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1

Decommissioning of an enriched uranium processing facility  

Microsoft Academic Search

The Los Alamos National Laboratory TA-21, Buildings 3 and 4 South decontamination and decommissioning (D&D) project began remediation on September 20, 1993. The project is one of the largest U.S. Department of Energy-sponsored D&D projects currently under way. The project involves the decontamination, dismantlement, and demolition of two enriched-uranium processing buildings, which is an area of â¼10000 ft². The enriched-uranium

Stout

1994-01-01

2

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

3

The chromatographic uranium enrichment process by Asahi chemical  

Microsoft Academic Search

Novel uranium absorbents and catalysts for accelerating the electronexchange reaction between uranous and uranyl ions, as well as other technical developments since 1972, have drastically improved the basis of the chemical exchange process. A unit of a few packed towers is the basic enrichment module for the Asahi Chemical Enrichment Process. A stationary concentration profile of uranium isotopes is formed

S. Maomi; T. Hunihiko; M. Tetsuya

1982-01-01

4

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

5

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

6

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

7

Process for preparing a chemical compound enriched in isotope content  

DOEpatents

A process to prepare a chemical enriched in isotope content which includes: (a) A chemical exchange reaction between a first and second compound which yields an isotopically enriched first compound and an isotopically depleted second compound; (b) the removal of a portion of the first compound as product and the removal of a portion of the second compound as spent material; (c) 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; (d) 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.

Michaels, Edward D. (Spring Valley, OH)

1982-01-01

8

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

Federal Register 2010, 2011, 2012, 2013

...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

9

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

10

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

11

U Mineral Hosts and Enrichment Processes in Altered Oceanic Crust  

NASA Astrophysics Data System (ADS)

The U-Pb-Th isotopic system is a primary tool for understanding mantle and continental evolution and for quantifying the flow of mass and heat through the Earth's reservoirs. One of the major sites of U-Pb-Th fractionation is the oceanic crust, which is a sink for seawater U. For example, the upper, oxidized oceanic crust (U ~0.4ppm) may be as much as 4x enriched over pristine igneous values (U ~0.09ppm) with a minor net change in Pb and Th. Little, however, is understood about the mechanisms controlling uranium enrichment, its mineral hosts, or the timing of the process. We have used laser ablation inductively coupled mass spectrometry (LA-ICP-MS) and electron microprobe data to study the distribution of U in the oldest sampled crust in the Pacific, Jurassic mid-ocean ridge basalts (MORB) from ODP Site 801C (1000 km seaward of the Mariana trench), formed at fast spreading rates. Seventeen thin sections, 8 with the highest whole rock U content (HUC) (0.61-1.7ppm) and 9 with low U content (LUC) (U <0.4ppm) were analyzed in detail. Twelve of the thin sections contain various types of carbonates (veins, vugs, vesicles, and inter-flow material) in a variety of crystal morphologies (radial, inclusion-rich, and sparry). A 50-micron laser beam was rastered across various alteration zones, such as halos, veins, and the surrounding host to provide in-situ multi-element analysis (U, Th, Pb, REE, alkalis, etc). HUC are exclusively associated with low-Mg calcites (< 1wt% Mg), whereas LUC are typically associated with high-Mg calcites (10-20 wt% Mg). U also correlates positively with Sr and negatively with total rare earth element (REE) concentration. High U carbonates inherit the seawater REE pattern with both HREE and LREE enrichment, whereas LUC inherit the LREE depletion of the MORB host. Thus, there appear to be distinct generations of fluids that precipitate carbonate; those with the high Sr and low REE of seawater tend to precipitate U-rich calcites (up to 4.5 ppm U). Four thin sections containing Fe-oxide veins ± celadonite and carbonates were also analyzed. Initial analysis suggests high U ( ~1.8ppm) is associated with Fe-oxides, halos immediately surrounding the mixed Fe-oxide veins, or redox fronts further into the basaltic hosts (up to 0.5mm from the oxide veins). Thus, U in altered MORB is associated with three types of alteration phases: 1) carbonate veins, 2) halos surrounding mixed Fe-oxide veins, and 3) Fe-oxide phases. Of the excess U in the upper 500 m at 801C, roughly 2/3 is carbonate-hosted. Given the variety of hosts, we might predict variable release of U into the mantle as these different phases breakdown in the subduction zone. These results also point to a need for more data on carbonate and oxide fluid partitioning at high pressure.

Farr, L. C.; Plank, T.; Kelley, K.; Alt, J. C.

2001-12-01

12

Efficiency evaluation of oxygen enrichment in energy conversion processes  

Microsoft Academic Search

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

Bomelburg

1983-01-01

13

Robotic Enrichment Processing of Roche 454 Titanium Emlusion PCR at the DOE Joint Genome Institute  

SciTech Connect

Enrichment of emulsion PCR product is the most laborious and pipette-intensive step in the 454 Titanium process, posing the biggest obstacle for production-oriented scale up. The Joint Genome Institute has developed a pair of custom-made robots based on the Microlab Star liquid handling deck manufactured by Hamilton to mediate the complexity and ergonomic demands of the 454 enrichment process. The robot includes a custom built centrifuge, magnetic deck positions, as well as heating and cooling elements. At present processing eight emulsion cup samples in a single 2.5 hour run, these robots are capable of processing up to 24 emulsion cup samples. Sample emulsions are broken using the standard 454 breaking process and transferred from a pair of 50ml conical tubes to a single 2ml tube and loaded on the robot. The robot performs the enrichment protocol and produces beads in 2ml tubes ready for counting. The robot follows the Roche 454 enrichment protocol with slight exceptions to the manner in which it resuspends beads via pipette mixing rather than vortexing and a set number of null bead removal washes. The robotic process is broken down in similar discrete steps: First Melt and Neutralization, Enrichment Primer Annealing, Enrichment Bead Incubation, Null Bead Removal, Second Melt and Neutralization and Sequencing Primer Annealing. Data indicating our improvements in enrichment efficiency and total number of bases per run will also be shown.

Hamilton, Matthew; Wilson, Steven; Bauer, Diane; Miller, Don; Duffy-Wei, Kecia; Hammon, Nancy; Lucas, Susan; Pollard, Martin; Cheng, Jan-Fang

2010-05-28

14

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

15

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

16

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

17

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

18

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

19

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

20

Assessment of the interstellar processes leading to deuterium enrichment in meteoritic organics  

E-print Network

Assessment of the interstellar processes leading to deuterium enrichment in meteoritic organics@mail.arc.nasa.gov (Received 2001 February 13; accepted in revised form 2001 May 4) Meteoritics & Planetary Science 36, 1117­1133 (2001) Available online at http://www.uark.edu/meteor © Meteoritical Society, 2001. Printed in USA. 1117

21

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

22

Process for protein enrichment of cassava by solid substrate fermentation in rural conditions  

SciTech Connect

An artisanal static process for protein enrichment of cassava by solid-state fermentation, developed in laboratory and tested on pilot units in Burundi (Central Africa), provides enriched cassava containing 10.7% of dry matter protein versus 1% before fermentation. Cassava chips, processed into granules of 2-4-mm diameter, are moistened (40% water content) and steamed. After cooling to 40 degrees C, cassava is mixed with a nutritive solution containing the inoculum (Rhizopus oryzae, strain MUCL 28627) and providing the following per 100 g dry matter: 3.4 g urea, 1.5 g KH/sub 2/PO/sub 4/, O.8 g MgSO/sub 4/.7H/sub 2/O, and 22.7 g citric acid. For the fermentation, cassava, with circa 60% moisture content, is spread in a thin layer (2-3 cm thick) on perforated trays and slid into an aerated humidified enclosure. The incubation lasts more or less 65 hours. The production of protein enriched cassava is 3.26 kg dry matter/square m tray. The effects of the variation of the nutritive solution composition and the inoculum conservation period on the protein production are equally discussed. (Refs. 37).

Daubresse, P.; Ntibashirwa, S.; Gheysen, A.; Meyer, J.A.

1987-06-01

23

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

24

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

25

The s-Process Enrichment of the Globular Clusters M4 and M22  

NASA Astrophysics Data System (ADS)

We investigate the enrichment in elements produced by the slow neutron-capture process (s-process) in the globular clusters M4 (NGC 6121) and M22 (NGC 6656). Stars in M4 have homogeneous abundances of Fe and neutron-capture elements, but the entire cluster is enhanced in s-process elements (Sr, Y, Ba, Pb) relative to other clusters with a similar metallicity. In M22, two stellar groups exhibit different abundances of Fe and s-process elements. By subtracting the mean abundances of s-poor from s-rich stars, we derive s-process residuals or empirical s-process distributions for M4 and M22. We find that the s-process distribution in M22 is more weighted toward the heavy s-peak (Ba, La, Ce) and Pb than M4, which has been enriched mostly with light s-peak elements (Sr, Y, Zr). We construct simple chemical evolution models using yields from massive star models that include rotation, which dramatically increases s-process production at low metallicity. We show that our massive star models with rotation rates of up to 50% of the critical (break-up) velocity and changes to the preferred 17O(?, ?)21Ne rate produce insufficient heavy s-elements and Pb to match the empirical distributions. For models that incorporate asymptotic giant branch yields, we find that intermediate-mass yields (with a 22Ne neutron source) alone do not reproduce the light-to-heavy s-element ratios for M4 and M22, and that a small contribution from models with a 13C pocket is required. With our assumption that 13C pockets form for initial masses below a transition range between 3.0 and 3.5 M ?, we match the light-to-heavy s-element ratio in the s-process residual of M22 and predict a minimum enrichment timescale of between 240 and 360 Myr. Our predicted value is consistent with the 300 Myr upper limit age difference between the two groups derived from isochrone fitting.

Shingles, Luke J.; Karakas, Amanda I.; Hirschi, Raphael; Fishlock, Cherie K.; Yong, David; Da Costa, Gary S.; Marino, Anna F.

2014-11-01

26

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

27

Presolar Graphite from AGB Stars: Microstructure and s-Process Enrichment  

NASA Astrophysics Data System (ADS)

Correlated transmission electron microscopy and secondary ion mass spectrometry with submicron spatial resolution (NanoSIMS) investigations of the same presolar graphites spherules from the Murchison meteorite were conducted, to link the isotopic anomalies with the mineralogy and chemical composition of the graphite and its internal grains. Refractory carbide grains (especially titanium carbide) are commonly found within the graphite spherules, and most have significant concentrations of Zr, Mo, and Ru in solid solution, elements primarily produced by s-process nucleosynthesis. The effect of chemical fractionation on the Mo/Ti ratio in these carbides is limited, and therefore from this ratio one can infer the degree of s-process enrichment in the gas from which the graphite condensed. The resulting s-process enrichments within carbides are large (~200 times solar on average), showing that most of the carbide-containing graphites formed in the mass outflows of asymptotic giant branch (AGB) stars. NanoSIMS measurements of these graphites also show isotopically light carbon (mostly in the 100<12C/13C<400 range). The enrichment of these presolar graphites in both s-process elements and 12C considerably exceeds that astronomically observed around carbon stars. However, a natural correlation exists between 12C and s-process elements, as both form in the He intershell region of thermally pulsing AGB stars and are dredged up together to the surface. Their observation together suggests that these graphites may have formed in chemically and isotopically inhomogeneous regions around AGB stars, such as high-density knots or jets. As shown in the companion paper, a gas density exceeding that expected for smooth mass outflows is required for graphite of the observed size to condense at all in circumstellar environments, and the spatially inhomogeneous, high-density regions from which they condense may also be incompletely mixed with the surrounding gas. We have greatly expanded the available data set of presolar graphites (N=847) and characterized them by their morphology (onion type and cauliflower type). This effort has also revealed two new, rare presolar phases (iron carbide and metallic osmium). Due to the peculiar gas composition needed to form these rare presolar grain types, the graphites containing them are more likely to originate in supernova outflows.

Croat, Thomas K.; Stadermann, Frank J.; Bernatowicz, Thomas J.

2005-10-01

28

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

29

Modification of targets and processes for conversion of ⁹⁹Mo production from high- to low-enriched uranium  

Microsoft Academic Search

As part of the U.S. nonproliferation effort, we are investigating the conversion of the production of fission-product ⁹⁹Mo from use of high-enriched uranium (HEU) to low-enriched uranium (LEU). Successful conversion from HEU to LEU (<20% ²³⁵U) requires an irradiation target that contains 5 times more uranium but minimizes changes to target geometry and processing. The LEU target being developed uses

G. F. Vandegrift; C. Conner; G. L. Hofman; R. A. Leonard; A. Mutalib; J. Sedlet; D. E. Walker; T. C. Wiencek; J. L. Snelgrove

2000-01-01

30

Using Process Load Cell Information for IAEA Safeguards at Enrichment Plants  

Microsoft Academic Search

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

Mark D Laughter; J Michael Whitaker; John Howell

2010-01-01

31

The History of R-Process Enrichment in the Milky Way  

E-print Network

We investigate the production sites and the enrichment history of r-process elements in the Galaxy, as traced by the [Eu/Fe] ratio, using the high resolution, cosmological zoom-in simulation `Eris'. At z=0, Eris represents a close analog to the Milky Way, making it the ideal laboratory to understand the chemical evolution of our Galaxy. Eris formally traces the production of $\\alpha$-capture and Fe-peak elements due to Type Ia and Type II supernovae. We include in post-processing the production of r-process elements from either Type II supernovae or compact binary mergers. Unlike previous studies, we find that the nucleosynthetic products from compact binary mergers can be incorporated into stars of very low metallicity and at early times, even with a minimum delay time of 100 Myr. This conclusion is relatively insensitive to modest variations in the merger rate and delay time distribution. By implementing a first-order prescription for metal-mixing, we can further improve the agreement between our model and ...

Shen, Sijing; Ramirez-Ruiz, Enrico; Madau, Piero; Mayer, Lucio; Guedes, Javiera

2014-01-01

32

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

33

MUSIC: Identification of Enriched Regions in ChIP-Seq Experiments using a Mappability-Corrected Multiscale Signal Processing Framework.  

PubMed

We present MUSIC, a signal processing approach for identification of enriched regions in ChIP-Seq data, available at music.gersteinlab.org. MUSIC first filters the ChIP-Seq read-depth signal for systematic noise from non-uniform mappability, which fragments enriched regions. Then it performs a multiscale decomposition, using median filtering, identifying enriched regions at multiple length scales. This is useful given the wide range of scales probed in ChIP-Seq assays. MUSIC performs favorably in terms of accuracy and reproducibility compared with other methods. In particular, analysis of RNA Polymerase II data reveals a clear distinction between the stalled and elongating forms of the polymerase. PMID:25292436

Harmanci, Arif; Rozowsky, Joel; Gerstein, Mark

2014-10-01

34

Massive Organic Matter Fall Processing and Organic Enrichment in Deep Sea Sediments: the Role of Fall Type  

NASA Astrophysics Data System (ADS)

Resource-limited deep-sea sedimentary settings are occasionally punctuated with massive organic matter (MOM) falls, such as fish and marine mammal carcasses, macrophytes and wood. In the case of whale falls, previous studies have shown that sharp gradients in microbial activity exist within a few meters of these falls. These sites are characterized by intense sulfate reduction and sulfide generation, which are commonly attributed to sedimentary organic enrichment from MOM, and in part support extensive chemosynthetic communities that rely on endosymbiotic oxidation of this sulfide for energy. Enrichment is brought about by the fragmentation and dissemination activities of deep-sea megafauna: scavengers in the case of carcasses and macrophytes, and wood borers in the case of wood.Differences in MOM fall composition and structure and the subsequent megafaunal processing raise questions concerning the patterns of organic enrichment around these falls and how these patterns vary with fall type. We present an extensive data set of surface sediment organic carbon and nitrogen content at whale, kelp and wood falls of various ages in the California Borderland Basins region. Evidence for organic enrichment around whale falls is lacking, corroborating previous findings. However, distinctly low C:N ratios in surface sediments adjacent to whale falls suggest more complex processing of MOM in this zone. This pattern persists regardless of whale fall age. On the contrary, evidence for organic enrichment around kelp and wood falls abounds. Organic carbon and nitrogen content values adjacent to 3 month-old kelp falls are 25-50 % higher than those 1 m away from the falls and traces of this signal persist for at least 3 more months. In the case of wood falls, 6 month-old falls do not show any significant traces of enrichment, but 3 years after the fall event organic carbon content adjacent to the falls increases by 2-5 times that of background. C:N ratios concomitantly increase to startling levels of 80-100. Comparison of falls of different ages but similar masses reveals that kelp falls result in rapid (<3 months) enrichment peaks, while wood falls only generate significant signals on the order of years. Comparison of organic enrichment patterns with pore water sulfide distributions suggests a role of MOM type or quality in stimulating increases in sedimentary organic matter decomposition rates.

Hannides, A. K.; Smith, C. R.; Baco-Taylor, A. R.

2005-12-01

35

Gene-ontology enrichment analysis in two independent family-based samples highlights biologically plausible processes for autism spectrum disorders  

PubMed Central

Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biological pathways in the aetiology of autism. However, despite the strong influence of genetic factors, association studies have yet to identify statistically robust, replicated major effect genes or SNPs. We apply the principle of the SNP ratio test methodology described by O'Dushlaine et al to over 2100 families from the Autism Genome Project (AGP). Using a two-stage design we examine association enrichment in 5955 unique gene-ontology classifications across four groupings based on two phenotypic and two ancestral classifications. Based on estimates from simulation we identify excess of association enrichment across all analyses. We observe enrichment in association for sets of genes involved in diverse biological processes, including pyruvate metabolism, transcription factor activation, cell-signalling and cell-cycle regulation. Both genes and processes that show enrichment have previously been examined in autistic disorders and offer biologically plausibility to these findings. PMID:21522181

Anney, Richard J L; Kenny, Elaine M; O'Dushlaine, Colm; Yaspan, Brian L; Parkhomenka, Elena; Buxbaum, Joseph D; Sutcliffe, James; Gill, Michael; Gallagher, Louise; Bailey§, Anthony J; Fernandez, Bridget A; Szatmari§, Peter; Scherer§, Stephen W; Patterson§, Andrew; Marshall, Christian R; Pinto, Dalila; Vincent, John B; Fombonne, Eric; Betancur§, Catalina; Delorme, Richard; Leboyer, Marion; Bourgeron, Thomas; Mantoulan, Carine; Roge, Bernadette; Tauber, Maïté; Freitag§, Christine M; Poustka, Fritz; Duketis, Eftichia; Klauck§, Sabine M; Poustka, Annemarie; Papanikolaou, Katerina; Tsiantis, John; Gallagher§, Louise; Gill§, Michael; Anney, Richard; Bolshakova, Nadia; Brennan, Sean; Hughes, Gillian; McGrath, Jane; Merikangas, Alison; Ennis§, Sean; Green, Andrew; Casey, Jillian P; Conroy, Judith M; Regan, Regina; Shah, Naisha; Maestrini§, Elena; Bacchelli, Elena; Minopoli, Fiorella; Stoppioni, Vera; Battaglia§, Agatino; Igliozzi, Roberta; Parrini, Barbara; Tancredi, Raffaella; Oliveira§, Guiomar; Almeida, Joana; Duque, Frederico; Vicente§, Astrid; Correia, Catarina; Magalhaes, Tiago R; Gillberg, Christopher; Nygren, Gudrun; Jonge, Maretha de; Van Engeland, Herman; Vorstman, Jacob AS; Wittemeyer, Kerstin; Baird, Gillian; Bolton, Patrick F; Rutter, Michael L; Green, Jonathan; Lamb, Janine A; Pickles, Andrew; Parr, Jeremy R; Couteur, Ann Le; Berney, Tom; McConachie, Helen; Wallace, Simon; Coutanche, Marc; Foley, Suzanne; White, Kathy; Monaco§, Anthony P; Holt, Richard; Farrar, Penny; Pagnamenta, Alistair T; Mirza, Ghazala K; Ragoussis, Jiannis; Sousa, Inês; Sykes, Nuala; Wing, Kirsty; Hallmayer§, Joachim; Cantor§, Rita M; Nelson, Stanley F; Geschwind§, Daniel H; Abrahams, Brett S; Volkmar, Fred; Pericak-Vance§, Margaret A; Cuccaro, Michael L; Gilbert, John; Cook§, Edwin H; Guter, Stephen J; Jacob, Suma; Nurnberger Jr§, John I; McDougle, Christopher J; Posey, David J; Lord, Catherine; Corsello, Christina; Hus, Vanessa; Buxbaum§, Joseph D; Kolevzon, Alexander; Soorya, Latha; Parkhomenko, Elena; Leventhal, Bennett L; Dawson, Geraldine; Vieland§, Veronica J; Hakonarson§, Hakon; Glessner, Joseph T; Kim, Cecilia; Wang, Kai; Schellenberg§, Gerard D; Devlin§, Bernie; Klei, Lamburtus; Minshew, Nancy; Sutcliffe§, James S; Haines§, Jonathan L; Lund, Sabata C; Thomson, Susanne; Yaspan, Brian L; Coon§, Hilary; Miller, Judith; McMahon, William M; Munson, Jeff; Estes, Annette; Wijsman§, Ellen M; Buxbaum, Joseph D; Sutcliffe, James; Gill, Michael; Gallagher, Louise

2011-01-01

36

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

37

Automatic processing of multilingual medical terminology: applications to thesaurus enrichment and cross-language information retrieval  

Microsoft Academic Search

We present in this article experiments on Multi-Language Information Extraction and Access in the medical domain. Methods for extracting bilingual lexicons from parallel and comparable corpora are described and their use in Multi- Language Information Access is illustrated. Our experiments show that these automatically extracted bilingual lexicons are accurate enough for semi-automatically enriching mono- or bilingual thesauri (such as UMLS),

Hervé Déjean; Éric Gaussier; Jean-michel Renders; Fatiha Sadat

2005-01-01

38

Uranium isotope measurements by quadrupole ICP-MS for process monitoring of enrichment  

SciTech Connect

Historically, uranium isotopic ratio measurements in the nuclear industry have been performed using Thermal Ionization Mass Spectrometry (TIMS); primarily due to the high level of precision that can be achieved. TIMS analysis, however, requires sample purification and intricate sample loading. Quadrupole (low resolution, single detector) inductively coupled plasma--mass spectrometry, Q-ICP-MS, overcomes these disadvantages and is a cost-effective alternative, i.e., in terms of initial capital, maintenance, and operating costs. This paper presents a simple, single standard approach for measuring uranium isotope content in various solid and liquid nuclear materials along with some comparison data of Q-ICP-MS and TIMS. Intensity ratios of {sup 234}U, {sup 235}U, {sup 236}U, and {sup 238}U to total U intensity are produced, providing the enrichment level or percent {sup 235}U. A detailed description of the instrument and data collection parameters are also provided. Optimal precision and accuracy are achieved through the use of a single standard which is closely matched to the enrichment and concentration of the samples. Depending upon the standard chosen, enrichments between depleted and 97% can be quantified. Standard deviations for the major uranium isotopes are typically within 0.02 absolute and at least an order of magnitude lower for the minor U isotope abundances.

Policke, T.A.; Bolin, R.N.; Harris, T.L. [BWX Technologies, Inc., Lynchburg, VA (United States). Engineering and Quality Assurance Dept.

1998-12-31

39

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

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  

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

41

Theorie et pratique de la traduction professionelle: differences de point de vue et enrichissement mutuel (Professional Translation Theory and Practice: Different Perspectives and Mutual Enrichment).  

ERIC Educational Resources Information Center

Argues against the proliferation of translation theories and theoretical courses for translators, stating a preference for an approach that focuses on practical principles. Also discusses issues such as the relationship between lexicology and terminology, the editor's role, and translator's qualifications and responsibilities towards the receptor.…

Darbelnet, Jean

1980-01-01

42

Conceptual Process for the Manufacture of Low-Enriched Uranium/Molybdenum Fuel for the High Flux Isotope Reactor  

SciTech Connect

The U.S. nonproliferation policy 'to minimize, and to the extent possible, eliminate the use of HEU in civil nuclear programs throughout the world' has resulted in the conversion (or scheduled conversion) of many of the U.S. research reactors from high-enriched uranium (HEU) to low-enriched uranium (LEU). A foil fuel appears to offer the best option for using a LEU fuel in the High Flux Isotope Reactor (HFIR) without degrading the performance of the reactor. The purpose of this document is to outline a proposed conceptual fabrication process flow sheet for a new, foil-type, 19.75%-enriched fuel for HFIR. The preparation of the flow sheet allows a better understanding of the costs of infrastructure modifications, operating costs, and implementation schedule issues associated with the fabrication of LEU fuel for HFIR. Preparation of a reference flow sheet is one of the first planning steps needed in the development of a new manufacturing capacity for low enriched fuels for U.S. research and test reactors. The flow sheet can be used to develop a work breakdown structure (WBS), a critical path schedule, and identify development needs. The reference flow sheet presented in this report is specifically for production of LEU foil fuel for the HFIR. The need for an overall reference flow sheet for production of fuel for all High Performance Research Reactors (HPRR) has been identified by the national program office. This report could provide a starting point for the development of such a reference flow sheet for a foil-based fuel for all HPRRs. The reference flow sheet presented is based on processes currently being developed by the national program for the LEU foil fuel when available, processes used historically in the manufacture of other nuclear fuels and materials, and processes used in other manufacturing industries producing a product configuration similar to the form required in manufacturing a foil fuel. The processes in the reference flow sheet are within the bounds of known technology and are adaptable to the high-volume production required to process {approx} 2.5 to 4 tons of U/Mo and produce {approx}16,000 flat plates for U.S. reactors annually ({approx}10,000 of which are needed for HFIR operations). The reference flow sheet is not intended to necessarily represent the best or the most economical way to manufacture a LEU foil fuel for HFIR but simply represents a 'snapshot' in time of technology and is intended to identify the process steps that will likely be required to manufacture a foil fuel. Changes in some of the process steps selected for the reference flow sheet are inevitable; however, no one step or series of steps dominates the overall flow sheet requirements. A result of conceptualizing a reference flow sheet was the identification of the greater number of steps required for a foil process when compared to the dispersion fuel process. Additionally, in most of the foil processing steps, bare uranium must be handled, increasing the complexity of these processing areas relative to current operations. Based on a likely total cost of a few hundred million dollars for a new facility, it is apparent that line item funding will be necessary and could take as much as 8 to 10 years to complete. The infrastructure cost could exceed $100M.

Sease, J.D.; Primm, R.T. III; Miller, J.H.

2007-09-30

43

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

44

A new process for enriching nitrifiers in activated sludge through separate heterotrophic wasting from biofilm carriers.  

PubMed

A new process, the biofilm-activated sludge innovative nitrification (BASIN) process, consisting of a moving-bed biofilm reactor (MBBR) with separate heterotrophic wasting, followed by an activated-sludge process, has been proposed to reduce the volumetric requirements of the activated-sludge process for nitrification. The basic principle is to remove chemical oxygen demand on the biofilm carriers by heterotrophic organisms and then to waste a portion of the heterotrophic biomass before it can be released into the activated-sludge reactor. By this means, the amount of heterotrophic organisms grown in the activated-sludge reactor is reduced, thereby reducing the volume of that tank needed for nitrification. For nitrification applications, the simplest method for stripping biomass was to use an in-tank technique using high shearing rates with aeration. Bench-scale testing showed sludge yields in the BASIN process were one-half of that in a control activated-sludge process and twice that of a process line with intermediate settling between the MBBR and activated-sludge stage. Critical washout solids retention times for nitrifiers were the same for all three lines, so activated-sludge volumes for the BASIN process could be reduced by 50% compared with the control. Originally conceived process concepts for the BASIN process were confirmed by the experimental work. PMID:11995869

Parker, Denny S; Rusten, Bjørn; Wien, Asgeir; Siljudalen, Jon G

2002-01-01

45

Deammonification process start-up after enrichment of anammox microorganisms from reject water in a moving-bed biofilm reactor.  

PubMed

Deammonification via intermittent aeration in biofilm process for the treatment of sewage sludge digester supernatant (reject water) was started up using two opposite strategies. Two moving-bed biofilm reactors were operated for 2.5 years at 26 (+/- 0.5 degree C with spiked influent(and hence free ammonia (FA)) addition. In the first start-up strategy, an enrichment of anammox biomass was first established, followed by the development of nitrifying biomass in the system (R1). In contrast, the second strategy aimed at the enrichment of anammox organisms into a nitrifying biofilm (R2). The first strategy was most successful, reaching higher maximum total nitrogen (TN) removal rates over a shorter start-up period. For both reactors, increasing FA spiking frequency and increasing effluent concentrations of the anammox intermediate hydrazine correlated to decreasing aerobic nitrate production (nitritation). The bacterial consortium of aerobic and anaerobic ammonium oxidizing bacteria in the bioreactor was determined via denaturing gel gradient electrophoresis, polymerase chain reaction and pyrosequencing. In addition to a shorter start-up with a better TN removal rate, nitrite oxidizing bacteria (Nitrospira) were outcompeted by spiked ammonium feeding from R1. PMID:24617068

Zekker, Ivar; Rikmann, Ergo; Tenno, Toomas; Kroon, Kristel; Vabamäe, Priit; Salo, Erik; Loorits, Liis; Rubin, Sergio S C dC; Vlaeminck, Siegfried E; Tenno, Taavo

2013-01-01

46

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

47

Enrichment of the metallic components from waste printed circuit boards by a mechanical separation process using a stamp mill  

SciTech Connect

Printed circuit boards incorporated in most electrical and electronic equipment contain valuable metals such as Cu, Ni, Au, Ag, Pd, Fe, Sn, and Pb. In order to employ a hydrometallurgical route for the recycling of valuable metals from printed circuit boards, a mechanical pre-treatment step is needed. In this study, the metallic components from waste printed circuit boards have been enriched using a mechanical separation process. Waste printed circuit boards shredded to <10 mm were milled using a stamp mill to liberate the various metallic components, and then the milled printed circuit boards were classified into fractions of <0.6, 0.6-1.2, 1.2-2.5, 2.5-5.0, and >5.0 mm. The fractions of milled printed circuit boards of size <5.0 mm were separated into a light fraction of mostly non-metallic components and a heavy fraction of the metallic components by gravity separation using a zig-zag classifier. The >5.0 mm fraction and the heavy fraction were subjected to two-step magnetic separation. Through the first magnetic separation at 700 Gauss, 83% of the nickel and iron, based on the whole printed circuit boards, was recovered in the magnetic fraction, and 92% of the copper was recovered in the non-magnetic fraction. The cumulative recovery of nickel-iron concentrate was increased by a second magnetic separation at 3000 Gauss, but the grade of the concentrate decreased remarkably from 76% to 56%. The cumulative recovery of copper concentrate decreased, but the grade increased slightly from 71.6% to 75.4%. This study has demonstrated the feasibility of the mechanical separation process consisting of milling/size classification/gravity separation/two-step magnetic separation for enriching metallic components such as Cu, Ni, Al, and Fe from waste printed circuit boards.

Yoo, Jae-Min; Jeong, Jinki; Yoo, Kyoungkeun [Minerals and Materials Processing Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 30 Gajeong-dong, Yuseong-gu, Daejeon 305-350 (Korea, Republic of); Lee, Jae-chun [Minerals and Materials Processing Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 30 Gajeong-dong, Yuseong-gu, Daejeon 305-350 (Korea, Republic of)], E-mail: jclee@kigam.re.kr; Kim, Wonbaek [Minerals and Materials Processing Division, Korea Institute of Geoscience and Mineral Resources (KIGAM), 30 Gajeong-dong, Yuseong-gu, Daejeon 305-350 (Korea, Republic of)

2009-03-15

48

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/L) and low-iodine (b10 g/L) groundwater regions that frequently result in iodine excess or deficien- cy

Zhan, Hongbin

49

Geochemical diversity in S processes mediated by culture-adapted and environmental-enrichments of Acidithiobacillus spp.  

