U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UF{sub 6} tails storage and sharply reduce fluorine use. The uranium enrichment process comprises feeding metallic uranium into an atomic vapor laser isotope separation process to produce an enriched metallic uranium isotopic mixture having a {sup 235} U content of at least about 2 wt. % and a metallic uranium residue containing from about 0.1 wt. % to about 0.2 wt. % {sup 235} U; fluorinating this enriched metallic uranium isotopic mixture to form UF{sub 6}; processing the resultant isotopic mixture of UF{sub 6} in a gaseous diffusion process to produce a final enriched uranium product having a {sup 235}U content of at least 4 wt. %, and up to 93.5 wt. % or higher, of the total uranium content of the product, and a low {sup 235}U content UF{sub 6} having a {sup 235}U content of about 0.71 wt. % of the total uranium content of the low {sup 235}U content UF{sub 6}; and converting this low {sup 235}U content UF{sub 6} to metallic uranium for recycle to the atomic vapor laser isotope separation process. 4 figs.

Horton, J.A.; Hayden, H.W. Jr.

1995-05-30

49

Process for producing enriched uranium having a ²³⁵U content of at least 4 wt. % via combination of a gaseous diffusion process and an atomic vapor laser isotope separation process to eliminate uranium hexafluoride tails storage  

Microsoft Academic Search

An uranium enrichment process capable of producing an enriched uranium, having a ²³⁵U content greater than about 4 wt. %, is disclosed which will consume less energy and produce metallic uranium tails having a lower ²³⁵U content than the tails normally produced in a gaseous diffusion separation process and, therefore, eliminate UFâ tails storage and sharply reduce fluorine use. The

J. A. Horton; H. W. Jr. Hayden

1995-01-01

50

Processing and properties of highly enriched double-wall carbon nanotubes.  

PubMed

Carbon nanotubes consist of one or more concentric graphene cylinders and are under investigation for a variety of applications that make use of their excellent thermal, mechanical, electronic and optical properties. Double-wall nanotubes are ideal systems for studying the interwall interactions influencing the properties of nanotubes with two or more walls. However, current techniques to synthesize double-wall nanotubes produce unwanted single- and multiwall nanotubes. Here, we show how density gradient ultracentrifugation can be used to separate double-wall nanotubes from mixtures of single- and multiwall nanotubes through differences in their buoyant density. This technique results in samples that are highly enriched in either single- or double-wall nanotubes of similar outer wall diameter, with the double-wall nanotubes being, on average, approximately 44% longer than the single-wall nanotubes. The longer average length of the double-wall nanotubes provides distinct advantages when they are used in transparent conductors. PMID:19119285

Green, Alexander A; Hersam, Mark C

2009-01-01

51

Simulation of a four-bed pressure swing adsorption process for oxygen enrichment  

Microsoft Academic Search

Pressure swing adsorption (PSA) is a cyclic process for gas purification and separation. More and more commercial separation processes employing PSA technology have been developed since the first patent of a PSA process in the US was described. This separation technology needs lower energy and is less costly than the conventional separation processes like absorption and distillation, and it can

Chengtung Chou; Wen-Chun Huang

1994-01-01

52

Real-time image processing for label-free enrichment of Actinobacteria cultivated in picolitre droplets.  

PubMed

The majority of today's antimicrobial therapeutics is derived from secondary metabolites produced by Actinobacteria. While it is generally assumed that less than 1% of Actinobacteria species from soil habitats have been cultivated so far, classic screening approaches fail to supply new substances, often due to limited throughput and frequent rediscovery of already known strains. To overcome these restrictions, we implement high-throughput cultivation of soil-derived Actinobacteria in microfluidic pL-droplets by generating more than 600,000 pure cultures per hour from a spore suspension that can subsequently be incubated for days to weeks. Moreover, we introduce triggered imaging with real-time image-based droplet classification as a novel universal method for pL-droplet sorting. Growth-dependent droplet sorting at frequencies above 100 Hz is performed for label-free enrichment and extraction of microcultures. The combination of both cultivation of Actinobacteria in pL-droplets and real-time detection of growing Actinobacteria has great potential in screening for yet unknown species as well as their undiscovered natural products. PMID:23881253

Zang, Emerson; Brandes, Susanne; Tovar, Miguel; Martin, Karin; Mech, Franziska; Horbert, Peter; Henkel, Thomas; Figge, Marc Thilo; Roth, Martin

2013-09-21

53

Enrichment of a Microbial Culture Capable of Reductive Debromination of the Flame Retardant Tetrabromobisphenol-A, and Identification of the Intermediate Metabolites Produced in the Process  

Microsoft Academic Search

Tetrabromobisphenol-A is a reactive flame retardant used in the production of many plastic polymers. In previous research, it was demonstrated that anaerobic microorganisms from contaminated sediment debrominate tetrabromobisphenol-A to bisphenol-A, but an enrichment culture was not established. The current study was carried out to identify the intermediate metabolites in this process and to determine the factors facilitating enrichment of debrominating

Ziv Arbeli; Zeev Ronen

2003-01-01

54

Galactic r-process enrichment by neutron star mergers in cosmological simulations of a Milky Way-mass galaxy  

NASA Astrophysics Data System (ADS)

We quantify the stellar abundances of neutron-rich r-process nuclei in cosmological zoom-in simulations of a Milky Way-mass galaxy from the Feedback In Realistic Environments project. The galaxy is enriched with r-process elements by binary neutron star (NS) mergers and with iron and other metals by supernovae. These calculations include key hydrodynamic mixing processes not present in standard semi-analytic chemical evolution models, such as galactic winds and hydrodynamic flows associated with structure formation. We explore a range of models for the rate and delay time of NS mergers, intended to roughly bracket the wide range of models consistent with current observational constraints. We show that NS mergers can produce [r-process/Fe] abundance ratios and scatter that appear reasonably consistent with observational constraints. At low metallicity, [Fe/H] ? -2, we predict there is a wide range of stellar r-process abundance ratios, with both supersolar and subsolar abundances. Low-metallicity stars or stars that are outliers in their r-process abundance ratios are, on average, formed at high redshift and located at large galactocentric radius. Because NS mergers are rare, our results are not fully converged with respect to resolution, particularly at low metallicity. However, the uncertain rate and delay time distribution of NS mergers introduce an uncertainty in the r-process abundances comparable to that due to finite numerical resolution. Overall, our results are consistent with NS mergers being the source of most of the r-process nuclei in the Universe.

van de Voort, Freeke; Quataert, Eliot; Hopkins, Philip F.; Kereš, Dušan; Faucher-Giguère, Claude-André

2015-02-01

55

Iodine in groundwater of the North China Plain: Spatial patterns and hydrogeochemical processes of enrichment  

E-print Network

Iodine in groundwater of the North China Plain: Spatial patterns and hydrogeochemical processes online xxxx Keywords: Iodine Groundwater Spatial patterns Hydrogeochemistry North China Plain The North China Plain (NCP), with an area of 139,238 km2 , has concurrent occurrence of high-iodine (>150 g

Zhan, Hongbin

56

Enrichment processes of arsenic in oxidic sedimentary rocks – From geochemical and genetic characterization to potential mobility  

Microsoft Academic Search

Sedimentary marine iron ores of Jurassic age and Tertiary marine sandy sediments containing iron hydroxides concretions have been sampled from boreholes and outcrops in two study areas in Germany to examine iron and arsenic accumulation processes. Samples were analyzed for bulk rock geochemistry (INAA\\/ICP-OES), quantitative mineralogy (XRD with Rietveld analysis), element distribution (electron microprobe) and arsenic fractionation (sequential extraction). Bulk

Andre Banning; Thomas R. Rüde

2010-01-01

57

NEW ABUNDANCE DETERMINATIONS OF CADMIUM, LUTETIUM, AND OSMIUM IN THE r-PROCESS ENRICHED STAR BD +17 3248 {sup ,}  

SciTech Connect

We report the detection of Cd I (Z = 48), Lu II (Z = 71), and Os II (Z = 76) in the metal-poor star BD +17 3248. These abundances are derived from an ultraviolet spectrum obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. This is the first detection of these neutron-capture species in a metal-poor star enriched by the r process. We supplement these measurements with new abundances of Mo I, Ru I, and Rh I derived from an optical spectrum obtained with the High Resolution Echelle Spectrograph on Keck. Combined with previous abundance derivations, 32 neutron-capture elements have been detected in BD +17 3248, the most complete neutron-capture abundance pattern in any metal-poor star to date. The light neutron-capture elements (38 {<=} Z {<=} 48) show a more pronounced even-odd effect than expected from current solar system r-process abundance predictions. The age for BD +17 3248 derived from the Th II/Os II chronometer is in better agreement with the age derived from other chronometers than the age derived from Th II/Os I. New Hf II abundance derivations from transitions in the ultraviolet are lower than those derived from transitions in the optical, and the lower Hf abundance is in better agreement with the scaled solar system r-process distribution.

Roederer, Ian U.; Sneden, Christopher [Department of Astronomy, University of Texas at Austin, 1 University Station, C1400 Austin, TX 78712-0259 (United States); Lawler, James E. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Cowan, John J. [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, Norman, OK 73019 (United States)], E-mail: iur@astro.as.utexas.edu

2010-05-01

58

A laboratory model of a prebiotic, spontaneous, and continuous enantiomeric enrichment process.  

PubMed

Construction and operation of a laboratory model, which combines the lately discovered enantioenrichment method of the author (2007) with the sun-powered evaporative pumping process of Hsu and Siegenthaler (Sedimentology 12:11-25 1969), is described. The model operated continuously for 120 days before it was intentionally shut down, even though it could have continued. During that time it raised the enantiomeric excess of the test material by a factor of 3.6. Implications of these results on the origin of biohomochirality are discussed. PMID:23344885

Goldberg, Stanley I

2013-02-01

59

New Abundance Determinations of Cadmium, Lutetium, and Osmium in the r-process Enriched Star BD+173248  

E-print Network

We report the detection of Cd I (Z = 48), Lu II (Z = 71), and Os II (Z = 76) in the metal-poor star BD+173248. These abundances are derived from an ultraviolet spectrum obtained with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope. This is the first detection of these neutron-capture species in a metal-poor star enriched by the r-process. We supplement these measurements with new abundances of Mo I, Ru I, and Rh I derived from an optical spectrum obtained with the High Resolution Echelle Spectrograph on Keck. Combined with previous abundance derivations, 32 neutron-capture elements have been detected in BD+173248, the most complete neutron-capture abundance pattern in any metal-poor star to date. The light neutron-capture elements (38 <= Z <= 48) show a more pronounced even-odd effect than expected from current Solar system r-process abundance predictions. The age for BD+173248 derived from the Th II/Os II chronometer is in better agreement with the age derived from other chronome...

Roederer, Ian U; Lawler, James E; Cowan, John J

2010-01-01

60

Code RED (Remediation and Enrichment Days): The Complex Journey of a School and University Partnership's Process to Increase Mathematics Achievement  

ERIC Educational Resources Information Center

This study examined a focused remediation and enrichment effort among school and university faculty to affect the mathematics achievement of a group of third-grade students in a Title I elementary school. A total of 87 students participated in the Code RED (Remediation and Enrichment Days) Project. During the Code RED Project, student assessment…

Moyer, Patricia S.; Dockery, Kim; Jamieson, Spencer; Ross, Julie

2007-01-01

61

The lead discrepancy in intrinsically s-process enriched post-AGB stars in the Magellanic Clouds  

NASA Astrophysics Data System (ADS)

Context. Our understanding of the s-process nucleosynthesis in asymptotic giant branch (AGB) stars is incomplete. AGB models predict, for example, large overabundances of lead (Pb) compared to other s-process elements in metal-poor low-mass AGB stars. This is indeed observed in some extrinsically enhanced metal-poor stars, but not in all. An extensive study of intrinsically s-process enriched objects is essential for improving our knowledge of the AGB third dredge-up and associated s-process nucleosynthesis. Aims: We compare the spectral abundance analysis of the SMC post-AGB star J004441.04-732136.4 with state-of-the-art AGB model predictions with a main focus on Pb. The low signal-to-noise (S/N) in the Pb line region made the result of our previous study inconclusive. We acquired additional data covering the region of the strongest Pb line. Methods: By carefully complementing re-reduced previous data, with newly acquired UVES optical spectra, we improve the S/N of the spectrum around the strongest Pb line. Therefore, an upper limit for the Pb abundance is estimated from a merged weighted mean spectrum using synthetic spectral modeling. We then compare the abundance results from the combined spectra to predictions of tailored AGB evolutionary models from two independent evolution codes. In addition, we determine upper limits for Pb abundances for three previously studied LMC post-AGB objects. Results: Although theoretical predictions for J004441.04-732136.4 match the s-process distribution up to tungsten (W), the predicted very high Pb abundance is clearly not detected. The three additional LMC post-AGB stars show a similar lack of a very high Pb abundance. Conclusions: From our study, we conclude that none of these low-mass, low-metallicity post-AGB stars of the LMC and SMC are strong Pb producers. This conflicts with current theoretical predictions. Based on observations collected with the Very Large Telescope at the ESO Paranal Observatory (Chili) of programme number 084.D-0932 and 088.D-0433.

De Smedt, K.; Van Winckel, H.; Kamath, D.; Karakas, A. I.; Siess, L.; Goriely, S.; Wood, P.

2014-03-01

62

Effects of future climate change, CO2 enrichment, and vegetation structure variation on hydrological processes in China  

USGS Publications Warehouse

Investigating the relationship between factors (climate change, atmospheric CO2 concentrations enrichment, and vegetation structure) and hydrological processes is important for understanding and predicting the interaction between the hydrosphere and biosphere. The Integrated Biosphere Simulator (IBIS) was used to evaluate the effects of climate change, rising CO2, and vegetation structure on hydrological processes in China at the end of the 21st century. Seven simulations were implemented using the assemblage of the IPCC climate and CO2 concentration scenarios, SRES A2 and SRES B1. Analysis results suggest that (1) climate change will have increasing effects on runoff, evapotranspiration (ET), transpiration (T), and transpiration ratio (transpiration/evapotranspiration, T/E) in most hydrological regions of China except in the southernmost regions; (2) elevated CO2 concentrations will have increasing effects on runoff at the national scale, but at the hydrological region scale, the physiology effects induced by elevated CO2 concentration will depend on the vegetation types, climate conditions, and geographical background information with noticeable decreasing effects shown in the arid Inland region of China; (3) leaf area index (LAI) compensation effect and stomatal closure effect are the dominant factors on runoff in the arid Inland region and southern moist hydrological regions, respectively; (4) the magnitudes of climate change (especially the changing precipitation pattern) effects on the water cycle are much larger than those of the elevated CO2 concentration effects; however, increasing CO2 concentration will be one of the most important modifiers to the water cycle; (5) the water resource condition will be improved in northern China but depressed in southernmost China under the IPCC climate change scenarios, SRES A2 and SRES B1.

Zhu, Qiuan; Jiang, Hong; Peng, Changhui; Liu, Jinxun; Fang, Xiuqin; Wei, Xiaohua; Liu, Shirong; Zhou, Guomo

2012-01-01

63

Processing, physico-chemical, sensory and nutritional evaluation of protein, mineral and vitamin enriched peanut chikki - an Indian traditional sweet  

Microsoft Academic Search

Chikki, a popular Indian traditional sweet snack prepared from peanut was enriched with protein, minerals and vitamins by incorporating\\u000a soy protein isolate, calcium carbonate, ferrous fumerate, vitamin A and folic acid to meet the growing demand for health foods.\\u000a The enriched nutra chikki was evaluated for physico-chemical characteristics such as moisture, texture, peroxide value (PV), fatty acid composition\\u000a in comparison

Byrappa Vasu Pallavi; Ramakrishna Chetana; Sunkireddy Yella Reddy

64

Detailed abundance study of four s-process enriched post-AGB stars in the Large Magellanic Cloud  

NASA Astrophysics Data System (ADS)

Context. The photospheric abundances of evolved solar-type stars of different metallicities serve as probes into stellar evolution theory. Aims: Stellar photospheres of post-asymptotic giant branch (post-AGB) stars bear witness to the internal chemical enrichment processes, integrated over their entire stellar evolution. Here we study post-AGB stars in the Large Magellanic Cloud (LMC). With their known distances, these rare objects are ideal tracers of AGB nucleosynthesis and dredge-up phenomena. Methods: We used the UVES spectrograph mounted on the Very Large Telescope at the European Southern Observatory, to obtain high-resolution spectra with high signal-to-noise of a sample of four post-AGB stars. The objects display a spectral energy distribution that indicates the presence of circumstellar dust. We perform a detailed abundance analysis on the basis of these spectra. Results: All objects are C-rich, and strongly enhanced in s-process elements. We deduced abundances of heavy s-process elements for all stars in the sample, and even found an indication of the presence of Hg in the spectrum of one object. The metallicity of all stars except J053253.51-695915.1 is considerably lower than the average value that is observed for the LMC. The derived luminosities show that we witness the late evolution of low-mass stars with initial masses close to 1 M?. An exception is J053253.51-695915.1 and we argue that this object is likely a binary. Conclusions: We confirmed the correlation between the efficiency of the third-dredge up and the neutron exposure that is detected in Galactic post-AGB stars. The non-existence of a correlation between metallicity and neutron irradiation is also confirmed and expanded to smaller metallicities. We confirm the status of 21 ?m stars as post-carbon stars. Current theoretical AGB models overestimate the observed C/O ratios and fail to reproduce the variety of s-process abundance patterns that is observed in otherwise very similar objects. Similar results have recently been found for a post-AGB star in the Small Magellanic Cloud (SMC). Based on observations collected with the Very Large Telescope at the ESO Paranal Observatory (Chili) of programme number 082.D-0941.Detailed line data used for the abundance analysis are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/554/A106

van Aarle, E.; Van Winckel, H.; De Smedt, K.; Kamath, D.; Wood, P. R.

2013-06-01

65

Enriching distinctive microbial communities from marine sediments via an electrochemical-sulfide-oxidizing process on carbon electrodes  

PubMed Central

Sulfide is a common product of marine anaerobic respiration, and a potent reactant biologically and geochemically. Here we demonstrate the impact on microbial communities with the removal of sulfide via electrochemical methods. The use of differential pulse voltammetry revealed that the oxidation of soluble sulfide was seen at +30 mV (vs. SHE) at all pH ranges tested (from pH = 4 to 8), while non-ionized sulfide, which dominated at pH = 4 was poorly oxidized via this process. Two mixed cultures (CAT and LA) were enriched from two different marine sediments (from Catalina Island, CAT; from the Port of Los Angeles, LA) in serum bottles using a seawater medium supplemented with lactate, sulfate, and yeast extract, to obtain abundant biomass. Both CAT and LA cultures were inoculated in electrochemical cells (using yeast-extract-free seawater medium as an electrolyte) equipped with carbon-felt electrodes. In both cases, when potentials of +630 or +130 mV (vs. SHE) were applied, currents were consistently higher at +630 then at +130 mV, indicating more sulfide being oxidized at the higher potential. In addition, higher organic-acid and sulfate conversion rates were found at +630 mV with CAT, while no significant differences were found with LA at different potentials. The results of microbial-community analyses revealed a decrease in diversity for both CAT and LA after electrochemical incubation. In addition, some bacteria (e.g., Clostridium and Arcobacter) not well-known to be capable of extracellular electron transfer, were found to be dominant in the electrochemical cells. Thus, even though the different mixed cultures have different tolerances for sulfide, electrochemical-sulfide removal can lead to major population changes. PMID:25741331

Li, Shiue-Lin; Nealson, Kenneth H.

2015-01-01

66

16. VIEW OF THE ENRICHED URANIUM RECOVERY SYSTEM. ENRICHED URANIUM ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

16. VIEW OF THE ENRICHED URANIUM RECOVERY SYSTEM. ENRICHED URANIUM RECOVERY PROCESSED RELATIVELY PURE MATERIALS AND SOLUTIONS AND SOLID RESIDUES WITH RELATIVELY LOW URANIUM CONTENT. URANIUM RECOVERY INVOLVED BOTH SLOW AND FAST PROCESSES. (4/4/66) - Rocky Flats Plant, General Manufacturing, Support, Records-Central Computing, Southern portion of Plant, Golden, Jefferson County, CO

67

Profile of World Uranium Enrichment Programs - 2007  

Microsoft Academic Search

It is generally agreed that the most difficult step in building a nuclear weapon is acquiring weapons grade fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, while HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium

Laughter; Mark D

2007-01-01

68

Profile of World Uranium Enrichment Programs-2009  

Microsoft Academic Search

It is generally agreed that the most difficult step in building a nuclear weapon is acquiring fissile material, either plutonium or highly enriched uranium (HEU). Plutonium is produced in a nuclear reactor, whereas HEU is produced using a uranium enrichment process. Enrichment is also an important step in the civil nuclear fuel cycle, in producing low enriched uranium (LEU) for

Laughter; Mark D

2009-01-01

69

Enriched Uranium  

NSDL National Science Digital Library

This Wikipedia website provides information about the various concentrations of uranium used for different applications. Topics include a brief description of the grades of uranium and methods of isotope separation. There are also links to other aspects of uranium enrichment and related information. This information lays the foundation for informed discussion about the potential of nuclear energy and the risks of nuclear proliferation.

Wikipedia

70

Project ENRICH.  

ERIC Educational Resources Information Center

Project ENRICH was conceived in Beaver County, Pennsylvania, to: (1) identify preschool children with learning disabilities, and (2) to develop a program geared to the remediation of the learning disabilities within a school year, while allowing the child to be enrolled in a regular class situation for the following school year. Through…

Gwaley, Elizabeth; And Others

71

Enrichment of Rare Earth Elements during magmatic and post-magmatic processes: a case study from the Loch Loyal Syenite Complex, northern Scotland  

NASA Astrophysics Data System (ADS)

Concern about security of supply of critical elements used in new technologies, such as the Rare Earth Elements (REE), means that it is increasingly important to understand the processes by which they are enriched in crustal settings. High REE contents are found in syenite-dominated alkaline complexes intruded along the Moine Thrust Zone, a major collisional zone in north-west Scotland. The most northerly of these is the Loch Loyal Syenite Complex, which comprises three separate intrusions. One of these, the Cnoc nan Cuilean intrusion, contains two mappable zones: a Mixed Syenite Zone in which mafic melasyenite is mixed and mingled with leucosyenite and a Massive Leucosyenite Zone. Within the Mixed Syenite Zone, hydrothermal activity is evident in the form of narrow altered veins dominated by biotite and magnetite; these are poorly exposed and their lateral extent is uncertain. The REE mineral allanite is relatively abundant in the melasyenite and is extremely enriched in the biotite-magnetite veins, which have up to 2 % total rare earth oxides in bulk rock analyses. An overall model for development of this intrusion can be divided into three episodes: (1) generation of a Light Rare Earth Element (LREE)-enriched parental magma due to enrichment of the mantle source by subduction of pelagic carbonates; (2) early crystallisation of allanite in melasyenite, due to the saturation of the magma in the LREE; and (3) hydrothermal alteration, in three different episodes identified by petrography and mineral chemistry, generating the intense enrichment of REE in the biotite-magnetite veins. Dating of allanite and titanite in the biotite-magnetite veins gives ages of c. 426 Ma, overlapping with previously published crystallisation ages for zircon in the syenite.

Walters, A. S.; Goodenough, K. M.; Hughes, H. S. R.; Roberts, N. M. W.; Gunn, A. G.; Rushton, J.; Lacinska, A.

2013-10-01

72

Final report on the project entitled: Highly Preheated Combustion Air System with/without Oxygen Enrichment for Metal Processing Furnaces  

SciTech Connect

This work develops and demonstrates a laboratory-scale high temperature natural gas furnace that can operate with/without oxygen enrichment to significantly improve energy efficiency and reduce emissions. The laboratory-scale is 5ft in diameter & 8ft tall. This furnace was constructed and tested. This report demonstrates the efficiency and pollutant prevention capabilities of this test furnace. The project also developed optical detection technology to control the furnace output.

Arvind Atreya

2007-02-16

73

Synergistic effects of long-term antioxidant diet and behavioral enrichment on beta-amyloid load and non-amyloidogenic processing in aged canines.  

PubMed

A long-term intervention (2.69 years) with an antioxidant diet, behavioral enrichment, or the combined treatment preserved and improved cognitive function in aged canines. Although each intervention alone provided cognitive benefits, the combination treatment was additive. We evaluate the hypothesis that antioxidants, enrichment, or the combination intervention reduces age-related beta-amyloid (Abeta) neuropathology, as one mechanism mediating observed functional improvements. Measures assessed were Abeta neuropathology in plaques, biochemically extractable Abeta(40) and Abeta(42) species, soluble oligomeric forms of Abeta, and various proteins in the beta-amyloid precursor protein (APP) processing pathway. The strongest and most consistent effects on Abeta pathology were observed in animals receiving the combined antioxidant and enrichment treatment. Specifically, Abeta plaque load was significantly decreased in several brain regions, soluble Abeta(42) was decreased selectively in the frontal cortex, and a trend for lower Abeta oligomer levels was found in the parietal cortex. Reductions in Abeta may be related to shifted APP processing toward the non-amyloidogenic pathway, because alpha-secretase enzymatic activity was increased in the absence of changes in beta-secretase activity. Although enrichment alone had no significant effects on Abeta, reduced Abeta load and plaque maturation occurred in animals receiving antioxidants as a component of treatment. Abeta measures did not correlate with cognitive performance on any of the six tasks assessed, suggesting that modulation of Abeta alone may be a relatively minor mechanism mediating cognitive benefits of the interventions. Overall, the data indicate that multidomain treatments may be a valuable intervention strategy to reduce neuropathology and improve cognitive function in humans. PMID:20660265

Pop, Viorela; Head, Elizabeth; Hill, Mary-Ann; Gillen, Dan; Berchtold, Nicole C; Muggenburg, Bruce A; Milgram, Norton W; Murphy, M Paul; Cotman, Carl W

2010-07-21

74

Synergistic effects of long-term antioxidant diet and behavioral enrichment on beta-amyloid load and non-amyloidogenic processing in aged canines  

PubMed Central

A long-term intervention (2.69 years) with an antioxidant diet, behavioral enrichment, or the combined treatment preserved and improved cognitive function in aged canines. While each intervention alone provided cognitive benefits, the combination treatment was additive. We evaluate the hypothesis that antioxidants, enrichment, or the combination intervention reduces age-related beta-amyloid (A?) neuropathology, as one mechanism mediating observed functional improvements. Measures assessed were A? neuropathology in plaques, biochemically extractable A?40 and A?42 species, soluble oligomeric forms of A?, and various proteins in the beta-amyloid precursor protein (APP) processing pathway. The strongest and most consistent effects on A? pathology were observed in animals receiving the combined antioxidant and enrichment treatment. Specifically, A? plaque load was significantly decreased in several brain regions, soluble A?42 was decreased selectively in the frontal cortex, and a trend for lower A? oligomer levels was found in the parietal cortex. Reductions in A? may be related to shifted APP processing towards the non-amyloidogenic pathway, as alpha-secretase enzymatic activity was increased, in the absence of changes in beta-secretase activity. While enrichment alone had no significant effects on A?, reduced A? load and plaque maturation occurred in animals receiving antioxidants as a component of treatment. AB measures did not correlate with cognitive performance on any of the 6 tasks assessed, suggesting that modulation of AB alone may be a relatively minor mechanism mediating cognitive benefits of the interventions. Overall, the data indicate that multi-domain treatments may be a valuable intervention strategy to reduce neuropathology and improve cognitive function in humans. PMID:20660265

Pop, Viorela; Head, Elizabeth; Hill, Mary-Ann; Gillen, Dan; Berchtold, Nicole C.; Muggenburg, Bruce.A.; Milgram, Norton W.; Murphy, M. Paul; Cotman, Carl W.

2013-01-01

75

Réponses saisonnières du phytoplancton aux rapports d'enrichissements N:Si:P dans la lagune de Bizerte (Sud-Ouest de la Méditerranée)  

Microsoft Academic Search

This study investigated the role of N, P and Si enrichments on phytoplankton in the Bizerte Lagoon (southwestern Mediterranean Sea, Tunisia) during March, June, August, October and December 2004. Polycarbonate bottles were enriched with different nutrients according to four treatments N:Si:P ratios [+NSi\\/?P (40:40:1), +P\\/?NSi (20:20:2,5), +NP\\/?Si (16:0:1) and +Si\\/?NP (16:32:1)] and incubated in situ during six days. Chl?a and

Mohamed Ali Chikhaoui; Asma Sakka Hlaili; Hassine Hadj Mabrouk

2008-01-01

76

Conversion of Methane to Hydrogen in a Reversible Flow Reactor in the Process of Filtration Combustion of Fuel Mixtures Enriched with Oxygen  

NASA Astrophysics Data System (ADS)

This paper considers the process of partial oxidation of methane to syngas in a reversible flow reactor in the process of filtration combustion of fuel mixtures enriched with oxygen in an inert porous medium. Experimental studies have been made of the influence of the volume concentration of oxygen in the initial fuel mixture on the basic parameters of the conversion process — the maximum temperature in the combustion wave and the composition of reaction products. Investigations have been carried out for fuel mixtures having different calorific values under the same filtration conditions. It has been shown that the addition of oxygen to the initial methane-air mixture permits increasing considerably the efficiency of the conversion process.

Dmitrenko, Yu. M.; Klyovan, R. A.

2013-11-01

77

Incidence of Campylobacter from Post-chill Poultry Carcass Rinse Samples by Improved Enrichment Methodologies from a Processing Plant over a Three Day Sampling Period  

Technology Transfer Automated Retrieval System (TEKTRAN)

Introduction: Numerous studies have been conducted to improve enrichment procedures to recover injured or stressed Campylobacter cells. Recent studies have shown that utilizing TECRA enrichment broth and modifying the standard procedure can increase the number of positive poultry rinse samples. ...

78

The effects of inquiry-based summer enrichment activities on rising eighth graders' knowledge of science processes, attitude toward science, and perceptions of scientists  

NASA Astrophysics Data System (ADS)

The purpose of this research was to examine the effects of summer science enrichment on eighth-graders' science process skills knowledge, attitude toward science and perceptions of scientists. A single group pre- and post-test design was used to test participants in a summer science enrichment camp, which took place over a three-week period in the summer of 2000. Participants, all of whom were residents of the Mississippi area known as the Delta, lived on the campus of Mississippi Valley State University for the entire course of the camp. Activities included several guided inquiry-based projects such as water rocket design and solar or battery-powered car design. Participants also took trips to an environmental camp in north Mississippi and to the Stennis Space Center on the Mississippi Gulf Coast. Participants worked on their projects in groups, supervised by an undergraduate student "mentor". Participants were encouraged to keep journals of their experiences throughout the camp, and the researcher developed a rubric to evaluate student journals for process knowledge, evidence of planning, reflective thought, and disposition toward science. Tests were used to evaluate student knowledge of process skills, attitude toward science, and perceptions of scientists. On the Test of Integrated Process Skills (Dillashaw & Okey, 1983), the students showed significant improvement overall, but when evaluated separately, males showed significant improvement while females did not. On the Attitude toward Science in School Assessment (Germane, 1988), data indicated that attitude toward science improved significantly for the group as a whole, but upon closer inspection, indicated a significant improvement for the female students only. On Chamber's Draw-a-Scientist Test (1983), analysis of student drawings indicated no significant change in stereotypical images of scientists for the group overall. However, boys' scores indicated a significant improvement when analyzed separately. Journal analysis revealed a need for instruction in their use, but provided an interesting glimpse into students' thoughts. The researcher concluded that summer enrichment camps have potential m terms of helping students improve their science knowledge and their thinking about science. Further research on summer opportunities, inquiry-based instruction, work with mentors, and use of journals is suggested by this work.

Moore, Juanita Martin

79

Ultrathin (5 nm) SiGe-On-Insulator with high compressive strain (-2 GPa): From fabrication (Ge enrichment process) to in-depth characterizations  

NASA Astrophysics Data System (ADS)

300 mm ultrathin Silicon-On-Insulator (SOI) wafers with SiGe/Si stacks on top were used as pre-structures for the fabrication of 5 nm thick SiGe-On-Insulator (SGOI) substrates obtained by the Ge enrichment technique. Those substrates will be used as the channel of advanced Fully Depleted (FD) p-type Metal Oxide Semiconductor Field Effect Transistors (pMOSFET). We present in the first part the successful fabrication of 5 nm SGOI wafers. Various characterization techniques are used to investigate the Ge profile and the final strain in the fabricated 5 nm Si0.7Ge0.3 film. Secondary Ions Mass Spectrometry (SIMS) and Scanning Transmission Electron Microscopy (STEM) clearly show that the Ge content is very homogeneous (xGe = 30 ± 1%) in the SiGe layer. Raman spectroscopy and High Angle Annular Dark Field (HAADF) STEM both confirm that the 5 nm thick SiGe film is compressively strained (-2 GPa). The second part is dedicated to the sensitivity of the Ge enrichment process (based on numerical modelling). We investigate the impact of single and combined fluctuations of the pre-structure parameters (TSi, TSiGe,0, xGe,0) on the final SiGe layer (TSiGe, xGe).

Glowacki, F.; Le Royer, C.; Morand, Y.; Pédini, J.-M.; Denneulin, T.; Cooper, D.; Barnes, J.-P.; Nguyen, P.; Rouchon, D.; Hartmann, J.-M.; Gourhant, O.; Baylac, E.; Campidelli, Y.; Barge, D.; Bonnin, O.; Schwarzenbach, W.

2014-07-01

80

Preliminary study of sources and processes of enrichment of manganese in water from University of Rhode Island supply wells  

USGS Publications Warehouse

Concentrations of dissolved manganese have increased from 0.0 to as much as 3.3 mg/liter over a period of years in closely spaced University of Rhode Island supply wells. The wells tap stratified glacial deposits and derive part of their water from infiltration from a nearby river-pond system. The principal sources of the manganese seem to be coatings of oxides and other forms of manganese on granular aquifer materials and organic-rich sediments on the bottom of the pond and river. Chemical analyses of water from an observation well screened from 3 to 5 feet below the pond bottom indicate that infiltration of water through organic-rich sediments on the pond bottom is the likely cause of manganese enrichment in the well supplies. After passing through the organic layer, the water contains concentrations of manganese as high as 1.2 mg/liter. Manganese in water in concentrations that do not cause unpleasant taste is not regarded to be toxicologically significant. However, concentrations in excess of a few tenths of a milligram per liter are undesirable in public supplies and in many industrial supplies. Brown and others (21970) note that waters containing manganese in concentrations less than 0.1 mg/liter seldom prove troublesome, but that those containing more than 0.5 mg/liter may form objectionable deposits on cooked food, laundry, and plumbing fixtures. The U.S. Public health Service (1962) recommends that the concentrations of manganese in drinking and culinary water not exceed 0.05 mg/liter. (Woodard-USGS)

Silvey, William Dudley; Johnston, Herbert E.

1977-01-01

81

Apolipoprotein E-e4, processing speed, and white matter volume in a genetically enriched sample of midlife adults.  

PubMed

Healthy midlife children of a parent with Alzheimer's disease ([AD] N = 23; 9 male) participated in neuropsychological testing, and magnetic resonance imaging (MRI) of brain volumetrics were obtained. In all, 35% of the sample were apolipoprotein E (ApoE)-e4 positive (n = 8; 5 male). The ApoE-e4 group exhibited significantly slower performances on an executive function and processing speed measure and had less white matter volume than the non-ApoE-e4 group. Lesser white matter volume was significantly correlated with slower processing speed. Processing speed and changes in white matter volume might be indicators of preclinical decline in AD. PMID:21937476

Ready, Rebecca E; Baran, B; Chaudhry, M; Schatz, K; Gordon, J; Spencer, R M C

2011-09-01

82

Effet d'un enrichissement en nickel sur la stabilite mecanique de l'austenite de reversion lorsque soumise a de la fatigue oligocyclique  

NASA Astrophysics Data System (ADS)

The effect of nickel enrichment on the mechanical stability of the reversed austenite contained in martensitic stainless steels 13%Cr-4%Ni and 13%Cr-6%Ni was investigated. The main objective of the study was to observe their microstructure and to compare the dynamic behaviour of the reversed austenite. Tempers made at different temperatures showed that the 6% Ni alloy began to form more austenite and at a lower temperature. SEM and TEM analysis were used to see the austenite and measure its chemical composition. It has been observed that it was richer in Ni than the surrounding martensite. This enrichment increased with tempering temperature and caused an impoverishment of the surrounding martensite. The study also showed that the chemical composition of the austenite formed at the peak (maximum) of both alloys was similar. For a same tempering, this suggests Ni can help to form more austenite but this austenite is not necessarily richer in Ni. The analysis also showed that the austenite was predominantly lamellar and located at the interface and/or inside the martensite laths. Low cycle fatigue tests have shown that the austenite of the 6% Ni alloy was the most mechanically stable even if its Ni content was lower than the 4% Ni alloy austenite. This behaviour was explained by a thinner and narrower morphology of this phase. For a different content of Ni and different quantity of austenite, the most mechanically stable one was in the 4% Ni alloy. It turned out that its reversed austenite was thinner and its surrounding martensite was a bit harder than the 6% Ni alloy austenite. The effect of Ni enrichment of an alloy would be beneficial regarding the mechanical stability if a suitable tempering is made. This tempering must form a thin lamellar austenite in a sufficiently hard martensite. More Ni in the austenite would not necessarily raise the mechanical stability. It could contribute but it seems that it is not be the main factor governing the mechanical stability of the reversed austenite.

Godin, Stephane

83

Influence of fine process particles enriched with metals and metalloids on Lactuca sativa L. leaf fatty acid composition following air and/or soil-plant field exposure.  

PubMed

We investigate the effect of both foliar and root uptake of a mixture of metal(loid)s on the fatty acid composition of plant leaves. Our objectives are to determine whether both contamination pathways have a similar effect and whether they interact. Lactuca sativa L. were exposed to fine process particles enriched with metal(loid)s in an industrial area. Data from a first experiment were used to conduct an exploratory statistical analysis which findings were successfully cross-validated by using the data from a second one. Both foliar and root pathways impact plant leaf fatty acid composition and do not interact. Z index (dimensionless quantity), weighted product of fatty acid concentration ratios was built up from the statistical analyses. It provides new insights on the mechanisms involved in metal uptake and phytotoxicity. Plant leaf fatty acid composition is a robust and fruitful approach to detect and understand the effects of metal(loid) contamination on plants. PMID:23694728

Schreck, Eva; Laplanche, Christophe; Le Guédard, Marina; Bessoule, Jean-Jacques; Austruy, Annabelle; Xiong, Tiantian; Foucault, Yann; Dumat, Camille

2013-08-01

84

Chromatin enrichment for proteomics  

PubMed Central

During interphase, chromatin hosts fundamental cellular processes, such as gene expression, DNA replication and DNA damage repair. To analyze chromatin on a proteomic scale, we have developed chromatin enrichment for proteomics (ChEP), which is a simple biochemical procedure that enriches interphase chromatin in all its complexity. It enables researchers to take a ‘snapshot’ of chromatin and to isolate and identify even transiently bound factors. In ChEP, cells are fixed with formaldehyde; subsequently, DNA together with all cross-linked proteins is isolated by centrifugation under denaturing conditions. This approach enables the analysis of global chromatin composition and its changes, which is in contrast with existing chromatin enrichment procedures, which either focus on specific chromatin loci (e.g., affinity purification) or are limited in specificity, such as the analysis of the chromatin pellet (i.e., analysis of all insoluble nuclear material). ChEP takes half a day to complete and requires no specialized laboratory skills or equipment. ChEP enables the characterization of chromatin response to drug treatment or physiological processes. Beyond proteomics, ChEP may preclear chromatin for chromatin immunoprecipitation (ChIP) analyses. PMID:25101823

Kustatscher, Georg; Wills, Karen L. H.; Furlan, Cristina; Rappsilber, Juri

2015-01-01

85

Mineralogical and geochemical characteristics of a serpentinite-derived laterite profile from East Sulawesi, Indonesia: Implications for the lateritization process and Ni supergene enrichment in the tropical rainforest  

NASA Astrophysics Data System (ADS)

To evaluate the lateritization process and supergene Ni enrichment in the tropical rainforest, a well developed laterite profile over the serpentinite in the Kolonodale area of East Sulawesi, Indonesia, has been investigated using field geology methods, mineralogical and geochemical techniques. Three lithostratigraphic horizons over the bedrock are distinguished from bottom to top: the saprolite horizon, the limonite horizon, and the ferruginous cap. In general, the profile is characterized by (1) a depth-related pH ranging from 5.56 to 8.56, with a higher value in the saprolite horizon and a lower value in the ferruginous cap, (2) a highly variable organic matter concentration from 1.11% to 4.82%, showing a increasing trend from bottom to top, (3) a progressive mineral assemblage transition from the silicate mineral dominant (mainly serpentine) to the Fe-oxyhydroxide dominant (mainly goethite), and (4) a typical laterite geochemical pattern with an increase of Fe, Al, Mn, Cr and Ti but a decrease of Mg, Ca, Na and K upward from the bedrock. The highest concentration of Ni (up to 11.53%NiO) occurs in the saprolite horizon, showing nearly 40 times richer compared to the bedrock. The mineral evolution during the lateritization process shows various paths from the primary minerals to altered minerals, which is integrally affected by the nature of the primary minerals and environmental conditions. Garnierite, as a significant ore mineral formed by the secondary precipitation processes in the study profile, is identified as a mixture of talc- and serpentine-like phases. The mass-balance calculation reveals that there are diversified elemental behaviors during the serpentinite lateritization under the rainforest conditions. In particular, Ni, as the ore-forming element in the laterite profile, is associated closely with the pH environment, organic matter concentration and mineral evolution during the lateritization process. The findings of the present study support a four-stage evolutional model for the lateritization process: the ferruginous saprolite development (stage I), the limonite development (stage II), the silicate saprolite and ferruginous cap development (stage III), and the precipitation of secondary minerals (stage IV). Due to this multistage process, there is a progressive Ni-enrichment in the laterite profile.

Fu, Wei; Yang, Jianwen; Yang, Mengli; Pang, Baocheng; Liu, Xijun; Niu, Hujie; Huang, Xiaorong

2014-10-01

86

Effect of prior growth temperature, type of enrichment medium, and temperature and time of storage on recovery of Listeria monocytogenes following high pressure processing of milk.  

PubMed

A five-isolate cocktail of Listeria monocytogenes (10(3) cfu/ml in skim or whole raw milk) was subjected to 450 MPa for 900 s or 600 MPa for 90 s. The effects of prior growth temperature, type of milk (skim vs. whole), type of recovery-enrichment media (optimized Penn State University [oPSU] broth, Listeria Enrichment Broth [LEB], Buffered LEB [BLEB], Modified BLEB [MBLEB], and milk), storage temperature and storage time on the recovery of L. monocytogenes were examined. Optimized PSU broth significantly increased the recovery of L. monocytogenes following high pressure processing (HPP), and was 63 times more likely to recover L. monocytogenes following HPP, compared to LEB, BLEB and MBLEB broths (p<0.05; Odds Ratio=63.09, C.I. 23.70-167.96). There was a significant main effect for prior growth temperature (p<0.05). However, this relationship could not be interpreted given the significant interaction effects between temperature and both pressure and milk type. HPP-injured L. monocytogenes could be recovered using both LEB and oPSU broths after storage of milk at 4, 15 and 30 degrees C, with recovery being maximal after 24 to 72 h of storage; however, recovery yield dropped to 0% after prolonged storage of milk at 4 and 30 degrees C. In contrast, storage of milk at 15 degrees C yielded the most rapid rate of recovery and the highest recovery yield (100%), which remained high throughout the 14 days of storage at 15 degrees C. The above factors need to be taken into consideration when designing challenge studies to insure complete inactivation of L. monocytogenes and possibly other foodborne pathogens during high pressure processing of foods. PMID:15878406

Bull, Michelle K; Hayman, Melinda M; Stewart, Cynthia M; Szabo, Elizabeth A; Knabel, Stephen J

2005-05-01

87

New generation enrichment monitoring technology for gas centrifuge enrichment plants  

SciTech Connect

The continuous enrichment monitor, developed and fielded in the 1990s by the International Atomic Energy Agency, provided a go-no-go capability to distinguish between UF{sub 6} containing low enriched (approximately 4% {sup 235}U) and highly enriched (above 20% {sup 235}U) uranium. This instrument used the 22-keV line from a {sup 109}Cd source as a transmission source to achieve a high sensitivity to the UF{sub 6} gas absorption. The 1.27-yr half-life required that the source be periodically replaced and the instrument recalibrated. The instrument's functionality and accuracy were limited by the fact that measured gas density and gas pressure were treated as confidential facility information. The modern safeguarding of a gas centrifuge enrichment plant producing low-enriched UF{sub 6} product aims toward a more quantitative flow and enrichment monitoring concept that sets new standards for accuracy stability, and confidence. An instrument must be accurate enough to detect the diversion of a significant quantity of material, have virtually zero false alarms, and protect the operator's proprietary process information. We discuss a new concept for advanced gas enrichment assay measurement technology. This design concept eliminates the need for the periodic replacement of a radioactive source as well as the need for maintenance by experts. Some initial experimental results will be presented.

Ianakiev, Kiril D [Los Alamos National Laboratory; Alexandrov, Boian S. [Los Alamos National Laboratory; Boyer, Brian D. [Los Alamos National Laboratory; Hill, Thomas R. [Los Alamos National Laboratory; Macarthur, Duncan W. [Los Alamos National Laboratory; Marks, Thomas [Los Alamos National Laboratory; Moss, Calvin E. [Los Alamos National Laboratory; Sheppard, Gregory A. [Los Alamos National Laboratory; Swinhoe, Martyn T. [Los Alamos National Laboratory

2008-06-13

88

Effects of dietary enrichment with n-3 fatty acids on the quality of raw and processed breast meat of high and low growth rate chickens.  

PubMed

1. The enrichment of raw poultry meat with n-3 fatty acids (n-3 FA) has been investigated in detail, particularly in high growth rate genotype standard broiler chickens, whereas low growth rate genotype Label Rouge chickens have received less attention. With the increased development of processed poultry products, it is necessary to ensure that the nutritional and sensory quality of meat enriched with n-3 FA is not affected by processing. 2. Two experiments were undertaken for this purpose. In the first experiment, 696 male Ross 708 chickens were reared under standard conditions, and in the second, 750 male JA 657 chickens were reared under Label Rouge conditions. All birds received the same starting and growing diets containing palm and soya oils in each experiment. Birds were distributed into three groups from 21 or 57 d of age for standard and Label Rouge chickens, respectively, and given a control, linseed oil or extruded linseed diet. Diets were also supplemented with vitamin E (100-200 mg/kg). Birds were slaughtered at 56 or 84 d of age for standard and Label Rouge chickens, respectively. A total amount of 60 kg of breast meat from each group was processed into white cured-cooked meat. 3. The dietary treatment had no effect on the growth performance of chickens or meat yield. The use of extruded linseed or linseed oil only decreased the carcass fatness of the standard chickens but had no effect on the carcass fatness of Label Rouge chickens. The nutritional quality of raw and cured-cooked meat was improved (increased concentration of n-3 FA), whereas the technological quality of the meat (pH, juice loss after cold storage, susceptibility to oxidation, colour, processing yield and shear force value) and sensory quality of the processed products were not or slightly affected. 4. Linked to lower breast yield, to lower lipid content in breast meat and to higher slaughter age, Label Rouge chickens seemed to be less efficient for n-3 FA deposition in breast muscles than standard chickens. PMID:23647182

Baeza, E; Chartrin, P; Gigaud, V; Tauty, S; Meteau, K; Lessire, M; Berri, C

2013-01-01

89

Low-mass supernovae in the early Galactic halo: source of the double r/s-process enriched halo stars?  

E-print Network

Several stars at the low-metallicity extreme of the Galactic halo ([Fe/H]=-2.5) show strong enhancements of both s-process and r-process elements. The presence of s-process elements in main-sequence stars is explained via mass transfer from an AGB companion star in a binary system. r-Process elements originate in type-II supernovae and also require mass transfer. It is however unclear how pollution by both an AGB star and a supernova could have occured. Here I show that the initial--final-mass relation steepens at low metallicity, due to low mass-loss efficiency. This may cause the degenerate cores of low-Z, high-mass AGB stars to reach the Chandresekhar mass, leading to an Iben & Renzini-type-1.5 supernova. Such supernovae can explain both the enhancement patterns and the metallicity dependence of the double-enhanced halo stars. Reduced mass loss efficiency predicts more massive remnants in metal-poor globular clusters. The evidence for a high M/L population in the cores of globular clusters is briefly discussed.

Albert A. Zijlstra

2003-12-18

90

Nutrient enrichment, phytoplankton algal growth, and estimated rates of instream metabolic processes in the Quinebaug River Basin, Connecticut, 2000-2001  

USGS Publications Warehouse

A consistent and pervasive pattern of nutrient enrichment was substantiated by water-quality sampling in the Quinebaug River and its tributaries in eastern Connecticut during water years 2000 and 2001. Median total nitrogen and total phosphorus concentrations exceeded the U.S. Environmental Protection Agency?s recently recommended regional ambient water-qual-ity criteria for streams (0.71 and 0.031 milligrams per liter, respectively). Maximum total phosphorus concentrations exceeded 0.1 milligrams per liter at nearly half the sampled locations in the Quinebaug River Basin. Elevated total nitrogen and total phosphorus concentrations were measured at all stations on the mainstem of the Quinebaug River, the French River, and the Little River. Nutrient enrichment was related to municipal wastewater point sources at the sites on the mainstem of the Quinebaug River and French River, and to agricultural nonpoint nutrient sources in the Little River Basin. Nutrient enrichment and favorable physical factors have resulted in excessive, nuisance algal blooms during summer months, particularly in the numerous impoundments in the Quinebaug River system. Phytoplankton algal density as high as 85,000 cells per milliliter was measured during such nuisance blooms in water years 2000 and 2001. Different hydrologic conditions during the summers of 2000 and 2001 produced very different seston algal populations. Larger amounts of precipitation sustained higher streamflows in the summer of 2000 (than in 2001), which resulted in lower total algal abundance and inhibited the typical algal succession from diatoms to cyanobacteria. Despite this, nearly half of all seston chlorophyll-a concentrations measured during this study exceeded the recommended regional ambient stream-water-quality criterion (3.75 micrograms per liter), and seston chlorophyll-a concentrations as large as 42 micrograms per liter were observed in wastewa-ter-receiving reaches of the Quinebaug River. Estimates of primary productivity and respiration obtained from diel dissolved oxygen monitoring and from light- and dark-bottle dissolved oxygen measurements demonstrated that instream metabolic processes are consistent with a seston-algae dominant system. The highest estimated maximum primary productivity rate was 1.72 grams of oxygen per cubic meter per hour at the Quinebaug River at Jewett City during September 2001. The observed extremes in diel dissolved oxygen concentrations (less than 5 milligrams per liter) and pH (greater than 9) may periodically stress aquatic organisms in the Quinebaug River Basin.

Colombo, Michael J.; Grady, Stephen J.; Todd Trench, Elaine C.

2004-01-01

91

Puzzling Origin of CEMP-r/s Stars: An Interpretation of Abundance and Enrichment of s- and r-Process Elements from Asymptotic Giant Branch Supernovae  

NASA Astrophysics Data System (ADS)

CEMP-r/s stars at low metallicity are known as double-enhanced stars that show enhancements of both r-process and s-process elements. The chemical abundances of these very metal-poor stars provide us a lot of information for putting new restraints on models of neutron-capture processes. In this article, we put forward an accreted scenario in which the double enrichment of r-process and s-process elements is caused by a former intermediate-mass Asymptotic Giant Branch (AGB) companion in a detached binary system. As the AGB superwind is only present at the ultimate phase of AGB stars, there is thus a lot of potential that the degenerate-core mass of an intermediate-mass AGB star reaches the Chandrasekhar limit before the AGB superwind. In these circumstances, both s-process elements produced in the AGB shell and r-process elements synthesized in the subsequent explosion would be sprayed contemporaneously and accreted by its companion. Despite similarity to physical conditions of a core-collapse supernova, a major focus in this scenario is the degenerate C-O core surrounded by an envelope of a former intermediate-mass AGB donor that may collapse and explode. Due to the existence of an outer envelope, r-process nucleosynthesis is expected to occur. Hypothesizing the material-rich europium (Eu) accreted by the secondary via the wind from the supernova to be in proportion to the geometric fraction of the companion with respect to the exploding donor star, we find that the estimated yield of Eu (as representative of r-process elements) per AGB supernova event is about 1 × 10-9 M ? ˜ 5 × 10-9 M ?. Using the yields of Eu, the overabundance of r-process elements in CEMP-r/s stars can be accounted for. The calculated results show that the value of parameter f , standing for efficiency of wind pollution from the AGB supernova, will reach about 104, which means that the enhanced factor is much larger than unity due to the impact of gravity of the donor and the result of the gravitational focusing effect of the companion.

Zhang, Jiang; Zhao, Fang; Chen, Yanping; Cui, Wenyuan; Zhang, Bo

2013-12-01

92

Progress in developing processes for converting {sup 99}Mo production from high- to low-enriched uranium--1998.  

SciTech Connect

During 1998, the emphasis of our activities was focused mainly on target fabrication. Successful conversion requires a reliable irradiation target; the target being developed uses thin foils of uranium metal, which can be removed from the target hardware for dissolution and processing. This paper describes successes in (1) improving our method for heat-treating the uranium foil to produce a random-small grain structure, (2) improving electrodeposition of zinc and nickel fission-fragment barriers onto the foil, and (3) showing that these fission fragment barriers should be stable during transport of the targets following irradiation. A method was also developed for quantitatively electrodepositing uranium and plutonium contaminants in the {sup 99}Mo. Progress was also made in broadening international cooperation in our development activities.

Conner, C.

1998-10-28

93

Where does the carbon go? A model–data intercomparison of vegetation carbon allocation and turnover processes at two temperate forest free-air CO2 enrichment sites  

PubMed Central

Elevated atmospheric CO2 concentration (eCO2) has the potential to increase vegetation carbon storage if increased net primary production causes increased long-lived biomass. Model predictions of eCO2 effects on vegetation carbon storage depend on how allocation and turnover processes are represented. We used data from two temperate forest free-air CO2 enrichment (FACE) experiments to evaluate representations of allocation and turnover in 11 ecosystem models. Observed eCO2 effects on allocation were dynamic. Allocation schemes based on functional relationships among biomass fractions that vary with resource availability were best able to capture the general features of the observations. Allocation schemes based on constant fractions or resource limitations performed less well, with some models having unintended outcomes. Few models represent turnover processes mechanistically and there was wide variation in predictions of tissue lifespan. Consequently, models did not perform well at predicting eCO2 effects on vegetation carbon storage. Our recommendations to reduce uncertainty include: use of allocation schemes constrained by biomass fractions; careful testing of allocation schemes; and synthesis of allocation and turnover data in terms of model parameters. Data from intensively studied ecosystem manipulation experiments are invaluable for constraining models and we recommend that such experiments should attempt to fully quantify carbon, water and nutrient budgets. PMID:24844873

De Kauwe, Martin G; Medlyn, Belinda E; Zaehle, Sönke; Walker, Anthony P; Dietze, Michael C; Wang, Ying-Ping; Luo, Yiqi; Jain, Atul K; El-Masri, Bassil; Hickler, Thomas; Wårlind, David; Weng, Ensheng; Parton, William J; Thornton, Peter E; Wang, Shusen; Prentice, I Colin; Asao, Shinichi; Smith, Benjamin; McCarthy, Heather R; Iversen, Colleen M; Hanson, Paul J; Warren, Jeffrey M; Oren, Ram; Norby, Richard J

2014-01-01

94

Enrichment of Very Metal-Poor Stars with Both r-Process and s-Process Elements from 8-10 M_\\odot Stars  

E-print Network

Recent spectroscopic studies have revealed the presence of numerous carbon-enhanced, metal-poor stars with [Fe/H] < -2.0 that exhibit strong enhancements of s-process elements. These stars are believed to be the result of a binary mass-transfer episode from a former asymptotic giant-branch (AGB) companion that underwent s-process nucleosynthesis. However, several such stars exhibit significantly lower Ba/Eu ratios than solar s-process abundances. This might be explained if there were an additional contribution from the r-process, thereby diluting the Ba/Eu ratio by extra production of Eu. We propose a model in which the double enhancements of r-process and s-process elements originate from a former 8-10 M_\\odot companion in a wide binary system, which may undergo s-processing during an AGB phase, followed by r-processing during its subsequent supernova explosion. The mass of Eu (as representative of r-process elements) captured by the secondary through the wind from the supernova is estimated, which is assumed to be proportional to the geometric fraction of the secondary (low-mass, main-sequence) star with respect to the primary (exploding) star. We find that the estimated mass is in good agreement with a constraint on the Eu yield per supernova event obtained from a Galactic chemical evolution study, when the initial orbital separation is taken to be \\sim 1 year. If one assumes an orbital period on the order of five years, the efficiency of wind pollution from the supernova must be enhanced by a factor of \\sim 10. This may, in fact, be realized if the expansion velocity of the supernova's innermost ejecta, in which the r-process has taken place, is significantly slow, resulting in an enhancement of accretion efficiency by gravitational focusing.

S. Wanajo; K. Nomoto; N. Iwamoto; Y. Ishimaru; T. C. Beers

2005-09-27

95

Fluorine in the rocks and sediments of volcanic areas in central Italy: total content, enrichment and leaching processes and a hypothesis on the vulnerability of the related aquifers.  

PubMed

Rock, sediment and water samples from areas characterised by hydrothermal alterations in the Sabatini and Vico Volcanic Districts, near Rome and the large city of Viterbo, respectively, were collected and analysed to determine the total fluorine (F) content and to understand the F geochemical background level in the volcanic districts of central Italy. Leaching and alteration processes controlling the high concentration of F in water were also investigated. Fluorine concentrations were directly determined (potentiometrically) by an F selective electrode in water samples, while the procedure for rock samples included preliminary F dissolution through alkaline fusion. F concentrations higher than 800 mg kg(-1) were commonly found in the analysed rocks and sediments; the concentration depended on the lithology and on the distance from the alteration areas. A specific successive sampling campaign was conducted in three areas where the F content in sediments was particularly high; in the same areas, measurements of CO(2) flux were also performed to investigate the possible deep origin of F. To verify the relationships among the high F contents in rocks and sediments, the leaching processes involved and the presence of F in the aquifer, we also collected water samples in the western sector of the Sabatini Volcanic District, where hydrothermal manifestations and mineral springs are common. The data were processed using a GIS system in which the F distribution was combined with morphological and geological observations. The main results of our study are that (1) F concentrations are higher in volcanic and recently formed travertine (especially in hydrothermally altered sediments) than in sedimentary rocks and decrease with distance from hydrothermal alteration areas, (2) F is more easily leached from hydrothermally altered rocks and from travertine and (3) sediments enriched with F may indicate the presence of deep regional fractures that represent direct pathways of hydrothermal fluids from the crust to the surface. PMID:21968879

De Rita, Donatella; Cremisini, Carlo; Cinnirella, Alessandro; Spaziani, Fabio

2012-09-01

96

Biomass gasification and in-bed contaminants removal: performance of iron enriched olivine and bauxite in a process of steam/O2 gasification.  

PubMed

A modified Olivine, enriched in iron content (10% Fe/Olivine), and a natural bauxite, were tested in the in-bed reduction of tar and alkali halides (NaCl and KCl) released in a process of biomass steam/O(2) gasification. The tests were carried out at an ICBFB bench scale reactor under the operating conditions of: 855-890 °C, atmospheric pressure, 0.5 steam/biomass and 0.33 ER ratios. From the use of the two materials, a reduction in the contaminant contents of the fuel gas produced was found. For the alkali halides, a decrease up to 70%(wt) was observed for the potassium concentration, while for sodium, the reduction was found to be quite poor. For the organic content, compared to unmodified Olivine, the chromatographically determined total tar quantity showed a removal efficiency of 38%(wt). Moreover, regarding the particulate content a rough doubling in the fuel gas revealed a certain brittleness of the new bed material. PMID:22705523

Barisano, D; Freda, C; Nanna, F; Fanelli, E; Villone, A

2012-08-01

97

A Mock UF6 Feed and Withdrawal System for Testing Safeguards Monitoring Systems and Strategies Intended for Nuclear Fuel Enrichment and Processing Plants  

SciTech Connect

This report describes an engineering-scale, mock UF6 feed and withdrawal (F&W) system, its operation, and its intended uses. This system has been assembled to provide a test bed for evaluating and demonstrating new methodologies that can be used in remote, unattended, continuous monitoring of nuclear material process operations. These measures are being investigated to provide independent inspectors improved assurance that operations are being conducted within declared parameters, and to increase the overall effectiveness of safeguarding nuclear material. Testing applicable technologies on a mock F&W system, which uses water as a surrogate for UF6, enables thorough and cost-effective investigation of hardware, software, and operational strategies before their direct installation in an industrial nuclear material processing environment. Electronic scales used for continuous load-cell monitoring also are described as part of the basic mock F&W system description. Continuous monitoring components on the mock F&W system are linked to a data aggregation computer by a local network, which also is depicted. Data collection and storage systems are described only briefly in this report. The mock UF{sub 6} F&W system is economical to operate. It uses a simple process involving only a surge tank between feed tanks and product and withdrawal (or waste) tanks. The system uses water as the transfer fluid, thereby avoiding the use of hazardous UF{sub 6}. The system is not tethered to an operating industrial process involving nuclear materials, thereby allowing scenarios (e.g., material diversion) that cannot be conducted otherwise. These features facilitate conducting experiments that yield meaningful results with a minimum of expenditure and quick turnaround time. Technologies demonstrated on the engineering-scale system lead to field trials (described briefly in this report) for determining implementation issues and performance of the monitoring technologies under plant operating conditions. The ultimate use of technologies tested on the engineering-scale test bed is to work with safeguards agencies to install them in operating plants (e.g., enrichment and fuel processing plants), thereby promoting new safeguards measures with minimal impact to operating plants. In addition, this system is useful in identifying features for new plants that can be incorporated as part of 'safeguards by design,' in which load cells and other monitoring technologies are specified to provide outputs for automated monitoring and inspector evaluation.

Krichinsky, Alan M [ORNL; Bates, Bruce E [ORNL; Chesser, Joel B [ORNL; Koo, Sinsze [ORNL; Whitaker, J Michael [ORNL

2009-12-01

98

Effect of prior growth temperature, type of enrichment medium, and temperature and time of storage on recovery of Listeria monocytogenes following high pressure processing of milk  

Microsoft Academic Search

A five-isolate cocktail of Listeria monocytogenes (103 cfu\\/ml in skim or whole raw milk) was subjected to 450 MPa for 900 s or 600 MPa for 90 s. The effects of prior growth temperature, type of milk (skim vs. whole), type of recovery-enrichment media (optimized Penn State University [oPSU] broth, Listeria Enrichment Broth [LEB], Buffered LEB [BLEB], Modified BLEB [MBLEB],

Michelle K. Bull; Melinda M. Hayman; Cynthia M. Stewart; Elizabeth A. Szabo; Stephen J. Knabel

2005-01-01

99

Derived enriched uranium market  

Microsoft Academic Search

The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived

Rutkowski

1996-01-01

100

Air separation with medium pressure enrichment  

Microsoft Academic Search

A cryogenic air separation process is disclosed wherein the low pressure column section of a doubler is caused to operate closer to equilibrium and, hence, more efficiently by incorporating a medium pressure column which further enriches HP column enriched oxygen liquid before introduction into the LP column. The MP column is reboiled by indirect heat exchange with condensing HP column

1984-01-01

101

Laser enrichment of uranium: the proliferation connection  

Microsoft Academic Search

The implications of laser enrichment of U for nuclear weapons proliferation are examined in this article. The economic aspects of laser enrichment of U are not considered except as they affect the proliferation issues. The basic physical processes involved in laser isotope separation in atomic and molecular U are discussed in some detail. Technical difficulties that must be overcome before

A. S. Krass

1977-01-01

102

Enrichment of light hydrocarbon mixture  

SciTech Connect

Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

Yang; Dali (Los Alamos, NM); Devlin, David (Santa Fe, NM); Barbero, Robert S. (Santa Cruz, NM); Carrera, Martin E. (Naperville, IL); Colling, Craig W. (Warrenville, IL)

2010-08-10

103

Enrichment of light hydrocarbon mixture  

DOEpatents

Light hydrocarbon enrichment is accomplished using a vertically oriented distillation column having a plurality of vertically oriented, nonselective micro/mesoporous hollow fibers. Vapor having, for example, both propylene and propane is sent upward through the distillation column in between the hollow fibers. Vapor exits neat the top of the column and is condensed to form a liquid phase that is directed back downward through the lumen of the hollow fibers. As vapor continues to ascend and liquid continues to countercurrently descend, the liquid at the bottom of the column becomes enriched in a higher boiling point, light hydrocarbon (propane, for example) and the vapor at the top becomes enriched in a lower boiling point light hydrocarbon (propylene, for example). The hollow fiber becomes wetted with liquid during the process.

Yang, Dali (Los Alamos, NM); Devlin, David (Santa Fe, NM); Barbero, Robert S. (Santa Cruz, NM); Carrera, Martin E. (Naperville, IL); Colling, Craig W. (Warrenville, IL)

2011-11-29

104

Evolution of the South African mantle—a case study of garnet peridotites from the Finsch diamond mine (Kaapvaal craton); Part 2: Multiple depletion and re-enrichment processes  

NASA Astrophysics Data System (ADS)

Recalculated whole rock major-, trace-element and isotope compositions from mineral analyses of Finsch mantle peridotites indicate a complex history of the South African sub-continental lithospheric mantle (SA-SCLM). According to the Lu-Hf whole rock isotopic data last depletion coupled with the final cratonization of the Kaapvaal craton underneath Finsch occurred at ~ 2.6 Ga. The data of this study indicate several depletion and enrichment processes during that early history of Finsch SCLM. Calculated degrees of partial melting using major and rare earth element (REE) compositions show that all depletion episodes together have removed more than 40% of melt from the SA-SCLM. As indicated by elevated Hf concentrations and subchondritic Lu/Hf, many Finsch peridotites were metasomatically overprinted between the last and earlier depletion stages. Silica enrichment, expressed in high modal abundance of orthopyroxene in the majority of the samples likely took place at that early stage. The last coupled melting and re-enrichment event (at ~ 2.6 Ga) resulted in complete re-equilibration of trace element and Hf isotope signatures at the whole rock scale and thus, erased most signs of previous events. After the final depletion and before the final kimberlite eruption, the Finsch mantle suffered from further metasomatic overprints. Metasomatism is expressed in the enrichment of light REE (LREE) and some large ion lithophile elements (e.g. Sr, Rb, Th). Additionally, the Nd isotope signatures of all samples as well as the Hf isotope compositions of some samples were modified. Late enrichment is documented by a modally metasomatized sample that contains rutile and sulfide. This sample is characterized by strong enrichment of high-field-strength elements and LREE and was probably overprinted with a sulfide bearing silico-carbonatitic melt with high contents of Ti, Fe and Ni. This melt likely originated from an enriched mantle that was isolated for a long time during which it developed a very unradiogenic Hf isotope signature, characteristic for this type of metasomatism.

Lazarov, Marina; Brey, Gerhard P.; Weyer, Stefan

2012-12-01

105

Oxygen-enriched air for MHD power plants  

Microsoft Academic Search

Cryogenic air-separation process cycle variations and compression schemes are examined. They are designed to minimize net system power required to supply pressurized, oxygen-enriched air to the combustor of an MHD power plant with a coal input of 2000 MWt. Power requirements and capital costs for oxygen production and enriched air compression for enrichment levels from 13 to 50% are determined.

R. W. Ebeling Jr.; J. A. Burkhart

1979-01-01

106

Strong arsenic enrichment in sediments from the Elqui watershed, Northern Chile: industrial (gold mining at El Indio–Tambo district) vs. geologic processes  

Microsoft Academic Search

Sediments from the Elqui watershed river system (9800 km2; northern Chile) are highly enriched in arsenic. The river system initiates in the high altitude domain of the Andes (3500–4000 m) and drains important hydrothermal alteration zones and epithermal deposits, including the copper-, and arsenic-rich gold veins of the well-known El Indio–Tambo district. In order to study the extent, source, and

R. Oyarzun; J. Lillo; P. Higueras; J. Oyarzún; H. Maturana

2004-01-01

107

Glycoprotein Enrichment Resin User Manual  

E-print Network

Glycoprotein Enrichment Resin User Manual Cat. No. 635647 PT4050-1 (PR912675) Published 14 January Laboratories, Inc. Version No. PR912675 ATakara Bio Company 2 Glycoprotein Enrichment Resin User Manual I.................................................................................................4 IV. Glycoprotein Enrichment

Lebendiker, Mario

108

Laser and gas centrifuge enrichment  

SciTech Connect

Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

Heinonen, Olli [Senior Fellow, Belfer Center for Science and International Affairs, Harvard Kennedy School, Cambridge, Massachusetts (United States)

2014-05-09

109

Laser and gas centrifuge enrichment  

NASA Astrophysics Data System (ADS)

Principles of uranium isotope enrichment using various laser and gas centrifuge techniques are briefly discussed. Examples on production of high enriched uranium are given. Concerns regarding the possibility of using low end technologies to produce weapons grade uranium are explained. Based on current assessments commercial enrichment services are able to cover the global needs of enriched uranium in the foreseeable future.

Heinonen, Olli

2014-05-01

110

Teaching Mathematical Modelling: Demonstrating Enrichment and Elaboration  

ERIC Educational Resources Information Center

This paper uses a series of models to illustrate one of the fundamental processes of model building--that of enrichment and elaboration. The paper describes how a problem context is given which allows a series of models to be developed from a simple initial model using a queuing theory framework. The process encourages students to think about the…

Warwick, Jon

2015-01-01

111

Centrifuge enrichment plants. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the design, control, monitoring, and safety of centrifuge enrichment plants. Power supplies, enrichment plant safeguards, facility design, cascade heater test loops to monitor the enrichment process, inspection strategies, and the socioeconomic effects of centrifuge enrichment plants are examined. Radioactive waste disposal problems are considered. (Contains a minimum of 172 citations and includes a subject term index and title list.)

Not Available

1994-03-01

112

Centrifuge enrichment plants. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the design, control, monitoring, and safety of centrifuge enrichment plants. Power supplies, enrichment plant safeguards, facility design, cascade heater test loops to monitor the enrichment process, inspection strategies, and the socioeconomic effects of centrifuge enrichment plants are examined. Radioactive waste disposal problems are considered. (Contains a minimum of 171 citations and includes a subject term index and title list.)

NONE

1993-09-01

113

Enrichments in Biology  

ERIC Educational Resources Information Center

Emphasizes the need for enrichment materials in addition to laboratory and textbook work, particularly for interested and able students. Discusses the use of filmstrips, loop films, Innovations to Inquiry, BSCS pamphlets, newspapers, magazines and scientific periodicals, television, field trips, library resources, and programed units. (EB)

Richard, Paul W.

1969-01-01

114

Toxicology Enrichment Materials  

NSDL National Science Digital Library

The series contains fact sheets on toxicology, introductory exercises to familiarize students with the study of toxicology and student assignments addressing specific issues in toxicology. The assignments are designed to enrich typical course curricula and give students practice using information from both library and internet sources.

Suzanne Conklin (Rhode Island College; )

2000-01-01

115

Weakly enriched higher categories  

E-print Network

The goal of this thesis is to begin to lay the foundations for a theory of enriched [infinity]categories. We introduce a definition of such objects, based on a non-symmetric version of Lurie's theory of [infinity]-operads. ...

Haugseng, Rune

2013-01-01

116

Enriching the Catalog  

ERIC Educational Resources Information Center

After decades of costly and time-consuming effort, nearly all libraries have completed the retrospective conversion of their card catalogs to electronic form. However, bibliographic systems still are really not much more than card catalogs on wheels. Enriched content that Amazon.com takes for granted--such as digitized tables of contents, cover…

Tennant, Roy

2004-01-01

117

The Enriched Xenon Observatory  

SciTech Connect

The Enriched Xenon Observatory (EXO) experiment will search for neutrinoless double beta decay of {sup 136}Xe. The EXO Collaboration is actively pursuing both liquid-phase and gas-phase Xe detector technologies with scalability to the ton-scale. The search for neutrinoless double beta decay of {sup 136}Xe is especially attractive because of the possibility of tagging the resulting Ba daughter ion, eliminating all sources of background other than the two neutrino decay mode. EXO-200, the first phase of the project, is a liquid Xe time projection chamber with 200 kg of Xe enriched to 80% in {sup 136}Xe. EXO-200, which does not include Ba-tagging, will begin taking data in 2009, with two-year sensitivity to the half-life for neutrinoless double beta decay of 6.4x10{sup 25} years. This corresponds to an effective Majorana neutrino mass of 0.13 to 0.19 eV.

Dolinski, M. J. [Stanford University Physics Department, 382 Via Pueblo Mall, Stanford, CA 94305-4060 (United States)

2009-12-17

118

US developments in technology for uranium enrichment  

SciTech Connect

The purpose of this paper is to review recent progress and the status of the work in the United States on that part of the fuel cycle concerned with uranium enrichment. The United States has one enrichment process, gaseous diffusion, which has been continuously operated in large-scale production for the past 37 years; another process, gas centrifugation, which is now in the construction phase; and three new processes, molecular laser isotope separation, atomic vapor laser isotope separation, plasma separation process, in which the US has also invested sizable research and development efforts over the last few years. The emphasis in this paper is on the technical aspects of the various processes, but the important economic factors which will define the technological mix which may be applied in the next two decades are also discussed.

Wilcox, W.J. Jr.; McGill, R.M.

1982-01-01

119

Parents as Partners in Art Education Enrichment  

ERIC Educational Resources Information Center

The author describes a parent art program, how it works, and ways to implement it. She emphasizes the strengths of parent programs as a way to support and enrich existing arts education, not as a replacement. Hansen describes the art kit--the adult's teaching resource--and the basic four-part process: presentation, demonstration, an art activity,…

Hansen, Laurie

2008-01-01

120

Text-based Legal Ontology Enrichment  

Microsoft Academic Search

The acquisition of knowledge from text is an incomplete and incre- mental process. When anchored to a particular knowledge model it provides po- tentially useful information to the legal expert in the form of new concepts and relations, in order to improve the domain coverage. This paper explores the fea- sibility of various legal text-based ontology enrichment techniques, and dis-

Wim Peters

121

COMPARISON OF EFFECTS OF HIGH PRESSURE PROCESSING AND HEAT TREATMENT ON IMMUNOACTIVITY OF BOVINE MILK IMMUNOGLOBULIN G IN ENRICHED SOYMILK UNDER EQUIVALENT MICROBIAL INACTIVATION LEVELS  

Technology Transfer Automated Retrieval System (TEKTRAN)

Immunoglobulin G (IgG) is a protein that benefits consumers by providing stronger tolerance to microbial infections. IgG usually is added to foods such as cow’s milk or soymilk to serve as functional foods. IgG is sensitive to heat. Traditional canning will destroy IgG. New process needs to be devel...

122

Status of gadolinium enrichment technology at LLNL  

SciTech Connect

A method based on,polarization selectivity and three step laser photoionization is presented for separation of the odd isotopes of gadolinium. Measurements of the spectroscopic parameters needed to quantify the excitation pathway are discussed. Model results are presented for the efficiency of photoionization. The vapor properties of electron beam vaporized gadolinium are presented which show dramatic cooling during the expansion of the hot dense vapor into a vacuum. This results in a significant increase in the efficiency of conversion of natural feed into enriched product in the AVLIS process. Production of enriched gadolinium for use in commercial power reactors appears to be economically viable using technology in use at LLNL.

Haynam, C.; Comaskey, B.; Conway, J.; Eggert, J.; Glaser, J.; Ng, E.; Paisner, J.; Solarz, R.; Worden, E.

1993-01-01

123

Clogging the enrichment bypass  

SciTech Connect

The issue that has come to be known as the bypass is the latest dispute in the continuing saga of uranium trade between the United States and the Commonwealth of Indepenent States. Bypass deals now being conducted by US utilities have drawn heavy criticism from the US Department of Commerce but are perfectly legal under the terms of the Suspension Agreements. Urged on by the United States Enrichment Corporation, the US DOC intends to stop, or at least severely restrict, bypass deals. Using a recent agreement with Kazakhstan as a case study, this article reviews the implications of such bypass deals.

NONE

1995-05-01

124

76 FR 11523 - Atomic Safety and Licensing Board; AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility...  

Federal Register 2010, 2011, 2012, 2013, 2014

...AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility); Notice of Opportunity...construct and operate its proposed Eagle Rock Enrichment Facility (EREF) in Bonneville...AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility), 74 FR...

2011-03-02

125

Withdrawal assay monitoring at US Enrichment Facilities  

SciTech Connect

The United States Enrichment Corporation (USEC) controls two uranium enrichment facilities that produce enriched uranium for both military and commercial use. The process requires both feed and withdrawal operations. The withdrawal process requires both product (enriched uranium) withdrawal stations and tails (depleted uranium) withdrawal stations. A previous prototype system, ``X-330 Tails Cylinder Assay Monitor,`` was developed as a demonstration for the tails withdrawal station at the Portsmouth Gaseous Diffusion Plant (PORTS). The prototype system was done in response to potential problems with the original method for determining the hourly weighted assay averages that are used to calculate the final weighted assay of the cylinder. In the original method the {sup 235}U assay of uranium hexaflouride withdrawn from PORTS cascade into tails cylinders is determined every 5 min by measurements from an in-line assay mass spectrometer. An average value for a 1-h period is then calculated by area control room personnel and assigned to the accumulated weight in the cylinder for the period. A potential problem with this method is that cylinder weight is not automatically recorded as often as the assay. The assay and withdrawal rate can both vary during the given period. This variation results in inaccuracies in the hourly weighted assays that are used to calculate the final weighted assay of the cylinder. Laboratory analysis is considered to be the most accurate method for determining the final cylinder assay; however, the cost and safety considerations of redundant cylinder handling limit the number of cylinders sampled to less than 10%.

Smith, D.E.

1996-01-01

126

Centrifuge enrichment plants. January 1970-October 1988 (Citations from the NTIS data base). Report for January 1970-October 1988  

SciTech Connect

This bibliography contains citations concerning the design, control, monitoring, and safety of centrifuge enrichment plants. Power supplies, enrichment plant safeguards, facility design, cascade heater test loops to monitor the enrichment process, inspection strategies, and the socio-economic effects of centrifuge enrichment plants are examined. Radioactive waste disposal problems are briefly considered. (Contains 151 citations fully indexed and including a title list.)

Not Available

1988-11-01

127

Stress-induced selection of a single species from an entire meiobenthic nematode assemblage: is this possible using iron enrichment and does pre-exposure affect the ease of the process?  

PubMed

The present work proposes a new experimental design using iron enrichment to select a single species from an entire meiobenthic nematode community. The high diversity of nematodes makes it impossible to study their responses to stressors in terms of chemical biomarkers, as this kind of research demands a single species as a form of biological material. Two assemblages, one from a control site (Canal) and one from an iron-contaminated site (Fouledh) in Bizerte Lagoon (Tunisia), were used to validate the protocol and to study whether pre-exposure to iron could affect the ease of the selection process. Analyses of variance suggested that the abundance and species number of nematodes from the Canal and Fouledh sites decreased discernibly with exposure to iron. Multivariate analyses performed on nematode abundances revealed that Oncholaimus campylocercoides, Sabatieria granifer, Sabatieria punctata and Theristus flevensis were the most tolerant species, probably due to their deposit-feeding behaviour. Species with a restricted feeding spectrum showed a low tolerance potential. At the end of the experiment, O. campylocercoides became the unique component of the nematode community from both sites. The complete alteration of the community was achieved with more difficulty for nematodes from Fouledh than for those from Canal. The identity of the selected species was confirmed at both the morphological levels and by sequencing the nuclear small subunit ribosomal DNA (18S rDNA). PMID:25167819

Boufahja, F; Semprucci, F

2015-02-01

128

High-purity enrichment of 84Sr  

NASA Astrophysics Data System (ADS)

High-purity 84Sr (i.e., >99 at%) is an important tool in many areas of basic and applied research, in particular for spikes used in isotopic dilution/mass spectrometer investigations in geochemistry, cosmochemistry, and paleoclimate-age studies. In nature, the 84Sr abundance is only 0.56%; however, it can be enriched to the specified requirements by using a high-resolution separator, such as the 180°-sector separator, or by completing two passes through a high-production, lower-resolution machine, such as the calutron. The latter option was used for this enrichment to produce ˜1 g of strontium with a final 84Sr concentration of 99.64%. Three innage runs were made, vaporizing a total of ˜17 g of metal feed that had been pre-enriched in the calutron to ˜70% 84Sr. A partial recovery, followed by recycle of the unresolved feed, was made after the second innage run. A process efficiency of 8.44% was achieved, and 4.33 g of the unresolved feed material was recovered. A modified ion-source unit using materials compatible with strontium and the use of krypton as mass markers to aid in operations are described. Standard contamination analyses were performed to evaluate the enrichment and to compare measured results with predicted product purity.

Tracy, J. G.

1999-12-01

129

Oxygen-enriched air for MHD power plants  

NASA Technical Reports Server (NTRS)

Cryogenic air-separation process cycle variations and compression schemes are examined. They are designed to minimize net system power required to supply pressurized, oxygen-enriched air to the combustor of an MHD power plant with a coal input of 2000 MWt. Power requirements and capital costs for oxygen production and enriched air compression for enrichment levels from 13 to 50% are determined. The results are presented as curves from which total compression power requirements can be estimated for any desired enrichment level at any delivery pressure. It is found that oxygen enrichment and recuperative heating of MHD combustor air to 1400 F yields near-term power plant efficiencies in excess of 45%. A minimum power compression system requires 167 MW to supply 330 lb of oxygen per second and costs roughly 100 million dollars. Preliminary studies show MHD/steam power plants to be competitive with plants using high-temperature air preheaters burning gas.

Ebeling, R. W., Jr.; Cutting, J. C.; Burkhart, J. A.

1979-01-01

130

Enriching Ontology for Deep Web Search  

Microsoft Academic Search

This paper addresses the problems of extracting instances from the Deep Web, enriching a domain specific ontology with those\\u000a instances, and using this ontology to improve Web search. Extending an existing ontology with a large number of instances\\u000a extracted from the Deep Web is an important process for making the ontology more usable for indexing of Deep Web sites. We

Yoo Jung An; Soon Ae Chun; Kuo-chuan Huang; James Geller

2008-01-01

131

Uranium enrichment export control guide: Gaseous diffusion  

SciTech Connect

This document was prepared to serve as a guide for export control officials in their interpretation, understanding, and implementation of export laws that relate to the Zangger International Trigger List for gaseous diffusion uranium enrichment process components, equipment, and materials. Particular emphasis is focused on items that are especially designed or prepared since export controls are required for these by States that are party to the International Nuclear Nonproliferation Treaty.

Not Available

1989-09-01

132

High Accuracy U-235 Enrichment Verification Station for Low Enriched Uranium Alloys  

SciTech Connect

The Y-12 National Security Complex is playing a role in the U.S. High Performance Research Reactor (USHPRR) Conversion program sponsored by the U.S. National Nuclear Security Administration's Office of Global Threat Reduction. The USHPRR program has a goal of converting remaining U.S. reactors that continue to use highly enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. The USHPRR program is currently developing a LEU Uranium-Molybdenum (U-Mo) monolithic fuel for use in the U.S. high performance research reactors.Y-12 is supporting both the fuel development and fuel fabrication efforts by fabricating low enriched U-Mo foils from its own source material for irradiation experiments and for optimizing the fabrication process in support of scaling up the process to a commercial production scale. Once the new fuel is qualified, Y-12 will produce and ship U-Mo coupons with verified 19.75% +0.2% - 0.3% U-235 enrichment to be fabricated into fuel elements for the USHPRRs. Considering this small enrichment tolerance and the transition into HEU being set strictly at 20% U-235, a characterization system with a measurement uncertainty of less than or equal to 0.1% in enrichment is desired to support customer requirements and minimize production costs. Typical uncertainty for most available characterization systems today is approximately 1-5%; therefore, a specialized system must be developed which results in a reduced measurement uncertainty. A potential system using a High-Purity Germanium (HPGe) detector has been procured, and tests have been conducted to verify its capabilities with regards to the requirements. Using four U-Mo enrichment standards fabricated with complete isotopic and chemical characterization, infinite thickness and peak-ratio enrichment measurement methods have been considered for use. As a result of inhomogeneity within the U-Mo samples, FRAM, an isotopic analysis software, has been selected for initial testing. A systematic approach towards observing effects on FRAM's enrichment analysis has been conducted with regards to count and dead time.

Lillard, C. R.; Hayward, J. P.; Williamson, M. R.

2012-06-07

133

Centrifuge enrichment plants. (Latest citations from the NTIS data base). Published Search  

SciTech Connect

The bibliography contains citations concerning the design, control, monitoring, and safety of centrifuge enrichment plants. Power supplies, enrichment plant safeguards, facility design, cascade heater test loops to monitor the enrichment process, inspection strategies, and the socioeconomic effects of centrifuge enrichment plants are examined. Radioactive waste disposal problems are briefly considered. (Contains a minimum of 169 citations and includes a subject term index and title list.)

Not Available

1992-09-01

134

City model enrichment  

NASA Astrophysics Data System (ADS)

The combination of mobile communication technology with location and orientation aware digital cameras has introduced increasing interest in the exploitation of 3D city models for applications such as augmented reality and automated image captioning. The effectiveness of such applications is, at present, severely limited by the often poor quality of semantic annotation of the 3D models. In this paper, we show how freely available sources of georeferenced Web 2.0 information can be used for automated enrichment of 3D city models. Point referenced names of prominent buildings and landmarks mined from Wikipedia articles and from the OpenStreetMaps digital map and Geonames gazetteer have been matched to the 2D ground plan geometry of a 3D city model. In order to address the ambiguities that arise in the associations between these sources and the city model, we present procedures to merge potentially related buildings and implement fuzzy matching between reference points and building polygons. An experimental evaluation demonstrates the effectiveness of the presented methods.

Smart, Philip D.; Quinn, Jonathan A.; Jones, Christopher B.

135

PROPULSE 980: A Hydrogen Peroxide Enrichment System  

NASA Technical Reports Server (NTRS)

The PROPULSE 980 unit is a transportable processing plant that enriches aerospace grade hydrogen peroxide from 90% to 98% final concentration. The unit was developed by Degussa-H Is, in cooperation with Orbital, NASA Marshall Space Center, and NASA Stennis Space Center. The system is a self-contained unit that houses all of the process equipment, instrumentation and controls to perform the concentration operation nearly autonomously. It is designed to produce non-bulk quantities of 98% hydrogen peroxide. The enrichment unit design also maintains system, personnel and environmental safety during all aspects of the enrichment process and final product storage. As part of the Propulse 980 checkout and final buyoff, it will be disassembled at the Degussa-H Is Corporation plant in Theodore, AL, transported to the Stennis Space Center, reassembled and subjected to a series of checkout tests to verify design objectives have been met. This paper will summarize the basic project elements and provide an update on the present status of the project.

Boxwell, Robert; Bromley, G.; Wanger, Robert; Pauls, Dan; Maynard, Bryon; McNeal, Curtis; Dumbacher, D. L. (Technical Monitor)

2000-01-01

136

ThroopThroop -Jupiter Enrichment Henry Throop  

E-print Network

ThroopThroop - Jupiter Enrichment Henry Throop Department of Space Studies Southwest Research of Jupiter's Atmosphere from a Supernova-Contaminated Molecular Cloud #12;Throop - Jupiter Enrichment #12;Throop - Jupiter Enrichment #12;Throop - Jupiter Enrichment Jupiter:Solar abundances Enriched by 3

Throop, Henry

137

76 FR 387 - Atomic Safety and Licensing Board; AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility)  

Federal Register 2010, 2011, 2012, 2013, 2014

...Enrichment Services, LLC (Eagle Rock Enrichment Facility) December 17, 2010...December 2008 Application by AREVA Enrichment Services, LLC, (AES) seeking...operation of a gas centrifuge uranium enrichment facility--denoted as the...

2011-01-04

138

31 CFR 540.316 - Uranium enrichment.  

Code of Federal Regulations, 2014 CFR

...2014-07-01 2014-07-01 false Uranium enrichment. 540.316 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium...

2014-07-01

139

31 CFR 540.316 - Uranium enrichment.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 2013-07-01 false Uranium enrichment. 540.316 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium...

2013-07-01

140

31 CFR 540.316 - Uranium enrichment.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 2012-07-01 false Uranium enrichment. 540.316 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium...

2012-07-01

141

31 CFR 540.316 - Uranium enrichment.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Uranium enrichment. 540.316 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium...

2011-07-01

142

31 CFR 540.316 - Uranium enrichment.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Uranium enrichment. 540.316 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.316 Uranium enrichment. The term uranium...

2010-07-01

143

A Robust Infrastructure Design for Gas Centrifuge Enrichment Plant Unattended Online Enrichment Monitoring  

SciTech Connect

An online enrichment monitor (OLEM) is being developed to continuously measure the relative isotopic composition of UF6 in the unit header pipes of a gas centrifuge enrichment plant (GCEP). From a safeguards perspective, OLEM will provide early detection of a facility being misused for production of highly enriched uranium. OLEM may also reduce the number of samples collected for destructive assay and if coupled with load cell monitoring can provide isotope mass balance verification. The OLEM design includes power and network connections for continuous monitoring of the UF6 enrichment and state of health of the instrument. Monitoring the enrichment on all header pipes at a typical GCEP could require OLEM detectors on each of the product, tails, and feed header pipes. If there are eight process units, up to 24 detectors may be required at a modern GCEP. Distant locations, harsh industrial environments, and safeguards continuity of knowledge requirements all place certain demands on the network robustness and power reliability. This paper describes the infrastructure and architecture of an OLEM system based on OLEM collection nodes on the unit header pipes and power and network support nodes for groupings of the collection nodes. A redundant, self-healing communications network, distributed backup power, and a secure communications methodology. Two candidate technologies being considered for secure communications are the Object Linking and Embedding for Process Control Unified Architecture cross-platform, service-oriented architecture model for process control communications and the emerging IAEA Real-time And INtegrated STream-Oriented Remote Monitoring (RAINSTORM) framework to provide the common secure communication infrastructure for remote, unattended monitoring systems. The proposed infrastructure design offers modular, commercial components, plug-and-play extensibility for GCEP deployments, and is intended to meet the guidelines and requirements for unattended and remotely monitored safeguards systems.