NASA Astrophysics Data System (ADS)

Coupled S speciation and acid generation resulting from S processing associated with five different microbial treatments, all primarily Acidithiobacillus spp. (i.e. autotrophic S-oxidizers) were evaluated in batch laboratory experiments. Microbial treatments included two culture-adapted strains, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, their consortia and two environmental enrichments from a mine tailings lake that were determined to be >95% Acidithiobacillus spp., by whole-cell fluorescent hybridization. Using batch experiments simulating acidic mine waters with no carbon amendments, acid generation, and S speciation associated with the oxidation of three S substrates (thiosulfate, tetrathionate, and elemental S) were evaluated. Aseptic controls showed no observable pH decrease over the experimental time course (1 month) for all three S compounds examined. In contrast, pH decreased in all microbial treatments from starting pH values of 4 to 2 or less for all three S substrates. Results show a non-linear relationship between the pH dynamics of the batch cultures and their corresponding sulfate concentrations, and indicate how known microbial S processing pathways have opposite impacts, ultimately on pH dynamics. Associated geochemical modeling indicated negligible abiogenic processes contributing to the observed results, indicating strong microbial control of acid generation extending over pH ranges from 4 to less than 2. However, the observed acid generation rates and associated S speciation were both microbial treatment and substrate-specific. Results reveal a number of novel insights regarding microbial catalysis of S oxidation: (1) metabolic diversity in S processing, as evidenced by the observed geochemical signatures in S chemical speciation and rates of acid generation amongst phylogenetically similar organisms (to the genus level); (2) consortial impacts differ from those of individual strain members; (3) environmental enrichments of Acidithiobacillus spp. catalyze different S reaction arrays than pure strain Acidithiobacillus spp.; and (4) microbial catalysis of S reactions involves significant disproportionation tied to substantial H + consumption, with the formation of as yet, poorly characterized intermediate S species, most likely polythionates and polysulfane monosulfonic acids that are thought to be involved in microbial S storage mechanisms.

Bernier, Luc; Warren, Lesley A.

2007-12-01

50

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

51

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

52

PRESOLAR GRAPHITE FROM AGB STARS: MICROSTRUCTURE AND s-PROCESS ENRICHMENT Thomas K. Croat, Frank J. Stadermann, and Thomas J. Bernatowicz  

E-print Network

2005 April 12 ABSTRACT Correlated transmission electron microscopy and secondary ion mass spectrometry the degree of s-process enrichment in the gas from which the graphite condensed. The resulting s and isotopically inhomogeneous regions around AGB stars, such as high-density knots or jets. As shown

53

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

54

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

55

Candidate processes for diluting the ²³⁵U isotope in weapons-capable highly enriched uranium  

Microsoft Academic Search

The United States Department of Energy (DOE) is evaluating options for rendering its surplus inventories of highly enriched uranium (HEU) incapable of being used to produce nuclear weapons. Weapons-capable HEU was earlier produced by enriching uranium in the fissile ²³⁵U isotope from its natural occurring 0.71 percent isotopic concentration to at least 20 percent isotopic concentration. Now, by diluting its

Snider

1996-01-01

56

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

57

Periphyton response to long-term nutrient enrichment in a shaded headwater stream  

E-print Network

un contenu plus élevé de chlorophylle par cellule, car le biovolume total des algues ne change pas) sont aussi maximaux dans les conditions d'enrichissement. Les peuplements d'algues sont dominés par les'enrichissement. Bien que les nutriments stimulent les taux de croissance des algues, les effets à long terme de l

Rosemond, Amy Daum

58

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

59

In-Situ Measurements of Low Enrichment Uranium Holdup Process Gas Piping at K-25 - Paper for Waste Management Symposia 2010 East Tennessee Technology Park Oak Ridge, Tennessee  

SciTech Connect

This document is the final version of a paper submitted to the Waste Management Symposia, Phoenix, 2010, abstract BJC/OR-3280. The primary document from which this paper was condensed is In-Situ Measurement of Low Enrichment Uranium Holdup in Process Gas Piping at K-25 Using NaI/HMS4 Gamma Detection Systems, BJC/OR-3355. This work explores the sufficiency and limitations of the Holdup Measurement System 4 (HJVIS4) software algorithms applied to measurements of low enriched uranium holdup in gaseous diffusion process gas piping. HMS4 has been used extensively during the decommissioning and demolition project of the K-25 building for U-235 holdup quantification. The HMS4 software is an integral part of one of the primary nondestructive assay (NDA) systems which was successfully tested and qualified for holdup deposit quantification in the process gas piping of the K-25 building. The initial qualification focused on the measurement of highly enriched UO{sub 2}F{sub 2} deposits. The purpose of this work was to determine if that qualification could be extended to include the quantification of holdup in UO{sub 2}F{sub 2} deposits of lower enrichment. Sample field data are presented to provide evidence in support of the theoretical foundation. The HMS4 algorithms were investigated in detail and found to sufficiently compensate for UO{sub 2}F{sub 2} source self-attenuation effects, over the range of expected enrichment (4-40%), in the North and East Wings of the K-25 building. The limitations of the HMS4 algorithms were explored for a described set of conditions with respect to area source measurements of low enriched UO{sub 2}F{sub 2} deposits when used in conjunction with a 1 inch by 1/2 inch sodium iodide (NaI) scintillation detector. The theoretical limitations of HMS4, based on the expected conditions in the process gas system of the K-25 building, are related back to the required data quality objectives (DQO) for the NBA measurement system established for the K-25 demolition project. The combined review of the HMS software algorithms and supporting field measurements lead to the conclusion that the majority of process gas pipe measurements are adequately corrected for source self-attenuation using HMS4. While there will be instances where the UO{sub 2}F{sub 2} holdup mass presents an infinitely thick deposit to the NaI-HMS4 system these situations are expected to be infrequent. This work confirms that the HMS4 system can quantify UO{sub 2}F{sub 2} holdup, in its current configuration (deposition, enrichment, and geometry), below the DQO levels for the K-25 building decommissioning and demolition project. For an area measurement of process gas pipe in the K-25 building, if an infinitely thick UO{sub 2}F{sub 2} deposit is identified in the range of enrichment of {approx}4-40%, the holdup quantity exceeds the corresponding DQO established for the K-25 building demolition project.

Rasmussen B.

2010-01-01

60

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

61

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

62

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

63

Results from a "Proof-of-Concept" Demonstration of RF-Based Tracking of UF6 Cylinders during a Processing Operation at a Uranium Enrichment Plant  

SciTech Connect

Approved industry-standard cylinders are used globally for processing, storing, and transporting uranium hexafluoride (UF{sub 6}) at uranium enrichment plants. To ensure that cylinder movements at enrichment facilities occur as declared, the International Atomic Energy Agency (IAEA) must conduct time-consuming periodic physical inspections to validate facility records, cylinder identity, and containment. By using a robust system design that includes the capability for real-time unattended monitoring (of cylinder movements), site-specific rules-based event detection algorithms, and the capability to integrate with other types of monitoring technologies, one can build a system that will improve overall inspector effectiveness. This type of monitoring system can provide timely detection of safeguard events that could be used to ensure more timely and appropriate responses by the IAEA. It also could reduce reliance on facility records and have the additional benefit of enhancing domestic safeguards at the installed facilities. This paper will discuss the installation and evaluation of a radio-frequency- (RF-) based cylinder tracking system that was installed at a United States Enrichment Corporation Centrifuge Facility. This system was installed primarily to evaluate the feasibility of using RF technology at a site and the operational durability of the components under harsh processing conditions. The installation included a basic system that is designed to support layering with other safeguard system technologies and that applies fundamental rules-based event processing methodologies. This paper will discuss the fundamental elements of the system design, the results from this site installation, and future efforts needed to make this technology ready for IAEA consideration.

Pickett, Chris A [ORNL] [ORNL; Kovacic, Donald N [ORNL] [ORNL; Whitaker, J Michael [ORNL] [ORNL; Younkin, James R [ORNL] [ORNL; Hines, Jairus B [ORNL] [ORNL; Laughter, Mark D [ORNL] [ORNL; Morgan, Jim [Innovative Solutions] [Innovative Solutions; Carrick, Bernie [USEC] [USEC; Boyer, Brian [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Whittle, K. [USEC] [USEC

2008-01-01

64

Phytoplankton processes during a mesoscale iron enrichment in the NE subarctic Pacific: Part II—Nutrient utilization  

NASA Astrophysics Data System (ADS)

The subarctic Pacific is one of the three main regions in which phytoplankton productivity is limited by the availability of iron (Fe). During the Subarctic Ecosystem Response to Iron Enrichment (SERIES) experiment, the response of phytoplankton to the addition of Fe and the consequential effects on chemical and physical water properties were monitored. Over the duration of the Fe-induced phytoplankton bloom, macronutrient concentrations (nitrate (NO 3), silicic acid (Si(OH) 4) and phosphate (PO 4)) were drawn down with Si(OH) 4 being depleted to low concentrations (<1 ?M) after 18 days. The dissolved Si(OH) 4: NO 3 ratio varied between two phases of the bloom. From days 0 to 10 (phase I), when all phytoplankton size classes increased in biomass, the dissolved Si(OH) 4: NO 3 ratio of the seawater in the patch increased as a result of the greater drawdown of NO 3. After day 10 (phase II), when diatoms dominated the patch, a rapid decline in Si(OH) 4 concentrations resulted in a sharp decrease in the Si(OH) 4: NO 3 ratio of the seawater. Increases in the suspended particulate biogenic silica (BSi) and particulate nitrogen (PN) resulted in a BSi: PN ratio of ca. 2 in the later stages of the Fe-induced bloom. The uptake of NO 3 was enhanced due to the Fe enrichment. In the patch, absolute NO 3 uptake rates increased in both large (?5 ?m) and small (<5 ?m) cells with the large cells accounting for 84% of total measured NO 3 uptake over the duration of the experiment. Biomass-specific NO 3 uptake rates also increased, but, in the small cells, the extent of the increase was largely dependent on the proxy for biomass used (PN or chlorophyll a). The photosynthetic efficiency of the phytoplankton assemblage was assessed at various stages of the bloom through the use of pulse amplitude-modulated (PAM) fluorometry. The trends in maximal and operational photochemical yields measured in the patch suggest that bloom termination resulted from a combination of Fe-stress and Si-stress. The observed changes in nutrient utilization during SERIES demonstrate the crucial role of Fe in regulating macronutrient inventories and NO 3 uptake rates by phytoplankton in Fe-limited regions such as the NE subarctic Pacific.

Marchetti, Adrian; Juneau, Philippe; Whitney, Frank A.; Wong, Chi-Shing; Harrison, Paul J.

2006-10-01

65

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

66

Carbon dioxide enrichment alleviates heat stress by improving cellular redox homeostasis through an ABA-independent process in tomato plants.  

PubMed

Plant responses to elevated CO2 and high temperature are critically regulated through a complex network of phytohormones and redox homeostasis. However, the involvement of abscisic acid (ABA) in plant adaptation to heat stress under elevated CO2 conditions has not been thoroughly studied. This study investigated the interactive effects of elevated CO2 (800 ?mol·mol(-1) ) and heat stress (42 °C for 24 h) on the endogenous level of ABA and the cellular redox state of two genotypes of tomato with different ABA biosynthesis capacities. Heat stress significantly decreased maximum photochemical efficiency of PSII (Fv/Fm) and leaf water potential, but also increased levels of malondialdehyde (MDA) and electrolyte leakage (EL) in both genotypes. Heat-induced damage was more severe in the ABA-deficient mutant notabilis (not) than in its parental cultivar Ailsa Craig (Ailsa), suggesting that a certain level of endogenous ABA is required to minimise the heat-induced oxidative damage to the photosynthetic apparatus. Irrespective of genotype, the enrichment of CO2 remarkably stimulated Fv/Fm, MDA and EL in heat-stressed plants towards enhanced tolerance. In addition, elevated CO2 significantly strengthened the antioxidant capacity of heat-stressed tomato seedlings towards a reduced cellular redox state for a prolonged period, thereby mitigating oxidative stress. However, elevated CO2 and heat stress did not alter the endogenous level of ABA or the expression of its biosynthetic gene NCED2 in either genotype, indicating that ABA is not involved in elevated CO2 -induced heat stress alleviation. The results of this study suggest that elevated CO2 alleviated heat stress through efficient regulation of the cellular redox poise in an ABA-independent manner in tomato plants. PMID:24985337

Li, X; Ahammed, G J; Zhang, Y Q; Zhang, G Q; Sun, Z H; Zhou, J; Zhou, Y H; Xia, X J; Yu, J Q; Shi, K

2015-01-01

67

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

68

Effective method for recovering and enriching tritium from tritiated water by dual-temperature HâO-Hâ exchange process  

Microsoft Academic Search

The composite packing with the hydrophobic platinum catalyst for the isotope exchange reaction in HâO-Hâ system was improved to be appreciably active. Therefore, it became realistic to design a process for tritium recovery by the dual-temperature exchange method. The separation performance of dual-temperature 5stage cascade (S3-E2) was simulated. The process was designed to be operated under the condition of P

A. Kitamoto; M. Shimizu; Y. Takashima

1985-01-01

69

Chromatin enrichment for proteomics.  

PubMed

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

2014-09-01

70

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

71

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

72

Expensive Enrichment  

ERIC Educational Resources Information Center

This article presents an economic analysis of the nuclear fuel reprocessing industry. It indicates that while environmental safety devices have improved the working conditions, they have also added ever-increasing costs to this necessary process. (MA)

Resnikoff, Marvin

1975-01-01

73

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

2008-01-01

74

Membrane processes for gas separations: Part I. Removal of carbon dioxide and hydrogen sulfide from low-quality natural gas. Part II. Enrichment of krypton in air  

NASA Astrophysics Data System (ADS)

I. The objective of this study was to determine the process design characteristics and economics of membrane separation processes for reducing the concentrations of H2S and CO2 in low-quality natural gas containing substantial amounts of the two acid gases to pipeline specifications ( ? 2 mole-% CO2 and ? 4 ppm H2S). The new processes considered the simultaneous use of two different types of polymer membranes for the above application, namely, one with higher CO2/CH4 selectivity and the other with higher H2S/CH4 selectivity. The performance and economics of membrane process configurations comprising one, two, and three permeation stages, with and without recycle streams, were examined and optimized via extensive computer simulations. Most computations assumed as a "base-case", the processing of a medium-size natural gas stream of 35 MMSCFD at 800 psia. The natural gas was taken to contain ? 10 mole-% H2S and ? 40 mole-% CO2. The most economical process configuration was two permeation stages in series, with H2S-selective membranes in the first stage and CO2-selective membranes in the second stage. The most economical process configurations for upgrading natural gas containing either only substantial amounts of H2S or of CO2 were also determined. The sensitivity of the process economics to feed flow rate, feed pressure, membrane module cost, and wellhead cost of natural gas was studied. A comparison of the processing cost of membrane processes with that of conventional gas absorption processes utilizing diethanolamine as solvent was also investigated. II. A membrane process for enrichment of Kr in air was studied experimentally as a technique of improving the accuracy of Kr analysis. "Asymmetric" silicone rubber membranes were found to be most suitable for this application. The study was investigated with a feed gas mixture containing 0.99 mole-% Kr, 20.70 mole-% O2, and 78.30 mole-% N2. The Kr concentration could be increased from 0.99 to 2.23 mole-% in a single membrane stage and further raised to 3.73 mole-% in two stages in cascade. Computer simulations of "cross-flow" model yielded results in general agreement with experimental data.

Hao, Jibin

1998-12-01

75

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

76

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

77

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

78

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

79

Selenium concentration and speciation in biofortified flour and bread: Retention of selenium during grain biofortification, processing and production of Se-enriched food.  

PubMed

The retention and speciation of selenium in flour and bread was determined following experimental applications of selenium fertilisers to a high-yielding UK wheat crop. Flour and bread were produced using standard commercial practices. Total selenium was measured using inductively coupled plasma-mass spectrometry (ICP-MS) and the profile of selenium species in the flour and bread were determined using high performance liquid chromatography (HPLC) ICP-MS. The selenium concentration of flour ranged from 30ng/g in white flour and 35ng/g in wholemeal flour from untreated plots up to >1800ng/g in white and >2200ng/g in wholemeal flour processed from grain treated with selenium (as selenate) at the highest application rate of 100g/ha. The relationship between the amount of selenium applied to the crop and the amount of selenium in flour and bread was approximately linear, indicating minimal loss of Se during grain processing and bread production. On average, application of selenium at 10g/ha increased total selenium in white and wholemeal bread by 155 and 185ng/g, respectively, equivalent to 6.4 and 7.1?g selenium per average slice of white and wholemeal bread, respectively. Selenomethionine accounted for 65-87% of total extractable selenium species in Se-enriched flour and bread; selenocysteine, Se-methylselenocysteine selenite and selenate were also detected. Controlled agronomic biofortification of wheat crops for flour and bread production could provide an appropriate strategy to increase the intake of bioavailable selenium. PMID:25213956

Hart, D J; Fairweather-Tait, S J; Broadley, M R; Dickinson, S J; Foot, I; Knott, P; McGrath, S P; Mowat, H; Norman, K; Scott, P R; Stroud, J L; Tucker, M; White, P J; Zhao, F J; Hurst, R

2011-06-15

80

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

81

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)

2010-08-10

82

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

83

Process development for the enrichment of curcuminoids in turmeric spent oleoresin and its inhibitory potential against LDL oxidation and angiotensin-converting enzyme.  

PubMed

Turmeric (Curcuma longa) contains biologically active colouring constituents, curcuminoids, which are isolated from the turmeric rhizome by solvent extraction. The mother liquor left after the separation of curcuminoids is known as turmeric spent oleoresin (SOT). The present study developed a method for the enrichment of curcuminoids in SOT. By using this method, curcuminoids in the SOT (8.4%) were doubled (17.5%). Presence of curcuminoids in enriched fraction was confirmed by high performance liquid chromatography (HPLC) and liquid chromatography coupled with mass spectroscopy analysis. Further studies on this fraction showed that it can effectively inhibit angiotensin-converting enzyme and low-density lipoprotein oxidation with IC(50) values of 19.45 ?g/ml and 30.52 ?g/ml, respectively. The results showed that curcuminoids enriched fraction (CEF) can reduce the risk of hypertension and cardiovascular diseases. In addition to this fraction, a turmerone-rich hexane fraction was also separated from the spent oleoresin. PMID:22263555

Nampoothiri, Suresh V; Praseetha, E K; Venugopalan, V V; Nirmala Menon, A

2012-09-01

84

Carburizing with CO enriched gas  

SciTech Connect

As the atmosphere for gas carburizing, many gases have been made commercially feasible as endothermic gas. Carburizing with endothermic gas of natural gas and air tends to degrade uniformity in the case depth of the product because the CO density is low. To deal with this, the authors carried out research on carburizing with CO-enriched endothermic (CEE) gas with CO density of 22--30% produced through reformulation of natural gas and oxygen with the aim of practical application. The authors developed an endothermic gas generator equipped with continuous gas carburizing equipment and uniform quality can be maintained even if large quantities of products are carburized by an overlapping process. In CO-enriched CEE carburizing, it is important to correctly manage the gas carburizing system, which consists of the gas composition, gas pressure, carburizing temperature, and the carbon potential.

Kanetake, N. [Metaltechnic Research Lab., Tokyo (Japan); Takahashi, S. [Kanto Yakin Kogyo Co., Ltd., Hiratsuka (Japan)

1995-12-31

85

Conversion of Molybdenum-99 production process to low enriched uranium: Neutronic and thermal hydraulic analyses of HEU and LEU target plates for irradiation in Pakistan Research Reactor-1  

NASA Astrophysics Data System (ADS)

Technetium-99m, the daughter product of Molybdenum-99 is the most widely needed radionuclide for diagnostic studies in Pakistan. Molybdenum-99 Production Facility has been established at PINSTECH. Highly enriched uranium (93% 235U) U/Al alloy targets have been irradiated in Pakistan Research Reactor-1 (PARR-1) for the generation of fission Mo-99, while basic dissolution technique is used for separation of Mo-99 from target matrix activity. In line with the international objective of minimizing and eventually eliminating the use of HEU in civil commerce, national and international efforts have been underway to shift the production of medical isotopes from HEU to LEU (LEU; <20% 235U enrichment) targets. To achieve the equivalent amount of 99Mo with LEU targets, approximately 5 times uranium is needed. LEU aluminum uranium dispersion target has been developed, which may replace existing HEU aluminum/uranium alloy targets for production of 99Mo using basic dissolution technique. Neutronic and thermal hydraulic calculations were performed for safe irradiation of targets in the core of PARR-1.

Mushtaq, Ahmad; Iqbal, Masood; Bokhari, Ishtiaq Hussain; Mahmood, Tayyab; Muhammad, Atta

2012-09-01

86

CLEAN: CLustering Enrichment ANalysis  

PubMed Central

Background Integration of biological knowledge encoded in various lists of functionally related genes has become one of the most important aspects of analyzing genome-wide functional genomics data. In the context of cluster analysis, functional coherence of clusters established through such analyses have been used to identify biologically meaningful clusters, compare clustering algorithms and identify biological pathways associated with the biological process under investigation. Results We developed a computational framework for analytically and visually integrating knowledge-based functional categories with the cluster analysis of genomics data. The framework is based on the simple, conceptually appealing, and biologically interpretable gene-specific functional coherence score (CLEAN score). The score is derived by correlating the clustering structure as a whole with functional categories of interest. We directly demonstrate that integrating biological knowledge in this way improves the reproducibility of conclusions derived from cluster analysis. The CLEAN score differentiates between the levels of functional coherence for genes within the same cluster based on their membership in enriched functional categories. We show that this aspect results in higher reproducibility across independent datasets and produces more informative genes for distinguishing different sample types than the scores based on the traditional cluster-wide analysis. We also demonstrate the utility of the CLEAN framework in comparing clusterings produced by different algorithms. CLEAN was implemented as an add-on R package and can be downloaded at . The package integrates routines for calculating gene specific functional coherence scores and the open source interactive Java-based viewer Functional TreeView (FTreeView). Conclusion Our results indicate that using the gene-specific functional coherence score improves the reproducibility of the conclusions made about clusters of co-expressed genes over using the traditional cluster-wide scores. Using gene-specific coherence scores also simplifies the comparisons of clusterings produced by different clustering algorithms and provides a simple tool for selecting genes with a "functionally coherent" expression profile. PMID:19640299

Freudenberg, Johannes M; Joshi, Vineet K; Hu, Zhen; Medvedovic, Mario

2009-01-01

87

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

88

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

89

rado School gifts enrich  

E-print Network

1.0 Color Such class progr the c A gift Foun anyth no co assur wishe Rece desir supp and is Scho there the S Foun beha Thus distin proce distin and p 2.0 BACKGR rado School gifts enrich sroom and la rams, library provided event wil may con cultural c in that so deductib Gift Soli Deposit Issued: Revised ROUND

90

Enriching software architecture documentation  

Microsoft Academic Search

The eective documentation of Architectural Knowledge (AK) is one of the key factors in leveraging the paradigm shift toward sharing and reusing AK. However, current documentation approaches have severe shortcomings in capturing the knowl- edge of large and complex systems and subsequently facilitating its usage. In this paper, we propose to tackle this problem through the enrichment of traditional architectural

Anton Jansen; Jan Salvador Van Der Ven

2009-01-01

91

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

92

Science Student Enrichment Opportunities.  

ERIC Educational Resources Information Center

This document was developed with the intention of increasing California public school students' awareness of and participation in science-related enrichment activities. Some of the activities are intended for participation by individuals, while others are meant for teams of students. These annual events are listed in chronological order for a…

California State Dept. of Education, Sacramento.

93

Development of an enrichment measurement technique and its application to enrichment verification of gaseous UF 6  

NASA Astrophysics Data System (ADS)

A technique has been developed to verify the enrichment of gaseous UF 6 inside cylinders. This technique combines an X-ray fluorescent measurement of the total amount of gaseous uranium with a measure of the 185.7 keV gamma ray from 235U using two collimators to obtain an enrichment that is independent of the pressure of the gaseous uranium and independent of the deposit that forms on a surface in contact with UF 6. This technique has the required sensitivity to determine whether the process gas is of uranium enrichment ? 20% or >20%.

Close, D. A.; Pratt, J. C.; Atwater, H. F.

1985-10-01

94

Processing and interpretation of ASTER TIR data for mapping of rare-metal-enriched albite granitoids in the Central Eastern Desert of Egypt  

NASA Astrophysics Data System (ADS)

ASTER level 1B (radiance at the sensor) TIR-bands and level 2B04 (surface emissivity) data were analyzed to detect four of 14 rare-metal-enriched albite granite, which are classified as I-type magnetite-series (G3 type) granites in the Central Eastern Desert of Egypt. Analysis of the shapes of laboratory emissivity spectrum of albite granite samples measured by portable emission spectrometer and albite mineral spectra from ASTER spectral library at the website of JPL of NASA showed that, albite granite samples has a higher emissivity in bands 12, 13 and 14 than in bands 10 and 11. To identify and map this type of granite, Quartz Index, as well as band ratios, band ratio combination and band combinations were used, based on the shapes of the analyzed emissivity spectrum of albite granite samples and albite mineral. The Quartz Index (QI) was high for quartz-rich/feldspar poor rocks and was low for K-feldspar or gypsum-rich rocks. Albite rich granites were detected as dark pixels in the QI image. The proposed band ratio b12/b11 clearly identified the albite granite bodies as dark regions. False color images of band combination of 14:12:10 and 12:13:11 in R:G:B clearly mapped the albite granite bodies as light brownish yellow and light greenish regions respectively. A new ASTER colored composite band ratio combination b12/b13:b11/b12:b14/b13 as R:G:B is applied successfully for mapping albite granite in the study area. This new combination clearly separated albite granite as pinkish magenta color. An ASTER scene covering the study area acquired on a different date was used to determine the effect of atmospheric and surface temperature conditions on the ratio and the mathematical band operation. The results indicated no significance differences.

Aboelkhair, Hatem; Ninomiya, Yoshiki; Watanabe, Yasushi; Sato, Isao

2010-08-01

95

Motif Enrichment Tool  

PubMed Central

The Motif Enrichment Tool (MET) provides an online interface that enables users to find major transcriptional regulators of their gene sets of interest. MET searches the appropriate regulatory region around each gene and identifies which transcription factor DNA-binding specificities (motifs) are statistically overrepresented. Motif enrichment analysis is currently available for many metazoan species including human, mouse, fruit fly, planaria and flowering plants. MET also leverages high-throughput experimental data such as ChIP-seq and DNase-seq from ENCODE and ModENCODE to identify the regulatory targets of a transcription factor with greater precision. The results from MET are produced in real time and are linked to a genome browser for easy follow-up analysis. Use of the web tool is free and open to all, and there is no login requirement. Address: http://veda.cs.uiuc.edu/MET/. PMID:24860165

Blatti, Charles; Sinha, Saurabh

2014-01-01

96

Using the Web for Social Studies Enrichment.  

ERIC Educational Resources Information Center

This article discusses the benefits of using the Internet to enrich the social studies curriculum and the need to teach students to evaluate every Web site they visit according to three criteria: reliability, authorship, and purpose. Questions are listed to aid students in this evaluation process, along with Web sites. (CR)

McCoach, D. Betsy

2002-01-01

97

Ion exchange enrichment of uranium isotopes  

Microsoft Academic Search

A process for the enrichment of one isotope in a mixture of uranium isotopes by passing a solution of the mixture in a solvent through an anion exchanger thereby forming on the anion exchanger a boundary (A) between a uranium adsorption zone and an adjacent reducing agent zone and\\/or a boundary (B) between a uranium adsorption zone and an adjacent

T. Miyake; H. Onitsuka; K. Takeda

1983-01-01

98

A Miscellany of Etceteras: An "In-Process" Collection of Interdisciplinary Units and Enrichment Lessons. New York and the World Project 1991-92.  

ERIC Educational Resources Information Center

These curriculum pieces, developed by teachers involved in the New York and the World Program, vary from single lessons to full units and indicate new approaches that all teachers can use in determining what to teach and how to teach it. The first section provides an overview of an interdisciplinary model along with steps in the process. The next…

Greenberg, Hazel Sara, Ed.

99

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

Microsoft Academic Search

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

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

2009-01-01

100

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

101

KEA: kinase enrichment analysis  

PubMed Central

Motivation: Multivariate experiments applied to mammalian cells often produce lists of proteins/genes altered under treatment versus control conditions. Such lists can be projected onto prior knowledge of kinase–substrate interactions to infer the list of kinases associated with a specific protein list. By computing how the proportion of kinases, associated with a specific list of proteins/genes, deviates from an expected distribution, we can rank kinases and kinase families based on the likelihood that these kinases are functionally associated with regulating the cell under specific experimental conditions. Such analysis can assist in producing hypotheses that can explain how the kinome is involved in the maintenance of different cellular states and can be manipulated to modulate cells towards a desired phenotype. Summary: Kinase enrichment analysis (KEA) is a web-based tool with an underlying database providing users with the ability to link lists of mammalian proteins/genes with the kinases that phosphorylate them. The system draws from several available kinase–substrate databases to compute kinase enrichment probability based on the distribution of kinase–substrate proportions in the background kinase–substrate database compared with kinases found to be associated with an input list of genes/proteins. Availability: The KEA system is freely available at http://amp.pharm.mssm.edu/lib/kea.jsp Contact: avi.maayan@mssm.edu PMID:19176546

Lachmann, Alexander; Ma'ayan, Avi

2009-01-01

102

Thermal breeder fuel enrichment zoning  

DOEpatents

A method and apparatus for improving the performance of a thermal breeder reactor having regions of higher than average moderator concentration are disclosed. The fuel modules of the reactor core contain at least two different types of fuel elements, a high enrichment fuel element and a low enrichment fuel element. The two types of fuel elements are arranged in the fuel module with the low enrichment fuel elements located between the high moderator regions and the high enrichment fuel elements. Preferably, shim rods made of a fertile material are provided in selective regions for controlling the reactivity of the reactor by movement of the shim rods into and out of the reactor core. The moderation of neutrons adjacent the high enrichment fuel elements is preferably minimized as by reducing the spacing of the high enrichment fuel elements and/or using a moderator having a reduced moderating effect.

Capossela, Harry J. (Schenectady, NY); Dwyer, Joseph R. (Albany, NY); Luce, Robert G. (Schenectady, NY); McCoy, Daniel F. (Latham, NY); Merriman, Floyd C. (Rotterdam, NY)

1992-01-01

103

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

104

Analysis of enrichment factor of uranium enrichment by Redox chromatography  

Microsoft Academic Search

Experiments and computer simulation show that the uranium enrichment factor in redox chromatography is determined substantially be electron exchange, isotope adsorption-desorption, and oxidation state adsorption-desorption equilibria. Computer simulation utilizing the theoretical model closely predicts the difference between the value of an enrichment factor derived from the solution equilibrium and that observed in the chromatographic isotope separation, which is attributable to

T. Muyake; K. Takeda; H. Onitsuka; T. Watanabe

1986-01-01

105

Enrichissement expérimental d'eaux printanières de claires à huîtres en baie de Bourgneuf (Vendée, France): augmentation de la biomasse et utilisation des éléments nutritifs par les algues unicellulaires  

Microsoft Academic Search

Oyster-pond sea-waters with natural populations were experimentally enriched to determine the nutrient limiting algal growth and the resulting effect on species composition. Results show that nitrogen is the limiting factor of growth-potential. N-NO3 alone is exhausted, while other ion concentrations remain always measurable. Addition of N-NO3 is needed to increase algal biomass. Favoured species differ when nitrogen is added alone

Jean-Michel Robert; Serge-Yves Maestrini; Maurice Héral; Yves Rincé; Jean-Paul Dreno; Léo Beker

1982-01-01

106

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

107

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

108

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

109

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

110

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

111

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

112

Tank 41H bounding uranium enrichment. Revision 1  

SciTech Connect

The intent of this document is to combine data from salt samples and historical process information to bound the uranium (U-235) enrichment which could be expected in the upper portion of the salt in Tank 41H. This bounding enrichment will be used in another document to establish a nuclear safety basis for initial salt removal operations. Any number of mixing scenarios could have been examined for the components which fed the evaporator during the formation of the last five feet of salt. The scenario presented was designed to be conservative, while still incorporating process knowledge and available data where possible. In the scenario, the lowest enrichment seen in any feed material was for the L4 feed which was evaporated to form the top part of the salt in Tank 41H. The lowest enrichment of 17% is still higher than the 16% (95% confidence) maximum enrichment actually found at the salt surface (from sample results). This leads to the conclusion that the uranium enrichment of the material (L1) which was being fed to the evaporate when the last five feet began to form, was lower than 22%. The conservatism used in this analysis, combined with the available sample data are believed to provide a defensible basis for establishing an upper bounding enrichment of 22% for the top five feet of salt.

Cavin, W.S.

1994-09-30

113

31 CFR 540.316 - Uranium enrichment.  

...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

114

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

115

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

116

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

117

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

118

High-purity, isotopically enriched bulk silicon  

SciTech Connect

The synthesis and characterization of dislocation-free, undoped, single crystals of Si enriched in all 3 stable isotopes is reported: {sup 28}Si (99.92%), {sup 29}Si (91.37%), and {sup 30}Si (89.8%). A silane-based process compatible with the relatively small amounts of isotopically enriched precursors that are practically available was used. The silane is decomposed to silicon on a graphite starter rod heated to 700-750 C in a recirculating flow reactor. A typical run produces 35 gm of polycrystalline Si at a growth rates of 5 {micro}m/min and conversion efficiency >95%. Single crystals are grown by the floating zone method and characterized by electrical and optical measurements. Concentrations of shallow dopants (P and B) are as low as mid-10{sup 13} cm{sup -3}. Concentrations of C and O lie below 10{sup 16} and 10{sup 15} cm{sup -3}, respectively.

Ager III, J.W.; Beeman, J.W.; Hansen, W.L.; Haller, E.E.; Sharp, I.D.; Liao, C.; Yang, A.; Thewalt, M.L.W.; Riemann, H.

2004-11-17

119

Development Issues on Linked Data Weblog Enrichment  

NASA Astrophysics Data System (ADS)

In this paper, we describe the issues found during the development of LinkedBlog, a Linked Data extension for WordPress blogs. This extension enables to enrich text-based and video information contained in blog entries with RDF triples that are suitable to be stored, managed and exploited by other web-based applications. The issues have to do with the generality, usability, tracking, depth, security, trustiness and performance of the linked data enrichment process. The presented annotation approach aims at maintaining web-based contents independent from the underlying ontological model, by providing a loosely coupled RDFa-based approach in the linked data application. Finally, we detail how the performance of annotations can be improved through a semantic reasoner.

Ruiz-Rube, Iván; Cornejo, Carlos M.; Dodero, Juan Manuel; García, Vicente M.

120

Evaporation of Enriched Uranium Solutions Containing Organophosphates  

SciTech Connect

The Savannah River Site has enriched uranium (EU) solution which has been stored for almost 10 years since being purified in the second uranium cycle of the H area solvent extraction process. The preliminary SRTC data, in conjunction with information in the literature, is promising. However, very few experiments have been run, and none of the results have been confirmed with repeat tests. As a result, it is believed that insufficient data exists at this time to warrant Separations making any process or program changes based on the information contained in this report. When this data is confirmed in future testing, recommendations will be presented.

Pierce, R.A.

1999-03-18

121

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

122

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

123

Enrichment of amino acid-oxidizing, acetate-reducing bacteria.  

PubMed

In anaerobic condition, amino acids are oxidatively deaminated, and decarboxylated, resulting in the production of volatile fatty acids. In this process, excess electrons are produced and their consumption is necessary for the accomplishment of amino acid degradation. In this study, we anaerobically constructed leucine-degrading enrichment cultures from three different environmental samples (compost, excess sludge, and rice field soil) in order to investigate the diversity of electron-consuming reaction coupled to amino acid oxidation. Constructed enrichment cultures oxidized leucine to isovalerate and their activities were strongly dependent on acetate. Analysis of volatile fatty acids (VFAs) profiles and community structure analysis during batch culture of each enrichment indicated that Clostridium cluster I coupled leucine oxidation to acetate reduction in the enrichment from the compost and the rice field soil. In these cases, acetate was reduced to butyrate. On the other hand, Clostridium cluster XIVb coupled leucine oxidation to acetate reduction in the enrichment from the excess sludge. In this case, acetate was reduced to propionate. To our surprise, the enrichment from rice field soil oxidized leucine even in the absence of acetate and produced butyrate. The enrichment would couple leucine oxidation to reductive butyrate synthesis from CO2. The coupling reaction would be achieved based on trophic link between hydrogenotrophic acetogenic bacteria and acetate-reducing bacteria by sequential reduction of CO2 and acetate. Our study suggests anaerobic degradation of amino acids is achieved yet-to-be described reactions. PMID:24630616

Ato, Makoto; Ishii, Masaharu; Igarashi, Yasuo

2014-08-01

124

The design of an automated electrolytic enrichment apparatus for tritium  

SciTech Connect

The Radiation Analytical Sciences Section at Laboratory at Lawrence Livermore National Laboratory performs analysis of low-level tritium concentrations in various natural water samples from the Tri-Valley Area, DOE Nevada Test Site, Site 300 in Tracy, CA, and other various places around the world. Low levels of tritium, a radioactive isotope of hydrogen, which is pre-concentrated in the RAS laboratory using an electrolytic enrichment apparatus. Later these enriched waters are analyzed by liquid scintillation counting to determine the activity of tritium. The enrichment procedure and the subsequent purification process by vacuum distillation are currently undertaken manually, hence being highly labor-intensive. The whole process typically takes about 2 to 3 weeks to complete a batch of 30 samples, with a dedicated personnel operating the process. The goal is to automate the entire process, specifically having the operation PC-LabVIEW{trademark} controlled with real-time monitoring capability. My involvement was in the design and fabrication of a prototypical automated electrolytic enrichment cell. Work will be done on optimizing the electrolytic process by assessing the different parameters of the enrichment procedure. Hardware and software development have also been an integral component of this project.

Myers, J.L.

1994-12-01

125

Conversion and Evaluation of the University of Massachusetts Lowell Research Reactor From High-Enriched To Low-Enriched Uranium Fuel  

Microsoft Academic Search

The process for converting the University of Massachusetts Lowell Research Reactor (UMLRR) from high-enrichment uranium (HEU) fuel to low-enrichment uranium (LEU) fuel began in 1988. Several years of design reviews, computational modeling, and thermal hydraulic analyses resulted in a preliminary reference core design and configuration based on 20 standard, MTR-type, flat-plate, 19.75% enriched, uranium silicide (u3Si2) fuel elements. A final

Leo M. Bobek

2003-01-01

126

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

SciTech Connect

The mission of this Conversion and Blending Facility (CBF) will be to blend surplus HEU metal and alloy with depleted uranium metal to produce an 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. The blended LEU will be produced as a waste suitable for storage or disposal.

NONE

1995-07-05

127

Enantiomeric Enrichment on the Prebiotic Earth  

NASA Astrophysics Data System (ADS)

Evaporation of an aqueous solution of a chiral, nonracemic (partially resolved) amino acid or hydroxy acid from a clay or silica surface is shown to produce crystals in six cases that possess increased concentrations of the more abundant enantiomer.The increases range from a factor of 1.2 as the low to a high greater than 6-fold above the near 8% enantiomeric excess starting levels. This newly discovered enantiomeric enrichment process is presented in the context of it having been a possible instrument in the attainment of levels of configurational homogeneity sufficient for the emergence of life on Earth.

Goldberg, Stanley I.

2007-02-01

128

Neuroprotective effects of cognitive enrichment  

Microsoft Academic Search

Cognitive enrichment early in life, as indicated by level of education, complexity of work environment or nature of leisure activities, appears to protect against the development of age-associated cognitive decline and also dementia. These effects are more robust for measures of crystallized intelligence than for measures of fluid intelligence and depend on the ability of the brain to compensate for

Norton W. Milgram; Christina T. Siwak-Tapp; Joseph Araujo; Elizabeth Head

2006-01-01

129

TOWARD AN ENRICHED CULTURAL FUTURE.  

ERIC Educational Resources Information Center

DEVELOPMENT OF INTEREST IN WORTHWHILE CULTURAL ACTIVITIES HAS BEEN ONE OF IMPORTANT EMPHASES OF THE HIGH HORIZONS PROGRAM. THE CULTURAL ENRICHMENT TEACHER HAS HAD THE RESPONSIBILITY FOR TEACHING MUSIC AND/OR ART IN ADDITION TO CORRELATING CULTURAL ACTIVITIES WITH ALL FACETS OF THE CURRICULUM TO PROVIDE INSPIRATION AND NEW EXPERIENCES AS WELL AS TO…

New York City Board of Education, Brooklyn, NY.

130

Enriched uranium recovery flowsheet improvements  

SciTech Connect

Savannah River uses 7.5% TBP to recover and purify enriched uranium. Adequate decontamination from fission products is necessary to reduce personnel exposure and to ensure that the enriched uranium product meets specifications. Initial decontamination of the enriched uranium from the fission products is carried out in the 1A bank, 16 stages of mixer-settlers. Separation of the enriched uranium from the fission product, /sup 95/Zr, has been adequate, but excessive solvent degradation caused by the long phase contact times in the mixer-settlers has limited the /sup 95/Zr decontamination factor (DF). An experimental program is investigating the replacement of the current 1A bank with either centrifugal contactors or a combination of centrifugal contactors and mixer-settlers. Experimental work completed has compared laboratory-scale centrifugal contactors and mixer-settlers for /sup 95/Zr removal efficiencies. Feed solutions spiked with actual plant solutions were used. The /sup 95/Zr DF was significantly better in the mixer-settlers than in the centrifugal contactors. As a result of this experimental study, a hybrid equipment flowsheet has been proposed for plant use. The hybrid equipment flowsheet combines the advantages of both types of solvent extraction equipment. Centrifugal contactors would be utilized in the extraction and initial scrub sections, followed by additional scrub stages of mixer-settlers.

Holt, D L

1986-01-01

131

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

Federal Register 2010, 2011, 2012, 2013

...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

132

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

133

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

134

Deuterium Enrichment of PAHs by VUV Irradiation of Interstellar Ices  

NASA Technical Reports Server (NTRS)

Laboratory results demonstrate that polycyclic aromatic hydrocarbons (PAHs) rapidly exchange their hydrogen atoms with those of nearby molecules when they are frozen into low-temperature ices and exposed to vacuum ultraviolet radiation. As a result, PAHs quickly become deuterium-enriched when VUV irradiated in D-containing ices. This mechanism has important consequences for several astrophysical issues owing to the ubiquitous nature of PAHs in the interstellar medium. For example, this process may explain the deuterium enrichments found in PAHs in meteorites and interplanetary dust particles. These results also provide general predictions about the molecular siting of the deuterium on aromatic materials in meteorites if this process produced a significant fraction of their D-enrichment.

Bernstein, Max P.; Sandford, Scott A.; Allamandola, Louis J.; Gillette, J. Seb; Zare, Richard N.; DeVincenzi, Donald (Technical Monitor)

1998-01-01

135

Measurement of uranium enrichment for gaseous uranium at low pressure  

NASA Astrophysics Data System (ADS)

X-ray fluorescence determines the amount of total uranium present in gaseous UF6 inside cascade header pipes of a uranium centrifuge enrichment facility. A highly collimated source, highly collimated detctor, and a very rigid, reproducible geometry are required. Two measurements of the 185.7 keV gamma ray from U-235 using two collimators determine the amount of U-235 present only in the gas phase. The ratio of the gas only U235 signal to the total uranium gas only signal is directly proportional to the enrichment of the process UF6 gas. This measurement technique is independent of the deposit that forms on a surface in contact with UF6. This measurement technique is independent of the pressure of the gaseous UF6. This technique has the required sensitivity to determine whether the process gas is of uranium enrichment less than or equal to 20% or 20%.

Close, D. A.; Pratt, J. C.; Atwater, H. F.; Malanify, J. J.; Nixon, K. V.; Speir, L. G.

136

Enrichment of phosphorylated peptides and proteins by selective precipitation methods.  

PubMed

Protein phosphorylation is one of the most prominent post-translational modifications involved in the regulation of cellular processes. Fundamental understanding of biological processes requires appropriate bioanalytical methods for selectively enriching phosphorylated peptides and proteins. Most of the commonly applied enrichment approaches include chromatographic materials including Fe(3+)-immobilized metal-ion affinity chromatography or metal oxides. In the last years, the introduction of several non-chromatographic isolation technologies has increasingly attracted the interest of many scientists. Such approaches are based on the selective precipitation of phosphorylated peptides and proteins by applying various metal cations. The excellent performance of precipitation-based enrichment methods can be explained by the absence of any stationary phase, resin or sorbent, which usually leads to unspecific binding. This review provides an overview of recently published methods for the selective precipitation of phosphorylated peptides and proteins. PMID:25587840

Rainer, Matthias; Bonn, Günther K

2015-01-01

137

Fast and Convenient 5-hydroxymethylcytosine Enrichment  

E-print Network

enrichment using the Thermo Scientific EpiJET 5-hmC Enrichment Kit. This kit uses highly specific enzymatic, such as Thermo ScientificT Milda Kaniusaite, Eimantas Astromskas, Gediminas Alzbutas, Renata Bruzaite, Arunas Lagunavicius. Thermo

Cai, Long

138

Enriching Music and Language Arts Experiences  

ERIC Educational Resources Information Center

The article focuses on enriching music and language arts experiences of students. Music can enrich literature and language arts, poetry, theater arts, transitions, science, and math, as well as help meet special learner needs. A well-understood example of enrichment is the alphabet song. A music or classroom teacher using the alphabet song helps…

Flohr, John W.

2006-01-01

139

Cognitive Education with Deaf Adolescents: Effects of Instrumental Enrichment.  

ERIC Educational Resources Information Center

Twenty-six deaf adolescents received instruction in a structured program of cognitive education called "Instrumental Enrichment." The program addresses, among other processes, comparison, classification, logical progression, spatial orientation, analysis and synthesis, and syllogistic thinking. Following training, the subjects showed significant…

Haywood, H. Carl; And Others

1988-01-01

140

Prevention and treatment of drug addiction by environmental enrichment  

Microsoft Academic Search

Environmental enrichment (EE) has been shown to have powerful beneficial effects on a variety of physiological and pathological processes. Accumulating evidence indicates that EE can mimic positive life experiences and prevent the development of drug addiction. More recently, EE has also been shown to eliminate already developed addiction-related behaviors and to reduce the risks of relapse. These preventive and “curative”

Marcello Solinas; Nathalie Thiriet; Claudia Chauvet; Mohamed Jaber

2010-01-01

141

An Enriched Writers' Workshop for Beginning Writers with Developmental Disabilities  

ERIC Educational Resources Information Center

This article describes comprehensive, high-quality writing instruction for students with developmental disabilities. The Enriched Writers' Workshop combines differentiated writing process instruction with social communication instruction and cognitive strategy instruction for students with complex writing needs across a wide range of ages. It…

Sturm, Janet M.

2012-01-01

142

RESEARCH ARTICLE Open Access Gene interaction enrichment and network  

E-print Network

to interpret in terms of the complex underlying biological processes. In addition, there are in many cases S Barnholtz-Sloan1,3,4 and Mark R Chance1,3,5 Abstract Background: The molecular behavior of biological this challenge, Gene Set Enrichment Analysis (GSEA) and others have been developed, which focus on alterations

Koyuturk, Mehmet

143

Methanogenic degradation of acetone by an enrichment culture  

Microsoft Academic Search

An anaerobic enrichment culture degraded 1 mol of acetone to 2 mol of methane and 1 mol of carbon dioxide. Two microorganisms were involved in this process, a filament-forming rod similar to Methanotrix sp. and an unknown rod with round to slightly pointed ends. Both organisms formed aggregates up to 300 µm in diameter. No fluorescing bacteria were observed indicating

H. Platen; B. Schink

1987-01-01

144

Disposition of excess highly enriched uranium status and update  

Microsoft Academic Search

This paper presents the status of the US DOE program charged with the disposition of excess highly enriched uranium (HEU). Approximately 174 metric tonnes of HEU, with varying assays above 20 percent, has been declared excess from US nuclear weapons. A progress report on the identification and characterization of specific batches of excess HEU is provided, and plans for processing

C. K. Williams; J. G. Arbital

1997-01-01

145

Network-based functional enrichment  

PubMed Central

Background Many methods have been developed to infer and reason about molecular interaction networks. These approaches often yield networks with hundreds or thousands of nodes and up to an order of magnitude more edges. It is often desirable to summarize the biological information in such networks. A very common approach is to use gene function enrichment analysis for this task. A major drawback of this method is that it ignores information about the edges in the network being analyzed, i.e., it treats the network simply as a set of genes. In this paper, we introduce a novel method for functional enrichment that explicitly takes network interactions into account. Results Our approach naturally generalizes Fisher’s exact test, a gene set-based technique. Given a function of interest, we compute the subgraph of the network induced by genes annotated to this function. We use the sequence of sizes of the connected components of this sub-network to estimate its connectivity. We estimate the statistical significance of the connectivity empirically by a permutation test. We present three applications of our method: i) determine which functions are enriched in a given network, ii) given a network and an interesting sub-network of genes within that network, determine which functions are enriched in the sub-network, and iii) given two networks, determine the functions for which the connectivity improves when we merge the second network into the first. Through these applications, we show that our approach is a natural alternative to network clustering algorithms. Conclusions We presented a novel approach to functional enrichment that takes into account the pairwise relationships among genes annotated by a particular function. Each of the three applications discovers highly relevant functions. We used our methods to study biological data from three different organisms. Our results demonstrate the wide applicability of our methods. Our algorithms are implemented in C++ and are freely available under the GNU General Public License at our supplementary website. Additionally, all our input data and results are available at http://bioinformatics.cs.vt.edu/~murali/supplements/2011-incob-nbe/. PMID:22479706

2011-01-01

146

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

147

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

Microsoft Academic Search

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

Norman C. Anheier; Bruce A. Bushaw

2009-01-01

148

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

149

Involvement of glycosphingolipid-enriched lipid rafts in inflammatory responses.  

PubMed

Glycosphingolipids (GSLs) are membrane components consisting of hydrophobic ceramide and hydrophilic sugar moieties. GSLs cluster with cholesterol in cell membranes to form GSL-enriched lipid rafts. Biochemical analyses have demonstrated that GSL-enriched lipid rafts contain several kinds of transducer molecules, including Src family kinases. Among the GSLs, lactosylceramide (LacCer, CDw17) can bind to various microorganisms, is highly expressed on the plasma membranes of human phagocytes, and forms lipid rafts containing the Src family tyrosine kinase Lyn. LacCer-enriched lipid rafts mediate immunological and inflammatory reactions, including superoxide generation, chemotaxis, and non-opsonic phagocytosis. Therefore, LacCer-enriched membrane microdomains are thought to function as pattern recognition receptors (PRRs), which recognize pathogen-associated molecular patterns (PAMPs) expressed on microorganisms. LacCer also serves as a signal transduction molecule for functions mediated by CD11b/CD18-integrin (?M/?2-integrin, CR3, Mac-1), as well as being associated with several key cellular processes. LacCer recruits PCK?/? and phospholipase A2 to stimulate PECAM-1 expression in human monocytes and their adhesion to endothelial cells, as well as regulating ?1-integrin clustering and endocytosis on cell surfaces. This review describes the organizational and inflammation-related functions of LacCer-enriched lipid rafts. PMID:25553454

Iwabuchi, Kazuhisa

2015-01-01

150

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

151

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

152

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

153

Technologic enrichment of a community needs assessment.  

PubMed

In this article, we have reported the implementation and evaluation of a project to improve the community needs assessment process and product through technologic enhancement. Our description of the method reveals our heavy emphasis on the ethnographic approach in this model of community analysis. An Academic Enrichment Grant provided the two of us, community health nursing faculty members, funding to purchase tape recorders, a transcriber, a laptop computer, and a printer to facilitate the needs assessment. We evaluated the project in terms of accuracy, enhanced analysis, ease and efficiency, and student learning of ethnographic methods. The project did improve accuracy and enhanced the analysis. Although it improved ease of data collection, organization, and presentation, it did not produce a savings in time. It did facilitate student learning of ethnographic interviewing and analysis. Recommendations included expanding the use of technology, increasing training and student responsibility, and expanding the actual needs assessment to a two-semester project. PMID:1570221

Smith, M C; Barton, J A

1992-01-01

154

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

155

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

156

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

157

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

158

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

159

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

160

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

161

31 CFR 540.308 - Low Enriched Uranium (LEU).  

... 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

162

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

163

31 CFR 540.306 - Highly Enriched Uranium (HEU).  

...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

164

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

165

Incorporation of (57)Fe-isotopically enriched in apoferritin: formation and characterization of isotopically enriched Fe nanoparticles for metabolic studies.  

PubMed

The use of (57)Fe-isotopically enriched ferritin for the accurate measurement of Fe?:?ferritin ratios is proposed for metabolic studies. Thus, the synthesis of (57)Fe-isotopically enriched ferritin from horse apo-ferritin and isotopically enriched (NH4)2(57)Fe(II)(SO4)2 (Mohr's salt) is conducted. Size exclusion chromatography on-line with UV-VIS absorption (at 380 nm) is used in order to monitor the loading process of apo-ferritin. These studies revealed that the Fe-incorporation process involves also the formation of protein aggregates (oligomers) showing higher molecular mass than ferritin. A final optimized protocol involving incubation of the synthesized standard with guanidine hydrochloride (pH 3.5) has provided the best conditions for maintaining a stable protein structure without aggregates. Such (57)Fe-isotopically enriched ferritin was characterized and contained an average of 2200 atoms of Fe per mole of ferritin. The evaluation of the Fe-core after saturation with (57)Fe by Transmission Electron Microscopy (TEM) has revealed the formation of (57)Fe nanoparticles with a similar diameter to that of the commercial Fe-containing ferritin, confirming the process of Fe uptake, oxidation and mineralization within the protein cavity. The synthesized (57)Fe-ferritin shows great potential as a nanometabolic tracer to study the kinetics of Fe release in the cases of iron metabolic disorders. PMID:25170527

Konz, T; Montes-Bayón, M; Sanz-Medel, A

2014-11-01

166

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

Federal Register 2010, 2011, 2012, 2013

...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

167

Modeling Prosodic Structures in Linguistically Enriched Environments  

E-print Network

Modeling Prosodic Structures in Linguistically Enriched Environments Gerasimos Xydas, Dimitris Intelligence (LNAI), Vol. 3206 521 #12;2 Gerasimos Xydas, Dimitris Spiliotopoulos, Georgios Kouroupetroglou

Kouroupetroglou, Georgios

168

Negative Enrichment of Target Cells by Microfluidic Affinity Chromatography  

PubMed Central

A three-dimensional microfluidic channel was developed for high purity cell separations. This system featured high capture affinity using multiple vertical inlets to an affinity surface. In cell separations, positive selection (capture of the target cell) is usually employed. Negative enrichment, the capture of non-target cells and elution of target cells, has distinct advantages over positive selection. In negative enrichment, target cells are not labeled, and are not subjected to strenuous elution conditions or dilution. As a result, negative enrichment systems are amenable to multi-step processes in microfluidic systems. In previous work, we reported cell capture enhancement effects at vertical inlets to the affinity surface. In this study, we designed a chip that has multiple vertical and horizontal channels, forming a three-dimensional separation system. Enrichment of target cells showed separation purities of 92-96%, compared with straight-channel systems (77% purity). A parallelized chip was also developed for increased sample throughput. A two-channel showed similar separation purity with twice the sample flow rate. This microfluidic system, featuring high separation purity, ease of fabrication and use, is suitable for cell separations when subsequent analysis of target cells is required. PMID:21939198

Li, Peng; Gao, Yan; Pappas, Dimitri

2011-01-01

169

Substrate versatility of polyhydroxyalkanoate producing glycerol grown bacterial enrichment culture.  

PubMed

Waste-based polyhydroxyalkanoate (PHA) production by bacterial enrichments generally follows a three step strategy in which first the wastewater is converted into a volatile fatty acid rich stream that is subsequently used as substrate in a selector and biopolymer production units. In this work, a bacterial community with high biopolymer production capacity was enriched using glycerol, a non-fermented substrate. The substrate versatility and PHA production capacity of this community was studied using glucose, lactate, acetate and xylitol as substrate. Except for xylitol, very high PHA producing capacities were obtained. The PHA accumulation was comparable or even higher than with glycerol as substrate. This is the first study that established a high PHA content (?70 wt%) with glucose as substrate in a microbial enrichment culture. The results presented in this study support the development of replacing pure culture based PHA production by bacterial enrichment cultures. A process where mixtures of substrates can be easily handled and the acidification step can potentially be avoided is described. PMID:25213684

Moralejo-Gárate, Helena; Kleerebezem, Robbert; Mosquera-Corral, Anuska; Campos, José Luis; Palmeiro-Sánchez, Tania; van Loosdrecht, Mark C M

2014-12-01

170

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

171

FUEL ENRICHMENT FOR THE ENRICO FERMI REACTOR  

Microsoft Academic Search

The enrichment of the Enrico Fermi core was determined by calculations ; based on critical experiments and was established at 25.6% contained U²³⁵ ; for a total uranium contest of 1734 kg. This enrichment should ensure ; criticality for a minimum of 91 subassemblies assuming an equllibrium core for a ; burn-up of one percent. The uncertainty is estimated to

Garelis

1959-01-01

172

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

173

Initial report on characterization of excess highly enriched uranium  

SciTech Connect

DOE`s Office of Fissile Materials Disposition assigned to this Y-12 division the task of preparing a report on the 174.4 metric tons of excess highly enriched U. Characterization included identification by category, gathering existing data (assay), defining the likely needed processing steps for prepping for transfer to a blending site, and developing a range of preliminary cost estimates for those steps. Focus is on making commercial reactor fuel as a final disposition path.

NONE

1996-07-01

174

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

175

Enrichment of the Intracluster Medium  

E-print Network

The relevance of galaxies of different luminosity and mass for the chemical enrichment of the intracluster medium (ICM) is analysed. For this purpose, I adopt the composite luminosity function of cluster galaxies from Trentham (1998), which exhibits a significant rise at the very faint end. The model - adopting a universal Salpeter IMF - is calibrated on reproducing the M_Fe/L_tot, M_Fe/M_*, and alpha/Fe ratios observed in clusters. Although the contribution to total luminosity and ICM metals peaks around L* galaxies (M* approx -20), faint objects with M_B>-18 still provide at least 30 per cent of the metals present in the ICM. In consistency with the solar alpha/Fe ratios determined by {ASCA}, the model predicts that 60 per cent of the ICM iron comes from Type Ia supernovae. The predicted slope of the relation between intracluster gas mass and cluster luminosity emerges shallower than the observed one, indicating that the fraction of primordial gas increases with cluster richness.

D. Thomas

1998-11-25

176

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

177

Neutron-physical and thermohydraulic calculations of VVR-SM with high-and low-enrichment uranium fuel assemblies  

Microsoft Academic Search

The VVR-SM reactor at the Institute of Nuclear Physics of the Academy of Sciences of Uzbekistan is being converted from fuel\\u000a assemblies with high-enrichment uranium (36% 235U) to fuel assemblies with low-enrichment uranium (19.7% 235U). During the conversion process consisting of nine cycles, the IRT-3M fuel assemblies with high-enrichment uranium, which\\u000a are removed at the end of each cycle, will

S. A. Baitelesov; A. A. Dosimbaev; F. R. Kungurov

2008-01-01

178

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

179

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

180

Method for isotope enrichment by photoinduced chemiionization  

DOEpatents

Isotope enrichment, particularly .sup.235 U enrichment, is achieved by irradiating an isotopically mixed vapor feed with radiant energy at a wavelength or wavelengths chosen to selectively excite the species containing a desired isotope to a predetermined energy level. The vapor feed if simultaneously reacted with an atomic or molecular reactant species capable of preferentially transforming the excited species into an ionic product by a chemiionization reaction. The ionic product, enriched in the desired isotope, is electrostatically or electromagnetically extracted from the reaction system.

Dubrin, James W. (Walnut Creek, CA)

1985-01-01

181

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

182

21 CFR 866.2330 - Enriched culture medium.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Enriched culture medium. 866.2330...866.2330 Enriched culture medium. (a) Identification. An enriched culture medium is a device...vitamins, and extracts of plant or animal tissues. The device is...

2010-04-01

183

Co-enriching microflora associated with culture based methods to detect Salmonella from tomato phyllosphere.  

PubMed

The ability to detect a specific organism from a complex environment is vitally important to many fields of public health, including food safety. For example, tomatoes have been implicated numerous times as vehicles of foodborne outbreaks due to strains of Salmonella but few studies have ever recovered Salmonella from a tomato phyllosphere environment. Precision of culturing techniques that target agents associated with outbreaks depend on numerous factors. One important factor to better understand is which species co-enrich during enrichment procedures and how microbial dynamics may impede or enhance detection of target pathogens. We used a shotgun sequence approach to describe taxa associated with samples pre-enrichment and throughout the enrichment steps of the Bacteriological Analytical Manual's (BAM) protocol for detection of Salmonella from environmental tomato samples. Recent work has shown that during efforts to enrich Salmonella (Proteobacteria) from tomato field samples, Firmicute genera are also co-enriched and at least one co-enriching Firmicute genus (Paenibacillus sp.) can inhibit and even kills strains of Salmonella. Here we provide a baseline description of microflora that co-culture during detection efforts and the utility of a bioinformatic approach to detect specific taxa from metagenomic sequence data. We observed that uncultured samples clustered together with distinct taxonomic profiles relative to the three cultured treatments (Universal Pre-enrichment broth (UPB), Tetrathionate (TT), and Rappaport-Vassiliadis (RV)). There was little consistency among samples exposed to the same culturing medias, suggesting significant microbial differences in starting matrices or stochasticity associated with enrichment processes. Interestingly, Paenibacillus sp. (Salmonella inhibitor) was significantly enriched from uncultured to cultured (UPB) samples. Also of interest was the sequence based identification of a number of sequences as Salmonella despite indication by all media, that samples were culture negative for Salmonella. Our results substantiate the nascent utility of metagenomic methods to improve both biological and bioinformatic pathogen detection methods. PMID:24039862

Ottesen, Andrea R; Gonzalez, Antonio; Bell, Rebecca; Arce, Caroline; Rideout, Steven; Allard, Marc; Evans, Peter; Strain, Errol; Musser, Steven; Knight, Rob; Brown, Eric; Pettengill, James B

2013-01-01

184

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

185

Management's Ecstasy and Disparity Over Job Enrichment  

ERIC Educational Resources Information Center

A case study analyzing job enrichment schemes and manager expectations of increased productivity is presented. It was found that it was the managers' expectations of increased productivity, not the reorganization of work, that led to higher productivity. (EC)

King, Albert S.