Younkin, James R [ORNL; Rowe, Nathan C [ORNL; Garner, James R [ORNL

2012-01-01

144

10 CFR Appendix G to Part 110 - Illustrative List of Plasma Separation Enrichment Plant Equipment and Components Under NRC Export...  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Illustrative List of Plasma Separation Enrichment Plant Equipment...G to Part 110—Illustrative List of Plasma Separation Enrichment Plant Equipment...Licensing Authority Note —In the plasma separation process, a plasma...

2010-01-01

145

10 CFR Appendix G to Part 110 - Illustrative List of Plasma Separation Enrichment Plant Equipment and Components Under NRC Export...  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Illustrative List of Plasma Separation Enrichment Plant Equipment...G to Part 110—Illustrative List of Plasma Separation Enrichment Plant Equipment...Licensing Authority Note —In the plasma separation process, a plasma...

2011-01-01

146

10 CFR Appendix G to Part 110 - Illustrative List of Plasma Separation Enrichment Plant Equipment and Components Under NRC Export...  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Illustrative List of Plasma Separation Enrichment Plant Equipment...G to Part 110—Illustrative List of Plasma Separation Enrichment Plant Equipment...Licensing Authority Note —In the plasma separation process, a plasma...

2012-01-01

147

10 CFR Appendix G to Part 110 - Illustrative List of Plasma Separation Enrichment Plant Equipment and Components Under NRC Export...  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Illustrative List of Plasma Separation Enrichment Plant Equipment...G to Part 110—Illustrative List of Plasma Separation Enrichment Plant Equipment...Licensing Authority Note —In the plasma separation process, a plasma...

2013-01-01

148

10 CFR Appendix G to Part 110 - Illustrative List of Plasma Separation Enrichment Plant Equipment and Components Under NRC Export...  

Code of Federal Regulations, 2014 CFR

...2014-01-01 false Illustrative List of Plasma Separation Enrichment Plant Equipment...G to Part 110—Illustrative List of Plasma Separation Enrichment Plant Equipment...Licensing Authority Note: In the plasma separation process, a plasma...

2014-01-01

149

Post-AGB stars in the SMC as tracers of stellar evolution: the extreme s-process enrichment of the 21 ?m star J004441.04-732136.4  

NASA Astrophysics Data System (ADS)

Context. This paper is part of a larger project in which we want to focus on the still poorly understood asymptotic giant branch (AGB) third dredge-up processes and associated s-process nucleosynthesis. Aims: We confront accurate spectral abundance analyses of post-AGB stars in both the Magellanic Clouds, to state-of-the-art AGB model predictions. With this comparison we aim at improving our understanding of the 3rd dredge-up phenomena and their dependencies on initial mass and metallicity. Methods: Because of the well constrained distance with respect to Galactic post-AGB stars, we choose an extra-galactic post-AGB star for this contribution, namely the only known 21 ?m object of the Small Magellanic Cloud (SMC): J004441.04-732136.4. We used optical UVES spectra to perform an accurate spectral abundance analysis. With photometric data of multiple catalogues we construct a spectral energy distribution (SED) and perform a variability analysis. The results are then compared to predictions of tailored theoretical chemical AGB evolutionary models for which we used two evolution codes. Results: Spectral abundance results reveal J004441.04-732136.4 to be one of the most s-process enriched objects found up to date, while the photospheric C/O ratio of 1.9 ± 0.7, shows the star is only modestly C-rich. J004441.04-732136.4 also displays a low [Fe/H] = -1.34 ± 0.32, which is significantly lower than the mean metallicity of the SMC. From the SED, a luminosity of 7600 ± 200 L? is found, together with E(B - V) = 0.64 ± 0.02. According to evolutionary post-AGB tracks, the initial mass should be ?1.3 M?. The photometric variability shows a clear period of 97.6 ± 0.3 days. The detected C/O as well as the high s-process overabundances (e.g. [Y/Fe] = 2.15, [La/Fe] = 2.84) are hard to reconcile with the predictions. The chemical models also predict a high Pb abundance, which is not compatible with the detected spectrum, and a very high 12C/13C, which is not yet constrained by observations. The predictions are only marginally dependent on the evolution codes used. Conclusions: By virtue of their spectral types, favourable bolometric corrections as well as their constrained distances, post-AGB stars in external galaxies offer unprecedented tests to AGB nucleosynthesis and dredge-up predictions. We focus here on one object J004441.04-732136.4, which is the only known 21 ?m source of the SMC. We show that our theoretical predictions match the s-process distribution, but fail in reproducing the detected high overabundances and predict a high Pb abundance which is not detected. Additionally, there remain serious problems in explaining the observed pulsational properties of this source. Based on observations collected with the Very Large Telescope at the ESO Paranal Observatory (Chili) of programme number 084.D-0932.Table 5 is available in electronic form at http://www.aanda.org

De Smedt, K.; Van Winckel, H.; Karakas, A. I.; Siess, L.; Goriely, S.; Wood, P. R.

2012-05-01

150

Advanced technology for enrichment monitoring for gas centrifuge enrichment plants  

Microsoft Academic Search

We report our developments of the next generation of uranium enrichment monitoring technology for gas centrifuge enrichment\\u000a plants (GCEPs). The main challenge presented by current technology is the need for periodic replacement of the short half-life\\u000a (1.27 year) 109Cd transmission source. We report on a transmission source at the 22.1 keV K-edge of ruthenium based on an X-ray tube with\\u000a a “notch”

K. D. Ianakiev; J. M. Goda; T. R. Hill; C. E. Moss; J. J. Ong; M. T. Paffett; R. F. Parker; M. T. Swinhoe

2009-01-01

151

Peak fitting applied to low-resolution enrichment measurements  

SciTech Connect

Materials accounting at bulk processing facilities that handle low enriched uranium consists primarily of weight and uranium enrichment measurements. Most low enriched uranium processing facilities draw separate materials balances for each enrichment handled at the facility. The enrichment measurement determines the isotopic abundance of the {sup 235}U, thereby determining the proper strata for the item, while the weight measurement generates the primary accounting value for the item. Enrichment measurements using the passive gamma radiation from uranium were developed for use in US facilities a few decades ago. In the US, the use of low-resolution detectors was favored because they cost less, are lighter and more robust, and don`t require the use of liquid nitrogen. When these techniques were exported to Europe, however, difficulties were encountered. Two of the possible root causes were discovered to be inaccurate knowledge of the container wall thickness and higher levels of minor isotopes of uranium introduced by the use of reactor returns in the enrichment plants. the minor isotopes cause an increase in the Compton continuum under the 185.7 keV assay peak and the observance of interfering 238.6 keV gamma rays. The solution selected to address these problems was to rely on the slower, more costly, high-resolution gamma ray detectors when the low-resolution method failed. Recently, these gamma ray based enrichment measurement techniques have been applied to Russian origin material. The presence of interfering gamma radiation from minor isotopes was confirmed. However, with the advent of fast portable computers, it is now possible to apply more sophisticated analysis techniques to the low-resolution data in the field. Explicit corrections for Compton background, gamma rays from {sup 236}U daughters, and the attenuation caused by thick containers can be part of the least squares fitting routine. Preliminary results from field measurements in Kazakhstan will be discussed.

Bracken, D.; McKown, T.; Sprinkle, J.K. Jr. [Los Alamos National Lab., NM (United States); Gunnink, R. [Lawrence Livermore National Lab., CA (United States); Kartoshov, M.; Kuropatwinski, J.; Raphina, G.; Sokolov, G. [Ulba Metallurgical Facility, Ust-Kamenogorsk (Kazakhstan)

1998-12-01

152

Musicals Enrich Middle School Programs  

ERIC Educational Resources Information Center

An enriching fine arts program has long been advocated as an essential element of an effective middle school program. The vocal music program at Pleasant Hill (Missouri) Middle School supports student growth and development beyond the regular classroom. It supports students' existing skills and talents and provides opportunities for them to…

Thomas, Douglas D.; North, Rita

2005-01-01

153

Enrichment Tours in Physical Education.  

ERIC Educational Resources Information Center

Enrichment tours designed to heighten interest and enhance the breadth and depth of learning a lifetime sport are encouraged. A tour of the Florida Keys and Bahama Islands for sailing and diving taken by students from Mankato State University is described. (JMF)

McCarthy, Jean

1980-01-01

154

Enriching SDL Specifications with MSCs *  

E-print Network

&D, Lannion, France Abstract Software systems evolve through addition of new behaviors and new components to the existing behavior and architecture. In this paper, we address the issue of enriching automatically SDL specifications with new behaviors specified with MSCs. The new behaviors should not inhibit (invalidate) existing

Khendek, Ferhat

155

77 FR 13367 - General Electric-Hitachi Global Laser Enrichment, LLC, Proposed Laser-Based Uranium Enrichment...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Enrichment, LLC, Proposed Laser-Based Uranium Enrichment Facility, Wilmington, NC...Global Laser Enrichment, LLC (GLE) Uranium Enrichment Facility. On June 26, 2009...and decommissioning of a laser-based uranium enrichment facility (the...

2012-03-06

156

Preparation of biomembrane by immobilizing enriched ammonia-oxidizing bacteria (AOB) in polyvinyl alcohol (PVA) for biosensor  

Microsoft Academic Search

A biomembrane that was used to make a biosensor for detecting inhibitor of ammoia oxidation was prepared by entrapping enriched ammonia-oxidizing bacteria (AOB) in polyvinyl alcohol (PVA). AOB were enriched by fed batch cultivation with using return activated sludge from A 2 \\/O process as seed. Enrichment of AOB was confirmed by denaturing gradient gel electrophoresis (DGGE) analysis. The optimum

Rong Cui; Jinling Li; Ke Zhang; Jinglong Han

2011-01-01

157

Conversion and Blending Facility highly enriched uranium to low enriched uranium as oxide. Revision 1  

SciTech Connect

This Conversion and Blending Facility (CBF) will have two missions: (1) convert HEU materials into pure HEU oxide and (2) blend the pure HEU oxide with depleted and natural uranium oxide to produce an LWR grade LEU product. The primary emphasis of this blending operation will be to destroy the weapons capability of large, surplus stockpiles of HEU. The blended LEU product can only be made weapons capable again by the uranium enrichment process. To the extent practical, the chemical and isotopic concentrations of blended LEU product will be held within the specifications required for LWR fuel. Such blended LEU product will be offered to the United States Enrichment Corporation (USEC) to be sold as feed material to the commercial nuclear industry. Otherwise, blended LEU will be produced as a waste suitable for storage or disposal.

NONE

1995-07-05

158

Conversion and Blending Facility Highly enriched uranium to low enriched uranium as uranium hexafluoride. Revision 1  

SciTech Connect

This report describes the Conversion and Blending Facility (CBF) which will have two missions: (1) convert surplus HEU materials to pure HEU UF{sub 6} and a (2) blend the pure HEU UF{sub 6} with diluent UF{sub 6} to produce LWR grade LEU-UF{sub 6}. The primary emphasis of this blending be to destroy the weapons capability of large, surplus stockpiles of HEU. The blended LEU product can only be made weapons capable again by the uranium enrichment process. The chemical and isotopic concentrations of the blended LEU product will be held within the specifications required for LWR fuel. The blended LEU product will be offered to the United States Enrichment Corporation (USEC) to be sold as feed material to the commercial nuclear industry.

NONE

1995-07-05

159

New generation enrichment monitoring technology for gas centrifuge enrichment plants  

Microsoft Academic Search

We report our progress toward development of new generation on-line enrichment monitoring technology for UF6 gas centrifuge plants based on a transmission source and a NaI spectrometer. We use an X-ray tube with transmission filters instead of a decaying isotopic transmission source to eliminate the costly replacement of this source. The UF6 gas density measurement is based on the energy

Kiril D Ianakiev; Boian Alexandrov; B. D. Boyer; T. R. Hill; D. W. MacArthur; T. A. Marks; C. E. Moss; B. P. Nolen; M. T. Paffett; G. A. Sheppard; M. T. Swinhoe; E. Calvin; Sheppard; A. Gregory; Swinhoe; T. Martyn

2008-01-01

160

The difficult mountain: enriched composition in adjective–noun phrases  

PubMed Central

When readers need to go beyond the straightforward compositional meaning of a sentence (i.e., when enriched composition is required), costly additional processing is the norm. However, this conclusion is based entirely on research that has looked at enriched composition between two phrases or within the verb phrase (e.g., the verb and its complement in … started the book …) where there is a discrepancy between the semantic expectations of the verb and the semantics of the noun. We carried out an eye-tracking experiment investigating enriched composition within a single noun phrase, as in the difficult mountain. As compared with adjective–noun phrases that allow a straightforward compositional interpretation (the difficult exercise), the coerced phrases were more difficult to process. These results indicate that coercion effects can be found in the absence of a typing violation and within a single noun phrase. PMID:21826403

Pickering, Martin J.; McElree, Brian

2012-01-01

161

Enrichment demand boosts SWU prices  

SciTech Connect

The enrichment market is picking up significantly on very brisk demand. US utilities, which normally purchase material nine months to a year ahead of time, are already hitting the market to fill their 1996 requirements. In June, two non-US utilities, one European entity and a US utility bought SWUs, the entity in an off-market deal. But that doesn't tell the whole story. Three other US utilities entered the market during the month. Meanwhile, we count 13 more utilities getting ready to hit the market for more than 4 million SWUs. Why the surge in demand Utilities, uncertain of the role to be played by the new US Enrichment Corp. and seeking to take advantage of low interest rates, are implementing buy and hold strategies. As a result, the upper end of NUKEM's SWU price range inched up to $78. The lower end dipped to $67 based on the European deal.

Not Available

1993-07-01

162

Student Science Enrichment Training Program  

SciTech Connect

Funds are requested for the science enrichment training program (emphasis on chemistry and computer science), which will be held at Claflin College during the 1990 and 1991 summers, concomitant with summer school. The thirty participants will include high school students and some college freshmen; the students will come from rural South Carolina schools with limited science and computer facilities. Focus will be on high ability minority students.

Sandhu, S.S.

1990-12-31

163

Implementing Enrichment Clusters in Elementary Schools: Lessons Learned  

ERIC Educational Resources Information Center

Enrichment clusters offer a way for schools to encourage a high level of learning as students and adults work together to develop a product, service, or performance by applying advanced knowledge and authentic processes to real-world problems. This study utilized a qualitative research design to examine the perceptions and experiences of two…

Fiddyment, Gail E.

2014-01-01

164

Defining and Building an Enriched Learning and Information Environment.  

ERIC Educational Resources Information Center

Discusses the development of an Enriched Learning and Information Environment (ELIE). Highlights include technology-based and theory-based frameworks for defining ELIEs; a socio-technical definition; a conceptual prototype; a participatory design process, including iterative design through rapid prototyping; and design issues for technology…

Goodrum, David A.; And Others

1993-01-01

165

ENRICHMENT OF PCBS IN LAKE MICHIGAN SURFACE FILMS  

EPA Science Inventory

The processes of exchange of PCBs and related organics at the surface of large bodies of water such as the Great Lakes are unavoidably linked to the unique properties of surface films. The authors have observed a 3 to 8 fold enrichment of PCB over underlying water in surface film...

166

Availability of enriched stable isotopes: present status and future prospects  

SciTech Connect

The Electromagnetic Isotope Enrichment Facility (EMIEF) is currently used to produce 225 enriched stable isotopes of 50 elements. Among these are included most of the known elements with stable isotopes except for the noble gases, certain light elements, monisotopic elements, etc. The EMIEF can also be used to produce enriched samples of radioactive species, most notably the isotopes of uranium and plutonium. These enriched materials are placed in either the Sales Inventory of in the Research Materials Collection (RMC). The materials in the Sales Inventory are for sale to anyone on a first come, first served basis. Prices in the most recent catalog range from $0.05/mg for 99.8% /sup 140/Ce to $1,267/mg for 98.5% /sup 176/Lu. The materials in the RMC are made available to US researchers (or groups that include a US investigator) on a loan basis for use in non-destructive experiments and applications. In addition, certain samples have been provided to European investigators for cross-section studies through the auspices of EURATOM and the European-American Nuclear Data Committee. The status of the enriched isotopes included in the Sales Inventory is tabulated where isotopes are listed that are either not available or are in insufficient quantity or quality to meet current requests, as of 6/30/86. These can be summarized in the following subcategories: isotopes with zero inventory (22), Isotopes of insufficient quantity (17), and isotopes with insufficient enrichment quality (10). Of these 49 species, the supplies of 10 will be replenished by the scheduled FY86 enrichments in process (isotopes of bromine, calcium, nickel, potassium, rubidium, and strontium). In Table 3 are listed isotopes where the current inventory is less than the average annual sales level for the past five years. There are 47 isotopes listed, representing 25 different elements. Thus, there exists considerable potential for a substantial increase in the number of isotopes with zero inventory.

Hoff, R.W.

1986-09-18

167

Free-Air CO2 Enrichment (FACE) Experiment PRINCIPAL INVESTIGATOR: Richard J. Norby  

E-print Network

Free-Air CO2 Enrichment (FACE) project is to understand how the eastern deciduous forest and related processes in a 12-year FACE experiment in a deciduous Liquidambar styraciflua (sweetgum) forest will be affected by CO2 enrichment of the atmosphere and the feed- backs from the forest to the atmosphere

168

The paradox of enrichment in phytoplankton by induced competitive interactions  

PubMed Central

The biodiversity loss of phytoplankton with eutrophication has been reported in many aquatic ecosystems, e.g., water pollution and red tides. This phenomenon seems similar, but different from the paradox of enrichment via trophic interactions, e.g., predator-prey systems. We here propose the paradox of enrichment by induced competitive interactions using multiple contact process (a lattice Lotka-Volterra competition model). Simulation results demonstrate how eutrophication invokes more competitions in a competitive ecosystem resulting in the loss of phytoplankton diversity in ecological time. The paradox is enhanced under local interactions, indicating that the limited dispersal of phytoplankton reduces interspecific competition greatly. Thus, the paradox of enrichment appears when eutrophication destroys an ecosystem either by elevated interspecific competition within a trophic level and/or destabilization by trophic interactions. Unless eutrophication due to human activities is ceased, the world's aquatic ecosystems will be at risk. PMID:24089056

Tubay, Jerrold M.; Ito, Hiromu; Uehara, Takashi; Kakishima, Satoshi; Morita, Satoru; Togashi, Tatsuya; Tainaka, Kei-ichi; Niraula, Mohan P.; Casareto, Beatriz E.; Suzuki, Yoshimi; Yoshimura, Jin

2013-01-01

169

Increasing the performance of tritium analysis by electrolytic enrichment.  

PubMed

Several improvements are described for the existing tritium enrichment system at the Isotope Hydrology Laboratory of the International Atomic Energy Agency for processing natural water samples. The improvements include a simple method for pretreatment of electrolytic cells to ensure a high tritium separation factor, an improved design of the exhaust system for explosive gases, and a vacuum distillation line for faster initial preparation of water samples for electrolytic enrichment and for tritium analysis. Achievements included the reduction of variation of individual enrichment parameters of all cells to less than 1% and an improvement of 50% of the stability of the background mean. It resulted in an improved detection limit of less than 0.4 TU (at 2s), important for application of tritium measurements in the future at low concentration levels, and resulted in measurement precisions of+/-0.2 TU and+/-0.15 TU for liquid scintillation counting and for gas proportional counting, respectively. PMID:20183225

Groning, M; Auer, R; Brummer, D; Jaklitsch, M; Sambandam, C; Tanweer, A; Tatzber, H

2009-06-01

170

Environmental enrichment for primates in laboratories  

NASA Astrophysics Data System (ADS)

Environmental enrichment is a critical component of Refinement, one of the 3Rs underlying humane experimentation on animals. In this paper I discuss why primates housed in laboratories, which often have constraints of space and study protocols, are a special case for enrichment. I outline a framework for categorising the different types of enrichment, using the marmoset as a case study, and summarise the methods used to determine what animals want/prefer. I briefly review the arguments that enrichment does not negatively affect experimental outcomes. Finally I focus on complexity and novelty, choice and control, the underlying features of enrichment that makes it successful, and how combined with a thorough understanding of natural history we can put effective enrichment into practice in laboratories. Throughout the paper I emphasise the need to evaluate enrichment to ensure it is having the desired effect.

Buchanan-Smith, H. M.

2010-06-01

171

Microfluidic platform for negative enrichment of circulating tumor cells.  

PubMed

Negative enrichment is the preferred approach for tumor cell isolation as it does not rely on biomarker expression. However, size-based negative enrichment methods suffer from well-known recovery/purity trade-off. Non-size based methods have a number of processing steps that lead to compounded cell loss due to extensive sample processing and handling which result in a low recovery efficiency. We present a method that performs negative enrichment in two steps from 2 ml of whole blood in a total assay processing time of 60 min. This negative enrichment method employs upstream immunomagnetic depletion to deplete CD45-positive WBCs followed by a microfabricated filter membrane to perform chemical-free RBC depletion and target cells isolation. Experiments of spiking two cell lines, MCF-7 and NCI-H1975, in the whole blood show an average of >90 % cell recovery over a range of spiked cell numbers. We also successfully recovered circulating tumor cells from 15 cancer patient samples. PMID:24668439

Sajay, Bhuvanendran Nair Gourikutty; Chang, Chia-Pin; Ahmad, Hamizah; Khuntontong, Puttachat; Wong, Chee Chung; Wang, Zhiping; Puiu, Poenar Daniel; Soo, Ross; Rahman, Abdur Rub Abdur

2014-08-01

172

Defining the needs for gas centrifuge enrichment plants advanced safeguards  

SciTech Connect

Current safeguards approaches used by the International Atomic Energy Agency (IAEA) at gas centrifuge enrichment plants (GCEPs) need enhancement in order to verify declared low-enriched (LEU) production, detect undeclared LEU production and detect highly enriched uranium (HEU) production with adequate detection probability using nondestructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and {sup 235}U enrichment of declared UF{sub 6} containers used in the process of enrichment at GCEPs. In verifying declared LEU production, the inspectors also take samples for off-site destructive assay (DA) which provide accurate data, with 0.1% to 0.5% measurement uncertainty, on the enrichment of the UF{sub 6} feed, tails, and product. However, taking samples of UF{sub 6} for off-site analysis is a much more labor and resource intensive exercise for the operator and inspector. Furthermore, the operator must ship the samples off-site to the IAEA laboratory which delays the timeliness of results and interruptions to the continuity of knowledge (CofK) of the samples during their storage and transit. This paper contains an analysis of possible improvements in unattended and attended NDA systems such as process monitoring and possible on-site analysis of DA samples that could reduce the uncertainty of the inspector's measurements and provide more effective and efficient IAEA GCEPs safeguards. We also introduce examples advanced safeguards systems that could be assembled for unattended operation.

Boyer, Brian David [Los Alamos National Laboratory; Erpenbeck, Heather H [Los Alamos National Laboratory; Miller, Karen A [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Ianakiev, Kiril [Los Alamos National Laboratory; Marlowe, Johnna B [Los Alamos National Laboratory

2010-01-01

173

Boron Enrichment in Martian Clay  

PubMed Central

We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

Nagashima, Kazuhide; Freeland, Stephen J.

2013-01-01

174

Boron enrichment in martian clay.  

PubMed

We have detected a concentration of boron in martian clay far in excess of that in any previously reported extra-terrestrial object. This enrichment indicates that the chemistry necessary for the formation of ribose, a key component of RNA, could have existed on Mars since the formation of early clay deposits, contemporary to the emergence of life on Earth. Given the greater similarity of Earth and Mars early in their geological history, and the extensive disruption of Earth's earliest mineralogy by plate tectonics, we suggest that the conditions for prebiotic ribose synthesis may be better understood by further Mars exploration. PMID:23762242

Stephenson, James D; Hallis, Lydia J; Nagashima, Kazuhide; Freeland, Stephen J

2013-01-01

175

31 CFR 540.306 - Highly Enriched Uranium (HEU).  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false Highly Enriched Uranium (HEU). 540.306 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.306 Highly Enriched Uranium (HEU). The term highly enriched...

2011-07-01

176

31 CFR 540.306 - Highly Enriched Uranium (HEU).  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false Highly Enriched Uranium (HEU). 540.306 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.306 Highly Enriched Uranium (HEU). The term highly enriched...

2013-07-01

177

31 CFR 540.306 - Highly Enriched Uranium (HEU).  

Code of Federal Regulations, 2014 CFR

...2014-07-01 false Highly Enriched Uranium (HEU). 540.306 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.306 Highly Enriched Uranium (HEU). The term highly enriched...

2014-07-01

178

31 CFR 540.306 - Highly Enriched Uranium (HEU).  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Highly Enriched Uranium (HEU). 540.306 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.306 Highly Enriched Uranium (HEU). The term highly enriched...

2010-07-01

179

31 CFR 540.308 - Low Enriched Uranium (LEU).  

Code of Federal Regulations, 2013 CFR

... 2013-07-01 false Low Enriched Uranium (LEU). 540.308 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.308 Low Enriched Uranium (LEU). The term low enriched...

2013-07-01

180

31 CFR 540.308 - Low Enriched Uranium (LEU).  

Code of Federal Regulations, 2014 CFR

... 2014-07-01 false Low Enriched Uranium (LEU). 540.308 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.308 Low Enriched Uranium (LEU). The term low enriched...

2014-07-01

181

31 CFR 540.308 - Low Enriched Uranium (LEU).  

Code of Federal Regulations, 2011 CFR

... 2011-07-01 false Low Enriched Uranium (LEU). 540.308 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.308 Low Enriched Uranium (LEU). The term low enriched...

2011-07-01

182

31 CFR 540.306 - Highly Enriched Uranium (HEU).  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false Highly Enriched Uranium (HEU). 540.306 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.306 Highly Enriched Uranium (HEU). The term highly enriched...

2012-07-01

183

31 CFR 540.308 - Low Enriched Uranium (LEU).  

Code of Federal Regulations, 2012 CFR

... 2012-07-01 false Low Enriched Uranium (LEU). 540.308 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.308 Low Enriched Uranium (LEU). The term low enriched...

2012-07-01

184

31 CFR 540.308 - Low Enriched Uranium (LEU).  

Code of Federal Regulations, 2010 CFR

... 2010-07-01 false Low Enriched Uranium (LEU). 540.308 Section 540...DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS...Definitions § 540.308 Low Enriched Uranium (LEU). The term low enriched...

2010-07-01

185

Production of oxygen enriched air by rapid pressure swing adsorption  

Microsoft Academic Search

A novel rapid pressure swing adsorption (RPSA) process is described for production of 25–50% oxygen enriched air. The embodiment consists of one or more pairs of adsorbent layers contained in a single adsorption vessel. The layers undergo simultaneous pressurization-adsorption and simultaneous depressurization-purge steps. A total cycle time of 6–20 seconds is used. The process yields a very large specific oxygen

S. Sircar; B. F. Hanley

1995-01-01

186

Unattended Environmental Sampling and Laser-based Enrichment Assay for Detection of Undeclared HEU Production in Enrichment Plants  

SciTech Connect

Nuclear power is enjoying rapid growth as government energy policies and public demand shift toward carbon neutral energy production. Accompanying the growth in nuclear power is the requirement for increased nuclear fuel production, including a significant expansion in uranium enrichment capacity. Essential to the success of the nuclear energy renaissance is the development and implementation of sustainable, proliferation-resistant nuclear power generation. Unauthorized production of highly enriched uranium (HEU) remains the primary proliferation concern for modern gaseous centrifuge enrichment plants (GCEPs). While to date there has been no indication of declared, safeguarded GCEPs producing HEU, the massive separative work unit (SWU) processing power of modern GCEPs presents a significant latent risk of nuclear breakout and suggests the need for more timely detection of potential facility misuse. The Pacific Northwest National Laboratory is developing an unattended safeguards instrument, combining continuous aerosol particulate collection with uranium isotope assay, to provide timely HEU detection within a GCEP. This approach is based on laser vaporization of aerosol particulates, followed by laser spectroscopy to characterize the uranium enrichment level. We demonstrate enrichment assay, with relative isotope abundance uncertainty <5%, on individual micron-sized particles that are trace components within a mixture ‘background’ particles

Anheier, Norman C.; Bushaw, Bruce A.

2010-04-15

187

77 FR 14838 - General Electric-Hitachi Global Laser Enrichment LLC, Commercial Laser-Based Uranium Enrichment...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Enrichment LLC, Commercial Laser-Based Uranium Enrichment Facility, Wilmington, North...authorize construction of a laser-based uranium enrichment facility and possession and...material, and SNM in a laser-based uranium enrichment facility. Revisions to...

2012-03-13

188

75 FR 10525 - In the Matter of: AREVA Enrichment Services, LLC (Eagle Rock Enrichment Facility) and All Other...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Enrichment Services, LLC (Eagle Rock Enrichment Facility) and All Other Persons...Effective Immediately) I AREVA Enrichment Services, LLC (AES), has...it to construct and operate a uranium enrichment facility in Bonneville...

2010-03-08

189

76 FR 34103 - In the Matter of Areva Enrichment Services, LLC (Eagle Rock Enrichment Facility); Notice of...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Enrichment Services, LLC (Eagle Rock Enrichment Facility); Notice of Hearing...December 2008 application by AREVA Enrichment Services, LLC (AES) seeking...operation of a gas centrifuge uranium enrichment facility--denoted as the...

2011-06-10

190

Pressure swing adsorption cycles for improved solvent vapor enrichment  

SciTech Connect

A pressure swing adsorption (PSA)-solvent vapor recovery (SVR) process simulator was used to investigate new PSA cycle configurations designed for higher solvent vapor enrichment. These cycles were modifications of the four-step Skarstrom cycle used commercially for PSA-SVR and include the addition of a cocurrent blowdown step, and combinations of cocurrent blowdown and continuous/batch reflux steps. The recovery of gasoline vapor from tank filling operations was simulated with n-butane, n-heptane, and nitrogen as representatives of the light and heavy components in gasoline vapor, and carrier gas, respectively. Adding a cocurrent blowdown step increased the solvent vapor enrichment, depending mainly on the step ending pressure, not the step time. Both the continuous and batch reflux steps also increased the solvent vapor enrichment, but at the expense of an increased bed capacity factor. For similar increases in the solvent vapor enrichment, batch reflux led to significantly smaller bed capacity factors compared to continuous reflux and was thus superior for PSA-SVR. Overall PSA-SVR process performance improved markedly by adding cocurrent blowdown and batch reflux steps compared to the conventional four-step cycle.

Liu, Y.; Ritter, J.A.; Kaul, B.K.

2000-03-01

191

Interaction modes and approaches to glycopeptide and glycoprotein enrichment.  

PubMed

Protein glycosylation has received increased attention for its critical role in cell biology and diseases. Developing new methodologies to discern phenotype-dependent glycosylation will not only elucidate the mechanistic aspects of cell signaling cascades but also accelerate biomarker discovery for disease diagnosis or prognosis. In the analytical pipeline, enrichment at either the protein or peptide level is the most critical prerequisite for analyzing heterogeneous glycan composition, linkage, site occupancy and carrier proteins. Because the critical factor for choosing a suitable enrichment method is primarily a particular technique's selectivity and affinity towards target glycoproteins/glycopeptides, it is important to fully understand the working principles for the different approaches. For mechanistic insight into the enrichment protocol, we focused on the fundamental chemical and physical processes for the commonly used approaches based on: (a) glycan/peptide physicochemical properties (hydrophilic interactions, chelation/coordination chemistry) and (b) glycan-specific recognition (lectin-based affinity, covalent bond formation by hydrazide/boronic acid). Various interaction modes, such as hydrogen bonding, van der Waals interaction, multivalency, and metal- or water-mediated stabilization, are discussed in detail. In addition, we will review the design of and modifications to such methods, hyphenated approaches, and glycoproteomic applications. Finally, we will outline challenges to existing strategies and offer novel proposals for glycoproteome enrichment. PMID:24336240

Chen, Chen-Chun; Su, Wan-Chih; Huang, Bao-Yu; Chen, Yu-Ju; Tai, Hwan-Ching; Obena, Rofeamor P

2014-02-21

192

Enrichment Assay Methods Development for the Integrated Cylinder Verification System  

SciTech Connect

International Atomic Energy Agency (IAEA) inspectors currently perform periodic inspections at uranium enrichment plants to verify UF6 cylinder enrichment declarations. Measurements are typically performed with handheld high-resolution sensors on a sampling of cylinders taken to be representative of the facility's entire product-cylinder inventory. Pacific Northwest National Laboratory (PNNL) is developing a concept to automate the verification of enrichment plant cylinders to enable 100 percent product-cylinder verification and potentially, mass-balance calculations on the facility as a whole (by also measuring feed and tails cylinders). The Integrated Cylinder Verification System (ICVS) could be located at key measurement points to positively identify each cylinder, measure its mass and enrichment, store the collected data in a secure database, and maintain continuity of knowledge on measured cylinders until IAEA inspector arrival. The three main objectives of this FY09 project are summarized here and described in more detail in the report: (1) Develop a preliminary design for a prototype NDA system, (2) Refine PNNL's MCNP models of the NDA system, and (3) Procure and test key pulse-processing components. Progress against these tasks to date, and next steps, are discussed.

Smith, Leon E.; Misner, Alex C.; Hatchell, Brian K.; Curtis, Michael M.

2009-10-22

193

Isotopic enrichment of fuels for D-T fusion reactors  

SciTech Connect

Isotopic enrichment scenarios using cryogenic distillation were developed for a near-term D-T burning fusion-reactor design (ETF) as well as for a commercial fusion-reactor design (STARFIRE). The analytical results of studies of spent-fuel reprocessing for ETF show that isotopic enrichment can be carried out to meet fuel-purity requirements by a system consisting of a 5-column distillation cascade and two chemical equilibrators. For STARFIRE, the analytical results show that, for a fixed number of columns and chemical equilibrators in a reprocessing syste, the compositions of the recycle streams depend strongly on whether the two fuel streams (plasma exhaust and blanket) are processed separately or mixed and then processed as a single stream.

Misra, B.; Clemmer, R.G.; Finn, P.A.

1981-01-01

194

Inoculation stress hypothesis of environmental enrichment.  

PubMed

One hallmark of psychiatric conditions is the vast continuum of individual differences in susceptibility vs. resilience resulting from the interaction of genetic and environmental factors. The environmental enrichment paradigm is an animal model that is useful for studying a range of psychiatric conditions, including protective phenotypes in addiction and depression models. The major question is how environmental enrichment, a non-drug and non-surgical manipulation, can produce such robust individual differences in such a wide range of behaviors. This paper draws from a variety of published sources to outline a coherent hypothesis of inoculation stress as a factor producing the protective enrichment phenotypes. The basic tenet suggests that chronic mild stress from living in a complex environment and interacting non-aggressively with conspecifics can inoculate enriched rats against subsequent stressors and/or drugs of abuse. This paper reviews the enrichment phenotypes, mulls the fundamental nature of environmental enrichment vs. isolation, discusses the most appropriate control for environmental enrichment, and challenges the idea that cortisol/corticosterone equals stress. The intent of the inoculation stress hypothesis of environmental enrichment is to provide a scaffold with which to build testable hypotheses for the elucidation of the molecular mechanisms underlying these protective phenotypes and thus provide new therapeutic targets to treat psychiatric/neurological conditions. PMID:25449533

Crofton, Elizabeth J; Zhang, Yafang; Green, Thomas A

2015-02-01

195

Enrichment Monitor for 235U Fuel Tubes  

SciTech Connect

This report describes the performance of this prototype y-monitor of 235 Uranium enrichment. In this proposed method y-rates associated with 235U and 232U are correlated with enrichment. Instrumentation for appraising fuel tubes with this method has been assembled and tested.

Winn, W.G.

2001-08-22

196

Pressure swing adsorption cycles for improved solvent vapor enrichment  

Microsoft Academic Search

A pressure swing adsorption (PSA)-solvent vapor recovery (SVR) process simulator was used to investigate new PSA cycle configurations designed for higher solvent vapor enrichment. These cycles were modifications of the four-step Skarstrom cycle used commercially for PSA-SVR and include the addition of a cocurrent blowdown step, and combinations of cocurrent blowdown and continuous\\/batch reflux steps. The recovery of gasoline vapor

Yujun Liu; James A. Ritter; Bal K. Kaul

2000-01-01

197

Strong tin enrichment in a pegmatite-forming melt  

Microsoft Academic Search

To investigate processes of magmatic tin enrichment and cassiterite deposition, we studied the abundances of major, trace,\\u000a and volatile elements in a large number of rehomogenized silicate melt inclusions in quartz and topaz from a pegmatite body\\u000a at the Ehrenfriedersdorf Sn–W deposit. This deposit is associated with evolved Variscan granites of the central Erzgebirge,\\u000a southeast Germany. The melt inclusions are

R. Thomas; J. D. Webster

2000-01-01

198

Mortality among uranium enrichment workers  

SciTech Connect

A retrospective cohort mortality study was conducted on workers at the Portsmouth Uranium Enrichment facility in Pike County, Ohio, in response to a request from the Oil, Chemical and Atomic Workers International Local 3-689 for information on long-term health effects. Primary hazards included inhalation exposure to uranyl fluoride containing uranium-235 and uranium-234, technetium-99 compounds, and hydrogen-fluoride. Uranium-238 presented a nephrotoxic hazard. Statistically significant mortality deficits based on U.S. death rates were found for all causes, accidents, violence, and diseases of nervous, circulatory, respiratory, and digestive systems. Standardized mortality rates were 85 and 54 for all malignant neoplasms and for other genitourinary diseases, respectively. Deaths from stomach cancer and lymphatic/hematopoietic cancers were insignificantly increased. A subcohort selected for greatest potential uranium exposure has reduced deaths from these malignancies. Insignificantly increased stomach cancer mortality was found after 15 years employment and after 15 years latency. Routine urinalysis data suggested low internal uranium exposures.

Brown, D.P.; Bloom, T.

1987-01-01

199

Student science enrichment training program  

SciTech Connect

This is a report on the Student Science Enrichment Training Program, with special emphasis on chemical and computer science fields. The residential summer session was held at the campus of Claflin College, Orangeburg, SC, for six weeks during 1993 summer, to run concomitantly with the college`s summer school. Fifty participants selected for this program, included high school sophomores, juniors and seniors. The students came from rural South Carolina and adjoining states which, presently, have limited science and computer science facilities. The program focused on high ability minority students, with high potential for science engineering and mathematical careers. The major objective was to increase the pool of well qualified college entering minority students who would elect to go into science, engineering and mathematical careers. The Division of Natural Sciences and Mathematics and engineering at Claflin College received major benefits from this program as it helped them to expand the Departments of Chemistry, Engineering, Mathematics and Computer Science as a result of additional enrollment. It also established an expanded pool of well qualified minority science and mathematics graduates, which were recruited by the federal agencies and private corporations, visiting Claflin College Campus. Department of Energy`s relationship with Claflin College increased the public awareness of energy related job opportunities in the public and private sectors.

Sandhu, S.S.

1994-08-01

200

Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory  

NASA Astrophysics Data System (ADS)

The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 y. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations to be conducted at the Isotope Enrichment Facility (IEF) will be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; ISO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capablities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies.

Scott Aaron, W.; Tracy, Joe G.; Collins, Emory D.

1997-02-01

201

Laser Isotope Enrichment for Medical and Industrial Applications  

SciTech Connect

Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: 1) Pure isotopic targets for irradiation to produce medical radioisotopes. 2) Pure isotopes for semiconductors. 3) Low neutron capture isotopes for various uses in nuclear reactors. 4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ”calutrons” (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation repression. In this scheme a gas, of the selected isotopes for enrichment, is irradiated with a laser at a particular wavelength that would excite only one of the isotopes. The entire gas is subject to low temperatures sufficient to cause condensation on a cold surface. Those molecules in the gas that the laser excited are not as likely to condense as are the unexcited molecules. Hence the gas drawn out of the system will be enriched in the isotope that was excited by the laser. We have evaluated the relative energy required in this process if applied on a commercial scale. We estimate the energy required for laser isotope enrichment is about 20% of that required in centrifuge separations, and 2% of that required by use of "calutrons".

Leonard Bond

2006-07-01

202

Glycoprotein enrichment method using a selective magnetic nano-probe platform (MNP) functionalized with lectins.  

PubMed

Protein post-translational modifications (PTMs) have increasingly become a research field of incredible importance to fully understand the regulation of biological processes in health and disease. Among PTMs, glycosylation is one of the most studied for which contributed the development and improvement of enrichment techniques. Nowadays, glycoprotein enrichment methods are based on lectin affinity, covalent interactions, and hydrophilic interaction liquid chromatography (HILIC). Nonetheless, the nanotechnology era has fetched new methods to enrich glycoproteins from complex samples as human biological fluids. For instance, magnetic nanoparticles (MNPs) are being used as an interesting enrichment approach allowing a better characterization of glycoproteins and glycopeptides.In this chapter, we describe an enrichment method based on MNPs functionalized with lectins (Concavalin A, wheat germ agglutinin, and Maackia amurensis lectin) to enrich specific sets of glycoproteins from biological fluids. Moreover, it is proposed a bioinformatic strategy to deal with data retrieved from mass spectrometry analysis of enriched samples aiming the identification of relevant biological processes modulated by a given stimuli and, ultimately, of new biomarkers for disease screening/management. PMID:25384741

Cova, Marta; Oliveira-Silva, Rui; Ferreira, José Alexandre; Ferreira, Rita; Amado, Francisco; Daniel-da-Silva, Ana Luísa; Vitorino, Rui

2015-01-01

203

MHD performance calculations with oxygen enrichment  

NASA Technical Reports Server (NTRS)

The impact of oxygen enrichment of the combustion air on the generator and overall plant performance was studied for the ECAS-scale MHD/steam plants. A channel optimization technique is described and the results of generator performance calculations using this technique are presented. Performance maps were generated to assess the impact of various generator parameters. Directly and separately preheated plant performance with varying O2 enrichment was calculated. The optimal level of enrichment was a function of plant type and preheat temperature. The sensitivity of overall plant performance to critical channel assumptions and oxygen plant performance characteristics was also examined.

Pian, C. C. P.; Staiger, P. J.; Seikel, G. R.

1979-01-01

204

Unattended Monitoring of HEU Production in Gaseous Centrifuge Enrichment Plants using Automated Aerosol Collection and Laser-based Enrichment Assay  

SciTech Connect

Nuclear power is enjoying rapid growth as government energy policies and public demand shift toward low carbon energy production. Pivotal to the global nuclear power renaissance is the development and deployment of robust safeguards instrumentation that allows the limited resources of the IAEA to keep pace with the expansion of the nuclear fuel cycle. Undeclared production of highly enriched uranium (HEU) remains a primary proliferation concern for modern gaseous centrifuge enrichment plants (GCEPs), due to their massive separative work unit (SWU) processing power and comparably short cascade equilibrium timescale. The Pacific Northwest National Laboratory is developing an unattended safeguards instrument, combining continuous aerosol particulate collection with uranium isotope assay, to provide timely detection of HEU production within a GCEP. This approach is based on laser vaporization of aerosol particulates, followed by laser spectroscopy to characterize the uranium enrichment level. Our prior investigation demonstrated single-shot detection sensitivity approaching the femtogram range and relative isotope ratio uncertainty better than 10% using gadolinium as a surrogate for uranium. In this paper we present measurement results on standard samples containing traces of depleted, natural, and low enriched uranium, as well as measurements on aerodynamic size uranium particles mixed in background materials (e.g., dust, minerals, soils). Improvements and optimizations in the detection electronics, signal timing, calibration, and laser alignment have lead to significant improvements in detection sensitivity and enrichment accuracy, contributing to an overall reduction in the false alarm probability. The sample substrate media was also found to play a significant role in facilitating laser-induced vaporization and the production of energetic plasma conditions, resulting in ablation optimization and further improvements in the isotope abundance sensitivity.

Anheier, Norman C.; Bushaw, Bruce A.

2010-08-11

205

Ultra low-level tritium measurement using electrolytic enrichment and LSC.  