1976-01-01

186

High School Enrichment Program 2014 APPLICATION FORM  

E-print Network

High School Enrichment Program 2014 APPLICATION FORM PART A ­ TO BE COMPLETED BY STUDENT Name)____________________________ ________________________________ Name of School that _______________________________________________________________________ be accepted for registration. School Division/District Name

Martin, Jeff

187

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

188

Optimization of Selenium-Enriched Mycelium of Lentinula edodes (Berk.) Pegler as a Food Supplement  

Microsoft Academic Search

Our goal was to optimize the growth conditions of submerged mycelial cultures of Lentinula edodes (Shiitake mushroom) in order to obtain a new dietary supplement enriched in selenium We designed a process technology in which mycelial cultures were cultivated in media composed of beet molasses, 10%; liquid stillage, 5%; corn steep liquor, 0.15%; and KH2PO4, 0.3%, enriched with selenium in

Jadwiga Tur?o; Bo?enna Gutkowska; Franciszek Herold; Marzenna Klimaszewska; Piotr Suchocki

2010-01-01

189

77 FR 823 - Guidance for Fuel Cycle Facility Change Processes  

Federal Register 2010, 2011, 2012, 2013

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

2012-01-06

190

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

191

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

192

ChIP-Enrich: gene set enrichment testing for ChIP-seq data.  

PubMed

Gene set enrichment testing can enhance the biological interpretation of ChIP-seq data. Here, we develop a method, ChIP-Enrich, for this analysis which empirically adjusts for gene locus length (the length of the gene body and its surrounding non-coding sequence). Adjustment for gene locus length is necessary because it is often positively associated with the presence of one or more peaks and because many biologically defined gene sets have an excess of genes with longer or shorter gene locus lengths. Unlike alternative methods, ChIP-Enrich can account for the wide range of gene locus length-to-peak presence relationships (observed in ENCODE ChIP-seq data sets). We show that ChIP-Enrich has a well-calibrated type I error rate using permuted ENCODE ChIP-seq data sets; in contrast, two commonly used gene set enrichment methods, Fisher's exact test and the binomial test implemented in Genomic Regions Enrichment of Annotations Tool (GREAT), can have highly inflated type I error rates and biases in ranking. We identify DNA-binding proteins, including CTCF, JunD and glucocorticoid receptor ? (GR?), that show different enrichment patterns for peaks closer to versus further from transcription start sites. We also identify known and potential new biological functions of GR?. ChIP-Enrich is available as a web interface (http://chip-enrich.med.umich.edu) and Bioconductor package. PMID:24878920

Welch, Ryan P; Lee, Chee; Imbriano, Paul M; Patil, Snehal; Weymouth, Terry E; Smith, R Alex; Scott, Laura J; Sartor, Maureen A

2014-07-01

193

Test the effects of nutrient enrichment on organic carbon storage in western Pacific oligotrophic gyre  

NASA Astrophysics Data System (ADS)

In order to test the hypothesis that enrichment of nitrate and phosphate would decrease storage of organic carbon in the ocean (Jiao et al., 2011), we conducted a series of in-situ incubation experiments in the western Pacific Ocean. Five treatments were employed: organic carbon (glucose or algal exudation organic matter (EOM)) and macronutrient (nitrate and phosphate) were added alone or in combination with each other. The final concentration of organic carbon and macronutrient in treatments were 10 ?M/C/kg, 1.5 ?M/N/kg and 0.15 ?M/P/ respectively higher than those in controls. Total dissolved organic matter (TOC) concentration, bacterial abundance, and nitrate and phosphate concentration were monitored during the incubation processes. The results showed that the utilization of TOC and bacterial community growth rate were enhanced by inorganic nutrients enrichment treatments during the initial 48 hours incubation, regardless of glucose enrichment or not. Until the end of 14 days incubation, the percentage of remaining additional organic carbon was significant higher in the glucose enrichment treatments and EOM enrichment treatments (40.64% and 55.05%, respectively), compared to the combination of glucose and inorganic nutrients enrichment treatment (4.52%). These results suggest that inorganic nutrients enrichment condition may be adverse to short-term scale carbon storage, presumably due to the nutrient-stimulated bacterial metabolism and respiration, which is consistent to the hypothesis.

liu, J.; Jiao, N.; Tang, K.

2013-12-01

194

Enriched Mantle II: a new view from the Samoan Hotspot  

NASA Astrophysics Data System (ADS)

An in-depth Sr-Nd-Pb isotope and trace element study of the EMII-defining Samoan hotspot lavas leads to a new working hypothesis for the origin of this high 87/86 Sr mantle endmember. Systematics of the Samoan fingerprint include 1) increasing 206/204 Pb with time - from 18.6 at 3 m.y. to 19.4 at present day, 2) en-echelon arrays in 206/204-208/204 Pb which correspond to the two topographic lineaments of the 375 km long volcanic chain, 3) the highest 87/86 Sr (0.7089) of all oceanic basalts, 4) an asymptotic decrease in 3/4 He from 24Ra (Farley et al., 1992) to the MORB value of 8Ra with increasing 87/86 Sr, and 5) mixing among three components which are best described as the enriched mantle, the depleted FOZO, and the (even more depleted) MORB Mantle. Trace element patterns of the lavas are generally smooth, with the exception of negative Pb and K anomalies, and show concentrations up to 100 times primitive mantle. A theoretical, pure EMII lava composition has been calculated with an isotopically-constrained unmixing of the most and least enriched lavas; the result indicates an extremely smooth trace element pattern with only slight negative anomalies at Ti and Ba. Additionally, a trace element inversion scheme (e.g. Hart et al., 1997) of an isotopically homogeneous sub-suite of FOZO-esque samples leads to the commonly observed contradiction of a source which is smoothly enriched in trace elements but with depleted isotopic ratios. Hence, trace element enrichment in the depleted source must result from a recent event of self-impregnation. The smooth trace element patterns of both the calculated enriched melt and isotopically depleted source leads to the conclusion that terrigenous or pelagic sediment, with their acute HFSE depletions and Pb/Ce enrichments, cannot explain the origin of EMII with any amount of dilution by a depleted (and more common) mantle. Instead, the origin of the EMII reservoir must be inherently associated with rather unadulterated mantle melting processes and melt/rock segregation at some point in the geologic past. Recycling of melt-impregnated oceanic lithosphere is one such example. Farley, K.A., Natland, J.H., Craig, H. (1992) EPSL v.111, p.193-199 Hart, S.R., Blusztajn, J., LeMasurier, W.E., Rex, D.C. (1997) Chemical Geology v.139, p.223-248

Workman, R. K.; Hart, S. R.; Blusztajn, J.; Jackson, M.; Kurz, M.; Staudigel, H.

2003-04-01

195

Application of polyimide membranes for biogas purification and enrichment.  

PubMed

Biogas is a clean environment friendly fuel that is produced by bacterial conversion of organic matter under anaerobic (oxygen-free) conditions. Raw biogas contains about 55-65% methane (CH(4)), 30-45% carbon dioxide (CO(2)), traces of hydrogen sulphide (H(2)S) and fractions of water vapour. Pure methane has a calorific value of 9100 kcal/m(3) at 15.5 degrees C and 1 atm; the calorific value of biogas varies from 4800 to 6900 kcal/m(3). To achieve the standard composition of the biogas and calorific value of 5500 kcal/m(3) the treatment techniques like absorption or membrane separation should be applied. In the paper the results of the tests of the CH(4) enrichment in simulated biogas mixture consisted of methane, carbon dioxide and hydrogen sulphide were presented. It was showed that using the capillary module with polyimide membranes it was possible to achieve the enrichment of CH(4) from the concentrations of 55-85% up to 91-94.4%. The membrane material was resistant to the small concentrations of sour gases and assured the reduction of H(2)S and water vapour concentrations, as well. The required enrichment was achieved in the single module, however to prevent CH(4) losses the multistage or hybrid systems should be used to improve process efficiency. PMID:17324508

Harasimowicz, M; Orluk, P; Zakrzewska-Trznadel, G; Chmielewski, A G

2007-06-18

196

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

197

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

198

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

199

Anti-craving effects of environmental enrichment  

PubMed Central

We hypothesized that environmental enrichment in rats may reduce cocaine-seeking behaviour elicited by cocaine-priming injections and by cocaine-associated cues. Rats trained to self-administer cocaine while housed in isolated conditions were then assigned to live in isolation or an enriched environment for 21 d of forced abstinence. Subsequently, extinction and reinstatement of cocaine-seeking behaviour (operant responses without cocaine available) were assessed. Expt 1 showed that enrichment resulted in less cocaine-seeking behaviour during extinction and cue-elicited reinstatement compared to continued isolation housing, but had no effect on cocaine-primed reinstatement. A subsequent experiment, which included a pair-housed group to control for potential isolation stress, again demonstrated that enrichment attenuated cocaine seeking during extinction, but not cocaine-primed reinstatement, relative to both isolation and pair-housed conditions. The findings suggest that enrichment reduces the impact of cocaine-associated environmental stimuli, and hence it may be a useful intervention for attenuating cue-elicited craving in humans. PMID:19691875

Thiel, Kenneth J.; Sanabria, Federico; Pentkowski, Nathan S.; Neisewander, Janet L.

2010-01-01

200

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

201

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

202

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

203

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

Microsoft Academic Search

The US and UK have been separately working on the development of a NDA instrument to determine the enrichment of gaseous UFâ 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,

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

1985-01-01

204

Nutrient enrichment increases mortality of mangroves.  

PubMed

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

205

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

206

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

207

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

208

The r-Process Enriched Low Metallicity Giant HD 115444  

E-print Network

New high resolution, very high signal-to-noise spectra of ultra-metal-poor (UMP) giant stars HD 115444 and HD 122563 have been gathered with the High-Resolution Echelle Spectrometer of the McDonald Observatory 2.7m Telescope. With these spectra, line identification and model atmosphere analyses have been conducted, emphasizing the neutron-capture elements. Twenty elements with Z > 30 have been identified in the spectrum of HD 115444. This star is known to have overabundances of the neutron-capture elements, but it has lacked a detailed analysis necessary to compare with nucleosynthesis predictions. The new study features a line-by-line differential abundance comparison of HD 115444 with the bright, well-studied halo giant HD 122563. For HD 115444, the overall metallicity is [Fe/H]~ -3.0. The abundances of the light and iron-peak elements generally show the same pattern as other UMP stars (e.g. overdeficiencies of manganese and chromium, overabundances of cobalt), but the differential analysis indicates several nucleosynthesis signatures that are unique to each star.

Jenny Westin; Christopher Sneden; Bengt Gustafsson; John J. Cowan

1999-10-20

209

Oxygen Enrichment in the Process and Chemical Industries  

E-print Network

an air oxidation step (Table 1). Some Organic Intermediates Produced by Air Oxidation: ? Adipic Acid ? Acetaldehyde ? Acetic Acid ? Acrylonitrile ? Acrylic Acid ? Acetone ? Ethylene Oxide ? Formaldehyde ? Maleic Anhydride ? Phenol... ? Phthallic Anhydride ? Propylene Oxide TABLE 1 \\-Jith the national economy showing signs of s rong improvement, it is fel t that there may be si ua tions in which the use of oxygen or oxygen-e riched air as a means of debottlenecking an air-bas d plant...

Milne, R. T.

1984-01-01

210

Enriching Science and Math through Engineering  

ERIC Educational Resources Information Center

This case study reviewed the collaborative efforts of university engineers, teacher educators, and middle school teachers to advance sixth- and seventh-grade students' learning through a series of project-based engineering activities. This two-year project enriched regular school curricula by introducing real-world applications of science and…

Redmond, Adrienne; Thomas, Julie; High, Karen; Scott, Margaret; Jordan, Pat; Dockers, Jean

2011-01-01

211

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.

212

Weighted set enrichment of gene expression data  

PubMed Central

Background Sets of genes that are known to be associated with each other can be used to interpret microarray data. This gene set approach to microarray data analysis can illustrate patterns of gene expression which may be more informative than analyzing the expression of individual genes. Various statistical approaches exist for the analysis of gene sets. There are three main classes of these methods: over-representation analysis, functional class scoring, and pathway topology based methods. Methods We propose weighted hypergeometric and weighted chi-squared methods in order to assign a rank to the degree to which each gene participates in the enrichment. Each gene is assigned a weight determined by the absolute value of its log fold change, which is then raised to a certain power. The power value can be adjusted as needed. Datasets from the Gene Expression Omnibus are used to test the method. The significantly enriched pathways are validated through searching the literature in order to determine their relevance to the dataset. Results Although these methods detect fewer significantly enriched pathways, they can potentially produce more relevant results. Furthermore, we compare the results of different enrichment methods on a set of microarray studies all containing data from various rodent neuropathic pain models. Discussion Our method is able to produce more consistent results than other methods when evaluated on similar datasets. It can also potentially detect relevant pathways that are not identified by the standard methods. However, the lack of biological ground truth makes validating the method difficult. PMID:24565001

2013-01-01

213

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

214

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

215

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

216

Current methods for phosphoprotein isolation and enrichment  

Microsoft Academic Search

The phosphorylation of proteins is a central paradigm of signal transduction. The substitution of neutral hydroxyl groups of serine, threonine and tyrosine with a negatively charged phosphate group alters the physicochemical and immunogenic properties of the protein, which then can be used to isolate these isoforms. In the last decades several different techniques were applied, attempting to selectively enrich protein

Stefan R. Schmidt; Fritz Schweikart; Martin E. Andersson

2007-01-01

217

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.

218

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

219

SIGIR WORKSHOP REPORT Enriching Information Retrieval  

E-print Network

SIGIR WORKSHOP REPORT Enriching Information Retrieval Paul N. Bennett Microsoft Research paul.n.bennett@microsoft@cs.cornell.edu Krysta M. Svore Microsoft Research ksvore@microsoft.com 1 Introduction Most information retrieval systems ontologies, usage patterns, locality information, readability, temporal). · The automatic acquisition

Joachims, Thorsten

220

Subcritical Neutron Amplifier Based on Enriched Uranium  

Microsoft Academic Search

The present work is devoted to an investigation of the properties of a subcritical system consisting of enriched uranium, an amplifier of a neutron flux from an external source, and a power amplifier, depending on the composition of the system and the energy of the neutrons from the source [1?3]. The geometric size of the assembly was determined from the

V. A. Babenko; L. L. Enkovskii; V. N. Pavlovich; E. A. Pupirina

2002-01-01

221

Conversion and Evaluation of the University of Massachusetts Lowell Research Reactor From High-Enriched To Low-Enriched Uranium Fuel  

SciTech Connect

The process for converting the University of Massachusetts Lowell Research Reactor (UMLRR) from high-enrichment uranium (HEU) fuel to low-enrichment uranium (LEU) fuel began in 1988. Several years of design reviews, computational modeling, and thermal hydraulic analyses resulted in a preliminary reference core design and configuration based on 20 standard, MTR-type, flat-plate, 19.75% enriched, uranium silicide (u3Si2) fuel elements. A final safety analysis for the fuel conversion was submitted to the Nuclear Regulatory Commission (NRC) in 1993. The NRC made two additional requests for additional information and supplements were submitted in 1994 and 1997. The new UMLRR Reactor Supervisor initiated an effort to change the LEU reference core configuration to eliminate a complicated control rod modification needed for the smaller core.

Leo M. Bobek

2003-11-19

222

Reproducible Automated Phosphopeptide Enrichment Using Magnetic TiO2 and Ti-IMAC  

PubMed Central

Reproducible, comprehensive phosphopeptide enrichment is essential for studying phosphorylation-regulated processes. Here, we describe the application of hyper-porous magnetic TiO2 and Ti-IMAC microspheres for uniform automated phosphopeptide enrichment. Combining magnetic microspheres with a magnetic particle-handling robot enables rapid (45 min), reproducible (r2 ? 0.80) and high-fidelity (>90% purity) phosphopeptide purification in a 96-well format. Automated phosphopeptide enrichment demonstrates reproducible synthetic phosphopeptide recovery across 2 orders of magnitude, “well-to-well” quantitative reproducibility indistinguishable to internal SILAC standards, and robust “plate-to-plate” reproducibility across 5 days of independent enrichments. As a result, automated phosphopeptide enrichment enables statistical analysis of label-free phosphoproteomic samples in a high-throughput manner. This technique uses commercially available, off-the-shelf components and can be easily adopted by any laboratory interested in phosphoproteomic analysis. We provide a free downloadable automated phosphopeptide enrichment program to facilitate uniform interlaboratory collaboration and exchange of phosphoproteomic data sets. PMID:25233145

2014-01-01

223

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

224

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

225

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

226

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

227

Measurements of uranium holdup in an operating gaseous diffusion enrichment plant  

SciTech Connect

Holdup of nuclear material in process equipment is one of the major sources of uncertainty in materials balances, particularly for high-throughput facilities with large equipment and extensive piping, such as gaseous diffusion uranium-enrichment plants. Locating and measuring the holdup while the plant is operating is a challenging problem because of background from the process material and the neighboring equipment. This paper reports NDA measurements performed at the Goodyear Atomic Gaseous Diffusion Plant, Portsmouth, Ohio, on enrichment equipment at the higher enrichment and (>10% /sup 235/U isotopic abundance) of the cascade. Both neutron and gamma-ray measurements were made to locate anomalously large deposits in converters and compressors and, within the limitations of the techniques, to quantify the amount of the deposit.

Augustson, R.H.; Walton, R.B.; Harris, R.; Harbarger, W.; Hicks, J.; Timmons, G.; Shissler, D.; Tayloe, R.; Jones, S.; Fields, L.

1983-01-01

228

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

Microsoft Academic Search

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

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

2012-01-01

229

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

230

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

231

Nutrient enrichment of the subarctic Pacific Ocean pycnocline  

NASA Astrophysics Data System (ADS)

At the end of the global thermohaline circulation, the subarctic Pacific is the richest nutrient repository in the world oceans. Trends towards lower oxygen and higher nutrients in waters below the surface layer (the pycnocline) have been observed in recent decades. We assess these trends using data from four programs and suggest the enrichment of pycnocline nitrate (200 Gmol y-1) is essential in keeping supply to the surface ocean constant, despite increasing upper ocean stratification. A nitrate budget helps identify possible vertical processes that could account for nutrient redistribution. We hypothesize that warming and oxygen loss in the deeper pycnocline, arising from ice loss in the Okhotsk Sea, have initiated a largely vertical redistribution of nutrients due to compression of vertical migrator habitat and/or changes in dissolution of sinking particulates. Coupled climate-ecosystem models will need to incorporate these processes to more fully understand projected changes in the subarctic Pacific.

Whitney, Frank A.; Bograd, Steven J.; Ono, Tsuneo

2013-05-01

232

33 CFR 154.2107 - Inerting, enriching, and diluting systems.  

...concentration reading controls the enriching system and activates...alarm and automatic shutdown...majority pair controls the enriching system and activates...alarm and automatic shutdown...concentration reading controls the diluting system and activates...alarm and automatic...

2014-07-01

233

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

234

21 CFR 137.260 - Enriched corn meals.  

Code of Federal Regulations, 2010 CFR

...DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.260 Enriched corn meals. (a) Enriched...

2010-04-01

235

Inhibitory Action of Tetrathionate Enrichment Broth  

PubMed Central

Tetrathionate enrichment broth is a complex mixture of salts including iodides and other polythionates, but only thiosulfate (0.0736 m) and tetrathionate (0.0236 m) in combination were toxic for Escherichia coli. Individually, these two salts were not lethal. The lethal action of this thiosulfate-tetrathionate mixture affected only growing cells. A possible relationship between the lethality of the thiosulfate-tetrathionate mixture for a culture and its ability to reduce tetrathionate is suggested. PMID:4923809

Palumbo, Samuel A.; Alford, John A.

1970-01-01

236

Turkey liver - a chromium enriched food source  

SciTech Connect

There are presently no known foods for humans that are particularly good sources of chromium. As a means of obtaining Cr enriched foods, turkeys were fed diets containing various levels of supplemental chromium. Four groups of 6-month old turkey hens were fed either the basal diet for laying hens or this diet supplemented with 25, 100 or 200 ..mu..g of chromium as chromium chloride per g of diet. Liver Cr concentration of the turkeys sacrificed after 1 week increased from 7 ng/g (wet wt) while consuming the basal diet to 15, 48 and 68 ng/g, respectively, while consuming the diets with supplemental chromium. Comparable values for the turkeys sacrificed after 5 weeks were 2, 43, 170 and 325 ng/g. Similar trends but higher chromium values were observed for kidney samples. The chromium contents of the dark and white meat and eggs were not altered significantly. Chromium concentrations of the pancreas, gizzard and heart increased marginally; final chromium concentrations were less than 23 ng/g even after 5 weeks on the highest level of supplemental chromium. Chromium content of spleen and lungs was approximately 2-fold higher than that of the pancreas, gizzard or heart. Therefore, turkey liver is a food source suitable for Cr enrichment while the eggs, dark and white meat and other edible parts do not appear to be enriched following chromium supplementation.

Polansky, M.M.; Bryden, N.A.; Richards, M.; Anderson, R.A.

1986-03-01

237

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

Federal Register 2010, 2011, 2012, 2013

...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

238

21 CFR 137.260 - Enriched corn meals.  

...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

239

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

240

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

241

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

242

Enriched Protein-Protein Interactions from Biomedical Text  

E-print Network

Enriched Protein-Protein Interactions from Biomedical Text Barry Haddow, Michael Matthews University of Edinburgh 13th March 2007 Barry Haddow, Michael Matthews Enriched Protein-Protein Interactions from Biomedical Text #12;Overview The TXM Project Protein-Protein Interactions Enriched Protein-Protein

Edinburgh, University of

243

Particle size associated with the surface oxides on low enriched uranium metal plates  

Microsoft Academic Search

Inhalation of respirable particulates of uranium is a radiological concern during the industrial processes used to manufacture nuclear fuels. An investigation of some exposures to Low Enriched Uranium (LEU) indicated that intakes occurred from the inhalation of surface oxide (Uâ, Oâ) particulates covering some LEU metal plates. Measurements of the size distributions of the respirable UâOâ particles were made by

S. H. Linauskas; F. Szostak; A. Trivedi

1996-01-01

244

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

245

RESPONSES OF AGRICULTURAL CROPS TO FREE-AIR CO2 ENRICHMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

The likely effects of future high levels of atmosperic CO2 on several agricultural crops were investiaged. Using literature reports from free-air CO2 enrichment (FACE) experiments, the relative responses of the crops were extracted, tabulated, and analyzed with regard to many plant and soil process...

246

Influence of methane enrichment by aeration of recirculated supernatant on microbial activities during anaerobic digestion  

Microsoft Academic Search

A methane enrichment process (MEP) was evaluated that involved air purging of recycled digester contents to strip CO2 and increase biogas methane content. The objective of this work was to determine if the aeration resulted in oxygen inhibition of microbial activities involved in anaerobic digestion of municipal solid waste. To assess the degree of biological perturbation associated with the MEP,

D. M O'Keefe; R. L Brigmon; D. P Chynoweth

2000-01-01

247

Carbon isotopic enrichment in Titan's Tholins: implications for Titan's aerosols  

NASA Astrophysics Data System (ADS)

Since the discovery of the main composition of Titan s atmosphere many laboratory experiments have been carried out to mimic its chemical evolution and in particular the formation of the haze particles of this atmosphere Indeed the solid products obtained during these simulation experiments -- often named Titan s tholins -- are supposed to be analogues of Titan s aerosols and many studies have already been achieved on these tholins We have studied the possible isotopic fractionation of carbon during the processes involved in the formation of Titan s tholins using tholins obtained from different simulation experiments We will present the first results obtained on the isotopic ratios of 13 C 12 C measured on the analogues of Titan s aerosols synthesized in laboratory Measurement of delta 13 C leaded both on laboratory aerosols and on the initial gas mixture N 2 CH 4 98 2 used in the simulations doesn t show any evident deficit or enrichment of 13 C in comparison with 12 C in the aerosols synthesised compared to the initial gas mixture Preliminary retrieving of the data of the ACP instrument on the Huygens probe suggests that Titan s aerosols may present also no enrichment This allows us to go further in the analyses of the ACP data in comparison with the first conclusions newly published in Nature Isra e l et al Nature 2005

Nguyen, N.; Raulin, R.; Coll, C.; Derenne, D.; Szopa, S.; Israël, I.; Cernogora, C.; Bernard, B.

248

Carbon isotopic enrichment in Titan's tholins? Implications for Titan's aerosols  

NASA Astrophysics Data System (ADS)

Since the discovery of the main composition of Titan's atmosphere, many laboratory experiments have been carried out to reproduce its chemical evolution, particularly the formation of organic haze particles found throughout this atmosphere. Some of these simulations have produced solid products - referred to as Titan's tholins - that are assumed to have properties similar to those of Titan's aerosols. In the present work, we focus on the possible isotopic fractionation of carbon during the processes involved in the formation of Titan's tholins. Initial 12C/ 13C isotopic ratios measured on tholins made in the laboratory using cold plasma discharges are presented. Measurements of isotopic enhancement in 13C ( ?13C), both on tholins and on the initial gas mixture (N 2:CH 4 (98:2)) used to produce them do not show any clear deficit or enrichment in 13C relative to 12C in the lab-made tholins compared to the initial gas mixture. Preliminary data recovered from the Aerosol Collector Pyrolyzer (ACP) experiment of the Huygens probe suggests that Titan's aerosols may also be exempt of carbon isotopic enrichment. This observation creates possibilities for deeper analysis of ACP experiment data.

Nguyen, M.-J.; Raulin, F.; Coll, P.; Derenne, S.; Szopa, C.; Cernogora, G.; Israël, G.; Bernard, J.-M.

2007-11-01

249

Synthesis of Neutron Enriched Heavy and Superheavy Nuclei  

NASA Astrophysics Data System (ADS)

Applicability of different nuclear reactions (fusion of stable and radioactive nuclei, multi-nucleon transfers and neutron capture) for the production of new neutron enriched heavy nuclei is discussed in the paper. For the first time, a narrow pathway is found to the middle of the island of stability owing to possible ?+-decay of SH isotopes which can be formed in ordinary fusion reactions of stable nuclei. Neutron capture reactions can be also used for the production of the long-living neutron rich SH nuclei. Strong neutron fluxes might be provided by pulsed nuclear reactors and by multiple nuclear explosions in laboratory conditions and by supernova explosions in nature. Low-energy multinucleon transfer reactions with actinide beams and targets are of special interest for synthesis of new neutron enriched transfermium nuclei and not-yet-known nuclei around the closed neutron shell N = 126 having largest impact on astrophysical r process. The estimated cross sections for the production of these nuclei look very promising to plan such experiments at available accelerators. Several new test experiments of such kind are proposed to perform including those in which a role of the shell effects in low-energy reaction dynamics could be clarify much better.

Zagrebaev, V. I.; Karpov, A. V.; Greiner, Walter

2014-09-01

250

Paradox of enrichment: A fractional differential approach with memory  

NASA Astrophysics Data System (ADS)

The paradox of enrichment (PoE) proposed by Rosenzweig [M. Rosenzweig, The paradox of enrichment, Science 171 (1971) 385-387] is still a fundamental problem in ecology. Most of the solutions have been proposed at an individual species level of organization and solutions at community level are lacking. Knowledge of how learning and memory modify behavioral responses to species is a key factor in making a crucial link between species and community levels. PoE resolution via these two organizational levels can be interpreted as a microscopic- and macroscopic-level solution. Fractional derivatives provide an excellent tool for describing this memory and the hereditary properties of various materials and processes. The derivatives can be physically interpreted via two time scales that are considered simultaneously: the ideal, equably flowing homogeneous local time, and the cosmic (inhomogeneous) non-local time. Several mechanisms and theories have been proposed to resolve the PoE problem, but a universally accepted theory is still lacking because most studies have focused on local effects and ignored non-local effects, which capture memory. Here we formulate the fractional counterpart of the Rosenzweig model and analyze the stability behavior of a system. We conclude that there is a threshold for the memory effect parameter beyond which the Rosenzweig model is stable and may be used as a potential agent to resolve PoE from a new perspective via fractional differential equations.

Rana, Sourav; Bhattacharya, Sabyasachi; Pal, Joydeep; N'Guérékata, Gaston M.; Chattopadhyay, Joydev

2013-09-01

251

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

252

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

253

Enrichment and depletion of elements in a subbituminous coal and in its 120 C, 400 C, and 800 C ashes  

SciTech Connect

This study reports on the enrichment and depletion of elements in selected suites of subbituminous coals from the Highvale Mine, Alberta, Canada, and in their 120 C, 400 C, and 800 C ashes. All elements analyzed in the raw coal are within the world range for coals, and some small variations in elemental concentration were noted due to variations in ash content of the samples. Ashing at 120 C resulted in an enrichment of all elements by a factor of 1.5--6.5{times} in one suite of samples and by a factor of 5--11{times} in the other suite. Generally, the elements Br and Se are enriched by a lower factor than other elements, Mo is absent in all 120 C ashed samples, and the samples with the higher ash content show a smaller elemental enrichment than samples with lower ash content (cleaner coals). All elements in the 400 C ashed samples are enriched by a factor of 1.5--6.5{times} in one suite of samples and by 1.5--9.5{times} in the other. Surprisingly, the elements Br, Cl, and Se are enriched two- to sixfold, pointing to the possibility of formation of salts (i.e., bromide salts), a process taking place due to the reactions of anions with cations during ashing. By 800 C, the elements Br, Cl, and Mo are completely volatilized. Most elements are enriched by a factor of 5--8{times} in the lower-ash sample and by 2.5--3.5{times} in the higher-ash sample of the first suite, while the enrichment is between 3.5--6{times} in the samples of the second suite. Enrichment factors (EFs) are calculated using the ratio of elemental concentration versus Al concentration in air/crust (method A), and the concentration in ash (method B). Method B should be used when calculating enrichment factors.

Gentzis, T. [Alberta Research Council, Devon, Alberta (Canada). Coal Research Centre Devon; Goodarzi, F. [Geological Survey of Canada, Calgary, Alberta (Canada). Inst. of Sedimentary and Petroleum Geology

1995-01-01

254

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

255

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

256

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

257

Recent advances in enrichment and separation strategies for mass spectrometry-based phosphoproteomics.  

PubMed

Due to the significance of protein phosphorylation in various biological processes and signaling events, new analytical techniques for enhanced phosphoproteomics have been rapidly introduced in the recent years. The combinatorial use of the phospho-specific enrichment techniques and prefractionation methods prior to MS analysis enable comprehensive profiling of the phosphoproteome and facilitate deciphering the critical roles that phosphorylation plays in signaling pathways in various biological systems. This review places special emphasis on the recent five-year (2009-2013) advances for enrichment and separation techniques that have been utilized for phosphopeptides prior to MS analysis. PMID:24687451

Yang, Chenxi; Zhong, Xuefei; Li, Lingjun

2014-12-01

258

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

259

The relative importance of light and nutrient limitation of phytoplankton growth: a simple index of coastal ecosystem sensitivity to nutrient enrichment  

Microsoft Academic Search

Anthropogenic nutrient enrichment of the coastal zone is now a well-established fact. However, there is still uncertainty about the mechanisms through which nutrient enrichment can disrupt biological communities and ecosystem processes in the coastal zone. For example, while some estuaries exhibit classic symptoms of acute eutrophication, including enhanced production of algal biomass, other nutrient-rich estuaries maintain low algal biomass and

James E. Cloern

1999-01-01

260

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

261

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

262

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

263

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

264

Age-dependent effects of environmental enrichment on brain networks and spatial memory in Wistar rats.  

PubMed

We assessed the effect of 3h of environmental enrichment (EE) exposure per day started at different ages (3 and 18months old) on the performance in a spatial memory task and on brain regions involved in the spatial learning (SPL) process using the principal component analysis (PCA). The animals were tested in the four-arm radial water maze (4-RAWM) for 4days, with six daily trials. We used cytochrome c oxidase (COx) histochemistry to determine the brain oxidative metabolic changes related to age, SPL and EE. Behavioural results showed that the enriched groups, regardless of their age, achieved better performance in the spatial task. Interestingly, in the case of the distance travelled in the 4-RAWM, the effect of the EE was dependent on the age, so the young enriched group travelled a shorter distance compared to the aged enriched group. Respect to COx histochemistry results, we found that different brain mechanisms are triggered in aged rats to solve the spatial task, compared to young rats. PCA revealed the same brain functional network in both age groups, but the contribution of the brain regions involved in this network was slightly different depending on the age of the rats. Thus, in the aged group, brain regions involved in anxiety-like behaviour, such as the amygdala or the bed nucleus of the stria terminalis had more relevance; whereas in the young enriched group the frontal and the hippocampal subregions had more contribution. PMID:23769820

Sampedro-Piquero, P; Begega, A; Zancada-Menendez, C; Cuesta, M; Arias, J L

2013-09-17

265

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

266

Selective Recovery of Enriched Uranium from Inorganic Wastes  

SciTech Connect

Uranium as U(IV) and U(VI) can be selectively recovered from liquids and sludge containing metal precipitates, inorganic salts, sand and silt fines, debris, other contaminants, and slimes, which are very difficult to de-water. Chemical processes such as fuel manufacturing and uranium mining generate enriched and natural uranium-bearing wastes. This patented Framatome ANP (FANP) uranium recovery process reduces uranium losses, significantly offsets waste disposal costs, produces a solid waste that meets mixed-waste disposal requirements, and does not generate metal-contaminated liquids. At the head end of the process is a floating dredge that retrieves liquids, sludge, and slimes in the form of a slurry directly from the floor of a lined surface impoundment (lagoon). The slurry is transferred to and mixed in a feed tank with a turbine mixer and re-circulated to further break down the particles and enhance dissolution of uranium. This process uses direct steam injection and sodium hypochlorite addition to oxidize and dissolves any U(IV). Cellulose is added as a non-reactive filter aid to help filter slimes by giving body to the slurry. The slurry is pumped into a large recessed-chamber filter press then de-watered by a pressure cycle-controlled double-diaphragm pump. U(VI) captured in the filtrate from this process is then precipitated by conversion to U(IV) in another Framatome ANP-patented process which uses a strong reducing agent to crystallize and settle the U(IV) product. The product is then dewatered in a small filter press. To-date, over 3,000 Kgs of U at 3% U-235 enrichment were recovered from a 8100 m2 hypalon-lined surface impoundment which contained about 10,220 m3 of liquids and about 757 m3 of sludge. A total of 2,175 drums (0.208 m3 or 55 gallon each) of solid mixed-wastes have been packaged, shipped, and disposed. In addition, 9463 m3 of low-U liquids at <0.001 KgU/m3 were also further processed and disposed.

Kimura, R. T.

2003-02-26

267

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

268

Current methods for phosphoprotein isolation and enrichment.  

PubMed

The phosphorylation of proteins is a central paradigm of signal transduction. The substitution of neutral hydroxyl groups of serine, threonine and tyrosine with a negatively charged phosphate group alters the physicochemical and immunogenic properties of the protein, which then can be used to isolate these isoforms. In the last decades several different techniques were applied, attempting to selectively enrich protein populations with this post-translational modification. This review aims to give an overview on the arsenal of available methods to extract phosphoproteins focusing on chromatographic approaches. PMID:17035107

Schmidt, Stefan R; Schweikart, Fritz; Andersson, Martin E

2007-04-15

269

Mineralization of trichloroethylene by heterotrophic enrichment cultures  

SciTech Connect

Microbial consortia capable of aerobically degrading greater than 99% of 50 mg/l exogenous trichloroethylene (TCE) have been enriched from TCE contaminated subsurface sediments. Concentrations of TCE greater than 300 mg/l were not degraded nor was TCE used as a sole energy source. Successful electron donors for growth included tryptone-yeast extract, methanol, methane or propane. The optimum temperature for growth was 22--37 C and the ph optimum was 7.0--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.

Phelps, T.J.; Ringelberg, D.; Mikell, A.T.; White, D.C. [Univ. of Tennessee, Knoxville, TN (United States). Inst. for Applied Microbiology]|[Oak Ridge National Lab., Knoxville, TN (United States); Fliermans, C.B. [E.I. DuPont de Nemours and Co., Aiken, SC (United States). Savannah River Lab.

1988-12-31

270

Microbial community composition in sediments resists perturbation by nutrient enrichment  

PubMed Central

Functional redundancy in bacterial communities is expected to allow microbial assemblages to survive perturbation by allowing continuity in function despite compositional changes in communities. Recent evidence suggests, however, that microbial communities change both composition and function as a result of disturbance. We present evidence for a third response: resistance. We examined microbial community response to perturbation caused by nutrient enrichment in salt marsh sediments using deep pyrosequencing of 16S rRNA and functional gene microarrays targeting the nirS gene. Composition of the microbial community, as demonstrated by both genes, was unaffected by significant variations in external nutrient supply in our sampling locations, despite demonstrable and diverse nutrient-induced changes in many aspects of marsh ecology. The lack of response to external forcing demonstrates a remarkable uncoupling between microbial composition and ecosystem-level biogeochemical processes and suggests that sediment microbial communities are able to resist some forms of perturbation. PMID:21412346

Bowen, Jennifer L; Ward, Bess B; Morrison, Hilary G; Hobbie, John E; Valiela, Ivan; Deegan, Linda A; Sogin, Mitchell L

2011-01-01

271

Successful brain aging: plasticity, environmental enrichment, and lifestyle  

PubMed Central

Aging is a physiological process that can develop without the appearance of concurrent diseases. However, very frequently, older people suffer from memory loss and an accelerated cognitive decline. Studies of the neurobiology of aging are beginning to decipher the mechanisms underlying not only the physiology of aging of the brain but also the mechanisms that make people more vulnerable to cognitive dysfunction and neurodegenerative diseases. Today we know that the aging brain retains a considerable functional plasticity, and that this plasticity is positively promoted by genes activated by different lifestyle factors. In this article some of these lifestyle factors and their mechanisms of action are reviewed, including environmental enrichment and the importance of food intake and some nutrients. Aerobic physical exercise and reduction of chronic stress are also briefly reviewed. It is proposed that lifestyle factors are powerful instruments to promote healthy and successful aging of the brain and delay the appearance of age-related cognitive deficits in elderly people. PMID:23576888

Mora, Francisco

2013-01-01

272

Uranium enrichment by the separation nozzle method within the framework of German\\/Brazilian cooperation  

Microsoft Academic Search

In the separation nozzle process, the enrichment of ²³⁵U is achieved by extremely high centrifugal forces in a curved flow of UFâ diluted by a light gas. Remarkable progress has been made in the economy of the process by bringing up the gas pressure and by introducing a nozzle system with double deflection of the jet. While the specific energy

E. W. Becker; P. Nogueira Batista; H. Voelcker

1981-01-01

273

Carbon isotopic enrichment in Titan's tholins? Implications for Titan's aerosols  

NASA Astrophysics Data System (ADS)

Since the discovery of the main composition of Titan's atmosphere, many laboratory experiments have been carried out to mimic its chemical evolution, and more particularly the formation of the organic haze particles widespread in this atmosphere. Indeed, some of these simulation experiments produce a solid phase - named Titan's tholins - that is assumed to get properties analogous to the Titan's aerosols ones. We have studied the possible isotopic fractionation of carbon during the processes involved in the formation of Titan's tholins, using tholins obtained from different simulation experiments. It's an important issue because it can provide information on the processes of tholins formation. We will present the first results obtained on the 12 C/13 C isotopic ratios measured on Titan's tholins synthesized in laboratory with cold plasma discharges. Measurements of isotopic enhancement in 13 C (? 13 C), done both on tholins and on the initial gas mixture (N2 :CH4 (98:2)) used to produce them, do not show any clear deficit or enrichment in 13 C relatively to 12 C in the synthesised tholins, compared to the initial gas mixture. Preliminary retrieving of the data of the Aerosol Collector and Pyrolyzer (ACP) experiment of the Huygens probe suggests that Titan's aerosols may also not present carbon isotopic enrichment. This observation allows to go further in the analyses of the ACP experiment data. We are also focusing on the evolution of Titan's tholins under acid hydrolysis treatment. This strong treatment aims to reproduce the evolution of Titan's aerosols in contact with ice water under a longer time scale. Preliminary results on the analyses of the obtained products could give guides lines to identify the still unspecified matter that takes part to the Titan's surface reflectivity decrease as observed by the DISR instrument. This study is still in progress.

Nguyen, M.-J.; Raulin, F.; Coll, P.; Derenne, S.; Szopa, C.; Cernogora, G.; Israel, G.; Bernard, J.-M.

274

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

275

Selective Enrichment of Two Different Types of Nitrospira-like Nitrite-oxidizing Bacteria from a Wastewater Treatment Plant  

PubMed Central

Nitrification is an important step in nitrogen removal in biological wastewater treatment processes. Recently, Nitrospira have been recognized as the numerically dominant nitrite-oxidizing bacterial genus primarily responsible for the second step of aerobic nitrification; however, Nitrospira usually resist cultivation under laboratory conditions and only one species enriched from activated sludge has been described. In this study, a novel enrichment method for Nitrospira was successfully developed using continuous feeding bioreactors. By controlling nitrite concentrations strictly in the bioreactor at low levels below 10 mg-N L?1, coexisting members of sublineages I and II of the genus Nitrospira were enriched selectively. The maximum ratios of sublineages I and II to total microbial cells achieved 88.3% and 53.8%, respectively. This enrichment method is potentially applicable to other uncultured Nitrospira. PMID:23657014

Fujitani, Hirotsugu; Aoi, Yoshiteru; Tsuneda, Satoshi

2013-01-01

276

Fractionation of whey protein isolate with supercritical carbon dioxide to produce enriched ?-lactalbumin and ?-lactoglobulin food ingredients.  

PubMed

An environmentally friendly protein fractionation process using supercritical carbon dioxide (SCO(2)) as an acid was developed to produce enriched ?-lactalbumin (?-LA) and ?-lactoglobulin (?-LG) fractions from whey protein isolate solutions containing from 2 to 10% WPI. This study investigated the effects of pH, temperature, WPI concentration, and residence time on the precipitation kinetics and recovery yields of individual whey proteins and the relative enrichment and composition of both protein fractions. At 5.5-34 MPa and 60-65 °C, solubilized SCO(2) decreased solution pH and induced the formation and precipitation of ?-LA aggregates. Gel electrophoresis and HPLC of the enriched fractions demonstrated the production of ? 60% pure ?-LA, and ? 70% pure ?-LG, under various operating conditions, from WPI containing ?57% ?-LG and 21% ?-LA. The enriched fractions are ready-to-use food ingredients with neutral pH, untainted by acids and contaminants. PMID:22559165

Bonnaillie, Laetitia M; Tomasula, Peggy M

2012-05-23

277

Assuaging Nuclear Energy Risks: The Angarsk International Uranium Enrichment Center  

NASA Astrophysics Data System (ADS)

The recent nuclear renaissance has motivated many countries, especially developing nations, to plan and build nuclear power reactors. However, domestic low enriched uranium demands may trigger nations to construct indigenous enrichment facilities, which could be redirected to fabricate high enriched uranium for nuclear weapons. The potential advantages of establishing multinational uranium enrichment sites are numerous including increased low enrichment uranium access with decreased nuclear proliferation risks. While multinational nuclear initiatives have been discussed, Russia is the first nation to actualize this concept with their Angarsk International Uranium Enrichment Center (IUEC). This paper provides an overview of the historical and modern context of the multinational nuclear fuel cycle as well as the evolution of Russia's IUEC, which exemplifies how international fuel cycle cooperation is an alternative to domestic facilities.

Myers, Astasia

2011-06-01

278

Differential Response of High-Elevation Planktonic Bacterial Community Structure and Metabolism to Experimental Nutrient Enrichment  

PubMed Central

Nutrient enrichment of high-elevation freshwater ecosystems by atmospheric deposition is increasing worldwide, and bacteria are a key conduit for the metabolism of organic matter in these oligotrophic environments. We conducted two distinct in situ microcosm experiments in a high-elevation lake (Emerald Lake, Sierra Nevada, California, USA) to evaluate responses in bacterioplankton growth, carbon utilization, and community structure to short-term enrichment by nitrate and phosphate. The first experiment, conducted just following ice-off, employed dark dilution culture to directly assess the impact of nutrients on bacterioplankton growth and consumption of terrigenous dissolved organic matter during snowmelt. The second experiment, conducted in transparent microcosms during autumn overturn, examined how bacterioplankton in unmanipulated microbial communities responded to nutrients concomitant with increasing phytoplankton-derived organic matter. In both experiments, phosphate enrichment (but not nitrate) caused significant increases in bacterioplankton growth, changed particulate organic stoichiometry, and induced shifts in bacterial community composition, including consistent declines in the relative abundance of Actinobacteria. The dark dilution culture showed a significant increase in dissolved organic carbon removal in response to phosphate enrichment. In transparent microcosms nutrient enrichment had no effect on concentrations of chlorophyll, carbon, or the fluorescence characteristics of dissolved organic matter, suggesting that bacterioplankton responses were independent of phytoplankton responses. These results demonstrate that bacterioplankton communities in unproductive high-elevation habitats can rapidly alter their taxonomic composition and metabolism in response to short-term phosphate enrichment. Our results reinforce the key role that phosphorus plays in oligotrophic lake ecosystems, clarify the nature of bacterioplankton nutrient limitation, and emphasize that evaluation of eutrophication in these habitats should incorporate heterotrophic microbial communities and processes. PMID:21483836

Nelson, Craig E.; Carlson, Craig A.

2011-01-01

279

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

280

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

281

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

282

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

283

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

284

Evaluation of commercially available, wide-pore ultrafiltration membranes for production of ?-lactalbumin-enriched whey protein concentrate.  

PubMed

Commercially available, wide-pore ultrafiltration membranes were evaluated for production of ?-lactalbumin (?-LA)-enriched whey protein concentrate (WPC). In this study microfiltration was used to produce a prepurified feed that was devoid of casein fines, lipid materials, and aggregated proteins. This prepurified feed was subsequently subjected to a wide-pore ultrafiltration process that produced an ?-LA-enriched fraction in the permeate. We evaluated the performance of 3 membrane types and a range of transmembrane pressures. We determined that the optimal process used a polyvinylidene fluoride membrane (molecular weight cut-off of 50 kDa) operated at transmembrane pressure (TMP) of 207 kPa. This membrane type and operating pressure resulted in ?-LA purity of 0.63, ?-LA:?-LG ratio of 1.41, ?-LA yield of 21.27%, and overall flux of 49.46 L/m(2)·h. The manufacturing cost of the process for a hypothetical plant indicated that ?-LA-enriched WPC 80 (i.e., with 80% protein) could be produced at $17.92/kg when the price of whey was considered as an input cost. This price came down to $16.46/kg when the price of whey was not considered as an input cost. The results of this study indicate that production of a commercially viable ?-LA-enriched WPC is possible and the process developed can be used to meet worldwide demand for ?-LA-enriched whey protein. PMID:21338782

Marella, C; Muthukumarappan, K; Metzger, L E

2011-03-01

285

Detection of symmetry-enriched topological phases  

NASA Astrophysics Data System (ADS)

Topologically ordered systems in the presence of symmetries can exhibit new structures which are referred to as symmetry-enriched topological (SET) phases. We introduce simple methods to detect certain SET orders directly from a complete set of topologically degenerate ground-state wave functions. In particular, we first show how to directly determine the characteristic symmetry fractionalization of the quasiparticles from the reduced density matrix of the minimally entangled states. Second, we show how a simple generalization of a nonlocal order parameter can be measured to detect SET phases. The usefulness of the proposed approach is demonstrated by examining two concrete model states which exhibit SET phases: (i) a spin-1 model on the honeycomb lattice and (ii) the resonating valence bond (RVB) state on a kagome lattice. We conclude that the spin-1 model and the RVB state are in the same SET phases.

Huang, Ching-Yu; Chen, Xie; Pollmann, Frank

2014-07-01

286

Deuterium Enrichment of the Interstellar Medium  

E-print Network

Despite low elemental abundance of atomic deuterium in interstellar medium (ISM), observational evidences suggest that several species in gas-phase and in ices could be heavily fractionated. We explore various aspects of deuterium enrichment by constructing a chemical evolution model in gas and grain phases. Depending on various physical parameters, gas and grains are allowed to interact with each other through exchange of their chemical species. It is known that HCO+ and N2H+ are two abundant gas phase ions in ISM and their deuterium fractionation are generally used to predict degree of ionization in various regions of a molecular cloud. To have a more realistic estimation, we consider a density profile of a collapsing cloud. We present radial distributions of important interstellar molecules along with their deuterated isotopomers. We carry out quantum chemical simulation to study effects of isotopic substitution on spectral properties of these important interstellar species. We calculate vibrational (harmo...

Das, Ankan; Chakrabarti, Sandip K; Sahu, Dipen

2014-01-01

287

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

288

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.

289

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

290

Enriched Storable Oxidizers for Rocket Engines  

NASA Technical Reports Server (NTRS)

The name "enriched storable oxidizers" (ESOs) has been coined for a family of optimized mixtures of between two and four oxidizer fluids. For most applications, the constituents of these mixtures would be nitrogen tetroxide (N2O4), nitrous oxide (N2O), and nitrogen dioxide (NO2); in some applications, the mixtures might include inhibited red fuming nitric acid [IRFN (which consists of red fuming nitric acid to which some hydrogen fluoride is added to reduce its corrosive effect]. The optimum proportions of these constituents would be different for different applications. ESOs were originally proposed for use in spacecraft and launch-rocket propulsion systems: ESOs could be especially useful in advanced spacecraft propulsion systems that could operate in multiple modes. ESOs might also be useful in special terrestrial applications that could include ramjet and scramjet aircraft engines.

Sackheim, R. L.; Herdy, J. R., Jr.

2010-01-01

291

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

292

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 5years 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

293

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

294

Following isotopes in pulse-chase enriched aspen seedlings  

NASA Astrophysics Data System (ADS)

One method to quantitatively trace biogeochemical fluxes through ecosystems, such as organic matter decomposition, is to use plant material enriched with stable isotopes. However, as plant macromolecules are known to vary in their rate of formation and decomposition, both the enrichment levels and the location of enrichment within the plant material should be characterized prior to decomposition and tracing studies. Aspen (Populus tremuloides Michx.) is a common tree species with a diverse organic matter chemical structure found in the western Canadian boreal forest. This study used a multi pulse and multi chase enrichment of stable isotopes (15N and 13C) on aspen seedlings to determine the seedling enrichment, isotope movement among plant tissues and translocation of isotopes within plant macromolecules e.g., carbohydrates and lignin. As expected, all tissues experienced increased enrichment with multiple pulses. An initial enrichment with 13C was observed in the leaves followed by translocation to the stems and roots while the 15N moved upward from the roots to leaves. The macromolecular chemistry of the organic carbon was further characterized using 13C solid state nuclear magnetic resonance spectroscopy. After the initial two hour chase period enrichment of the O-alkyl type (carbohydrate) carbon within the leaves was identified, followed by redistribution to more complex carbon compounds after the one week chase period. Root and stem tissues did not show the same pattern. Rather, changes in 13C enrichment were observed in shifting ethyl and methyl alkyl (lipid) carbon peak intensities for the stem samples while roots did not preferentially allocate 13C to a specific macromolecule. These results confirm that stable isotope enrichment of plants was non-uniform across macromolecules and tissue types. Enrichment of aspen seedlings was therefore dependant on the pulse-chase sequence used.

Norris, C. E.; Wasylishen, R. E.; Landhäusser, S.; Quideau, S. A.

2011-12-01

295

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

296

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

297

Effect of oxygen enrichment on morphology, growth, and heterologous protein production in chemostat cultures of Aspergillus niger B1-D.  

PubMed

The response of steady state chemostat cultures of a recombinant Aspergillus niger (B1-D), secreting both a heterologous enzyme (Hen Egg White Lysozyme [HEWL]) and a native enzyme (Glucoamylase), to varying levels of O2 enrichment of the process gas was evaluated. Formation of both the native and the foreign enzyme increased with increasing O2 supply. Conversely, biomass levels and total extracellular protein levels were generally not increased under O2 enriched conditions. Two distinct micromorphologies were apparent in these cultures, one, typically seen under O2 limiting conditions (i. e. at 0 and 10% enrichment levels), tended to be represented by long, sparsely branched hyphal elements, with low percentages of "active" length (i. e. how much of the hypha is cytoplasm filled); whilst, a second micromorphology, typical of O2 enriched cultures at 30 and 50% O2 enrichment, was represented by shorter hyphal elements, with more branching and a higher % "active" length. At these higher O2 levels, formation of a yellow pigment occurred, and signs of culture autolysis were noted. At 50% enrichment, a "stranded" aggregate morphology was apparent, possibly as a response to a hyperoxidant state. Production of both the native enzyme and HEWL correlated well with a simple morphological measure (tip number) or, with % "active" length. It is proposed the morphological changes noted in the cultures were associated with the increased production of both HEWL and glucoamylase. PMID:10506417

Wongwicharn, A; McNeil, B; Harvey, L M

1999-11-20

298

Air-Xe enrichments in Elk Hills oil field gases: role of water in migration and storage  

NASA Astrophysics Data System (ADS)

Hydrocarbons from the Elk Hills Naval Petroleum Reserve (NPR#1), Bakersfield, CA, are enriched in heavy noble gases. The 132Xe/ 36Ar ratios are as high as ˜576 times the ratio in air and represent the largest relative Xe-enrichments ever observed in terrestrial fluids. The Xe isotopic composition is indistinguishable from air. We show that these samples cannot be explained by equilibration of oil with air saturated water and secondary enrichment via a Rayleigh distillation gas stripping process. Based on laboratory studies of others with potential petroleum source rocks, we believe the source of this enriched heavy noble gas component was adsorbed air initially trapped in/on the source rocks that was expelled and mixed with the hydrocarbons during expulsion and primary migration. Kr and Xe enrichments decrease with increasing 36Ar concentration. We propose a model in which an initial Kr-Xe-enriched hydrocarbon becomes diluted with noble gases extracted from air saturated groundwater during expulsion, migration, and storage. The model generates an integrated water/hydrocarbon ratio for the production fluid which indicates a minimal role for water in hydrocarbon expulsion and migration. The results are interpreted to provide time/geometrical constraints on the mechanisms by which hydrocarbons can migrate as a separate phase.

Torgersen, T.; Kennedy, B. M.

1999-04-01

299

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

300

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

301

Construction of Trypanosoma brucei Illumina RNA-Seq libraries enriched for transcript ends.  

PubMed

High-throughput RNA sequencing (RNA-Seq) has quickly occupied center stage in the repertoire of available tools for transcriptomics. Among many advantages, the single-nucleotide resolution of this powerful approach allows mapping on a genome-wide scale of splice junctions and polyadenylation sites, and thus, the precise definition of mature transcript boundaries. This greatly facilitated the transcriptome annotation of the human pathogen Trypanosoma brucei, a protozoan organism in which all mRNA molecules are matured by spliced leader (SL) trans-splicing from longer polycistronic precursors. The protocols described here for the generation of three types of libraries for Illumina RNA-Seq, 5'-SL enriched, 5'-triphosphate-end enriched, and 3'-poly(A) enriched, enabled the discovery of an unprecedented heterogeneity of pre-mRNA-processing sites, a large number of novel coding and noncoding transcripts from previously unannotated genes, and quantify the cellular abundance of RNA molecules. The method for producing 5'-triphosphate-end-enriched libraries was instrumental for obtaining evidence that transcription initiation by RNA polymerase II in trypanosomes is bidirectional and biosynthesis of mRNA precursors is primed not only at the beginning of unidirectional gene clusters, but also at specific internal sites. PMID:25388113

Kolev, Nikolay G; Ullu, Elisabetta; Tschudi, Christian

2015-01-01

302

Preparation of titanium-grafted magnetic mesoporous silica for the enrichment of endogenous serum phosphopeptides.  

PubMed

As one of the most important post-translational modifications, reversible phosphorylation of protein plays crucial roles in a large number of biological processes. Moreover, endogenous phosphopeptides are also associated with certain human diseases. An efficient enrichment and separation method is the premise for successful identification and quantification of phosphopeptides. In this work, titanium grafted magnetic mesoporous silica (Fe3O4@Ti-mSiO2) was developed and applied for the enrichment of endogenous phosphopeptides. Fe3O4@Ti-mSiO2 particles were prepared by grafting titanocene dichloride on the inner walls of magnetic mesoporous silica and then being calcined to remove cyclopentadienyl ligand. The physicochemical properties of the prepared materials were characterized by energy dispersive X-ray spectroscopy (EDX), nitrogen adsorption-desorption analysis, X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). For selective enrichment of phosphopeptides, the prepared Fe3O4@Ti-mSiO2 particles were applied for tryptic digests of ?-casein, mixtures of ?-casein and bovine serum albumin (BSA), and low-fat milk. Finally, Fe3O4@Ti-mSiO2 was successfully applied for the enrichment of endogenous phosphopeptides from human serum. PMID:24090595

Li, Xiao-Shui; Pan, Ya-Ni; Zhao, Yong; Yuan, Bi-Feng; Guo, Lin; Feng, Yu-Qi

2013-11-01

303

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

304

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

305

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

306

33 CFR 154.824 - Inerting, enriching, and diluting systems.  

Code of Federal Regulations, 2012 CFR

...concentration reading controls the inerting or enriching system and activates...alarm and automatic shutdown...concentration reading controls the enriching system and activates...alarm and automatic shutdown...concentration reading controls the diluting system and activates...alarm and automatic...

2012-07-01

307

33 CFR 154.824 - Inerting, enriching, and diluting systems.  

Code of Federal Regulations, 2011 CFR

...concentration reading controls the inerting or enriching system and activates...alarm and automatic shutdown...concentration reading controls the enriching system and activates...alarm and automatic shutdown...concentration reading controls the diluting system and activates...alarm and automatic...

2011-07-01

308

33 CFR 154.824 - Inerting, enriching, and diluting systems.  

Code of Federal Regulations, 2013 CFR

...concentration reading controls the inerting or enriching system and activates...alarm and automatic shutdown...concentration reading controls the enriching system and activates...alarm and automatic shutdown...concentration reading controls the diluting system and activates...alarm and automatic...

2013-07-01

309

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

310

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

311

Charles R. Spain Career Enrichment Center, Delivery of Services Evaluation.  

ERIC Educational Resources Information Center

The Career Enrichment Center (CEC) provides a year-round, voluntary career education program for all Albuquerque high school students. It offers courses; provides special services; manages and coordinates enrichment opportunities, alternate programs, and satellite stations; and provides liaison with businesses, community, and universities. This…

McDaniel, Patrick L.

312

Enrichment Materials in Home Economics for Gifted and Talented Students.  

ERIC Educational Resources Information Center

Designed to provide the home economics teacher with a resource of enrichment materials for gifted/talented students, this manual consists of information to assist home economics teachers and students in designing enrichment materials to supplement classroom learning and suggested learning activities in five home economics areas. Part 1 of the…

Arkansas State Dept. of Education, Little Rock. Div. of Vocational, Technical and Adult Education.

313

Chest wall thickness measurements for enriched uranium: An alternative approach  

Microsoft Academic Search

Human Monitoring Laboratory has developed a technique to determine the chest wall thickness of an individual using information from the spectrum produced by internally deposited radionuclides. The technique has been investigated both theoretically and practically using phoswich detectors and the Lawrence Livermore Torso Phantom. The phantom was used with lung sets containing homogeneously distributed 93% enriched uranium, 20% enriched uranium,

Gary H. Kramer; Mirela Puscalau

1994-01-01

314

Safeguards training course: Nuclear material safeguards for enrichment plants  

SciTech Connect

The main objective of this course is to provide the course participants with the necessary skills to perform their inspection activities at enrichment plants. As background information, a variety of enrichment technologies will first be characterized and compared followed by a review of basic cascade, gas centrifuge, and gaseous diffusion theory. To focus on gas centrifuge and gaseous diffusion technology, the major components and system of gas centrifuge and gaseous diffusion enrichment plants including their function in routine LEU production will be identified. The objectives of safeguards at an enrichment plant, including those agreed to in the Hexapartite Safeguards Project, will then be described. Discussions will then focus on potential diversion scenarios at both a centrifuge and diffusion enrichment facility and applicable safeguards inspection activities for detecting these scenarios. This report presents a discussion on basic separation and cascade theory, uranium hexafluoride, and detailed separation theory, including gas centrifuge and gaseous diffusion.

Not Available

1990-06-01

315

Omega-3-enriched broiler meat: 2. Functional properties, oxidative stability, and consumer acceptance.  

PubMed

Consumers are becoming more aware of the impact on their health of the food they eat. One of the ways they hope to reduce their risk of cardiovascular disease is by consuming more foods enriched with polyunsaturated fatty acids (PUFA), particularly n-3 fatty acids. Flaxseed is a good source for increasing the n-3 PUFA in poultry meat because of the high content of alpha-linolenic acid. A study was conducted to identify an optimal process to enrich of broiler diets with n-3 PUFA by using 2 levels of flaxseed fed for various times before processing. The acceptability of broiler meat functional properties was tested to ensure that further processing efficiencies would not be compromised by the enrichment strategy. This experiment was conducted as a 2 x 8 factorial, with 2 dietary levels of ground flaxseed (10 and 17%) fed for 8 lengths of time before processing [0 (control), 4, 8, 12, 16, 20, 24, and 35 d]. Of 650 Ross x Ross 308 mixed-sex broilers reared in this study, 128 were used to evaluate breast and thigh meat functional properties, oxidative stability, and sensory analysis. No statistical interactions were found between treatments for chicken breast meat quality traits. The duration of feeding flaxseed strongly affected meat quality parameters. In particular, feeding flaxseed for 16 d resulted in a final pH of 5.65, compared with 5.93 in the control. The lower ultimate pH found in animals fed flaxseed affected meat cooking loss, drip loss, and shear value (P < 0.0001). Shear value significantly increased after 16 d of feeding flaxseed (P < 0.0001). Susceptibility to oxidation increased in both breast and thigh broiler meat with the duration of feeding flaxseed. Enriching the diet for less than 16 d did not result in perceivable sensory defects. Duration of flaxseed feeding significantly affected the color characteristics, functional properties, and oxidative stability of broiler meat. PMID:19359699

Betti, M; Schneider, B L; Wismer, W V; Carney, V L; Zuidhof, M J; Renema, R A

2009-05-01

316

[Vitamin and mineral enrichment of wheat flour of the high and first class quality].  