PubMed

We describe an advanced methodology for low-level tritium measurement in regard to calibration, electrolytic tritium enrichment, liquid scintillation counting (LSC) measurement, and prevention of sample contamination. Details are given on enrichment parameters and electrode processes for optimisation of enrichment reproducibility and on optimisation of LSC stability. Intercomparison results demonstrate high accuracy of the tritium measurement system. The use of accurate tritium data for groundwater dating in the southern hemisphere is demonstrated with data from several groundwater systems of New Zealand. PMID:20183224

Morgenstern, Uwe; Taylor, Claude B

2009-06-01

206

Nutrient enrichment, biodiversity loss, and consequent declines in ecosystem productivity  

E-print Network

Nutrient enrichment, biodiversity loss, and consequent declines in ecosystem productivity Forest of chronic nutrient enrichment on ecosystem productivity, and for indirect effects of enrichment on productivity mediated by re- sultant species losses. We found that ecosystem productivity decreased through

Minnesota, University of

207

Development of Enriched Borated Aluminum Alloy for Basket Material of Cask for Spent Nuclear Fuel  

Microsoft Academic Search

New enriched borated aluminum alloys manufactured by melting process are developed, which resulted in supplying structural basket materials for spent nuclear fuel packagings. In this process, the borated aluminum alloys were melted in a vacuum induction furnace at elevated temperature than that of ordinary aluminum melting processes. Boron dissolves into the matrix at the temperature of 1273 K or more,

Katsura Kajihara; Yasuhiro Aruga; Jun Shimojo; Hiroaki Taniuchi; Tsutomu Takeda; Masatosi Sasaki

2002-01-01

208

N2O emissions from a nitrogen-enriched river  

USGS Publications Warehouse

Nitrous oxide (N2O) emissions from the South Platte River in Colorado were measured using closed chambers in the fall, winter, and summer of 1994- 1995. The South Platte River was enriched in inorganic N (9-800 ??M) derived from municipal wastewater effluent and groundwater return flows from irrigated agricultural fields. River water was as much as 2500% supersaturated with N2O, and median N2O emission rates from the river surface ranged from less than 90 to 32 600 ??g-N m-2 d-1. Seventy-nine percent of the variance in N2O emission rates was explained by concentrations of total inorganic N in river water and by water temperature. The estimated total annual N2O emissions from the South Platte River were 2 x 1013-6 x 1013 ??g-N yr-1. This amount of annual N2O emissions was similar to the estimated annual N2O emissions from all primary municipal wastewater treatment processes in the United States (1). Results from this study indicate that N-enriched rivers could be important anthropogenic sources of N2O to the atmosphere. However, N2O emission measurements from other N-enriched rivers are needed to better quantify this source.Nitrous oxide (N2O) emissions from the South Platte River in Colorado were measured using closed chambers in the fall, winter, and summer of 1994-1995. The South Platte River was enriched in inorganic N (9-800 ??M) derived from municipal wastewater effluent and groundwater return flows from irrigated agricultural fields. River water was as much as 2500% supersaturated with N2O, and median N2O emission rates from the river surface ranged from less than 90 to 32 600 ??g-N m-2 d-1. Seventy-nine percent of the variance in N2O emission rates was explained by concentrations of total inorganic N in river water and by water temperature. The estimated total annual N2O emissions from the South Platte River were 2??1013-6??1013 ??g-N yr-1. This amount of annual N2O emissions was similar to the estimated annual N2O emissions from all primary municipal wastewater treatment processes in the United States. Results from this study indicate that N-enriched rivers could be important anthropogenic sources of N2O to the atmosphere. However, N2O emission measurements from other N-enriched rivers are needed to better quantify this source.

McMahon, P.B.; Dennehy, K.F.

1999-01-01

209

Root growth and development in response to CO2 enrichment  

NASA Technical Reports Server (NTRS)

A non-destructive technique (minirhizotron observation tubes) was used to assess the effects of CO2 enrichment on root growth and development in experimental plots in a scrub oak-palmetto community at the Kennedy Space Center. Potential effects of CO2 enrichment on plants have a global significance in light of concerns over increasing CO2 concentrations in the Earth's atmosphere. The study at Kennedy Space Center focused on aboveground physiological responses (photosynthetic efficiency and water use efficiency), effects on process rates (litter decomposition and nutrient turnover), and belowground responses of the plants. Belowground dynamics are an exceptionally important component of total plant response but are frequently ignored due to methodological difficulties. Most methods used to examine root growth and development are destructive and, therefore, severely compromise results. Minirhizotrons allow nondestructive observation and quantification of the same soil volume and roots through time. Root length density and root phenology were evaluated for CO2 effects with this nondestructive technique.

Day, Frank P., Jr.

1994-01-01

210

Chem# - Semantically Enriched Linked Open Chemical Data  

E-print Network

and difficult to discover. The solution: Semantically Enriched Linked Open Chemical Data: browsable, searchable, discoverable and interpretable by humans and machines alike, using standardized extensible data formats (Chemical Markup Language) and technologies...

Adams, Sam; Murray-Rust, Peter; Brooks, Brian; Downing, Jim; Day, Nick

2011-07-05

211

Stable Isotope Enrichment Capabilities at ORNL  

SciTech Connect

The Oak Ridge National Laboratory (ORNL) and the US Department of Energy Nuclear Physics Program have built a high-resolution Electromagnetic Isotope Separator (EMIS) as a prototype for reestablishing a US based enrichment capability for stable isotopes. ORNL has over 60 years of experience providing enriched stable isotopes and related technical services to the international accelerator target community, as well as medical, research, industrial, national security, and other communities. ORNL is investigating the combined use of electromagnetic and gas centrifuge isotope separation technologies to provide research quantities (milligram to several kilograms) of enriched stable isotopes. In preparation for implementing a larger scale production facility, a 10 mA high-resolution EMIS prototype has been built and tested. Initial testing of the device has simultaneously collected greater than 98% enriched samples of all the molybdenum isotopes from natural abundance feedstock.

Egle, Brian [ORNL; Aaron, W Scott [ORNL; Hart, Kevin J [ORNL

2013-01-01

212

Unpalatable prey resolves the paradox of enrichment  

PubMed Central

Enrichment is an increasingly serious trend in natural ecosystems. A theoretical model of a predator–prey system with a natural assumption of satiation in predation predicts that enrichment causes the populations to fluctuate to stochastic extinction. However, this 'paradox of enrichment' does not always occur in experimental and natural communities. Here we present a theoretical model that describes a novel mechanism for resolving the paradox in the case of a predator with optimal selective feeding. Specifically, a less profitable but edible (thus `unpalatable') prey species sharply reduces the amplitude of population oscillations and firmly prevents the minimum abundances of species from falling below certain values. The presence of such an unpalatable prey thus guarantees the robustness of the system against enrichment.

Genkai-Kato, M.; Yamamura, N.

1999-01-01

213

Enriching text with images and colored light  

NASA Astrophysics Data System (ADS)

We present an unsupervised method to enrich textual applications with relevant images and colors. The images are collected by querying large image repositories and subsequently the colors are computed using image processing. A prototype system based on this method is presented where the method is applied to song lyrics. In combination with a lyrics synchronization algorithm the system produces a rich multimedia experience. In order to identify terms within the text that may be associated with images and colors, we select noun phrases using a part of speech tagger. Large image repositories are queried with these terms. Per term representative colors are extracted using the collected images. Hereto, we either use a histogram-based or a mean shift-based algorithm. The representative color extraction uses the non-uniform distribution of the colors found in the large repositories. The images that are ranked best by the search engine are displayed on a screen, while the extracted representative colors are rendered on controllable lighting devices in the living room. We evaluate our method by comparing the computed colors to standard color representations of a set of English color terms. A second evaluation focuses on the distance in color between a queried term in English and its translation in a foreign language. Based on results from three sets of terms, a measure of suitability of a term for color extraction based on KL Divergence is proposed. Finally, we compare the performance of the algorithm using either the automatically indexed repository of Google Images and the manually annotated Flickr.com. Based on the results of these experiments, we conclude that using the presented method we can compute the relevant color for a term using a large image repository and image processing.

Sekulovski, Dragan; Geleijnse, Gijs; Kater, Bram; Korst, Jan; Pauws, Steffen; Clout, Ramon

2008-01-01

214

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2013 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2330 Enriched culture medium. (a) Identification. An enriched...

2013-04-01

215

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2014 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2330 Enriched culture medium. (a) Identification. An enriched...

2014-04-01

216

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2011 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2330 Enriched culture medium. (a) Identification. An enriched...

2011-04-01

217

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2012 CFR

...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2330 Enriched culture medium. (a) Identification. An enriched...

2012-04-01

218

Psychological Enrichment for Animals in Captivity  

Microsoft Academic Search

Animal care in biomedical facilities has undergone a dramatic transformation in the area of psychological well-being and enrichment\\u000a over the past two decades. Today, attending to the behavioral needs of research animals is considered an integral part of\\u000a animal care. Enrichment is defined as environmental stimuli provided to research animals in an effort to improve well-being\\u000a by increasing species-specific and

Coleman Kristine

219

Preparation of a resveratrol-enriched grape juice based on ultraviolet C-treated berries  

Microsoft Academic Search

Grapes are rich in bioactive phenolics. However, most of them remain in the by-product after juice processing, and only a minor part pass to the juice. Our aim was to obtain a resveratrol-enriched white grape juice based on UVC-treated berries in combination with different conditions during juice production. Postharvest UVC treatment of berries enabled the further selective stilbenes enrichment of

R. González-Barrio; M. L. Vidal-Guevara; F. A. Tomás-Barberán; J. C. Espín

2009-01-01

220

Second-stage enrichment in the laser separation of carbon isotopes  

Microsoft Academic Search

There is a general agreement that efficient infrafed laser induced separation of carbon isotopes requires a two-stage process. An efficient first stage 1%?50%13C enrichment was shown by Gauthier et al. [1] to be feasible and competitive with conventional technology. In this work, second-stage CO2 laser enrichment of equimolar mixtures of12CHClF2 and13CHClF2 has been demonstrated yielding tetrafluoroethylene containing 95% or 99%13C.

M. Gauthier; A. Outhouse; Y. Ishikawa; K. O. Kutschke; P. A. Hackett

1984-01-01

221

Using a Technology-Enriched Environment to Improve Higher-Order Thinking Skills  

Microsoft Academic Search

This study examined the effect of a technology-enriched classroom on student development of higher-order thinking skills and student attitudes toward computers. A sample of 80 sixth- grade and ad fifth-grade students was tested using the Ross Test of Higher Cognitive Processes and surveyed using the Computer Attitude Questionnaire. The creation of a technology- enriched classroom environment appears to have had

Michael H. Hopson; Richard L. Simms; Gerald A. Knezek

222

Use of natural antioxidants from lyophilized water extracts of Borago officinalis in dry fermented sausages enriched in ?-3 PUFA  

Microsoft Academic Search

An evaluation of the capacity of a lyophilized water extract of borage leaves to delay the lipid oxidation process in dry fermented sausages enriched with ?-3 PUFAs has been performed. Lyophilized extract (340ppm) showed an antioxidant capacity equivalent to 200ppm of a butylhydroxyanisol (BHA) and butylhydroxytoluene (BHT) mixture. Two batches of dry fermented sausages enriched in ?-3 PUFA were developed.

Mikel García-Iñiguez de Ciriano; Cecilia García-Herreros; Eduardo Larequi; Idoia Valencia; Diana Ansorena; Iciar Astiasarán

2009-01-01

223

77 FR 823 - Guidance for Fuel Cycle Facility Change Processes  

Federal Register 2010, 2011, 2012, 2013, 2014

...processing, fabrication of uranium fuel or fuel assemblies, uranium enrichment, enriched uranium hexafluoride conversion, plutonium processing, or fabrication of mixed-oxide fuel or fuel assemblies. Such fuel cycle facility licensees must establish...

2012-01-06

224

Conversion and Blending Facility highly enriched uranium to low enriched uranium as uranyl nitrate hexahydrate. Revision 1  

SciTech Connect

This Conversion and Blending Facility (CBF) will have two missions: (1) convert HEU materials to pure HEU uranyl nitrate (UNH) and (2) blend pure HEU UNH with depleted and natural UNH to produce HEU UNH crystals. The primary emphasis of this blending operation will be to destroy the weapons capability of large, surplus stockpiles of HEU. The blended LEU product can only be made weapons capable again by the uranium enrichment process. To the extent practical, the chemical and isotopic concentrations of blended LEU product will be held within the specifications required for LWR fuel. Such blended LEU product will be offered to the United States Enrichment Corporation (USEC) to be sold as feed material to the commercial nuclear industry. Otherwise, blended LEU Will be produced as a waste suitable for storage or disposal.

NONE

1995-07-05

225

The proteome of cholesteryl-ester-enriched versus triacylglycerol-enriched lipid droplets.  

PubMed

Within cells, lipids are stored in the form of lipid droplets (LDs), consisting of a neutral lipid core, surrounded by a phospholipid monolayer and an outer layer of protein. LDs typically accumulate either triacylglycerol (TAG) and diacylglycerol or cholesteryl ester (CE), depending on the type of tissue. Recently, there has been an increased interest in the proteins that surround LDs. LD proteins have been found to be quite diverse, from structural proteins to metabolic enzymes, proteins involved in vesicular transport, and proteins that may play a role in LD formation. Previous proteomics analyses have focused on TAG-enriched LDs, whereas CE-enriched LDs have been largely ignored. Our study has compared the LD proteins from CE-enriched LDs to TAG-enriched LDs in steroidogenic cells. In primary rat granulosa cells loaded with either HDL to produce CE-enriched LDs or fatty acids to produce TAG-enriched LDs, 61 proteins were found to be elevated in CE-enriched LDs and 40 proteins elevated in TAG-enriched LDs with 278 proteins in similar amounts. Protein expression was further validated by selected reaction monitoring (SRM) mass spectrometry (MS). SRM verified expression of 25 of 27 peptides that were previously detected by tandem mass tagging MS. Several proteins were confirmed to be elevated in CE-enriched LDs by SRM including the intermediate filament vimentin. This study is the first to compare the proteins found on CE-enriched LDs with TAG-enriched LDs and constitutes the first step in creating a better understanding of the proteins found on CE-enriched LDs in steroidogenic cells. PMID:25111084

Khor, Victor K; Ahrends, Robert; Lin, Ye; Shen, Wen-Jun; Adams, Christopher M; Roseman, Ann Nomoto; Cortez, Yuan; Teruel, Mary N; Azhar, Salman; Kraemer, Fredric B

2014-01-01

226

The Proteome of Cholesteryl-Ester-Enriched Versus Triacylglycerol-Enriched Lipid Droplets  

PubMed Central

Within cells, lipids are stored in the form of lipid droplets (LDs), consisting of a neutral lipid core, surrounded by a phospholipid monolayer and an outer layer of protein. LDs typically accumulate either triacylglycerol (TAG) and diacylglycerol or cholesteryl ester (CE), depending on the type of tissue. Recently, there has been an increased interest in the proteins that surround LDs. LD proteins have been found to be quite diverse, from structural proteins to metabolic enzymes, proteins involved in vesicular transport, and proteins that may play a role in LD formation. Previous proteomics analyses have focused on TAG-enriched LDs, whereas CE-enriched LDs have been largely ignored. Our study has compared the LD proteins from CE-enriched LDs to TAG-enriched LDs in steroidogenic cells. In primary rat granulosa cells loaded with either HDL to produce CE-enriched LDs or fatty acids to produce TAG-enriched LDs, 61 proteins were found to be elevated in CE-enriched LDs and 40 proteins elevated in TAG-enriched LDs with 278 proteins in similar amounts. Protein expression was further validated by selected reaction monitoring (SRM) mass spectrometry (MS). SRM verified expression of 25 of 27 peptides that were previously detected by tandem mass tagging MS. Several proteins were confirmed to be elevated in CE-enriched LDs by SRM including the intermediate filament vimentin. This study is the first to compare the proteins found on CE-enriched LDs with TAG-enriched LDs and constitutes the first step in creating a better understanding of the proteins found on CE-enriched LDs in steroidogenic cells. PMID:25111084

Khor, Victor K.; Ahrends, Robert; Lin, Ye; Shen, Wen-Jun; Adams, Christopher M.; Roseman, Ann Nomoto; Cortez, Yuan; Teruel, Mary N.; Azhar, Salman; Kraemer, Fredric B.

2014-01-01

227

IPAD: the Integrated Pathway Analysis Database for Systematic Enrichment Analysis  

PubMed Central

Background Next-Generation Sequencing (NGS) technologies and Genome-Wide Association Studies (GWAS) generate millions of reads and hundreds of datasets, and there is an urgent need for a better way to accurately interpret and distill such large amounts of data. Extensive pathway and network analysis allow for the discovery of highly significant pathways from a set of disease vs. healthy samples in the NGS and GWAS. Knowledge of activation of these processes will lead to elucidation of the complex biological pathways affected by drug treatment, to patient stratification studies of new and existing drug treatments, and to understanding the underlying anti-cancer drug effects. There are approximately 141 biological human pathway resources as of Jan 2012 according to the Pathguide database. However, most currently available resources do not contain disease, drug or organ specificity information such as disease-pathway, drug-pathway, and organ-pathway associations. Systematically integrating pathway, disease, drug and organ specificity together becomes increasingly crucial for understanding the interrelationships between signaling, metabolic and regulatory pathway, drug action, disease susceptibility, and organ specificity from high-throughput omics data (genomics, transcriptomics, proteomics and metabolomics). Results We designed the Integrated Pathway Analysis Database for Systematic Enrichment Analysis (IPAD, http://bioinfo.hsc.unt.edu/ipad), defining inter-association between pathway, disease, drug and organ specificity, based on six criteria: 1) comprehensive pathway coverage; 2) gene/protein to pathway/disease/drug/organ association; 3) inter-association between pathway, disease, drug, and organ; 4) multiple and quantitative measurement of enrichment and inter-association; 5) assessment of enrichment and inter-association analysis with the context of the existing biological knowledge and a "gold standard" constructed from reputable and reliable sources; and 6) cross-linking of multiple available data sources. IPAD is a comprehensive database covering about 22,498 genes, 25,469 proteins, 1956 pathways, 6704 diseases, 5615 drugs, and 52 organs integrated from databases including the BioCarta, KEGG, NCI-Nature curated, Reactome, CTD, PharmGKB, DrugBank, PharmGKB, and HOMER. The database has a web-based user interface that allows users to perform enrichment analysis from genes/proteins/molecules and inter-association analysis from a pathway, disease, drug, and organ. Moreover, the quality of the database was validated with the context of the existing biological knowledge and a "gold standard" constructed from reputable and reliable sources. Two case studies were also presented to demonstrate: 1) self-validation of enrichment analysis and inter-association analysis on brain-specific markers, and 2) identification of previously undiscovered components by the enrichment analysis from a prostate cancer study. Conclusions IPAD is a new resource for analyzing, identifying, and validating pathway, disease, drug, organ specificity and their inter-associations. The statistical method we developed for enrichment and similarity measurement and the two criteria we described for setting the threshold parameters can be extended to other enrichment applications. Enriched pathways, diseases, drugs, organs and their inter-associations can be searched, displayed, and downloaded from our online user interface. The current IPAD database can help users address a wide range of biological pathway related, disease susceptibility related, drug target related and organ specificity related questions in human disease studies. PMID:23046449

2012-01-01

228

Enrichment Determination of Uranium in Shielded Configurations  

SciTech Connect

The determination of the enrichment of uranium is required in many safeguards and security applications. Typical methods of determining the enrichment rely on detecting the 186 keV gamma ray emitted by {sup 235}U. In some applications, the uranium is surrounded by external shields, and removal of the shields is undesirable. In these situations, methods relying on the detection of the 186 keV gamma fail because the gamma ray is shielded easily. Oak Ridge National Laboratory (ORNL) has previously measured the enrichment of shielded uranium metal using active neutron interrogation. The method consists of measuring the time distribution of fast neutrons from induced fissions with large plastic scintillator detectors. To determine the enrichment, the measurements are compared to a calibration surface that is created from Monte Carlo simulations where the enrichment in the models is varied. In previous measurements, the geometry was always known. ORNL is extending this method to situations where the geometry and materials present are not known in advance. In the new method, the interrogating neutrons are both time and directionally tagged, and an array of small plastic scintillators measures the uncollided interrogating neutrons. Therefore, the attenuation through the item along many different paths is known. By applying image reconstruction techniques, an image of the item is created which shows the position-dependent attenuation. The image permits estimating the geometry and materials present, and these estimates are used as input for the Monte Carlo simulations. As before, simulations predict the time distribution of induced fission neutrons for different enrichments. Matching the measured time distribution to the closest prediction from the simulations provides an estimate of the enrichment. This presentation discusses the method and provides results from recent simulations that show the importance of knowing the geometry and materials from the imaging system.

Crye, Jason Michael [ORNL] [ORNL; Hall, Howard L [ORNL] [ORNL; McConchie, Seth M [ORNL] [ORNL; Mihalczo, John T [ORNL] [ORNL; Pena, Kirsten E [ORNL] [ORNL

2011-01-01

229

Simultaneous enrichment of denitrifying methanotrophs and anammox bacteria.  

PubMed

Interaction between denitrifying anaerobic methane oxidation (DAMO) and anaerobic ammonium oxidation (anammox) processes may play an important role in global carbon and nitrogen cycles. In this study, a coculture of denitrifying methanotrophs (DAMO archaea and DAMO bacteria) and anammox bacteria, initially sourced from the environment, was enriched with a supply of methane, nitrate, and ammonium. After a 4.5-month enrichment, simultaneous oxidation of methane and ammonium and reduction of nitrate were observed. The highest rate of nitrate reduction in the suspended DAMO culture was 4.84 mmol/L/day, and simultaneously, the highest ammonium removal rate was 4.07 mmol/L/day. Fluorescence in situ hybridization and analysis of 16S rRNA gene clone libraries revealed the coexistence of DAMO archaea, DAMO bacteria, and anammox bacteria. The development of anammox bacteria might reduce the enrichment time of DAMO microorganisms and promote the activity of DAMO archaea. The activity of the reactor fluctuated during the long-term operation, which might be caused by the formation of microbial clusters whereby DAMO archaea grew in aggregates that were surrounded by anammox and DAMO bacteria. This study is the first to demonstrate that it is feasible to establish a coculture of DAMO archaea, DAMO bacteria, and anammox bacteria from environmental inocula. PMID:25056292

Ding, Zhao-Wei; Ding, Jing; Fu, Liang; Zhang, Fang; Zeng, Raymond J

2014-12-01

230

Community-aware user profile enrichment in folksonomy.  

PubMed

In the era of big data, collaborative tagging (a.k.a. folksonomy) systems have proliferated as a consequence of the growth of Web 2.0 communities. Constructing user profiles from folksonomy systems is useful for many applications such as personalized search and recommender systems. The identification of latent user communities is one way to better understand and meet user needs. The behavior of users is highly influenced by the behavior of their neighbors or community members, and this can be utilized in constructing user profiles. However, conventional user profiling techniques often encounter data sparsity problems as data from a single user is insufficient to build a powerful profile. Hence, in this paper we propose a method of enriching user profiles based on latent user communities in folksonomy data. Specifically, the proposed approach contains four sub-processes: (i) tag-based user profiles are extracted from a folksonomy tripartite graph; (ii) a multi-faceted folksonomy graph is constructed by integrating tag and image affinity subgraphs with the folksonomy tripartite graph; (iii) random walk distance is used to unify various relationships and measure user similarities; (iv) a novel prototype-based clustering method based on user similarities is used to identify user communities, which are further used to enrich the extracted user profiles. To evaluate the proposed method, we conducted experiments using a public dataset, the results of which show that our approach outperforms previous ones in user profile enrichment. PMID:24907893

Xie, Haoran; Li, Qing; Mao, Xudong; Li, Xiaodong; Cai, Yi; Rao, Yanghui

2014-10-01

231

Lower Metal Enrichment of Virialized Gas in Minihalos  

E-print Network

We differentiate between the metal enrichment of the gas in virialized minihalos and that of the intergalactic medium at high redshift, pertinent to cosmological reionization, with the initial expectation that gas in the high density regions within formed dark matter halos may be more robust thus resistant to mixing with lower density intergalactic medium. Using detailed hydrodynamic simulations of gas clouds in minihalos subject to destructive processes associated with the encompassing intergalactic shocks carrying metal-enriched gas, we find, as an example, that, for realistic shocks of velocities of 10-100km/s, more than (90%,65%) of the high density gas with rho>500 rhob inside a minihalo virialized at z=10 of mass (10^7,10^6)Msun remains at a metallicity lower than 3% of that of the intergalactic medium by redshift z=6. It may be expected that the high density gas in minihalos becomes fuel for subsequent star formation, when they are incorporated into larger halos where efficient atomic cooling can induce gas condensation hence star formation. Since minihalos virialize at high redshift when the universe is not expected to have been significantly reionized, the implication is that gas in virialized minihalos may provide an abundant reservoir of primordial gas to possibly allow for the formation of Population-III metal-free stars to extend to much lower redshift than otherwise expected based on the enrichment of intergalactic medium.

Renyue Cen; Mario A. Riquelme

2007-04-26

232

REDUCTION OF NOx EMISSION FROM COAL COMBUSTION THROUGH OXYGEN ENRICHMENT  

SciTech Connect

BOC Process Gas Solutions and Western Research Institute (WRI) conducted a pilot-scale test program to evaluate the impact of oxygen enrichment on the emissions characteristics of pulverized coal. The combustion test facility (CTF) at WRI was used to assess the viability of the technique and determine the quantities of oxygen required for NOx reduction from coal fired boiler. In addition to the experimental work, a series of Computational Fluid Dynamics (CFD) simulations were made of the CTF under comparable conditions. A series of oxygen enrichment test was performed using the CTF. In these tests, oxygen was injected into one of the following streams: (1) the primary air (PA), (2) the secondary air (SA), and (3) the combined primary and secondary air. Emission data were collected from all tests, and compared with the corresponding data from the baseline cases. A key test parameter was the burner stoichiometry ratio. A series of CFD simulation models were devised to mimic the initial experiments in which secondary air was enriched with oxygen. The results from these models were compared against the experimental data. Experimental evidence indicated that oxygen enrichment does appear to be able to reduce NOx levels from coal combustion, especially when operated at low over fire air (OFA) levels. The reductions observed however are significantly smaller than that reported by others (7-8% vs. 25-50%), questioning the economic viability of the technique. This technique may find favor with fuels that are difficult to burn or stabilize at high OFA and produce excessive LOI. While CFD simulation appears to predict NO amounts in the correct order of magnitude and the correct trend with staging, it is sensitive to thermal conditions and an accurate thermal prediction is essential. Furthermore, without development, Fluent's fuel-NO model cannot account for a solution sensitive fuel-N distribution between volatiles and char and thus cannot predict the trends seen in the experiment.

Western Research Institute

2006-07-01

233

Osteogenic ability of bone marrow stem cells intraoperatively enriched by a novel matrix  

PubMed Central

Poly-L-lysine (PLL) is commonly used as an adhibiting agent due to its good viscosity, and demineralized bone matrix (DBM) is a common enriched matrix for selective cell retention technology. Therefore, the aim of this study was to use PLL to coat the surface and interspaces of DBM to form a novel type of enriched matrix [DBM coated with PLL (PLL-DBM)], in order to effectively improve the enrichment effects of bone marrow stem cells and enhance their osteogenic ability. Electron microscope scanning and the infrared spectrum were used to observe the structure of PLL-DBM and the optimal conditions for the combination of PLL and DBM. Enriching effects on bone marrow nucleated cells (NCs) and platelets (PLTs) were detected with an automated hematology analyzer. The osteogenesis of the following four groups was assessed with a grafting bone model in a goat spinal transverse process: IA, tissue engineered bone (TEB) fabricated following enrichment of bone marrow with PLL-DBM; IB, autogenous iliac bone; IIC, TEB fabricated following enrichment of bone marrow with DBM; IID, blank DBM. The goats were sacrificed in one batch at week 16 after the surgery and the fusion specimens were examined using X-ray and three-dimensional computed tomography (CT). In addition, the CT value was determined and the histology and biomechanics were analyzed in order to evaluate the osteogenic ability. The results showed that PLL and DBM combined well and that PLL-DBM exhibited a natural mesh pore structure. The fold enrichment of NCs and PLTs with PLL-DBM was significantly higher than that with DBM. The fusion effects of the IA and IB groups were similar and significantly enhanced compared with those of the IIC and IID groups. The results confirmed that PLL-DBM is an ideal enriched matrix for bone marrow stem cells, and TEB rapidly fabricated by PLL-DBM intraoperatively enriched bone marrow stem cells exhibits an improved osteogenic ability. PMID:25452771

YE, QING; CHEN, KAINING; HUANG, WU; HE, YUNSONG; NONG, MINGSHAN; LI, CHUNXIANG; LIANG, TIANSEN

2015-01-01

234

Osteogenic ability of bone marrow stem cells intraoperatively enriched by a novel matrix.  

PubMed

Poly-L-lysine (PLL) is commonly used as an adhibiting agent due to its good viscosity, and demineralized bone matrix (DBM) is a common enriched matrix for selective cell retention technology. Therefore, the aim of this study was to use PLL to coat the surface and interspaces of DBM to form a novel type of enriched matrix [DBM coated with PLL (PLL-DBM)], in order to effectively improve the enrichment effects of bone marrow stem cells and enhance their osteogenic ability. Electron microscope scanning and the infrared spectrum were used to observe the structure of PLL-DBM and the optimal conditions for the combination of PLL and DBM. Enriching effects on bone marrow nucleated cells (NCs) and platelets (PLTs) were detected with an automated hematology analyzer. The osteogenesis of the following four groups was assessed with a grafting bone model in a goat spinal transverse process: IA, tissue engineered bone (TEB) fabricated following enrichment of bone marrow with PLL-DBM; IB, autogenous iliac bone; IIC, TEB fabricated following enrichment of bone marrow with DBM; IID, blank DBM. The goats were sacrificed in one batch at week 16 after the surgery and the fusion specimens were examined using X-ray and three-dimensional computed tomography (CT). In addition, the CT value was determined and the histology and biomechanics were analyzed in order to evaluate the osteogenic ability. The results showed that PLL and DBM combined well and that PLL-DBM exhibited a natural mesh pore structure. The fold enrichment of NCs and PLTs with PLL-DBM was significantly higher than that with DBM. The fusion effects of the IA and IB groups were similar and significantly enhanced compared with those of the IIC and IID groups. The results confirmed that PLL-DBM is an ideal enriched matrix for bone marrow stem cells, and TEB rapidly fabricated by PLL-DBM intraoperatively enriched bone marrow stem cells exhibits an improved osteogenic ability. PMID:25452771

Ye, Qing; Chen, Kaining; Huang, Wu; He, Yunsong; Nong, Mingshan; Li, Chunxiang; Liang, Tiansen

2015-01-01

235

Identification of Inservice Needs among Schoolwide Enrichment Schools.  

ERIC Educational Resources Information Center

Specific needs-based inservice training areas were examined for 72 teachers in 3 schools implementing the Schoolwide Enrichment Model for gifted students, using the "Schoolwide Enrichment Teachers' Ratings of Appraised Inservice Needs" measure. The assessment covers preparing for school change, focusing Type III enrichment, implementing enrichment…

Schlichter, Carol L.; Olenchak, F. Richard

1992-01-01

236

The enriched chromium neutrino source for GALLEX  

SciTech Connect

The preparation and study of an intense source of neutrinos in the form of neutron irradiated materials which are enriched in Cr-50 for use in the GALLEX solar neutrino experiment are discussed. Chromyl fluoride gas is enriched in the Cr-50 isotope by gas centrifugation and subsequently converted to a very stable form of chromium oxide. The results of neutron activation analyses of such chromium samples indicate low levels of any long-lived activities, but show that short-lived activities, in particular Na-24, may be of concern. These results show that irradiating chromium oxide enriched in Cr-50 is preferable to irradiating either natural chromium or argon gas as a means of producing a neutrino source to calibrate the GALLEX detector. These results of the impurity level analysis of the enriched chromyl fluoride gas and its conversion to the oxide are also of interest to work in progress by other members of the Collaboration investigating an alternative conversion of the enriched gas to chromium metal. 35 refs., 12 figs., 5 tabs.

Hartmann, F.X.; Hahn, R.L.

1991-01-18

237

Origin of middle rare earth element enrichment in acid mine drainage-impacted areas.  

PubMed

The commonly observed enrichment of middle rare earth elements (MREE) in water sampled in acid mine drainage (AMD)-impacted areas was found to be the result of preferential release from the widespread mineral pyrite (FeS2). Three different mining-impacted sites in Europe were sampled for water, and various pyrite samples were used in batch experiments with diluted sulphuric acid simulating AMD-impacted water with high sulphate concentration and high acidity. All water samples independent on their origin from groundwater, creek water or lake water as well as on the surrounding rock types showed MREE enrichment. Also the pyrite samples showed MREE enrichment in the respective acidic leachate but not always in their total contents indicating a process-controlled release. It is discussed that most probably complexation to sulphite (SO3 (2-)) or another intermediate S-species during pyrite oxidation is the reason for the MREE enrichment in the normalized REE patterns. PMID:24385183

Grawunder, Anja; Merten, Dirk; Büchel, Georg

2014-06-01

238

Difficulties in using 234u/238u ratios to detect enriched or depleted uranium.  

PubMed

Uranium that is highly enriched in U (HEU) is also often also enriched in U because it too is a lower-mass isotope than U and thus its concentration would be preferentially increased in any mass-sensitive enrichment process. Thus the ratio U/U might be regarded as a surrogate for U/U-the usual measure of enrichment. For this reason it has been suggested that U/U measurements be used to detect contamination by HEU. The purpose of this Note is to point out that, because of alpha-recoil effects, U/U varies widely in natural systems, and for this reason it would not be a dependable indicator of the presence of HEU. The same variations would cause U/U ratios to be doubtful indicators of depleted uranium. PMID:18301103

Fleischer, Robert L

2008-03-01

239

Effect of electromagnetic stirring on the enrichment of primary silicon from Al-Si melt  

NASA Astrophysics Data System (ADS)

The effect of electromagnetic stirring on the enrichment of primary silicon from Al-Si melt during the process of electromagnetic separation was investigated. It is shown that the enrichment of primary silicon in Al-Si melt strongly depends on the melt flowing and viscosity gradient. The efficient enrichment of primary silicon was achieved by implementing a high current intensity, which induced a high intense melt flowing. Also, the remaining primary Si in Al-Si alloy could be precipitated by gradually decreasing the current intensity. Additionally, the inductively coupled plasma mass spectrometry (ICP-MS) results show that Si purification is attributed with the enrichment of primary silicon. In this work, the impurity content in primary silicon is 43.3 ppmw, which is much smaller than 777.6 ppmw in metallurgical silicon. Therefore, a potential low-cost technology would be provided for the Si purification.

Yu, Wenzhou; Ma, Wenhui; Lv, Guoqiang; Xue, Haiyang; Li, Shaoyuan; Dai, Yongnian

2014-11-01

240

Enrich: software for analysis of protein function by enrichment and depletion of variants  

PubMed Central

Summary: Measuring the consequences of mutation in proteins is critical to understanding their function. These measurements are essential in such applications as protein engineering, drug development, protein design and genome sequence analysis. Recently, high-throughput sequencing has been coupled to assays of protein activity, enabling the analysis of large numbers of mutations in parallel. We present Enrich, a tool for analyzing such deep mutational scanning data. Enrich identifies all unique variants (mutants) of a protein in high-throughput sequencing datasets and can correct for sequencing errors using overlapping paired-end reads. Enrich uses the frequency of each variant before and after selection to calculate an enrichment ratio, which is used to estimate fitness. Enrich provides an interactive interface to guide users. It generates user-accessible output for downstream analyses as well as several visualizations of the effects of mutation on function, thereby allowing the user to rapidly quantify and comprehend sequence–function relationships. Availability and Implementation: Enrich is implemented in Python and is available under a FreeBSD license at http://depts.washington.edu/sfields/software/enrich/. Enrich includes detailed documentation as well as a small example dataset. Contact: dfowler@uw.edu; fields@uw.edu Supplementary Information: Supplementary data is available at Bioinformatics online. PMID:22006916

Fowler, Douglas M.; Araya, Carlos L.; Gerard, Wayne; Fields, Stanley

2011-01-01

241

The Learning Enrichment Service: A Triad-Based Secondary School Model for Enrichment Programming.  

ERIC Educational Resources Information Center

Three secondary teachers describe a school-wide support system for meeting the needs of gifted students in and beyond the regular classroom. A management team coordinates enrichment within the school and community while a computerized data bank of enrichment resources is accessible to all learners. (CL)

Smyth, Elizabeth; And Others

1983-01-01

242

A model to predict concentration enrichment of contaminants on soil adhering to plants and skin  

Microsoft Academic Search

Transfer of soil contaminants into the food chain has long been a concern. However, certain aspects of the pathways involved have not been fully investigated. One is the enrichment of contaminant concentrations through physical processes such as size-sorting of soil particles. Fine particles selected from soil by processes such as adhesion onto plants will have much higher contaminant concentrations than

S. C. Sheppard

1995-01-01

243

Rotor dynamic analysis of GCEP (Gas Centrifuge Enrichment Plant) Tails Withdrawal Test Facility AC12 compressor  

Microsoft Academic Search

The reliable operation of the centrifugal compressors utilized in the gaseous diffusion process is of great importance due to the critical function of these machines in product and tails withdrawal, cascade purge and evacuation processes, the purge cascade and product booster applications. The same compressors will be used in equally important applications within the Gas Centrifuge Enrichment Plant (GCEP). In

1982-01-01

244

Uranium enrichment management review: summary of analysis  

SciTech Connect

In May 1980, the Assistant Secretary for Resource Applications within the Department of Energy requested that a group of experienced business executives be assembled to review the operation, financing, and management of the uranium enrichment enterprise as a basis for advising the Secretary of Energy. After extensive investigation, analysis, and discussion, the review group presented its findings and recommendations in a report on December 2, 1980. The following pages contain background material on which that final report was based. This report is arranged in chapters that parallel those of the uranium enrichment management review final report - chapters that contain summaries of the review group's discussion and analyses in six areas: management of operations and construction; long-range planning; marketing of enrichment services; financial management; research and development; and general management. Further information, in-depth analysis, and discussion of suggested alternative management practices are provided in five appendices.

Not Available

1981-01-01

245

Nutrient Enrichment Increases Mortality of Mangroves  

PubMed Central

Nutrient enrichment of the coastal zone places intense pressure on marine communities. Previous studies have shown that growth of intertidal mangrove forests is accelerated with enhanced nutrient availability. However, nutrient enrichment favours growth of shoots relative to roots, thus enhancing growth rates but increasing vulnerability to environmental stresses that adversely affect plant water relations. Two such stresses are high salinity and low humidity, both of which require greater investment in roots to meet the demands for water by the shoots. Here we present data from a global network of sites that documents enhanced mortality of mangroves with experimental nutrient enrichment at sites where high sediment salinity was coincident with low rainfall and low humidity. Thus the benefits of increased mangrove growth in response to coastal eutrophication is offset by the costs of decreased resilience due to mortality during drought, with mortality increasing with soil water salinity along climatic gradients. PMID:19440554

Lovelock, Catherine E.; Ball, Marilyn C.; Martin, Katherine C.; C. Feller, Ilka

2009-01-01

246

Fire extinguishment in oxygen enriched atmospheres  

NASA Technical Reports Server (NTRS)

Current state-of-the-art of fire suppression and extinguishment techniques in oxygen enriched atmosphere is reviewed. Four classes of extinguishment action are considered: cooling, separation of reactants, dilution or removal of fuel, and use of chemically reactive agents. Current practice seems to show preference for very fast acting water spray applications to all interior surfaces of earth-based chambers. In space, reliance has been placed on fire prevention methods through the removal of ignition sources and use of nonflammable materials. Recommendations are made for further work related to fire suppression and extinguishment in oxygen enriched atmospheres, and an extensive bibliography is appended.

Robertson, A. F.; Rappaport, M. W.

1973-01-01

247

Enrichment Rescues Contextual Discrimination Deficit Associated With Immediate Shock  

PubMed Central

Adult animals continue to modify their behavior throughout life, a process that is highly influenced by past experiences. To shape behavior, specific mechanisms of neural plasticity to learn, remember, and recall information are required. One of the most robust examples of adult plasticity in the brain occurs in the dentate gyrus (DG) of the hippocampus, through the process of adult neurogenesis. Adult neurogenesis is strongly upregulated by external factors such as voluntary wheel running (RUN) and environmental enrichment (EE); however, the functional differences between these two factors remain unclear. Although both manipulations result in increased neurogenesis, RUN dramatically increases the proliferation of newborn cells and EE promotes their survival. We hypothesize that the method by which these newborn neurons are induced influences their functional role. Furthermore, we examine how EE-induced neurons may be primed to encode and recognize features of novel environments due to their previous enrichment experience. Here, we gave mice a challenging contextual fear-conditioning (FC) procedure to tease out the behavioral differences between RUN-induced neurogenesis and EE-induced neurogenesis. Despite the robust increases in neurogenesis seen in the RUN mice, we found that only EE mice were able to discriminate between similar contexts in this task, indicating that EE mice might use a different cognitive strategy when processing contextual information. Furthermore, we showed that this improvement was dependent on EE-induced neurogenesis, suggesting a fundamental functional difference between RUN-induced neurogenesis and EE-induced neurogenesis. PMID:25330953

Clemenson, Gregory D.; Lee, Star W.; Deng, Wei; Barrera, Vanessa R.; Iwamoto, Kei S.; Fanselow, Michael S.; Gage, Fred H.

2015-01-01

248

Cost analyses of uranium enrichment by laser isotope separation process  

Microsoft Academic Search

The probability of the selective two-step photoionisation of 235U atoms by laser and ultraviolet radiations is estimated from the rate equations for uranium atoms with two isotopes with three levels. The population of 235U ions is obtained by linearising the rate equations. We have calculated the ion production rates for three cases in which the laser and ultraviolet powers are

Norihiko Ozaki; Kimio Yamada; Manabu Yamamoto; Shunsuke Tomiyama; Kiichi Ueyanagi

1976-01-01

249

Using Text Processing Techniques to Automatically enrich a Domain Ontology  

E-print Network

present the experience carried out within the European project FETISH [8], aimed at developing an interoperability infrastructure for small and medium European enterprises that operate in the tourism sector. A key element of the FETISH architecture is OntoTour, a shared ontology for the tourism domain. Constructing

Velardi, Paola

250

Oxygen Enrichment in the Process and Chemical Industries  

E-print Network

separation plants still employ refinements of the low temperature (cryogenic) 1iquefaction/disti llation cycle. Modern plants can produce upwards of 2,000 T/D gaseous oxygen and nitrogen from a single train for delivery by pipeline to the end user.... The gases may also be shipped as pure cryogenic liquids in special insulated transports to customers remote from the plant. The availability of pure oxygen (typically 99.5%) in large quantities at a reasonable cost provided a stimulus...

Milne, R. T.

1984-01-01

251

Natural Occurrence of U 234 Enriched Uranium  

Microsoft Academic Search

The natural occurrence of uranium enriched in U ' has been noted in both Russia and North America [Thurber, 1962]. The same phenomenon was reported by one of the present authors in the course of a recent study of the natural a radioactivity of English drinking waters [Hill, 1962]. This observation was made on the basis of the relative areas

C. R. Hill; J. O. Crookall

1963-01-01

252

New Directions for the Schoolwide Enrichment Model.  

ERIC Educational Resources Information Center

This article considers how the Schoolwide Enrichment Model, originally developed for gifted and talented students, can be applied as part of a comprehensive plan for total school improvement. Modifications to existing curriculum content and skill development are suggested to help all students realize their full potential. (Author/DB)

Renzulli, Joseph S.

1994-01-01

253

Implementing the Schoolwide Enrichment Model in Brazil  

ERIC Educational Resources Information Center

The Schoolwide Enrichment Model (SEM) has been one of the most widely used models in the education of the gifted in Brazil. It has inspired the political and pedagogical project of the Centers of Activities of High Abilities/Giftedness recently implemented in 27 Brazilian states by the Ministry of Education. In this article, our experience in…

de Souza Fleith, Denise; Soriano de Alencar, Eunice M. L.

2010-01-01

254

Arts Internships An opportunity to enrich the  

E-print Network

Arts Internships continued An opportunity to enrich the student experience Each fall, Mc internships is also vitally important. Indeed, these internship experiences are considered so essential of their academic pursuits and future careers. Internships help students become better global citizens and develop

Volesky, Bohumil

255

Computer Enrichment Handbook [and] Supplement A.  

ERIC Educational Resources Information Center

This handbook contains computer-related, classroom-tested ideas that were contributed by business education teachers and administrators to fuse computer information into computer and noncomputer courses. An alphabetical listing of contributors identifies the category/categories in which their enrichment idea can be found. The contributions are…

White, Bonnie Roe, Ed.; And Others

256

How to Enrich Geometry Using String Designs.  

ERIC Educational Resources Information Center

This book presents activities developed for grades 6-10 in creating string designs on polygons and polyhedra. They are designed for use as enrichment materials, each having step-by-step instructions and are arranged from easiest to most difficult, and marked accordingly. The pages are punched and perforated. Many activities are followed by related…

Pohl, Victoria

257

Optimized construction of microsatellite-enriched libraries  

Technology Transfer Automated Retrieval System (TEKTRAN)

The construction of simple sequence repeat (SSR) libraries is an indispensable tool to search for molecular markers as complete genome sequences are still not available for the majority of species of interest. Numerous protocols are available in the literature for the construction of SSR-enriched l...

258

ParentSource: A Practice in Enrichment  

ERIC Educational Resources Information Center

Community-based parenting education programs have a unique role to play in the promotion of infant mental health. In contrast to classes that seek to accelerate child development, the author describes enrichment programs that promote parent-child bonding and healthy social and emotional development. The ParentSource program was developed on the…

Blackwell, Patricia

2005-01-01

259

Projects To Enrich School Mathematics. Level 3.  

ERIC Educational Resources Information Center

This is a series of research projects that can be used for enrichment of the high school mathematics curriculum. It is suggested that the topics are either not found in the standard curriculum or represent a more indepth study of standard topics. The areas considered are: applications of the microcomputer in mathematics; the fourth dimension and…

Sachs, Leroy, Ed.

260

Prototyping Naturalistic Enrichment Features: A Case Study  

Microsoft Academic Search

While working on the research and design phase of a naturalistic Asian rainforest exhibit for the California Science Center's World of Ecology exhibit, we had the unique opportunity to research and develop innovative habitat components intended to showcase naturalistic behaviors. In many cases, the cost of designing and constructing truly naturalistic enrichment devices may not be worthwhile, particularly when it

Greg Whittaker; Margaret Whittaker; Jon Coe

261

Subject Metadata Enrichment using Statistical Topic Models  

E-print Network

Subject Metadata Enrichment using Statistical Topic Models David Newman Department of Computer Libraries University of Michigan Ann Arbor, MI khage@umich.edu Chaitanya Chemudugunta Padhraic Smyth repositories (i.e. data providers). Because OAIster's collection policy is to harvest all of the OAI

Smyth, Padhraic

262

Creating Enrichment Trips for Your Handicapped Students.  