PubMed

Norms of inclusion of vitamins (B1; B2; PP) and mineral substances (Ca and Fe) in high and first-rate wheat's flour were defined. Vitamin's contents were verified and composed balance of vitamins and mineral substances contents in different stages of technology process. It was established efficacy of enrichment of wheat's flour with vitamin-mineral mixture to production as fast as possible, particularly in regions of Chernobil's accident and also in regions with ferrum deficiency. PMID:7871777

Igorianova, N A; Shukhnov, A F; Spirichev, V B; Ivanov, A A; Fadina, I V; Guseva, L I; Meandrova, S B; Shatniuk, L N

1994-01-01

317

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

318

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

319

Adaptive enrichment designs for clinical trials  

PubMed Central

Modern medicine has graduated from broad spectrum treatments to targeted therapeutics. New drugs recognize the recently discovered heterogeneity of many diseases previously considered to be fairly homogeneous. These treatments attack specific genetic pathways which are only dysregulated in some smaller subset of patients with the disease. Often this subset is only rudimentarily understood until well into large-scale clinical trials. As such, standard practice has been to enroll a broad range of patients and run post hoc subset analysis to determine those who may particularly benefit. This unnecessarily exposes many patients to hazardous side effects, and may vastly decrease the efficiency of the trial (especially if only a small subset of patients benefit). In this manuscript, we propose a class of adaptive enrichment designs that allow the eligibility criteria of a trial to be adaptively updated during the trial, restricting entry to patients likely to benefit from the new treatment. We show that our designs both preserve the type 1 error, and in a variety of cases provide a substantial increase in power. PMID:23525452

Simon, Noah; Simon, Richard

2013-01-01

320

Group sequential enrichment design incorporating subgroup selection.  

PubMed

An important component of clinical trials in drug development is the analysis of treatment efficacy in patient subgroups (subpopulations). Because of concerns of multiplicity and of the small sample sizes often involved, such analyses can present substantial statistical challenges and may lead to misleading conclusions. As a confirmatory seamless phase II/III design, we propose an adaptive enrichment group sequential procedure whereby resources can be concentrated on subgroups most likely to respond to treatment. Stopping boundaries are defined through upper and lower spending functions. The procedure is presented in terms of the efficient score, enabling the analysis of normal, binary, or time-to-event data. It addresses the dilution effect by eliminating populations at the first stage that appear likely to derive no therapeutic benefit. It subsequently proceeds with the definitive assessment of treatment efficacy among the remaining pooled populations using a group sequential design. The procedure provides strong protection of familywise type I error rate, and we employ a bootstrap algorithm to obtain point and interval estimates that are adjusted for the selection bias. We give examples to demonstrate how the design is used. We make comparisons with adaptive two-stage combination test procedures and with a group sequential test that does not account for the presence of subgroups. Numerical results show that the procedure has high power to detect subgroup-specific effects and the use of multiple interim analysis points can lead to substantial sample size savings. PMID:23315698

Magnusson, Baldur P; Turnbull, Bruce W

2013-07-20

321

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

322

Stable isotope enrichment using a plasma centrifuge  

NASA Astrophysics Data System (ADS)

A primary goal of the Department of Energy's Isotope Development and Production for Research and Applications Program (Isotope Program) within the Office of Nuclear Physics (NP) is to produce isotopes that are in short supply in the U.S. and of which there exists no or insufficient domestic commercial production capability. A vacuum arc plasma centrifuge is a rigid rotor column of metal plasma in which centrifugal forces re-distribute ions radially according to their mass/charge ratio. Early work demonstrated rotation at 2 million rpm and separation of various stable isotopes. The spinning plasma column had a Gaussian flux profile, peaked on the rigid rotor axis. This work adopts a more efficient approach, with the plasma created as a hollow column, wherein the flux is concentrated at larger radii where the centrifugal action is highest. By tailoring the vacuum arc discharge geometry, the rotation rate can also be increased to ˜10 million rpm. Data from Cu, Al and other metal plasmas will be presented and discussed in light of enriched stable isotopes needed for research and medicine.

Krishnan, Mahadevan; Bures, Brian; Madden, Robert

2012-10-01

323

Salt Enrichment of Municipal Sewage: New Prevention Approaches in Israel  

PubMed

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 water-softening 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 NaCl solution, a reduction of the discharge of salts by the meat koshering process, and new membrane technology for salt recovery. PMID:8661617

Weber; Avnimelech; Juanico

1996-07-01

324

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

325

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

326

Development of an enrichment monitor for the Portsmouth GCEP  

SciTech Connect

We have developed a gas-phase UF/sub 6/ enrichment monitor for use by the International Atomic Energy Agency at the Portsmouth Gas Centrifuge Enrichment Plant. The enrichment monitoring system provides a method for effective nuclear materials accountability verification while reducing the effort for both the facility operator and the inspector. The experience with an inplant prototype monitor, the facility and operational constraints, and the constraints related to international safeguards inspection are described in terms of the impact on the monitor design.

Strittmatter, R.B.; Stovall, L.A.; Sprinkle, J.K. Jr.

1983-01-01

327

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

328

Nanoscience and Nanotechnology Concepts for Enriching High School Curricula  

NASA Astrophysics Data System (ADS)

High school science teachers seeking to enhance student enthusiasm for science and to enrich their curricula with ``real world'' examples might be interested in drawing on nanoscience, which is currently a major branch of study in biology, chemistry, and physics---key high school curriculum areas---and is also a subject much reported upon by the news media. However, presenting nanoscience and nanotechnology in the classroom presents key challenges: the subject matter must be successfully integrated into the core curriculum so as to enhance the students' educational experience; it must support the aims of Texas Essential Knowledge and Skills for Science (TEKC), or equivalent systems in other states; it must be made accessible to students; and it must be presentable with the use of equipment or supplies that are neither too expensive nor too rare to be obtainable by school districts. These last two requirements are particularly difficult, because it is the nature of nanoscale research that complex fabrication processes and expensive characterization methods are typically required. This talk will discuss the authors' experience leading a teachers' workshop session in 2009 to address the issue of introducing nanoscience into the high school science classroom. The workshop is funded by the NSF through the UT-IGERT program, and brings together teachers from across Texas annually for discussion, curriculum-building, and training in concepts related to nanoscience and nanotechnology.

Sanders, Charlotte; Marshall, Jill

2010-03-01

329

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

330

77 FR 1059 - Low Enriched Uranium From France: Initiation of Antidumping Duty Changed Circumstances Review  

Federal Register 2010, 2011, 2012, 2013

...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

331

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

...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

332

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

333

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

... 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

334

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

Federal Register 2010, 2011, 2012, 2013

...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

335

77 FR 19642 - Low Enriched Uranium From France: Final Results of Antidumping Duty Changed Circumstances Review  

Federal Register 2010, 2011, 2012, 2013

...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

336

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

337

3 CFR - Continuation of the National Emergency With Respect to the Disposition of Russian Highly Enriched...  

...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

338

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

339

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

340

77 FR 7128 - Low Enriched Uranium From France: Preliminary Results of Antidumping Duty Changed Circumstances...  

Federal Register 2010, 2011, 2012, 2013

...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

341

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

342

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

Federal Register 2010, 2011, 2012, 2013

...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

343

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

344

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

345

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

346

A first principles approach to supergene enrichment of a porphyry copper protore: I. Cu-Fe-S subsystem  

Microsoft Academic Search

A unified description of supergene enrichment of a porphyry copper protore is presented based on the principles of metasomatic zoning. Mathematically this formulation represents the supergene weathering process as a moving boundary problem. A first principles approach is used to describe quantitatively the transport of oxygenated water through a porous host rock consisting of a Cu-bearing protore. Mineral reaction rates

Peter C. Lichtner; Giuseppe G. Biino

1992-01-01

347

Tornado extraction: A method to enrich and purify RNA from the nephrogenic zone of the neonatal rat kidney  

Microsoft Academic Search

Tornado extraction: A method to enrich and purify RNA from the nephrogenic zone of the neonatal rat kidney.BackgroundDevelopment of the kidney is a complicated and tightly regulated process. Although several genes responsible for the renal development have been identified to date, the precise mechanisms of spatial and temporal regulation remain to be elucidated. Therefore, expanding our knowledge of molecules that

Takahito Ito; Akira Suzuki; Enyu Imai; Naoko Horimoto; Tomokazu Ohnishi; Yasushi Daikuhara; Masatsugu Hori

2002-01-01

348

Sorption behaviour of nutrients in loamy-sand bioretention media subject to different conditions (vegetation, enrichment and incubation time)  

Microsoft Academic Search

Sorption is expected to be an important process in nutrient removal from stormwater by bioretention systems. The sorption capacity of loamy-sand media from experimental bioretention mesocosms with and without vegetation and prior nutrient enrichment was tested, using two incubation times (24 hours or 72 hours) and nutrient solutions comprising ammonium, organic nitrogen, phosphate, organic phosphorus, and organic carbon, at concentrations

Courtney Henderson; Margaret Greenway; Ian Phillips

349

Chemical enrichment and physical conditions in I Zw 18  

NASA Astrophysics Data System (ADS)

Context. 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 objective is to constrain the spatial- and time-scales over which the H i 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, C ii, C ii*, N i, O i, ...) 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 H i 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 ~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? (vs. 1/31 Z? 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 H0 atoms in the diffuse neutral gas. We calculate the star-formation rate from the C ii* 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 (~2000 times lower than the Milky Way value). Appendix A is available in electronic form at http://www.aanda.org

Lebouteiller, V.; Heap, S.; Hubeny, I.; Kunth, D.

2013-05-01

350

Origin of the Deuterium Enrichment in the Solar System  

NASA Astrophysics Data System (ADS)

The present-day D/H ratio of the solar system is well known. In meteorites, water is under the form of -OH bearing minerals with D/H ratio lying in the range 140.10^-6 to 180.10^-6. On the Earth, the D/H ratio of water is close to 155.10^-6. Such a value demonstrates clearly the common origin of water on Earth and in meteorites. The giant planets, which are assumed to have kept the primordial molecular hydrogen from the protosolar nebula have a ratio close to 30.10^-6. The aim of the present work is to determine if it is possible to obtain, via isotopic exchange processes, a meteorite-like D/H ratio during the life-time of the nebula. Thus isotopic exchange rate constants for the hydrogen-water and hydrogen-methane reactions were measured: HD + H2O <--> H2 + HDO & HD + CH4 <--> H2 + CH3D D2O-H2 and CD4-H2 mixtures were prepared at several temperatures and pressures. After the reaction, molecular hydrogen is separated cryogenically from CD4 or D2O. Hydrogen is analyzed by mass spectrometry. The duration and the temperature of these experiments permit a precise determination of the rate constants. Catalytic effects were also studied, on SiO2, clays and organic polymers: exchange rates do not markedly increase relative to those determined without catalysts. Based on our present data, several numerical applications to the nebula were performed using Cameron's model [1] with the following parameters: total H2 pressure in the nebula between 10^-3 and 10^-4 atm for 1 to 3 A.U.; life-time of the nebula: 30 m.y.; maximum temperature reached by the nebula: 1300 K; cooling rate: t(sub)1/2 ranging from 3 to 6.10^6 years; initial D/H ratio in hydrogen: 30.10^-6. These calculations led us to the following conclusions: 1) Deuterium exchange with CH4 is always slower than with H2O. 2) The maximum deuterium enrichment depends markedly on the total pressure in the nebula. 3) Deuterium enrichments similar to those measured in carbonaceous chondrites can be reached for distances from the Sun >= 2 A.U. Therefore, as suggested 20 years ago [2], the origin of the deuterium enrichment in meteorites and in the terrestrial oceans is satisfactorily accounted for by a simple model of isotope exchange in the solar nebula. References: [1] Cameron, (1972) Symposium on the origin of the Solar System-Nice. [2] Geiss & Reeves, (1972) Astron. Astrophys., 18, 126-132.

Lecluse, C.; Robert, F.

1992-07-01

351

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

352

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

353

Integrated microscale analysis system for targeted liquid chromatography mass spectrometry proteomics on limited amounts of enriched cell populations.  

PubMed

Limited samples, such as those that are in vivo sourced via biopsy, are closely representative of biological systems and contain valuable information for drug discovery. However, these precious samples are often heterogeneous and require cellular prefractionation prior to proteomic analysis to isolate specific subpopulations of interest. Enriched cells from in vivo samples are often very limited (<10(4) cells) and pose a significant challenge to proteomic nanoliquid chromatography mass spectrometry (nanoLCMS) sample preparation. To enable the streamlined analysis of these limited samples, we have developed an online cell enrichment, microscale sample preparation, nanoLCMS proteomics workflow by integrating fluorescence activated cell sorting (FACS), focused ultrasonication, microfluidics, immobilized trypsin digestion, and nanoLCMS. To assess the performance of the online FACS-Chip-LCMS workflow, 5000 fluorescent labeled cells were enriched from a 5% heterogeneous cell population and processed for LCMS proteomics in less than 2 h. Within these 5000 enriched cells, 30 peptides corresponding to 17 proteins spanning more than 4 orders of magnitude of cellular abundance were quantified using a QExactive MS. The results from the online FACS-Chip-LCMS workflow starting from 5000 enriched cells were directly compared to results from a traditional macroscale sample preparation workflow starting from 2.0 × 10(6) cells. The microscale FACS-Chip-LCMS workflow demonstrated high cellular enrichment efficiency and high peptide recovery across the wide dynamic range of targeted peptides. Overall the microscale FACS-Chip-LCMS workflow has shown effectiveness in efficiently preparing limited amounts of FACS enriched cells in an online manner for proteomic LCMS. PMID:24083476

Martin, Jeffrey G; Rejtar, Tomas; Martin, Stephen A

2013-11-19

354

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

355

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

356

Highly efficient chiral resolution of DL-arginine by cocrystal formation followed by recrystallization under preferential-enrichment conditions.  

PubMed

An excellent chiral symmetry-breaking spontaneous enantiomeric resolution phenomenon, denoted preferential enrichment, was observed on recrystallization of the 1:1 cocrystal of dl-arginine and fumaric acid, which is classified as a racemic compound crystal with a high eutectic ee value (>95?%), under non-equilibrium crystallization conditions. On the basis of temperature-controlled video microscopy and in situ time-resolved solid-state (13) C?NMR spectroscopic studies on the crystallization process, a new mechanism of phase transition that can induce preferential enrichment is proposed. PMID:25042834

Iwama, Sekai; Kuyama, Kazunori; Mori, Yuko; Manoj, Kochunnoonny; Gonnade, Rajesh G; Suzuki, Katsuaki; Hughes, Colan E; Williams, P Andrew; Harris, Kenneth D M; Veesler, Stéphane; Takahashi, Hiroki; Tsue, Hirohito; Tamura, Rui

2014-08-11

357

PREPARING THE HIGH FLUX ISOTOPE REACTOR FOR CONVERSION TO LOW ENRICHED URANIUM FUEL ? RETURN TO 100 MW  

SciTech Connect

The feasibility of low-enriched uranium (LEU) fuel as a replacement for the current, high enriched uranium (HEU) fuel for the High Flux Isotope Reactor (HFIR) has been under study since 2006. Reactor performance studies have been completed for conceptual plate designs and show that maintaining reactor performance while converting to LEU fuel requires returning the reactor power to 100 MW from 85 MW. The analyses required to up-rate the reactor power and the methods to perform these analyses are discussed. Comments regarding the regulatory approval process are provided along with a conceptual schedule.

Smith, Kevin Arthur [ORNL; Primm, Trent [ORNL

2009-01-01

358

Building Science Process Skills  

NSDL National Science Digital Library

A well-designed and executed field trip experience serves not only to enrich and supplement course content, but also creates opportunities to build basic science process skills. This article describes an onsite trip to the Bronx Zoo that allowed collaborating students to develop acquisitive and organizational skills while exploring rain forest habitat characteristics and species diversity.

Anthony V. DeFina

2006-01-01

359

Looking North into Lab Metallurgy Testing Area and Enrichment Motor ...  

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

Looking North into Lab Metallurgy Testing Area and Enrichment Motor within Recycle Recovery Building - Hematite Fuel Fabrication Facility, Recycle Recovery Building, 3300 State Road P, Festus, Jefferson County, MO

360

Typing Keys Unlock the Doors to Reading Enrichment  

ERIC Educational Resources Information Center

The use of typewriting as a way to reading and language enrichment on the elementary level is discussed and illustrated through reviews of several studies showing practical uses of the typewriter in the overall language arts program. (MF)

Seltzer, Ronald; Seltzer, Dianne

1978-01-01

361

Enrichment medium for isolation of Campylobacter jejuni-Campylobacter coli.  

PubMed

A kaseini-broth enrichment medium (KBEM) for the isolation improvement of Campylobacter jejuni-Campylobacter coli from stool samples is described. Isolation of Campylobacters from stool specimens by direct inoculation onto solid selective medium was compared with isolation after twenty-four hours enrichment at 37 degrees C in KBEM, followed by subculture onto the same solid selective medium. Of 156 examined stool samples from diarrhoeal children positive results were obtained from 17 patients altogether: 11 by direct inoculation on selective media and 6 only owing to enrichment. Thus, an increase of 35.3% in the isolation rate was obtained by using the enrichment medium. The same medium allows the preservation of isolates of Campylobacter jejuni-Campylobacter coli for 2 months and longer at 37 degrees C. PMID:9524671

Sicinschi, L A

1995-01-01

362

Reproducing kernel element method Part III: Generalized enrichment and applications  

E-print Network

Reproducing kernel element method Part III: Generalized enrichment and applications Hongsheng Lu finite element methods, the construction proposed here has more flexibility and only needs minimal degrees of freedom. The optimal element with high reproducing capacity and overall minimal degrees

Li, Shaofan

363

The uranium cylinder assay system for enrichment plant safeguards  

SciTech Connect

Safeguarding sensitive fuel cycle technology such as uranium enrichment is a critical component in preventing the spread of nuclear weapons. A useful tool for the nuclear materials accountancy of such a plant would be an instrument that measured the uranium content of UF{sub 6} cylinders. The Uranium Cylinder Assay System (UCAS) was designed for Japan Nuclear Fuel Limited (JNFL) for use in the Rokkasho Enrichment Plant in Japan for this purpose. It uses total neutron counting to determine uranium mass in UF{sub 6} cylinders given a known enrichment. This paper describes the design of UCAS, which includes features to allow for unattended operation. It can be used on 30B and 48Y cylinders to measure depleted, natural, and enriched uranium. It can also be used to assess the amount of uranium in decommissioned equipment and waste containers. Experimental measurements have been carried out in the laboratory and these are in good agreement with the Monte Carlo modeling results.

Miller, Karen A [Los Alamos National Laboratory; Swinhoe, Martyn T [Los Alamos National Laboratory; Marlow, Johnna B [Los Alamos National Laboratory; Menlove, Howard O [Los Alamos National Laboratory; Rael, Carlos D [Los Alamos National Laboratory; Iwamoto, Tomonori [JNFL; Tamura, Takayuki [JNFL; Aiuchi, Syun [JNFL

2010-01-01

364

ALCHEMIST (Adjuvant Lung Cancer Enrichment Marker Identification and Sequencing Trials)  

Cancer.gov

August 2014 ALCHEMIST (Adjuvant Lung Cancer Enrichment Marker Identification and Sequencing Trials) 3 Integrated Trials Testing Targeted Therapy in Early Stage Lung Cancer Part of NCI’s Precision Medicine Effort in Cancer NCI National Clinical

365

21 CFR 137.160 - Enriched bromated flour.  

Code of Federal Regulations, 2010 CFR

...2010-04-01 false Enriched bromated flour. 137.160 Section 137.160 ...FOOD FOR HUMAN CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.160...

2010-04-01

366

Indicator displacement assays that detect bilayer membranes enriched in phosphatidylserine  

E-print Network

Indicator displacement assays that detect bilayer membranes enriched in phosphatidylserine Roger G: 10.1039/b500522a Three indicator displacement assays are described for the detection selectively to the phosphatidylserine and act as a colorimetric chemosensing ensemble when combined

Smith, Bradley D.

367

Free-Air CO2 Enrichment (FACE) Research Sites  

NSDL National Science Digital Library

FACE, the Free Air Carbon Dioxide Enrichment research program of Brookhaven National Laboratory, provides data summaries on a variety of FACE sites: North Carolina, Nevada, Wisconsin, and Brauschweig (Germany). To access more detailed information, follow links to specific sites.

1969-12-31

368

RERTR 2009 (Reduced Enrichment for Research and Test Reactors)  

SciTech Connect

The U.S. Department of Energy/National Nuclear Security Administration's Office of Global Threat Reduction in cooperation with the China Atomic Energy Authority and International Atomic Energy Agency hosted the 'RERTR 2009 International Meeting on Reduced Enrichment for Research and Test Reactors.' The meeting was organized by Argonne National Laboratory, China Institute of Atomic Energy and Idaho National Laboratory and was held in Beijing, China from November 1-5, 2009. This was the 31st annual meeting in a series on the same general subject regarding the conversion of reactors within the Global Threat Reduction Initiative (GTRI). The Reduced Enrichment for Research and Test Reactors (RERTR) Program develops technology necessary to enable the conversion of civilian facilities using high enriched uranium (HEU) to low enriched uranium (LEU) fuels and targets.

Totev, T.; Stevens, J.; Kim, Y. S.; Hofman, G.; Matos, J.; Hanan, N.; Garner, P.; Dionne, B.; Olson, A.; Feldman, E.; Dunn, F.; Nuclear Engineering Division; Atomic Research Center; Inst. of Nuclear Physics; LLNL; INL; Korea Atomic Energy Research Inst.; Comisi?n Nacional de Energ?a At?mica; Nuclear Reactor Lab.; Inst. of Atomic Energy-Poland; AECL-Canada; Hungarian Academy of Sciences KFKI Atomic Energy Research Inst.; Japan Atomic Energy Agency; Nuclear Power Inst. of China; Kyoto Univ. Research Reactor Inst.

2010-03-01

369

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

370

Atmospheric pressure fluctuations and oxygen enrichment in waste tanks  

SciTech Connect

During In-Tank Precipitation (ITP) processing radiolytic decomposition of tetraphenylborate and water can produce benzene and hydrogen, which, given sufficiently high oxygen concentrations, can deflagrate. To prevent accumulations of benzene and hydrogen and avoid deflagration, continuous nitrogen purging is maintained. If the nitrogen purging is interrupted by, for example, a power failure, outside air will begin to seep into the tank through vent holes and cracks. Eventually a flammable mixture of benzene, hydrogen, and oxygen will occur (deflagration). However, this process is slow under steady-state conditions (constant pressure) and mechanisms to increase the exchange rate with the outside atmosphere must be considered. The most important mechanism of this kind is from atmospheric pressure fluctuations in which an increase in atmospheric pressure forces air into the tank which then mixes with the hydrogen-benzene mixture. The subsequent decrease in atmospheric pressure causes venting from the tank of the mixture -- the net effect being an increase in the tank`s oxygen concentration. Thus, enrichment occurs when the atmospheric pressure increases but not when the pressure decreases. Moreover, this natural atmospheric {open_quotes}pumping{close_quotes} is only important if the pressure fluctuations take place on a time scale longer than the characteristic mixing time scale (CMT) of the tank. If pressure fluctuations have a significantly higher frequency than the CMT, outside air will be forced into the tank and then out again before any significant mixing can occur. The CMT is not known for certain, but is estimated to be between 8 and 24 hours. The purpose of this report is to analyze yearly pressure fluctuations for a five year period to determine their statistical properties over 8 and 24-hour periods. The analysis also includes a special breakdown into summer and winter seasons and an analysis of 15-minute data from the SRTC Climatology Site.

Kurzeja, R.J.; Weber, A.H.

1993-07-01

371

Enrichment and Training Improve Cognition in Rats with Cortical Malformations  

PubMed Central

Children with malformations of cortical development (MCD) frequently have associated cognitive impairments which reduce quality of life. We hypothesized that cognitive deficits associated with MCD can be improved with environmental manipulation or additional training. The E17 methylazoxymethanol acetate (MAM) exposure model bears many anatomical hallmarks seen in human MCDs as well as similar behavioral and cognitive deficits. We divided control and MAM exposed Sprague-Dawley rats into enriched and non-enriched groups and tested performance in the Morris water maze. Another group similarly divided underwent sociability testing and also underwent Magnetic Resonance Imaging (MRI) scans pre and post enrichment. A third group of control and MAM rats without enrichment were trained until they reached criterion on the place avoidance task. MAM rats had impaired performance on spatial tasks and enrichment improved performance of both control and MAM animals. Although MAM rats did not have a deficit in sociability they showed similar improvement with enrichment as controls. MRI revealed a whole brain volume decrease with MAM exposure, and an increase in both MAM and control enriched volumes in comparison to non-enriched animals. In the place avoidance task, MAM rats required approximately 3 times as long to reach criterion as control animals, but with additional training were able to reach control performance. Environmental manipulation and additional training can improve cognition in a rodent MCD model. We therefore suggest that patients with MCD may benefit from appropriate alterations in educational strategies, social interaction and environment. These factors should be considered in therapeutic strategies. PMID:24358362

Jenks, Kyle R.; Lucas, Marcella M.; Duffy, Ben A.; Robbins, Ashlee A.; Gimi, Barjor; Barry, Jeremy M.; Scott, Rod C.

2013-01-01

372

An oxygen enrichment device for lowlanders ascending to high altitude  

PubMed Central

Background When ascending to the high altitude, people living in low altitude areas will suffer from acute mountain sickness. The aim of this study is to test the hypothesis that whether an oxygen concentration membrane can be made and used to construct a new portable oxygen enrichment device for individuals in acute exposure to the high altitude. Methods The membrane was fabricated using vinylsiloxane rubber, polyphenylene oxide hydrogen silicone polymers, chloroplatinic acid and isopropyl alcohol. The membrane was assembled in a frame and the performance was tested in terms of concentration of oxygen, flow rate of oxygen enriched air, pressure ratio across the membrane and ambient temperature. Furthermore, the oxygen concentration device was constructed using the membrane, a DC fan, vacuum pump and gas buffer. A nonrandomized preliminary field test was conducted, in which eight healthy male subjects were flown to Tibet (Lhasa, 3,700 m). First, subjects wore the oxygen enrichment device and performed an incremental exercise on cycle ergometer. The test included heart rate (HR), saturation of peripheral oxygen (SpO2) and physical work capacity (PWC). Then, after a rest period of 4 hours, the experimental protocol was repeated without oxygen enrichment device. Results The testing showed that the membrane could increase the oxygen concentration by up to 30%. Simulation test indicated that although the performance of the oxygen enrichment device decreased with altitudes, the oxygen concentration could still maintain 28% with flow rate of enriched air 110 cm3/s at 5000 m. The field test showed that higher SpO2, lower HR, and better PWC (measured by the PWC-170) were observed from all the subjects using oxygen enrichment device compared with non-using (P?enrichment device would be effective in improving exercise performance when ascending to the high altitude. PMID:24103365

2013-01-01

373

An oxygen enrichment attachment for use with humidified air  

PubMed Central

Jebson, P., Dewar, J., and White, J. (1974).Thorax, 29, 371-376. An oxygen enrichment attachment for use with humidified air. An oxygen enrichment attachment is described which fulfils the basic requirements for intubated patients. Using values for tidal volume and inspiratory time found in the type of patients for whom the attachment is intended, a range of mean inspired oxygen concentration has been given for 2, 4, 6, 8, and 10 1/min oxygen flow. Images PMID:4850557

Jebson, P.; Dewar, J.; White, J.

1974-01-01

374

Enrichment of fungi and degradation of styrene in biofilters  

Microsoft Academic Search

Summary Experiments were set up in order to enrich styrene-degrading fungi in biofilters under conditions representative for industrial off-gas treatment. From the support materials tested, polyurethane and perlite proved to be most suitable for enrichment of styrene-degrading fungi. The biofilter with perlite completely degraded styrene when amounts ranging between 290 and 675 mg\\/m in the influent gas were present. An

Huub H. J. Cox; José H. M. Houtman; Hans J. Doddema; Wim Harder

1993-01-01

375

Burnup studies of spent fuels of varying types and enrichment  

Microsoft Academic Search

This paper describes the results of fuel burnup measurements, made over a period of several years on discharged fuel from nuclear power plant and research reactor. The measured and calculated burnup of different spent fuel types, viz.: Natural uranium CANDU fuel bundles; 10.5% enriched booster rods; 20% enriched MTR fuel elements have been presented. High-resolution gamma spectrometry, using 137Cs and

S. A. Ansari; M. Asif; T. Rashid; K. G. Qasim

2007-01-01

376

Long-term nutrient enrichment decouples predator and prey production  

PubMed Central

Increased nutrient mobilization by human activities represents one of the greatest threats to global ecosystems, but its effects on ecosystem productivity can differ depending on food web structure. When this structure facilitates efficient energy transfers to higher trophic levels, evidence from previous large-scale enrichments suggests that nutrients can stimulate the production of multiple trophic levels. Here we report results from a 5-year continuous nutrient enrichment of a forested stream that increased primary consumer production, but not predator production. Because of strong positive correlations between predator and prey production (evidence of highly efficient trophic transfers) under reference conditions, we originally predicted that nutrient enrichment would stimulate energy flow to higher trophic levels. However, enrichment decoupled this strong positive correlation and produced a nonlinear relationship between predator and prey production. By increasing the dominance of large-bodied predator-resistant prey, nutrient enrichment truncated energy flow to predators and reduced food web efficiency. This unexpected decline in food web efficiency indicates that nutrient enrichment, a ubiquitous threat to aquatic ecosystems, may have unforeseen and unpredictable effects on ecosystem structure and productivity. PMID:20018677

Davis, John M.; Rosemond, Amy D.; Eggert, Susan L.; Cross, Wyatt F.; Wallace, J. Bruce

2009-01-01

377

Preparation of a monolith functionalized with zinc oxide nanoparticles and its application in the enrichment of fluoroquinolone antibiotics.  

PubMed

This study describes the enrichment ability of ZnO-modified methacrylic acid-co-ethylene dimethacrylate polymer monoliths as stationary phases for the simultaneous determination of antibiotics (ofloxacin, ciprofloxacin, enoxacin, and pefloxacin) combined with high-performance liquid chromatography. The prepared monolith was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier-transformed infrared spectroscopy, and thermogravimetric analysis. The polymer monolith microextraction method has been applied to the enrichment of fluoroquinolone antibiotics and satisfactory results were obtained in the analysis of water samples. Compared with the conventional methacrylic acid based monolith, the developed monolith exhibited a higher enrichment capacity because of the introduction of zinc oxide into the preparation process. PMID:25354394

Liu, Dan; Ma, Jiutong; Jin, Yan; Li, Xiqian; Zhou, Xiao; Jia, Qiong; Zhou, Weihong

2015-01-01

378

Large-scale carbon isotope fractionation in evaporites and the generation of extremely 13C-enriched methane  

NASA Astrophysics Data System (ADS)

Petrographic, fluid-inclusion, geochemical, and gas stable isotope data are reported here for a Permian Zechstein evaporite sequence. This deposit is a geochemically unaltered sequence. Bromine concentrations show a continuous evaporation profile with little postdepositional alteration in halite chemistry. Bacterial fermentation gases, identified in primary inclusions, change from an N2-H2S composition in the lower-middle halite series to a CH4-H2 composition in the upper halite and potash series. Carbon isotope results for CH4 show a 13C enrichment up-sequence from typical biogenic values of -45‰ to -50‰ to extremely unusual 13C-enriched values as high as +21‰. The ?D values for these 13C-enriched CH4 gases range from -240‰ to -377‰. A model is proposed for the formation of the CH4 gases whereby the dominant isotopic fractionation process controlling the system was evaporation of the brines. This generated a progressive 13C enrichment in the carbon in the residual brines due to preferential loss of 12CO2 to the atmosphere. The resulting CH4 generated in the sediments, as evaporation and precipitation advanced, recorded this 13C enrichment in the carbon reservoir. Therefore, the isotopic profile observed in this sequence today represents a primary feature with little evidence for postdepositional migration.

Potter, Joanna; Siemann, Michael G.; Tsypukov, Mikhail

2004-06-01

379

Examination of the conversion of the U.S. submarine fleet from highly enriched uranium to low enriched uranium  

E-print Network

The nuclear reactors used by the U.S. Navy for submarine propulsion are currently fueled by highly enriched uranium (HEU), but HEU brings administrative and political challenges. This issue has been studied by the Navy ...