ERIC Educational Resources Information Center

The paper describes "enrichment trips" in which disadvantaged handicapped students travel to various parts of the country to broaden students' awareness. Students had to earn their way through regular attendance, appropriate school behavior, academic achievement, and active participation in fund raising for the trip. Students and teachers worked…

Barber, Robert M.; Parker, James L. F.

263

Biodiesel Lab Exercise with Hydrogen Enrichment  

NSDL National Science Digital Library

The "Biodiesel Lab Exercise with Hydrogen Enrichment" is part of the 2012 SEET Energy Webinar series of presentations, created as an instructional material project during ATEEC/CSM's Sustainable Energy Education and Training (SEET) Workshop for high school and community college energy technology instructors. This resource is free to download. Users must first create a login with ATEEC's website to access the file.

264

Projects To Enrich School Mathematics. Level 2.  

ERIC Educational Resources Information Center

This is a series of research projects that can be used for enrichment of the middle school mathematics curriculum. It is suggested that the topics are either not found in the standard curriculum or represent a more indepth study of standard topics. The areas considered are: microcomputer programs; divisibility; magic squares; pentominoes; the…

Sachs, Leroy, Ed.

265

AFFINITY ENRICHMENT OF BOVINE LACTOFERRIN IN WHEY  

Microsoft Academic Search

Bovine lactoferrin was enriched in various whey samples by affinity chromatography using immobilized gangliosides. Bovine gangliosides were isolated from fresh buttermilk using a combination of ultrafiltration and organic extraction. Isolated gangliosides were covalently immobilized onto controlled-pore glass beads. The immobilized matrix contained 66 micrograms of gangliosides per gram of beads. After loading the matrix with reconstituted whey protein isolate (WPI)

M. K. Walsh; S. H. Nam

2001-01-01

266

Gas Centrifuge Enrichment Plant Safeguards System Modeling  

SciTech Connect

The U.S. Department of Energy (DOE) is interested in developing tools and methods for potential U.S. use in designing and evaluating safeguards systems used in enrichment facilities. This research focuses on analyzing the effectiveness of the safeguards in protecting against the range of safeguards concerns for enrichment plants, including diversion of attractive material and unauthorized modes of use. We developed an Extend simulation model for a generic medium-sized centrifuge enrichment plant. We modeled the material flow in normal operation, plant operational upset modes, and selected diversion scenarios, for selected safeguards systems. Simulation modeling is used to analyze both authorized and unauthorized use of a plant and the flow of safeguards information. Simulation tracks the movement of materials and isotopes, identifies the signatures of unauthorized use, tracks the flow and compilation of safeguards data, and evaluates the effectiveness of the safeguards system in detecting misuse signatures. The simulation model developed could be of use to the International Atomic Energy Agency IAEA, enabling the IAEA to observe and draw conclusions that uranium enrichment facilities are being used only within authorized limits for peaceful uses of nuclear energy. It will evaluate improved approaches to nonproliferation concerns, facilitating deployment of enhanced and cost-effective safeguards systems for an important part of the nuclear power fuel cycle.

Elayat, H A; O'Connell, W J; Boyer, B D

2006-06-05

267

Fast and Convenient 5-hydroxymethylcytosine Enrichment  

E-print Network

Fast and Convenient 5-hydroxymethylcytosine Enrichment Workflow for Next-Generation Sequencing, or sequencing (if a whole genome is analyzed). The procedure is completed in less than 3 hours. #12;2 For next-generation generation sequencing offers new ways of analyzing 5-hmC at the genomic level. We demonstrate that the Thermo

Cai, Long

268

Method for laser induced isotope enrichment  

DOEpatents

Methods for separating isotopes or chemical species of an element and causing enrichment of a desired isotope or chemical species of an element utilizing laser ablation plasmas to modify or fabricate a material containing such isotopes or chemical species are provided. This invention may be used for a wide variety of materials which contain elements having different isotopes or chemical species.

Pronko, Peter P.; Vanrompay, Paul A.; Zhang, Zhiyu

2004-09-07

269

Thermogenic Effect from Nutritionally Enriched Coffee Consumption  

Microsoft Academic Search

BACKGROUND: The purpose of this study was to examine the effect of nutritionally enriched JavaFit™ (JF) coffee (450 mg of caffeine, 1200 mg of garcinia cambogia, 360 mg of citrus aurantium extract, and 225 mcg of chromium polynicotinate) on resting oxygen uptake (VO2), respiratory exchange ratio (RER), heart rate (HR), and blood pressure (BP) in healthy and physically active individuals.

Jay R. Hoffman; Jie Kang; Nicholas A. Ratamess; Peter F. Jennings; Gerald Mangine; Avery D Faigenbaum

2006-01-01

270

Assessment of liquid disposal originated by uranium enrichment at Aramar Experimental Center São Paulo--Brazil.  

PubMed

This work presents a liquid disposal monitoring originated from uranium enrichment process at Aramar Experimental Center from 1990 to 1998. Assessment of uranium, fluorides, ammoniacal nitrogen, chemical oxygen demand, and pH measurements were made in water samples and compared with results achieved in other countries, as North America and India. The liquid disposal evaluation, generated by uranium enrichment process, showed low levels, considering most parameters established by Federal and State Legislation, aiming environmental pollution control. However, uranium levels were above the limits established by Conselho Nacional do Meio Ambiente, Environment Protection Agency and mainly by the World Health Organization. PMID:21814717

Gerenutti, Marli; Gonçalves, Marcos Moisés; Rissato, Sandra Regina; de Oliveira, José Martins; dos Santos Reigota, Marco Antonio; Galhiane, Mário Sergio

2012-07-01

271

STEM enrichment programs and graduate school matriculation: the role of science identity salience.  

PubMed

Improving the state of science education in the United States has become a national priority. One response to this problem has been the implementation of STEM enrichment programs designed to increase the number of students that enter graduate programs in science. Current research indicates enrichment programs have positive effects for student performance, degree completion, interest in science and graduate enrollment. Moreover, research suggests that beyond improving performance in STEM, and providing access to research experience and faculty mentoring, enrichment programs may also increase the degree to which students identify as scientists. However, researchers investigating the role of science identity on student outcomes have focused primarily on subjective outcomes, leaving a critical question of whether science identity also influences objective outcomes such as whether students attend graduate school. Using identity theory, this study addresses this issue by investigating science identity as a mechanism linking enrichment program participation to matriculation into graduate science programs. Quantitative results from a panel study of 694 students indicate that science identity salience, along with research experience and college GPA, mediate the effect of enrichment program participation on graduate school matriculation. Further, results indicate that although the social psychological process by which science identity salience develops operates independently from student GPA, science identity amplifies the effect of achievement on graduate school matriculation. These results indicate that policies seeking to increase the efficacy of enrichment programs and increase representation in STEM graduate programs should be sensitive to the social and academic aspects of STEM education. PMID:24578606

Merolla, David M; Serpe, Richard T

2013-12-01

272

STEM enrichment programs and graduate school matriculation: the role of science identity salience  

PubMed Central

Improving the state of science education in the United States has become a national priority. One response to this problem has been the implementation of STEM enrichment programs designed to increase the number of students that enter graduate programs in science. Current research indicates enrichment programs have positive effects for student performance, degree completion, interest in science and graduate enrollment. Moreover, research suggests that beyond improving performance in STEM, and providing access to research experience and faculty mentoring, enrichment programs may also increase the degree to which students identify as scientists. However, researchers investigating the role of science identity on student outcomes have focused primarily on subjective outcomes, leaving a critical question of whether science identity also influences objective outcomes such as whether students attend graduate school. Using identity theory, this study addresses this issue by investigating science identity as a mechanism linking enrichment program participation to matriculation into graduate science programs. Quantitative results from a panel study of 694 students indicate that science identity salience, along with research experience and college GPA, mediate the effect of enrichment program participation on graduate school matriculation. Further, results indicate that although the social psychological process by which science identity salience develops operates independently from student GPA, science identity amplifies the effect of achievement on graduate school matriculation. These results indicate that policies seeking to increase the efficacy of enrichment programs and increase representation in STEM graduate programs should be sensitive to the social and academic aspects of STEM education. PMID:24578606

Serpe, Richard T.

2013-01-01

273

Tracking wind-dispersed seeds using (15)N-isotope enrichment.  

PubMed

Seed dispersal influences a wide range of ecological processes. However, measuring dispersal patterns, particularly long-distance dispersal, has been a difficult task. Marking bird-dispersed seeds with stable (15)N isotopes has been shown to be a user-friendly method to trace seed dispersal. In this study, we determined whether (15)N urea solution could be used to enrich seeds of two common wind-dispersed plants, Eupatorium glaucescens (Asteraceae) and Sericocarpus tortifolius (Asteraceae). We further tested if the water type (distilled versus tap) in (15)N urea solutions influences the level and variability of enrichment of plant seeds, and if increasing spraying frequency per se increases enrichment. Because droughts may lower seed set or kill plants, we wanted to investigate if the additional use of an externally applied anti-transpirant affects the intake of externally applied (15)N into seeds. The results demonstrate that (15)N enrichment of seeds can facilitate dispersal experiments with wind-dispersed plants. The use of distilled water in (15)N urea solutions did not increase (15)N enrichment compared to tap water. Further, enrichment was more efficient at lower spray frequencies. Both the use of tap water and low frequencies could lower time, effort and project costs. The results suggest that species can be protected from drought using an anti-transpirant without decreasing the incorporation of (15)N into seeds. PMID:25174806

Forster, C; Herrmann, J D

2014-11-01

274

Optimization of enrichment distributions in nuclear fuel assemblies loaded with uranium and plutonium via a modified linear programming technique  

NASA Astrophysics Data System (ADS)

A methodology to optimize enrichment distributions in Light Water Reactor (LWR) fuel assemblies is developed and tested. The optimization technique employed is the linear programming revised simplex method, and the fuel assembly's performance is evaluated with a neutron transport code that is also utilized in the calculation of sensitivity coefficients. The enrichment distribution optimization procedure begins from a single-value (flat) enrichment distribution until a target, maximum local power peaking factor, is achieved. The optimum rod enrichment distribution, with 1.00 for the maximum local power peaking factor and with each rod having its own enrichment, is calculated at an intermediate stage of the analysis. Later, the best locations and values for a reduced number of rod enrichments is obtained as a function of a target maximum local power peaking factor by applying sensitivity to change techniques. Finally, a shuffling process that assigns individual rod enrichments among the enrichment groups is performed. The relative rod power distribution is then slightly modified and the rod grouping redefined until the optimum configuration is attained. To verify the accuracy of the relative rod power distribution, a full computation with the neutron transport code using the optimum enrichment distribution is carried out. The results are compared and tested for assembly designs loaded with fresh Low Enriched Uranium (LEU) and plutonium Mixed OXide (MOX) fuels. MOX isotopics for both reactor-grade and weapons-grade plutonium were utilized to demonstrate the wide-range of applicability of the optimization technique. The features of the assembly designs used for evaluation purposes included burnable absorbers and internal water regions, and were prepared to resemble the configurations of modern assemblies utilized in commercial Boiling Water Reactors (BWRs) and Pressurized Water Reactors (PWRs). In some cases, a net improvement in the relative rod power distribution or in the number of enrichments is accomplished with this methodology.

Cuevas Vivas, Gabriel Francisco

275

Enriched Pyrite ?34S Signals in Modern Tropical Deltaic Muds  

NASA Astrophysics Data System (ADS)

The biogeochemical cycling of sulfur is one of the primary processes that regulate the Earth's surface redox conditions. In this study, we examine the abundance and sulfur isotopic composition (?34S) of pyrite through a series of cores collected from different water depths from the Gulf of Papua, Papua New Guinea. Physically undisturbed cores from deep water (depths up to 50 m) show relatively smooth ?34Spyr profiles with small scatter between adjacent samples within a core. In these cores, ?34Spyr gets gradually enriched from ~ -32‰ in the upper section to ~ -25‰ in the lower section. On the other hand, the ?34Spyr profiles in cores from shallow water depths (8 - 18 m) present larger scatter (up to 35‰) and unusually enriched ?34Spyr values (up to +36‰) are observed. These disparate results can be understood by combining a Rayleigh distillation model to explain elevated 34S values under closed-system conditions, together with the impact of episodic reworking of sediments, which enhances the stratigraphic variability of sulfide isotopic signals. Such different ?34Spyr patterns (both in their mean values and the degree of variability) between shallow water and deep water depositional environments, if preserved in the geologic record, could result in disparate interpretations. Understanding how modern depositional and diagenetic environments impact sulfur cycling processes gives us new insights when interpreting ancient sulfur isotope records.

Gao, J.; Fike, D. A.; Aller, R. C.

2013-12-01

276

THE FIRST GALAXIES: CHEMICAL ENRICHMENT, MIXING, AND STAR FORMATION  

SciTech Connect

Using three-dimensional cosmological simulations, we study the assembly process of one of the first galaxies, with a total mass of {approx}10{sup 8} M {sub sun}, collapsing at z {approx_equal} 10. Our main goal is to trace the transport of the heavy chemical elements produced and dispersed by a pair-instability supernova exploding in one of the minihalo progenitors. To this extent, we incorporate an efficient algorithm into our smoothed particle hydrodynamics code that approximately models turbulent mixing as a diffusion process. We study this mixing with and without the radiative feedback from Population III (Pop III) stars that subsequently form in neighboring minihalos. Our simulations allow us to constrain the initial conditions for second-generation star formation, within the first galaxy itself, and inside of minihalos that virialize after the supernova explosion. We find that most minihalos remain unscathed by ionizing radiation or the supernova remnant, while some are substantially photoheated and enriched to supercritical levels, likely resulting in the formation of low-mass Pop III or even Population II (Pop II) stars. At the center of the newly formed galaxy, {approx}10{sup 5} M {sub sun} of cold, dense gas uniformly enriched to {approx}10{sup -3} Z {sub sun} is in a state of collapse, suggesting that a cluster of Pop II stars will form. The first galaxies, as may be detected by the James Webb Space Telescope, would therefore already contain stellar populations familiar from lower redshifts.

Greif, Thomas H. [Max-Planck-Institut fuer Astrophysik, Karl-Schwarzschild-Strasse 1, 85740 Garching bei Muenchen (Germany); Glover, Simon C. O.; Klessen, Ralf S. [Zentrum fuer Astronomie der Universitaet Heidelberg, Institut fuer Theoretische Astrophysik, Albert-Ueberle-Strasse 2, 69120 Heidelberg (Germany); Bromm, Volker, E-mail: tgreif@mpa-garching.mpg.d [Department of Astronomy, University of Texas, Austin, TX 78712 (United States)

2010-06-10

277

Axi-symmetrical flow reactor for [sup 196]Hg photochemical enrichment  

DOEpatents

The present invention is directed to an improved photochemical reactor useful for the isotopic enrichment of a predetermined isotope of mercury, especially, [sup 196]Hg. Specifically, two axi-symmetrical flow reactors were constructed according to the teachings of the present invention. These reactors improve the mixing of the reactants during the photochemical enrichment process, affording higher yields of the desired [sup 196]Hg product. Measurements of the variation of yield (Y) and enrichment factor (E) along the flow axis of these reactors indicates very substantial improvement in process uniformity compared to previously used photochemical reactor systems. In one preferred embodiment of the present invention, the photoreactor system was built such that the reactor chamber was removable from the system without disturbing the location of either the photochemical lamp or the filter employed therewith. 10 figures.

Grossman, M.W.

1991-04-30

278

Analysis of the effectiveness of gas centrifuge enrichment plants advanced safeguards  

SciTech Connect

Current safeguards approaches used by the International Atomic Energy Agency (IAEA) at gas centrifuge enrichment plants (GCEPs) need enhancement in order to verify declared low-enriched uranium (LEU) production, detect undeclared LEU production and detect highly enriched uranium (HEU) production with adequate detection probability using non destructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and 235U enrichment of declared UF6 containers used in the process of enrichment at GCEPs. This paper contains an analysis of possible improvements in unattended and attended NDA systems including process monitoring and possible on-site destructive assay (DA) of samples that could reduce the uncertainty of the inspector's measurements. These improvements could reduce the difference between the operator's and inspector's measurements providing more effective and efficient IAEA GCEPs safeguards. We also explore how a few advanced safeguards systems could be assembled for unattended operation. The analysis will focus on how unannounced inspections (UIs), and the concept of information-driven inspections (IDS) can affect probability of detection of the diversion of nuclear materials when coupled to new GCEPs safeguards regimes augmented with unattended systems.

Boyer, Brian David [Los Alamos National Laboratory; Erpenbeck, Heather H [Los Alamos National Laboratory; Miller, Karen A [Los Alamos National Laboratory; Swinjoe, Martyn T [Los Alamos National Laboratory; Ianakiev, Kiril D [Los Alamos National Laboratory; Marlow, Johnna B [Los Alamos National Laboratory

2010-01-01

279

Gas centrifuge enrichment plants inspection frequency and remote monitoring issues for advanced safeguards implementation  

SciTech Connect

Current safeguards approaches used by the IAEA at gas centrifuge enrichment plants (GCEPs) need enhancement in order to verify declared low enriched uranium (LEU) production, detect undeclared LEU production and detect high enriched uranium (BEU) production with adequate probability using non destructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector for operation, during inspections to verify the mass and {sup 235}U enrichment of declared cylinders of uranium hexafluoride that are used in the process of enrichment at GCEPs. This paper contains an analysis of how possible improvements in unattended and attended NDA systems including process monitoring and possible on-site destructive analysis (DA) of samples could reduce the uncertainty of the inspector's measurements providing more effective and efficient IAEA GCEPs safeguards. We have also studied a few advanced safeguards systems that could be assembled for unattended operation and the level of performance needed from these systems to provide more effective safeguards. The analysis also considers how short notice random inspections, unannounced inspections (UIs), and the concept of information-driven inspections can affect probability of detection of the diversion of nuclear material when coupled to new GCEPs safeguards regimes augmented with unattended systems. We also explore the effects of system failures and operator tampering on meeting safeguards goals for quantity and timeliness and the measures needed to recover from such failures and anomalies.

Boyer, Brian David [Los Alamos National Laboratory; Erpenbeck, Heather H [Los Alamos National Laboratory; Miller, Karen A [Los Alamos National Laboratory; Ianakiev, Kiril D [Los Alamos National Laboratory; Reimold, Benjamin A [Los Alamos National Laboratory; Ward, Steven L [Los Alamos National Laboratory; Howell, John [GLASGOW UNIV.

2010-09-13

280

The Economics of Oxygen Enriched Air Production Via Membranes  

E-print Network

Oxygen enriched air combustion is a recognized approach to energy conservation. Conventional methods of producing oxygen enriched air: Pressure Swing Adsorption and Cryogenics, are energy-intensive and expensive. In this paper the economics of using...

Gollan, A.; Kleper, M. H.

1984-01-01

281

Enriched model categories and diagram categories  

E-print Network

We collect in one place a variety of known and folklore results in enriched model category theory and add a few new twists. One twist is a new perspective on equivariant model categories. A central theme is a general procedure for constructing a Quillen adjunction, often a Quillen equivalence, between a given V-model category and a category of diagrams in V, where V is any good enriching category. From this perspective, we rederive the result of Schwede and Shipley that reasonable stable model categories are Quillen equivalent to diagram categories of spectra (alias categories of module spectra). The general theory will be applied to G-spectra in a sequel, and for that we need quite a few technical improvements and modifications of general model categorical results. We collect those here. They are bound to have applications in a variety of other contexts.

Guillou, Bertrand

2011-01-01

282

The self-enrichment of globular clusters  

NASA Astrophysics Data System (ADS)

It is shown that protoglobular clusters of primordial gas can confine the supernovae needed to enrich themselves. The required protocluster cloud masses and structural parameters are the same as those currently observed for the clusters. Two causal scenarios for star formation are examined to calculate the initial enrichment of primordial clouds. In the 'Christmas tree' scheme, the maximum final (Fe/H) is about 0.1. Since the time scale for formation and evolution of massive stars at the center of a cluster is nearly an order of magnitude less than the collapse time of the cluster, every globular cluster may have to survive a suprernova detonation. If this is the case, the minimum mass of a globular cluster is about 10 to the 4.6th solar mass.

Morgan, Siobahn; Lake, George

1989-04-01

283

Mutant Enrichment with 3?-Modified Oligonucleotides  

PubMed Central

Many clinical situations necessitate highly sensitive and reliable molecular assays; however, the achievement of such assays remains a challenge due to the inherent limitations of molecular testing methods. Here, we describe a simple and inexpensive enrichment technique that we call mutant enrichment with 3?-modified oligonucleotides (MEMO). The method is based on the use of a 3?-modified oligonucleotide primer that blocks extension of the normal allele but enables extension of the mutated allele. The performance of the technique was evaluated with respect to its ability to detect common cancer mutations in the EGFR, KRAS, BRAF, TP53, JAK2, and NPM1 genes. We achieved sensitivities of 10?2 to 10?6 using downstream Sanger sequencing, depending on the concentrations and thermodynamics of the primers. MEMO may be applicable to the quantitative real-time PCR platform and other downstream assays. This technique may be practically applicable to various medical situations. PMID:21979247

Lee, Seung-Tae; Kim, Ji-Youn; Kown, Min-Jung; Kim, Sun Wook; Chung, Jae Hoon; Ahn, Myung-Ju; Oh, Young Lyun; Kim, Jong-Won; Ki, Chang-Seok

2011-01-01

284

Clustering of Marine Bacteria in Seawater Enrichments  

Microsoft Academic Search

Seawater enrichments of marine bacteria clustered in 20- to 50-mm-wide bands near air-water interfaces. The cells within the band travelled at up to 212 m ms 2 1and at an average speed of 163 m ms 2 1. Mean cell speeds peaked mid-run at 187 mms 21. At the end of the run, bacteria reversed direction rather than randomly reorienting.

JAMES G. MITCHELL; LYNETTE PEARSON; ANDSIMON DILLON

1996-01-01

285

THE MAGIC WAND: ENRICHING SHARED STORYBOOK READING  

Microsoft Academic Search

This paper introduces the 'Magic Wand', a system that works next to existing physical books and adds an extra dimension (i.e. sound) to shared storybook reading for adults and children by providing a simple and intuitive interaction. The 'Magic Wand': 1) enriches the shared book-reading experience by adding supporting sounds, 2) provides a low-tech and accessible way of identifying sounds

Chris Heger; Andrés Lucero

286

Environmental enrichment decreases responding for visual novelty  

PubMed Central

Previous research has demonstrated that rats reared in an enriched condition (EC) with novel objects and social partners self-administer less amphetamine compared to rats raised in an isolated condition (IC). However, it is unclear if the enrichment-induced decrease in stimulant self-administration generalizes to non-drug rewards such as those provided by novel environmental stimuli. In the current study, EC, IC, and social condition (SC) rats were raised from 21 to 51 days of age before being tested in a two-lever operant conditioning chamber in which responding on one lever (active lever) resulted in illumination of a cue light. In Experiment 1, rats were initially assessed for baseline responding (no contingency) and then the contingent light was introduced. EC rats responded less than IC rats for the contingent light stimulus; however, EC rats also displayed a lower rate of baseline responding. In Experiment 2, rats were trained initially to lever press for a sucrose reward to decrease differences in baseline responding. While sucrose pretraining decreased baseline response differences between groups, EC rats still responded less for the contingent light stimulus than IC or SC rats. These results suggest that environmental enrichment decreases the incentive value of visual novelty. PMID:16987609

Cain, Mary E.; Green, Thomas A.; Bardo, Michael T.

2006-01-01

287

Supply of enriched uranium for research reactors  

SciTech Connect

Since the RERTR-meeting In Newport/USA in 1990 the author delivered a series of papers in connection with the fuel cycle for research reactors dealing with its front-end. In these papers the author underlined the need for unified specifications for enriched uranium metal suitable for the production of fuel elements and made proposals with regard to the re-use of in Europe reprocessed highly enriched uranium. With regard to the fuel cycle of research reactors the research reactor community was since 1989 more concentrating on the problems of its back-end since the USA stopped the acceptance of spent research reactor fuel on December 31, 1988. Now, since it is apparent that these back-end problem have been solved by AEA`s ability to reprocess and the preparedness of the USA to again accept physically spent research reactor fuel the author is focusing with this paper again on the front-end of the fuel cycle on the question whether there is at all a safe supply of low and high enriched uranium for research reactors in the future.

Mueller, H. [NUKEM GmbH, Alzenau (Germany)

1997-08-01

288

Meeting the Enrichment Needs of Middle School Students.  

ERIC Educational Resources Information Center

Through a continuum-of-services approach, the Schoolwide Enrichment Model (SEM) provides numerous enrichment and acceleration alternatives designed to accommodate the academic strengths, interests, and learning styles of all middle-level students. Major components include the total-talent portfolio, curriculum modification, and enrichment…

Renzulli, Joseph S.; Richards, Susannah

2000-01-01

289

21 CFR 137.260 - Enriched corn meals.  

Code of Federal Regulations, 2012 CFR

...2012-04-01 2012-04-01 false Enriched corn meals. 137.260 Section 137.260 Food and...Flours and Related Products § 137.260 Enriched corn meals. (a) Enriched corn meals are the foods, each of which conforms...

2012-04-01

290

21 CFR 137.260 - Enriched corn meals.  

Code of Federal Regulations, 2014 CFR

...2014-04-01 2014-04-01 false Enriched corn meals. 137.260 Section 137.260 Food and...Flours and Related Products § 137.260 Enriched corn meals. (a) Enriched corn meals are the foods, each of which conforms...

2014-04-01

291

21 CFR 137.260 - Enriched corn meals.  

Code of Federal Regulations, 2011 CFR

...2011-04-01 2011-04-01 false Enriched corn meals. 137.260 Section 137.260 Food and...Flours and Related Products § 137.260 Enriched corn meals. (a) Enriched corn meals are the foods, each of which conforms...

2011-04-01

292

21 CFR 137.260 - Enriched corn meals.  

Code of Federal Regulations, 2013 CFR

...2013-04-01 2013-04-01 false Enriched corn meals. 137.260 Section 137.260 Food and...Flours and Related Products § 137.260 Enriched corn meals. (a) Enriched corn meals are the foods, each of which conforms...

2013-04-01

293

21 CFR 137.260 - Enriched corn meals.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 2010-04-01 false Enriched corn meals. 137.260 Section 137.260 Food and...Flours and Related Products § 137.260 Enriched corn meals. (a) Enriched corn meals are the foods, each of which conforms...

2010-04-01

294

Defining the needs for gas centrifuge enrichment plants advanced safeguards  

Microsoft Academic Search

Current safeguards approaches used by the International Atomic Energy Agency (IAEA) at gas centrifuge enrichment plants (GCEPs) need enhancement in order to verify declared low-enriched (LEU) production, detect undeclared LEU production and detect highly enriched uranium (HEU) production with adequate detection probability using nondestructive assay (NDA) techniques. At present inspectors use attended systems, systems needing the presence of an inspector

Brian David Boyer; Heather H Erpenbeck; Karen A Miller; Martyn T Swinhoe; Kiril Ianakiev; Johnna B Marlowe

2010-01-01

295

India's Gas Centrifuge Enrichment Program: Growing Capacity for Military Purposes  

Microsoft Academic Search

This report traces the history of India's centrifuge enrichment program and assesses its current and projected enrichment capacity based on publicly available procurement data and other publicly available information, which were analyzed using specialized software. Our conclusion is that India is currently operating between 2,000 and 3,000 centrifuges at the Rare Materials Project (RMP), India's primary centrifuge enrichment facility approximately

David Albright; Susan Basu

296

75 FR 21680 - GE-Hitachi Global Laser Enrichment LLC;  

Federal Register 2010, 2011, 2012, 2013, 2014

...10-901-03-ML-BD01] GE-Hitachi Global Laser Enrichment LLC; Establishment of Atomic...following proceeding: GE-Hitachi Global Laser Enrichment LLC (GLE Commercial Facility...the application of GE-Hitachi Global Laser Enrichment LLC for a license to...

2010-04-26

297

Soil organic carbon enrichment of dust emissions: magnitude, mechanisms and its implications for  

E-print Network

Soil organic carbon enrichment of dust emissions: magnitude, mechanisms and its implications Range, MSC 3 JER, NMSU, Box 30003, Las Cruces, NM 88003-8003, USA. E-mail: nwebb@nmsu.edu ABSTRACT: Soil to the role of aeolian processes in influencing soil organic carbon (SOC) flux and the release of greenhouse

298

Salmonella Recovery Following Immersion Chilling for Matched Neck Skin and Whole Carcass Enrichment Sampling Methodologies  

Technology Transfer Automated Retrieval System (TEKTRAN)

The prevalence and serogroups of Salmonella recovered following immersion chilling were determined for both neck skin and the matching whole carcass enriched samples. Commercially processed and eviscerated broiler carcasses were immersion chilled in ice and tap water for 40 min. Following immersio...

299

Non-additive effects of litter mixing are suppressed in a nutrient-enriched stream  

E-print Network

Non-additive effects of litter mixing are suppressed in a nutrient-enriched stream Amy D. Rosemond processes are currently lacking. Many studies have shown that mixed species plant litters exhibit non leaf litter species with distinct initial chemistries (carbon:nitrogen; C:N) and breakdown rates

Rosemond, Amy Daum

300

Automatically Grounding Semantically-enriched Conceptual Models to Concrete Web Services  

E-print Network

Automatically Grounding Semantically-enriched Conceptual Models to Concrete Web Services Eran Toch semantic Web services. We envision a world in which a designer defines a "virtual" Web service as part of a business process, while requiring the system to seek actual Web services that match the specifi- cations

Gal, Avigdor

301

Oxalic acid complexes: promising draw solutes for forward osmosis (FO) in protein enrichment.  

PubMed

Highly soluble oxalic acid complexes (OACs) were synthesized through a one-pot reaction. The OACs exhibit excellent performance as draw solutes in FO processes with high water fluxes and negligible reverse solute fluxes. Efficient protein enrichment was achieved. The diluted OACs can be recycled via nanofiltration and are promising as draw solutes. PMID:25697506

Ge, Qingchun; Chung, Tai-Shung

2015-03-01

302

The effects of resource enrichment, dispersal, and predation on local and metacommunity structure  

Microsoft Academic Search

Community structure is the observable outcome of numerous processes. We conducted a laboratory experiment using a microbial model system to disentangle effects of nutrient enrichment, dispersal, and predation on prey species richness and predator abundance at local and metacommunity scales. Prey species included: Chilomonas sp., Colpidium striatum, Colpoda cucullus, Paramecium tetraurelia, P. caudatum, Philodina sp., Spirostomum sp., Tetrahymena thermophila, and

Marc W. Cadotte; Allison M. Fortner; Tadashi Fukami

2006-01-01

303

twzPEA: A Topology and Working Zone Based Pathway Enrichment Analysis Framework  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sensitive detection of involvement and adaptation of key signaling, regulatory, and metabolic pathways holds the key to deciphering molecular mechanisms such as those in the biomass-to-biofuel conversion process in yeast. Typical gene set enrichment analyses often do not use topology information in...

304

Using a Technology-Enriched Environment To Improve Higher-Order Thinking Skills.  

ERIC Educational Resources Information Center

Examined the effects of a technology-enriched classroom on student development of higher-order thinking skills and student attitudes toward computers in grades five and six. Describes use of the Ross Test of Higher Cognitive Processes and the Computer Attitude Questionnaire, compares results with students in traditional classrooms, and suggest…

Hopson, Michael H.; Simms, Richard L.; Knezek, Gerald A.

2002-01-01

305

Ice-Enriched Loess and the Formation of Periglacial Terrain in Mid-Utopia Planitia, Mars  

NASA Astrophysics Data System (ADS)

Landforms suggestive of periglacial processes are commonplace in mid-Utopia Planitia, Mars. They form syngenetically in ground-ice comprised of loess transported by katabatic wind from the NPLDs and enriched by ice through the thaw-freeze cycling of obliquity-driven precipitation.

Soare, R. J.; Conway, S. J.; Pearce, G. D.; Costard, F.

2012-03-01

306

Towards ontology personalization to enrich social conversations on AAC systems  

NASA Astrophysics Data System (ADS)

Communication is one of the essential needs of human beings. Augmentative and Alternative Communication Systems (AAC) seek to help in the generation of oral and written language to people with physical disorders that limit their natural communication. These systems present significant challenges such as: the composition of consistent messages according to syntactic and semantic rules, the improvement of message production times, the application to social contexts and, consequently, the incorporation of user-specific information. This work presents an original ontology personalization approach for an AAC instant messaging system incorporating personalized information to improve the efficacy and efficiency of the message production. This proposal is based on a projection of a general ontology into a more specific one, avoiding storage redundancy and data coupling, representing a big opportunity to enrich communication capabilities of current AAC systems. The evaluation was performed for a study case based on an AAC system for assistance in composing messages. The results show that adding user-specific information allows generation of enriched phrases, so improving the accuracy of the message, facilitating the communication process.

Mancilla V., Daniela; Sastoque H., Sebastian; Iregui G., Marcela

2015-01-01

307

Fissile Flow and Enrichment Monitor for GCEP Advanced Safeguards Application  

SciTech Connect

This paper presents experimental data that demonstrate a concept for a {sup 235}U flow and enrichment monitor (FEMO) based on passive measurements of process equipment in gaseous centrifuge enrichment plants (GCEPs). The primary goal of the FEMO is to prevent, without using pipe penetrations or active interrogation with external sources, the production and diversion of undeclared nuclear material. This FEMO concept utilizes: (1) calibrated measurements of {sup 235}U density in cascade headers, and (2) measurements of pump inlet pressure and volumetric flow rate, which are correlated to the electrical power consumed by the GCEP pumps that transport UF{sub 6} from the cascade to the condensation cylinders. The {sup 235}U density is measured by counting 186 keV emissions using a NaI gamma detector located upstream of the pump. The pump inlet pressure and volumetric flow rate are determined using a correlation that is a function of the measured pump operational parameters (e.g., electric power consumption and rotational frequency) and the pumping configuration. The concept has been demonstrated in a low-pressure flow loop at Oak Ridge National Laboratory.

March-Leuba, Jose A [ORNL] [ORNL; Uckan, Taner [ORNL] [ORNL

2010-01-01

308

Isotopically Enriched Films and Nanostructures by Ultrafast Pulsed Laser Deposition  

SciTech Connect

This project involved a systematic study to apply newly discovered isotopic enrichment effects in laser ablation plumes to the fabrication of isotopically engineered thin films, superlattices, and nanostructures. The approach to this program involved using ultrafast lasers as a method for generating ablated plasmas that have preferentially structured isotopic content in the body of the ablation plasma plumes. In examining these results we have attempted to interpret the observations in terms of a plasma centrifuge process that is driven by the internal electro-magnetic fields of the plasma itself. The research plan involved studying the following phenomena in regard to the ablation plume and the isotopic mass distribution within it: (1) Test basic equations of steady state centrifugal motion in the ablation plasma. (2) Investigate angular distribution of ions in the ablation plasmas. (3) Examine interactions of plasma ions with self-generated magnetic fields. (3) Investigate ion to neutral ratios in the ablation plasmas. (5) Test concepts of plasma pumping. (6) Fabricate isotopically enriched nanostructures.

Peter Pronko

2004-12-13

309

Enrichments of Cellulolytic Communities from Diverse Natural Sources Using a Novel Selection System  

NASA Astrophysics Data System (ADS)

In order to ensure a sustainable future and curb carbon dioxide emissions from the combustion of fossil fuels, it is imperative to develop a cost-competitive manufacturing process for an alternative liquid fuel with low life cycle greenhouse gas emissions. A potential route towards this sustainable future is the large-scale production of fuels derived from plant biomass, biofuels. A major step for the biological conversion of biomass to fuel is the solubilization and utilization of cellulose. However, lignocellulose is a recalcitrant material, and has evolved to resist microbial degradation. Studying cellulolytic communities from nature can reveal the mechanisms by which organisms can utilize lignocellulose, and also reveal the conditions that facilitate the fastest possible rates of cellulose utilization. This thesis used an Automated Repetitive Batch (ARB) system to perform enrichments of cellulolytic communities to test if cellulolytic communities from diverse sources could be reproducibly enriched for rapid cellulose utilization. This thesis first developed a robust method for reproducibly enriching cellulolytic communities in the ARB system with a single environmental source. Using this method, this research then investigated if cellulolytic communities could be enriched for rapid cellulose utilization from different inoculum sources. In all reproducible enrichments, this thesis then confirmed the use of carbon dioxide as a real time proxy for cellulose utilization based on end product analysis. This thesis showed that the ARB system could yield cellulolytic communities capable of rapid cellulose utilization from diverse environmental sources, and laid a strong foundation for determining whether or not these different sources can be enriched to yield functionally similar cellulolytic communities. The work from this thesis also suggests that fermentation conditions, rather than source material, play a more important role in determining enriched community performance.

Ludwig, Evan Joel

310

Modeling of UF{sub 6} enrichment with gas centrifuges for nuclear safeguards activities  

SciTech Connect

The physical modeling of uranium isotopes ({sup 235}U, {sup 238}U) separation process by centrifugation of is a key aspect for predicting the nuclear fuel enrichment plant performances under surveillance by the Nuclear Safeguards Authorities. In this paper are illustrated some aspects of the modeling of fast centrifuges for UF{sub 6} gas enrichment and of a typical cascade enrichment plant with the Theoretical Centrifuge and Cascade Simulator (TCCS). The background theory for reproducing the flow field characteristics of a centrifuge is derived from the work of Cohen where the separation parameters are calculated using the solution of a differential enrichment equation. In our case we chose to solve the hydrodynamic equations for the motion of a compressible fluid in a centrifugal field using the Berman - Olander vertical velocity radial distribution and the solution was obtained using the Matlab software tool. The importance of a correct estimation of the centrifuge separation parameters at different flow regimes, lies in the possibility to estimate in a reliable way the U enrichment plant performances, once the separation external parameters are set (feed flow rate and feed, product and tails assays). Using the separation parameters of a single centrifuge allow to determine the performances of an entire cascade and, for this purpose; the software Simulink was used. The outputs of the calculation are the concentrations (assays) and the flow rates of the enriched (product) and depleted (tails) gas mixture. These models represent a valid additional tool, in order to verify the compliance of the U enrichment plant operator declarations with the 'on site' inspectors' measurements.

Mercurio, G.; Peerani, P.; Richir, P.; Janssens, W.; Eklund, G. [European Commission, Joint Research Centre, Institute for Transuranium Elements Via Fermi, 2749-TP181,20127 Ispra (Italy)

2012-09-26

311

Modeling of UF6 enrichment with gas centrifuges for nuclear safeguards activities  

NASA Astrophysics Data System (ADS)

The physical modeling of uranium isotopes (235U, 238U) separation process by centrifugation of is a key aspect for predicting the nuclear fuel enrichment plant performances under surveillance by the Nuclear Safeguards Authorities. In this paper are illustrated some aspects of the modeling of fast centrifuges for UF6 gas enrichment and of a typical cascade enrichment plant with the Theoretical Centrifuge and Cascade Simulator (TCCS). The background theory for reproducing the flow field characteristics of a centrifuge is derived from the work of Cohen [1] where the separation parameters are calculated using the solution of a differential enrichment equation. In our case we chose to solve the hydrodynamic equations for the motion of a compressible fluid in a centrifugal field using the Berman - Olander vertical velocity radial distribution [2] and the solution was obtained using the Matlab software tool [3]. The importance of a correct estimation of the centrifuge separation parameters at different flow regimes, lies in the possibility to estimate in a reliable way the U enrichment plant performances, once the separation external parameters are set (feed flow rate and feed, product and tails assays)[4]. Using the separation parameters of a single centrifuge allow to determine the performances of an entire cascade and, for this purpose; the software Simulink [3] was used. The outputs of the calculation are the concentrations (assays) and the flow rates of the enriched (product) and depleted (tails) gas mixture. These models represent a valid additional tool, in order to verify the compliance of the U enrichment plant operator declarations with the "on site" inspectors' measurements.

Mercurio, G.; Peerani, P.; Richir, P.; Janssens, W.; Eklund, G.

2012-09-01

312

Enriched biodiversity data as a resource and service  

PubMed Central

Abstract Background: Recent years have seen a surge in projects that produce large volumes of structured, machine-readable biodiversity data. To make these data amenable to processing by generic, open source “data enrichment” workflows, they are increasingly being represented in a variety of standards-compliant interchange formats. Here, we report on an initiative in which software developers and taxonomists came together to address the challenges and highlight the opportunities in the enrichment of such biodiversity data by engaging in intensive, collaborative software development: The Biodiversity Data Enrichment Hackathon. Results: The hackathon brought together 37 participants (including developers and taxonomists, i.e. scientific professionals that gather, identify, name and classify species) from 10 countries: Belgium, Bulgaria, Canada, Finland, Germany, Italy, the Netherlands, New Zealand, the UK, and the US. The participants brought expertise in processing structured data, text mining, development of ontologies, digital identification keys, geographic information systems, niche modeling, natural language processing, provenance annotation, semantic integration, taxonomic name resolution, web service interfaces, workflow tools and visualisation. Most use cases and exemplar data were provided by taxonomists. One goal of the meeting was to facilitate re-use and enhancement of biodiversity knowledge by a broad range of stakeholders, such as taxonomists, systematists, ecologists, niche modelers, informaticians and ontologists. The suggested use cases resulted in nine breakout groups addressing three main themes: i) mobilising heritage biodiversity knowledge; ii) formalising and linking concepts; and iii) addressing interoperability between service platforms. Another goal was to further foster a community of experts in biodiversity informatics and to build human links between research projects and institutions, in response to recent calls to further such integration in this research domain. Conclusions: Beyond deriving prototype solutions for each use case, areas of inadequacy were discussed and are being pursued further. It was striking how many possible applications for biodiversity data there were and how quickly solutions could be put together when the normal constraints to collaboration were broken down for a week. Conversely, mobilising biodiversity knowledge from their silos in heritage literature and natural history collections will continue to require formalisation of the concepts (and the links between them) that define the research domain, as well as increased interoperability between the software platforms that operate on these concepts. PMID:25057255

Balech, Bachir; Beard, Niall; Blissett, Matthew; Brenninkmeijer, Christian; van Dooren, Tom; Eades, David; Gosline, George; Groom, Quentin John; Hamann, Thomas D.; Hettling, Hannes; Hoehndorf, Robert; Holleman, Ayco; Hovenkamp, Peter; Kelbert, Patricia; King, David; Kirkup, Don; Lammers, Youri; DeMeulemeester, Thibaut; Mietchen, Daniel; Miller, Jeremy A.; Mounce, Ross; Nicolson, Nicola; Page, Rod; Pawlik, Aleksandra; Pereira, Serrano; Penev, Lyubomir; Richards, Kevin; Sautter, Guido; Shorthouse, David Peter; Tähtinen, Marko; Weiland, Claus; Williams, Alan R.; Sierra, Soraya

2014-01-01

313

Characterization of the n-3 polyunsaturated fatty acid enrichment in laying hens fed an extruded flax enrichment source.  

PubMed

The time required to reach a plateau of n-3 polyunsaturated fatty acid (PUFA) concentration in plasma and egg yolk and dynamics of the enrichment process were examined in laying hens. A group of 75 Lohmann White Leghorn layers (65 wk) were fed one of 3 diets: control, moderate, or high n-3 PUFA-enriched diet for 18 d. Diets provided similar ME and CP and contained 0, 7.5%, or 15% LinPRO (source of n-3 PUFA), respectively. Prior to dietary treatment, baseline values were established for the BW, fatty acid composition in egg yolk on a whole-egg basis, and in plasma. These measurements were repeated at 6, 12, and 18 d of feeding. Enzymatic conversion rates of linolenic acid (LNA) to long-chain fatty acids were calculated. Data were analyzed with Proc Mixed of SAS, and broken stick analysis was used to determine n-3 PUFA plateau using the NLIN procedure of SAS (P < 0.05). The total egg yolk n-3 PUFA reached a plateau of 343.7 mg/egg and 272.9 mg/egg after 6.6 and 5.9 d on the high and moderate diets, respectively. In blood plasma, the n-3 PUFA concentrations reached saturation in 7.2 d with 0.93 mg/mL and 0.67 mg/mL on high and moderate diets, respectively. The transfer efficiency of total n-3 PUFA from the diet to the egg yolk was calculated as 55.6% in control birds, 30.5% in moderate birds, and 22.2% in high birds, demonstrating reduced transfer efficiency of n-3 PUFA as inclusion in the feed increases. Final egg yolk n-3 PUFA concentrations had a CV of 16.5% compared with 28.5% for plasma. After 12 d, the long-chain n-3 PUFA [eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA)] were significantly higher in egg yolk from hens on the moderate and high enriched diets compared with those from hens fed the control diet, whereas in plasma values did not differ. Broken stick analysis of egg enrichment indicated that high birds reached the target threshold of 300 mg of total n-3 PUFA/egg in 5 d. A significant increase in EPA, DPA, and DHA and reduction in arachidonic acid content in egg yolks from hens fed enriched diets compared with the control diet confirms competition for enzymes during postabsorptive modification of these fatty acids. This work contributes to the understanding of individual hen effects on n-3 PUFA absorption and the effect of level of dietary enrichment with an extruded flax product on final yolk n-3 PUFA concentration. PMID:22700520

Nain, S; Renema, R A; Korver, D R; Zuidhof, M J

2012-07-01

314

Measurement of the enrichment of uranium in the pipework of a gas centrifuge enrichment plant  

SciTech Connect

The US and UK have been separately working on the development of a NDA instrument to determine the enrichment of gaseous UF/sub 6/ at low pressures in cascade header pipework in line with the conclusions of the Hexapartite Safeguards Project viz. the instrument is capable of making a ''go/no go'' decision of whether the enrichment is less than/greater than 20%. Recently, there has been a series of very useful technical exchanges of ideas and information between the two countries. This has led to a technical formulation for such an instrumentation based on ..gamma..-ray spectrometry which, although plant-specific in certain features, nevertheless is based on the same physical principles. Experimental results from commercially operating enrichment plants are very encouraging and indicate that a complete measurement including set up time on the pipe should be attainable in about 30 minutes when measuring pipes of diameter around 110 mm. 5 refs., 4 figs.

Packer, T.W.; Lees, E.W.; Close, D.; Nixon, K.V.; Pratt, J.C.; Strittmatter, R.

1985-01-01

315

Application of atomic vapor laser isotope separation to the enrichment of mercury  

SciTech Connect

Workers at GTE/Sylvania have shown that the efficiency of fluorescent lighting may be markedly improved using mercury that has been enriched in the /sup 196/Hg isotope. A 5% improvement in the efficiency of fluorescent lighting in the United States could provide a savings of approx. 1 billion dollars in the corresponding reduction of electrical power consumption. We will discuss the results of recent work done at our laboratory to develop a process for enriching mercury. The discussion will center around the results of spectroscopic measurements of excited state lifetimes, photoionization cross sections and isotope shifts. In addition, we will discuss the mercury separator and supporting laser mesurements of the flow properties of mercury vapor. We will describe the laser system which will provide the photoionization and finally discuss the economic details of producing enriched mercury at a cost that would be attractive to the lighting industry.

Crane, J.K.; Erbert, G.V.; Paisner, J.A.; Chen, H.L.; Chiba, Z.; Beeler, R.G.; Combs, R.; Mostek, S.D.

1986-09-01

316

Enriching semantic knowledge bases for opinion mining in big data applications.  

PubMed

This paper presents a novel method for contextualizing and enriching large semantic knowledge bases for opinion mining with a focus on Web intelligence platforms and other high-throughput big data applications. The method is not only applicable to traditional sentiment lexicons, but also to more comprehensive, multi-dimensional affective resources such as SenticNet. It comprises the following steps: (i) identify ambiguous sentiment terms, (ii) provide context information extracted from a domain-specific training corpus, and (iii) ground this contextual information to structured background knowledge sources such as ConceptNet and WordNet. A quantitative evaluation shows a significant improvement when using an enriched version of SenticNet for polarity classification. Crowdsourced gold standard data in conjunction with a qualitative evaluation sheds light on the strengths and weaknesses of the concept grounding, and on the quality of the enrichment process. PMID:25431524

Weichselbraun, A; Gindl, S; Scharl, A

2014-10-01

317

Enriching semantic knowledge bases for opinion mining in big data applications  

PubMed Central

This paper presents a novel method for contextualizing and enriching large semantic knowledge bases for opinion mining with a focus on Web intelligence platforms and other high-throughput big data applications. The method is not only applicable to traditional sentiment lexicons, but also to more comprehensive, multi-dimensional affective resources such as SenticNet. It comprises the following steps: (i) identify ambiguous sentiment terms, (ii) provide context information extracted from a domain-specific training corpus, and (iii) ground this contextual information to structured background knowledge sources such as ConceptNet and WordNet. A quantitative evaluation shows a significant improvement when using an enriched version of SenticNet for polarity classification. Crowdsourced gold standard data in conjunction with a qualitative evaluation sheds light on the strengths and weaknesses of the concept grounding, and on the quality of the enrichment process. PMID:25431524

Weichselbraun, A.; Gindl, S.; Scharl, A.

2014-01-01

318

A targeted enrichment strategy for massively parallel sequencing of angiosperm plastid genomes1  

PubMed Central

• Premise of the study: We explored a targeted enrichment strategy to facilitate rapid and low-cost next-generation sequencing (NGS) of numerous complete plastid genomes from across the phylogenetic breadth of angiosperms. • Methods and Results: A custom RNA probe set including the complete sequences of 22 previously sequenced eudicot plastomes was designed to facilitate hybridization-based targeted enrichment of eudicot plastid genomes. Using this probe set and an Agilent SureSelect targeted enrichment kit, we conducted an enrichment experiment including 24 angiosperms (22 eudicots, two monocots), which were subsequently sequenced on a single lane of the Illumina GAIIx with single-end, 100-bp reads. This approach yielded nearly complete to complete plastid genomes with exceptionally high coverage (mean coverage: 717×), even for the two monocots. • Conclusions: Our enrichment experiment was highly successful even though many aspects of the capture process employed were suboptimal. Hence, significant improvements to this methodology are feasible. With this general approach and probe set, it should be possible to sequence more than 300 essentially complete plastid genomes in a single Illumina GAIIx lane (achieving ?50× mean coverage). However, given the complications of pooling numerous samples for multiplex sequencing and the limited number of barcodes (e.g., 96) available in commercial kits, we recommend 96 samples as a current practical maximum for multiplex plastome sequencing. This high-throughput approach should facilitate large-scale plastid genome sequencing at any level of phylogenetic diversity in angiosperms. PMID:25202518

Stull, Gregory W.; Moore, Michael J.; Mandala, Venkata S.; Douglas, Norman A.; Kates, Heather-Rose; Qi, Xinshuai; Brockington, Samuel F.; Soltis, Pamela S.; Soltis, Douglas E.; Gitzendanner, Matthew A.

2013-01-01

319

The Enrichment of the Intracluster Medium  

E-print Network

The enrichment of the intracluster medium (ICM) of galaxy clusters, within the framework of the supernovae-driven wind model for elliptical galaxies, has been considered under two extreme assumptions regarding the binding energy-mass-radius relations. Unless the binding energy at the time of wind commencement, for a given galactic mass, was a factor of approximately five lower than that predicted by the present-day relation, at most 20% of the ICM gas could have originated within the cluster ellipticals themselves, the remainder being of primordial origin.

Brad K. Gibson; Francesca Matteucci

1996-12-13

320

Oxygen Enriched Combustion System Performance Study  

E-print Network

OXYGEN ENRICHED COr~USTION A. R. ABELE, Y. KWAN, S. L. CHEN Energy and Environmental Research Corporation Irvine, California ABSTRACT The objective of this study is to identify pot~ntial industri~l applications for which oxygen enr... burner designs have been conducted at scales of 1 x 10 6 Btu/hr and 10 x 10 6 Btu/hr. The burners represent both conven tional air fired designs and oxygen/fuel burners designed primarily for very high oxygen levels. The results of these tests...

Chen, S. L.; Kwan, Y.; Abele, A. R.; Silver, L. S.; Kobayashi, H.

321

Hydrogen-enrichment-concept preliminary evaluation  

NASA Technical Reports Server (NTRS)

A hydrogen-enriched fuels concept for automobiles is described and evaluated in terms of fuel consumption and engine exhaust emissions through multicylinder (V-8) automotive engine/hydrogen generator tests, single cylinder research engine (CFR) tests, and hydrogen-generator characterization tests. Analytical predictions are made of the fuel consumption and NO/sub x/ emissions which would result from anticipated engine improvements. The hydrogen-gas generator, which was tested to quantify its thermodynamic input-output relationships was used for integrated testing of the V-8 engine and generator.

Ecklund, E. E.

1975-01-01

322

Active interrogation of highly enriched uranium  

NASA Astrophysics Data System (ADS)

Safeguarding special nuclear material (SNM) in the Department of Energy Complex is vital to the national security of the United States. Active and passive nondestructive assays are used to confirm the presence of SNM in various configurations ranging from waste to nuclear weapons. Confirmation measurements for nuclear weapons are more challenging because the design complicates the detection of a distinct signal for highly enriched uranium. The emphasis of this dissertation was to investigate a new nondestructive assay technique that provides an independent and distinct signal to confirm the presence of highly enriched uranium (HEU). Once completed and tested this assay method could be applied to confirmation measurements of nuclear weapons. The new system uses a 14-MeV neutron source for interrogation and records the arrival time of neutrons between the pulses with a high efficiency detection system. The data is then analyzed by the Feynman reduced variance method. The analysis determined the amount of correlation in the data and provided a unique signature of correlated fission neutrons. Measurements of HEU spheres were conducted at Los Alamos with the new system. Then, Monte Carlo calculations were performed to verify hypothesis made about the behavior of the neutrons in the experiment. Comparisons of calculated counting rates by the Monte Carlo N-Particle Transport Code (MCNP) were made with the experimental data to confirm that the measured response reflected the desired behavior of neutron interactions in the highly enriched uranium. In addition, MCNP calculations of the delayed neutron build-up were compared with the measured data. Based on the results obtained from this dissertation, this measurement method has the potential to be expanded to include mass determinations of highly enriched uranium. Although many safeguards techniques exist for measuring special nuclear material, the number of assays that can be used to confirm HEU in shielded systems is limited. These assays also rely on secondary characteristics of the material to be measured. A review of the nondestructive techniques with potential applications for nuclear weapons confirmatory measurements were evaluated with summaries of the pros and cons involved in implementing the methods at production type facilities.

Fairrow, Nannette Lea

323

Systems approach used in the Gas Centrifuge Enrichment Plant  

SciTech Connect

A requirement exists for effective and efficient transfer of technical knowledge from the design engineering team to the production work force. Performance-Based Training (PBT) is a systematic approach to the design, development, and implementation of technical training. This approach has been successfully used by the US Armed Forces, industry, and other organizations. The advantages of the PBT approach are: cost-effectiveness (lowest life-cycle training cost), learning effectiveness, reduced implementation time, and ease of administration. The PBT process comprises five distinctive and rigorous phases: Analysis of Job Performance, Design of Instructional Strategy, Development of Training Materials and Instructional Media, Validation of Materials and Media, and Implementation of the Instructional Program. Examples from the Gas Centrifuge Enrichment Plant (GCEP) are used to illustrate the application of PBT.

Rooks, W.A. Jr.

1982-01-01

324

Enrichment of deeply penetrating waves in disordered media  

E-print Network

Waves incident to a highly scattering medium are incapable of penetrating deep into the medium due to the diffusion process induced by multiple scattering. This poses a fundamental limitation to optically imaging, sensing, and manipulating targets embedded in opaque scattering layers such as biological tissues. One strategy for mitigating the shallow wave penetration is to exploit eigenmodes with anomalously high transmittance existing in any disordered medium. When waves are coupled to these eigenmodes, strong constructive wave interference enhances deeply penetrating waves. However, finding such eigenmodes has been a challenging task due to the complexity of disordered media. In this Letter, we present an iterative wavefront control method that selectively enriches the coupling of incident beam to high-transmission eigenmodes. Specifically, we refined the high-transmission eigenmodes from an arbitrary initial wave by either maximizing transmitted wave intensity or minimizing reflected wave intensity. Using ...

Choi, Wonjun; Kim, Donggyu; Yoon, Changhyeong; Fang-Yen, Christopher; Park, Q-Han; Choi, Wonshik

2013-01-01

325

Galaxy formation and chemical enrichment using cosmological hydrodynamic simulations  

NASA Astrophysics Data System (ADS)

Structure formation in the Universe is inherently a nonlinear physical process, and the field of computational cosmology aims to study its time evolution throughout the history of the Universe as self-consistently as possible. Cosmological hydrodynamic simulations have gone through two major revolutions over the last two decades, and now starting to go through the third one via more frequent usage of zoom-in technique. In the first part of this article, I briefly review the history of computational cosmology. In the second part, I discuss the results of recent work on the feedback effects and chemical enrichment, which is one of the main topics of this OMEG12 conference. Finally, I describe the new steps that the numerical community is taking; namely the numerical simulation comparison projects such as the AGORA project.

Nagamine, Kentaro

2014-05-01

326

Effects of N and P enrichment on competition between phytoplankton and benthic algae in shallow lakes: a mesocosm study.  

PubMed

Competition for resources between coexisting phytoplankton and benthic algae, but with different habitats and roles in functioning of lake ecosystems, profoundly affects dynamics of shallow lakes in the process of eutrophication. An experiment was conducted to test the hypothesis that combined enrichment with nitrogen (N) and phosphorus (P) would be a greater benefit to phytoplankton than benthic algae. The growth of phytoplankton and benthic algae was measured as chlorophyll a (Chl a) in 12 shallow aquatic mesocosms supplemented with N, P, or both. We found that enrichment with N enhanced growth of benthic algae, but not phytoplankton. P enrichment had a negative effect on benthic algal growth, and no effect on the growth of phytoplankton. N+P enrichment had a negative effect on benthic algae, but enhanced the growth of phytoplankton, thus reducing the proportion of benthic algae contributing to the combined biomass of these two groups of primary producers. Thus, combined N+P enrichment is more favorable to phytoplankton in competition with benthic algae than enrichment with either N or P alone. Our study indicates that combined enrichment with N+P promotes the dominance of phytoplankton over benthic algae, with consequences for the trophic dynamics of shallow lake ecosystems. PMID:25304240

Zhang, Xiufeng; Mei, Xueying; Gulati, Ramesh D; Liu, Zhengwen

2015-03-01

327

75 FR 62895 - Notice of Availability of Safety Evaluation Report; AREVA Enrichment Services LLC, Eagle Rock...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Enrichment Services LLC, Eagle Rock Enrichment Facility, Bonneville County...Manager, Advanced Fuel Cycle, Enrichment, and Uranium Conversion, Division of Fuel...material in a gas centrifuge uranium enrichment facility. The applicant...

2010-10-13

328

75 FR 16869 - Areva Enrichment Services, LLC; Establishment of Atomic Safety and Licensing Board  

Federal Register 2010, 2011, 2012, 2013, 2014

...application of Areva Enrichment Services, LLC for a...and to enrich natural uranium to a maximum of 5 percent...known as the Eagle Rock Enrichment Facility that would...authorization to construct a uranium enrichment facility, a...

2010-04-02

329

OnTarget: A tool for analysing enrichment data derived from next generation sequencing  

Microsoft Academic Search

We have developed OnTarget, a pipeline which is designed to evaluate next generation sequencing data after sub-genomic enrichment. It is able to process single-end and paired-end sequence reads as well as single-end bisulfite data. Sequence reads can be sorted by barcodes and are mapped against the genome. Only reads which map once are processed, subsequently removing duplicate reads and finally

Agnes Hotz-Wagenblatt; Ilia Kats; Karl-Heinz Glatting; Maren Scharfenberger-Schmeer; Berit Haldemann

2011-01-01

330

Rare-earth elements enrichment of Pacific seafloor sediments: the view from volcanic islands of Polynesia  

NASA Astrophysics Data System (ADS)

Rare-earth elements (REEs) are key metals for «green» technologies such as energy saving lamps or permanent magnets used in, e.g., wind turbines, hard disk drives, portable phone or electric or hybrid vehicles. Since several years, world demand for these metals is therefore drastically increasing. The quasi-monopolistic position of China, which produces around 95 % of global REEs production, generates risks for the industries that depend on a secure supply of REEs. In response, countries are developing and diversifying their supply sources, with new mining projects located outside China and efforts in the area of REEs recycling. Most of these projects focus on deposits related to carbonatites and alkaline-peralkaline magmatism, which are generally enriched in light REEs (LREEs) compared to the heavy REEs (HREEs)-enriched deposits of the ion-adsorption types, located in southern China. However, a recent study revealed new valuable resources corresponding to seafloor sediments located in the south-eastern and north-central Pacific. The deep-sea mud described by these authors show a higher HREE/LREE ratio than ion-adsorption deposits, a feature which significantly increases their economic interest. The authors suggest mid-ocean ridge hydrothermal activity as an explanation to this anomalous enrichment. However, several contributions have documented considerable REEs enrichment in basalts and peridotitic xenoliths from French Polynesia. Several arguments have been exposed in favour of a supergene origin, with a short migration, suggesting that REEs were collected from weathered basalts. The Tahaa volcanic island (Sous-le-Vent Island, Society Archipelago, French Polynesia) is the first location where such enrichment has been described. New petrographic and mineralogical investigations confirm a supergene mobilization of this abnormal occurrence. REE-bearing minerals (mainly phosphates of the rhabdophane group) are primarily located within basalt vesicles but also in crack that cross-cut the calcite filling the vesicles or the volcanic glass. They are also closely associated with Ni-Mg bearing phyllosilicates, which appear to nucleate from alteration of olivine and clinopyroxenes. Further investigations are done to evidence and confirm an anterior magmatic enrichment. On the basis of these observations, we believe that the anomalous enrichment observed in seafloor sediments could derive from abnormally-rich provinces corresponding to aerial basaltic formations from oceanic islands primarily enriched during weathering processes (Melleton et al., 2014). Melleton et al. (2014). Rare-earth elements enrichment of Pacific sea-floor sediments: the view from volcanic islands of Polynesia. In preparation.

Melleton, Jérémie; Tuduri, Johann; Pourret, Olivier; Bailly, Laurent; Gisbert, Thierry

2014-05-01

331

Preferences of Minipigs for Environmental Enrichment Objects  

PubMed Central

The minipig is an increasingly popular species for use in behavioral and toxicologic studies. As a result, quantification of environmental enrichment preferences for this species is especially important. We exposed 6 individually housed prepubertal female Yucatan minipigs to 1 of 3 different objects on a rotating schedule: 2 sessions with a hard plastic ball (diameter, 21.0 cm), and 3 sessions each with a large plastic apple (diameter, 22.5 cm) and a soft rubber cone (height, 48.0 cm). Objects were changed every 4 to 5 d. The initial 15 min after each object change was recorded, and duration of object interaction and other behaviors (activity and interaction with the food bowl) were measured. Results indicated significantly longer interactions with the cone (mean ± SE, 282 ± 54 s) than the ball (14 ± 3 s). Interactions with the apple (66 ± 18 s) and ball did not differ significantly. Interactions with the apple decreased across the 3 sessions, whereas interaction with the cone remained high for most minipigs over the 3 sessions. Duration of activity appeared to be inversely correlated with duration of object interaction (that is, the longer the subject interacted with the object, the less it engaged in nonobject activity). These results provide valuable and practical information on the features of objects that minipigs appear to prefer and offer suggestions for future studies evaluating environmental enrichment paradigms with individually housed minipigs. PMID:19653948

Smith, Melody E; Gopee, Neera V; Ferguson, Sherry A

2009-01-01

332

The Art of Schoolwide Enrichment: A Resource Guidebook for Teachers, Enrichment Specialists, and Principals  

ERIC Educational Resources Information Center

In this companion to "Opening Doors", Friedman and Webb provide more helpful, hand-on tips for bringing SEM to life in your school. Readers learn, step-by-step, how to create a schedule that includes a weekly E-Slot for enrichment learning experiences as well as ideas for injecting interest-based experiences into the E-Slot, regular curriculum,…

Friedman, Nora G.; Webb, Michele

2007-01-01

333

Nutrient enrichment and the role of salt marshes in the Tagus estuary (Portugal)  

NASA Astrophysics Data System (ADS)

Eutrophication is one of the most common impacts of nutrient enrichment on coastal ecosystems. Since there is a wide ecosystem response variety in scale, intensity and impact to nutrient enrichment, the loading required to produce eutrophication symptoms to each system is also variable. In estuaries and coastal zones salt marsh primary producers have received less attention, mainly because salt marsh dominated systems are considered less sensitive to nutrient enrichment and, for that reason, their response is slower and more difficult to quantify. Salt marshes have been considered as major attenuators of the effects of nitrogen enrichment in several coastal systems, and are indicated as a measure of the system susceptibility to nutrient enrichment. The main goal of the present work is to discuss the role of salt marsh vegetation in the nutrient dynamics of coastal systems and in the nutrient enrichment process. For these purposes salt marsh vegetation growth in the Tagus estuary is described through a mathematical model which includes the simulation of the nutrient dynamics through the sediment-water interface and the uptake kinetics by the vascular plants. An analysis of the role of salt marsh vegetation on the nutrient dynamics of the Tagus estuary is carried out through the discussion of the model results and comparison with data obtained for other primary producers in the system. The results indicate that C 4 salt marsh plants have the highest productivity, followed by seaweeds. The total net production of salt marsh plants and is about 12,600 ton C yr -1, accounting for 25% of the total primary production within the system.

Simas, T. C.; Ferreira, J. G.

2007-11-01

334

Cenozoic magmatism in the South China Basin: Decompression melting and implications of an enriched mantle source  

SciTech Connect

A widespread eposide of interplate volcanism followed the cessation of seafloor spreading in the South China Basin (SCB), affecting the South China Sea, and fringing areas of southern China and Indochina. Geochemical data for basalts from South China Sea islands and seamounts, Hainan Island, and Taiwan define an enriched (Dupal-like) mantle domain yielding oceanic island basalt (OIB) suites with {Delta}7/4Pb = 2-13, {Delta}8/4Pb = 45-73, {sup 87}Sr/{sup 86}Sr > {approximately}0.70325, Th/Ta > 2, and Th/Ba > 0.02. Opening of the SCB resulted from disaggregation of the South China block in response to the Indo-Eurasian collision, a process involving at least one seafloor spreading episode, terminated by collision of microcontinents with the Philippines and Borneo. The lack of precursive flood basalt suggests that active mantle upwelling was not involved and that melting was a passive effect of lithosphere stretching. However, while mantle decompression at ambient stretching factors ({approximately}1.7-2.5) appears to permit melting on the observed scale, the enriched source may preclude such a simple mantle dynamic. Three alternatives are considered: (1) passive melting of a mature metasomatised boundary layer, (2) active melting of thermally eroded subcontinental lithosphere (deep enrichment) or metasomatised boundary layer (shallow enrichment), and (3) relict diapirs of pre-SCB and/or Java trench subduction slabs (intermediate/deep enrichment). These models are evaluated in terms of chemical and isotopic mass balances associated with the generation and movement of small melt fractions in depleted, nondepleted, and enriched mantle.

Flower, M.F.J.; Kan Tu; Ming Zhang (Univ. of Illinois, Chicago (USA)); Guanghong Xie (Institute of Geochemistry, Guangzhou (China))

1990-06-01

335

Isotope Enrichment Detection by Laser Ablation - Dual Tunable Diode Laser Absorption Spectrometry  

SciTech Connect

The rapid global expansion of nuclear energy is motivating the expedited development of new safeguards technology to mitigate potential proliferation threats arising from monitoring gaps within the uranium enrichment process. Current onsite enrichment level monitoring methods are limited by poor sensitivity and accuracy performance. Offsite analysis has better performance, but this approach requires onsite hand sampling followed by time-consuming and costly post analysis. These limitations make it extremely difficult to implement comprehensive safeguards accounting measures that can effectively counter enrichment facility misuse. In addition, uranium enrichment by modern centrifugation leads to a significant proliferation threat, since the centrifuge cascades can quickly produce a significant quantity of highly enriched uranium (HEU). The Pacific Northwest National Laboratory is developing an engineered safeguards approach having continuous aerosol particulate collection and uranium isotope analysis to provide timely detection of HEU production in a low enriched uranium facility. This approach is based on laser vaporization of aerosol particulate samples, followed by wavelength tuned laser diode spectroscopy, to characterize the 235U/238U isotopic ratio by subtle differences in atomic absorption wavelengths arising from differences in each isotope’s nuclear mass, volume, and spin (hyperfine structure for 235U). Environmental sampling media is introduced into a small, reduced pressure chamber, where a focused pulsed laser vaporizes a 10 to 20-µm sample diameter. The ejected plasma forms a plume of atomic vapor. A plume for a sample containing uranium has atoms of the 235U and 238U isotopes present. Tunable diode lasers are directed through the plume to selectively excite each isotope and their presence is detected by monitoring absorbance signals on a shot-to-shot basis. Single-shot detection sensitivity approaching the femtogram range and abundance uncertainty less than 10% have been demonstrated with measurements on surrogate materials. In this paper we present measurement results on samples containing background materials (e.g., dust, minerals, soils) laced with micron-sized target particles having isotopic ratios ranging from 1 to 50%.

Anheier, Norman C.; Bushaw, Bruce A.

2009-07-01

336

Biomineralization of strontianite(SrCO3) by aerobic microorganisms enriched from rhodoliths  

NASA Astrophysics Data System (ADS)

The transport and fate of trace metals and radionuclides in natural environments are controlled by physical, chemical, and microbiological processes. Especially, microbially induced precipitation of carbonates has drawn much attention in recent decades because of its numerous implications such as atmospheric CO2 fixation through mineral carbonation and solid phase capture of inorganic contaminants. The objectives of this study were to investigate the potential for microbially induced precipitation of strontianite (SrCO3) using microorganisms enriched from rhodoliths and to identify mineralogical characteristics of the precipitates of strontianite. Carbonate forming microorganisms were enriched from rhodoliths, which were sampled at Seogwang-ri coast in the western part of Wu Island, Jeju-do, Korea. Microorganisms enriched from rhodoliths were aerobically cultured at 25? in D-1 media containing 30 mM Sr-acetate, and the microorganisms were analyzed by 16S rRNA gene DGGE analysis to confirm microbial diversity. Mineralogical characteristics of the carbonate minerals precipitated by the enriched microorganisms were determined by XRD, TEM-EDS, and SEM-EDS analyses. A 16S rRNA sequence analysis showed the enriched microorganisms contained carbonate forming microorganisms such as Proteus mirailis. The enriched microorganisms precipitated carbonate minerals using D-1 media containing 30 mM Sr-acetate and mineralogy of the precipitate was strontianite (SrCO3). SEM/TEM-EDS analyses showed that the strontianite formed by the microorganisms had a spherical shape and consisted of mainly Sr, O and C. TEM-EDS analyses showed that the strontianite formed by the microorganisms had a rhombohedron shape and consisted of mainly Sr, O and C. These results indicate that the microorganisms induce precipitation of strontianite (SrCO3) on the cell walls and EPS via the accumulation of Sr ions on the cells. Therefore, microbial precipitation of carbonate minerals may play one of important roles in immobilization of metals and radionuclides in natural environments.

Kang, S.; Roh, Y.

2012-12-01

337

Melt CO2 Enrichment by Permeable Flow and Resorption  

NASA Astrophysics Data System (ADS)

Matrix and melt inclusion glasses commonly have CO2/H2O ratio values that are too high to be explained by standard closed- or open-system degassing. We explore the possibility of increasing CO2/H2O in melts through cycles of decompression, permeability development and gas flow, followed by repressurization and volatile resorption. As a case study we consider the spring and summer 1980 eruptions at Mt. St. Helens. Glasses from the climactic May 18 eruption show the least CO2 enrichment whereas the next eruption, on May 25, as well as several other eruptions, show substantial CO2 enrichment. We suggest that the episodic nature of the eruption sequence could have caused portions of the magma to experience multiple pressure cycles leading to overall increases in the CO2/H2O content of the melt. The proposed cycle begins with magma containing isolated bubbles with gas pressures similar to the surrounding melt. Depressurization of the magma (e.g., by edifice collapse and eruption of more shallow magma) causes sufficient vesiculation for bubbles to touch and form apertures, creating a connected network of gas. As gas escapes, the pressure of the vertically-connected gas falls from the melt pressure (related to the weight of magma above) down towards a gas-static pressure. The resulting discrepancy between the melt and gas pressures will cause 1) volatile diffusion from the melt into the relatively low-pressure bubble phase, and 2) bubble collapse and thus permeability reduction. Once the bubbles become isolated by bubble collapse, gas pressure will return to magmastatic values, driving volatile resorption back into the melt. CO2/H2O enrichment can occur if the gas added, which comes from deeper magma, has a higher CO2/H2O content than the gas lost by flow upwards. To assess the feasibility of increasing CO2/H2O ratios by this process, requires comparison of three timescales: 1) gas escape, 2) bubble collapse by viscous flow of melt and 3) diffusion of volatiles through melt into bubbles. As gas escapes, the gas pressure gradient decreases and gas flux reduces. In contrast, the pressure difference driving volatile diffusion into the bubbles, and bubble collapse (pressure of melt - pressure inside bubble) will initially be small, but will increase as gas escapes.

Rust, A.; Blundy, J.; Cashman, K.

2007-12-01

338

Thermal enrichment and speciation of copper in rice husk ashes.  

PubMed

Copper(II) was considerably enriched in the residual ash via thermal treatment of copper-sorbed rice husk at 700-1100°C for 2h, and the copper speciation was quantitatively determined with X-ray absorption spectroscopy. After the thermal process, the resulting ash only represents by weight 18.7-26.4% of the pre-heated samples. Copper content in the ashes is >7% which is far above the required minimum copper content in copper ores for the copper smelting sector, 0.5%. Crystalline SiO(2) is observed only in the ash generated at 1100°C, with more copper in this ash being available for leaching in acidic solution. It is suggested that this is due to the considerable dissimilarity in crystalline structure between copper compounds and crystalline SiO(2). No chemical reaction between copper and SiO(2) is observed in any ash. In fact, we suggest that the SiO(2) crystalline phase repels copper during the thermal process; this would make it easy to extract copper from the ashes. For copper speciation in the ashes, CuO merely represents 0-12% of the total copper, while Cu(2)O and Cu(0) represent 34-42% and 46-63%, respectively. The lower copper oxidation state would be beneficial for the copper smelting process due to less usage of coke. PMID:20869164

Wei, Yu-Ling; Hu, Ming-Jan; Peng, Yen-Hsun

2010-12-15

339

New Measures to Safeguard Gas Centrifuge Enrichment Plants  

SciTech Connect

As Gas Centrifuge Enrichment Plants (GCEPs) increase in separative work unit (SWU) capacity, the current International Atomic Energy Agency (IAEA) model safeguards approach needs to be strengthened. New measures to increase the effectiveness of the safeguards approach are being investigated that will be mutually beneficial to the facility operators and the IAEA. One of the key concepts being studied for application at future GCEPs is embracing joint use equipment for process monitoring of load cells at feed and withdrawal (F/W) stations. A mock F/W system was built at Oak Ridge National Laboratory (ORNL) to generate and collect F/W data from an analogous system. The ORNL system has been used to collect data representing several realistic normal process and off-normal (including diversion) scenarios. Emphasis is placed on the novelty of the analysis of data from the sensors as well as the ability to build information out of raw data, which facilitates a more effective and efficient verification process. This paper will provide a progress report on recent accomplishments and next steps.

Whitaker, Jr., James [ORNL; Garner, James R [ORNL; Whitaker, Michael [ORNL; Lockwood, Dunbar [U.S. Department of Energy, NNSA; Gilligan, Kimberly V [ORNL; Younkin, James R [ORNL; Hooper, David A [ORNL; Henkel, James J [ORNL; Krichinsky, Alan M [ORNL

2011-01-01

340

Effect of phase behavior on bypassing in enriched gas floods  

SciTech Connect

Enriched gas floods incorporate a complex interaction of heterogeneity, fingering, multiphase flow, and phase behavior. Experiments and simulations indicate that the optimum solvent enrichment in high-viscosity-ratio secondary gas floods can be below minimum miscibility enrichment (MME). The compositional path and resulting mobility profile in multidimensional multiple-contact miscible (MCM) or immiscible floods are different from their 1D counterparts for high-viscosity-ratio floods in heterogeneous media.

Burger, J.E.; Bhogeswara, R.; Mohanty, K.K. (Univ. of Houston, TX (United States))

1994-05-01

341

The Effect of Cyanobacterial Biomass Enrichment by Centrifugation and GF/C Filtration on Subsequent Microcystin Measurement.  

PubMed

Microcystins are cyclic peptides produced by multiple cyanobacterial genera. After accumulation in the liver of animals they inhibit eukaryotic serine/threonine protein phosphatases, causing liver disease or death. Accurate detection/quantification of microcystins is essential to ensure safe water resources and to enable research on this toxin. Previous methodological comparisons have focused on detection and extraction techniques, but have not investigated the commonly used biomass enrichment steps. These enrichment steps could modulate toxin production as recent studies have demonstrated that high cyanobacterial cell densities cause increased microcystin levels. In this study, three microcystin-producing strains were processed using no cell enrichment steps (by direct freezing at three temperatures) and with biomass enrichment (by centrifugation or GF/C filtration). After extraction, microcystins were analyzed using liquid chromatography-tandem mass spectrometry. All processing methods tested, except GF/C filtration, resulted in comparable microcystin quotas for all strains. The low yields observed for the filtration samples were caused by adsorption of arginine-containing microcystins to the GF/C filters. Whilst biomass enrichment did not affect microcystin metabolism over the time-frame of normal sample processing, problems associated with GF/C filtration were identified. The most widely applicable processing method was direct freezing of samples as it could be utilized in both field and laboratory environments. PMID:25763766

Rogers, Shelley; Puddick, Jonathan; Wood, Susanna A; Dietrich, Daniel R; Hamilton, David P; Prinsep, Michele R

2015-01-01

342

Mineralization of Trichloroethylene by Heterotrophic Enrichment Cultures  

PubMed Central

Microbial consortia capable of aerobically degrading more than 99% of exogenous trichloroethylene (TCE) (50 mg/liter) were collected from TCE-contaminated subsurface sediments and grown in enrichment cultures. TCE at concentrations greater than 300 mg/liter was not degraded, nor was TCE used by the consortia as a sole energy source. Energy sources which permitted growth included tryptone-yeast extract, methanol, methane, and propane. The optimum temperature range for growth and subsequent TCE consumption was 22 to 37°C, and the pH optimum was 7.0 to 8.1. Utilization of TCE occurred only after apparent microbial growth had ceased. The major end products recovered were hydrochloric acid and carbon dioxide. Minor products included dichloroethylene, vinylidine chloride, and, possibly, chloroform. PMID:16347682

Fliermans, C. B.; Phelps, T. J.; Ringelberg, D.; Mikell, A. T.; White, D. C.

1988-01-01

343

Ultraheavy Element Enrichment in Impulsive Solar Flares  

NASA Astrophysics Data System (ADS)

Particle acceleration by cascading Alfvén wave turbulence was suggested as being responsible for energetic particle populations in 3He-rich solar flares. In particular, it was noted that the damping of the turbulence by the tail of the particle distribution in rigidity naturally leads to the dramatic enhancement of a pre-accelerated species—as 3He is posited to be—and superheavy elements. The subsequent detection of large enrichment of ultraheavies, relative to iron, has apparently confirmed this prediction, lending support to the original idea. It is shown here that this picture could be somewhat sharpened by progress in understanding the three-dimensional geometrical details of cascading Alfvén turbulence. The mechanism may be relevant in other astrophysical environments where the source of turbulence is nonmagnetic, such as clusters of galaxies.

Eichler, David

2014-10-01

344

University of Cambridge : Mathematics Enrichment (nrich)  

NSDL National Science Digital Library

University of Cambridge offers this website, Mathematics Enrichment (nrich), with problems, games and articles on mathematics for students ages 5 to 19. The problems are organized by Tiers (1 to 3) and follow the UK education system, but a guide for international educators is given in the Help section. Each problem includes a question, related resources, pictures or diagrams, a form for students to submit their solution, hints for students having difficulty, and notes for parents and teachers. The website is updated monthly and offers a weekly problem. This months theme is the mathematics of making journeys, with the path of the Olympic Torch as an intriguing lead-in to the topic. Registered users can pose questions and post messages in the discussion forum, both of which are also viewable by non-registered viewers. Registration is simple and does not cost anything.

2007-12-12

345

Uranium enrichment decontamination and decommissioning fund  

SciTech Connect

One of the most challenging issues facing the Department of Energy`s Office of Environmental Management is the cleanup of the three gaseous diffusion plants. In October 1992, Congress passed the Energy Policy Act of 1992 and established the Uranium Enrichment Decontamination and Decommissioning Fund to accomplish this task. This mission is being undertaken in an environmentally and financially responsible way by: devising cost-effective technical solutions; producing realistic life-cycle cost estimates, based on practical assumptions and thorough analysis; generating coherent long-term plans which are based on risk assessments, land use, and input from stakeholders; and, showing near-term progress in the cleanup of the gaseous diffusion facilities at Oak Ridge.

NONE

1994-12-31

346

Effects of nutrient enrichment on mangrove leaf litter decomposition.  

PubMed

Nutrient enrichment of mangroves, a common phenomenon along densely populated coastlines, may negatively affect mangrove ecosystems by modifying internal carbon and nutrient cycling. The decomposition of litter exerts a strong influence on these processes and is potentially modified by eutrophication. This study describes effects of N and P enrichment on litter decomposition rate and mineralisation/immobilisation patterns. By making use of reciprocal litter transplantation experiments among fertiliser treatments, it was tested if nutrient addition primarily acts on the primary producers (i.e. changes in litter quantity and quality) or on the microbial decomposers (i.e. changes in nutrient limitation for decomposition). Measurements were done in two mangrove forests where primary production was either limited by N or by P, which had been subject to at least 5 years of experimental N and P fertilisation. Results of this study indicated that decomposers were always N-limited regardless of the limitation of the primary producers. This leads to a differential nutrient limitation between decomposers and primary producers in sites where mangrove production was P-limited. In these sites, fertilisation with P caused litter quality to change, resulting in a higher decomposition rate. This study shows that direct effects of fertilisation on decomposition through an effect on decomposer nutrient availability might be non-significant, while the indirect effects through modifying litter quality might be quite substantial in mangroves. Our results show no indication that eutrophication increases decomposition without stimulating primary production. Therefore we do not expect a decline in carbon sequestration as a result of eutrophication of mangrove ecosystems. PMID:25497680

Keuskamp, Joost A; Hefting, Mariet M; Dingemans, Bas J J; Verhoeven, Jos T A; Feller, Ilka C

2015-03-01

347

The First Supernova Explosions: Energetics, Feedback, and Chemical Enrichment  

E-print Network

We perform three-dimensional smoothed particle hydrodynamics simulations in a realistic cosmological setting to investigate the expansion, feedback, and chemical enrichment properties of a 200 M_sun pair-instability supernova in the high-redshift universe. We find that the SN remnant propagates for a Hubble time at z = 20 to a final mass-weighted mean shock radius of 2.5 kpc (proper), roughly half the size of the HII region, and in this process sweeps up a total gas mass of 2.5*10^5 M_sun. The morphology of the shock becomes highly anisotropic once it leaves the host halo and encounters filaments and neighboring minihalos, while the bulk of the shock propagates into the voids of the intergalactic medium. The SN entirely disrupts the host halo and terminates further star formation for at least 200 Myr, while in our specific case it exerts positive mechanical feedback on neighboring minihalos by shock-compressing their cores. In contrast, we do not observe secondary star formation in the dense shell via gravitational fragmentation, due to the previous photoheating by the progenitor star. We find that cooling by metal lines is unimportant for the entire evolution of the SN remnant, while the metal-enriched, interior bubble expands adiabatically into the cavities created by the shock, and ultimately into the voids with a maximum extent similar to the final mass-weighted mean shock radius. Finally, we conclude that dark matter halos of at least M_vir > 10^8 M_sun must be assembled to recollect all components of the swept-up gas.

Thomas H. Greif; Jarrett L. Johnson; Volker Bromm; Ralf S. Klessen

2009-10-20

348

Assessment for Effective Intervention: Enrichment Science Academic Program  

NASA Astrophysics Data System (ADS)

Israel suffers from a growing problem of socio-economic gaps between those who live in the center of the country and residents of outlying areas. As a result, there is a low level of accessibility to higher education among the peripheral population. The goal of the Sidney Warren Science Education Center for Youth at Tel-Hai College is to strengthen the potential of middle and high school students and encourage them to pursue higher education, with an emphasis on majoring in science and technology. This study investigated the implementation and evaluation of the enrichment science academic program, as an example of informal learning environment, with an emphasis on physics studies. About 500 students conducted feedback survey after participating in science activities in four domains: biology, chemistry, physics, and computer science. Results indicated high level of satisfaction among the students. No differences were found with respect to gender excluding in physics with a positive attitudes advantage among boys. In order to get a deeper understanding of this finding, about 70 additional students conducted special questionnaires, both 1 week before the physics enrichment day and at the end of that day. Questionnaires were intended to assess both their attitudes toward physics and their knowledge and conceptions of the physical concept "pressure." We found that the activity moderately improved boys' attitudes toward physics, but that girls displayed decreased interest in and lower self-efficacy toward physics. Research results were used to the improvement of the instructional design of the physics activity demonstrating internal evaluation process for effective intervention.

Sasson, Irit; Cohen, Donita

2012-11-01

349

Environmental enrichment does not impact on tumor growth in mice  

PubMed Central

The effect of environmental enrichment (EE) on a variety of physiologic and disease processes has been studied in laboratory mice. During EE, a large group of mice are housed in larger cages than the standard cage and are given toys and equipment, enabling more social contact, and providing a greater surface area per mouse, and a more stimulating environment. Studies have been performed into the effect of EE on neurogenesis, brain injury, cognitive capacity, memory, learning, neuronal pathways, diseases such as Alzheimer’s, anxiety, social defeat, emotionality, depression, drug addiction, alopecia, and stereotypies. In the cancer field, three papers have reported effects on mice injected with tumors and housed in enriched environments compared with those housed in standard conditions. One paper reported a significant decrease in tumor growth in mice in EE housing. We attempted to replicate this finding in our animal facility, because the implications of repeating this finding would have profound implications for how we house all our mice in our studies on cancer. We were unable to reproduce the results in the paper in which B16F10 subcutaneous tumors of mice housed in EE conditions were smaller than those of mice housed in standard conditions. The differences in results could have been due to the different growth rate of the B16F10 cultures from the different laboratories, the microbiota of the mice housed in the two animal facilities, variations in noise and handling between the two facilities, food composition, the chemical composition of the cages or the detergents used for cleaning, or a variety of other reasons. EE alone does not appear to consistently result in decreased tumor growth, but other factors would appear to be able to counteract or inhibit the effects of EE on cancer progression. PMID:24555065

Kershaw, Michael H

2013-01-01

350

Enrichment of chemical libraries docked to protein conformational ensembles and application to aldehyde dehydrogenase 2.  

PubMed

Molecular recognition is a complex process that involves a large ensemble of structures of the receptor and ligand. Yet, most structure-based virtual screening is carried out on a single structure typically from X-ray crystallography. Explicit-solvent molecular dynamics (MD) simulations offer an opportunity to sample multiple conformational states of a protein. Here we evaluate our recently developed scoring method SVMSP in its ability to enrich chemical libraries docked to MD structures of seven proteins from the Directory of Useful Decoys (DUD). SVMSP is a target-specific rescoring method that combines machine learning with statistical potentials. We find that enrichment power as measured by the area under the ROC curve (ROC-AUC) is not affected by increasing the number of MD structures. Among individual MD snapshots, many exhibited enrichment that was significantly better than the crystal structure, but no correlation between enrichment and structural deviation from crystal structure was found. We followed an innovative approach by training SVMSP scoring models using MD structures (SVMSPMD). The resulting models were applied to two difficult cases (p38 and CDK2) for which enrichment was not better than random. We found remarkable increase in enrichment power, particularly for p38, where the ROC-AUC increased by 0.30 to 0.85. Finally, we explored approaches for a priori identification of MD snapshots with high enrichment power from an MD simulation in the absence of active compounds. We found that the use of randomly selected compounds docked to the target of interest using SVMSP led to notable enrichment for EGFR and Src MD snapshots. SVMSP rescoring of protein-compound MD structures was applied for the search of small-molecule inhibitors of the mitochondrial enzyme aldehyde dehydrogenase 2 (ALDH2). Rank-ordering of a commercial library of 50?000 compounds docked to MD structures of ALDH2 led to five small-molecule inhibitors. Four compounds had IC50s below 5 ?M. These compounds serve as leads for the design and synthesis of more potent and selective ALDH2 inhibitors. PMID:24856086

Wang, Bo; Buchman, Cameron D; Li, Liwei; Hurley, Thomas D; Meroueh, Samy O

2014-07-28

351

A new method to track seed dispersal and recruitment using 15N isotope enrichment.  

PubMed

Seed dispersal has a powerful influence on population dynamics, genetic structuring, evolutionary rates, and community ecology. Yet, patterns of seed dispersal are difficult to measure due to methodological shortcomings in tracking dispersed seeds from sources of interest. Here we introduce a new method to track seed dispersal: stable isotope enrichment. It consists of leaf-feeding plants with sprays of 15N-urea during the flowering stage such that seeds developed after applications are isotopically enriched. We conducted a greenhouse experiment with Solanum americanum and two field experiments with wild Capsicum annuum in southern Arizona, USA, to field-validate the method. First, we show that plants sprayed with 15N-urea reliably produce isotopically enriched progeny, and that delta 15N (i.e., the isotopic ratio) of seeds and seedlings is a linear function of the 15N-urea concentration sprayed on mothers. We demonstrate that three urea dosages can be used to distinctly enrich plants and unambiguously differentiate their offspring after seeds are dispersed by birds. We found that, with high urea dosages, the resulting delta 15N values in seedlings are 10(3) - 10(4) times higher than the delta 15N values of normal plants. This feature allows tracking not only where seeds arrive, but in locations where seeds germinate and recruit, because delta 15N enrichment is detectable in seedlings that have increased in mass by at least two orders of magnitude before fading to normal delta 15N values. Last, we tested a mixing model to analyze seed samples in bulk. We used the delta 15N values of batches (i.e., combined seedlings or seeds captured in seed traps) to estimate the number of enriched seeds coming from isotopically enriched plants in the field. We confirm that isotope enrichment, combined with batch-sampling, is a cheap, reliable, and user-friendly method for bulk-processing seeds and is thus excellent for the detection of rare dispersal events. This method could further the study of dispersal biology, including the elusive, but critically important, estimation of long-distance seed dispersal. PMID:20120818

Carlo, Tomás A; Tewksbury, Joshua J; Martínez Del Río, Carlos

2009-12-01

352

Photoablative dilution with pre-enrichment for the clonal isolation of rare cancer cells  

NASA Astrophysics Data System (ADS)

The clonal isolation of rare cells, especially cancer and stem cells, in a population is important to cell biology. We have demonstrated that the Laser-Enabled Analysis and Processing (LEAP, Cyntellect Inc., San Diego, CA) instrument can be used to efficiently produce clones by photoablative dilution. The LEAP instrument performs automated fluorescence imaging and real-time image analysis to classify cells. The instrument also features a pulsed laser that gives it the ability to purify a sample by eliminating unwanted cells via laser ablation or UV-induced apoptosis. In photoablative dilution, rare cells are deposited into a multiwell plate at 10 cells per well. Then one cell is chosen to clone, and the other cells present in the well are eliminated by laser ablation. We have successfully used LEAP to produce single cell clones in 95% of wells (originally containing 5+/-2.1 cells/well). While photoablative dilution is a very effective way of producing clonal cultures, it has a fundamental limitation in the low number of cells that can be processed. This can be overcome by performing a pre-enrichment to increase the frequency of the rare cells to be cloned. Another enrichment strategy is flow cytometry based cell sorting. Flow sorting can provide greater than 104 fold enrichment and cells can be sorted directly into a multiwell plate. With pre-enrichment, photoablative dilution can be used to clonally isolate rare cells. This is especially important in cases where the total number of potentially rare cells recovered by first stage enrichment sorting is only 10-200 cells. Such a situation which would normally preclude second pass sorting for purity by the high-throughput first stage cell separation technology.