McCord, Cameron (Cameron Liam)

2014-01-01

380

Seasonality of Leaf Carbon Isotopic Composition and Leaf Water Isotopic Enrichment in a Mixed Evergreen Forest in Southern California  

NASA Astrophysics Data System (ADS)

Leaf carbon isotopic composition and leaf water isotopic enrichment reflect physiological processes and are important for linking local and regional scale processes to global patterns. We investigated how seasonality affects the isotopic composition of bulk leaf carbon, leaf sugar carbon, and leaf water hydrogen under a Mediterranean climate. Leaf and stem samples were collected monthly from four tree species (Calocedrus decurrens, Pinus lambertiana, Pinus ponderosa, and Quercus chrysolepis) at the James San Jacinto Mountain Reserve in southern California. Mean monthly bulk leaf carbon isotopic composition varied from -34.5 % in P. ponderosa to -24.7 % in P. lambertiana and became more depleted in 13C from the spring to the summer. Mean monthly leaf sugar varied from -29.3 % in P. ponderosa to -21.8 % in P. lambertiana and was enriched in 13C during the winter, spring and autumn, but depleted during the mid-summer. Leaf water hydrogen isotopic composition was 28.4 to 68.8 % more enriched in deuterium than source water and this enrichment was greater as seasonal drought progressed. These data indicate that leaf carbon and leaf water hydrogen isotopic composition provide sensitive measures that connect plant physiological processes to short-term climatic variability.

Santiago, L. S.; Sickman, J. O.; Goulden, M.; DeVan, C.; Pasquini, S. C.; Pivovaroff, A. L.

2011-12-01

381

Processing of LEU targets for Mo production -- Demonstration of a modified Cintichem process  

Microsoft Academic Search

Two demonstrations of the use of the Cintichem process on simulated low enriched uranium (LEU, < 20% ²³U) targets were run by personnel in the BATAN Isotope Production Facilities at PUSPIPTEK (Serpong, Indonesia). These demonstrations were done using a solution of either natural or depleted uranium spiked with irradiated high enriched uranium (HEU). The activity levels were low enough to

Z. Aliludin; A. Mutalib; A. Sukmana; Kadarisman; A. H. Gunawan; G. F. Vandegrift; D. Wu; B. Srinivasan; J. L. Snelgrove

1995-01-01

382

10 CFR 74.33 - Nuclear material control and accounting for uranium enrichment facilities authorized to produce...  

Code of Federal Regulations, 2012 CFR

...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...possess equipment capable of enriching uranium or operate an enrichment...

2012-01-01

383

10 CFR 74.33 - Nuclear material control and accounting for uranium enrichment facilities authorized to produce...  

Code of Federal Regulations, 2011 CFR

...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...possess equipment capable of enriching uranium or operate an enrichment...

2011-01-01

384

10 CFR 74.33 - Nuclear material control and accounting for uranium enrichment facilities authorized to produce...  

...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...possess equipment capable of enriching uranium or operate an enrichment...

2014-01-01

385

10 CFR 74.33 - Nuclear material control and accounting for uranium enrichment facilities authorized to produce...  

Code of Federal Regulations, 2013 CFR

...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...possess equipment capable of enriching uranium or operate an enrichment...

2013-01-01

386

10 CFR 74.33 - Nuclear material control and accounting for uranium enrichment facilities authorized to produce...  

Code of Federal Regulations, 2010 CFR

...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...Nuclear material control and accounting for uranium enrichment facilities authorized to produce...possess equipment capable of enriching uranium or operate an enrichment...

2010-01-01

387

Surface reactions of iron - enriched smectites: adsorption and transformation of hydroxy fatty acids and phenolic acids  

NASA Astrophysics Data System (ADS)

Iron-enriched smectites play an important role in adsorption and transformation of soil organic components. Soil organo-clay complexes, and in particular humin contain hydroxy fatty acids, which are derived from plant biopolymer cutin. Phenolic acids belong to another major group of organic acids detected in soil. They participate in various soil processes, and are of concern due to their allelopathic activity. We studied the reactivity of iron-enriched smectites (Fe(III)-montmorillonite and nontronite) toward both groups of acids. We used fatty acids- 9(10),16-dihydroxypalmitic acid (diHPA), isolated from curtin, and 9,10,16-trihydroxypalmitic acid (triHPA); the following phenolic acids were used: ferulic, p-coumaric, syringic, and vanillic. Adsorption of both groups of acids was measured. The FTIR spectra of fatty acid-mineral complexes indicated inner-sphere complexation of fatty acids with iron-enriched smectites (versus outer-sphere complexation with Ca(II)-montmorillonite). The LC-MS results demonstrated enhanced esterification of fatty acids on the iron-enriched smectite surfaces (as compared to Ca(II)-montmorillonite). This study suggests that fatty acids can be esterified on the iron-enriched smectite surfaces, which results in the formation of stable organo-mineral complexes. These complexes may serve as a model for the study of natural soil organo-clay complexes and humin. The reaction of phenolic acids with Fe(III)-montmorillonite demonstrated their oxidative transformation by the mineral surfaces, which was affected by molecular structure of acids. The following order of their transformation was obtained: ferulic >syringic >p-coumaric >vanillic. The LC-MS analysis demonstrated the presence of dimers, trimers, and tetramers of ferulic acid on the surface of Fe(III)-montmorillonite. Oxidation and transformation of ferulic acid were more intense on the surface of Fe(III)-montmorillonite as compared to Fe(III) in solution due to stronger complexation on the Fe(III)-motnomrillonite surface. Our study demonstrate the importance of iron-enriched minerals for the abiotic formation of humic materials and for the transformation of aromatic (phenolic) pollutants.

Polubesova, Tamara; Olshansky, Yaniv; Eldad, Shay; Chefetz, Benny

2014-05-01

388

LDL and HDL enriched in triglyceride promote abnormal cholesterol transport.  

PubMed

Hypertriglyceridemia induces multiple changes in lipoprotein composition. Here we investigate how one of these modifications, triglyceride (TG) enrichment, affects HDL and LDL function when this alteration occurs under conditions in which more polar components can naturally re-equilibrate. TG-enriched lipoproteins were produced by co-incubating VLDL, LDL, and HDL with cholesteryl ester (CE) transfer protein. The resulting 2.5-fold increase in TG/CE ratio did not measurably alter the apoprotein composition of LDL or HDL, or modify LDL size. HDL mean diameter increased slightly from 9.1 to 9.4 nm. Modified LDL was internalized by fibroblasts normally, but its protein was degraded much less efficiently. This likely reflects an aberrant apolipoprotein B (apoB) conformation, as suggested by its resistance to V8 protease digestion and altered LDL electrophoretic mobility. TG-enriched LDL ineffectively down-regulated cholesterol biosynthesis compared with control LDL at the same protein concentration, but was equivalent in sterol regulation when compared on a cholesterol basis. TG-enriched HDL promoted greater net cholesterol efflux from cholesterol-loaded J774 cells. However, cholesterol associated with TG-enriched HDL was inefficiently esterified by lecithin:cholesterol acyltransferase, and TG-enriched HDLs were poor donors of CE to HepG2 hepatocytes by selective uptake. We conclude that TG-enrichment, in the absence of other significant alterations in lipoprotein composition, is sufficient to alter both cholesterol delivery and removal mechanisms. Some of these abnormalities may contribute to increased coronary disease in hypertriglyceridemia. PMID:12177170

Skeggs, Josephine W; Morton, Richard E

2002-08-01

389

Generalized Modeling of Enrichment Cascades That Include Minor Isotopes  

SciTech Connect

The monitoring of enrichment operations may require innovative analysis to allow for imperfect or missing data. The presence of minor isotopes may help or hurt - they can complicate a calculation or provide additional data to corroborate a calculation. However, they must be considered in a rigorous analysis, especially in cases involving reuse. This study considers matched-abundanceratio cascades that involve at least three isotopes and allows generalized input that does not require all feed assays or the enrichment factor to be specified. Calculations are based on the equations developed for the MSTAR code but are generalized to allow input of various combinations of assays, flows, and other cascade properties. Traditional cascade models have required specification of the enrichment factor, all feed assays, and the product and waste assays of the primary enriched component. The calculation would then produce the numbers of stages in the enriching and stripping sections and the remaining assays in waste and product streams. In cases where the enrichment factor or feed assays were not known, analysis was difficult or impossible. However, if other quantities are known (e.g., additional assays in waste or product streams), a reliable calculation is still possible with the new code, but such nonstandard input may introduce additional numerical difficulties into the calculation. Thus, the minimum input requirements for a stable solution are discussed, and a sample problem with a non-unique solution is described. Both heuristic and mathematically required guidelines are given to assist the application of cascade modeling to situations involving such non-standard input. As a result, this work provides both a calculational tool and specific guidance for evaluation of enrichment cascades in which traditional input data are either flawed or unknown. It is useful for cases involving minor isotopes, especially if the minor isotope assays are desired (or required) to be important contributors to the overall analysis.

Weber, Charles F [ORNL

2012-01-01

390

Erythrocyte Enrichment in Hematopoietic Progenitor Cell Cultures Based on Magnetic Susceptibility of the Hemoglobin  

PubMed Central

Using novel media formulations, it has been demonstrated that human placenta and umbilical cord blood-derived CD34+ cells can be expanded and differentiated into erythroid cells with high efficiency. However, obtaining mature and functional erythrocytes from the immature cell cultures with high purity and in an efficient manner remains a significant challenge. A distinguishing feature of a reticulocyte and maturing erythrocyte is the increasing concentration of hemoglobin and decreasing cell volume that results in increased cell magnetophoretic mobility (MM) when exposed to high magnetic fields and gradients, under anoxic conditions. Taking advantage of these initial observations, we studied a noninvasive (label-free) magnetic separation and analysis process to enrich and identify cultured functional erythrocytes. In addition to the magnetic cell separation and cell motion analysis in the magnetic field, the cell cultures were characterized for cell sedimentation rate, cell volume distributions using differential interference microscopy, immunophenotyping (glycophorin A), hemoglobin concentration and shear-induced deformability (elongation index, EI, by ektacytometry) to test for mature erythrocyte attributes. A commercial, packed column high-gradient magnetic separator (HGMS) was used for magnetic separation. The magnetically enriched fraction comprised 80% of the maturing cells (predominantly reticulocytes) that showed near 70% overlap of EI with the reference cord blood-derived RBC and over 50% overlap with the adult donor RBCs. The results demonstrate feasibility of label-free magnetic enrichment of erythrocyte fraction of CD34+ progenitor-derived cultures based on the presence of paramagnetic hemoglobin in the maturing erythrocytes. PMID:22952572

Jin, Xiaoxia; Abbot, Stewart; Zhang, Xiaokui; Kang, Lin; Voskinarian-Berse, Vanessa; Zhao, Rui; Kameneva, Marina V.; Moore, Lee R.; Chalmers, Jeffrey J.; Zborowski, Maciej

2012-01-01

391

Enrichment of calcifying extracellular vesicles using density-based ultracentrifugation protocol  

PubMed Central

Calcifying extracellular vesicles (EVs) released from cells within atherosclerotic plaques have received increased attention for their role in mediating vascular calcification, a major predictor of cardiovascular morbidity and mortality. However, little is known about the difference between this pathologic vesicle population and other EVs that contribute to physiological cellular processes. One major challenge that hinders research into these differences is the inability to selectively isolate calcifying EVs from other vesicle populations. In this study, we hypothesized that the formation of mineral within calcifying EVs would increase the density of the vesicles such that they would pellet at a faster rate during ultracentrifugation. We show that after 10 min of ultracentrifugation at 100,000×g, calcifying EVs are depleted from the conditioned media of calcifying coronary artery smooth muscle cells and are enriched in the pelleted portion. We utilized mass spectrometry to establish functional proteomic differences between the calcifying EVs enriched in the 10 min ultracentrifugation compared to other vesicle populations preferentially pelleted by longer ultracentrifugation times. The procedures established in this study will allow us to enrich the vesicle population of interest and perform advanced proteomic analyses to find subtle differences between calcifying EVs and other vesicle populations that may be translated into therapeutic targets for vascular calcification. Finally, we will show that the differences in ultracentrifugation times required to pellet the vesicle populations can also be used to estimate physical differences between the vesicles. PMID:25491249

Hutcheson, Joshua D.; Goettsch, Claudia; Pham, Tan; Iwashita, Masaya; Aikawa, Masanori; Singh, Sasha A.; Aikawa, Elena

2014-01-01

392

A novel titanium dioxide-polydimethylsiloxane plate for phosphopeptide enrichment and mass spectrometry analysis.  

PubMed

The phosphorylation of proteins is a major post-translational modification that is required for the regulation of many cellular processes and activities. Mass spectrometry signals of low-abundance phosphorylated peptides are commonly suppressed by the presence of abundant non-phosphorylated peptides. Therefore, one of the major challenges in the detection of low-abundance phosphopeptides is their enrichment from complex peptide mixtures. Titanium dioxide (TiO2) has been proven to be a highly efficient approach for phosphopeptide enrichment and is widely applied. In this study, a novel TiO2 plate was developed by coating TiO2 particles onto polydimethylsiloxane (PDMS)-coated MALDI plates, glass, or plastic substrates. The TiO2-PDMS plate (TP plate) could be used for on-target MALDI-TOF analysis, or as a purification plate on which phosphopeptides were eluted out and subjected to MALDI-TOF or nanoLC-MS/MS analysis. The detection limit of the TP plate was ?10-folds lower than that of a TiO2-packed tip approach. The capacity of the ?2.5 mm diameter TiO2 spots was estimated to be ?10 ?g of ?-casein. Following TiO2 plate enrichment of SCC4 cell lysate digests and nanoLC-MS/MS analysis, ?82% of the detected proteins were phosphorylated, illustrating the sensitivity and effectiveness of the TP plate for phosphoproteomic study. PMID:24491770

Chen, Chao-Jung; Lai, Chien-Chen; Tseng, Mei-Chun; Liu, Yu-Ching; Liu, Yu-Huei; Chiou, Liang-Wei; Tsai, Fuu-Jen

2014-02-17

393

Amazon capims (floating grassmats): A source of sup 13 C enriched methane to the troposphere  

SciTech Connect

The {sup 13}C isotope composition of methane emitted to the troposphere from Amazon capims (floating grassmats) ranged from {minus}36.9 to {minus}48.0{per thousand} averaging {minus}44.4 {plus minus} 4.2{per thousand}. All pools of methane associated with the grassmats were {sup 13}C enriched; methane withdrawn from plant stems ranged from {minus}39 to {minus}49{per thousand} while bubbles stirred from the root mat averaged {minus}41.4{per thousand}. As the CH{sub 4} flux from these habitats makes up some 40% of the total flux from the Amazon flooplain, CH{sub 4} emissions form the region as a whole must be enriched in the heavy carbon isotope. Methane withdrawn from the stems of five genera of rooted macrophysics ranging in latitude from the Florida Everglades to the Alaskan Arctic exhibited {sup 13}C enrichment relative to the sedimentary methane bubble reservoir. Several hypotheses based upon isotopic fractionation by methane transport, oxidation and production processes are proposed to explain this phenomenon.

Chanton, J. (Florida State Univ., Tallahassee (USA)); Crill, P. (Univ. of New Hampshire, Durham (USA)); Martens, C. (Univ. of North Carolina, Chapel Hill (USA)); Bartlett, K.

1989-08-01

394

Acoustical enrichment during early postnatal development changes response properties of inferior colliculus neurons in rats.  

PubMed

The structure and function of the auditory system may be influenced by acoustic stimulation, especially during the early postnatal period. This study explores the effects of an acoustically enriched environment applied during the third and fourth week of life on the responsiveness of inferior colliculus neurons in rats. The enrichment comprised a spectrally and temporally modulated complex sound reinforced with several target acoustic stimuli, one of which triggered a reward release. The exposure permanently influenced neuronal representation of the sound frequency and intensity, resulting in lower excitatory thresholds at neuronal characteristic frequency, an increased frequency selectivity, larger response magnitudes, steeper rate-intensity functions and an increased spontaneous activity. The effect was general and non-specific, spanning the entire hearing range - no changes specific to the frequency band of the target stimuli were found. The alterations depended on the activity of animals during the enrichment - a higher activity of rats in the stimulus-reward paradigm led to more profound changes compared with the treatment when the stimulus-reward paradigm was not used. Furthermore, the exposure in early life led to permanent changes in response parameters, whereas the application of the same environment in adulthood influenced only a subset of the examined parameters and had only a temporary effect. These findings indicate that a rich and stimulating acoustic environment during early development, particularly when reinforced by positive feedback, may permanently affect signal processing in the subcortical auditory nuclei, including the excitatory thresholds of neurons and their frequency and intensity resolution. PMID:25224160

Bureš, Zbyn?k; Bartošová, Jolana; Lindovský, Ji?í; Chumak, Tetyana; Popelá?, Ji?í; Syka, Josef

2014-12-01

395

Safety Evaluation Report for the Claiborne Enrichment Center, Homer, Louisiana (Docket No. 70-3070)  

SciTech Connect

This report documents the US Nuclear Regulatory Commission (NRC) staff review and safety evaluation of the Louisiana Energy Services, L.P. (LES, the applicant) application for a license to possess and use byproduct, source, and special nuclear material and to enrich natural uranium to a maximum of 5 percent U-235 by the gas centrifuge process. The plant, to be known as the Claiborne Enrichment Center (CEC), would be constructed near the town of Homer in Claiborne Parish, Louisiana. At full production in a given year, the plant will receive approximately 4,700 tonnes of feed UF{sub 6} and produce 870 tonnes of low-enriched UF{sub 6}, and 3,830 tonnes of depleted UF{sub 6} tails. Facility construction, operation, and decommissioning are expected to last 5, 30, and 7 years, respectively. The objective of the review is to evaluate the potential adverse impacts of operation of the facility on worker and public health and safety under both normal operating and accident conditions. The review also considers the management organization, administrative programs, and financial qualifications provided to assure safe design and operation of the facility. The NRC staff concludes that the applicant`s descriptions, specifications, and analyses provide an adequate basis for safety review of facility operations and that construction and operation of the facility does not pose an undue risk to public health and safety.

Not Available

1994-01-01

396

Multilayer interparticle linking hybrid MOF-199 for noninvasive enrichment and analysis of plant hormone ethylene.  

PubMed

Ethylene, an important plant hormone, is of utmost importance during many developmental processes of plants. However, the efficient enrichment and analysis of trace ethylene still remains a challenge. A simple and mild multilayer interparticle linking strategy was proposed to fabricate a novel hybrid MOF-199 enrichment coating. Strong chemical interparticle linkages throughout the coating improved the durability and reproducibility of hybrid MOF-199 coating dramatically. This coating performed a significant extraction superiority of ethylene over commonly used commercial coatings, attributed to the multiple interactions including "molecular sieving effect", hydrogen bonding, open metal site interaction, and ?-? affinity. The hybridization of multiwalled carbon nanotubes (MWCNTs) with MOF-199 further improved the enrichment capability and also acted as a hydrophobic "shield" to prevent the open metal sites of MOF-199 from being occupied by water molecules, which effectively improved the moisture-resistant property of MOF-199/CNTs coating. Finally, this novel enrichment method was successfully applied for the noninvasive analysis of trace ethylene, methanol, and ethanol from fruit samples with relatively high humidity. The low detection limit was 0.016 ?g/L for ethylene. It was satisfactory that trace ethylene could be actually detected from fruit samples by this noninvasive method. Good recoveries of spiked grape, wampee, blueberry, and durian husk samples were obtained in the range of 90.0-114%, 79.4-88.6%, 78.5-86.8%, and 85.2-105% with the corresponding relative standard deviations of 4.8-9.8%, 6.9-8.9%, 3.8-8.1%, and 9.3-10.5% (n = 3), respectively. PMID:24576104

Zhang, Zhuomin; Huang, Yichun; Ding, Weiwei; Li, Gongke

2014-04-01

397

Effect of cocoa-enriched diets on lymphocytes involved in adjuvant arthritis in rats.  

PubMed

Cocoa and its flavonoids have potential anti-inflammatory properties in vitro and in acute inflammation models in vivo. The aim of the present study was to ascertain the effects of two cocoa-enriched diets on adjuvant arthritis (AA) in rats, considering not only clinical and biochemical inflammatory indices, but also antibody response and lymphocyte composition. Female Wistar rats were fed with a 5 or 10 % cocoa-enriched diet beginning 2 weeks before arthritis induction and until the end of the study. AA was induced by an intradermal injection of heat-killed Mycobacterium butyricum suspension. The hind-paw swelling (plethysmometry), serum anti-mycobacterial antibody concentration (ELISA), blood and inguinal lymph node lymphocyte subset percentage (flow cytometry), and IL-2, interferon ? and PGE? released from splenocytes (ELISA) were assessed. Although the cocoa diets had no significant effect on hind-paw swelling, a tendency to reduce it was observed at the end of the study. Cocoa-enriched diets were able to decrease the serum anti-mycobacterial antibody concentration and the splenocyte PGE2 production, as well as the proportion of T-helper (Th) lymphocytes in blood and regional lymph nodes, which probably includes cells responsible for the arthritic process. The cocoa diets prevented a decrease in the proportion of regulatory T-cells in blood and a disequilibrium between inguinal lymph node natural killer (NK) CD8? and NK CD8? subsets. In conclusion, the cocoa-enriched diets during AA were not able to significantly decrease joint inflammation but modified Th-cell proportions and prevented specific antibody synthesis. PMID:21762542

Ramos-Romero, Sara; Pérez-Cano, Francisco J; Castellote, Cristina; Castell, Margarida; Franch, Àngels

2012-02-01

398

Enriched Iron(III)-Reducing Bacterial Communities are Shaped by Carbon Substrate and Iron Oxide Mineralogy  

PubMed Central

Iron (Fe) oxides exist in a spectrum of structures in the environment, with ferrihydrite widely considered the most bioavailable phase. Yet, ferrihydrite is unstable and rapidly transforms to more crystalline Fe(III) oxides (e.g., goethite, hematite), which are poorly reduced by model dissimilatory Fe(III)-reducing microorganisms. This begs the question, what processes and microbial groups are responsible for reduction of crystalline Fe(III) oxides within sedimentary environments? Further, how do changes in Fe mineralogy shape oxide-hosted microbial populations? To address these questions, we conducted a large-scale cultivation effort using various Fe(III) oxides (ferrihydrite, goethite, hematite) and carbon substrates (glucose, lactate, acetate) along a dilution gradient to enrich for microbial populations capable of reducing Fe oxides spanning a wide range of crystallinities and reduction potentials. While carbon source was the most important variable shaping community composition within Fe(III)-reducing enrichments, both Fe oxide type and sediment dilution also had a substantial influence. For instance, with acetate as the carbon source, only ferrihydrite enrichments displayed a significant amount of Fe(III) reduction and the well-known dissimilatory metal reducer Geobacter sp. was the dominant organism enriched. In contrast, when glucose and lactate were provided, all three Fe oxides were reduced and reduction coincided with the presence of fermentative (e.g., Enterobacter spp.) and sulfate-reducing bacteria (e.g., Desulfovibrio spp.). Thus, changes in Fe oxide structure and resource availability may shift Fe(III)-reducing communities between dominantly metal-respiring to fermenting and/or sulfate-reducing organisms which are capable of reducing more recalcitrant Fe phases. These findings highlight the need for further targeted investigations into the composition and activity of speciation-directed metal-reducing populations within natural environments. PMID:23316187

Lentini, Christopher J.; Wankel, Scott D.; Hansel, Colleen M.

2012-01-01

399

Pyroxenite is a possible cause of enriched magmas in island arc settings: Gorely volcano (Kamchatka)  

NASA Astrophysics Data System (ADS)

Kamchatka peninsula (Russia) is an island-arc with a complex geological history and structure. It has three distinct volcanic fronts, whose origins are still debated. Moreover, a junction with the Aleutian Arc (at ~56oN) complicates the understanding of geodynamics at the region. The process of magma generation in Kamchatka involves several components: N-MORB mantle wedge (variably depleted), slab fluids and melts, and enriched mantle [Churikova et al. 2001, 2007; Yogodzinsky et al. 2001; Volynets et al. 2010]. Two of these end members (mantle wedge, slab fluids) are well studied [Portnyagin et al. 2007; Duggen et al. 2007]. However, the nature/genesis of the enriched magmas is unclear. In the standard model of arc volcanism depleted mantle peridotite in the mantle wedge partially melts to form parental basalts. However, evidence for pyroxenite melting in the arc environment was reported for the Mexican Volcanic Belt [Straub et al, 2008; Straub et al, 2013] and for Kamchatka [Portnyagin, 2009; Portnyagin, 2011; Bryant et al., 2011; Gavrilenko, 2012]. High precision Ni, Ca, and Mn contents of olivines from Gorely volcano confirm the existence of pyroxenite source in the mantle wedge [Gavrilenko, 2013]. Our forward modeling using Arc Basalt Simulator 4.0 (ABS) by [Kimura et al. 2011]) shows that we have primitive mantle as a source for Gorely volcano, a mantle more enriched than the DMM in the standard model for arc magmatism) REE inverse modeling [after Feigenson et al, 1983] agrees with the ABS forward model, returning the same REE pattern for the source. In contrast, ABS modeling for Mutnovsky volcano (next to Gorely, but closer to the trench) shows standard DMM as the source for the volcano. We conclude that DMM is the composition for the mantle wedge rocks beneath Gorely volcano, but the enrichment of the parental melts at Gorely volcano is caused by reaction of DMM peridotite with slab melts/fluids to produce pyroxenite.

Gavrilenko, M.; Carr, M. J.; Herzberg, C. T.; Ozerov, A.

2013-12-01

400

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

PubMed

Complex gradients in forest structure across the landscape of offshore mangrove islands in Belize are associated with nutrient deficiency and flooding. While nutrient availability can affect many ecological processes, here we investigate how N and P enrichment interact with forest structure in three distinct zones (fringe, transition, dwarf) to alter patterns of herbivory as a function of folivory, loss of yield, and tissue mining. The effects of nutrient addition and zone varied by functional feeding group or specific herbivore. Folivory ranged from 0 to 0.4% leaf area damaged per month, but rates did not vary by either nutrient enrichment or zone. Leaf lifetime damage ranged from 3 to 10% of the total leaf area and was caused primarily by the omnivorous tree crab Aratus pisonii. We detected two distinct spatial scales of response by A. pisonii that were unrelated to nutrient treatment, i.e., most feeding damage occurred in the fringe zone and crabs fed primarily on the oldest leaves in the canopy. Loss of yield caused by the bud moth Ecdytolopha sp. varied by zone but not by nutrient treatment. A periderm-mining Marmara sp. responded positively to nutrient enrichment and closely mirrored the growth response by Rhizophora mangle across the tree height gradient. In contrast, a leaf-mining Marmara sp. was controlled by parasitoids and predators that killed >89% of its larvae. Thus, nutrient availability altered patterns of herbivory of some but not all mangrove herbivores. These findings support the hypothesis that landscape heterogeneity of the biotic and abiotic environment has species-specific effects on community structure and trophic interactions. Predicting how herbivores respond to nutrient over-enrichment in mangrove ecosystems also requires an assessment of habitat heterogeneity coupled with feeding strategies and species-specific behavior measured on multiple scales of response. PMID:17566784

Feller, Ilka C; Chamberlain, Anne

2007-09-01

401

[CD271 enrichment does not help isolating mesenchymal stromal cells from].  

PubMed

Reports on the isolation of mesencnymal stromal cells (MSCs) from granulocyte colony stimulating factor mobilized peripheral blood (G-CSF-mobilized PB) using regular culturing techniques are controversial. Enrichment techniques such as CD133 isolation have increased the success rates. CD271 is a well-known marker for enrichment of MSCs from bone marrow (BM). In the present study, we aimed to find out whether CD271 enrichment can help isolation of MSCs from G-CSF-mobilized PB. Five G-CSF-mobilized PB samples were collected from the remnant parts of the bags used for BM transplantation. Five BM samples were used as the control. Mononuclear cells (MNCs) from both resources were collected and underwent magnetic sorting for CD271-positive cells. The isolated cells were cultured, undergoing flowcytometry and differentiation assays to determine if they fulfill MSCs characteristics. CD271-positive portion of G-CSF-mobilized PB did not yield any cell outgrowth but the BM counterpart could successfully form MSC colonies. Although the percentage of CD271+ cells showed no difference between BM-MNCs and G-CSF-mobilized PB-MNCs, hematopoietic markers such as CD45, CD34 and CD133 composed a higher percentage of CD271-positive cells in the G-CSF-mobilized PB group. Results obtained indicated that CD271 enrichment does not help isolation of MSCs from G-CSF-mobilized PB. In this source, almost all of the CD271+ cells are from hematopoietic origin and the frequency of MSCs is so low that possibly during the process of cell isolation most of them are lost and the isolation fails. PMID:25509351

Ahrari, I; Attar, A; Zarandi, N M; Zakerinia, M; Maharlooei, M K; Monabati, A

2013-01-01

402

PERSPECTIVES ON INTRACLUSTER ENRICHMENT AND THE STELLAR INITIAL MASS FUNCTION IN ELLIPTICAL GALAXIES  

SciTech Connect

Stars formed in galaxy cluster potential wells must be responsible for the high level of enrichment measured in the intracluster medium (ICM); however, there is increasing tension between this truism and the parsimonious assumption that the stars in the generally old population studied optically in cluster galaxies emerged from the same formation sites at the same epochs. We construct a phenomenological cluster enrichment model to demonstrate that ICM elemental abundances are underestimated by a factor >2 for standard assumptions about the stellar population-a discrepancy we call the ''cluster elemental abundance paradox''. Recent evidence of an elliptical galaxy initial mass function (IMF) skewed to low masses deepens the paradox. We quantify the adjustments to the star formation efficiency and IMF, and Type Ia supernovae (SNIa) production efficiency, required to resolve this while being consistent with the observed ICM abundance pattern. The necessary enhancement in metal enrichment may, in principle, originate in the observed stellar population if a larger fraction of stars in the supernova-progenitor mass range form from an IMF that is either bottom-light or top-heavy, with the latter in some conflict with observed ICM abundance ratios. Other alternatives that imply more modest revisions to the IMF, mass return and remnant fractions, and primordial fraction, posit an increase in the fraction of 3-8 M{sub Sun} stars that explode as SNIa or assume that there are more stars than conventionally thought-although the latter implies a high star formation efficiency. We discuss the feasibility of these various solutions and the implications for the diversity of star formation in the universe, the process of elliptical galaxy formation, and the origin of this ''hidden'' source of ICM metal enrichment.