Zordan, Michael D.; Leary, James F.

2009-02-01

353

Conversion of crude oil to methane by a microbial consortium enriched from oil reservoir production waters  

PubMed Central

The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls), corresponding to the detection of an alkyl succinate synthase encoding gene (assA/masA) in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up to 5.8 ?mol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic vs. sessile) within a subsurface crude oil reservoir. PMID:24829563

Berdugo-Clavijo, Carolina; Gieg, Lisa M.

2014-01-01

354

Influence of Enriched Environment on Viral Encephalitis Outcomes: Behavioral and Neuropathological Changes in Albino Swiss Mice  

PubMed Central

An enriched environment has previously been described as enhancing natural killer cell activity of recognizing and killing virally infected cells. However, the effects of environmental enrichment on behavioral changes in relation to virus clearance and the neuropathology of encephalitis have not been studied in detail. We tested the hypothesis that environmental enrichment leads to less CNS neuroinvasion and/or more rapid viral clearance in association with T cells without neuronal damage. Stereology-based estimates of activated microglia perineuronal nets and neurons in CA3 were correlated with behavioral changes in the Piry rhabdovirus model of encephalitis in the albino Swiss mouse. Two-month-old female mice maintained in impoverished (IE) or enriched environments (EE) for 3 months were behaviorally tested. After the tests, an equal volume of Piry virus (IEPy, EEPy)-infected or normal brain homogenates were nasally instilled. Eight days post-instillation (dpi), when behavioral changes became apparent, brains were fixed and processed to detect viral antigens, activated microglia, perineuronal nets, and T lymphocytes by immuno- or histochemical reactions. At 20 or 40 dpi, the remaining animals were behaviorally tested and processed for the same markers. In IEPy mice, burrowing activity decreased and recovered earlier (8–10 dpi) than open field (20–40 dpi) but remained unaltered in the EEPy group. EEPy mice presented higher T-cell infiltration, less CNS cell infection by the virus and/or faster virus clearance, less microgliosis, and less damage to the extracellular matrix than IEPy. In both EEPy and IEPy animals, CA3 neuronal number remained unaltered. The results suggest that an enriched environment promotes a more effective immune response to clear CNS virus and not at the cost of CNS damage. PMID:21264301

Bento-Torres, João; Trévia, Nonata; de Almeida Lins, Nara Alves; Passos, Aline; Santos, Zaire; Diniz, José Antonio Picanço; da Costa Vasconcelos, Pedro Fernando; Cunningham, Colm; Perry, Victor Hugh; Picanço Diniz, Cristovam Wanderley

2011-01-01

355

Conversion of crude oil to methane by a microbial consortium enriched from oil reservoir production waters.  

PubMed

The methanogenic biodegradation of crude oil is an important process occurring in petroleum reservoirs and other oil-containing environments such as contaminated aquifers. In this process, syntrophic bacteria degrade hydrocarbon substrates to products such as acetate, and/or H2 and CO2 that are then used by methanogens to produce methane in a thermodynamically dependent manner. We enriched a methanogenic crude oil-degrading consortium from production waters sampled from a low temperature heavy oil reservoir. Alkylsuccinates indicative of fumarate addition to C5 and C6 n-alkanes were identified in the culture (above levels found in controls), corresponding to the detection of an alkyl succinate synthase encoding gene (assA/masA) in the culture. In addition, the enrichment culture was tested for its ability to produce methane from residual oil in a sandstone-packed column system simulating a mature field. Methane production rates of up to 5.8 ?mol CH4/g of oil/day were measured in the column system. Amounts of produced methane were in relatively good agreement with hydrocarbon loss showing depletion of more than 50% of saturate and aromatic hydrocarbons. Microbial community analysis revealed that the enrichment culture was dominated by members of the genus Smithella, Methanosaeta, and Methanoculleus. However, a shift in microbial community occurred following incubation of the enrichment in the sandstone columns. Here, Methanobacterium sp. were most abundant, as were bacterial members of the genus Pseudomonas and other known biofilm forming organisms. Our findings show that microorganisms enriched from petroleum reservoir waters can bioconvert crude oil components to methane both planktonically and in sandstone-packed columns as test systems. Further, the results suggest that different organisms may contribute to oil biodegradation within different phases (e.g., planktonic vs. sessile) within a subsurface crude oil reservoir. PMID:24829563

Berdugo-Clavijo, Carolina; Gieg, Lisa M

2014-01-01

356

Arsenic Enrichment in Surface Water and Soil in Tibetan Plateau  

NASA Astrophysics Data System (ADS)

Corresponding author: yan.zheng@qc.cuny.edu The average soil arsenic concentration was reported to be 18.7 mg/kg based on a survey of 205 samples in Tibet. This is considerably higher than the commonly cited crustal background value of 10 mg/kg of As for soil, and is unlikely due to anthropogenic pollution. To investigate the origin of this geochemical anomaly in soil arsenic, water (n=80), stream sediment (n=69), soil (n=79), rock (n=58) samples were collected from the Yarlung Zangbo (upstream of Brahmaputra) River drainage and Shiquan (upstream of Indus) River drainage basins in June of 2008. Arsenic enrichment is pronounced in the Shiquan River drainage. The average arsenic concentration in soil, stream sediment and stream water is 34±23 mg/kg (n=33, range <12-84 mg/kg), 35± mg/kg (n=37, range <14-197 mg/kg) and 5±69 g/L (n=39, range 2-252 g/L), respectively. In the Yarlung Zangbo River drainage, the average arsenic concentration in soil, stream sediment and stream water is 28±35 mg/kg (n=23, range <12-152 mg/kg), 22±7 mg/kg (n=28, range <14-44 mg/kg) and 11±16 g/L (n=30, range 2 -83 g/L), respectively. The average concentration of arsenic in upstream water of Yarlung Zangbo River is 38±28 g/L (n=5), and is much higher than the value of 5±3 g/L (n=23) downstream. The high background concentration of arsenic in soil of this area may be associated to the broad distribution of ophiolite melange and meta-sedimentary sequences containing shale, phyllite and schist that may be rich in arsenic. However, the maximum concentration of arsenic in rock is only 35±6mg/kg in metamorphic breccia. About 91% of the rock samples are lower than the limit of detection of XRF (15 mg/kg). Thus, it is more likely that soil As enrichment result from the weathering process of rocks under cold and arid plateau conditions. Whether this soil As anomaly in Tibetan Plateau affects the down stream flood plain sedimentary As content or not requires further study. Other types water sampled also show As enrichment. Two hot spring waters contain 5985 g/L and 3842 g/L arsenic. A dug well (about 2m depth) is found to contain 195 g/L As. The average arsenic concentration of salt lake water is 1947±3619 g/L (n=8, range 40-10626 g/L ), but a fresh water lake has only 21 g/L arsenic. Arsenic enrichment in water samples from the Shiquan River and the upstream of the Yarlung Zangbo River is not only associated with higher concentrations of arsenic in soils and rocks but also associated to the salt lake and hot spring in these drainages.

Li, S.; Wang, M.; Zheng, B.; Zheng, Y.

2008-12-01

357

The use of isotopically enriched tin tracers to follow the transformation of organotin compounds in landfill leachate.  

PubMed

Landfill leachates are an important pool of organotin compounds (OTCs). Several studies have been performed on the occurrence of OTCs in landfill leachates, but only a few of them report degradation and biomethylation processes by bacteria. In the present study transformation of OTCs in landfill leachate was investigated under simulated landfill conditions over a time span of six months. The degradation and biomethylation processes of OTCs were followed by the use of isotopically enriched tin tracers, namely (117)Sn-enriched tributyltin (TBT), (119)Sn-enriched dibutyltin (DBT), (117)Sn-enriched SnCl2, (117)Sn-enriched SnCl4 and a (119)Sn-enriched butyltin mix containing TBT, DBT and monobutyltin (MBT). Transformation of OTCs in spiked leachates was followed at m/z of the enriched spikes and at m/z 120, which allowed simultaneous observation of the transformation of OTCs in the leachate itself and of the added spike. In parallel, these processes were also monitored in a non-spiked leachate sample at m/z 120. Quantification of OTCs was performed by gas chromatography - inductively coupled plasma mass spectrometry (GC-ICP-MS). To discriminate the biotic and abiotic transformations of OTCs and inorganic tin species, sterilization of leachate was also performed and data compared to non-sterilized samples. During the course of the experiment the microbial degradation of TBT was clearly manifested in Sn-enriched spiked leachate samples, while abiotic pathway of degradation was observed for DBT. Biomethylation process was also observed in the leachate spiked with Sn-enriched Sn(2+) or Sn(4+), in concentrations close to those found for total tin in landfill leachates. Monomethyltin (MMeT) was formed first. Stepwise alkylation resulted in dimethyltin (DMeT) and trimethyltin (TMeT) species formation. Hydrolysis of Sn(2+) and Sn(4+) species was found to be a limiting factor which controlled the extent of methyltin formation. The results of the present investigation importantly contribute to a better understanding of the processes that OTCs undergo in leachates, and provide useful information to managers of landfills in taking measures necessary to prevent the release of toxic methyltin species to the nearby environment. PMID:24530549

Peeters, Kelly; Zuliani, Tea; Š?an?ar, Janez; Mila?i?, Radmila

2014-04-15

358

Chemical Self-Enrichment of HII Regions by the Wolf-Rayet Phase of an 85 Msun star  

E-print Network

It is clear from stellar evolution and from observations of WR stars that massive stars are releasing metal-enriched gas through their stellar winds in the Wolf-Rayet phase. Although HII region spectra serve as diagnostics to determine the present-day chemical composition of the interstellar medium, it is far from being understood to what extent the HII gas is already contaminated by chemically processed stellar wind. Therefore, we analyzed our models of radiative and wind bubbles of an isolated 85 Msun star with solar metallicity (Kr\\"oger et al. 2006) with respect to the chemical enrichment of the circumstellar HII region. Plausibly, the hot stellar wind bubble (SWB) is enriched with 14N during the WN phase and even much higher with 12C and 16O during the WC phase of the star. During the short period that the 85 Msun star spends in the WC stage enriched SWB material mixes with warm HII gas of solar abundances and thus enhances the metallicity in the HII region. However, at the end of the stellar lifetime the mass ratios of the traced elements N and O in the warm ionized gas are insignificantly higher than solar, whereas an enrichment of 22 % above solar is found for C. Important issues from the presented study comprise a steeper radial gradient of C than O and a decreasing effect of self-enrichment for metal-poor galaxies.

Danica Kröger; Gerhard Hensler; Tim Freyer

2006-03-08

359

Nucleosynthesis in Stars and the Chemical Enrichment of Galaxies  

NASA Astrophysics Data System (ADS)

After the Big Bang, production of heavy elements in the early Universe takes place starting from the formation of the first stars, their evolution, and explosion. The first supernova explosions have strong dynamical, thermal, and chemical feedback on the formation of subsequent stars and evolution of galaxies. However, the nature of the Universe's first stars and supernova explosions has not been well clarified. The signature of the nucleosynthesis yields of the first stars can be seen in the elemental abundance patterns observed in extremely metal-poor stars. Interestingly, those patterns show some peculiarities relative to the solar abundance pattern, which should provide important clues to understanding the nature of early generations of stars. We thus review the recent results of the nucleosynthesis yields of mainly massive stars for a wide range of stellar masses, metallicities, and explosion energies. We also provide yields tables and examine how those yields are affected by some hydrodynamical effects during supernova explosions, namely, explosion energies from those of hypernovae to faint supernovae, mixing and fallback of processed materials, asphericity, etc. Those parameters in the supernova nucleosynthesis models are constrained from observational data of supernovae and metal-poor stars. Nucleosynthesis yields are then applied to the chemical evolution model of our Galaxy and other types of galaxies to discuss how the chemical enrichment process occurred during evolution.

Nomoto, Ken'ichi; Kobayashi, Chiaki; Tominaga, Nozomu

2013-08-01

360

Discontinuous pH gradient-mediated separation of TiO2-enriched phosphopeptides  

PubMed Central

Global profiling of phosphoproteomes has proven a great challenge due to the relatively low stoichiometry of protein phosphorylation and poor ionization efficiency in mass spectrometers. Effective, physiologically-relevant, phosphoproteome research relies on the efficient phosphopeptide enrichment from complex samples. Immobilized metal affinity chromatography and titanium dioxide chromatography (TOC) can greatly assist selective phosphopeptide enrichment. However, the complexity of resultant enriched samples is often still high, suggesting that further separation of enriched phosphopeptides is required. We have developed a pH-gradient elution technique for enhanced phosphopeptide identification in conjunction with TOC. Using this process, we have demonstrated its superiority to the traditional ‘one-pot’ strategies for differential protein identification. Our technique generated a highly specific separation of phosphopeptides by an applied pH-gradient between 9.2 and 11.3. The most efficient elution range for high-resolution phosphopeptide separation was between pH 9.2 and 9.4. High-resolution separation of multiply-phosphorylated peptides was primarily achieved using elution ranges > pH 9.4. Investigation of phosphopeptide sequences identified in each pH fraction indicated that phosphopeptides with phosphorylated residues proximal to acidic residues, including glutamic acid, aspartic acid, and other phosphorylated residues, were preferentially eluted at higher pH values. PMID:20946866

Park, Sung-Soo; Maudsley, Stuart

2010-01-01

361

HIGHLY ENRICHED URANIUM BLEND DOWN PROGRAM AT THE SAVANNAH RIVER SITE PRESENT AND FUTURE  

SciTech Connect

The Department of Energy (DOE) and Tennessee Valley Authority (TVA) entered into an Interagency Agreement to transfer approximately 40 metric tons of highly enriched uranium (HEU) to TVA for conversion to fuel for the Browns Ferry Nuclear Power Plant. Savannah River Site (SRS) inventories included a significant amount of this material, which resulted from processing spent fuel and surplus materials. The HEU is blended with natural uranium (NU) to low enriched uranium (LEU) with a 4.95% 235U isotopic content and shipped as solution to the TVA vendor. The HEU Blend Down Project provided the upgrades needed to achieve the product throughput and purity required and provided loading facilities. The first blending to low enriched uranium (LEU) took place in March 2003 with the initial shipment to the TVA vendor in July 2003. The SRS Shipments have continued on a regular schedule without any major issues for the past 5 years and are due to complete in September 2008. The HEU Blend program is now looking to continue its success by dispositioning an additional approximately 21 MTU of HEU material as part of the SRS Enriched Uranium Disposition Project.

Magoulas, V; Charles Goergen, C; Ronald Oprea, R

2008-06-05

362

ENRICHED STABLE ISOTOPE TARGET PREPARATION AT THE OAK RIDGE NATIONAL LABORATORY  

SciTech Connect

Since the 1960s the Department of Energy (DOE) Isotope Program, through the Isotope Development Group at the Oak Ridge National Laboratory, has been developing and supplying, among other things, enriched stable isotope targets for nuclear research around the world. This group also maintains and distributes the DOE inventory of enriched stable isotopes. Chemical and pyrochemical techniques are used to prepare enriched stable isotopes from this inventory in the desired chemical form. Metallurgical, ceramic, or vacuum processing methods are then used to prepare the isotopes in a wide range of physical forms from thin films, foils, and coatings to large fabricated shapes to meet the needs of experimenters. Significant characterization capabilities are also available to assist in the preparation and evaluation of these custom materials. This work is part of the DOE Isotope Program, which recently transferred to the Office of Nuclear Physics, DOE Office of Science, resulting in a stronger emphasis on enabling R&D. This presentation will focus on the custom preparation of enriched stable isotope targets and other research materials.

Aaron, W Scott [ORNL] [ORNL; Zevenbergen, Lee [ORNL] [ORNL

2013-01-01

363

Production, characterization and operation of Ge enriched BEGe detectors in GERDA  

NASA Astrophysics Data System (ADS)

The GERmanium Detector Array ( Gerda) at the Gran Sasso Underground Laboratory (LNGS) searches for the neutrinoless double beta decay () of Ge. Germanium detectors made of material with an enriched Ge fraction act simultaneously as sources and detectors for this decay. During Phase I of theexperiment mainly refurbished semi-coaxial Ge detectors from former experiments were used. For the upcoming Phase II, 30 new Ge enriched detectors of broad energy germanium (BEGe)-type were produced. A subgroup of these detectors has already been deployed in Gerda during Phase I. The present paper reviews the complete production chain of these BEGe detectors including isotopic enrichment, purification, crystal growth and diode production. The efforts in optimizing the mass yield and in minimizing the exposure of the Ge enriched germanium to cosmic radiation during processing are described. Furthermore, characterization measurements in vacuum cryostats of the first subgroup of seven BEGe detectors and their long-term behavior in liquid argon are discussed. The detector performance fulfills the requirements needed for the physics goals of Gerda Phase II.

Agostini, M.; Allardt, M.; Andreotti, E.; Bakalyarov, A. M.; Balata, M.; Barabanov, I.; Barros, N.; Baudis, L.; Bauer, C.; Becerici-Schmidt, N.; Bellotti, E.; Belogurov, S.; Belyaev, S. T.; Benato, G.; Bettini, A.; Bezrukov, L.; Bode, T.; Borowicz, D.; Brudanin, V.; Brugnera, R.; Budjáš, D.; Caldwell, A.; Cattadori, C.; Chernogorov, A.; D'Andrea, V.; Demidova, E. V.; Domula, A.; Egorov, V.; Falkenstein, R.; Freund, K.; Frodyma, N.; Gangapshev, A.; Garfagnini, A.; Gotti, C.; Grabmayr, P.; Gurentsov, V.; Gusev, K.; Hegai, A.; Heisel, M.; Hemmer, S.; Heusser, G.; Hofmann, W.; Hult, M.; Inzhechik, L. V.; Ioannucci, L.; Janicskó Csáthy, J.; Jochum, J.; Junker, M.; Kazalov, V.; Kihm, T.; Kirpichnikov, I. V.; Kirsch, A.; Klimenko, A.; Knöpfle, K. T.; Kochetov, O.; Kornoukhov, V. N.; Kuzminov, V. V.; Laubenstein, M.; Lazzaro, A.; Lebedev, V. I.; Lehnert, B.; Liao, H. Y.; Lindner, M.; Lippi, I.; Lubashevskiy, A.; Lubsandorzhiev, B.; Lutter, G.; Macolino, C.; Majorovits, B.; Maneschg, W.; Misiaszek, M.; Nemchenok, I.; Nisi, S.; O'Shaughnessy, C.; Palioselitis, D.; Pandola, L.; Pelczar, K.; Pessina, G.; Pullia, A.; Riboldi, S.; Rumyantseva, N.; Sada, C.; Salathe, M.; Schmitt, C.; Schreiner, J.; Schulz, O.; Schütz, A.-K.; Schwingenheuer, B.; Schönert, S.; Shevchik, E.; Shirchenko, M.; Simgen, H.; Smolnikov, A.; Stanco, L.; Strecker, H.; Ur, C. A.; Vanhoefer, L.; Vasenko, A. A.; von Sturm, K.; Wagner, V.; Walter, M.; Wegmann, A.; Wester, T.; Wilsenach, H.; Wojcik, M.; Yanovich, E.; Zavarise, P.; Zhitnikov, I.; Zhukov, S. V.; Zinatulina, D.; Zuber, K.; Zuzel, G.

2015-02-01

364

Atmospheric mercury emissions from mine wastes and surrounding geologically enriched terrains  

USGS Publications Warehouse

Waste rock and ore associated with Hg, precious and base metal mining, and their surrounding host rocks are typically enriched in mercury relative to natural background concentrations (<0.1 ??g Hg g-1). Mercury fluxes to the atmosphere from mineralized areas can range from background rates (0-15 ng m-2 h-1) to tens of thousands of ng m-2 h-1. Mercury enriched substrate constitutes a long-term source of mercury to the global atmospheric mercury pool. Mercury emissions from substrate are influenced by light, temperature, precipitation, and substrate mercury concentration, and occur during the day and night. Light-enhanced emissions are driven by two processes: desorption of elemental mercury accumulated at the soil:air interface, and photo reduction of mercury containing phases. To determine the need for and effectiveness of regulatory controls on short-lived anthropogenic point sources the contribution of mercury from geologic non-point sources to the atmospheric mercury pool needs to be quantified. The atmospheric mercury contribution from small areas of mining disturbance with relatively high mercury concentrations are, in general, less than that from surrounding large areas of low levels of mercury enrichment. In the arid to semi-arid west-ern United States volatilization is the primary means by which mercury is released from enriched sites.

Gustin, M.S.; Coolbaugh, M.F.; Engle, M.A.; Fitzgerald, B.C.; Keislar, R.E.; Lindberg, S.E.; Nacht, D.M.; Quashnick, J.; Rytuba, J.J.; Sladek, C.; Zhang, H.; Zehner, R.E.

2003-01-01

365

Macrozoobenthic community structure in two Portuguese estuaries: Relationship with organic enrichment and nutrient gradients  

NASA Astrophysics Data System (ADS)

The aim of this work consists in the study of the structural and functional aspects of the macrozoobenthic communities and their relationships with the organic enrichment and nutrient gradients in water and sediment. The study was carried out in two coastal ecosystems under strong anthropogenic pressure: the Sado estuary and the Aveiro Lagoon. Samples were collected at four stations between October 1994 and April 1995. The results obtained allowed us to state that spatial variability, both horizontal and vertical, was higher than the temporal variability. This was due to local hydrodynamism, organic load and granulometric structure of the sediment. Comparing the community structure at the different stations, it was possible to observe the existence of disturbance cases not directly related to organic enrichment gradients. The interpretation of the functional role of the macrozoobenthic communities at the water-sediment interface was based on the trophodynamic group classification. This approach allowed us to state that the sensitivity of different groups to organic enrichment, confirming the role of burrower subsurface-deposit feeders as opportunists associated with organic enrichment and, on the other hand, the influence of certain trophodynamic groups in the nutrient transfer processes, particularly the association between tube-builder omnivores and burrower carnivore and nitrate content in interstitial water.

Mucha, Ana Paula; Costa, Maria Helena

1999-07-01

366

The role of colliding galaxies and tidal dwarf galaxies in the ISM/IGM enrichment  

NASA Astrophysics Data System (ADS)

This review discusses the processes associated with galaxy collisions that contribute to the enrichment of the interstellar and intergalactic medium. Chemical evolution is driven by two main effects: (a) local enrichment of the ISM/IGM following star formation episodes triggered by collisions, occurring in two main modes, (1) a nuclear starburst, which results in superwinds/outflows, with injection of metals up to the intergalactic medium, (2) extended star formation episodes locally enriching up to large distances the surrounding ISM, and even the IGM when occurring within extended tidal tails and in tidal dwarf galaxies (b) radial mixing of the gas, with (1) the funneling of metal-poor gas in the central regions and a dilution of the metals there, (2) the transport of pre-enriched dusty gas towards external regions including tidal structures. The net effect is a flattening of the metallicity gradient of colliding galaxies, which is predicted by numerical simulations and observed in real systems. The last part of the paper addresses and belittles the specific contribution of collisional debris, especially tidal dwarf galaxies, in the pollution of the Universe.

Duc, P.-A.

367

Enrichment of By-Product Materials from Steel Pickling Acid Regeneration Plants (TRP 9942)  

SciTech Connect

A new process for manufacturing an enriched, iron-based product (strontium hexaferrite) in existing steel pickling acid regeneration facilities was evaluated. Process enhancements and equipment additions were made to an existing acid regeneration plant to develop and demonstrate (via pilot scale testing and partial-capacity production trials) the viability of a patented method to produce strontium-based compounds that, when mixed with steel pickling acid and roasted, would result in a strontium hexaferrite powder precursor which could then be subjected to further heat treatment in an atmosphere that promotes rapid, relatively low-temperature formation of discrete strontium hexaferrite magnetic domains yielding an enriched iron-based product, strontium hexaferrite, that can be used in manufacturing hard ferrite magnets.

Lu Swan, Delta Ferrites LLC

2009-09-30

368

Establishing Specifications for Low Enriched Uranium Fuel Operations Conducted Outside the High Flux Isotope Reactor Site  

SciTech Connect

The National Nuclear Security Administration (NNSA) has funded staff at Oak Ridge National Laboratory (ORNL) to study the conversion of the High Flux Isotope Reactor (HFIR) from the current, high enriched uranium fuel to low enriched uranium fuel. The LEU fuel form is a metal alloy that has never been used in HFIR or any HFIR-like reactor. This report provides documentation of a process for the creation of a fuel specification that will meet all applicable regulations and guidelines to which UT-Battelle, LLC (UTB) the operating contractor for ORNL - must adhere. This process will allow UTB to purchase LEU fuel for HFIR and be assured of the quality of the fuel being procured.

Pinkston, Daniel [ORNL; Primm, Trent [ORNL; Renfro, David G [ORNL; Sease, John D [ORNL

2010-10-01

369

Detection of illicit HEU production in gaseous centrifuge enrichment plants using neutron counting techniques on product cylinders  

SciTech Connect

Innovative and novel safeguards approaches are needed for nuclear energy to meet global energy needs without the threat of nuclear weapons proliferation. Part of these efforts will include creating verification techniques that can monitor uranium enrichment facilities for illicit production of highly-enriched uranium (HEU). Passive nondestructive assay (NDA) techniques will be critical in preventing illicit HEU production because NDA offers the possibility of continuous and unattended monitoring capabilities with limited impact on facility operations. Gaseous centrifuge enrichment plants (GCEP) are commonly used to produce low-enriched uranium (LEU) for reactor fuel. In a GCEP, gaseous UF{sub 6} spins at high velocities in centrifuges to separate the molecules containing {sup 238}U from those containing the lighter {sup 235}U. Unfortunately, the process for creating LEU is inherently the same as HEU, creating a proliferation concern. Insuring that GCEPs are producing declared enrichments poses many difficult challenges. In a GCEP, large cascade halls operating thousands of centrifuges work together to enrich the uranium which makes effective monitoring of the cascade hall economically prohibitive and invasive to plant operations. However, the enriched uranium exiting the cascade hall fills product cylinders where the UF{sub 6} gas sublimes and condenses for easier storage and transportation. These product cylinders hold large quantities of enriched uranium, offering a strong signal for NDA measurement. Neutrons have a large penetrability through materials making their use advantageous compared to gamma techniques where the signal is easily attenuated. One proposed technique for detecting HEU production in a GCEP is using neutron coincidence counting at the product cylinder take off stations. This paper discusses findings from Monte Carlo N-Particle eXtended (MCNPX) code simulations that examine the feasibility of such a detector.

Freeman, Corey R [Los Alamos National Laboratory; Geist, William H [Los Alamos National Laboratory

2010-01-01

370

Arts Enrichment and School Readiness for Children at Risk  

ERIC Educational Resources Information Center

Arts enrichment provides varied channels for acquiring school readiness skills and may offer important educational opportunities for students from diverse backgrounds and with diverse needs. Study 1 examined achievement within an arts enrichment preschool that served low-income children. Results indicated that students practiced school readiness…

Brown, Eleanor D.; Benedett, Barbara; Armistead, M. Elizabeth

2010-01-01

371

Research Related to the Schoolwide Enrichment Triad Model.  

ERIC Educational Resources Information Center

This article reviews research on the Schoolwide Enrichment Triad Model, which combines the previously developed Enrichment Triad and Revolving Door Identification Models of gifted education. Research reviewed addresses: model effectiveness, creative productivity, personal and social development, underserved populations, self-efficacy, curricular…

Renzulli, Joseph S.; Reis, Sally M.

1994-01-01

372

Schoolwide Enrichment Model: Challenging All Children to Excel  

ERIC Educational Resources Information Center

This article summarizes how the components of the Schoolwide Enrichment Model were used to dramatically reduce the achievement gap in a school with a high at-risk student population. The theories of enrichment and instructional differentiation replaced an existing remedial paradigm and a strength-based methodology was embraced by the school…

Beecher, Margaret

2010-01-01

373

Lessons Learned from Coordinating a Schoolwide Enrichment Program.  

ERIC Educational Resources Information Center

Eleven suggestions are provided for implementation of the Schoolwide Enrichment Model to meet students' needs for enriched learning opportunities. Suggestions include respect the individual interests and styles of faculty; don't waste time trying to convince everyone; and be careful not to take credit for what others do. (JDD)

Smith, David

1991-01-01

374

Enrichment of nuclear spin isomers of molecules by bichromatic field  

NASA Astrophysics Data System (ADS)

A theoretical model for the enrichment of nuclear spin isomers of molecules by two electromagnetic fields is developed. The fields are resonant with the rotational transitions in the ground electronic and vibrational state of the molecule. Numerical calculations reveal a complicated dependence of the isomer enrichment on the radiation frequencies that consists of three peaks with different shapes, widths and amplitudes.

Chapovsky, P. L.; Wilson-Gordon, A. D.

2015-03-01

375

Responses of C 4 grasses to atmospheric CO 2 enrichment  

Microsoft Academic Search

The growth and photosynethetic responses to atmospheric CO2 enrichment of 4 species of C4 grasses grown at two levels of irradiance were studied. We sought to determine whether CO2 enrichment would yield proportionally greater growth enhancement in the C4 grasses when they were grown at low irradiance than when grown at high irradiance. The species studied were Echinochloa crusgalli, Digitaria

Nasser Sionit; David T. Patterson

1984-01-01

376

ENRICHMENT OF A JET OF VAPOR ENTERING A VACUUM  

Microsoft Academic Search

It is known that in the purification of metals by vacuum distillation, ; the condensate is enriched by oxygen and nitrogen residual gas. The amount of ; enrichment was measured with a new apparatus. Mercury was vaporized and Hg\\/sup ; 203\\/ was used as the residual gas. The surface of the consensate covered with a ; layer of the residual

Burlakov

1957-01-01

377

Reteach and Enrich: How to Make Time for Every Student  

NSDL National Science Digital Library

This 5-minute video from "Schools that Work" introduces a concept of "Reteach and Enrich" that was implemented at Mesquite Elementary School in Tucson, AZ. This teaching strategy changed the culture of their school and drastically improved students understanding of math skills as well as their test scores. Also in this resource is a link to learn more about reteach and enrich.

2011-10-06

378

Enriching Intrusion Alerts Through Multi-Host Causality  

Microsoft Academic Search

Current intrusion detection systems point out suspicious states or events but do not show how the suspicious state or events relate to other states or events in the system. We show how to enrich an IDS alert with information about how those alerts causally lead to or result from other events in the system. By enriching IDS alerts with this

Samuel T. King; Zhuoqing Morley Mao; Dominic G. Lucchetti; Peter M. Chen

2005-01-01

379

Thermal analysis of an enriched flame incinerator for aqueous residues  

Microsoft Academic Search

The use of oxygen to enrich the combustion air can be an attractive technique to increase capacity of an incinerator originally designed to operate with air. If incinerator parameters such as operation temperature, turbulence level and residence time are fixed for a certain fuel supply rate, it is possible to increase the residue consumption rate using enriched air. This paper

Pedro Teixeira Lacava; João A. Carvalho; Amilcar Porto Pimenta; Marco Aurélio Ferreira

2006-01-01

380

A case study of air enrichment in rotary kiln incineration  

Microsoft Academic Search

This paper presents a case study of air enrichment in an industrial rotary kiln type incineration unit. The study is based on mass and energy balances, considering the combustion reaction of a mixture composed by the residue and the auxiliary fuel with air enriched with oxygen. The steps are shown for the primary chamber (rotary kiln) and secondary chamber (afterburner).

J. A. Carvalho; P. T. Lacava

1998-01-01

381

Overview of reduced enrichment fuels: Development, testing, and specification  

SciTech Connect

The US Reduced Enrichment Research and Test Reactor (RERTR) Program was established in 1978 to provide the technical means to operate research and test reactors with low enrichment uranium (LEU) fuels without significant penalty in experiment performance, operation costs, component modifications, or safety characteristics. This paper discusses relevant developments in fuel developments. 9 refs., 1 tab.

Snelgrove, J.L.

1987-01-01

382

SINGLE ION TRAPPING FOR THE ENRICHED XENON OBSERVATORY  

E-print Network

SINGLE ION TRAPPING FOR THE ENRICHED XENON OBSERVATORY A DISSERTATION SUBMITTED TO THE DEPARTMENT. The Enriched Xenon Observatory for neutrinoless double beta decay (EXO) will search for the rare decays of xenon to determine the absolute value of the neutrino mass. The experiment uses a novel technique

Gratta, Giorgio

383

Metagenomic assessment of a sulfur-oxidizing enrichment culture derived from marine sediment  

Microsoft Academic Search

The biological oxidation of reduced sulfur compounds is a critically important process in global sulfur biogeochemistry. In\\u000a this study, we enriched from marine sediments under denitrifying conditions, chemolithotrophic sulfur oxidizers that could\\u000a oxidize a variety of reduced sulfur compounds: thiosulfate, tetrathionate, sulfide, and polysulfide. Two major phylotypes\\u000a of 16S rRNA gene (>99% identity in each phylotype) were detected in this

Man-Young Jung; VinhHoa Pham; Soo-Je Park; So-Jeong Kim; Jong-Chan Chae; Yul Roh; Sung-Keun Rhee

2010-01-01

384

Environmental Enrichment does not Reduce the Rewarding and Neurotoxic Effects of Methamphetamine  

Microsoft Academic Search

Abuse of amphetamine analogues, such as methamphetamine (METH), represents an important health problem because of their powerful\\u000a addictive and neurotoxic effects. Abuse of METH induces dopamine neuron terminals loss and cell death in the striatum similar\\u000a to what is found in other neurodegenerative processes. Exposing mice and rats to enriched environments (EE) has been shown\\u000a to produce significant protective effects

Nathalie Thiriet; Benjamin Gennequin; Virginie Lardeux; Claudia Chauvet; Mickael Decressac; Thierry Janet; Mohamed Jaber; Marcello Solinas

2011-01-01

385

Plasma CVD-Grown 10B-Enriched Boron Films for Si Neutron Detectors  

Microsoft Academic Search

Hydrogenated amorphous boron (a-B:H) films were deposited on Si crystal substrates using DC glow discharge in B2H6 diluted to 1000 ppm in H2. We found that the rate of the deposition was about two times higher for 10B-enriched B2H6 than for natural B2H6. The deposition process was observed by optical emission spectroscopy of the DC glow. BH emission lines at

Noritada Sato; Osamu Ishiwata; Yasukazu Seki; Atsushi Ueda

1990-01-01

386

Herbivore responses to nutrient enrichment and landscape heterogeneity in a mangrove ecosystem  

Microsoft Academic Search

Complex gradients in forest structure across the landscape of offshore mangrove islands in Belize are associated with nutrient\\u000a deficiency and flooding. While nutrient availability can affect many ecological processes, here we investigate how N and P\\u000a enrichment interact with forest structure in three distinct zones (fringe, transition, dwarf) to alter patterns of herbivory\\u000a as a function of folivory, loss of

Ilka C. Feller; Anne Chamberlain

2007-01-01

387

Simulating the metal enrichment of the ICM  

E-print Network

We present results from Tree+SPH simulations of a galaxy cluster, aimed at studying the metal enrichment of the intra--cluster medium (ICM). The simulation code includes a fairly advanced treatment of star formation, as well as the release of energy feedback and detailed yields from both type-II and type-Ia supernovae, also accurately accounting for the lifetimes of different stellar populations. We perform simulations of a cluster with virial mass ~ 3.9x 10^14 Msun, to investigate the effect of varying the feedback strength and the stellar initial mass function (IMF). Although most of the models are able to produce acceptable amounts of Fe mass, we find that the profiles of the iron abundance are always steeper than observed. The [O/Fe] ratio is found to be sub--solar for a Salpeter IMF, with [O/Fe] -0.2 at R >~ 0.1R200, whereas increasing to super-solar values in central regions, as a result of recent star formation. Using a top--heavier IMF gives a larger [O/Fe] over the whole cluster, at variance with obs...

Tornatore, L; Matteucci, F; Recchi, S; Tozzi, P

2004-01-01

388

Saturn's internal structure and carbon enrichment  

E-print Network

We use the clathrate hydrate trapping theory to calculate the enrichments in O, N, S, Xe, Ar and Kr compared to solar in Saturn's atmosphere. For this, we calibrate our calculations using two different carbon abundance determinations that cover the domain of measurements published in the last decades: one derived from the NASA $Kuiper$ Airborne Observatory measurements and the other obtained from the Cassini spacecraft observations. We show that these two different carbon abundances imply quite a different minimum heavy element content for Saturn. Using the Kuiper Airborne Observatory measurement for calibration, the amount of ices accreted by Saturn is found to be consistent with current interior models of this planet. On the other hand, using the Cassini measurement for calibration leads to an ice content in the planet's envelope which is higher than the one derived from the interior models. In this latter case, reconciling the interior models with the amount of C measured by the Cassini spacecraft requires that significant differential sedimentation of water and volatile species have taken place in Saturn's interior during its lifetime.

Olivier Mousis; Yann Alibert; Willy Benz

2005-11-14

389

Deuterium enrichment of the interstellar medium  

NASA Astrophysics Data System (ADS)

Despite the low elemental abundance of atomic deuterium in the interstellar medium (ISM), observational evidence suggests that several species, both in the gas phase and in ices, could be heavily fractionated. We explore various aspects of deuterium enrichment by constructing a chemical evolution model in both gaseous and granular phases. Depending on various physical parameters, gases and grains are allowed to interact with each other through the exchange of their chemical species. It is known that HCO+ and N2H+ are two abundant gas phase ions in the ISM and, their deuterium fractionation is generally used to predict the degree of ionization in the various regions of a molecular cloud. For a more accurate estimation, we consider the density profile of a collapsing cloud. The radial distributions of important interstellar molecules, along with their deuterated isotopomers, are presented. Quantum chemical simulations are computed to study the effects of isotopic substitution on the spectral properties of these interstellar species. We calculate the vibrational (harmonic) frequencies of the most important deuterated species (neutral and ions). The rotational and distortional constants of these molecules are also computed in order to predict the rotational transitions of these species. We compare vibrational (harmonic) and rotational transitions as computed by us with existing experimental and theoretical results. It is hope that our results will assist observers in detecting several hitherto unobserved deuterated species.

Das, Ankan; Majumdar, Liton; Chakrabarti, Sandip K.; Sahu, Dipen

2015-02-01

390

Identification, selection, and enrichment of cardiomyocyte precursors.  

PubMed

The large-scale production of cardiomyocytes is a key step in the development of cell therapy and tissue engineering to treat cardiovascular diseases, particularly those caused by ischemia. The main objective of this study was to establish a procedure for the efficient production of cardiomyocytes by reprogramming mesenchymal stem cells from adipose tissue. First, lentiviral vectors expressing neoR and GFP under the control of promoters expressed specifically during cardiomyogenesis were constructed to monitor cell reprogramming into precardiomyocytes and to select cells for amplification and characterization. Cellular reprogramming was performed using 5'-azacytidine followed by electroporation with plasmid pOKS2a, which expressed Oct4, Sox2, and Klf4. Under these conditions, GFP expression began only after transfection with pOKS2a, and less than 0.015% of cells were GFP(+). These GFP(+) cells were selected for G418 resistance to find molecular markers of cardiomyocytes by RT-PCR and immunocytochemistry. Both genetic and protein markers of cardiomyocytes were present in the selected cells, with some variations among them. Cell doubling time did not change after selection. Together, these results indicate that enrichment with vectors expressing GFP and neoR under cardiomyocyte-specific promoters can produce large numbers of cardiomyocyte precursors (CMPs), which can then be differentiated terminally for cell therapy and tissue engineering. PMID:23853770

Zanetti, Bianca Ferrarini; Gomes, Walter José; Han, Sang Won

2013-01-01

391

Opportunistic pathogens enriched in showerhead biofilms  

PubMed Central

The environments we humans encounter daily are sources of exposure to diverse microbial communities, some of potential concern to human health. In this study, we used culture-independent technology to investigate the microbial composition of biofilms inside showerheads as ecological assemblages in the human indoor environment. Showers are an important interface for human interaction with microbes through inhalation of aerosols, and showerhead waters have been implicated in disease. Although opportunistic pathogens commonly are cultured from shower facilities, there is little knowledge of either their prevalence or the nature of other microorganisms that may be delivered during shower usage. To determine the composition of showerhead biofilms and waters, we analyzed rRNA gene sequences from 45 showerhead sites around the United States. We find that variable and complex, but specific, microbial assemblages occur inside showerheads. Particularly striking was the finding that sequences representative of non-tuberculous mycobacteria (NTM) and other opportunistic human pathogens are enriched to high levels in many showerhead biofilms, >100-fold above background water contents. We conclude that showerheads may present a significant potential exposure to aerosolized microbes, including documented opportunistic pathogens. The health risk associated with showerhead microbiota needs investigation in persons with compromised immune or pulmonary systems. PMID:19805310

Feazel, Leah M.; Baumgartner, Laura K.; Peterson, Kristen L.; Frank, Daniel N.; Harris, J. Kirk; Pace, Norman R.

2009-01-01

392

ORIGIN OF LITHIUM ENRICHMENT IN K GIANTS  

SciTech Connect

In this Letter, we report on a low-resolution spectroscopic survey for Li-rich K giants among 2000 low-mass (M {<=} 3 M{sub sun}) giants spanning the luminosity range from below to above the luminosity of the clump. Fifteen new Li-rich giants including four super Li-rich K giants (log {epsilon}(Li) {>=}3.2) were discovered. A significant finding is that there is a concentration of Li-rich K giants at the luminosity of the clump or red horizontal branch. This new finding is partly a consequence of the fact that our low-resolution survey is the first large survey to include giants well below and above the red giant branch (RGB) bump and clump locations in the H-R diagram. Origin of the lithium enrichment may be plausibly attributed to the conversion of {sup 3}He via {sup 7}Be to {sup 7}Li by the Cameron-Fowler mechanism but the location for the onset of the conversion is uncertain. Two possible opportunities to effect this conversion are discussed: the bump in the first ascent of the RGB and the He-core flash at the tip of the RGB. The finite luminosity spread of the Li-rich giants serves to reject the idea that Li enhancement is, in general, a consequence of a giant swallowing a large planet.

Kumar, Yerra Bharat; Reddy, Bacham E. [Indian Institute of Astrophysics, Bengaluru 560034 (India); Lambert, David L. [McDonald Observatory, University of Texas, Austin, TX 78712 (United States)

2011-03-20

393

Formation and Preservation of the Depleted and Enriched Shergottite Isotopic Reservoirs in a Convecting Martian Mantle  

NASA Technical Reports Server (NTRS)

There is compelling isotopic and crater density evidence for geologically recent volcanism on Mars, in the last 100-200 million years and possibly in the last 50 million years. This volcanism is due to adiabatic decompression melting and thus requires some type of present-day convective upwelling in the martian mantle. On the other hand, martian meteorites preserve evidence for at least 3 distinct radiogenic isotopic reservoirs. Anomalies in short-lived isotopic systems (Sm-146, Nd-142, Hf-182, W-182) require that these reservoirs must have developed in the first 50 to 100 million years of Solar System history. The long-term preservation of chemically distinct reservoirs has sometimes been interpreted as evidence for the absence of mantle convection and convective mixing on Mars for most of martian history, a conclusion which is at odds with the evidence for young volcanism. This apparent paradox can be resolved by recognizing that a variety of processes, including both inefficient mantle mixing and geographic separation of isotopic reservoirs, may preserve isotopic heterogeneity on Mars in an actively convecting mantle. Here, we focus on the formation and preservation of the depleted and enriched isotopic and trace element reservoirs in the shergottites. In particular, we explore the possible roles of processes such as chemical diffusion and metasomatism in dikes and magma chambers for creating the isotopically enriched shergottites. We also consider processes that may preserve the enriched reservoir against convective mixing for most of martian history.

Kiefer, Walter S.; Jones, John H.