Loewenstein, Michael, E-mail: Michael.Loewenstein.1@nasa.gov [Also at CRESST and X-ray Astrophysics Laboratory, NASA/GSFC, Greenbelt, MD (United States)

2013-08-10

403

Formation of magnetite-enriched zones in and offshore of a mesotidal estuarine lagoon: An environmental magnetic study of Tauranga Harbour and Bay of Plenty, New Zealand  

NASA Astrophysics Data System (ADS)

Magnetic iron minerals are widespread and indicative sediment constituents in estuarine, coastal and shelf systems. We combine environmental magnetic, sedimentological and numerical methods to identify magnetite-enriched placer-like zones in a complex coastal system and delineate their formation mechanisms. Magnetic susceptibility and remanence measurements on 245 surficial sediment samples collected in and around Tauranga Harbour, the largest barrier-enclosed tidal estuary of New Zealand, reveal several discrete enrichment zones controlled by local hydrodynamic conditions. Active magnetite enrichment takes place in tidal channels, which feed into two coast-parallel nearshore magnetite-enriched belts centered at water depths of 6-10 m and 10-20 m. A close correlation between magnetite content and magnetic grain size was found, where higher susceptibility values are associated within coarser magnetic crystal sizes. Two key mechanisms for magnetite enrichment are identified. First, tide-induced residual currents primarily enable magnetite enrichment within the estuarine channel network. A coast-parallel, fine sand magnetite enrichment belt in water depths of less than 10 m along the barrier island has a strong decrease in magnetite content away from the southern tidal inlet and is apparently related to active coast-parallel transport combined with mobilizing surf zone processes. A second, less pronounced, but more uniform magnetite enrichment belt at 10-20 m water depth is composed of non-mobile, medium-coarse-grained relict sands, which have been reworked during post-glacial sea level transgression. We demonstrate the potential of magnetic methods to reveal and differentiate coastal magnetite enrichment patterns and investigate their formative mechanisms.

Badesab, Firoz; von Dobeneck, Tilo; Bryan, Karin R.; Müller, Hendrik; Briggs, Roger M.; Frederichs, Thomas; Kwoll, Eva

2012-06-01

404

Optogalvanic isotope enrichment of Cu ions in Cu-Ne positive column discharges  

E-print Network

Optogalvanic isotope enrichment of Cu ions in Cu-Ne positive column discharges M. J. Kushner The isotopic enrichment of copper ions in a positive column Cu-Ne discharge using optogalvanic excitation the 63-amu isotope of copper is enriched relative to the neutral abundance. Enrichment as large as 10

Kushner, Mark

405

Environmental enrichment restores neurogenesis and rapid acquisition in aged rats  

PubMed Central

Strategies combatting cognitive decline among the growing aging population are vital. We tested whether environmental enrichment could reverse age-impaired rapid spatial search strategy acquisition concomitantly with hippocampal neurogenesis in rats. Young (5–8 mo) and aged (20–22 mo) male Fischer 344 rats were pair-housed and exposed to environmental enrichment (n=7 young, 9 aged) or housed individually (n=7 young, 7 aged) for ten weeks. After five weeks, hidden platform trials (5 blocks of 3 trials; 15m IBI), a probe trial, and then visible platform trials (5 blocks of 3 trials; 15m IBI) commenced in the water maze. One week after testing, rats were given 5 daily bromodeoxyuridine (BrdU, 50mg/kg; i.p.) injections and perfused 4 weeks later to quantify neurogenesis. Although young rats outperformed aged rats, aged enriched rats outperformed aged individually-housed rats on all behavioral measures. Neurogenesis decreased with age but enrichment enhanced new cell survival, regardless of age. The novel correlation between new neuron number and behavioral measures obtained in a rapid water maze task among aged rats, suggests that environmental enrichment increases their ability to rapidly acquire and flexibly use spatial information along with neurogenesis. PMID:22795793

Speisman, Rachel. B.; Kumar, Ashok; Rani, Asha; Pastoriza, Jessica M.; Severance, Jamie E.; Foster, Thomas C.; Ormerod, Brandi K.

2012-01-01

406

Target enrichment using parallel nanoliter quantitative PCR amplification  

PubMed Central

Background Next generation targeted resequencing is replacing Sanger sequencing at high pace in routine genetic diagnosis. The need for well validated, high quality enrichment platforms to complement the bench-top next generation sequencing devices is high. Results We used the WaferGen Smartchip platform to perform highly parallelized PCR based target enrichment for a set of known cancer genes in a well characterized set of cancer cell lines from the NCI60 panel. Optimization of PCR assay design and cycling conditions resulted in a high enrichment efficiency. We provide proof of a high mutation rediscovery rate and have included technical replicates to enable SNP calling validation demonstrating the high reproducibility of our enrichment platform. Conclusions Here we present our custom developed quantitative PCR based target enrichment platform. Using highly parallel nanoliter singleplex PCR reactions makes this a flexible and efficient platform. The high mutation validation rate shows this platform’s promise as a targeted resequencing method for multi-gene routine sequencing diagnostics. PMID:24612714

2014-01-01

407

External Photoevaporation of the Solar Nebula: Jupiter's Noble Gas Enrichments  

NASA Astrophysics Data System (ADS)

We present a model explaining the elemental enrichments in Jupiter's atmosphere, particularly the noble gases Ar, Kr, and Xe. While He, Ne, and O are depleted, seven other elements show similar enrichments (~3 times solar, relative to H). Being volatile, Ar is difficult to fractionate from H2. We argue that external photoevaporation by far-ultraviolet (FUV) radiation from nearby massive stars removed H2, He, and Ne from the solar nebula, but Ar and other species were retained because photoevaporation occurred at large heliocentric distances where temperatures were cold enough (lsim 30 K) to trap them in amorphous water ice. As the solar nebula lost H, it became relatively and uniformly enriched in other species. Our model improves on the similar model of Guillot & Hueso. We recognize that cold temperatures alone do not trap volatiles; continuous water vapor production is also necessary. We demonstrate that FUV fluxes that photoevaporated the disk generated sufficient water vapor in regions <~ 30 K to trap gas-phase species in amorphous water ice in solar proportions. We find more efficient chemical fractionation in the outer disk: whereas the model of Guillot & Hueso predicts a factor of three enrichment when only <2% of the disk mass remains, we find the same enrichments when 30% of the disk mass remains. Finally, we predict the presence of ~0.1 M ? of water vapor in the outer solar nebula and protoplanetary disks in H II regions.

Monga, Nikhil; Desch, Steven

2015-01-01

408

A short and valid measure of work-family enrichment.  

PubMed

The stream of research concerning work-family enrichment has generated a significant body of research because it plays an important role in occupational health (Masuda, McNall, Allen, & Nicklin, 2012). work-family enrichment has been defined as "the extent to which experiences in one role improve the quality of life in the other role" (Greenhaus & Powell, 2006, p. 73). Within work-family enrichment, there are two directions: work to family and family to work. Carlson, Kacmar, Wayne, and Grzywacz (2006) developed an 18-item scale to measure this construct. Although the scale has been shown to be both reliable and valid, it also requires work-family researchers to include a proportionally large number of items to capture this construct in a study. The goal of the current study was to isolate a subset of the items in this measure that produces results similar to the full version thereby providing a more streamlined scale for researchers. Using a five-sample study that follows the scale reduction procedures offered by Stanton, Sinar, Balzer, and Smith (2002), we provide evidence that scales containing only three items for each direction of enrichment produce results equivalent to the full scale with respect to reliability and discriminant, convergent, and predictive validity. Reducing the original scale by two thirds, without losing explanatory power, allows scholars to measure enrichment in the work and family domains more efficiently, which should help minimize survey time, lower refusal rates, and generate less missing data. PMID:24447219

Kacmar, K Michele; Crawford, Wayne S; Carlson, Dawn S; Ferguson, Merideth; Whitten, Dwayne

2014-01-01

409

Comparison of several types of enrichment for captive felids.  

PubMed

Enrichment can increase the complexity of the captive environment and possibly enhance captive animals' well-being by stimulating active behaviors and reducing stereotypical behaviors commonly seen in zoo felids. In this study, three different enrichment items were added to outdoor enclosures of felids at the Montgomery Zoo to test their effects on activity levels and stereotypic pacing. Bones, frozen fish, and spices (cinnamon, chili powder, and cumin) were presented over a 3-month period to six species of felids: cheetah, cougar, jaguar, lion, ocelot, and tiger. Proportion of time spent engaging in active behaviors and stereotypic pacing were compared before, during, and after treatments. All treatments resulted in a significant increase in activity level from baseline (bones: +15.59%; frozen fish: +35.7%; spices: +12.38%). Effects of enrichment items on activity levels were not sustained 7 days after removal. Proportion of time spent pacing significantly decreased during presentation of spices (-21.25%) and frozen fish (-26.58%), but not with the addition of bones. However, only the effect of frozen fish on stereotypic behavior was sustained 7 days after removal of the enrichment item. In conclusion, bones, spices, and frozen fish are inexpensive and easy-to-administer enrichment items that may be used to increase active behaviors of captive felids. Zoo Biol 26:371-381, 2007. (c) 2007 Wiley-Liss, Inc. PMID:19360587

Skibiel, Amy L; Trevino, Heather S; Naugher, Ken

2007-09-01

410

Surface enrichment of niobium on Inconel 718 (100) single crystals  

NASA Astrophysics Data System (ADS)

The surface composition of an Inconel 718 (100) single crystal was investigated by X-ray photoelectron spectroscopy over the temperature range 300 to 1000 K in ultra-high vacuum (UHV). The surface composition of an ion etched surface closely resembled the bulk alloy composition determined by atomic absorption spectroscopy. The composition of the ion etched surface remained close to the bulk composition until the temperature was raised above 800 K. At temperatures above 800 K, a dramatic enrichment of surface niobium (Nb) occurred. The extent of Nb enrichment was highly influenced by the presence of trace amounts of surface or subsurface oxygen. Numerous cycles of ion etching and annealing led to nearly complete removal of oxygen from the surface and subsurface region. Surface enrichment of Nb at high temperatures on these oxygen-free surfaces was greatly reduced. However, extensive Nb enrichment could be easily reintroduced by pre-exposure of the surface to oxygen prior to high-temperature vacuum annealing. The evolution of CO during the high-temperature anneal suggested that oxygen attack of the Nb carbide particles played a role in the mechanism of surface enrichment.

Dwyer, D. J.; Pang, X. J.; Gao, M.; Wei, R. P.

1994-10-01

411

Heavy Ozone Enrichments from ATMOS Infrared Solar Spectra  

NASA Technical Reports Server (NTRS)

Vertical enrichment profiles of stratospheric O-16O-16O-18 and O-16O-18O-16 (hereafter referred to as (668)O3 and (686)O3 respectively) have been derived from space-based solar occultation spectra recorded at 0.01 cm(exp-1) resolution by the ATMOS (Atmospheric Trace MOlecule Spectroscopy) Fourier transform infrared (FTIR) spectrometer. The observations, made during the Spacelab 3 and ATLAS-1, -2, and -3 shuttle missions, cover polar, mid-latitude and tropical regions between 26 to 2.6 mb inclusive (approximately 25 to 41 km). Average enrichments, weighted by molecular (48)O3 density, of (15 +/- 6)% were found for (668)O3 and (10 +/- 7)% for (686)O3. Defining the mixing ratio of (50)O3 as the sum of those for (668)O3 and (686)O3, an enrichment of (13 plus or minus 5)% was found for (50)O3 (1 sigma standard deviation). No latitudinal or vertical gradients were found outside this standard deviation. From a series of ground-based measurements by the ATMOS instrument at Table Mountain, California (34.4 deg N), an average total column (668)O3 enrichment of (17 +/- 4)% (1 sigma standard deviation) was determined, with no significant seasonal variation discernable. Possible biases in the spectral intensities that affect the determination of absolute enrichments are discussed.

Irion, F. W.; Gunson, M. R.; Rinsland, C. P.; Yung, Y. L.; Abrams, M. C.; Chang, A. Y.; Goldman, A.

1996-01-01

412

Gold enrichment and Bi-mineral assemblages in ores: Examples from shield and orogenic areas  

NASA Astrophysics Data System (ADS)

Gold deposits in metamorphic terranes, like their counterparts in hydrothermal areas, commonly contain small quantities of Bi-tellurides/selenides (BTS) or Bi-sulpho-salts (Bi-ss). These mineral groups, although eclectic in character, have the potential to offer real and hitherto-untapped information on processes of ore formation and evolution, since BTS speciation, paragenesis and assemblages lie at the heart of ideas covering mechanisms of Au-enrichment, fluid-driven infiltration and sulphide modularity. A systematic study of the distribution of BTS in Au-enriched ores from 25 deposits in the Fennoscandian/Ukrainian Shields and in European Phanerozoic orogenic belts allows comparison of telluride speciation and association and construction of a qualitative diagram for Bi-telluride stability in fS_2-fO_2 space on the basis of Bi/Te+Se+S (R{Bi/Te}). Tsumoite (BiTe) stability separates reducing environ-ments where Bi-tellurides with R{Bi/Te}>1 are associated with native Bi and maldonite, and oxidizing environments where Bi-tellurides with R{Bi/Te}<1 are associated with Au-Ag-bearing tellurides and native Te. BTS are closely associated with Au, due to incorporation within Bi{melt} above 271^oC. Such melts are powerful "scavengers" for Au, especially at the main fS_2/fO_2 buffers. Overall compositions of Bi-Te-Se-Aumelts, as seen in resultant BTS associations, reflect the reducing/oxidizing character of source fluids. Telluride speciation has implications for discriminating overprinting events, with focus on local Au-enrichment at metamorphic peaks, during retrograde stages in skarn and secondary boiling in porphyry, irrespective of age or deposit type. Unlike tellurides, Bi-ss are not necessarily genetically related to Au-enrich-ment. Instead, speciation and compositional variation relate to primary fluid sources and may be specific to regional/orefield trends. Nevertheless, as many sulphosalts form polysomatic series, they can adjust chemical variation via structural modularity at lattice scale. As in biopyroboles, stacking disorder is seen among members of the same series for two common Bi-ss groups (bismuthinite derivatives, lillianite homologues). In skarn, coherent intergrowths among cuprobismutite homologues and related paderaite are additionally seen as long-range polysomes stabilised by periodic chemical variation. Bi-ss are sensitive pathfinders for diffusion-controlled patterning processes at unstable reaction fronts, predictable phenomena during the switch from prograde to retrograde paths. Recognition of such critical points during ore formation, involving dramatic change in fluid parameters, is crucial for Au-enrichment due to activation of the Bimelt scavenger at such conditions.

Ciobanu, C. L.; Cook, N. J.; Pring, A.

2003-04-01

413

Nuclear material safeguards for enrichments plants: Part 4, Gas Centrifuge Enrichment Plant: Diversion scenarios and IAEA safeguards activities: Safeguards training course  

SciTech Connect

This publication is Part 4 of a safeguards training course in Nuclear Material Safeguards for enrichment plants. This part of the course deals with diversion scenarios and safeguards activities at gas centrifuge enrichment plants.

Not Available

1988-10-01

414

Isolation and Enrichment of Stem Cells  

NASA Astrophysics Data System (ADS)

Stem cells have the potential to revolutionize tissue regeneration and engineering. Both general types of stem cells, those with pluripotent differentiation potential as well as those with multipotent differentiation potential, are of equal interest. They are important tools to further understanding of general cellular processes, to refine industrial applications for drug target discovery and predictive toxicology, and to gain more insights into their potential for tissue regeneration. This chapter provides an overview of existing sorting technologies and protocols, outlines the phenotypic characteristics of a number of different stem cells, and summarizes their potential clinical applications.

Bosio, Andreas; Huppert, Volker; Donath, Susan; Hennemann, Petra; Malchow, Michaela; Heinlein, Uwe A. O.

415

Imbibition flooding with CO?-enriched water  

E-print Network

performance for a typical Austin Chalk field. METHODOLOGY Imbibition flood testing in core samples is a "saturate and soak" process. Core samples are first dried, then saturated with water. After weighing, the sample is saturated with oil down to minimum..., SPE / DOE 12688, ( April 1984 ) pp. 93, 101. 34 APPENDIX 35 CORE SAMPLE DATA TYPE OF CORE: LENGTH: DIAMETER: POROSITY i PORE VOLUME: Sample data sheet Inches. CC MASS WHEN DRY: g MASS WHEN SATURATED IN H20: g IN DIESEL & H20: g AFTER...

Grape, Steven George

1990-01-01

416

N-3 fatty acid enriched eggs and production of egg yolk powders: an increased risk of lipid oxidation?  

PubMed

Lipid oxidation is generally favoured by thermal processing and long-term storage. Oxidised lipids can alter nutritional and sensorial properties of foods. As eggs are widely used in food industries in dried powder form, our aim was to determine whether compositional or processing parameters have an impact on lipid oxidation from the shell eggs up to the dried powders and subsequent storage. Two batches of shell eggs were processed: one issued from hens fed with a standard diet and another receiving a diet enriched in extruded linseed, rich in linolenic acid. The extent of lipid oxidation was evaluated by quantification of conjugated dienes (CD) and malondialdehyde (MDA), but also by assessment of tocopherols, lutein and zeaxanthin losses. Results highlighted the remarkable oxidative stability of control and enriched yolk powders as revealed by a moderate increase of the quantities of CD and MDA, the lack of oxidised cholesterol and small loss of ?-tocopherol. PMID:24491705

Meynier, A; Leborgne, C; Viau, M; Schuck, P; Guichardant, M; Rannou, C; Anton, M

2014-06-15

417

Nitrogen control of 13C enrichment in heterotrophic organs relative to leaves in a landscape-building desert plant species  

NASA Astrophysics Data System (ADS)

A longstanding puzzle in isotope studies of C3 plant species is that heterotrophic plant organs (e.g., stems, roots, seeds, and fruits) tend to be enriched in 13C compared to the autotrophic organ (leaves) that provides them with photosynthate. Our inability to explain this puzzle suggests key deficiencies in understanding post-photosynthetic metabolic processes. It also limits the effectiveness of applications of stable carbon isotope analyses in a variety of scientific disciplines ranging from plant physiology to global carbon cycle studies. To gain insight into this puzzle, we excavated whole plant architectures of Nitraria tangutorum Bobrov, a C3 species that has an exceptional capability of fixing sands and building sand dunes, in two deserts in northwestern China. We systematically and simultaneously measured carbon isotope ratios and nitrogen and phosphorous contents of different parts of the excavated plants. We also determined the seasonal variations in leaf carbon isotope ratios on nearby intact plants of N. tangutorum. We found, for the first time, that higher nitrogen contents in heterotrophic organs were significantly correlated with increased heterotrophic 13C enrichment compared to leaves. However, phosphorous contents had no effect on the enrichment. In addition, new leaves had carbon isotope ratios similar to roots but were progressively depleted in 13C as they matured. We concluded that a nitrogen-mediated process, hypothesized to be the refixation of respiratory CO2 by phosphoenolpyruvate (PEP) carboxylase, was responsible for the differences in 13C enrichment among different heterotrophic organs, while processes such as fractionating foliar metabolism and preferentially loading into phloem of 13C-enriched sugars may contribute to the overall autotrophic-heterotrophic difference in carbon isotope compositions.

Zhang, J.; Gu, L.; Bao, F.; Cao, Y.; Hao, Y.; He, J.; Li, J.; Li, Y.; Ren, Y.; Wang, F.; Wu, R.; Yao, B.; Zhao, Y.; Lin, G.; Wu, B.; Lu, Q.; Meng, P.

2015-01-01

418

Effect of administration of water enriched in O2 by injection or electrolysis on transcutaneous oxygen pressure in anesthetized pigs  

PubMed Central

Background Oral administration of oxygenated water has been shown to improve blood oxygenation and could be an alternate way for oxygen (O2) supply. In this experiment, tissue oxygenation was compared in anesthetized pigs receiving a placebo or water enriched in O2 by injection or a new electrolytic process. Methods Forty-two pigs randomized in three groups received either mineral water as placebo or water enriched in O2 by injection or the electrolytic process (10 mL/kg in the stomach). Hemodynamic parameters, partial pressure of oxygen in the arterial blood (PaO2), skin blood flow, and tissue oxygenation (transcutaneous oxygen pressure, or TcPO2) were monitored during 90 minutes of general anesthesia. Absorption and tissue distribution of the three waters administered were assessed using dilution of deuterium oxide. Results Mean arterial pressure, heart rate, PaO2, arteriovenous oxygen difference, and water absorption from the gut were not significantly different among the three groups. The deuterium to protium ratio was also similar in the plasma, skin, and muscle at the end of the protocol. Skin blood flow decreased in the three groups. TcPO2 slowly decreased over the last 60 minutes of the experiment in the three groups, but when compared to the control group, the values remained significantly higher in animals that received the water enriched in O2 by electrolysis. Conclusions In this protocol, water enriched in O2 by electrolysis lessened the decline of peripheral tissue oxygenation. This observation is compatible with the claim that the electrolytic process generates water clathrates which trap O2 and facilitate O2 diffusion along pressure gradients. Potential applications of O2-enriched water include an alternate method of oxygen supply. PMID:25210438

Charton, Antoine; Péronnet, François; Doutreleau, Stephane; Lonsdorfer, Evelyne; Klein, Alexis; Jimenez, Liliana; Geny, Bernard; Diemunsch, Pierre; Richard, Ruddy

2014-01-01

419

Stimuli-responsive reagent system for enabling microfluidic immunoassays with biomarker purification and enrichment.  

PubMed

Immunoassays have been translated into microfluidic device formats, but significant challenges relating to upstream sample processing still limit their applications. Here, stimuli-responsive polymer-antibody conjugates are utilized in a microfluidic immunoassay to enable rapid biomarker purification and enrichment as well as sensitive detection. The conjugates were constructed by covalently grafting poly(N-isopropylacrylamide) (PNIPAAm), a thermally responsive polymer, to the lysine residues of anti-prostate specific antigen (PSA) Immunoglobulin G (IgG) using carbodiimide chemistry via the polymer end-carboxylate. The antibody-PNIPAAm (capture) conjugates and antibody-alkaline phosphatase (detection) conjugates formed sandwich immunocomplexes via PSA binding in 50% human plasma. The complexes were loaded into a recirculating poly(dimethylsiloxane) microreactor, equipped with micropumps and transverse flow features, for subsequent separation, enrichment, and quantification. The immunocomplexes were captured by heating the solution to 39 °C, mixed over the transverse features for 2 min, and washed with warm buffer. In one approach, the assay utilized immunocomplex solution that was contained in an 80 nL microreactor, which was loaded with solution at room temperature and subsequently heated to 39 °C. The assay took 25 min and resulted in 37 pM PSA limit of detection (LOD), which is comparable to a plate ELISA employing the same antibody pair. In another approach, the microreactor was preheated to 39 °C, and immunocomplex solution was flowed through the reactor, mixed, and washed. When the specimen volume was increased to 7.5 ?L by repeating the capture process three times, the higher specimen volume led to immunocomplex enrichment within the microreactor. The resulting assay LOD was 0.5 pM, which is 2 orders of magnitude lower than the plate ELISA. Both approaches generate antigen specific signal over a clinically significant range. The sample processing capabilities and subsequent utility in a biomarker assay demonstrate the opportunity for stimuli-responsive polymer-protein conjugates in novel diagnostic technologies. PMID:25405605

Hoffman, John M; Stayton, Patrick S; Hoffman, Allan S; Lai, James J

2015-01-21

420

Enrichment of 3He and Heavy Ions in Impulsive Solar Flares  

NASA Astrophysics Data System (ADS)

The acceleration of 3He and heavy ions by electromagnetic hydrogen cyclotron waves in a direct single-stage process in impulsive solar flares is investigated analytically and with the help of test particle simulations. We illustrate in detail the mechanism by which a single monochromatic wave can accelerate such ions to MeV and even GeV energies. While somewhat idealized, a monochromatic wave well illustrates the importance of the background magnetic field gradient in the acceleration process. An interesting result of our analysis shows that the acceleration rate is proportional to the magnitude of the magnetic field gradient and is independent of the wave amplitude, while the maximum energy gained increases with decreasing magnetic field gradient and increasing wave amplitude. Heavy ions can also be accelerated by these electromagnetic hydrogen cyclotron waves in a single-stage process by the second or higher harmonic resonance. The acceleration of heavier ions by the same mechanism raises the question of their low enrichment in comparison to much higher enrichment of 3He. The solution is related to the initial small acceleration of the thermal heavy ions at the higher harmonic resonances. The enrichment of the heavy ions increases with the amplitude of the electromagnetic waves and decreases with the plasma density due to Coulomb collisions and absorption of wave energy. Comparison between the rate of cooling of thermal heavy ions due to collisions and heating by waves gives wave intensity and heavy ion ratios which are consistent with observations. The relation between the accelerated heavy ion abundances and their gyrofrequencies in the corona is used to estimate the temperature in the acceleration region. The existence of electromagnetic hydrogen cyclotron waves in flare plasmas is supported by observations in auroral plasmas and by solution of the dispersion relation, which shows that such waves can propagate over long distances along coronal magnetic fields.

Roth, Ilan; Temerin, Michael

1997-03-01

421

Selective Enrichment of Azide-Containing Peptides from Complex Mixtures  

PubMed Central

A general method is described to sequester peptides containing azides from complex peptide mixtures, aimed at facilitating mass spectrometric analysis to study different aspects of proteome dynamics. The enrichment method is based on covalent capture of azide-containing peptides by the azide-reactive cyclooctyne (ARCO) resin and is demonstrated for two different applications. Enrichment of peptides derived from cytochrome c treated with the azide-containing cross-linker bis(succinimidyl)-3-azidomethyl glutarate (BAMG) shows several cross-link containing peptides. Sequestration of peptides derived from an Escherichia coli proteome, pulse labeled with the bio-orthogonal amino acid azidohomoalanine as substitute for methionine, allows identification of numerous newly synthesized proteins. Furthermore, the method is found to be very specific, as after enrichment over 87% of all peptides contain (modified) azidohomoalanine. PMID:19402736

Nessen, Merel A.; Kramer, Gertjan; Back, JaapWillem; Baskin, Jeremy M.; Smeenk, Linde E. J.; de Koning, Leo J.; van Maarseveen, Jan H.; de Jong, Luitzen; Bertozzi, Carolyn R.; Hiemstra, Henk; de Koster, Chris G.

2009-01-01

422

Electron Spin Decoherence in Isotope-Enriched Silicon  

NASA Astrophysics Data System (ADS)

Silicon is promising for spin-based quantum computation because nuclear spins, a source of magnetic noise, may be eliminated through isotopic enrichment. Long spin decoherence times T2 have been measured in isotope-enriched silicon but come far short of the T2=2T1 limit. The effect of nuclear spins on T2 is well established. However, the effect of background electron spins from ever present residual phosphorus impurities in silicon can also produce significant decoherence. We study spin decoherence decay as a function of donor concentration, Si29 concentration, and temperature using cluster expansion techniques specifically adapted to the problem of a sparse dipolarly coupled electron spin bath. Our results agree with the existing experimental spin echo data in Si:P and establish the importance of background dopants as the ultimate decoherence mechanism in isotope-enriched silicon.

Witzel, Wayne M.; Carroll, Malcolm S.; Morello, Andrea; Cywi?ski, ?ukasz; Das Sarma, S.

2010-10-01

423

Tritium Enrichment in the Hydration Sphere of Humic Substances  

SciTech Connect

Humic and fulvic acid can be combined under the term 'humic substances' and are natural substances with a complex structure. The structural details are not known, however, due to the functional groups present in these compounds the formation of hydrogen bonds is easily attained. Several humic substances were investigated for their potential use as compounds, which are applicable for tritium enrichment from aqueous solution. For comparison a simple compound, malonic acid, representing only few functional groups was investigated. The experiments were performed using a cryosublimation apparatus, which was run well below equilibrium vapor pressure to avoid any isotope fractionation of HTO and H{sub 2}O. A higher enrichment factor was found for natural humic acid compared to fulvic acid, however, no enrichment could be found for a synthetic humic acid and malonic acid. Interpretation of the results is difficult since no detailed information on the chemical structure of humic substances is known.

Wierczinski, Birgit; Muellen, Guenther; Tuerler, Andreas

2005-07-15

424

External Photoevaporation of the Solar Nebula: Jupiter's Noble Gas Enrichments  

E-print Network

We present a model explaining elemental enrichments in Jupiter's atmosphere, particularly the noble gases Ar, Kr, and Xe. While He, Ne and O are depleted, seven other elements show similar enrichments ($\\sim$3 times solar, relative to H). Being volatile, Ar is difficult to fractionate from ${\\rm H}_{2}$. We argue that external photoevaporation by far ultraviolet (FUV) radiation from nearby massive stars removed ${\\rm H}_{2}$, He, and Ne from the solar nebula, but Ar and other species were retained because photoevaporation occurred at large heliocentric distances where temperatures were cold enough ($\\lt 30$ K) to trap them in amorphous water ice. As the solar nebula lost H it became relatively and uniformly enriched in other species. Our model improves on the similar model of Guillot \\& Hueso (2006). We recognize that cold temperatures alone do not trap volatiles; continuous water vapor production also is necessary. We demonstrate that FUV fluxes that photoevaporated the disk generated sufficient water va...

Monga, Nikhil

2014-01-01

425

Reduced enrichment for research and test reactors: Proceedings  

SciTech Connect

The international effort to develop new research reactor fuel materials and designs based on the use of low-enriched uranium, instead of highly-enriched uranium, has made much progress during the eight years since its inception. To foster direct communication and exchange of ideas among the specialist in this area, the Reduced Enrichment Research and Test Reactor (RERTR) Program, at the Argonne National Laboratory, sponsored this meeting as the ninth of a series which began in 1978. All previous meetings of this series are listed on the facing page. The focus of this meeting was on the LEU fuel demonstration which was in progress at the Oak Ridge Research (ORR) reactor, not far from where the meeting was held. The visit to the ORR, where a silicide LEU fuel with 4.8 g A/cm/sup 3/ was by then in routine use, illustrated how far work has progressed.

Not Available

1988-05-01

426

Biomedical research applications of electromagnetically separated enriched stable isotopes  

NASA Astrophysics Data System (ADS)

The current and projected annual requirements through 1985 for stable isotopes enriched by electromagnetic separation methods were reviewed for applications in various types of biomedical research: (1) medical radiosiotope production, labeled compounds, and potential radio-pharmaceuticals; (2) nutrition, food science, and pharmacology: (3) metallobiochemistry and environmental toxicology; (4) nuclear magnetic resonance, electron paramagnetic resonance, and moessbauer spectroscopy in biochemical, biophysical, and biomedical research; and (5) miscellaneous advances in radioactive and nonradioactive tracer technology. Radioisotopes available from commercial sources or routinely used in clinical nuclear medicine were excluded. Current requirements for enriched stable isotopes in biomedical research are not being satisfied. Severe shortages exist for Mg 26, Ca 43, Zn 70, Se 76, Se 77, Se 78, Pd 102, Cd 111, Cd 113, and Os 190. Many interesting and potentially important investigations in biomedical research require small quantities of specific elements at high isotopic enrichments.

Lambrecht, R. M.

427

Chest wall thickness measurements for enriched uranium: an alternative approach.  

PubMed

The Human Monitoring Laboratory has developed a technique to determine the chest wall thickness of an individual using information from the spectrum produced by internally deposited radionuclides. The technique has been investigated both theoretically and practically using phoswich detectors and the Lawrence Livermore Torso Phantom. The phantom was used with lung sets containing homogeneously distributed 93% enriched uranium, 20% enriched uranium, natural uranium, and 241Am. It was found that a 3-cm chest wall thickness can be estimated to within 9% when measuring 93% enriched uranium. The technique does not work for the latter two radionuclides because of an insufficient separation in the photon energies and poor resolution of the phoswich detectors. The technique is only of value for activity levels well above the detection limit. PMID:8175366

Kramer, G H; Puscalau, M

1994-05-01

428

Development of an economic model to assess the feasibility of the nuclear industry to produce, handle, and operate commercial fuel with enrichments greater than 5-wt% uranium-235 for PWRs in the United States  

NASA Astrophysics Data System (ADS)

The nuclear power industry in the United States is currently limited to 5-wt% U235 fuel. Increasing this enrichment limit would enable utilities to decrease the number of spent fuel assemblies, allow upgrades in reactor power, have more flexibility in fuel cycle lengths, and allow for the development of advanced fuel designs. Any increase in fuel enrichments requires an extensive analysis of the entire fuel cycle including