2015-01-01

394

Effect of Enrichment Medium on Real-time Detection of Salmonella enterica from Lettuce and Tomato Enrichment Cultures  

Technology Transfer Automated Retrieval System (TEKTRAN)

vThree commonly used enrichment broths for detection of Salmonella (Buffered Peptone Water – BPW, Tryptic Soy Broth – TSB, and Universal Preenrichment Broth – UPB) were compared for use in real time SYBR Green PCR detection of Salmonella introduced into enrichment cultures made from store bought let...

395

Interrill sediment enrichment of P and C from organically and conventionally farmed silty loams  

NASA Astrophysics Data System (ADS)

Globally, between 0.57 and 1.33 Pg of soil organic carbon (SOC) may be affected by interrill processes. Also, a significant amount of phosphorus (P) is contained in the surface soil layer transformed by raindrop impact, runoff and crust formation. In the EU, the P content of a crusted (2 mm) surface layer corresponds to 4 to 40 kg ha-1 of P on arable land (1.094 mil km2). Therefore, the role of interrill processes for nutrient cycling and the global carbon cycle requires close attention. Interrill erosion is a complex phenomen on involving the detachment, transport and deposition of soil particles by raindrop impacted flow. Resistance to interrill erosion varies between soils depending on their physical, chemical and mineralogical properties. In addition, significant changes in soil resistance to interrill erosion occur during storms as a result of changes in surface roughness, cohesion and particle size. As a consequence, erosion on interrill areas is selective, moving the most easily detached small and/or light soil particles. This leads to the enrichment of clay, phosphorous (P)and carbon (C). Such enrichment in interrill sediment is well documented, however, the role of interrill erosion processes on the enrichment remains unclear. Enrichment of P and C in interrill sediment is attributed to the preferential erosion of the smaller, lighter soil particles. In this study, the P and organic C content of sediment generated from two Devon silts under conventional (CS) and organic (OS) soil management were examined. Artificial rainfall was applied to the soils using two rainfall scenarios of differing intensity and kinetic energy to determine the effects on the P and C enrichment in interrill sediment. Interrill soil erodibility was lower on the OS, irrespective of rainfall intensity. Sediment from both soils showed a significant enrichment in P and C compared to the bulk soil. However, sediment from the OS displayed a much greater degree of P enrichment. This shows that the net P export from organically farmed soils is not reduced by a similar degree than soil erosion compared to conventional soil management. The enrichment of P and C in the interrill sediment was not directly related to SOC, P content of the soil and soil interrill erodibility. A comparison of soil and sediment properties indicates that crusting, P and C content as well as density and size of eroded aggregate fragments control P and C enrichment. Due to complex and dynamic interactions between P, SOC and interrill erosional processes, the nutrient and C status of sediments cannot be predicted based on soil P content, SOC or interrill erodibility alone. Clearly, further research on crust formation and the composition of fragments generated by aggregate breakdown and their transport in raindrop impacted flow under different rainfall conditions is required. Attaining this critical missing knowledge would enable a comprehensive assessment of the benefits of organic farming on nutrient budgets, off-site effects of interrill erosion and its role in the global C cycle.

Kuhn, N. J.

2012-04-01

396

Enzymatic synthesis of extremely pure triacylglycerols enriched in conjugated linoleic acids.  

PubMed

This work was objectively targeted to synthesize extremely pure triacylglycerols (TAG) enriched in conjugated linoleic acids (CLAs) for medical and dietetic purposes. Extremely pure CLA-enriched TAG was successfully synthesized by using the multi-step process: TAG was primarily synthesized by lipase-catalyzed esterification of CLA and glycerol and then the lower glycerides [monoacylglycerol (MAG) and diacylglycerol (DAG)] in the esterification mixtures was hydrolyzed to free fatty acids (FFAs) by a mono- and di-acylglycerol lipase (lipase SMG1), finally, the FFAs were further separated from TAG by low temperature (150 °C) molecular distillation. The operation parameters for the lipase SMG1-catalyzed hydrolysis were optimized using response surface methodology based on the central composite rotatable design (CCRD). The operation parameters included water content, pH and reaction temperature and all of these three parameters showed significant effects on the hydrolysis of lower glycerides. The optimal conditions were obtained with a water content of 66.4% (w/w, with respect to oil mass), pH at 5.7 and 1 h of reaction time at 19.6 °C. Under these conditions, the content of lower glycerides in the reaction mixture decreased from 45.2% to 0.3% and the purity of CLA-enriched TAG reached 99.7%. Further purification of TAG was accomplished by molecular distillation and the final CLA-enriched TAG product yielded 99.8% of TAG. These extremely pure CLA-enriched TAG would be used for in vivo studies in animals and humans in order to get speci?c information concerning CLA metabolism. PMID:23945644

Cao, Yu; Wang, Weifei; Xu, Yang; Yang, Bo; Wang, Yonghua

2013-01-01

397

From sets to graphs: towards a realistic enrichment analysis of transcriptomic systems  

PubMed Central

Motivation: Current gene set enrichment approaches do not take interactions and associations between set members into account. Mutual activation and inhibition causing positive and negative correlation among set members are thus neglected. As a consequence, inconsistent regulations and contextless expression changes are reported and, thus, the biological interpretation of the result is impeded. Results: We analyzed established gene set enrichment methods and their result sets in a large-scale investigation of 1000 expression datasets. The reported statistically significant gene sets exhibit only average consistency between the observed patterns of differential expression and known regulatory interactions. We present Gene Graph Enrichment Analysis (GGEA) to detect consistently and coherently enriched gene sets, based on prior knowledge derived from directed gene regulatory networks. Firstly, GGEA improves the concordance of pairwise regulation with individual expression changes in respective pairs of regulating and regulated genes, compared with set enrichment methods. Secondly, GGEA yields result sets where a large fraction of relevant expression changes can be explained by nearby regulators, such as transcription factors, again improving on set-based methods. Thirdly, we demonstrate in additional case studies that GGEA can be applied to human regulatory pathways, where it sensitively detects very specific regulation processes, which are altered in tumors of the central nervous system. GGEA significantly increases the detection of gene sets where measured positively or negatively correlated expression patterns coincide with directed inducing or repressing relationships, thus facilitating further interpretation of gene expression data. Availability: The method and accompanying visualization capabilities have been bundled into an R package and tied to a grahical user interface, the Galaxy workflow environment, that is running as a web server. Contact: Ludwig.Geistlinger@bio.ifi.lmu.de; Ralf.Zimmer@bio.ifi.lmu.de PMID:21685094

Geistlinger, Ludwig; Csaba, Gergely; Küffner, Robert; Mulder, Nicola; Zimmer, Ralf

2011-01-01

398

Salt enrichment of municipal sewage: New prevention approaches in Israel  

NASA Astrophysics Data System (ADS)

Wastewater irrigation is an environmentally sound wastewater disposal practice, but sewage is more saline than the supplied fresh water and the salts are recycled together with the water. Salts have negative environmental effects on crops, soils, and groundwater. There are no inexpensive ways to remove the salts once they enter sewage, and the prevention of sewage salt enrichment is the most immediately available solution. The body of initiatives presently structured by the Ministry of the Environment of Israel are herein described, with the aim to contribute to the search for a long-term solution of salinity problems in arid countries. The new initiatives are based on: (1) search for new technologies to reduce salt consumption and discharge into sewage; (2) different technologies to cope with different situations; (3) raising the awareness of the public and industry on the environmental implications of salinity pollution; and (4) an elastic legal approach expressed through new state-of-the-art regulations. The main contributor to the salinity of sewage in Israel is the watersoftening process followed by the meat koshering process. Some of the adopted technical solutions are: the discharge of the brine into the sea, the substitution of sodium by potassium salts in the ion-exchangers, the construction of centralized systems for the supply of soft water in industrial areas, the precipitation of Ca and Mg in the effluents from ion-exchangers and recycling of the NaCI solution, a reduction of the discharge of salts by the meat koshering process, and new membrane technology for salt recovery.

Weber, Baruch; Avnimelech, Yoram; Juanico, Marcelo

1996-07-01

399

Environmental Enrichment for Primates: Annotated Database on Environmental Enrichment and Refinement of Husbandry for Nonhuman Primates  

NSDL National Science Digital Library

The Animal Welfare Institute, a nonprofit organization founded "to reduce the sum total of pain and fear inflicted on animals by humans," offers this frequently updated bibliographic database for information on all aspects of environmental enrichment for nonhuman primates. Search results include a list of relevant references with complete bibliographic information, brief summaries of each entry, Web links to full-text documents where available, and a keyword index for easily finding related sources. Users may also browse the entire contents of the database alphabetically. Primatologists and animal handlers alike should find this comprehensive database particularly useful.

400

A flax fibre proteome: identification of proteins enriched in bast fibres  

PubMed Central

Background Bast fibres from the phloem tissues of flax are scientifically interesting and economically useful due in part to a dynamic system of secondary cell wall deposition. To better understand the molecular mechanisms underlying the process of cell wall development in flax, we extracted proteins from individually dissected phloem fibres (i.e. individual cells) at an early stage of secondary cell wall development, and compared these extracts to protein extracts from surrounding, non-fibre cells of the cortex, using fluorescent (DiGE) labels and 2D-gel electrophoresis, with identities assigned to some proteins by mass spectrometry. Results The abundance of many proteins in fibres was notably different from the surrounding non-fibre cells of the cortex, with approximately 13% of the 1,850 detectable spots being significantly (> 1.5 fold, p ? 0.05) enriched in fibres. Following mass spectrometry, we assigned identity to 114 spots, of which 51 were significantly enriched in fibres. We observed that a K+ channel subunit, annexins, porins, secretory pathway components, ?-amylase, ?-galactosidase and pectin and galactan biosynthetic enzymes were among the most highly enriched proteins detected in developing flax fibres, with many of these proteins showing electrophoretic patterns consistent with post-translational modifications. Conclusion The fibre-enriched proteins we identified are consistent with the dynamic process of secondary wall deposition previously suggested by histological and biochemical analyses, and particularly the importance of galactans and the secretory pathway in this process. The apparent abundance of ?-amylase suggests that starch may be an unappreciated source of materials for cell wall biogenesis in flax bast fibres. Furthermore, our observations confirm previous reports that correlate accumulation proteins such as annexins, and specific heat shock proteins with secondary cell wall deposition. PMID:18447950

Hotte, Naomi SC; Deyholos, Michael K

2008-01-01

401

Nutrient Enrichment and Food Web Composition Affect Ecosystem Metabolism in an Experimental Seagrass Habitat  

PubMed Central

Background Food web composition and resource levels can influence ecosystem properties such as productivity and elemental cycles. In particular, herbivores occupy a central place in food webs as the species richness and composition of this trophic level may simultaneously influence the transmission of resource and predator effects to higher and lower trophic levels, respectively. Yet, these interactions are poorly understood. Methodology/Principal Findings Using an experimental seagrass mesocosm system, we factorially manipulated water column nutrient concentrations, food chain length, and diversity of crustacean grazers to address two questions: (1) Does food web composition modulate the effects of nutrient enrichment on plant and grazer biomasses and stoichiometry? (2) Do ecosystem fluxes of dissolved oxygen and nutrients more closely reflect above-ground biomass and community structure or sediment processes? Nutrient enrichment and grazer presence generally had strong effects on biomass accumulation, stoichiometry, and ecosystem fluxes, whereas predator effects were weaker or absent. Nutrient enrichment had little effect on producer biomass or net ecosystem production but strongly increased seagrass nutrient content, ecosystem flux rates, and grazer secondary production, suggesting that enhanced production was efficiently transferred from producers to herbivores. Gross ecosystem production (oxygen evolution) correlated positively with above-ground plant biomass, whereas inorganic nutrient fluxes were unrelated to plant or grazer biomasses, suggesting dominance by sediment microbial processes. Finally, grazer richness significantly stabilized ecosystem processes, as predators decreased ecosystem production and respiration only in the zero- and one- species grazer treatments. Conclusions/Significance Overall, our results indicate that consumer presence and species composition strongly influence ecosystem responses to nutrient enrichment, and that increasing herbivore diversity can stabilize ecosystem flux rates in the face of perturbations. PMID:19829713

Spivak, Amanda C.; Canuel, Elizabeth A.; Duffy, J. Emmett; Richardson, J. Paul

2009-01-01

402

Polymer-Enriched 3D Graphene Foams for Biomedical Applications.  

PubMed

Graphene foams (GFs) are versatile nanoplatforms for biomedical applications because of their excellent physical, chemical, and mechanical properties. However, the brittleness and inflexibility of pristine GF (pGF) are some of the important factors restricting their widespread application. Here, a chemical-vapor-deposition-assisted method was used to synthesize 3D GFs, which were subsequently spin-coated with polymer to produce polymer-enriched 3D GFs with high conductivity and flexibility. Compared to pGF, both poly(vinylidene fluoride)-enriched GF (PVDF/GF) and polycaprolactone-enriched GF (PCL/GF) scaffolds showed improved flexibility and handleability. Despite the presence of the polymers, the polymer-enriched 3D GF scaffolds retained high levels of electrical conductivity because of the presence of microcracks that allowed for the flow of electrons through the material. In addition, polymer enrichment of GF led to an enhancement in the formation of calcium phosphate (Ca-P) compounds when the scaffolds were exposed to simulated body fluid. Between the two polymers tested, PCL enrichment of GF resulted in a higher in vitro mineralization nucleation rate because the oxygen-containing functional group of PCL had a higher affinity for Ca-P deposition and formation compared to the polar carbon-fluorine (C-F) bond in PVDF. Taken together, our current findings are a stepping stone toward future applications of polymer-enriched 3D GFs in the treatment of bone defects as well as other biomedical applications. PMID:25822669

Wang, Jun Kit; Xiong, Gordon Minru; Zhu, Minmin; Özyilmaz, Barbaros; Castro Neto, Antonio Helio; Tan, Nguan Soon; Choong, Cleo

2015-04-22

403

Thermal infrared emission spectroscopy of titanium-enriched pyroxenes  

NASA Astrophysics Data System (ADS)

Pyroxenes are useful indicators of igneous processes and may be identified in geologic materials in the laboratory or remotely through the use of spectroscopic analysis. Studies of the thermal infrared (vibrational) spectra of many compositions in the pyroxene solid solution series (quadrilateral orthopyroxene and clinopyroxene, and some nonquadrilateral compositions) have shown that spectral absorption features shift in wavelength position, vary in number, and change shape as a function of pyroxene silicate structure and cation substitution. These spectral variations can be used to identify the approximate composition(s) of pyroxenes in the thermal infrared emission spectra of rocks. Here I demonstrate that the spectra of Ti-rich calcic clinopyroxenes also have thermal infrared spectral characteristics that distinguish them from typical quadrilateral compositions via a comparison to the spectrum of Angra dos Reis, a meteorite dominated by Ti-enriched clinopyroxene. The distinctive spectral character of Ti-rich pyroxenes may permit their identification not only in laboratory mineral and rock samples but also in thermal infrared remote sensing data, providing additional chemical information about igneous lithologies.

Hamilton, V. E.

2003-08-01

404

Copper enrichment in arc magmas controlled by overriding plate thickness  

NASA Astrophysics Data System (ADS)

Porphyry copper systems supply about 75% of the world's copper. They form above subduction zones and are preferentially associated with calc-alkaline magmas. Such magmas result from continuous iron depletion during differentiation, in contrast to tholeiitic magmas that show initial iron enrichment during differentiation. The formation of calc-alkaline magmas is favoured by high water content and oxygen fugacity. These characteristics, as well as magmatic metal contents, are thought to be imparted in the mantle source by fluids of the subducted slab. Yet this process does not explain why porphyry copper systems preferentially occur in thicker arcs. Here I present a statistical assessment of more than 40,000 published geochemical analyses of magmatic rocks from 23 Quaternary-aged volcanic arcs worldwide. I find that magmas of thicker arcs are systematically more calc-alkaline and more depleted in copper than magmas of thinner arcs. This implies that the missing copper in the former accumulates as copper sulphides within or at the base of thicker arcs. Such copper accumulations are an essential step in forming porphyry systems. These results suggest that the thickness of the overriding plate provides a more important control on magma differentiation than the composition of the mantle source, and can explain the preferential association of porphyry copper systems with calc-alkaline magmas and thicker arcs.

Chiaradia, Massimo

2014-01-01

405

Enrichment by supernovae in globular clusters with multiple populations.  

PubMed

The most massive globular cluster in the Milky Way, omega Centauri, is thought to be the remaining core of a disrupted dwarf galaxy, as expected within the model of hierarchical merging. It contains several stellar populations having different heavy elemental abundances supplied by supernovae-a process known as metal enrichment. Although M 22 appears to be similar to omega Cen, other peculiar globular clusters do not. Therefore omega Cen and M 22 are viewed as exceptional, and the presence of chemical inhomogeneities in other clusters is seen as 'pollution' from the intermediate-mass asymptotic-giant-branch stars expected in normal globular clusters. Here we report Ca abundances for seven globular clusters and compare them to omega Cen. Calcium and other heavy elements can only be supplied through numerous supernovae explosions of massive stars in these stellar systems, but the gravitational potentials of the present-day clusters cannot preserve most of the ejecta from such explosions. We conclude that these globular clusters, like omega Cen, are most probably the relics of more massive primeval dwarf galaxies that merged and disrupted to form the proto-Galaxy. PMID:19940919

Lee, Jae-Woo; Kang, Young-Woon; Lee, Jina; Lee, Young-Wook

2009-11-26

406

Enriching rice with Zn and Fe while minimizing Cd risk.  

PubMed

Enriching iron (Fe) and zinc (Zn) content in rice grains, while minimizing cadmium (Cd) levels, is important for human health and nutrition. Natural genetic variation in rice grain Zn enables Zn-biofortification through conventional breeding, but limited natural Fe variation has led to a need for genetic modification approaches, including over-expressing genes responsible for Fe storage, chelators, and transporters. Generally, Cd uptake and allocation is associated with divalent metal cations (including Fe and Zn) transporters, but the details of this process are still unknown in rice. In addition to genetic variation, metal uptake is sometimes limited by its bioavailability in the soil. The availability of Fe, Zn, and Cd for plant uptake varies widely depending on soil redox potential. The typical practice of flooding rice increases Fe while decreasing Zn and Cd availability. On the other hand, moderate soil drying improves Zn uptake but also increases Cd and decreases Fe uptake. Use of Zn- or Fe-containing fertilizers complements breeding efforts by providing sufficient metals for plant uptake. In addition, the timing of nitrogen fertilization has also been shown to affect metal accumulation in grains. The purpose of this mini-review is to identify knowledge gaps and prioritize strategies for improving the nutritional value and safety of rice. PMID:25814994

Slamet-Loedin, Inez H; Johnson-Beebout, Sarah E; Impa, Somayanda; Tsakirpaloglou, Nikolaos

2015-01-01

407

Enriching rice with Zn and Fe while minimizing Cd risk  

PubMed Central

Enriching iron (Fe) and zinc (Zn) content in rice grains, while minimizing cadmium (Cd) levels, is important for human health and nutrition. Natural genetic variation in rice grain Zn enables Zn-biofortification through conventional breeding, but limited natural Fe variation has led to a need for genetic modification approaches, including over-expressing genes responsible for Fe storage, chelators, and transporters. Generally, Cd uptake and allocation is associated with divalent metal cations (including Fe and Zn) transporters, but the details of this process are still unknown in rice. In addition to genetic variation, metal uptake is sometimes limited by its bioavailability in the soil. The availability of Fe, Zn, and Cd for plant uptake varies widely depending on soil redox potential. The typical practice of flooding rice increases Fe while decreasing Zn and Cd availability. On the other hand, moderate soil drying improves Zn uptake but also increases Cd and decreases Fe uptake. Use of Zn- or Fe-containing fertilizers complements breeding efforts by providing sufficient metals for plant uptake. In addition, the timing of nitrogen fertilization has also been shown to affect metal accumulation in grains. The purpose of this mini-review is to identify knowledge gaps and prioritize strategies for improving the nutritional value and safety of rice.

Slamet-Loedin, Inez H.; Johnson-Beebout, Sarah E.; Impa, Somayanda; Tsakirpaloglou, Nikolaos

2015-01-01

408

Producing and quantifying enriched para-H2  

NASA Astrophysics Data System (ADS)

The production of enriched para-H2 is useful for many scientific applications, but the technology for producing and measuring para-H2 is not yet widespread. In this note and in the accompanying auxiliary material, we describe the design, construction, and use of a versatile standalone converter that is capable of producing para-H2 enrichments of up to ?99.99% at continuous flow rates of up to 0.4 SLM. We also discuss para-H2 storage and back conversion rates, and improvements to three techniques (thermal conductance, NMR, and solid hydrogen impurity spectroscopy) used to quantify the para-H2 enrichment.

Tom, Brian A.; Bhasker, Siddhartha; Miyamoto, Yuki; Momose, Takamasa; McCall, Benjamin J.

2009-01-01

409

N-glycoprotein enrichment by lectin affinity chromatography.  

PubMed

Lectins are proteins that bind to sugars with varying specificities and several have been identified that show differential binding to structurally variable glycans attached to glycoproteins. Consequently, lectin affinity chromatography represents a valuable tool for glycoproteome studies, allowing enrichment of glycoproteins in samples prior to their identification by mass spectrometry (MS). From the perspective of plant scientists, lectin enrichment has proven useful for studies of the proteomes of the secretory pathways and cell wall, due to the high proportion of constituent proteins that are glycosylated. This chapter outlines a strategy to generate samples enriched with glycoproteins from bulk plant tissues prior to further characterization by MS, or other techniques. PMID:24136552

Ruiz-May, Eliel; Catalá, Carmen; Rose, Jocelyn K C

2014-01-01

410

Fire extinguishing agents for oxygen-enriched atmospheres  

NASA Astrophysics Data System (ADS)

Fire-suppression agent requirements for extinguishing fires in oxygen-enriched atmospheres were determined employing small-, medium-, large-, and full-scale test apparatuses. The small- and medium-scale tests showed that a doubling of the oxygen concentration required five times more HALON for extinguishment. For fires of similar size and intensity, the effect of oxygen enrichment of the diluent volume in the HC-131A was not as grate as in the smaller compartments of the B-52 which presented a higher damage scenario. The full-scale tests showed that damage to the airframe was as important a factor in extinguishment as oxygen enrichment.

Plugge, M. A.; Wilson, C. W.; Zallen, D. M.; Walker, J. L.

1985-12-01

411

Realities of verifying the absence of highly enriched uranium (HEU) in gas centrifuge enrichment plants  

SciTech Connect

Over a two and one-half year period beginning in 1981, representatives of six countries (United States, United Kingdom, Federal Republic of Germany, Australia, The Netherlands, and Japan) and the inspectorate organizations of the International Atomic Energy Agency and EURATOM developed and agreed to a technically sound approach for verifying the absence of highly enriched uranium (HEU) in gas centrifuge enrichment plants. This effort, known as the Hexapartite Safeguards Project (HSP), led to the first international concensus on techniques and requirements for effective verification of the absence of weapons-grade nuclear materials production. Since that agreement, research and development has continued on the radiation detection technology-based technique that technically confirms the HSP goal is achievable. However, the realities of achieving the HSP goal of effective technical verification have not yet been fully attained. Issues such as design and operating conditions unique to each gas centrifuge plant, concern about the potential for sensitive technology disclosures, and on-site support requirements have hindered full implementation and operator support of the HSP agreement. In future arms control treaties that may limit or monitor fissile material production, the negotiators must recognize and account for the realities and practicalities in verifying the absence of HEU production. This paper will describe the experiences and realities of trying to achieve the goal of developing and implementing an effective approach for verifying the absence of HEU production. 3 figs.

Swindle, D.W.

1990-03-01

412

Isotopologue enrichment factors of N(2)O reduction in soils.  

PubMed

Isotopic signatures can be used to study sink and source processes of N(2)O, but the success of this approach is limited by insufficient knowledge on the isotope fractionation factors of the various reaction pathways. We investigated isotope enrichment factors of the N(2)O-to-N(2) step of denitrification (epsilon) in two arable soils, a silt-loam Haplic Luvisol and a sandy Gleyic Podzol. In addition to the epsilon of (18)O (epsilon(18O)) and of average (15)N (epsilon(bulk)), the epsilon of the (15)N site preference within the linear N(2)O molecule (epsilon(SP)) was also determined. Soils were anaerobically incubated in gas-tight bottles with N(2)O added to the headspace to induce N(2)O reduction. Pre-treatment included the removal of NO(3) (-) to prevent N(2)O production. Gas samples were collected regularly to determine the dynamics of N(2)O reduction, the time course of the isotopic signatures of residual N(2)O, and the associated isotope enrichment factors. To vary reduction rates and associated fractionation factors, several treatments were established including two levels of initial N(2)O concentration and anaerobic pre-incubation with or without addition of N(2)O. N(2)O reduction rates were affected by the soil type and initial N(2)O concentration. The epsilon(18O) and epsilon(bulk) ranged between -13 and -20 per thousand, and between -5 and -9 per thousand, respectively. Both quantities were more negative in the Gleyic Podzol. The epsilon of the central N position (epsilon(alpha)) was always larger than that of the peripheral N-position (epsilon(beta)), giving epsilon(SP) of -4 to -8 per thousand. The ranges and variation patterns of epsilon were comparable with those from previous static incubation studies with soils. Moreover, we found a relatively constant ratio between epsilon(18O) and epsilon(bulk) which is close to the default ratio of 2.5 that had been previously suggested. The fact that different soils exhibited comparable epsilon under certain conditions suggests that these values could serve to identify N(2)O reduction from the isotopic fingerprints of N(2)O emitted from any soil. PMID:19681096

Well, R; Flessa, H

2009-09-01

413

77 FR 60482 - Regulatory Guide 5.67, Material Control and Accounting for Uranium Enrichment Facilities...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Material Control and Accounting for Uranium Enrichment Facilities Authorized To Produce...Material Control and Accounting for Uranium Enrichment Facilities Authorized to Produce...FNMC) Plan Required for Low-Enriched Uranium Facilities'' which was issued in...

2012-10-03

414

78 FR 66898 - Low Enriched Uranium From France: Final Results of Changed Circumstances Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-427-818] Low Enriched Uranium From France: Final Results of Changed...of one specified entry of low enriched uranium (LEU) that entered under a narrow provision...1\\ See Low Enriched Uranium from France: Initiation of...

2013-11-07

415

10 CFR 40.33 - Issuance of a license for a uranium enrichment facility.  

Code of Federal Regulations, 2014 CFR

... false Issuance of a license for a uranium enrichment facility. 40.33 Section...40.33 Issuance of a license for a uranium enrichment facility. (a) The...of the construction and operation of a uranium enrichment facility. The...

2014-01-01

416

10 CFR 140.13b - Amount of liability insurance required for uranium enrichment facilities.  

Code of Federal Regulations, 2013 CFR

...Amount of liability insurance required for uranium enrichment facilities. 140.13b ...Amount of liability insurance required for uranium enrichment facilities. Each holder...under Parts 40 or 70 of this chapter for a uranium enrichment facility that...

2013-01-01

417

10 CFR 140.13b - Amount of liability insurance required for uranium enrichment facilities.  

Code of Federal Regulations, 2010 CFR

...Amount of liability insurance required for uranium enrichment facilities. 140.13b ...Amount of liability insurance required for uranium enrichment facilities. Each holder...under Parts 40 or 70 of this chapter for a uranium enrichment facility that...

2010-01-01

418

10 CFR 40.33 - Issuance of a license for a uranium enrichment facility.  

Code of Federal Regulations, 2013 CFR

... false Issuance of a license for a uranium enrichment facility. 40.33 Section...40.33 Issuance of a license for a uranium enrichment facility. (a) The...of the construction and operation of a uranium enrichment facility. The...

2013-01-01

419

10 CFR 40.33 - Issuance of a license for a uranium enrichment facility.  

Code of Federal Regulations, 2012 CFR

... false Issuance of a license for a uranium enrichment facility. 40.33 Section...40.33 Issuance of a license for a uranium enrichment facility. (a) The...of the construction and operation of a uranium enrichment facility. The...

2012-01-01

420

10 CFR 40.33 - Issuance of a license for a uranium enrichment facility.  

Code of Federal Regulations, 2010 CFR

... false Issuance of a license for a uranium enrichment facility. 40.33 Section...40.33 Issuance of a license for a uranium enrichment facility. (a) The...of the construction and operation of a uranium enrichment facility. The...

2010-01-01

421

77 FR 19642 - Low Enriched Uranium From France: Final Results of Antidumping Duty Changed Circumstances Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-427-818] Low Enriched Uranium From France: Final Results of Antidumping...antidumping duty order on low enriched uranium (LEU) from France on February 10, 2012...1\\ See Low Enriched Uranium from France: Preliminary Results of...

2012-04-02

422

10 CFR 140.13b - Amount of liability insurance required for uranium enrichment facilities.  

Code of Federal Regulations, 2014 CFR

...Amount of liability insurance required for uranium enrichment facilities. 140.13b ...Amount of liability insurance required for uranium enrichment facilities. Each holder...under Parts 40 or 70 of this chapter for a uranium enrichment facility that...

2014-01-01

423

10 CFR 40.33 - Issuance of a license for a uranium enrichment facility.  

Code of Federal Regulations, 2011 CFR

... false Issuance of a license for a uranium enrichment facility. 40.33 Section...40.33 Issuance of a license for a uranium enrichment facility. (a) The...of the construction and operation of a uranium enrichment facility. The...

2011-01-01

424

77 FR 7128 - Low Enriched Uranium From France: Preliminary Results of Antidumping Duty Changed Circumstances...  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-427-818] Low Enriched Uranium From France: Preliminary Results of Antidumping...antidumping duty order of low enriched uranium (LEU) from France.\\1\\ We preliminarily...1\\ See Low Enriched Uranium from France: Initiation of...

2012-02-10

425

3 CFR - Continuation of the National Emergency With Respect to the Disposition of Russian Highly Enriched...  

Code of Federal Regulations, 2014 CFR

...Disposition of Russian Highly Enriched Uranium Presidential Documents Other Presidential...Disposition of Russian Highly Enriched Uranium On June 25, 2012, by Executive...Concerning the Disposition of Highly Enriched Uranium Extracted from Nuclear Weapons,...

2014-01-01

426

10 CFR 140.13b - Amount of liability insurance required for uranium enrichment facilities.  

Code of Federal Regulations, 2011 CFR

...Amount of liability insurance required for uranium enrichment facilities. 140.13b ...Amount of liability insurance required for uranium enrichment facilities. Each holder...under Parts 40 or 70 of this chapter for a uranium enrichment facility that...

2011-01-01

427

10 CFR 140.13b - Amount of liability insurance required for uranium enrichment facilities.  

Code of Federal Regulations, 2012 CFR

...Amount of liability insurance required for uranium enrichment facilities. 140.13b ...Amount of liability insurance required for uranium enrichment facilities. Each holder...under Parts 40 or 70 of this chapter for a uranium enrichment facility that...

2012-01-01

428

77 FR 1059 - Low Enriched Uranium From France: Initiation of Antidumping Duty Changed Circumstances Review  

Federal Register 2010, 2011, 2012, 2013, 2014

...Administration [A-427-818] Low Enriched Uranium From France: Initiation of Antidumping...antidumping duty order on low enriched uranium (LEU) from France with respect to Eurodif...See Letter from AREVA, ``Low Enriched Uranium from France,'' dated December...

2012-01-09

429

Liquid Emulsion Membrane (LEM) Process for Vanadium (IV) Enrichment: Process Intensification  

Microsoft Academic Search

A liquid emulsion membrane (LEM) system for vanadium (IV) transport has been designed using di?2?ethylhexyl phosphoric acid (D2EHPA), dissolved in n?dodecane as carrier. The selection of extractant, D2EHPA, was made on the basis of conventional liquid?liquid extraction studies. The work has been undertaken by first carrying out liquid?liquid extraction studies for vanadium (IV) to get stoichiometric constant (n), and equilibrium

Suresh V. Yadav; Vijaykumar V. Mahajani

2007-01-01

430

DETECTION OF SALMONELLA FROM POST-CHILL BROILER CARCASSES BY RINSE ALIQUOT AND WHOLE CARCASS ENRICHMENT METHODS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The objective of this study was to compare the recovery of salmonellae using a rinse aliquot method and a whole carcass enrichment method. Broiler carcasses were collected from a commercial processing plant immediately after a single tank immersion chiller. Carcasses were individually bagged and t...

431

Fabrication and microstructural characterization of Al/Zn-enriched layers on pure magnesium  

SciTech Connect

Al/Zn-enriched surface layers were fabricated by heating Mg specimens in contact with Al–Zn powder mixtures in a vacuum furnace at 445 °C. The layer formation process took place through partial melting at the Mg-substrate/powder-mixture interface. Heating times ranged from 20 to 80 min. The layer microstructure and composition were analyzed by optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The layers were 100–900 ?m in thickness, depending on the treatment time. The examination results revealed that the layers consisted of Mg{sub 17}(Al,Zn){sub 12} and Mg{sub 5}Al{sub 2}Zn{sub 2} intermetallic phases and a solid solution of Al and Zn in Mg. Between the Al/Zn-enriched layer and the Mg substrate, there was a transition zone of a solid solution of Al and Zn in Mg with a thickness of 20–30 ?m. The layers had much higher microhardness than the Mg substrate. - Highlights: ? The layers were produced by heating Mg in contact with an Al–Zn powder mixture. ? The layer formation process at 445 °C proceeded with the liquid phase contribution. ? The Al/Zn-enriched layers were thick, dense, uniform and continuous. ? The layers contained Mg–Al–Zn intermetallic phases. ? The hardness of the layers was much higher than that of the Mg substrate.

Mola, Renata, E-mail: rmola@tu.kielce.pl

2013-04-15

432

Freeze concentration for enrichment of nutrients in yellow water from no-mix toilets.  

PubMed

Separately collected urine ("yellow water") can be utilized as fertilizer. In order to decrease storage volumes and energy consumption for yellow water transport to fields, enrichment of nutrients in yellow water has to be considered. Laboratory-scale batch freeze concentration of yellow water has been tested in ice-front freezing apparatus: a stirred vessel and a falling film freeze concentrator (coolant temperatures: -6 to -16 degrees C). With progressing enrichment of the liquid concentrate, the frozen ice was increasingly contaminated with yellow water constituents (ammonia, total nitrogen, total phosphorus, TOC, and salts determined as conductivity). The higher the initial salinity of the yellow water and the lower the mechanical agitation of the liquid phase contacting the growing ice front, the more the frozen ice was contaminated. The results indicate, that in ice-front freezing devices multistage processes are necessary, i.e. the melted ice phase has to be purified (and the concentrates must be further enriched) in a second or even in a third stage. Energy consumption of this process is very high. However, technical scale suspension freeze concentration is reasonable in centralized ecological sanitation schemes if the population exceeds 0.5 million and distance of yellow water transportation to fields is more than 80 km. PMID:15536991

Gulyas, H; Bruhn, P; Furmanska, M; Hartrampf, K; Kot, K; Lüttenberg, B; Mahmood, Z; Stelmaszewska, K; Otterpohl, R

2004-01-01

433

Chemical Enrichment and Physical Conditions in IZw18*  

NASA Technical Reports Server (NTRS)

Low-metallicity star-forming dwarf galaxies are prime targets to understand the chemical enrichment of the interstellar medium. The H I region contains the bulk of the mass in blue compact dwarfs, and it provides important constraints on the dispersal and mixing of heavy elements released by successive star-formation episodes. The metallicity of the H I region is also a critical parameter to investigate the future star-formation history, as metals provide most of the gas cooling that will facilitate and sustain star formation. Aims. Our primary objective is to study the enrichment of the H I region and the interplay between star-formation history and metallicity evolution. Our secondary obje ctive is to constrain the spatial- and time-scales over which the HI and H II regions are enriched, and the mass range of stars responsible for the heavy element production. Finally, we aim to examine the gas heating and cooling mechanisms in the H I region. Methods. We observed the most metal-poor star-forming galaxy in the Local Universe, I Zw 18, with the Cosmic Origin Spectrograph onboard Hubble. The abundances in the neutral gas are derived from far-ultraviolet absorption-lines (H I, CIII, CIIi*, N I, OI,...) and are compared to the abundances in the H II region. Models are constructed to calculate the ionization structure and the thermal processes. We investigate the gas cooling in the HIi region through physical diagnostics drawn from the fine-structure level of C+. Results. We find that H I region abundances are lower by a factor of approx 2 as compared to the H II region. There is no differential depletion on dust between the H I and H II region. Using sulfur as a metallicity tracer, we calculate a metallicity of 1/46 Z(solar) (vs. 1/31 Z(solar) in the H II region). From the study of the C/O, [O/Fe], and N/O abundance ratios, we propose that C, N, O, and Fe are mainly produced in massive stars. We argue that the H I envelope may contain pockets of pristine gas with a metallicity essentially null. Finally, we derive the physical conditions in the H I region by investigating the C II* absorption line. The cooling rate derived from C II* is consistent with collisions with H(sup 0) atoms in the diffuse neutral gas. We calculate the star-formation rate from the CII* cooling rate assuming that photoelectric effect on dust is the dominant gas heating mechanism. Our determination is in good agreement with the values in the literature if we assume a low dust-to-gas ratio (approx 2000 times lower than the Milky Way value).

Lebouteiller, V.; Heap, S.; Hubeny, I.; Kunth, D.

2013-01-01

434

The balance model of oxygen enrichment of atmospheric air  

NASA Astrophysics Data System (ADS)

The study of turnover of carbon and oxygen is an important line of scientific investigation. This line takes on special significance in conditions of soil degradation, which leads to the excess content of carbon dioxide and, as result, decrease of oxygen in the atmosphere. The aim of this article is a statement the balance model of oxygen enrichment of atmospheric air (ratio O/C) depending on consumption and assimilation by plants of dissolved organic matter (DOM) and the value of the oxidation-reduction potential (Eh). Basis of model was the following: green vascular plants are facultative heterotrophic organisms with symbiotic digestion and nutrition. According to the trophology viewpoint, the plant consumption of organic compounds broadens greatly a notion about the plant nutrition and ways of its regulation. In particular, beside the main known cycle of carbon: plant - litter - humus - carbon dioxide - plant, there is the second carbon cycle (turnover of organic compounds): plant - litter - humus - DOM - plant. The biogeochemical meaning of consumption of organic compounds by plants is that plants build the structural and functional blocks of biological macromolecules in their bodies. It provides receiving of a certain "energy payoff" by plants, which leads to increase of plant biomass by both an inclusion of allochthonous organic molecules in plant tissues, and positive effect of organic compounds on plant metabolic processes. One more of powerful ecological consequence of a heterotrophic nutrition of green plants is oxygen enrichment of atmospheric air. As the organic molecules in the second biological cycle of carbon are built in plants without considerable chemical change, the atmospheric air is enriched on that amount of oxygen, which would be required on oxidation of the organic molecules absorbed by plants, in result. It was accepted that: plant-soil system was climax, the plant community was grassy, initial contents of carbon in phytomass was accepted as 1, annually from 60 to 100 % of the plant litter could arrive to the soil; coefficients of humification of both plant litter and DOM were 0.1 (10 %); DOM is formed as a result of hydrolytic destruction of plant litter, newly formed humic substances (HS) and humus; coefficient of possible absorption of DOM by plants - 0.1 (10 %); it was considered that all organic compounds affiliated into DOM had positive physiological effect on green plants; it was accepted that 1 % DOM absorbed by plants increases phytomass on 10 % (for example, at the expense of photosynthesis acceleration); Eh value was changed from 300 to 800 mV; depending on Eh (i) the coefficient of plant litter oxidation was in the range from 0.75 (75 %) to 0.8 (90 %), coefficient of oxidation of DOM and newly formed HS - from 0.85 (85 %) to 0.9 (90 %), and coefficient of humus oxidation from 0 (0 %) to 0.05 (5 %), and (ii) coefficient of hydrolytic destruction of plant litter and newly formed HS was in the range from 0.12 (12 %) to 0.07 (7 %), and coefficient of humus hydrolytic destruction from 0,05 (5 %) to 0 (0 %), accordingly; all dependences were quasilinear. The following conclusions have been made based on the modeling: (i) both phytomass and oxygen content in atmospheric air were increased with increase of DOM part absorbed by green vascular plants; (ii) the abundance of humus was increased with increase of DOM consumption by green plant (on 5 % at all Eh values) too; (iii) the increase of Eh with 300 to 800 mV led to reduction of oxygen in atmospheric air and to quadruple decrease of the abundance of humus.

Popov, Alexander

2013-04-01

435

From enrichment to equity: comments on diversifying the K-12 medical school pipeline.  

PubMed Central

Educating a physician workforce that reflects the increasing racial and ethnic diversity of our nation is an ongoing challenge of urgent concern. Many medical school kindergarten through 1 2th grade (K-12) pipeline programs focus on "enriching" underrepresented minority (URM) students using strategies to change or "improve" individual students. This discussion raises concerns over longstanding racial and ethnic inequities in America's public schools that, in part, result in the predictable and systematic underachievement of URM students. These insidious processes can disqualify URM students from successful participation in the medical school pipeline at its earliest stages. The paper also discusses the cultural challenges URM students often face in aspiring to exceptional academic achievement within America's schools. Finally, this paper highlights the need for illustrative examples of medical school-public school partnerships that pursue an agenda of equity to balance the current downstream focus on the enrichment of individual students. PMID:12152930

Murray-García, Jann L.; García, Jorge A.

2002-01-01

436

Semantic enrichment of building and construction knowledge sources using a domain ontology for classification  

NASA Astrophysics Data System (ADS)

The paper introduces a new conceptual framework for representation of knowledge sources (whether they are web pages or documents), where each knowledge source is semantically represented (within its domain of use) by a Semantic Vector (SV), which is enriched using the classical vector space model approach extended with ontological support, employing ontology concepts and their relations in the enrichment process. The test domain for the assessment of the approach is the Building and Construction, using an appropriate available Ontology. Preliminary results were collected using a clustering algorithm for document classification where documents were assigned into a pre-defined set of categories. Such results indicate that the proposed approach does improve the precision and recall of classifications.

Costa, Ruben; Lima, Celson; Sarraipa, João; Jardim-Gonçalves, Ricardo

2013-10-01

437

Experimental evidence of nitrogen control on pCO(2) in phosphorus-enriched humic and clear coastal lagoon waters.  

PubMed

Natural and human-induced controls on carbon dioxide (CO(2)) in tropical waters may be very dynamic (over time and among or within ecosystems) considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N) and phosphorus (P) inputs into coastal lagoons waters may be a relevant component of the carbon cycle, showing controls on partial pressure of CO(2) (pCO(2)) that are still poorly understood. Here we assessed the strength of N control on pCO(2) in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients) and three levels of N additions coupled to P enrichments. In humic coastal lagoons waters, a persistent CO(2) supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24- to 4-fold the atmospheric equilibrium value. However, both humic and clear coastal lagoons waters only showed significant decreases in pCO(2) in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoons water microcosms showed a shift from CO(2) sources to CO(2) sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO(2) substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO(2) even in P-enriched coastal lagoons waters, thereby being important drivers on CO(2) outgassing from inland waters. PMID:23390422

Peixoto, Roberta B; Marotta, Humberto; Enrich-Prast, Alex

2013-01-01

438

Experimental evidence of nitrogen control on pCO2 in phosphorus-enriched humic and clear coastal lagoon waters  

PubMed Central

Natural and human-induced controls on carbon dioxide (CO2) in tropical waters may be very dynamic (over time and among or within ecosystems) considering the potential role of warmer temperatures intensifying metabolic responses and playing a direct role on the balance between photosynthesis and respiration. The high magnitude of biological processes at low latitudes following eutrophication by nitrogen (N) and phosphorus (P) inputs into coastal lagoons waters may be a relevant component of the carbon cycle, showing controls on partial pressure of CO2 (pCO2) that are still poorly understood. Here we assessed the strength of N control on pCO2 in P-enriched humic and clear coastal lagoons waters, using four experimental treatments in microcosms: control (no additional nutrients) and three levels of N additions coupled to P enrichments. In humic coastal lagoons waters, a persistent CO2 supersaturation was reported in controls and all nutrient-enriched treatments, ranging from 24- to 4-fold the atmospheric equilibrium value. However, both humic and clear coastal lagoons waters only showed significant decreases in pCO2 in relation to the controlled microcosms in the two treatments with higher N addition levels. Additionally, clear coastal lagoons water microcosms showed a shift from CO2 sources to CO2 sinks, in relation to the atmosphere. Only in the two more N-enriched treatments did pCO2 substantially decrease, from 650 µatm in controls and less N-enriched treatments to 10 µatm in more N-enriched microcosms. Humic substrates and N inputs can modulate pCO2 even in P-enriched coastal lagoons waters, thereby being important drivers on CO2 outgassing from inland waters. PMID:23390422

Peixoto, Roberta B.; Marotta, Humberto; Enrich-Prast, Alex

2013-01-01

439

Helium recovery process  

Microsoft Academic Search

In a process for the recovery of helium from natural gas by liquefaction of hydrocarbons and separation of gaseous helium, the gaseous mixture containing helium, carbon dioxide, nitrogen, and methane is cooled to separate a liquid fraction containing dissolved helium and a helium-enriched gaseous fraction. The helium is stripped from the liquid fraction into an overhead gaseous fraction which is

D. B. Crawford; M. Karafian

1967-01-01

440

Enriching low-order finite elements by interpolation covers  

E-print Network

This dissertation presents an enriched finite element procedure based on the use of interpolation cover functions for low-order finite elements, namely, the 3-node triangular and 4- node tetrahedral elements. The standard ...

Kim, Jae Hyung, Ph. D. Massachusetts Institute of Technology

2013-01-01